Immunoglobulin G/immunoglobulin M autoantibody ratios in incomplete systemic lupus erythematosus

OBJECTIVE

Immunoglobulin G (IgG) autoantibodies in systemic lupus erythematosus (SLE) are considered pathogenic, whereas immunoglobulin M (IgM) autoantibodies may have protective effects. The aim of this study was to identify whether IgG/IgM autoantibody ratios differ between patients with incomplete systemic lupus erythematosus (iSLE), patients with SLE, and healthy controls (HCs), and whether IgG/IgM autoantibody ratios relate to progression from iSLE to SLE.

METHOD

This prospective cohort study included 34 iSLE patients, 41 SLE patients, and 11 HCs. IgG and IgM anti-dsDNA, anti-Ro52, and anti-Ro60 were measured by fluoro-enzyme immunoassay in serum samples obtained at baseline in all groups and in follow-up samples of up to 5 years for iSLE patients. Correlations between IgG/IgM autoantibody ratios, interferon signature, and clinical parameters were also assessed.

RESULTS

At baseline, IgG anti-dsDNA, anti-Ro52, anti-Ro60, and IgM anti-dsDNA were elevated in iSLE and SLE patients. IgG/IgM anti-dsDNA and anti-Ro52 ratios were similar between groups, while IgG/IgM anti-Ro60 ratios were significantly elevated in iSLE and SLE patients compared to HCs. IgG/IgM autoantibody ratios were not correlated with interferon signature or clinical parameters. IgG/IgM ratios at baseline were similar and remained relatively stable during a median follow-up of 18 months in non-progressors and six iSLE patients who progressed to SLE.

CONCLUSION

IgG anti-dsDNA, anti-Ro52, anti-Ro60, and IgM anti-dsDNA were elevated in iSLE and SLE patients, which was not apparent from the respective IgG/IgM ratios only. IgG/IgM autoantibody ratios remained relatively stable over up to 5 years in iSLE non-progressors and six patients who progressed to SLE.

Optimal diagnostic approach for using CT-derived quantitative flow ratio in patients with stenosis on coronary computed tomography angiography

BACKGROUND

Coronary computed tomography angiography (CCTA)-derived quantitative flow ratio (CT-QFR) is an on-site non-invasive technique estimating invasive fractional flow reserve (FFR). This study assesses the diagnostic performance of using most distal CT-QFR versus lesion-specific CT-QFR approach for identifying hemodynamically obstructive coronary artery disease (CAD).

METHODS

Prospectively enrolled de novo chest pain patients (n ​= ​445) with ≥50 ​% visual diameter stenosis on CCTA were referred for invasive evaluation. On-site CT-QFR was analyzed post-hoc blinded to angiographic data and obtained as both most distal (MD-QFR) and lesion-specific CT-QFR (LS-QFR). Abnormal CT-QFR was defined as ≤0.80. Hemodynamically obstructive CAD was defined as invasive FFR ≤0.80 or ≥70 ​% diameter stenosis by 3D-quantitative coronary angiography.

RESULTS

In total 404/445 patients had paired CT-QFR and invasive analyses of whom 149/404 (37 ​%) had hemodynamically obstructive CAD. MD-QFR and LS-QFR classified 188 (47 ​%) and 165 (41 ​%) patients as abnormal, respectively. Areas under the receiver-operating characteristic curve for MD-QFR was 0.83 vs. 0.85 for LS-QFR, p ​= ​0.01. Sensitivities for MD-QFR and LS-QFR were 80 ​% (95%CI: 73-86) vs. 77 ​% (95%CI: 69-83), p ​= ​0.03, respectively, and specificities were 73 ​% (95%CI: 67-78) vs. 80 ​% (95%CI: 75-85), p ​< ​0.01, respectively. Positive predictive values for MD-QFR and LS-QFR were 63 ​% vs. 69 ​%, p ​< ​0.01, respectively, and negative predictive values for MD-QFR and LS-QFR were 86 ​% vs. 85 ​%, p ​= ​0.39, respectively).

CONCLUSION

Using a lesion-specific CT-QFR approach has superior discrimination of hemodynamically obstructive CAD compared to a most distal CT-QFR approach. CT-QFR identified most cases of hemodynamically obstructive CAD while a normal CT-QFR excluded hemodynamically obstructive CAD in the majority of patients.

Impact of Absolute Myocardial Blood Flow Quantification on the Diagnostic Performance of PET-Based Perfusion Scans Using 82Rubidium

BACKGROUND

Guidelines propose the inclusion of quantitative measurements from 82Rubidium positron emission tomography (RbPET) to discriminate obstructive coronary artery disease (CAD). However, the effect on diagnostic accuracy is unknown. The aim was to investigate the optimal RbPET reading algorithm for improved identification of obstructive CAD.

METHODS

Prospectively enrolled patients (N=400) underwent RbPET and invasive coronary angiography with fractional flow reserve and quantitative coronary angiography. Quantitative measurements (myocardial blood flow (MBF), MBF reserve, transient ischemic dilatation) by RbPET were step-wisely added to a qualitative assessment by the summed stress score based on their diagnostic accuracy of obstructive CAD by invasive coronary angiography-fractional flow reserve. Prespecified cutoffs were summed stress score ≥4, hyperemic MBF 2.00 mL/g per min, and MBF reserve 1.80, respectively. Hemodynamically obstructive CAD was defined as >90% diameter stenosis or invasive coronary angiography-fractional flow reserve ≤0.80, and sensitivity analyses included a clinically relevant reference of anatomically severe CAD (>70% diameter stenosis by invasive coronary angiography-quantitative coronary angiography).

RESULTS

Hemodynamically obstructive CAD was present in 170/400 (42.5%) patients. Stand-alone summed stress score showed a sensitivity and specificity of 57% and 93%, respectively, while hyperemic MBF showed similar sensitivity (61%, P=0.57) but lower specificity (85%, P=0.008). With increased discrimination by receiver-operating characteristic curves (0.78 versus 0.85; P<0.001), combining summed stress score, MBF and MBF reserve showed the highest sensitivity of 77% but lower specificity of 74% (P<0.001 for both comparisons). Against anatomically severe CAD, all measures independently yielded high discrimination ≥0.90 with increased sensitivity and lower specificity by additional quantification.

CONCLUSIONS

The inclusion of quantitative measurements to a RbPET read increases in the identification of obstructive CAD.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03481712.

Instantaneous wave free ratio vs. fractional flow reserve and 5-year mortality: iFR SWEDEHEART and DEFINE FLAIR

BACKGROUND AND AIMS

Guidelines recommend revascularization of intermediate epicardial artery stenosis to be guided by evidence of ischaemia. Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are equally recommended. Individual 5-year results of two major randomized trials comparing FFR with iFR-guided revascularization suggested increased all-cause mortality following iFR-guided revascularization. The aim of this study was a study-level meta-analysis of the 5-year outcome data in iFR-SWEDEHEART (NCT02166736) and DEFINE-FLAIR (NCT02053038).

METHODS

Composite of major adverse cardiovascular events (MACE) and its individual components [all-cause death, myocardial infarction (MI), and unplanned revascularisation] were analysed. Raw Kaplan-Meier estimates, numbers at risk, and number of events were extracted at 5-year follow-up and analysed using the ipdfc package (Stata version 18, StataCorp, College Station, TX, USA).

RESULTS

In total, iFR and FFR-guided revascularization was performed in 2254 and 2257 patients, respectively. Revascularization was more often deferred in the iFR group [n = 1128 (50.0%)] vs. the FFR group [n = 1021 (45.2%); P = .001]. In the iFR-guided group, the number of deaths, MACE, unplanned revascularization, and MI was 188 (8.3%), 484 (21.5%), 235 (10.4%), and 123 (5.5%) vs. 143 (6.3%), 420 (18.6%), 241 (10.7%), and 123 (5.4%) in the FFR group. Hazard ratio [95% confidence interval (CI)] estimates for MACE were 1.18 [1.04; 1.34], all-cause mortality 1.34 [1.08; 1.67], unplanned revascularization 0.99 [0.83; 1.19], and MI 1.02 [0.80; 1.32].

CONCLUSIONS

Five-year all-cause mortality and MACE rates were increased with revascularization guided by iFR compared to FFR. Rates of unplanned revascularization and MI were equal in the two groups.

Coronary Artery Stenosis Evaluation by Angiography-Derived FFR: Validation by Positron Emission Tomography and Invasive Thermodilution

BACKGROUND

Fractional flow reserve (FFR) derived from invasive coronary angiography (QFR) is promising for evaluation of intermediate coronary artery stenosis.

OBJECTIVES

The authors aimed to compare the diagnostic performance of QFR and the guideline-recommended invasive FFR using 82Rubidium positron emission tomography (82Rb-PET) myocardial perfusion imaging as reference standard.

METHODS

This is a prospective, observational study of symptomatic patients with suspected obstructive coronary artery disease on coronary computed tomography angiography (≥50% diameter stenosis in ≥1 vessel). All patients were referred to 82Rb-PET and invasive coronary angiography with FFR and QFR assessment of all intermediate (30%-90% diameter stenosis) stenoses. Main analyses included a comparison of the ability of QFR and FFR to identify reduced myocardial blood flow (<2 mL/g/min) during vasodilation and/or relative perfusion abnormalities (summed stress score ≥4 in ≥2 adjacent segments).

RESULTS

A total of 250 patients (320 vessels) with indication for invasive physiological assessment were included. The continuous relationship of 82Rb-PET stress myocardial blood flow per 0.10 increase in FFR was +0.14 mL/g/min (95% CI: 0.07-0.21 mL/g/min) and +0.08 mL/g/min (95% CI: 0.02-0.14 mL/g/min) per 0.10 QFR increase. Using 82Rb-PET as reference, QFR and FFR had similar diagnostic performance on both a per-patient level (accuracy: 73%; 95% CI: 67%-79%; vs accuracy: 71%; 95% CI: 64%-78%) and per-vessel level (accuracy: 70%; 95% CI: 64%-75%; vs accuracy: 68%; 95% CI: 62%-73%). The per-vessel feasibility was 84% (95% CI: 80%-88%) for QFR and 88% (95% CI: 85%-92%) for FFR by intention-to-diagnose analysis.

CONCLUSIONS

With 82Rb-PET as reference modality, the wire-free QFR solution showed similar diagnostic accuracy as invasive FFR in evaluation of intermediate coronary stenosis. (DAN-NICAD - Danish Study of Non-Invasive Diagnostic Testing in Coronary Artery Disease; NCT02264717).

Danish study of Non-Invasive Testing in Coronary Artery Disease 3 (Dan-NICAD 3): study design of a controlled study on optimal diagnostic strategy

INTRODUCTION

Current guideline recommend functional imaging for myocardial ischaemia if coronary CT angiography (CTA) has shown coronary artery disease (CAD) of uncertain functional significance. However, diagnostic accuracy of selective myocardial perfusion imaging after coronary CTA is currently unclear. The Danish study of Non-Invasive testing in Coronary Artery Disease 3 trial is designed to evaluate head to head the diagnostic accuracy of myocardial perfusion imaging with positron emission tomography (PET) using the tracers ⁸²Rubidium (⁸²Rb-PET) compared with oxygen-15 labelled water PET (¹⁵O-water-PET) in patients with symptoms of obstructive CAD and a coronary CT scan with suspected obstructive CAD.

METHODS AND ANALYSIS

This prospective, multicentre, cross-sectional study will include approximately 1000 symptomatic patients without previous CAD. Patients are included after referral to coronary CTA. All patients undergo a structured interview and blood is sampled for genetic and proteomic analysis and a coronary CTA. Patients with possible obstructive CAD at coronary CTA are examined with both ⁸²Rb-PET, ¹⁵O-water-PET and invasive coronary angiography with three-vessel fractional flow reserve and thermodilution measurements of coronary flow reserve. After enrolment, patients are followed with Seattle Angina Questionnaires and follow-up PET scans in patients with an initially abnormal PET scan and for cardiovascular events in 10 years.

ETHICS AND DISSEMINATION

Ethical approval was obtained from Danish regional committee on health research ethics. Written informed consent will be provided by all study participants. Results of this study will be disseminated via articles in international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04707859.

Quantitative flow ratio versus fractional flow reserve for guiding percutaneous coronary intervention: design and rationale of the randomised FAVOR III Europe Japan trial

Quantitative flow ratio (QFR) is a computation of fractional flow reserve (FFR) based on invasive coronary angiographic images. Calculating QFR is less invasive than measuring FFR and may be associated with lower costs. Current evidence supports the call for an adequately powered randomised comparison of QFR and FFR for the evaluation of intermediate coronary stenosis. The aim of the FAVOR III Europe Japan trial is to investigate if a QFR-based diagnostic strategy yields a non-inferior 12-month clinical outcome compared with a standard FFR-guided strategy in the evaluation of patients with intermediary coronary stenosis. FAVOR III Europe Japan is an investigator-initiated, randomised, clinical outcome, non-inferiority trial scheduled to randomise 2,000 patients with either 1) stable angina pectoris and intermediate coronary stenosis, or 2) indications for functional assessment of at least 1 non-culprit lesion after acute myocardial infarction. Up to 40 international centres will randomise patients to either a QFR-based or a standard FFR-based diagnostic strategy. The primary endpoint of major adverse cardiovascular events is a composite of all-cause mortality, any myocardial infarction, and any unplanned coronary revascularisation at 12 months. QFR could emerge as an adenosine- and wire-free alternative to FFR, making the functional evaluation of intermediary coronary stenosis less invasive and more cost-effective.

Diagnostic accuracy of optical flow ratio: an individual patient-data meta-analysis

BACKGROUND

Optical flow ratio (OFR) is a novel method for the fast computation of fractional flow reserve (FFR) from optical coherence tomography.

AIMS

We aimed to evaluate the diagnostic accuracy of OFR in assessing intermediate coronary stenosis using wire-based FFR as the reference.

METHODS

We performed an individual patient-level meta-analysis of all available studies with paired OFR and FFR assessments. The primary outcome was vessel-level diagnostic concordance of the OFR and FFR, using a cut-off of ≤0.80 to define ischaemia and ≤0.90 to define suboptimal post-percutaneous coronary intervention (PCI) physiology. This meta-analysis was registered in PROSPERO (CRD42021287726).

RESULTS

Five studies were finally included, providing 574 patients and 626 vessels (404 pre-PCI and 222 post-PCI) with paired OFR and FFR from 9 international centres. Vessel-level diagnostic concordance of the OFR and FFR was 91% (95% confidence interval [CI]: 88%-94%), 87% (95% CI: 82%-91%), and 90% (95% CI: 87%-92%) in pre-PCI, post-PCI, and overall, respectively. The overall sensitivity, specificity, and positive and negative predictive values were 84% (95% CI: 79%-88%), 94% (95% CI: 92%-96%), 90% (95% CI: 86%-93%), and 89% (95% CI: 86%-92%), respectively. Multivariate logistic regression indicated that a low pullback speed (odds ratio [OR] 7.02, 95% CI: 1.68-29.43; p=0.008) was associated with a higher risk of obtaining OFR values at least 0.10 higher than FFR. Increasing the minimal lumen area was associated with a lower risk of obtaining an OFR at least 0.10 lower than FFR (OR 0.39, 95% CI: 0.18-0.82; p=0.013).

CONCLUSIONS

This individual patient data meta-analysis demonstrated a high diagnostic accuracy of OFR. OFR has the potential to provide an improved integration of intracoronary imaging and physiological assessment for the accurate evaluation of coronary artery disease.

Likelihood reclassification by an acoustic-based score in suspected coronary artery disease

OBJECTIVE

Validation studies of the 2019 European Society of Cardiology pretest probability model (ESC-PTP) for coronary artery disease (CAD) report that 35%-40% of patients have low pretest probability (ESC-PTP 5% to <15%). Acoustic detection of coronary stenoses could potentially improve clinical likelihood stratification. Aims were to (1) investigate the diagnostic performance of an acoustic-based CAD score and (2) study the reclassification potential of a dual likelihood strategy by the ESC-PTP and a CAD score.

METHODS

Consecutive patients (n=1683) with stable angina symptoms referred for coronary CT angiography (CTA) underwent heart sound analyses by an acoustic CAD-score device. All patients with ≥50% luminal stenosis in any coronary segment at coronary CTA were referred to investigation with invasive coronary angiography (ICA) with fractional flow reserve (FFR).A predefined CAD-score cut-off ≤20 was used to rule out obstructive CAD.

RESULTS

In total, 439 patients (26%) had ≥50% luminal stenosis on coronary CTA. The subsequent ICA with FFR showed obstructive CAD in 199 patients (11.8%). Using the ≤20 CAD-score cut-off for obstructive CAD rule-out, sensitivity was 85.4% (95% CI 79.7 to 90.0), specificity 40.4% (95% CI 37.9 to 42.9), positive predictive value 16.1% (95% CI 13.9 to 18.5) and negative predictive value 95.4% (95% CI 93.4 to 96.9) in all patients. Applying the cut-off in ESC-PTP 5% to <15% patients, 316 patients (48%) were down-classified to very-low likelihood. The obstructive CAD prevalence was 3.5% in this group.

CONCLUSION

In a large contemporary cohort of patients with low CAD likelihood, the additional use of an acoustic rule-out device showed a clear potential to downgrade likelihood and could supplement current strategies for likelihood assessment to avoid unnecessary testing.

TRIAL REGISTRATION NUMBER

NCT03481712.

Predictive value of post-percutaneous coronary intervention fractional flow reserve: a systematic review and meta-analysis

AIMS

We aimed to investigate the relationship between post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) and clinical outcome using a systematic review with a study-level meta-analysis.

METHODS AND RESULTS

MEDLINE, Embase, and CENTRAL were systematically searched for articles with clinical follow-up reporting mean or median final post-PCI FFR. The main outcome was a composite of major adverse cardiac events (MACE) including all-cause death, myocardial infarction (MI), and target vessel revascularization (TVR). Meta-regression analyses were performed on mean post-PCI FFR values. A total of 62 studies with 12 340 patients and 12 923 stented vessels were included, with follow-ups ranging from 1 to 89 months. Post-PCI FFR was not continuously associated with the rate of 1-year MACE or 1-year TVR using meta-regression models accounting for heterogeneous follow-up lengths. For studies comparing high vs. low post-PCI FFR, low post-PCI FFR was associated with high risk ratio for MACE {1.97 [95% confidence interval (CI):1.45-2.67]}, all-cause death [1.59 (95% CI: 1.08-2.34)], MI [3.18 (95% CI: 1.84-5.50)], TVR [2.08 (95% CI: 1.63-2.65)] and angina status [2.50 (95% CI: 1.53-4.06)] using different optimal cut-off values spanning from 0.80 to 0.95.

CONCLUSION

We found no clear continuous association between post-PCI FFR and clinical outcomes in this systematic study-level meta-analysis. In a subset of studies investigating binary classification, high post-PCI FFR was associated with a better clinical outcome than low post-PCI FFR.We investigated the relationship between post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) and rate of major adverse cardiac events (MACE), including all-cause death, myocardial infarction (MI), and target vessel revascularization (TVR), using a systematic review and study-level meta-analysis, pooling 12 340 patients from 62 studies. Mean post-PCI FFR was not continuously associated with a 1-year MACE rate accounting for heterogenous follow-up lengths. Still, the risk ratio favoured high post-PCI FFR for reduced MACE, all-cause death, MI, TVR, and better angina status using different cut-offs.

Second-Line Myocardial Perfusion Imaging to Detect Obstructive Stenosis: Head-to-Head Comparison of CMR and PET

BACKGROUND

Guidelines recommend verification of myocardial ischemia by selective second-line myocardial perfusion imaging (MPI) following a coronary computed tomography angiography (CTA) with suspected obstructive coronary artery disease (CAD). Head-to-head data on the diagnostic performance of different MPI modalities in this setting are sparse.

OBJECTIVES

The authors sought to compare, head-to-head, the diagnostic performance of selective MPI by 3.0-T cardiac magnetic resonance (CMR) and ⁸²rubidium positron emission tomography (RbPET) in patients with suspected obstructive stenosis at coronary CTA using invasive coronary angiography (ICA) with fractional flow reserve (FFR) as reference.

METHODS

Consecutive patients (n = 1,732, mean age: 59.1 ± 9.5, 57.2% men) referred for coronary CTA with symptoms suggestive of obstructive CAD were included. Patients with suspected stenosis were referred for both CMR and RbPET and subsequently ICA. Obstructive CAD was defined as FFR ≤0.80 or >90% diameter stenosis by visual assessment.

RESULTS

In total, 445 patients had suspected stenosis on coronary CTA. Of these, 372 patients completed both CMR, RbPET and subsequent ICA with FFR. Hemodynamically obstructive CAD was identified in 164 of 372 (44.1%) patients. Sensitivities for CMR and RbPET were 59% (95% CI: 51%-67%) and 64% (95% CI: 56%-71%); P = 0.21, respectively, and specificities 84% (95% CI: 78%-89%) and 89% (95% CI: 84%-93%]); P = 0.08, respectively. Overall accuracy was higher for RbPET compared with CMR (73% vs 78%; P = 0.03).

CONCLUSIONS

In patients with suspected obstructive stenosis at coronary CTA, CMR, and RbPET show similar and moderate sensitivities but high specificities compared with ICA with FFR. This patient group represents a diagnostic challenge with frequent mismatch between advanced MPI tests and invasive measurements. (Danish Study of Non-Invasive Diagnostic Testing in Coronary Artery Disease 2 [Dan-NICAD 2]; NCT03481712).

Diagnostic performance of on-site computation of quantitative flow ratio by a coronary computed tomography angiography based algorithm: comparison of distal and lesion-specific measurements

Introduction

Guidelines recommend secondary ischemia assessment following a coronary computed tomography angiography (CTA) with suspected obstructive coronary artery disease (CAD). Coronary CTA-derived quantitative flow ratio (CT-QFR) is an on-site technique performed on acquired CTA images that estimates the functional severity of a coronary stenosis. However, CT-QFR measurements are available throughout the coronary vessel with no clear recommendations as to which specific values should be used for identifying obstructive CAD, e.g. most distal or lesion-specific values.

Purpose

First, to investigate the feasibility of CT-QFR and the correlation and agreement with invasive fractional flow reserve (FFR). Secondly, to compare the diagnostic performance of distal versus lesion-specific CT-QFR for identifying obstructive CAD defined by invasive coronary angiography (ICA) with FFR.

Methods

A total of 1732 prospectively included patients with symptoms suggestive of CAD referred for CTA were included. All patients with ≥50% diameter stenosis (DS) on CTA were subsequently referred for ICA with conditional FFR in lesions with 30–89%DS. Obstructive CAD was defined by ICA as FFR ≤0.80 or high-grade stenosis by visual assessment (≥90%DS). A blinded analysis of CT-QFR was performed in patients referred to ICA with measurements at the distal end of a vessel (distal CT-QFR) and 1 cm distal to stenotic lesions on CTA (lesion-specific). CT-QFR ≤0.80 was defined as abnormal. For correlation analyses to invasive FFR, CT-QFR was assessed corresponding to the position of the invasive pressure sensor.

Results

In total, 445/1732 (25%) patients had suspected obstructive CAD at CTA and underwent subsequent ICA. CT-QFR analysis was feasible in 423/445 (95%) patients. CT-QFR correlated (Pearson's rho 0.54, p&lt;0.001) and agreed (mean difference –0.02±0.09) to FFR with CT-QFR overestimating FFR (Fig. 1). Obstructive CAD was identified in 190/423 (44%) patients by ICA. Distal and lesion-specific CT-QFR classified 196 (46%) and 171 (40%) patients as abnormal, respectively. Areas under the receiver-operating characteristic curves for distal versus lesion-specific CT-QFR were similar (0.86 (95% CI: 0.82–0.89) vs. 0.86 (0.82–0.90), p=0.80). Sensitivities for distal and lesion-specific CT-QFR were 78% (95% CI: 71–84) vs. 74% (67–80), p=0.01, respectively, and specificities 79% (95% CI: 74–84) vs. 87% (82–91), p&lt;0.01, respectively. Distal and lesion-specific CT-QFR had similar diagnostic accuracy (79 (95% CI: 75–83), vs. 81 (77–85), p=0.07) (Fig. 2).

Conclusion

In patients with suspected obstructive CAD on CTA, non-invasive estimation of FFR using CT-QFR is feasible with moderate correlation and good agreement with invasive FFR. Overall diagnostic performance of distal and lesion-specific values for discriminating obstructive CAD by invasive FFR are similar. The use of CT-QFR could therefore potentially reduce the need for referral to invasive angiography after CTA.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Aarhus UniversityRegion Mid Jutland

Comparison of second-line on-site computed quantitative flow ratio from coronary computed tomography angiography to PET perfusion imaging for detecting obstructive coronary artery disease

Introduction

In patients with suspected obstructive coronary artery disease (CAD) on coronary computed tomography (CTA), guidelines endorse second-line selective testing for hemodynamic evaluation of suspected CAD. A variety of non-invasive modalities are available, and myocardial perfusion imaging with Rubidium-82 positron emission tomography (PET) is an established method with high diagnostic performance. Recently, an on-site method estimating computed tomography-derived quantitative flow ratio (CT-QFR) showed promising results for discriminating obstructive CAD. However, no study has compared the diagnostic performances of PET and CT-QFR.

Purpose

To assess a possible non-inferiority of CT-QFR compared to PET in patients with suspected obstructive CAD at CTA using invasive coronary angiography (ICA) with fractional flow reserve (FFR) as reference.

Methods

Patients (n=1732, 57% males, age 59±9.5) referred on a clinical indication with symptoms suggestive of obstructive CAD underwent routine CTA. Patients with ≥50% diameter stenosis (DS) on CTA were referred for PET and subsequent ICA with FFR. CT-QFR was analyzed post-hoc blinded to PET and ICA results.

Abnormal CT-QFR was defined as CT-QFR ≤0.80 in any vessel with a diameter ≥1.5mm. An independent core-lab evaluated PET scans as abnormal/normal with optional analyst-dependent application of pre-specified criteria; summed stress score of ≥4 in ≥2 contiguous segments, vessel-specific myocardial blood flow (MBF) &lt;2.00 ml/g/min, global myocardial blood flow reserve ≤1.8, and/or transient ischemic dilatation ratio &gt;1.13. Obstructive CAD was defined as ICA with FFR ≤0.80 or high-grade stenosis (≥90% DS).

Results

In total, 445/1732 patients (25%) had suspected obstructive CAD on CTA of whom 400/445 patients (90%) underwent subsequent PET and ICA. CT-QFR was successfully analysed in 383/400 (96%) patients classifying 174/383 (45%) patients as having disease. In comparison, PET classified 130/383 (34%) patients as having disease. In total, obstructive CAD by ICA with FFR was identified in 162 (42%) patients.

There was no significant difference in area under the receiver-operating characteristic curves for CT-QFR compared to the best performing PET metric (lowest vessel-specific MBF); 0.84 (95% CI 0.80–0.89) vs. 0.81 (0.77–0.85), p=0.19)) (Fig. 1). Overall diagnostic accuracy of CT-QFR versus PET was similar (78% (95% CI 74–82) vs. 77% (72–81), p=0.70. Sensitivities for CT-QFR and PET were 78% (71–84) and 63% (55–70), p&lt;0.01, respectively, and specificities 78% (72–84) and 87% (82–91), p=0.01, respectively (Fig. 2). Three-vessel or left main disease on ICA was correctly identified in 30/31 patients by both CT-QFR and PET.

Conclusion

In patients with suspected obstructive CAD by CTA, second-line CT-QFR was non-inferior to PET for discriminating obstructive CAD by invasive FFR; Although diagnostic accuracy was similar, CT-QFR demonstrated higher sensitivity while PET showed higher specificity

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Aarhus University PhD fellowshipRegion Mid Health Research Foundation

POS0785 EXPRESSION OF MYXOVIRUS RESISTANCE PROTEIN A IN LUPUS NEPHRITIS

Background

Lupus nephritis (LN) is regarded as one of the most severe organ manifestations of systemic lupus erythematosus (SLE) [1]. It has been shown that type I interferons (IFN) are important cytokines in the pathogenesis of SLE and LN and could possibly serve as a histological marker for kidney lesions in LN [2]. However, the direct measurement of type I IFN protein in tissues has remained elusive. Myxovirus resistance protein A (MxA) which is upregulated by IFN-1, can easily be measured, and could be used as a potential biomarker. In addition, dendritic cells are main producers of IFN-1.

Objectives

To investigate the expression of MxA and CD303 which is a plasmacytoid dendritic cells (pDCs) specific marker [3] by immunohistochemical analysis of renal specimens obtained from LN patients and from patients with other types of nephritis.

Methods

LN was diagnosed based on the International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification. In total, 41 renal tissue samples were collected from lupus nephritis including all classes (I-V according to ISN/RPS classification), and compared to 70 biopsies from other forms of nephritis. MxA was detected by immunohistochemistry staining. Scoring of MxA staining was done semi-quantitative for separate structures in nephritis tissues with a range from 0 to 3+. Scoring was based on the intensity of the staining, in which ‘0’ meant no expression; ‘1’: weak expression; ‘2’: moderate expression; and ‘3+’: strong expression. The expression of CD303 was measured by counting the number of CD303 positive cells in the glomerulus or in the tubular interstitium.

Results

The MxA average scores of the total LN group were higher than control specimens especially in distal tubules (Figure 1). The MxA expression in LN classes I, II, and V biopsies was mainly increased compared to tissues of patients with minimal change disease, mesangioproliferative nephritis, and membranous nephropathy (Figure 2a,2b,2d). However, MxA staining was comparable in LN classes III/IV compared to control groups (Figure 2c). The staining of CD303 showed that pDC are more present in tubular interstitium than in glomeruli. Furthermore, CD303-positive cells were highest in LN class IV, but overall numbers of pDCs were higher in controls groups compared to LN groups (Figure 3).

Conclusion

Our data indicate that MxA expression is higher in LN vs. other types of nephritis. These results suggest that MxA could be a potential additional histological marker to establish the diagnosis of lupus nephritis on the kidney biopsy. In contrast to the increased expression of MxA in LN, we found decreased numbers of pDCs. Therefore, it is important to investigate which other cells are the main producers of IFN-1 in further studies.

References

[1]Anders HJ, Saxena R, Zhao MH, et al. Lupus nephritis.[J]. Nat Rev Dis Primers. 2020;6(1):7.

[2]Xue L, Liu L, Huang J, et al. Tumor Necrosis Factor-Like Weak Inducer of Apoptosis Activates Type I Interferon Signals in Lupus Nephritis.[J]. Biomed Res Int. 2017;2017:4927376.

[3]Boiocchi L, Lonardi S, Vermi W, Fisogni S, Facchetti F. BDCA-2 (CD303): a highly specific marker for normal and neoplastic plasmacytoid dendritic cells. Blood 2013;122:296-7.

Disclosure of Interests

None declared

AB0117 IMMUNE CELL IMBALANCES IN PLACENTAS OF SYSTEMIC LUPUS ERYTHEMATOSUS AND SJÖGREN’S SYNDROME PATIENTS

Background

Systemic lupus erythematosus (SLE) and primary Sjögren’s syndrome (pSS) are associated with adverse pregnancy outcomes (APOs) [1,2]. During pregnancy, maternal immune activation is related to a higher risk of hypertension, preeclampsia, preterm labor, and fetal growth restriction in SLE patients [1]. Furthermore, these patients have an increased risk of neonatal lupus due to the transplacental passage of maternal anti-RO/SSA antibodies to the fetus [3]. Nevertheless, there is no compelling evidence about the type of immune cell imbalances in the placenta in patients with SLE and pSS.

Objectives

Identify immunologic imbalances, focusing on interferon (IFN) and immune cell subtypes in placenta tissue of patients with SLE or pSS.

Methods

Retrospective analysis of immune cell composition of paraffin-embedded placental tissue from 6 SLE, 4 pSS, and 12 healthy women was conducted. For each case, one full-thickness sample of normal-appearing parenchyma from the central two-thirds of the placental disc was taken. APOs history and pregnancy outcomes were recorded. Placenta immunohistochemistry stainings were done for myxovirus resistance protein A (MxA, an interferon induced protein), CD3, CD20, CD45 and CD68. Statistical analysis was performed with a non-parametric T-test.

Results

A significantly higher MxA expression in the placenta of SLE and pSS patients compared to healthy controls was observed (Figure 1A). SLE patients had an increased MxA expression in decidua and villi compared with controls, while in pSS patients this increase was found in amnion and villi.

The count of T cells, B cells, total leukocytes, and macrophages in the decidua tissue were comparable between groups (Figure 1B). However, a significantly higher macrophage per total number of cells index was observed in SLE and pSS patients compared to healthy controls (Figure 1C). Only two patients had no APOs. Therefore, no analysis was performed comparing patients with or without APO.

Conclusion

A higher macrophage count and an increased IFN expression were identified in the placentas of SLE and pSS patients. These findings suggest a proinflammatory placental environment that could be related to APOs presentation in patients with SLE and pSS. However, to establish the relation with APOs further studies are needed including more patients especially without APOs.

References

[1]Bundhun PK, Soogund MZ, Huang F. Impact of systemic lupus erythematosus on maternal and fetal outcomes following pregnancy: A meta-analysis of studies published between years 2001-2016. J Autoimmun. 2017;79:17–27.

[2]Elliott B, Spence AR, Czuzoj-Shulman N, Abenhaim HA. Effect of Sjogren’s syndrome on maternal and neonatal outcomes of pregnancy. J Perinat Med. 2019;47(6):637–42.

[3]Zuppa AA, Riccardi R, Frezza S, Gallini F, Luciano RM, Alighieri G, et al. Neonatal lupus: Follow-up in infants with anti-SSA/Ro antibodies and review of the literature. Autoimmun Rev. 2017;16(4):427–32.

Disclosure of Interests

None declared

AB0127 BRONCHOALVEOLAR LAVAGE (BAL) FLUID AND SERUM FROM PATIENTS WITH SYSTEMIC SCLEROSIS WITH INTERSTITIAL LUNG DISEASE (SSc-ILD) PROMOTE A PRO-INFLAMMATORY GENE SIGNATURE IN HUMAN PRIMARY LUNG FIBROBLASTS

Background

While circulating cytokines are frequently investigated in SSc patients, they may also play a role in local tissue, such as the lungs. Although most SSc patients show limited systemic inflammation, some studies have demonstrated that BAL fluid obtained from patients with SSc contains elevated levels of pro-inflammatory and pro-fibrotic cytokines. However, the relevance of the local milieu of the bronchial tree on the development of ILD has not been studied. We hypothesized that the bronchial milieu as represented by BAL fluid will have pro-inflammatory and pro-fibrotic effects on lung fibroblasts as the major effector cells in lung fibrosis. We also anticipated a greater pro-inflammatory and pro-fibrotic effect of BAL fluid obtained from patients with ILD (SSc-ILD) compared to patients without ILD (SSc). Finally, we hypothesized that serum obtained from both SSc-ILD and SSc will have a similar and concordant effect on lung fibroblasts, due to the systemic nature of the disease.

Objectives

To show the differential effect of BAL fluid and serum obtained from SSc patients with and without ILD on mRNA expression of pro-inflammatory and pro-fibrotic markers in human primary lung fibroblasts.

Methods

Serum and BAL fluid were collected from 3 SSc-ILD and 3 without ILD who were all treatment-naïve. ILD diagnosis was based on HRCT and lung function tests. Normal human primary lung fibroblasts were cultured and treated with either BAL fluid (5%) or serum (0.5%) from all individual patients. No treatment (CTRL) or treatment with pooled serum from healthy controls were used as control. After 4h, fibroblasts were harvested in TRIzol. The mRNA expression levels of inflammatory markers (Interleukin-6: IL-6, Interferon gamma-induced protein 10: IP-10), fibrotic markers (Connective Tissue Growth Factor: CTGF, Transforming Growth Factor: TGF-β and Alpha- Smooth Muscle Actin: α-SMA) were assessed using RT-qPCR. Nonparametric Mann-Whitney U test was used for comparison between groups. Correlation between BAL and serum treated fibroblast were calculated for the expression of the markers using Pearson correlation coefficient method.

Results

Fibroblasts treated with either SSc or SSc-ILD BAL fluids showed a significantly higher mRNA expression of IL-6 compared to control (Figure 1 a). The same was observed for IP-10, except for SSc serum which was not significant (Figure 1 b). When comparing the effects of BAL fluids between SSc or SSc-ILD patients, the effect of SSc-ILD BAL fluid was strikingly more profound than observed with SSc on both IL-6 and IP-10 (Figure 1 a,b). Similar effects were seen when fibroblasts were treated with SSc serum, where serum from SSc-ILD resulted in significantly higher expression of IL-6 and IP-10 compared to SSc (Figure 1 a,b). The effect of serum and BAL on IL-6 gene expression were strongly and significantly correlated (r=0.9; P=0.015) while were weakly correlated regarding IP-10 expression (r=0.4; P=0.3) (not shown). The fibrotic markers TGF-β and α-SMA showed no difference in expression in BAL or serum-treated fibroblasts compared to controls (Figure 1 c,d). Only the fibroblasts treated with SSc-ILD serum showed a significant increase in mRNA expression of the early fibrosis marker CTGF when compared to control or SSc serum (Figure 1 e).

Conclusion

We showed a clear pro-inflammatory effect of BAL fluid obtained from patients with SSc on human fibroblasts as demonstrated by mRNA expression of IL-6 and IP-10. This pro-inflammatory effect was 5-10 times more profoundly observed in SSc patients with ILD compared to those without ILD. Similar effects were observed when fibroblasts were treated with serum obtained from the same SSc patients where the BAL fluid and serum of each patient seemed to provoke a concordant pro-inflammatory effect. Although further studies are warranted, our results underline the systemic nature of SSc and provide new insights into the role of and interaction between the local bronchial and systemic milieu in ILD development.

Disclosure of Interests

Yehya Al-Adwi: None declared, Johanna Westra: None declared, Alja J. Stel: None declared, Harry van Goor: None declared, Douwe J Mulder Grant/research support from: Dr. DJ Mulder as an employee of the UMCG received research grants from Sanofi Genzyme which were paid to the UMCG.

AB0659 Recruitment and prevalence of mixed phenotype macrophages is prominent in Bronchoalveolar Lavage (BAL) of Systemic Sclerosis (SSc) patients with Interstitial Lung Disease (ILD)

Background

ILD is a major problem in SSc for which no disease-modifying therapies are available. Many observations suggest monocyte/macrophage involvement in SSc and might be a key component in the development of ILD. Macrophages polarize into M1 and M2 phenotypes and thereby orchestrate inflammation and subsequent fibrosis by responding to and producing a vast array of cytokines and chemokines. Differences in the levels of the chemokines might explain variations in the recruitment and activation of macrophages in affected organs. In SSc, monocytes with a mixed phenotype (expressing both M1 and M2 markers) are prominent in peripheral blood. No previous study has investigated the mixed phenotype macrophages locally on the lung level.

Objectives

a-to measure macrophage-related chemokines in BAL fluid obtained from SSc-ILD and SSc-no-ILD patients.

b-to investigate levels of M1 and M2 macrophage markers in BAL cells obtained from SSc-ILD and SSc-no-ILD patients.

Methods

A cross-sectional study in which BAL procedure was performed on 15 treatment-naïve SSc patients divided into two groups according to lung involvement determined by HRCT and lung function tests: SSc-no-ILD group and SSc-ILD group (Table 1). Levels of chemokines (CCL18, CXCL-10 and CCR2) were analysed using ELISA. mRNA expression levels of CD86 (M1; inflammatory macrophage marker) and CD206 (M2; fibrogenic macrophage marker) in cells isolated from BAL were assessed using RT-qPCR. In addition, immunofluorescence studies and flow cytometry analyses were performed to evaluate the expression of M1 (CD86) or M2 (CD206) markers in BAL macrophages.

Table 1.

Patient characteristics

no ILDILDNumber of patients87Age57 (51-68)60 (53-73)Female75%57%Raynauds phenomenon100%85%Age start of Raynauds36 (22-53)56 (41-66)Age start of non-Raynauds50 (33-60)49 (36-68)Skin thickening50%43%Digital ulcer at this moment0%29%Digital ulcer in the past38%29%Pitting scars38%43%Telangiectasia50%43%Calcinosis13%29%Cardiac25%14%Gastro-intestinal88%43%Kidney0%0%

Results

Macrophages were the predominant immune cell population in BAL of SSc patients (73%). The levels of CCL18, CCR2 and CXCL10 were slightly elevated in the SSc-ILD group compared to the SSc-no-ILD (Figure 1.1). RT-qPCR data showed that CD86 expression was elevated in the SSc-ILD group while no difference was observed in CD206 expression between the two groups (data not shown). The SSc-ILD group had higher proportions of double-positive (CD86+, CD206+) macrophages than SSc-no-ILD which, in contrast, had higher proportions of CD86+, CD206- macrophages (Figure 1.2). These results were supported by fluorescent microscopy images in which the SSc-ILD group had higher CD86 and CD206 expression than the SSc-no-ILD (Figure 1.3). Double staining clearly showed a more prevalent mixed activation of macrophages in the SSc-ILD group.

Conclusion

In this pilot study, recruitment and activation of mixed phenotype macrophages was more prominent in SSc-ILD than in SSc-no-ILD. Although levels of chemokines were not profoundly different between both groups, studying extensively the macrophage activation patterns in BAL provided novel findings regarding differences between the two groups. Since SSc is characterised by inflammatory and fibrotic phases, the mixed polarization of macrophages we showed for the first time in SSc-ILD patients on an organ level is a key aspect in such disease and could potentially serve as a target for therapeutics.

References

[1]Perelas A, Silver RM, Arrossi AV, Highland KB. Systemic sclerosis-associated interstitial lung disease. Lancet Respir Med. 2020;8(3):304-320. doi:10.1016/S2213-2600(19)30480-1

[2]Schmidt K, Martinez-Gamboa L, Meier S, et al. Bronchoalveoloar lavage fluid cytokines and chemokines as markers and predictors for the outcome of interstitial lung disease in systemic sclerosis patients. Arthritis Res Ther. 2009;11(4):R111. doi:10.1186/ar2766

Disclosure of Interests

Yehya Al-Adwi: None declared, Tji-Joong Gan: None declared, Janneke Bosma: None declared, Wayel Abdulahad: None declared, Isabella M. Atzeni: None declared, Marcel Van der Leij: None declared, Bart-Jan Kroesen: None declared, Alja J. Stel: None declared, Wim Timens: None declared, Janette Burgess: None declared, Harry van Goor: None declared, Johanna Westra: None declared, Douwe J Mulder Grant/research support from: Dr. DJ Mulder as an employee of the UMCG received research grants from Sanofi Genzyme which were paid to the UMCG

POS0581 HIGHER SKIN AUTOFLUORESCENCE IN INDIVIDUALS AT RISK FOR RHEUMATOID ARTHRITIS: RESULTS FROM A LARGE POPULATION BASED COHORT

Background

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease which is associated with increased mortality, mostly because of a higher incidence of cardiovascular disease (CVD), which cannot be explained by traditional risk factors alone. (1,2) Also studies showed that the cardiovascular events can already occur at a higher than expected rate shortly after the first symptoms of RA. (3)This raises the question if individuals with clinical suspect arthralgia (CSA) but not yet diagnosed with RA, already have an increased risk for developing cardiovascular disease compared to healthy controls and if this is also true for ACPA positive individuals without symptoms of clinical suspect arthralgia.

In our study we used skin autofluorescence (SAF), measured with the AGE reader, as an early non-invasive tool to identify subjects who are at increased risk for developing cardiovascular disease. (4) SAF measures the accumulation of AGEs in the skin and thereby offers a simple alternative to invasive measurement of AGE accumulation. (5)

Objectives

To investigate skin autofluorescence (SAF) levels, as an early indicator for cardiovascular disease, in relation to the presence of anticitrullinated protein antibodies (ACPA), clinical suspect arthralgia (CSA) and rheumatoid arthritis (RA) in a large population-based cohort.

Methods

Cross-sectional data were used from 17346 participants of the Dutch Lifelines Cohort Study, of whom baseline SAF and ACPA levels were available. The presence of CSA was determined using EULAR questions from the connective tissue disease screening questionnaire (CSQ). Individuals were divided into four groups: ACPA negative controls (n=17211), ACPA positive without CSA (n=49), ACPA positive with CSA (n=31) and defined RA (n=52). Multinomial regression was used to compare SAF levels and correct for potential confounders.

Results

SAF levels were higher in the ACPA positive with CSA group (OR 2.04, p=0.034) and the defined RA group (OR 3.10, p<0.001) compared to controls, but not in the ACPA positive without CSA group (OR 1.07, p=0.875). The difference in SAF levels remained statistically significant in the defined RA group after adjusting for age (OR 2.09, p=0.011), smoking status, renal function or HbA1c. In the ACPA positive with CSA group, the effect was found to be comparable (corrected for age: OR 2.09).

Conclusion

Our results indicate that ACPA positive individuals with CSA have elevated SAF levels, which is regarded as an early marker for oxidative stress and a possible indicator for development of cardiovascular disease. Therefore it is important to conduct further studies to explore if, in individuals with clinical suspect arthralgia, cardiovascular risk management should be considered in future clinical practice.

References

[1]Wolfe F, Mitchell DM, Sibley JT, Fries JF, Bloch DA, Williams CA, et al. The mortality of rheumatoid arthritis. Arthritis Rheum 1994 Apr;37(4):481-494.

[2]Symmons DP, Jones MA, Scott DL, Prior P. Longterm mortality outcome in patients with rheumatoid arthritis: early presenters continue to do well. J Rheumatol 1998 June 01;25(6):1072-1077.

[3]Kerola AM, Kauppi MJ, Kerola T, Nieminen TV. How early in the course of rheumatoid arthritis does the excess cardiovascular risk appear? Ann Rheum Dis 2012 October 01;71(10):1606-1615.

[4]Stirban A, Heinemann L. Skin Autofluorescence - A Non-invasive Measurement for Assessing Cardiovascular Risk and Risk of Diabetes. Eur Endocrinol 2014 August 01;10(2):106-110.

[5]Meerwaldt R, Graaff R, Oomen PHN, Links TP, Jager JJ, Alderson NL, et al. Simple non-invasive assessment of advanced glycation endproduct accumulation. Diabetologia 2004 July 01;47(7):1324-1330.

Figure 1.

The top chart shows SAF levels measured with the AGE reader in the 4 groups: ACPA negative controls, ACPA positive without CSA group, APCA positive with CSA group and defined RA group.

The lower picture shows the AGE reader we used from DiagnOptics Technologies BV, Groningen, the Netherlands: https://www.diagnoptics.com/

Acknowledgements

The Lifelines initiative has been made possible by subsidy from the Dutch Ministry of Health, Welfare and Sport, the Dutch Ministry of Economic Affairs, the University Medical Center Groningen (UMCG), Groningen University and the Provinces in the North of the Netherlands (Drenthe, Friesland, Groningen).

Disclosure of Interests

None declared.

Prognostic value of microvascular resistance and its association to fractional flow reserve: a DEFINE-FLOW substudy

Objective

This study aimed to evaluate the prognostic value of hyperemic microvascular resistance (HMR) and its relationship with hyperemic stenosis resistance (HSR) index and fractional flow reserve (FFR) in stable coronary artery disease.

Methods

This is a substudy of the DEFINE-FLOW cohort (NCT02328820), which evaluated the prognosis of lesions (n=456) after combined FFR and coronary flow reserve (CFR) assessment in a prospective, non-blinded, non-randomised, multicentre study in 12 centres in Europe and Japan. Participants (n=430) were evaluated by wire-based measurement of coronary pressure, flow and vascular resistance (ComboWire XT, Phillips Volcano, San Diego, California, USA).

Results

Mean FFR and CFR were 0.82±0.10 and 2.2±0.6, respectively. When divided according to FFR and CFR thresholds (above and below 0.80 and 2.0, respectively), HMR was highest in lesions with FFR>0.80 and CFR<2.0 (n=99) compared with lesions with FFR≤0.80 and CFR≥2.0 (n=68) (2.92±1.2 vs 1.91±0.64 mm Hg/cm/s, p<0.001). The FFR value was proportional to the ratio between HMR and the HMR+HSR (total resistance), 95% limits of agreement (−0.032; 0.019), bias (−0.003±0.02) and correlation (r²=0.98, p<0.0001). Cox regression model using HMR as continuous parameter for target vessel failure showed an HR of 1.51, 95% CI (0.9 to 2.4), p=0.10.

Conclusions

Increased HMR was not associated with a higher rate of adverse clinical events, in this population of mainly stable patients. FFR can be equally well expressed as HMR/HMR+HSR, thereby providing an alternative conceptual formulation linking epicardial severity with microvascular resistance.

Trial registration number

NCT02328820.

Reproducibility of quantitative flow ratio: the QREP study

BACKGROUND

Quantitative flow ratio (QFR) is a tool for physiological lesion assessment based on invasive coronary angiography.

AIMS

We aimed to assess the reproducibility of QFR computed from the same angiograms as assessed by multiple observers from different, international sites.

METHODS

We included 50 patients previously enrolled in dedicated QFR studies. QFR was computed twice, one month apart by five blinded observers. The main analysis was the coefficient of variation (CV) as a measure of intra- and inter-observer reproducibility. Key secondary analysis was the identification of clinical and procedural characteristics predicting reproducibility.

RESULTS

The intra-observer CV ranged from 2.3% (1.5-2.8) to 10.2% (6.6-12.0) among the observers. The inter-observer CV was 9.4% (8.0-10.5). The QFR observer, low angiographic quality, and low fractional flow reserve (FFR) were independent predictors of a large absolute difference between repeated QFR measurements defined as a difference larger than the median difference (>0.03).

CONCLUSIONS

The inter- and intra-observer reproducibility for QFR computed from the same angiograms ranged from high to poor among multiple observers from different sites with an average agreement of 0.01±0.08 for repeated measurements. The reproducibility was dependent on the observer, angiographic quality and the coronary artery stenosis severity as assessed by FFR.

Characterization of quantitative flow ratio and fractional flow reserve discordance using doppler flow and clinical follow-up

The physiological mechanisms of quantitative flow ratio and fractional flow reserve disagreement are not fully understood. We aimed to characterize the coronary flow and resistance profile of intermediate stenosed epicardial coronary arteries with concordant and discordant FFR and QFR. Post-hoc analysis of the DEFINE-FLOW study. Anatomical and Doppler-derived physiological parameters were compared for lesions with FFR+QFR- (n = 18) vs. FFR+QFR+ (n = 43) and for FFR-QFR+ (n = 34) vs. FFR-QFR- (n = 139). The association of QFR results with the two-year rate of target vessel failure was assessed in the proportion of vessels (n = 195) that did not undergo revascularization. Coronary flow reserve was higher [2.3 (IQR: 2.1-2.7) vs. 1.9 (IQR: 1.5-2.4)], hyperemic microvascular resistance lower [1.72 (IQR: 1.48-2.31) vs. 2.26 (IQR: 1.79-2.87)] and anatomical lesion severity less severe [% diameter stenosis 45.5 (IQR: 41.5-52.5) vs. 58.5 (IQR: 53.1-64.0)] for FFR+QFR- lesions compared with FFR+QFR+ lesions. In comparison of FFR-QFR+ vs. FFR-QFR- lesions, lesion severity was more severe [% diameter stenosis 55.2 (IQR: 51.7-61.3) vs. 43.4 (IQR: 35.0-50.6)] while coronary flow reserve [2.2 (IQR: 1.9-2.9) vs. 2.2 (IQR: 1.9-2.6)] and hyperemic microvascular resistance [2.34 (IQR: 1.85-2.81) vs. 2.57 (IQR: 2.01-3.22)] did not differ. The agreement and diagnostic performance of FFR using hyperemic stenosis resistance (> 0.80) as reference standard was higher compared with QFR and coronary flow reserve. Disagreement between FFR and QFR is partly explained by physiological and anatomical factors. Clinical Trials Registration https://www.clinicaltrials.gov ; Unique identifier: NCT01813435. Changes in central physiological and anatomical parameters according to FFR and QFR match/mismatch quadrants.

Diagnostic accuracy and reclassification potential of the acoustic CADScor algorithm in intermediate risk patients with suspected coronary artery disease

Background

Validation studies of the 2019 European Society of Cardiology pre-test probability model (ESC-PTP) for coronary artery disease (CAD) report that 35–40% of patients have intermediate pre-test risk (ESC-PTP 5-&lt;15%). A clear strategy for deferral or referral in this group has not been established. Stratification tools with a high negative predictive value (NPV) are especially wanted to improve pre-test risk estimates.

Acoustic detections of coronary stenosis are a new technology which could potentially be useful to supplement PTP stratification. One of the devices, the CADScor®System, has been shown to down-classify &gt;40% of patients to low risk without increasing CAD prevalence. However, the clinical utility of using the CADScor algorithm (version (V)3.1) has not be validated.

Purpose

1) To validate the diagnostic performance of the CADScor®System (V3.1), and 2) to study the reclassification potential of a clinical likelihood strategy by ESC-PTP estimation supplemented by a CAD-score.

Methods

In total, 1732 patients without known CAD but with symptoms suggestive hereof underwent coronary CTA as a first-line diagnostic test. Based on an interview prior to coronary CTA, the ESC-PTP model was applied and sound recordings were performed using the acoustic CADScor® System. Patients with a suspected &gt;50% diameter stenosis in any coronary segment at coronary CTA were referred to investigation with Invasive angiography (ICA) with measurement of Fractional flow reserve (FFR).

The ESC-PTP risk estimation was divided according to the recommended cut-offs of &lt;5%, 5-&lt;15% and &gt;15% PTP of obstructive CAD. Haemodynamically obstructive CAD was defined as: (1) FFR value &lt;0.80, (2) luminal diameter stenosis reduction &gt;90%, or (3) luminal diameter stenosis reduction ≥50% if FFR was indicated but not performed. A predefined cut-off value of 20 was used for CAD-score values to rule-out CAD.

Results

A suspected stenosis was found in 439 patients (26%) after coronary CTA. The follow up with ICA with FFR showed significant stenoses in 198 patients (12%).

In the entire cohort using the ≤20 CAD-score cutoff for CAD rule-out, sensitivity was 85.3% (95% CI 79.5–89.9%), specificity was 40.3% (95% CI 37.8–42.9%), the PPV was 5.9% (95% CI 13.8–18.3%)), and the NPV was 95.4% (95% CI 93.4–96.9%). Hence, the disease prevalence of obstructive CAD was 4.6% in the ruled-out patients.

Applying the ≤20 CAD-score cutoff for CAD rule-out in intermediate risk patients (ESC-PTP 5-&lt;15%) a total of 316 patients (48%) were down-classified to low risk with an obstructive CAD prevalence of 3.5%.

Conclusion

Having high NPV, the CADscor holds excellent rule-out power. Interestingly, the CADscor has reclassification properties in intermediate CAD risk patients where almost 50% can be deferred form further testing without increasing obstructive CAD risk. Thus, the CADscor can supplement clinical assessment to guide decisions on the need for further testing.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): The study was supported by the Health Research Fund of Central Denmark Region, Aarhus University Research foundation and by an institutional research grant from Acarix A/S, Denmark. Patient flowReclassification potential

One-step anatomic and function testing by cardiac CT versus second-line functional testing in symptomatic patients with coronary artery stenosis: head-to-head comparison of CT-derived fractional flow reserve and myocardial perfusion imaging

BACKGROUND

CT-QFR is a novel coronary computed tomography angiography (CTA)-based method for on-site evaluation of patients with suspected obstructive coronary artery disease (CAD).

AIMS

We aimed to compare the diagnostic performance of CT-QFR with myocardial perfusion scintigraphy (MPS) and cardiovascular magnetic resonance (CMR) as second-line tests in patients with suspected obstructive CAD after coronary CTA.

METHODS

A paired analysis of CT-QFR and MPS or CMR, with an invasive FFR-based classification as reference standard was carried out. Symptomatic patients with >50% diameter stenosis on coronary CTA were randomised to MPS or CMR and referred for invasive coronary angiography.

RESULTS

The rate of coronary CTA not feasible for CT-QFR analysis was 17%. Paired patient-level data were available for 118 patients in the MPS group and 113 in the CMR group. Patient-level diagnostic accuracy was better for CT-QFR than for both MPS (82.2% [95% CI: 75.2-89.2] vs 70.3% [95% CI: 62.0-78.7], p=0.029) and CMR (77.0% [95% CI: 69.1-84.9] vs 65.5% [95% CI: 56.6-74.4], p=0.047). Following a positive coronary CTA and with the intention to diagnose, CT-QFR, CMR and MPS were equally suitable as rule-in and rule-out modalities.

CONCLUSIONS

The diagnostic performance of CT-QFR as a second-line test was at least similar to MPS and CMR for the evaluation of obstructive CAD in symptomatic patients presenting with ≥50% diameter stenosis on coronary CTA.

Immediate post-procedural functional assessment of percutaneous coronary intervention: current evidence and future directions

Percutaneous coronary intervention (PCI) guided by coronary physiology provides symptomatic benefit and improves patient outcomes. Nevertheless, over one-fourth of patients still experience recurrent angina or major adverse cardiac events following the index procedure. Coronary angiography, the current workhorse for evaluating PCI efficacy, has limited ability to identify suboptimal PCI results. Accumulating evidence supports the usefulness of immediate post-procedural functional assessment. This review discusses the incidence and possible mechanisms behind a suboptimal physiology immediately after PCI. Furthermore, we summarize the current evidence base supporting the usefulness of immediate post-PCI functional assessment for evaluating PCI effectiveness, guiding PCI optimization, and predicting clinical outcomes. Multiple observational studies and post hoc analyses of datasets from randomized trials demonstrated that higher post-PCI functional results are associated with better clinical outcomes as well as a reduced rate of residual angina and repeat revascularization. As such, post-PCI functional assessment is anticipated to impact patient management, secondary prevention, and resource utilization. Pre-PCI physiological guidance has been shown to improve clinical outcomes and reduce health care costs. Whether similar benefits can be achieved using post-PCI physiological assessment requires evaluation in randomized clinical outcome trials.

OP0308 SENESCENT PROGENITOR CELLS IN THE SKIN OF LUPUS PATIENTS

Background:

Systemic lupus erythematosus (SLE) is an autoimmune disease, which is characterized by skin lesions, amongst other symptoms. These lesions (chronic discoid lupus erythematosus (CDLE) and subacute cutaneous lupus erythematosus (SCLE)) feature lymphocytic infiltration close to basal layer of the epidermis (i.e. the location of the epidermal progenitor cells), namely the epidermal dermal junction (EDJ) area. Epidermal progenitor cells maintain the homeostasis of the skin through their proliferation and differentiation into keratinocytes. In fast turnover tissues, like the skin, a population of ‘transient amplifying cells’ (TA cells), additionally facilitates generation of enough daughter cells to maintain skin homeostasis. These cells are located in an upper layer (suprabasal layer) of the epidermis, next to the basal layer. Senescence is an irreversible and locally spreading phenomenon that induces permanent cell cycle arrest.

Objectives:

To evaluate expression of senescence markers p16 and p21 in the epidermal progenitor and TA niches in patients with SCLE and CDLE. This was compared to a panel of other dermatological conditions with and without infiltration close to EDJ, as disease controls, and to control skin tissue.

Methods:

Age-matched skin lesions from patients with SCLE (n=12), CDLE (n=8), other conditions with EDJ infiltration (e.g. lichen planus, n=22), and dermatoses without EDJ infiltration (e.g. eczema, n=27), and non-lesion control biopsies (n=3) from SLE patients were employed. p16 and p21 expression in the progenitor niche (basal layer) and TA cell niche (suprabasal layer), and the whole epidermis of skin lesions biopsies were examined by immunohistochemistry.

Results:

In healthy skin biopsies, 0 ± 0 SEM p16+ cells/mm2 in the progenitor niche and 5 ± 4 SEM p21+ cells/mm2 in TA niche were observed. In skin lesions from patients with CDLE and SCLE, significantly more p16+ cells in the progenitor cell niche (45 ± 14 SEM/mm2) and p21+ cells (182 ± 38 SEM/mm2) in TA niches were detected, compared to control biopsies (p < 0.05), and compared to those dermatoses without EDJ infiltration (p16+ 11 ± 3 SEM/mm2, p21+ 86 ± 28 SEM/mm2, p < 0.05, Figure 1). p16 and p21 expression in CDLE and SCLE lesions did not significantly differ from other dermatoses with EDJ infiltration (p>0.05). Across all dermatoses analyzed, the number of p16+ cells was significantly correlated with the number of p21+ cells, both in the progenitor niche (r=0.45, p<0.0001) and TA niche (r=0.47, p<0.0001). p16+ cells however were more frequently found in the progenitor cell niche, and p21+ cells conversely in the TA cell niche (p<0.0001).

Figure 1.

Increased p16+ and p21+ cells in the progenitor and TA niches in dermatoses with EDJ infiltration. A. Graphic illustration for the progenitor cell niche (the basal layer), the transient amplifying (TA, the supra-basal layer) cell niche, and the further differentiated area. B-D. Representative staining of p16 (blue) and epidermal growth factor receptor (EGFR, brown, an epithelial cell marker) in dermatoses with (CDLE) and without (PMLE) epidermal-dermal junction (EDJ) infiltration groups. Black arrowheads point to p16+ progenitor epidermal cells. E-G. Representative staining of p21 (blue) and EGFR (brown) in dermatoses with (CDLE) and without (PMLE) EDJ infiltration groups. Hollow arrowheads point to p21+ TA epidermal cells. The dashed line indicates the EDJ. CDLE: chronic discoid lupus erythematosus, PMLE: polymorphous light eruption.

Conclusion:

In CDLE and SCLE, cutaneous manifestations of SLE, more progenitor and TA cells expressing markers of senescence were detected. This was in common with other dermatological conditions where lymphocytic infiltration is in close proximity to the progenitor and TA cell niche, namely in the EDJ. Increased senescence might infer the collapse of homeostasis in target (local) epidermis, which may influence tissue repair in the lesion. Elimination of senescent cells may therefore represent a viable therapeutic option to encourage timely and complete wound healing, in skin lesions of CDLE and SCLE patients.

Acknowledgements:

This research was funded by a China Scholarship Council grant (201606220074), Dutch Arthritis Foundation Translational Research Grant (T015-052) and a Dutch Arthritis Foundation Long Term Project Grant (LLP-29).

Disclosure of Interests:

None declared.

AB0082 PERSISTENT LOW COMPLEMENT LEVELS AND INTERFERON GENE UPREGULATION ARE PREDICTIVE FOR DISEASE PROGRESSION IN PATIENTS WITH INCOMPLETE SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

A subgroup of lupus patients present with mild symptoms and immunologic features, while they do not meet classification criteria for SLE. This disease state can be referred to as “incomplete systemic lupus erythematosus” (iSLE). Up to 55% of iSLE patients progress to SLE. Furthermore, previous research has shown that iSLE might overlap with early primary Sjögren’s disease (pSS).(1) Unfortunately, there are no predictive markers available for progression to classifiable disease. Type-I interferon (IFN) plays an important role in disease initiation of both SLE and pSS.(2,3) Myxovirus-resistance protein A (MxA) is a GTP-ase that has previously be demonstrated to correlate strongly with IFN-type I expression. Furthermore, interferon-inducible chemokines IFN-γ induced protein 10 (IP-10), and B-cell activating factor (BAFF), that are both inducible by IFN, are of interest, because it is demonstrated that these proteins are increased prior to the diagnosis of SLE.(4)

Objectives:

To find predictive markers that identify patients with incomplete systemic lupus erythematosus (iSLE) who are at the highest risk to progress to classifiable systemic lupus erythematosus (SLE) or primary Sjögren’s syndrome (pSS).

Methods:

Patients with iSLE (ANA ≥ 1:80, ≥ 1 clinical SLICC criterion, but not fulfilling the criteria, and disease manifestation <5 years) were included in a longitudinal observational study. Every half year, clinical status was evaluated and regular immunological serologic assessment was performed. Annually, interferon (IFN)-gene expression was determined by RT-PCR in whole blood using 14 genes. These genes represented 3 IFN-related modules. Some genes were mainly inducible by IFN-type I, others by IFN-type II. Furthermore, IFN-related mediators Myxovirus resistance protein A (MxA), interferon-gamma-induced protein 10 (IP-10) and B-cell activating factor (BAFF) were measured.

Results:

Of 38 included iSLE patients, 6 had developed SLE and 1 develop pSS (18%) after median follow up of 36 months. The 7 patients who developed SLE/pSS were all women, and were younger at baseline than those who remained having iSLE (median 26 years, IQR 20-29 vs. median 42 years, IQR 30-56, p=0.0009). Over time, these patients had significantly lower complement 3 (p<0.0001) and complement 4 levels (p=0.005), higher IFN-gene expression (p=0.007), and lower neutrophil counts (p=0.033) (see Figure 1.). No difference was found between IFN-type I and IFN-type II inducible genes. Levels of MxA, IP-10 and BAFF did not differ between patients who remained iSLE and who progressed to SLE/pSS.

Figure 1.

Conclusion:

Gender, age at diagnosis, persistent low complement levels, and high IFN-gene expression can help to identify iSLE patients at the highest risk of progressing to classifiable disease.

References:

[1]Md Yusof MY, et al. Prediction of autoimmune connective tissue disease in an at-risk cohort: Prognostic value of a novel two-score system for interferon status. Ann Rheum Dis. 2018;1–8.

[2]Yao Y, et al. Type I interferons in Sjögren’s syndrome. Autoimmun Rev. 2013;12(5):558–66.

[3]Crow MK. Type I Interferon in the Pathogenesis of Lupus. J Immunol [Internet]. 2014;192(12):5459–68.

[4]Lu R, et al. Dysregulation of innate and adaptive serum mediators precedes systemic lupus erythematosus classification and improves prognostic accuracy of autoantibodies. J Autoimmun. 2016;74:182–93.

Disclosure of Interests:

None declared

Polygenic Risk Score-Enhanced Risk Stratification of Coronary Artery Disease in Patients With Stable Chest Pain

BACKGROUND

Polygenic risk scores (PRSs) are associated with coronary artery disease (CAD), but the clinical potential of using PRSs at the single-patient level for risk stratification has yet to be established. We investigated whether adding a PRS to clinical risk factors (CRFs) improves risk stratification in patients referred to coronary computed tomography angiography on a suspicion of obstructive CAD.

METHODS

In this prespecified diagnostic substudy of the Dan-NICAD trial (Danish study of Non-Invasive testing in Coronary Artery Disease), we included 1617 consecutive patients with stable chest symptoms and no history of CAD referred for coronary computed tomography angiography. CRFs used for risk stratification were age, sex, symptoms, prior or active smoking, antihypertensive treatment, lipid-lowering treatment, and diabetes. In addition, patients were genotyped, and their PRSs were calculated. All patients underwent coronary computed tomography angiography. Patients with a suspected ≥50% stenosis also underwent invasive coronary angiography with fractional flow reserve. A combined end point of obstructive CAD was defined as a visual invasive coronary angiography stenosis >90%, fractional flow reserve <0.80, or a quantitative coronary analysis stenosis >50% if fractional flow reserve measurements were not feasible.

RESULTS

The PRS was associated with obstructive CAD independent of CRFs (adjusted odds ratio, 1.8 [95% CI, 1.5-2.2] per SD). The PRS had an area under the curve of 0.63 (0.59-0.68), which was similar to that for age and sex. Combining the PRS with CRFs led to a CRF+PRS model with area under the curve of 0.75 (0.71-0.79), which was 0.04 more than the CRF model (P=0.0029). By using pretest probability (pretest probability) cutoffs at 5% and 15%, a net reclassification improvement of 15.8% (P=3.1×10^-4) was obtained, with a down-classification of risk in 24% of patients (211 of 862) in whom the pretest probability was 5% to 15% based on CRFs alone.

CONCLUSIONS

Adding a PRS improved risk stratification of obstructive CAD beyond CRFs, suggesting a modest clinical potential of using PRSs to guide diagnostic testing in the contemporary clinical setting. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02264717.

Fractional flow reserve in clinical practice: from wire-based invasive measurement to image-based computation

Fractional flow reserve (FFR) and instantaneous wave-free ratio are the present standard diagnostic methods for invasive assessment of the functional significance of epicardial coronary stenosis. Despite the overall trend towards more physiology-guided revascularization, there remains a gap between guideline recommendations and the clinical adoption of functional evaluation of stenosis severity. A number of image-based approaches have been proposed to compute FFR without the use of pressure wire and induced hyperaemia. In order to better understand these emerging technologies, we sought to highlight the principles, diagnostic performance, clinical applications, practical aspects, and current challenges of computational physiology in the catheterization laboratory. Computational FFR has the potential to expand and facilitate the use of physiology for diagnosis, procedural guidance, and evaluation of therapies, with anticipated impact on resource utilization and patient outcomes.

Resting distal to aortic pressure ratio and fractional flow reserve discordance affects the diagnostic performance of quantitative flow ratio: Results from an individual patient data meta-analysis

OBJECTIVE

To evaluate the diagnostic performance of quantitative flow ratio (QFR) related to fractional flow reserve (FFR) and resting distal-to-aortic pressure ratio (resting Pd/Pa) concordance.

BACKGROUND

QFR is a method for computation of FFR based on standard coronary angiography. It is unclear how QFR is performed in patients with discordance between FFR and resting pressure ratios (distal-to-aortic pressure ratio [Pd/Pa]).

MATERIALS AND METHODS

The main comparison was the diagnostic performance of QFR with FFR as reference stratified by correspondence between FFR and resting Pd/Pa. Secondary outcome measures included distribution of clinical or procedural characteristics stratified by FFR and resting Pd/Pa correspondence.

RESULTS

Four prospective studies matched the inclusion criteria. Analysis was performed on patient level data reaching a total of 759 patients and 887 vessels with paired FFR, QFR, and resting Pd/Pa. Median FFR was 0.85 (IQR: 0.77-0.90). Diagnostic accuracy of QFR with FFR as reference was higher if FFR corresponded to resting Pd/Pa: accuracy 90% (95% CI: 88-92) versus 72% (95% CI: 64-80), p < .001, and sAUC 0.95 (95% CI: 0.92-0.96) versus 0.73 (95% CI: 0.69-0.77), p < .001. Resting Pd/Pa and FFR discordance were related to age, sex, hypertension, and lesion severity.

CONCLUSION

Diagnostic performance of QFR with FFR as reference is reduced for lesions with discordant FFR (≤0.80) and resting Pd/Pa (≤0.92) measurements.

Advanced heart sound analysis as a new prognostic marker in stable coronary artery disease

Aims

Recent technological advances enable diagnosing of obstructive coronary artery disease (CAD) from heart sound analysis with a high negative predictive value. However, the prognostic impact of this approach remains unknown. To investigate the prognostic value of heart sound analysis as two scores, the Acoustic-score and the CAD-score, in patients with suspected CAD which is treated according to standard of care.

Methods and results

Consecutive patients with angina symptoms referred for coronary computed tomography angiography (CTA) were enrolled. The Acoustic-score was developed from eight acoustic CAD-related features. This score was combined with risk factors to generate the CAD-score. A cut-off score >20 was pre-specified for both scores to indicate disease. If coronary CTA raised suspicion of obstructive CAD, patients were referred to invasive angiography and revascularized when indicated. Of 1675 enrolled patients, 1464 (87.4%) were included in this substudy. The combined primary endpoint was all-cause mortality and myocardial infarction (n = 26). Follow-up was 3.1 (2.7-3.4) years. Of patients with primary endpoints, the Acoustic-score was >20 in 25 (96%); the CAD-score was >20 in 22 (85%). In an unadjusted Cox analysis of the primary endpoints, the hazard ratio for scores >20 under current standard clinical care was 12.6 (1.7-93.2) for the Acoustic-score and 5.4 (1.9-15.7) for the CAD-score. The CAD-score contained prognostic information even after adjusting for lipid-lowering therapy initiation, stenosis at CTA, and early revascularization.

Conclusion

Heart sound analysis seems to carry prognostic information and may improve initial risk stratification of patients with suspected CAD.

Clinicaltrialsorg ID

NCT02264717.

Combining minimal risk stratification and prediction of obstructive CAD – clinical utility of a dual pre-test probability model

Background

The recently updated pre-test probability (PTP) model for diagnosing chronic coronary syndrome suggested by the European Society of Cardiology (ESC) was designed to predict the presence of obstructive coronary artery disease (CAD). In addition to this model, identification of non-obstructive CAD and utilization of preventive interventions may also lower rates of death and non-fatal myocardial infarction. Opposite to the ESC PTP, the minimal risk tool (MRT) is a new model developed to identify individuals without CAD but symptoms suggestive of CAD. We explored a combined use of the 2 models to predict the absence or presence of obstructive CAD.

Methods

This was a sub-study of the Danish study of Non-Invasive testing in Coronary Artery Disease (Dan-NICAD) which included patients with low-intermediate PTP of CAD. Minimal risk was defined as having a coronary calcium score of 0, no evidence of coronary atherosclerosis at coronary computed tomography angiography, and no cardiovascular (CV) events defined as myocardial infarction, death or revascularization in the mean observation period of 3.1 [2.7–3.4] years. Obstructive CAD was defined as a fractional flow reserve &lt;0.80 in a major vessel during invasive coronary angiography (ICA) or a high-grade stenosis by visual assessment (&gt;90% lumen reduction).

The risk factors included in the MRT were age, sex, smoking history, diabetes mellitus, dyslipidaemia, family history of premature CAD, hypertension, symptoms related to stress, and high-density lipoprotein concentration. Based on a point-system ranging from 0–5, the MRT and the ESC PTP were combined (dual-PTP) (figure 1). A dual-PTP ≤1 indicated very low risk. Using both minimal risk and obstructive CAD as references, the dual PTP was compared to the MRT and the ESC PTP through tests of model discrimination.

Results

Of the 1544 eligible patients, 710 (46%) had normal coronary arteries and no CV events. Obstructive CAD was diagnosed in 152 (10%).

Equivalent to a dual-PTP &lt;1 point, 209 patients with ESC PTP&lt;5% and MRT&gt;50% or ESC PTP 5–15% and MRT &gt;75% were classified as very low risk. Of these patients, 84% were at true minimal risk (red area figure 1). Furthermore, only 6 patients would have been diagnosed with obstructive CAD at ICA, and 0 events would be missed. The dual-PTP was non-inferior to the MRT and the ESC PTP in identifying patients having minimal risk and obstructive CAD, respectively (minimal risk: c-statistics 0.74 (0.72–0.77) vs. 0.76 (0.73–0.78); obstructive CAD: c-statistics 0.66 (0.62–0.70) vs. (0.67 (0.63–0.72)). The dual-PTP was superior to the ESC PTP in discriminating patients at minimal risk (c-statistics 0.74 (0.72–0.77) vs. 0.69 (0.67–0.71).

Conclusions

Combining the ESC PTP and the MRT, the dual-PTP seems to enable accurate prediction of both patients with minimal risk and patients with obstructive CAD. Based on the dual-PTP, patients can safely be deferred from or referred for diagnostic testing

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Aarhus University, Health Research Fund of Central Denmark Region

Low body weight and involuntary weight loss are associated with Raynaud's phenomenon in both men and women

Objectives: Low body weight is an easily assessable cause of Raynaud's phenomenon (RP), and is frequently overlooked by clinicians. We aim to investigate the association of low body weight (body mass index < 18.5 kg/m²), involuntary weight loss, and nutritional restrictions with the presence of RP.Method: Participants from the Lifelines Cohort completed a validated self-administered connective tissue disease questionnaire. Subjects who reported cold-sensitive fingers and biphasic or triphasic colour changes were considered to suffer from RP. Patient characteristics, anthropometric measurements, and nutritional habits were collected. Statistical analyses was stratified for gender.Results: Altogether, 93 935 participants completed the questionnaire. The prevalence of RP was 4.2% [95% confidence interval (CI) 4.1-4.4%], and was three-fold higher in women than in men (5.7% vs 2.1%, p < 0.001). Subjects with RP had a significantly lower daily caloric intake than those without RP. Multivariate analysis, correcting for creatinine level, daily caloric intake, and other known aetiological factors associated with RP, revealed that low body weight [men: odds ratio (OR) 5.55 (95% CI 2.82-10.93); women: 3.14 (2.40-4.10)] and involuntary weight loss [men: OR 1.32 (1.17-1.48); women: 1.31 (1.20-1.44)] were significantly associated with the presence of RP. Low-fat diet was also associated with RP in women [OR 1.27 (1.15-1.44)].Conclusion: Low body weight and prior involuntary weight loss are associated with an increased risk of RP in both men and women. This study emphasizes that low body weight and weight loss are easily overlooked risk factors for RP, and should be assessed and monitored in subjects with RP.

Overview of Quantitative Flow Ratio and Optical Flow Ratio in the Assessment of Intermediate Coronary Lesions

Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) improves clinical outcome compared with angiography-guided PCI. Advances in computational technology have resulted in the development of solutions, enabling fast derivation of FFR from imaging data in the catheterization laboratory. The quantitative flow ratio is currently the most validated approach to derive FFR from invasive coronary angiography, while the optical flow ratio allows faster and more automation in FFR computation from intracoronary optical coherence tomography. The use of quantitative flow ratio and optical flow ratio has the potential for swift and safe identification of lesions that require revascularization, optimization of PCI, evaluation of plaque features, and virtual planning of PCI.

Associations between clinical features and therapy with macrophage subpopulations and T cells in inflammatory lesions in the aorta from patients with Takayasu arteritis

Takayasu arteritis (TAK) is a large-vessel granulomatous vasculitis; the inflammatory infiltration in arteries comprises macrophages, multi-nucleated giant cells, CD4⁺ and CD8⁺ T cells, γδ T cells, natural killer (NK) cells and neutrophils. However, it is unknown which subtype of macrophages predominates. This study aims to evaluate macrophages subpopulations in the aorta in TAK. Immunohistochemistry was performed in the aorta from TAK patients (n = 22), patients with atherosclerotic disease (n = 9) and heart transplant donors (n = 8) using the markers CD68, CD86, CD206, CD3, CD20 and CD56. Active disease was observed in 54·5% of patients and active histological lesions were found in 40·9%. TAK patients presented atherosclerotic lesions in 27·3% of cases. The frequency of macrophages, M1 macrophages, T, B and NK cells was higher in the aorta from TAK and atherosclerotic patients compared to heart transplant donors. In TAK, macrophages and T cells were the most abundant cells in the aorta, and the expression of CD206 was higher than CD86 (P = 0·0007). No associations were found between the expression of cell markers and active disease or with atherosclerotic lesions. In TAK patients, histological disease activity led to higher T cell counts than chronic fibrotic lesions (P = 0.030), whereas prednisone use was associated with lower T cell counts (P = 0·035). In conclusion, M1 macrophages were more frequent in TAK and atherosclerotic patients compared to heart transplant donors, while M2 macrophages dominated M1 macrophages in TAK. T cells were associated with histological disease activity and with prednisone use in TAK.

SAT0285 VISUALISATION OF THE ACTIVE CALCIFICATION PROCESS WITH 18-F SODIUM FLUORIDE PET/CT IN LIMITED CUTANEOUS SYSTEMIC SCLEROSIS WITH CALCINOSIS CUTIS IS FEASIBLE: A PILOT STUDY

Background:

Calcinosis cutis is a major daily challenge to patients with longstanding systemic sclerosis (SSc), negatively affecting their quality of life. Unfortunately, treatment options are very limited due to lack of understanding of the pathogenetic process. Currently, calcinosis cutis is only detected at its irreversible end-stage. Early detection of calcinosis cutis could putatively allow early disease-modifying interventions and monitor treatment effects.

Objectives:

The aim of the current study is to assess the feasibility of visualising “active” micro-calcifications with 18-F Sodium Fluoride (NaF) PET scanning, compared to low-dose CT in patients with clinically overt calcinosis cutis.

Methods:

This was a cross-sectional, observational, pilot study. All patients met 2013 ACR/EULAR criteria for SSc. Patients underwent a whole body NaF PET/low-dose CT scan, scanned 90 minutes post-injection. (Sub)cutaneous calcifications were described and assessed on NaF PET, which was compared to CT images by two independent investigators.

Results:

A total of 10 female patients with limited cutaneous SSc [median age 56 years (IQR 52-66), median disease duration 17 years (8-19), PAH 10%, ILD 20%] were included, and compared to 10 controls [70 years (65-73)]. NaF uptake showed normal distribution throughout the skeletal bones, arterial tree, and visceral organs, which was comparable between patients and controls. Additionally, NaF uptake was visible in the skin of all SSc patients, but in none of the controls. Cutaneous NaF uptake largely correlated with clinical calcifications. Most common sites of cutaneous NaF uptake were fingers (6 patients) and knees (7 patients). Only 5% of the NaF positive lesions were not accompanied by visible calcifications on CT. Furthermore, of all calcified lesions seen on CT, 51% showed uptake on NaF PET. Small lesions (<1 cm), were generally only visible on CT, due to lower resolution of NaF PET.

Conclusion:

Imaging of “active” calcinosis cutis in limited cutaneous systemic sclerosis is feasible using NaF PET scanning. Most clinically overt calcifications and half of those seen on CT were positive for NaF uptake. Whether these “active” calcifications behave differently in terms of faster progression, clinical complaints, and infection risk, and whether these are potentially suitable for disease modifying interventions is subject to future study.

Disclosure of Interests:

None declared

Accuracy of 3-dimensional and 2-dimensional quantitative coronary angiography for predicting physiological significance of coronary stenosis: a FAVOR II substudy

Background

Three-dimensional quantitative coronary angiography (3D-QCA) enables reconstruction of a coronary artery in 3D from two angiographic image projections. This study compared the diagnostic accuracy of 3D-QCA vs. 2-dimensional (2D) QCA in predicting physiologically significant coronary stenosis, using fractional flow reserve (FFR) as the reference standard.

Methods

All interrogated vessels in the FAVOR II China study and the FAVOR II Europe-Japan study were assessed by 2D-QCA and 3D-QCA according to standard operating procedures in core laboratories. QCA analysts were blinded to the corresponding FFR values.

Results

A total of 645 vessels from 576 patients with 3D-QCA, 2D-QCA, and FFR were analyzed. Using the conventional cut-off value of 50% for percent diameter stenosis (DS%), 3D-QCA was more accurate in predicting FFR ≤0.80 than 2D-QCA [accuracy 74.0% (95% CI: 69.9-77.7%) vs. 64.9% (95% CI: 61.3-68.7%), difference: 9.1%, P<0.001]. Sensitivity was higher by 3D-QCA compared with 2D-QCA [69.1% (95% CI: 63.0-75.1%) vs. 47.1% (95% CI: 40.5-53.6%), difference: 22.0%, P<0.001] and specificity was similar [76.5% (95% CI: 72.5-80.6%) vs. 74.4% (95% CI: 70.2-78.6%), difference: 2.1%, P=0.40]. Area under the receiver operating characteristic curve was significantly higher for 3D-QCA than for 2D-QCA [0.81 (95% CI: 0.77-0.84) vs. 0.66 (95% CI: 0.62-0.71), P<0.001].

Conclusions

3D-QCA demonstrated better diagnostic performance in predicting physiologically significant coronary stenosis compared with 2D-QCA, when FFR was used as the reference standard.

Danish study of Non-Invasive testing in Coronary Artery Disease 2 (Dan-NICAD 2): Study design for a controlled study of diagnostic accuracy

BACKGROUND

Coronary computed tomography angiography (CTA) is the preferred primary diagnostic modality when examining patients with low to intermediate pre-test probability of coronary artery disease (CAD). Only 20-30% of these have potentially obstructive CAD. Because of the relatively poor positive predictive value of coronary CTA, unnecessary invasive coronary angiographies (ICAs) are conducted with the costs and risks associated with the procedure. Hence, an optimized diagnostic CAD algorithm may reduce the numbers of ICAs not followed by revascularization. The Dan-NICAD 2 study has 3 equivalent main aims: (1) To examine the diagnostic precision of a sound-based diagnostic algorithm, The CADScor®System (Acarix A/S, Denmark), in patients with a low to intermediate pre-test risk of CAD referred to a primary examination by coronary CTA. We hypothesize that the CADScor®System provides better stratification prior to coronary CTA than clinical risk stratification scores alone. (2) To compare the diagnostic accuracy of 3T cardiac magnetic resonance imaging (3T CMRI), ⁸²rubidium positron emission tomography (⁸²Rb-PET), and CT-derived fractional flow reserve (FFR_CT) in patients where obstructive CAD cannot be ruled out by coronary CTA using ICA fractional flow reserve (FFR) as reference standard. (3) To compare the diagnostic performance of quantitative flow ratio (QFR) and ICA-FFR in patients with low to intermediate pre-test probability of CAD using ⁸²Rb-PET as reference standard.

METHODS

Dan-NICAD 2 is a prospective, multicenter, cross-sectional study including approximately 2,000 patients with low to intermediate pre-test probability of CAD and without previous history of CAD. Patients are referred to coronary CTA because of symptoms suggestive of CAD, as evaluated by a cardiologist. Patient interviews, sound recordings, and blood samples are obtained in connection with the coronary CTA. If coronary CTA does not rule out obstructive CAD, patients will be examined by 3T CMRI ⁸²Rb-PET, FFR_CT, ICA, and FFR. Reference standard is ICA-FFR. Obstructive CAD is defined as an FFR ≤0.80 or as high-grade stenosis (>90% diameter stenosis) by visual assessment. Diagnostic performance will be evaluated as sensitivity, specificity, predictive values, likelihood ratios, calibration, and discrimination. Enrolment started January 2018 and is expected to be completed by June 2020. Patients are followed for 10 years after inclusion.

DISCUSSION

The results of the Dan-NICAD 2 study are expected to contribute to the improvement of diagnostic strategies for patients suspected of CAD in 3 different steps: risk stratification prior to coronary CTA, diagnostic strategy after coronary CTA, and invasive wireless QFR analysis as an alternative to ICA-FFR.

Prediction of Coronary Revascularization in Stable Angina: Comparison of FFRCT With CMR Stress Perfusion Imaging

OBJECTIVES

This study was designed to compare head-to-head fractional flow reserve (FFR) derived from coronary computed tomography angiography (CTA) (FFR_CT) and cardiac magnetic resonance (CMR) stress perfusion imaging for prediction of standard-of-care-guided coronary revascularization in patients with stable chest pain and obstructive coronary artery disease by coronary CTA.

BACKGROUND

FFR_CT is a novel modality for noninvasive functional testing. The clinical utility of FFR_CT compared to CMR stress perfusion imaging in symptomatic patients with coronary artery disease is unknown.

METHODS

Prospective study of patients (n = 110) with stable angina pectoris and 1 or more coronary stenosis ≥50% by coronary CTA. All patients underwent invasive coronary angiography. Revascularization was FFR-guided in stenoses ranging from 30% to 90%. FFR_CT ≤0.80 in 1 or more coronary artery or a reversible perfusion defect (≥2 segments) by CMR categorized patients with ischemia. FFR_CT and CMR were analyzed by core laboratories blinded for patient management.

RESULTS

A total of 38 patients (35%) underwent revascularization. Per-patient diagnostic performance for identifying standard-of-care-guided revascularization, (95% confidence interval) yielded a sensitivity of 97% (86% to 100%) for FFR_CT versus 47% (31% to 64%) for CMR, p < 0.001; corresponding specificity was 42% (30% to 54%) versus 88% (78% to 94%), p < 0.001; negative predictive value of 97% (91% to 100%) versus 76% (67% to 85%), p < 0.05; positive predictive value of 47% (36% to 58%) versus 67% (49% to 84%), p < 0.05; and accuracy of 61% (51% to 70%) versus 74% (64% to 82%), p > 0.05, respectively.

CONCLUSIONS

In patients with stable chest pain referred to invasive coronary angiography based on coronary CTA, FFR_CT and CMR yielded similar overall diagnostic accuracy. Sensitivity for prediction of revascularization was highest for FFR_CT, whereas specificity was highest for CMR.

Quantitative Flow Ratio Identifies Nonculprit Coronary Lesions Requiring Revascularization in Patients With ST-Segment-Elevation Myocardial Infarction and Multivessel Disease

BACKGROUND

The nonculprit lesion (NCL) management in ST-segment-elevation myocardial infarction patients with multivessel disease is debated. We sought to assess whether quantitative flow ratio (QFR), a noninvasive tool to identify potentially flow-limiting lesions, may be reliable in this scenario.

METHODS AND RESULTS

The present proof-of-concept study is based on a 3-step process: (1) identification of the QFR reproducibility in NCLs assessment (cohort A, n=31); (2) prospective validation of QFR diagnostic accuracy in respect to fractional flow reserve (cohort B, n=45); and (3) investigation of long-term clinical outcomes of NCLs stratified according to QFR (cohort C, n=110). A blinded core laboratory computed QFR values for all NCLs. Cohort A showed a good correlation and agreement between QFR values at index (acute) and at staged (subacute, 3-4 days later) procedures (r=0.98; 95% confidence interval, 0.96-0.99; mean difference, 0.004 [-0.027 to 0.34]). The inter-rater agreement was κ=0.9. In cohort B, fractional flow reserve and QFR identified 16 (33%) and 17 (35%) NCLs potentially flow limiting. Sensitivity, specificity, negative, and positive predictive values were 88%, 97%, 94%, and 94%. The area under the receiver operating characteristics curve was 0.96 (95% confidence interval, 0.89-0.99). Finally, in cohort C, we identified 110 ST-segment-elevation myocardial infarction patients where at least 1 NCL was left untreated. Patients with NCLs showing a QFR value ≤0.80 were at higher risk of adverse events (hazard ratio, 2.3; 95% confidence interval, 1.2-4.5; P=0.01).

CONCLUSIONS

In a limited and selected study population, our study showed that QFR computation may be a safe and reliable tool to guide coronary revascularization of NCLs in ST-segment-elevation myocardial infarction patients.

Coronary artery disease risk reclassification by a new acoustic-based score

To determine the potential of a non-invasive acoustic device (CADScor®System) to reclassify patients with intermediate pre-test probability (PTP) and clinically suspected stable coronary artery disease (CAD) into a low probability group thereby ruling out significant CAD. Audio recordings and clinical data from three studies were collected in a single database. In all studies, patients with a coronary CT angiography indicating CAD were referred to coronary angiography. Audio recordings of heart sounds were processed to construct a CAD-score. PTP was calculated using the updated Diamond-Forrester score and patients were classified according to the current ESC guidelines for stable CAD: low < 15%, intermediate 15–85% and high > 85% PTP. Intermediate PTP patients were re-classified to low probability if the CAD-score was ≤ 20. Of 2245 patients, 212 (9.4%) had significant CAD confirmed by coronary angiography ( ≥ 50% diameter stenosis). The average CAD-score was higher in patients with significant CAD (38.4 ± 13.9) compared to the remaining patients (25.1 ± 13.8; p < 0.001). The reclassification increased the proportion of low PTP patients from 13.6% to 41.8%, reducing the proportion of intermediate PTP patients from 83.4% to 55.2%. Before reclassification 7 (3.1%) low PTP patients had CAD, whereas post-reclassification this number increased to 28 (4.0%) (p = 0.52). The net reclassification index was 0.209. Utilization of a low-cost acoustic device in patients with intermediate PTP could potentially reduce the number of patients referred for further testing, without a significant increase in the false negative rate, and thus improve the cost-effectiveness for patients with suspected stable CAD.

Influence of Cardiac CT based disease severity and clinical symptoms on the diagnostic performance of myocardial perfusion

We aimed to identify factors influencing the sensitivity of perfusion imaging after an initial positive coronary computed tomography angiography (CCTA) using invasive coronary angiography (ICA) with conditional fractional flow reserve (FFR) as reference. Secondly we aimed to identify factors associated with revascularisation and to evaluate treatment outcome after ICA. We analysed 292 consecutive patients with suspected significant coronary artery disease (CAD) at CCTA, who underwent perfusion imaging with either cardiac magnetic resonance (CMR) or myocardial perfusion scintigraphy (MPS) followed by ICA with conditional FFR. Stratified analysis and uni- and multiple logistic regression analyses were performed to identify predictors of diagnostic agreement between perfusion scans and ICA and predictors of revascularisation. Myocardial ischemia evaluated with perfusion scans was present in 65/292 (22%) while 117/292 (40%) had obstructive CAD evaluated by ICA. Revascularisation rate was 90/292 (31%). The overall sensitivity for perfusion scans was 39% (30-48), specificity 89% (83-93), PPV 69% (57-80) and NPV 68% (62-74). Stratified analysis showed higher sensitivities in patients with multi-vessel disease at CCTA 49% (37-60) and typical chest pain 50% (37-60). Predictors of revascularisation were multi-vessel disease by CCTA (OR 3.51 [1.91-6.48]) and a positive perfusion scan (OR 4.69 [2.49-8.83]). The sensitivity for perfusion scans after CCTA was highest in patients with typical angina and multiple lesions at CCTA and predicted diagnostic agreement between perfusion scans and ICA. Abnormal perfusion and multi vessel disease at CCTA predicted revascularisation.

Pre-test probability prediction in patients with a low to intermediate probability of coronary artery disease: a prospective study with a fractional flow reserve endpoint

Aims

European and North American guidelines currently recommend pre-test probability (PTP) stratification based on simple probability models in patients with suspected coronary artery disease (CAD). However, no unequivocal recommendation has yet been established. We aimed to compare the ability of risk factors and different PTP stratification models to predict haemodynamically obstructive CAD with fractional flow reserve (FFR) as reference in low to intermediate probability patients.

Methods and results

We prospectively included 1675 patients with low to intermediate risk who had been referred to coronary computed tomography angiography (CTA). Patients with coronary stenosis were subsequently investigated by invasive coronary angiography (ICA) with FFR measurement if indicated. Discrimination and calibration were assessed for four models: the updated Diamond–Forrester (UDF), the CAD Consortium Basic, the Clinical, and the Clinical + Coronary artery calcium score (CACS). At coronary CTA, 24% of patients were diagnosed with a suspected stenosis and 10% had haemodynamically obstructive CAD at the ICA. Calibration for all CAD Consortium models increased compared with the UDF score. However, all models overestimated the probability of haemodynamically obstructive CAD. Discrimination increased by area under the receiver operating curve from 67% to 86% for UDF vs. CAD Consortium Clinical + CACS. The proportion of low-probability patients (pre-test score < 15%) was for the UDF, CAD Consortium Basic, Clinical, and Clinical + CACS: 14%, 58%, 51%, and 66%, respectively. The corresponding negative predictive values were 97%, 94%, 95%, and 98%, respectively.

Conclusion

CAD Consortium models improve PTP stratification compared with the UDF score, mainly due to superior calibration in low to intermediate probability patients. Adding the coronary calcium score to the models substantially increases discrimination.

Clinical Trials. gov identifier

NCT02264717.