Calcium scoring on coronary computed angiography tomography with photon-counting detector technology: Predictors of performance

INTRODUCTION

Obtaining accurate coronary artery calcium (CAC) score measurements from CCTA datasets with virtual non-iodine (VNI) algorithms would reduce acquisition time and radiation dose. We aimed to assess the agreement of VNI-derived and conventional true non-contrast (TNC)-based CAC scores and to identify the predictors of accuracy.

METHODS

CCTA datasets were acquired with either 120 or 140 ​kVp. CAC scores and volumes were calculated from TNC and VNI images in 197 consecutive patients undergoing CCTA. CAC density score, mean volume/lesion, aortic Hounsfield units and standard deviations were then measured. Finally, percentage deviation (VNI - TNC/TNC∗100) of CTA-derived CAC scores from non-enhanced scans was calculated for each patient. Predictors (including anthropometric and acquisition parameters, as well as CAC characteristics) of the degree of discrepancy were evaluated using linear regression analysis.

RESULTS

While the agreement between TNC and VNI was substantial (mean bias, 6.6; limits of agreement, 178.5/145.3), a non-negligible proportion of patients (36/197, 18.3%) were falsely reclassified as CAC score ​= ​0 on VNI. The use of higher tube voltage significantly decreased the percentage deviation relative to TNC-based values (β ​= ​-0.21 [95%CI: 0.38 to -0.03], p ​= ​0.020) and a higher CAC density score also proved to be an independent predictor of a smaller difference (β ​= ​-0.22 [95%CI: 0.37 to -0.07], p ​= ​0.006).

CONCLUSION

The performance of VNI-based calcium scoring may be improved by increased tube voltage protocols, while the accuracy may be compromised for calcified lesions of lower density. The implementation of VNI in clinical routine, however, needs to be preceded by a solution for detecting smaller lesions as well.

18F-sodium fluoride positron emission tomography and coronary plaque radiomics derived from computed tomography angiography for prediction of myocardial infarction

Background

Assessments of coronary disease activity with 18F-sodium fluoride positron emission tomography (18F-NaF PET) and radiomics-based precision coronary plaque phenotyping derived from contrast-enhanced computed tomography (CT) have both been shown to enhance risk stratification in patients with coronary artery disease (CAD). To date, no study has investigated whether these two promising methods (which can be obtained during a single imaging session on a hybrid PET/CT scanner) are interchangeable or can provide superior predictive performance when used in combination.

Purpose

We sought to investigate whether the prognostic information provided by latent morphological radiomic coronary plaque features and assessments of disease activity by 18F-NaF PET are complementary in prediction of myocardial infarction.

Methods

Patients with known CAD underwent coronary 18F-NaF PET and CT angiography on a hybrid PET/CT scanner. Coronary 18F-NaF uptake was determined by the coronary microcalcification activity (CMA). We performed quantitative plaque analysis of coronary CT angiography datasets. Additionally, coronary plaque segmentations on CT angiography were used to extract 1103 radiomic features. Using weighted correlation network analysis we derived latent morphological features of coronary plaques which were aggregated to patient-level radiomic normograms to predict myocardial infarction using univariate and multivariate Cox proportional hazard models.

Results

The study cohort comprised of 260 patients with established CAD (age: 65±9 years; 84% men); 179 (69%) participants showed increased coronary 18F-NaF activity (CMA >0). Over 53 [40–59] months of follow-up 18 patients had a myocardial infarction. Using weighted correlation network analysis, from the 1103 radiomic features we derived 15 distinct eigen radiomic features representing latent morphological coronary plaque patterns. On univariate cox modelling 7 of these emerged as predictors of myocardial infarction (Figure). Following adjustments for calcified, noncalcified and low-density noncalcified plaque volumes and 18F-NaF CMA 4 radiomic features (related to texture and geometry) remained independent predictors of myocardial infarction (Figure).

Conclusion(s)

In patients with established CAD latent morphological features of coronary plaques are predictors of myocardial infarction above and beyond plaque volumes and 18F-NaF uptake. Comprehensive plaque analysis with radiomics may enhance risk stratification of CAD patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIH, Wellcome Trust

Identification of non-calcified coronary plaque characteristics using machine learning radiomic analysis of non-contrast high-resolution CT

Objective

To explore whether machine learning (ML) radiomic analysis of low-dose, high-resolution, non-contrast, ECG gated cardiac CT scan allows identification of non-calcified coronary plaque characteristics.

Background

Novel imaging and analysis techniques may provide the ability to detect non-calcified or high risk coronary plaques on a non-contrast CT scan, advancing cardiovascular diagnostics.

Methods

We prospectively enrolled 125 patients with a non-calcified plaque and an adverse plaque characteristic (APC), and 25 controls without visible atherosclerosis on coronary CT angiography (CCTA). All patients underwent the non-contrast CT exam prior to CCTA. 419 radiomic features were calculated to identify: presence of any CAD, obstructive CAD (stenosis>50%), plaque with ≥2 APC, degree of calcification and specific APCs. ML models were trained on a training set (917 segmentations) and tested on a separate (validation) set (292 segmentations).

Results

Among the radiomic features 88.3% was associated with any plaque, 0.9% with obstructive CAD and 76.4% with presence of at least two APCs. Overall, 80.2%, 88.5% and 36.5%, of features were associated with calcified, partially calcified, and noncalcified plaques, respectively. Regarding APCs, 61.1%, 61.8%, 84.2%, and 61.3%, of features were associated with low attenuation (LAP), napkin-ring sign (NRS), spotty calcification (SC), and positive remodeling (PR), respectively. ML models outperformed conventional methods for the presence of plaque, obstructive stenosis, presence of 2 APC, as well as for noncalcified plaque and partially calcified plaque, but not for calcified plaque. ML models also significantly outperformed identification of LAP and PR, but neither NRS nor SC.

Conclusions

Radiomic analysis of non-contrast CT heart exams may allow identification of specific non-calcified coronary plaque characteristics which could aid cardiovascular risk stratification or pre-screening of individuals prior to contrast enhanced CCTA exam.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Science Center

Hypoattenuated leaflet thickening is associated with silent brain injury

Background

The association between hypoattenuated leaflet thickening (HALT) following transcatheter aortic valve implantation (TAVI) and stroke remains contradictory. Whether HALT carries an increased risk of subclinical brain injury (SBI) has not been investigated.

Purpose

We investigated whether HALT is associated with SBI on MRI. Furthermore, we assessed whether post-TAVR SBI impacts the patients' cognition and outcome.

Methods

153 patients undergoing TAVR were prospectively enrolled. Brain MRI was performed shortly post-TAVR and 6 months (6M) later to assess the occurrence of acute silent cerebral ischaemic lesions (SCIL) and chronic white matter hyperintensities (WMH). HALT was screened by cardiac CT angiography 6M post-TAVR. Neurocognitive evaluation was performed before, shortly after and 6M following TAVR.

Results

At 6M, 115 patients had diagnostic CTA and 10 had HALT. HALT status, baseline and follow-up MRIs were available in 91 cases. At 6M, new SCIL was evident in 16%, new WMH in 66%. New WMH was more frequent (100% vs 62%; p=0.047) with higher median volume (319 vs 50 mm3; p=0.039) among HALT-patients. In uni- and multivariate analysis, HALT was associated with new WMH volume (beta: 0.72; 95% CI: 0.2–1.39; p=0.009).

The patients' cognitive trajectory from pre-TAVR to 6M showed significant association with the 6M SCIL volume (beta: −4.69; 95% CI: −9.13 to −027; p=0.038), but was not related to the presence or volume of new WMH. During a 3.1-year follow-up neither HALT, nor the related WMH burden was related with increased mortality (HALT HR: 0.86, 95% CI: 0,202–3,687; p=0.84; new WMH HR: 1.09; 95% CI: 0,701–1,680; p=0.71).

Conclusions

6M post-TAVR, HALT was linked with greater WMH burden, but did not carry an increased risk of cognitive decline or mortality over a 3.1-year follow-up.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): János Bolyai Scholarship of the Hungarian Academy of Sciences

A new perspective to evaluate CLOSE protocol by coronary CT angiography including the evaluation of left atrial wall thickness

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This study was supported by the National Research, Development and Innovation Office of Hungary (NKFIA; NVKP_16-1-2016-0017 National Heart Program). The research was supported by the Thematic Excellence Programme (Tématerületi Kiválósági Program, 2020-4.1.1.-TKP2020) of the Ministry for Innovation and Technology in Hungary, within the framework of the Therapeutic Development and Bioimaging programmes of the Semmelweis University. The project was supported by the KH-17 Programme of the National Research, Development and Innovation Office of the Ministry of Innovation and Technology in Hungary (NKFIH). Bálint Szilveszter MD PhD was supported by the ÚNKP-20-4-II New National Excellence Program of the Ministry for Innovation and Technology from the source of the National research, Development and Innovation fund. M. Boussoussou and B. Vattay were supported by the “NTP-NFTÖ” (Nemzeti Tehetség Program, Nemzet Fiatal Tehetségeiért Ösztöndíj) program of the Ministry of Human Capacities in Hungary (EMMI) and by the EFOP-3.6.3-VEKOP-16-2017-00009.

Introduction

The CLOSE protocol is a novel contact-force guided technique for enclosing pulmonary veins in patients with atrial fibrillation (AF). We sought to determine whether left atrial (LA) wall thickness (LAWT) and pulmonary vein (PV) dimensions as assessed by coronary CT angiography (CTA) could influence the efficacy of successful first-pass isolation using the CLOSE protocol. Methods: In a single center, prospective study we enrolled 94 patients with symptomatic, drug-refractory AF who underwent pre-ablation left atrial CTA and initial radiofrequency catheter ablation between 2019.01-2020.09. The LA was divided into 11 regions when assessing LAWT. Additionally, the diameter and area of the PV orifices were obtained. First pass isolation was recorded separately for the right and left PVs. After the first-pass ablation circles were ready, additional ablations were applied in those cases where first pass isolation was not achieved, to reach complete PV isolation. Predictors of successful first pass isolation were determined using logistic regression models that included anthropometrical, echocardiographic and CTA derived parameters. Results: A total of 94 patients were included in the analysis with mean CHA2DS2-VASc score of 2.1 ± 1.5 (mean age 62.4 ± 12.6 years, 39.5% female). 61.7 % were paroxysmal, 38.3 were persistent AF patients. First-pass isolation rate was 76%, 71% and 54%, for the right PVs, left PVs and all four PVs, respectively. No difference was found regarding comorbidities and imaging parameters between those with and without first-pass isolation. LAWT (mean of all 11 regions or separately) had no effect on the procedural outcome (all p >0.05). Mean procedure times were 81.2 ± 19.3 minutes. Complete isolation of all four PVs was achieved in 100% of patients. Out of all assessed parameters, only RSPV diameter was associated with right sided successful PVI on first pass isolation (p = 0.04, OR 1.01). Conclusion: The use of CLOSE protocol in AF patients resulted in high periprocedural success rate in terms of first pass isolation, independently from the thickness of the LA wall. RSPV diameter could influence the results of first pass isolation.

The impact of left atrial strain parameters on systolic and diastolic improvement following TAVI

Introduction

Transcatheter aortic valve implantation (TAVI) can improve left ventricular (LV) mechanics and has been shown to improve long term survival. Data on the prognostic value of left atrial (LA) strain following TAVI are scarce. LA strain – a surrogate of LV filling pressure - can aid the early detection of diastolic dysfunction and correlates with the extent of fibrosis in atrial remodelling.

Purpose

In this multimodality study, we aimed to evaluate the prognostic value of LA function measured before hospital discharge following TAVI and to further elucidate its association with LV and LA reverse remodelling.

Methods

In this prospective single center study, we investigated 90 patients (mean age 78.5 years, 46.7% female) with severe, symptomatic aortic stenosis (AS) who underwent transthoracic echocardiography immediately after TAVI and 6 months later. LA and LV global longitudinal strain parameters were obtained by speckle tracking echocardiography. CT angiography (CTA) was performed for pre-TAVI planning and repeated at 6 months follow-up. LV mass values were derived from the serial CTA images. We defined LV reverse remodelling as reduction of myocardial mass quantified on CTA and as an improvement of LV global longitudinal strain (GLS). LA reverse remodelling was assessed based on the peak reservoir strain values (LAGS). The association of LA and LV global strain parameters, LA stiffness, systolic and diastolic functional parameters and LV mass based reverse remodelling were analysed using Pearson correlation coefficient and linear regression models.

Results

The mean LAGS and LVGLS values were 17.7% and 15.3% at discharge and 20.2% and 16.6% at follow-up, respectively (p=0.024, p<0.001). LA and LV strain values improved in 60.6% and 74.5% of all patients. Reduced LAGS (<20%) was found in 66.7% of all patients at baseline. LA strain at discharge correlated significantly with diastolic parameters (E wave, E/e', LAVI, all p<0.05). Atrial reverse remodelling based on LAGS change correlated with LVGLS change (p<0.01, standardized β=0.53) and LAGS at discharge (p=0.012, standardized β=−0.30).

LAGS correlated with the extent of morphological LV remodelling based on LV mass reduction (p=0.002, coeff: 0.36). Elevated LA stiffness at discharge (upper tercile) leads to substantially lower LAGS at 6 months versus patients with lower LA stiffness value (1. and 2. tercile): 16.4±10.0 vs 21.9±9.8, p=0.042.

Conclusion

Patients with reduced LAGS immediately after TAVI showed a larger extent of LV reverse remodelling during follow up. On the other hand, increased LA stiffness at discharge was consistent with irreversible LA damage as demonstrated by a lack of improvement in LA function.

Funding Acknowledgement

Type of funding sources: None.

Association of daily coffee consumption with cardiovascular health – results from the UK Biobank

Background

There are conflicting reports on the association of coffee consumption with cardiovascular (CV) health. The UK Biobank is a prospective cohort study including data for half a million middle-aged individuals.

Purpose

We studied the association of daily coffee consumption with all-cause and CV mortality, and incidence of the major CV diseases in the UK Biobank. In a subgroup of participants who underwent cardiovascular magnetic resonance (CMR), we evaluated the association between regular coffee intake and cardiac structure and function parameters.

Methods

UK Biobank cohort of participants without clinically manifested heart disease at the time of recruitment were included. Regular coffee intake was categorized into 3 groups: zero, light-to-moderate (0.5–3 cups/day) and high (>3 cups/day) coffee drinkers. We estimated association of daily coffee consumption with incident outcomes using multivariable Cox-regression models (median follow-up of 11 years) and, in the subset with CMR data, with left and right ventricular (LV, RV) end-systolic and end-diastolic volumes, LV mass, and LV/RV stroke volume using multivariable linear regression. Models were adjusted for potential confounders and mediators, including: age, sex, non-European ethnicities, body mass index, smoking, physical activity, Townsend deprivation index, alcohol, meat, fruit and vegetable intake, hypertension, diabetes mellitus, and cholesterol level.

Results

We included 468,629 individuals (mean age 56.2±8.1 years, 44.2% male). Among them, 22.1% did not consume coffee on a regular basis, 58.4% had 0.5–3 cups per day and 19.5% had >3 cups per day. After adjustment for potential confounders and mediators, compared to non-coffee drinkers, light-to-moderate coffee drinking was associated with lower risk of all-cause mortality (HR=0.88, p<0.001), CV mortality (HR=0.83, p=0.006), and incident stroke (HR=0.79; p=0.037). CMR data were available in 30,650 participants. In multivariable analysis, compared to non-coffee drinkers, both the light-to-moderate and high coffee consuming categories, were associated with significantly increased LV and RV ventricular end-systolic (β=0.91 and 1.64 for LV and 1.10 and 1.72 for RV), end-diastolic (β=2.21 and 3.28 for LV and 2.24 and 3.35 for RV) and stroke volumes (β=1.31 and 1.64 for LV and 1.15 and 1.63 for RV), as well as greater LV mass (β=0.78 and 1.64; all p<0.001).

Conclusion

In this large study of the UK Biobank population, regular coffee consumption of up to 3 cups per day was associated with favorable cardiovascular outcomes, in particular, decreased all-cause and CV mortality and stroke incidence. Regular coffee consumption was also associated with a pattern of CMR metrics in keeping with the reverse of age-related cardiac alterations.

Funding Acknowledgement

Type of funding sources: None.

Left atrial appendage size is a marker of atrial fibrillation recurrence after radiofrequency catheter ablation in patients with persistent atrial fibrillation

Background

Catheter ablation is an established therapy for rhythm control in patients with drug-refractory atrial fibrillation (AF), however, recurrence is frequent particularly in persistent AF. There are no consistently confirmed predictors of AF recurrence after catheter ablation. The left atrial appendage (LAA) potentially plays an important role in AF recurrence, although the exact mechanism and pathophysiology are still unclear.

Purpose

We aimed to study whether LAA volume (LAAV) and function influence the long-term recurrence of AF after point-by-point radiofrequency catheter ablation, depending on AF type.

Methods

AF patients who underwent point-by-point radiofrequency catheter ablation after preprocedural cardiac computed tomography (CT) and transthoracic and transesophageal echocardiography (TEE) were included in this retrospective analysis. LAAV and LAA orifice area were measured by CT and LAA flow velocity assessed by TEE and was used as a surrogate marker of LAA function. Uni- and multivariable Cox proportional hazard regression models were performed to determine the predictors of AF recurrence.

Results

In total, 561 AF patients (61.9±10.2 years, 34.9% females) were included in the study. Recurrence of AF was detected in 40.8% of the cases (34.6% in patients with paroxysmal and 53.5% in those with persistent AF) with a median recurrence-free time of 22.7 [9.3–43.1] months. Patients with AF recurrence had significantly higher body surface area-indexed left atrial volume (iLAV), LAAV and LAA orifice area, as compared to those without recurrence. Moreover, patients with persistent AF had significantly higher iLAV, LAAV, LAA orifice area and lower LAA flow velocity, than those with paroxysmal AF. After adjustment for the main cardiovascular risk factors and comorbidities left ventricular ejection fraction (LVEF) <50% (HR=2.17; 95% CI=1.38–3.43; p<0.001) and LAAV (HR=1.06; 95% CI=1.01–1.12; p=0.029) were independently associated with AF recurrence in persistent AF, while no independent predictors could be identified in paroxysmal AF.

Conclusions

The current study demonstrates that beyond left ventricular systolic dysfunction, LAA enlargement is associated with higher rate of AF recurrence after catheter ablation in persistent AF, but not in patients with paroxysmal AF. Our results suggest that preprocedural assessment of LVEF and LAAV might contribute to optimal patient selection and aid to improve long-term results of ablation procedures in patients with persistent AF.

Funding Acknowledgement

Type of funding sources: None.

Adverse coronary plaque characteristics are more common in patients with diabetes

Introduction

Diabetes mellitus (DM) is associated with increased cardiovascular morbidity and mortality. However, there is a lack of data about the prevalence of adverse coronary artery plaques characteristics in patients with DM.

Purpose

In our study we aimed to compare the prevalence of adverse atherosclerotic coronary artery plaque characteristics between patients with and without DM.

Methods

We have analyzed the data of patients who underwent coronary computed tomography angiography (CCTA) between October 2012 and December 2020. Our exclusion criteria were coronary anomaly, congenital or other structural heart disease, previous revascularization or heart transplantation, non-diagnostic image quality and no available data on the presence of DM. Patients were divided into two groups based on the presence of DM.

Results

In total, 11,357 patients were included in our study. Prevalence of DM was 14.5%. There were significant differences in age (63.2±9.5 vs 58.1±12.2 years, p<0.001) and major cardiovascular risk factors such as hypertension, dyslipidemia and smoking between the two groups (all p<0.05). We have measured higher coronary artery calcium score in patients with DM vs. without DM (424.3±744.0 vs 174.2±794.6, p<0.001). Obstructive coronary artery disease (stenosis >70%) was more frequent in the DM group (24.6% vs 10.5%, p<0.001). While 29.6% of patients without DM had at least one plaque with adverse characteristics, this rate was 38.9% in those with DM (positive remodeling: 19.6% vs 26.1%, low attenuation: 7.6% vs 10.2%, spotty calcium: 16.9% vs 21.6%, napkin-ring sign: 1.7% vs 2.6%, all p<0.05).

Conclusions

The prevalence of severe coronary artery stenosis and coronary plaques with adverse characteristics was higher in patients with DM. Multivariate analysis is needed to further explore this association.

Funding Acknowledgement

Type of funding sources: None.

Rising utilization of coronary CT angiography across Europe over the last decade: insights from a large prospective European registry

Background/Introduction

The recently updated 2019 ESC guidelines for the diagnosis and management of chronic coronary syndromes endorse the use of coronary computed tomography angiography (CCTA) for exclusion of obstructive coronary artery disease in patients with a low clinical likelihood (Class I, LOE B). Higher demand for CCTA requires broad availability, inevitably involving smaller healthcare providers, such as non-academic hospitals and private practices. Nevertheless, most published data on CCTA image quality and safety rely on exams performed in high-volume academic centers, and little is known about CCTA in non-academic settings.

Purpose

To investigate the utilization of CCTA across Europe over the last decade, focusing on differences between academic and non-academic centers.

Methods

We included patients with stable chest pain and suspected coronary artery disease (CAD) who received CCTA and were included in the European Society of Cardiovascular Radiology MR/CT registry 01/2010–01/2020. We compared CT equipment, image quality, radiation dose, the incidence of periprocedural adverse events, patient characteristics, and CCTA findings between academic (high volume university hospitals) and non-academic centers (non-academic hospitals and private practices).

Results

Overall, 64,317 patients (41.2% women; age 60±13 years) from 212 sites across 19 European countries were included. Academic centers submitted most cases in 2010—2014 (51.6%), whereas non-academic centers accounted for 71.3% of records in 2015–2020. While non-academic centers used less advanced technology, radiation dose remained low (4.54 [interquartile range (IQR) 2.28–6.76] mSv) with a 30% decline of high-dose scans (>7 mSv) over time. Diagnostic image quality was reported in 97.7% of cases, and the rate of acute scan-related events was low (0.4%) (Figure 1). From 2010–2014 to 2015–2020, CCTA nearly doubled in patients with low to intermediate pretest-probability, women >50, and 40–60 years old men (Figure 2). CAD presence and extent decreased slightly over time (prevalence: 2010–2014: 41.5% vs. 2015–2020: 40.6%), (multi-vessel disease in those with CAD: 2010–2014: 61.9% vs. 2015–2020: 55.9%; all p<0.01).

Conclusion

CCTA expands rapidly to non-academic centers across Europe, increasing availability while maintaining relatively low radiation dose, high diagnostic image quality, and safety. Broad availability of high-quality CCTA is essential for a successfully implementation of the recently updated guidelines for the diagnosis and management of chronic coronary syndromes.

Funding Acknowledgement

Type of funding sources: None. Changes in CCTA utilizationChanges in patient characteristics

The role of left atrial wall thickness and pulmonary vein anatomy in success of pulmonary vein isolation using the CLOSE protocol

Introduction

The CLOSE protocol is a novel contact-force guided technique for enclosing pulmonary veins in patients with atrial fibrillation (AF). Consistency and lesion contiguity are essential factors for procedural success. We sought to determine whether left atrial (LA) wall thickness (LAWT) and pulmonary vein (PV) dimensions as assessed by coronary CT angiography (CTA) could influence the efficacy of successful first-pass isolation using the CLOSE protocol.

Methods

In a single center, prospective study we enrolled 94 patients with symptomatic, drug-refractory AF who underwent pre-ablation left atrial CTA and initial radiofrequency catheter ablation between 2019.01–2020.09. The LA was divided into 11 regions when assessing LAWT. Additionally, the diameter and area of the PV orifices were obtained. First pass isolation was recorded separately for the right and left PVs. After the first pass ablation circles were ready, additional ablations were applied in those cases where first pass isolation was not achieved, to reach complete PV isolation. Predictors of successful first pass isolation were determined using logistic regression models that included anthropometrical, echocardiographic and CTA derived parameters.

Results

A total of 94 patients were included in the analysis with mean CHA2DS2-VASc score of 2.1±1.5 (mean age 62.4±12.6 years, 39.5% female). 61.7% were paroxysmal, 38.3 were persistent AF patients. Mean procedure times were 81.2±19.3 minutes.

Complete isolation of all four PVs was achieved in 100% of patients. First-pass isolation rate was 76%, 71% and 54%, for the right PVs, left PVs and all four PVs, respectively. No difference was found regarding comorbidities and imaging parameters between those with and without first pass isolation. LAWT (mean of all 11 regions or separately) had no effect on the procedural outcome (all p>0.05). Out of all assessed parameters, only RSPV diameter was associated with right sided successful PVI on first pass isolation (p=0.04, OR 1.01).

Conclusion

The use of CLOSE protocol in AF patients resulted in high periprocedural success rate in terms of first pass isolation, independently from the thickness of the LA wall. RSPV diameter could influence the results of first pass isolation.

Funding Acknowledgement

Type of funding sources: None.

Orientation of the right superior pulmonary vein affects outcome after pulmonary vein isolation

Funding Acknowledgements

Type of funding sources: None.

Aims

Controversial results have been published regarding the influence of pulmonary vein (PV) anatomical variations on outcomes after pulmonary vein isolation (PVI). However, no data is available on the impact of PV orientation on the long-term success rates of point-by-point PVI. We sought to determine the impact of PV anatomy and orientation on atrial fibrillation (AF)-free survival in patients undergoing PVI using the radiofrequency point-by-point technique.

Methods and results

We retrospectively included 448 patients who underwent initial point-by-point radiofrequency ablation for AF at our department. Left atrial CT-angiography (CTA) was performed before each procedure. PV anatomical variations, ostial parameters (area, effective diameter and eccentricity), orientation and their associations with 24-month AF-free survival were analyzed. PV anatomical variations and ostial parameters were not predictive for AF-free survival (all p > 0.05). Univariate analysis showed that female sex (p = 0.025) was associated with higher rates of AF recurrence, ventral-caudal (p = 0.002), dorsal-cranial (p = 0.034) and dorsal-caudal (p = 0.042) orientation of the right superior PV (RSPV), on the other hand, showed an association with lower rates of AF recurrence, as compared to the reference ventral-cranial orientation. On multivariate analysis, both female sex [odds ratio(OR) 1.83, 95% CI 1.15-2.93, p = 0.011] and ventral-caudal RSPV orientation, compared with ventral-cranial orientation, proved to be independent predictors of 24-month AF recurrence (OR 0.37, 95% CI 0.19-0.71, p = 0.003).

Conclusion

  Female sex and ventral-caudal RSPV orientation have an impact on long-term arrhythmia-free survival. Assessment of PV orientation may be a useful tool in predicting AF-free survival and may contribute to a more personalized management of AF.

The association between early vascular aging and cyclothymic affective temperament

Funding Acknowledgements

Type of funding sources: None.

onbehalf

Cardiovascular Imaging Research Group

Background

Affective temperaments (depressive, anxious, irritable, hyperthymic, cyclothymic) are regarded as the biologically stable core of personality, and accumulating data implies their relationship with cardiovascular diseases. There are currently limited data on the association of affective temperaments and early vascular aging.

Purpose

The aim of our study was to assess the potential relationship of affective temperaments and vascular age, as assessed by coronary CT.

Methods

In our current cross-sectional study, 209 patients referred to coronary computed tomography angiography (CCTA) due to suspected coronary artery disease (CAD), were included. After the evaluation of medical history and demographic parameters, all patients completed the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire (TEMPS-A) and the Beck Depression Inventory (BDI). Vascular age was estimated using coronary artery calcium (CAC) score and we calculated its difference from chronological age for each patient. Linear regression analysis was applied to identify predictors of early vascular aging in the entire cohort and in male and female sub-populations, separately.

Results

The independent predictors of early vascular aging were female sex (B = -10.82 [95%CI: -15.30 – -6.33]), diabetes mellitus (B = 7.16 [95%CI: 1.20 – 13.12]) and dyslipidemia (B = -8.28 [95%CI: 3.94 – 12.62]). Further assessing gender differences, cyclothymic temperament score proved to be an independent predictor of early vascular aging in women (B = 0.89 [95%CI: 0.04 – 1.75]), while this association was absent in men.

Conclusion

Our results suggest that cyclothymic affective temperament contribute to early vascular aging in women.

Predictors of cerebral embolisation after percutaneous transfemoral aortic valve implantation (TAVI) in the RETORIC substudy

Purpose

To evaluate the predictors, occurrence and distribution of TAVI-related silent ischemic brain lesions using diffusion MRI.

Methods and materials

We investigated 109 consecutive patients with severe aortic stenosis from the prospective arm of the RETORIC study who underwent brain MRI one week afterpercutaneous transfemoral aortic valve implantation TAVI. To determine the occurrence and distribution of periprocedural cerebral ischemic lesions averaged diffusion-weighted images (trace) and mean diffusivity (MD) maps from the DTI dataset were used. To evaluate the aortic valve calcium score (AVCS), we assessed the preoperative prospectively ECG-triggered cardiac CT (256-slice MDCT). We also assessed the periprocedural factors such as periprocedural time, pre- and postdilatation. Multivariate linear regression analysis was performed to identify the independent predictors of TAVI-related ischemic lesions.

Results

After TAVI, a total of 918 new cerebral ischemic lesions were detected in 100/109 patients (92%). The median ischemic lesion volume was 237 μl (interquartile range 89.5–650) with a median lesion number of 6 (2–10) per patient. 759/918 lesions (83%) were supratentorial (389 left vs 370 right). Most lesions (628/918, 68%) were subcortical; the left and right MCA territories were the most affected (190. The vast majority of ischemic lesions were clinically silent (96%); 4% of patients had stroke which was proven by MRI. The median AVCS was 2769 (interquartile range 1858–4537). Balloon predilatation during TAVI procedure showed significant correlation with increased total ischemic lesion volume (p<0.001, β = 0.370) on univariate analysis, AVCS, periprocedural time, or postdilatation were not associated with ischemic load on MRI (p<0.05).

Conclusions

Periprocedural ischemic lesions are frequent (92%), most of them are clinically silent, however. Only balloon dilatation during TAVI was a predictor of increased ischemic load.

Aortic valve Ca scoring and DWI MRI

Funding Acknowledgement

Type of funding source: None

P3381Quantification of hypo-attenuated leaflet thickening after transcatheter aortic valve implantation - clinical relevance of HALT volume

Background

Hypo-attenuated leaflet thickening (HALT) is a recently recognized phenomenon following transcatheter aortic valve implantation (TAVI) and there is no consensus over the standardized assessment of HALT and its clinical relevance is poorly understood. We sought to determine the predictors and clinical significance of HALT volume.

Methods

Patients, who previously underwent TAVI between 2011 and 2016 were prospectively enrolled in the RETORIC (Rule out Transcatheter Aortic Valve Thrombosis with Post Implantation Computed Tomography) study, a single-center observational study. At inclusion cardiac computed tomography angiography (CTA), transthoracic echocardiography (TTE) and brain magnetic resonance imaging (MRI) was performed. HALT was volumetrically quantified on cardiac CTA images by segmenting the inner volume of the TAVI frame at the level of the leaflets and applying a threshold of −200 to 200 Hounsfield units. We evaluated the clinical predictors of HALT volume, and its association with ischemic brain MRI lesions (recent and chronic large vessel ischemic focuses, microbleed/microembolization, white matter or small vessel disease) and all-cause mortality.

Results

In total, we analyzed 111 patients with CoreValve bioprosthesis (56.7% female, mean age 80.3±7.4 years). A median of 19 [IQR: 11–29] months passed between TAVI procedure and enrollment. The mean HALT volume was 111.0±163.4 mm3. Current malignant disease, prosthesis implantation depth measured on CTA images acquired at inclusion, and aortic mean gradient and aortic valve area evaluated on TTE images at inclusion predicted HALT volume by univariate analysis (all p<0.05). After multivariate adjustment, aortic mean gradient remained a significant predictor of HALT volume (beta-coefficient: 11.5, 95% CI: 5.0–18.0; p<0.001). HALT volume was not associated with ischemic brain MRI lesions (all p>0.05) and did not predict all-cause mortality (median follow-up: 20 months [IQR: 18–23]; HR: 1.0; 95% CI: 1.0–1.0; p=0.15).

Volumetric quantification of HALT.

Conclusion

Aortic mean gradient was the only predictor independently associated with HALT volume. Our results suggest that TAVI valve function is negatively affected by HALT volume, however, we found no association of HALT volume with cerebrovascular ischemic lesions or increased risk for all-cause mortality.

P6183Diagnostic performance of coronary computed tomography angiography-derived fractional flow reserve in patients with acute myocardial infarction and moderate non-culprit coronary stenosis

Background

Revascularisation of significant non-culprit coronary lesions (NCL) may improve clinical outcome in patients with myocardial infarction and multi vessel disease, however management of moderate NCLs is still controversial. Dobutamine stress echocardiography (DSE) and invasive fractional flow reserve (FFR) are accepted methods to detect myocardial ischemia, nevertheless coronary CT angiography-derived fractional flow reserve (CT-FFR) is a new modality, which has not been widely investigated to date in patients with NCLs.

Purpose

Our aim was to determine the diagnostic performance of CT-FFR compared to DSE and invasive FFR.

Methods

In this prospective trial, DSE, FFR and CT-FFR were performed in every patient with MI and at least one moderate NCL (30–70% diameter stenosis by visual assessment). New or worsening wall motion abnormality in at least two contiguous myocardial segments on DSE, and FFR value<0.8 in invasive FFR and CT-FFR as well were determined as abnormal. In comparison, DSE and FFR were regarded as reference standard methods.

Results

Between March of 2017 and December of 2018, 51 patients (58.2±10.4 years, 74.5% male) were enrolled and 71 NCLs (40 LAD, 13 LCx, 18 RCA) were investigated. Dobutamine stress echocardiography, FFR and CT-FFR were positive in 30.9%, 32.3% and 22.5% of all lesions, respectively. FFR values were higher with CT-FFR compared to invasive FFR (0.85±0.11 vs. 0.83±0.08, p<0.05). Compared to DSE, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of CT-FFR were 40.9%, 85.7%, 56.2%, 76.3% and 71.8%, respectively. The same values were 39.1%, 85.4%, 56.2%, 74.5% and 70.4% compared to invasive FFR, respectively. Correspondence of CT-FFR with DSE (k=0.29) and with FFR (k=0.27) was weak.

Conclusion

This is the first study that compares the three modalities in the evaluation of moderate NCLs. Our results demonstrated moderate diagnostic accuracy, excellent specificity, poor sensitivity and PPV and acceptable NPV of CT-FFR compared to DSE and FFR. At this stage, CT-FFR is probably not accurate enough to determine revascularisation strategy of moderate NCLs as a single non-invasive method.

P6166Radiomics-based machine learning versus histogram analysis and visual assessment to identify advanced atherosclerotic lesions on coronary computed tomography angiography

Background

Currently used coronary CT angiography (CTA) plaque classification and histogram-based methods have limited accuracy to identify advanced atherosclerotic lesions. Radiomics-based machine learning (ML) could provide a more robust tool to identify high-risk plaques.

Purpose

Our objective was to compare the diagnostic performance of radiomics-based ML against histogram-based methods and visual assessment of ex-vivo coronary CTA cross-sections to identify advanced atherosclerotic lesions as defined by histology.

Methods

Overall, 21 coronaries of seven hearts were imaged ex vivo with coronary CTA. From 95 coronary plaques 611 histological cross-sections were obtained and classified based-on the modified American Heart Association scheme. Histology cross-sections were considered advanced atherosclerotic lesions if early, late fibroatheroma or thin-cap atheroma was present. Corresponding coronary CTA cross-section were co-registered and classified into homogenous, heterogeneous, napkin-ring sign plaques based on plaque attenuation pattern. Area of low attenuation (<30HU) and average CT number was quantified. In total, 1919 radiomic parameters describing the spatial complexity and heterogeneity of the lesions were calculated in each coronary CTA cross-section. Eight different radiomics-based ML models were trained on randomly selected cross-sections (training set: 75% of the cross-sections) to identify advanced atherosclerotic lesions. Plaque attenuation pattern, histogram-based methods and the best ML model were compared on the remaining 25% of the data (test-set) using area under the receiver operating characteristic curves (AUC) to identify advanced atherosclerotic lesions using histology as a reference.

Results

After excluding sections with heavy calcium (n=32) and no visible atherosclerotic plaque on CTA (n=134), we analyzed 445 cross-sections. Based on visual assessment, 46.5% of the cross-sections were homogeneous (207/445), 44.9% heterogeneous (200/445) and 8.6% were with napkin-ring sign (38/445). Radiomics-based ML model incorporating 13 parameters significantly outperformed visual assessment, area of low attenuation and average CT number to identify advanced lesions (AUC: 0.73 vs. 0.65 vs. 0.55 vs. 0.53; respectively; p<0.05 for all).

Conclusions

Radiomics-based ML analysis may be able to improve the discriminatory power of CTA to identify high-risk atherosclerotic lesions.