Cardiac biomarkers as indicators of right ventricular dysfunction and recovery in chronic thromboembolic pulmonary hypertension patients after balloon pulmonary angioplasty therapy - a cardiac magnetic resonance imaging cohort study

Background

In chronic thromboembolic pulmonary hypertension, right heart failure determines outcome. Balloon pulmonary angioplasty therapy allows right heart recovery, which can be monitored by cardiac magnetic resonance imaging. This study evaluates whether cardiac biomarkers (NT-proBNP, MR-proANP, sST2, and PAPP-A) are associated with cardiac magnetic resonance imaging findings prior to and after balloon pulmonary angioplasty therapy.

Methods

This observational cohort study enrolled 22 chronic thromboembolic pulmonary hypertension patients who underwent balloon pulmonary angioplasty therapy and completed a six-month follow-up including cardiac magnetic resonance imaging. Biomarker levels were compared with findings for right heart morphology and function derived from cardiac magnetic resonance imaging.

Results

Pulmonary hemodynamics improved after balloon pulmonary angioplasty therapy [pulmonary vascular resistance: 7.7 (6.0–9.0) vs. 4.7 (3.5–5.5) wood units, p < 0.001; mean pulmonary artery pressure 41 (38–47) vs. 32 (28–37) mmHg, p < 0.001]. Cardiac magnetic resonance imaging findings indicated right heart maladaptation at baseline and recovery after therapy [right ventricular end-diastolic volume 192 (141–229) ml vs. 143 (128–172) ml, p = 0.002; right ventricular end-systolic volume 131 (73–157) ml vs. 77 (61–99) ml (p < 0.001); right ventricular ejection fraction (RVEF) 34 (28–41) % vs. 52 (41–54) %; p < 0.001]. Biomarker level cut-offs [NT-proBNP 347 ng/L (area under the curve (AUC) 0.91), MR-proANP 230 pg/L (AUC 0.78), PAPP-A 14.5 mU/L (AUC 0.81), and sST2 48.0 ng/ml (AUC 0.88)] indicated a RVEF ≤ 35% at baseline. The dynamics of NT-proBNP (rs = −0.79; p < 0.001), MR-proANP (rs = –0.80; p < 0.001), and sST2 (rs = –0.49; p = 0.02) correlated inversely with the improvement in RVEF after therapy. A relative decrease of NT-proBNP < 53% (AUC 0.86) and MR-proANP < 24% (AUC 0.82) indicated a limited RVEF response.

Conclusions

In chronic thromboembolic pulmonary hypertension patients, cardiac magnetic resonance imaging findings illustrate right heart failure and recovery after balloon pulmonary angioplasty therapy. Cardiac biomarker levels correlate with right heart parameters at baseline and their dynamics after therapy.

Predicting mortality in cardiovascular patients using electrocardiogram data and artificial intelligence

Background/Introduction

The electrocardiogram (ECG) is an ubiquitously used non-invasive tool for diagnosis and risk prediction in cardiology, granting deep extensive insights into the heart. Artificial intelligence (AI) is a modern resource allowing the processing of vast complex datasets in a way that is comparable to humans. Risk stratification in cardiovascular patients is mainly based on scoring systems, such as the ESC-SCORE, relying on traditional risk variables like cholesterol levels or arterial hypertension, rather than actual cardiac structure and function. Goal of this project was to predict mortality using AI in patients with cardiovascular risk based on the current cardiac situation represented by a standard 12-lead ECG recording.

Methods

The study population is based on an ongoing registry that started in 2010 and enrolled patients scheduled for an invasive coronary angiography due to suspected chronic coronary syndrome. Data of the following study patients were analysed: enrolment within the first two study years with available long-term follow-up data on the outcome measure overall mortality, availability of an ECG at admission without pacemaker stimulation and availability of all variables needed to calculate the ESC-SCORE (in the version weighed for a German population) as comparison. This led to a cohort of 720 patients, of whom 70 died within the follow-up period. Information on presence of a relevant coronary artery disease (CAD) was available for all patients, to differentiate between primary and secondary prevention. A deep learning architecture that was previously developed to detect myocardial scar in raw ECG time-series data was used. This model was trained with 1400 ECG recordings, from the publicly available PTB-XL dataset with 700 of those ECGs labelled for acute, recent or old myocardial infarction while 700 were labelled as healthy. This pre-trained model was then applied to our study cohort to predict long-term mortality based on a single 12-lead ECG obtained at admission.

Results

For mortality prediction in patients without CAD (primary prevention) the AI model compares to the ESC-SCORE with an AUROC of 0.606 vs 0.584. For CAD patients (secondary prevention) the AI model compares with an AUROC of 0.612 vs 0.658. Detailed results are presented in Table 1.

Conclusion(s)

Our data underlines the potential of an AI based approach, predicting mortality in cardiovascular patients using only single 12-lead ECG recordings. Additionally, our model achieved similar predictive information to established risk classification systems, such as the ESC-SCORE. Since data acquisition is still ongoing, we will continue to improve our model. In future work training AI to specifically predict mortality while also exploring explainable AI could lead to breakthrough findings in ECG interpretation.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): FlexiFunds by Forschungscampus Mittelhessen

Mid-regional pro-atrial natriuretic peptide and copeptin as indicators of disease severity and therapy response in CTEPH

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) leads to right heart failure. Pulmonary endarterectomy (PEA) or balloon pulmonary angioplasty (BPA) restore pulmonary haemodynamics and allow cardiac recovery. This study examined the relationship of copeptin and mid-regional pro-atrial natriuretic peptide (MR-proANP) levels to disease severity and therapy response.

METHODS

This observational cohort study included 125 patients (55 PEA/70 BPA) who underwent treatment and completed a 6-/12-month follow-up. Biomarkers, measured at baseline, prior to every BPA and at follow-up, were compared to 1) severe disease at baseline (right atrial pressure (RAP) ≥8 mmHg and cardiac index ≤2.4 L·min-1·m-2) and 2) optimal therapy response (no persistent pulmonary hypertension combined with a normalised RAP (mean PAP ≤25 mmHg, pulmonary vascular resistance (PVR) ≤3 WU and RAP ≤6 mmHg) or a reduction in mean PAP ≥25%, PVR ≥35% and RAP ≥25%).

RESULTS

Severely diseased patients had higher levels of MR-proANP (320 (246-527) pmol·L-1 versus 133 (82-215) pmol·L-1; p=0.001) and copeptin (12.7 (7.3-20.6) pmol·L-1 versus 6.8 (4.4-12.8) pmol·L-1; p=0.015) at baseline than the rest of the cohort. At baseline, MR-proANP (area under the curve (AUC) 0.91; cut-off value 227 pmol·L-1; OR 56, 95% CI 6.9-454.3) and copeptin (AUC 0.70; cut-off value 10.9 pmol·L-1; OR 1.5, 95% CI 1.2-1.9) identified severely diseased patients. After PEA/BPA, levels of MR-proANP (99 (58-145) pmol·L-1; p<0.001) and copeptin (6.3 (3.7-12.6) pmol·L-1; p=0.009) decreased and indicated optimal therapy response (MR-proANP <123 pmol·L-1 (AUC 0.70) and copeptin <10.1 pmol·L-1 (AUC 0.58)).

CONCLUSION

MR-proANP and copeptin levels are affected in CTEPH and decrease after therapy. MR-proANP identifies a severe disease status and optimal therapy response.

Galectin-3, GDF-15, and sST2 for the assessment of disease severity and therapy response in patients suffering from inoperable chronic thromboembolic pulmonary hypertension

PURPOSE

This study examined sST2, GDF-15, and galectin-3 as indicators of disease severity and therapy response in chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS

This study included 57 inoperable CTEPH patients who underwent balloon pulmonary angioplasty and 25 controls without cardiovascular disease. Biomarker levels were examined in relation to advanced hemodynamic impairment [tertile with worst right atrial pressure (RAP) and cardiac index], hemodynamic therapy response [normalized hemodynamics (meanPAP ≤25 mmHg, PVR ≤3 WU and RAP ≤6 mmHg) or a reduction of meanPAP ≥25%; PVR ≥ 35%, RAP ≥25%].

RESULTS

GDF-15 [820 (556-1315) pg/ml vs. 370 (314-516) pg/ml; p < 0.001] and sST2 [53.7 (45.3-74.1) ng/ml vs. 48.7 (35.5-57.0) ng/ml; p = 0.02] were higher in CTEPH patients than in controls. At baseline, a GDF-15 level ≥1443 pg/ml (AUC 0.88; OR 31.4) and a sST2 level ≥65 ng/ml (AUC 0.80; OR 10.9) were associated with advanced hemodynamic impairment. At follow-up GDF-15 ≤ 958 pg/ml (AUC = 0.74, OR 18) identified patients with optimal hemodynamic therapy response and ≤760 pg/ml (AUC = 0.79, OR 14).

CONCLUSION

GDF-15 and sST2 levels are higher in CTEPH and identified patients with advanced hemodynamic impairment. Further, decreased GDF-15 levels at follow-up were associated with hemodynamic therapy response. The diagnostic strength was not superior to NT-proBNP.

P5478Information on weather conditions improves the prognostic ability of 25 OH-vitamin D in stable coronary artery disease

Introduction and aim

Vitamin D deficiency is associated with an adverse prognosis in patients with coronary artery disease (CAD). Decreased levels of vitamin D are associated with low sunshine exposure, resulting in seasonal variations of vitamin D. The aims of this study were to investigate the influence of different specific weather conditions on vitamin D levels and to explore a possible improvement of risk stratification by vitamin D levels in stable patients with CAD using meteorological data.

Methods

The study population consists of two independent cohorts of stable patients undergoing coronary angiography with suspected or known CAD: as derivation cohort, the ongoing biomarker registry BioPROSPECTIVE with n=1,766 enrolled patients between 2010 and 2013 (median age 70.1 yrs; 30.8% females); and as validation cohort, the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study with n=3,299 patients (median age 63.5 yrs; 30.3% females). In the derivation cohort 235 (13.3%) patients were known to be deceased by 08/2018. In the validation cohort 760 (23.0%) patients died within a median follow-up time of 7.75 years. 25-OH vitamin D levels were measured by commercial assays. Vitamin D deficiency was defined as 25-OH vitamin D levels ≤20 ng/mL. Daily averaged data on six weather conditions of the 180 days prior to enrolment were collected for each patient from the weather station located closest to the respective study centre. Using air pressure, precipitation height, sunshine duration, temperature, relative humidity, and vapour pressure a weather model was constructed that significantly correlated with vitamin D levels (r=0.37; p<0.001).

Results

In the derivation cohort, median vitamin D levels were lower in non-survivors (13.3 [9.65–19.65] ng/mL) than in survivors (15.70 [10.7–22.65] ng/mL; p<0.001). Vitamin D predicted all-cause mortality with an area under the receiver operator characteristic curve (AUROC) of 0.576 (CI: 0.54–0.62). Adding the weather model to vitamin D significantly improved the AUROC to 0.601 (CI: 0.56–0.64; p=0.031). The vitamin D/weather model combination enhanced the prognostic value of the ESC SCORE to predict mortality (AUROC=0.571 [CI: 0.53–0.61] vs. 0.628 [CI: 0.59–0.67]; p=0.004). Comparable results were observed in the validation cohort. Here, vitamin D deficiency predicted mortality with a hazard ratio (HR) of 1.89 (CI: 1.59–2.26) after adjustment for ESC SCORE. Adding the weather model improved this HR to 1.92 (1.62–2.32). Reclassification analyses support the additive prognostic information of weather conditions with a continuous net reclassification improvement of 0.114 ([0.033–0.194]; p=0.006) if adding the weather model to vitamin D as base model for predicting mortality.

Conclusions

Different weather conditions show a significant impact on vitamin D levels in stable patients. Adding data on weather conditions improve the risk stratification by vitamin D for predicting mortality in stable CAD patients.

Acknowledgement/Funding

The study is financially supported by the Kerckhoff Heart Research Institute (KHFI) and the German Center for Cardiovascular Research (DZHK).

P6433Use of high-sensitivity cardiac troponin I (hs-cTnI) for secondary prevention in high-risk patients suffering from stable coronary artery disease

Background

There are several tools for primary prevention (e.g. Framingham, ESC) that can be used to predict mortality risk in healthy individuals. However, only a few scores have been validated to predict outcome in patients with cardiovascular disease. One of these instruments is the REACH (REduction of Atherothrombosis for Continued Health) score. The ESC guideline for stable coronary artery disease (CAD) places a clear emphasis on carrying out risk stratification before using invasive treatment. Recent studies have revealed a prognostic value of serum hs-cTnI in patients with stable CAD.

Purpose

The aim of this study was to evaluate the prognostic information provided by hs-cTnI in stable high-risk CAD patients.

Methods

Between 2011 and 2014, consecutive stable patients with suspected CAD undergoing coronary angiography were included in the study. Data from a 4-year follow-up was obtained; the study endpoint was defined as all-cause mortality. Serum hs-cTnI was measured before angiography using a high-sensitivity assay.

Results

A total of 3,742 patients were included, of whom 2,274 (60.1%) had confirmed CAD. Patients with an estimated annual mortality rate above 3% using the REACH score were defined as having high risk (n=996 in the low-risk group, n=1,278 in the high-risk cohort). Patients with higher risk were more often male (81.5% vs. 69.2%, p<0.001), were older (mean age 73.2±8.1 y vs. 63±9.4 y), and had more cardiovascular risk factors (diabetes mellitus (DM) 43.5% vs. 13.7%, p<0.001; arterial hypertension 90.8% vs. 86%, p<0.001). Median hs-cTnI was elevated in high-risk patients (6.9 ng/L [IQR 1–3: 3.8–14.8 ng/L] vs. 3 ng/L [IQR 1–3: 1.7–5.9 ng/L]; p<0.001). A total of 298 patients (23.3%) died in the high-risk group compared with 74 patients (7.4%) in the low-risk group. Log(hs-cTnI) was found to be a risk factor based on regression analysis including age, gender, DM, arterial hypertension and the REACH score (OR 2.02 [95% CI 1.61–2.54]). The area under the ROC of hs-cTnI for predicting all-cause mortality was 0.69 (95% CI 0.66–0.72) for hs-cTnI and 0.72 (95% CI 0.69–0.72) for the REACH score. There was a correlation between hs-cTnI and the REACH score (Spearman correlation 0.458; p<0.001). In patients at low risk, the best cut-off for hs-cTnI was 3 ng/L, and for high-risk patients 8.25 ng/L was the best threshold value. Using low REACH score and low hs-cTnI levels, it was possible to identify patients at very low risk with a mortality rate below 3.4% in a follow-up of 48 months. It was also feasible to determine patients at very high risk in the group of patients who were already at high risk using the hs-cTnI cut-off (mortality 15.2% vs. 33.7%).

Conclusion

Hs-cTnI was found to be an independent risk factor in low- as well as high-risk patients. Hs-cTnI levels correlate with the REACH risk score. Moreover, it was possible to separate patients at very high and very low risk by combining REACH score and hs-cTnI.

P1730Serial high-sensitivity troponin I measurements to discriminate type 2 from type 1 myocardial infarction

Background

Acute myocardial infarction (MI) is associated with high morbidity and mortality. A robust differentiation between type 1 and type 2 MI (T1/T2MI) has prognostic and therapeutic implications. We investigated whether serial high-sensitivity cardiac troponin I measurements could reliably discriminate T1MI from T2MI in patients presenting with a non-ST elevation myocardial infarction (NSTEMI).

Methods

We used data from a prospective acute coronary syndrome biomarker registry of patients with suspected MI that presented at or were transferred to one of two study centres. Here, we analysed an unselected group of 265 NSTEMI patients (67.2% males). Blood was drawn on admission and after 3 hours. High-sensitivity troponin I (hs-cTnI) was measured in frozen samples by a technician blinded to patient characteristics. T1MI or T2MI was defined as the gold-standard study diagnosis by two independent cardiologists based on all available data according to the Third Universal Definition of MI.

Results

A diagnosis of T2MI was made in 55 patients (20.8%) in the NSTEMI cohort. T2MI patients did not differ from T1MI patients regarding age, gender, traditional risk factors, or percentage of those with a history of coronary artery disease. Median baseline hs-cTnI levels were higher in T1MI (436.25; IQR 63.7–1918.8 ng/L) than in T2MI patients (48.4; IQR 11.7–305.9 ng/L; p<0.001). Absolute change in hs-cTnI concentration between 0 and 3 h was greater in T1MI than in T2MI patients with Dhs-cTnI 93.6 ng/L (IQR 13.5–815.3 ng/L) vs. 20.4 ng/L (IQR 2.5–106.5 ng/L) (p<0.001). hs-cTnI yielded an area under the receiver operator characteristics (AUROC) curve for identifying T2MI at baseline of 0.71 (IQR 0.64–0.79) and after 3 h of 0.7 (IQR 0.61–0.78).Dhs-cTnI was associated with an AUROC of 0.68 (IQR 0.6–0.76). Regarding a rule-out approach, Youden-optimized cut-offs for hs-cTnI at baseline as well as for the absolute change in hs-cTnI concentration were calculated (186.5 ng/L; 154.4 ng/L). Use of these two criteria yielded a sensitivity of 89% (78–96%) and a negative predictive value of 95% (89–98%) to exclude T2MI. 49 of 55 T2MI patients would have been ruled out using this algorithm.

Conclusion

Our data show that hs-cTnI concentrations differ between patients presenting with T1 and T2MI. The concentration of hs-cTnI and its change over time has the potential to rule out T2MI and therefore to identify patients who might benefit from an early invasive management. The differentiation between T1MI and T2MI by using hs-cTnI is nevertheless challenging, and further research on specific algorithms is needed.

Acknowledgement/Funding

3German Center for Cardiovascular Research (DZHK), Partnersite Rhein Main, Bad Nauheim, Germany

P2774Galectin-3, GDF-15, and ST2 in noninvasive assessment of myocardial remodelling in chronic thromboembolic pulmonary hypertension

Background

In chronic thromboembolic pulmonary hypertension (CTEPH), pulmonary artery obstruction leads to impaired pulmonary hemodynamics and secondary right heart failure, which is highly predictive of outcome. Thus, the extent of myocardial -especially right heart- remodelling is an indicator of disease severity.

Purpose

The aim of the present study was to assess growth differentiation factor-15 (GDF-15), galectin-3, and suppression of tumorigenicity 2 (ST2) as non-invasive biomarkers of myocardial remodelling in patients suffering from CTEPH.

Methods

We analysed the serum levels of GDF-15, galectin-3 and ST2 in a cohort of 64 CTEPH patients and in a control group of 25 patients without cardiovascular disease. The biomarker levels were further correlated with clinical, laboratory, and hemodynamic data, including 6-minute walking distance (6-MWD), N-terminal pro-brain natriuretic peptide (NT-proBNP), mean pulmonary artery pressure (meanPAP), pulmonary vascular resistance (PVR), and right atrial pressure (RAP).

Results

The biomarker levels in the control group were: galectin-3: 3.5 ng/l (IQR 2.7–4.0), GDF-15: 92.6 pg/ml (IQR 78.5–129.1), and ST2: 48.65 ng/l (IQR 35.5–57.0). CTEPH patients had higher levels of GDF-15 (196.7 pg/ml; IQR 128.4–302.8; p<0.001) and ST2 (52.6 ng/l; IQR 44.5–71.9; p=0.05) but not galectin-3 (3.4 ng/l; IQR 2.7–4.3; p=0.84). In the CTEPH cohort, patients with a meanPAP >35 mmHg (GDF-15: p=0.01; ST2: p=0.04) and patients with a PVR >500 dyn sec cm–5 (GDF-15: p=0.004; ST2: p=0.002) had significantly increased biomarker levels. For the detection of a meanPAP >35mmHg, ROC analysis revealed an AUC of 0.71 for GDF-15 and 0.67 for ST2. The level of GDF-15 correlated with the level of NT-proBNP (rrs=0.69; p≤0.001) and the RAP (rrs=0.54; p≤0.001) and inversely with the 6-MWD (rrs=−0.47; p≤0.001). The level of ST2 correlated with the level of NT-proBNP (rrs=0.67; p≤0.001) and the RAP (rrs=0.54; p≤0.001) and inversely with the 6-MWD (rrs=-0.31; p=0.02).

Conclusion

Our results demonstrate that GDF-15 and ST2, non-invasive biomarkers of myocardial remodelling, are significantly elevated in patients suffering from CTEPH. The correlation of biomarker levels with established outcome predictors suggests a use as indicators of disease severity.

Early changes in N-terminal pro-B-type natriuretic peptide levels after transcatheter aortic valve replacement and its impact on long-term mortality

BACKGROUND

N-terminal pro-hormone B-type natriuretic peptide (NT-proBNP) levels correlate with higher peri-procedural mortality after transcatheter aortic valve replacement (TAVR). The long-term prognostic value of NT-proBNP within the first days after TAVR, however, remains unclear. This study examined early changes in NT-proBNP prior to and within 6 days after TAVR, the diagnostic value of this biomarker regarding aortic regurgitation (AR), and its prognostic value regarding one-year mortality.

METHODS AND RESULTS

NT-proBNP concentrations were measured in 504 consecutive patients undergoing transapical (TA) or transfemoral (TF) TAVR before and directly after TAVR as well as 4 h and 1, 2, 3, and 6 days after TAVR. The follow-up period was 1 year. NT-proBNP was elevated in all patients at baseline (median 2141 ng/L [IQR 1021-5319 ng/L]). NT-proBNP changes in the first 6 days after TAVR showed significant differences depending on the approach, with a greater and more prolonged rise evident in TA-TAVR patients. NT-proBNP was an independent predictor of mortality in TA patients with AR, with an AUC of 0.794 (95% CI 0.663-0.925; P = 0.003) when measured on day 3 after TAVR. For TF patients with AR and reduced left ventricular systolic function, the AUC for prediction of mortality was 0.897 (95% CI 0.778-1.0; P = 0.004) on day 2.

CONCLUSIONS

The prognostic information of early post-procedural NT-proBNP concentrations is superior to pre-procedural values regarding all-cause mortality within 1 year. Post-procedural NT-proBNP must be interpreted in relation to the TAVR approach. NT-proBNP predicts mortality in TF-TAVR patients with AR and reduced left ventricular function.