Risk factors based vessel-specific prediction for stages of coronary artery disease using Bayesian quantile regression machine learning method: Results from the PARADIGM registry.

BACKGROUND AND HYPOTHESIS: The recently introduced Bayesian quantile regression (BQR) machine-learning method enables comprehensive analyzing the relationship among complex clinical variables. We analyzed the relationship between multiple cardiovascular (CV) risk factors and different stages of coronary artery disease (CAD) using the BQR model in a vessel-specific manner. METHODS: From the data of 1,463 patients obtained from the PARADIGM (NCT02803411) registry, we analyzed the lumen diameter stenosis (DS) of the three vessels: left anterior descending (LAD), left circumflex (LCx), and right coronary artery (RCA). Two models for predicting DS and DS changes were developed. Baseline CV risk factors, symptoms, and laboratory test results were used as the inputs. The conditional 10%, 25%, 50%, 75%, and 90% quantile functions of the maximum DS and DS change of the three vessels were estimated using the BQR model. RESULTS: The 90th percentiles of the DS of the three vessels and their maximum DS change were 41%-50% and 5.6%-7.3%, respectively. Typical anginal symptoms were associated with the highest quantile (90%) of DS in the LAD; diabetes with higher quantiles (75% and 90%) of DS in the LCx; dyslipidemia with the highest quantile (90%) of DS in the RCA; and shortness of breath showed some association with the LCx and RCA. Interestingly, High-density lipoprotein cholesterol showed a dynamic association along DS change in the per-patient analysis. CONCLUSIONS: This study demonstrates the clinical utility of the BQR model for evaluating the comprehensive relationship between risk factors and baseline-grade CAD and its progression.

Incidence and natural history of coronary artery aneurysm developing after drug-eluting stent implantation.

AIMS: There is a growing concern about the occurrence of coronary artery aneurysms (CAAs) after drug-eluting stent (DES) implantation and their long-term course. We assessed the occurrence and the factors affecting the long-term outcome of DES-associated CAA. METHODS AND RESULTS: We analyzed 3,612 consecutive patients (4,419 lesions) who underwent follow-up angiography after DES implantation. All 34 CAAs (0.76% per lesion) in 29 patients (0.8% per patient) were detected at follow-up, and the mean elapsed time from DES implantation to CAA diagnosis was 414 ± 213 days. Angiographically, CAAs developed almost exclusively in complex (type B2/C) de novo lesions (30 [88.2%] of 34 lesions), and lesion length was significantly greater in patients with CAA than without CAA (26.9 ± 9.03 vs 23.1 ± 7.14 mm; P = .004). Myocardial infarction with stent thrombosis occurred in 5 patients with CAA (17.2%), 4 of whom were on aspirin only without clopidogrel. CONCLUSION: Although CAAs rarely develop after DES implantation and show mostly favorable clinical courses, long-term maintenance of clopidogrel therapy might be required to minimize occurrence of adverse clinical events resulting from stent thrombosis.

Hemorheological abnormalities in stable angina and acute coronary syndromes.

The pathophysiological abnormalities of stable angina (SA) and acute coronary syndromes (ACS) may, in part, be promoted by fluid forces associated with local blood flow and hence by the rheological properties of blood. This study evaluated several hemorheological parameters in 16 healthy controls and in 16 SA, 18 unstable angina (UA) and 19 acute myocardial infarct (AMI) patients; all patients underwent diagnostic angiography following blood sampling. Rheological measurements included whole blood viscosity, plasma viscosity and RBC aggregation via erythrocyte sedimentation rate (ESR) and Myrenne aggregometer indices. Compared to controls, RBC aggregation was significantly elevated in all patient groups (p<0.001), with the rank being AMI>UA>SA. RBC aggregability as tested in 70 kDa dextran exceeded control in all patients. Blood viscosity values calculated at 40% Hct, plasma viscosity and yield shear stress values followed the same pattern (AMI>UA>SA>control); increases of inflammatory markers (i.e., WBC count, hs-CRP) were elevated in all patient groups in the order AMI>UA>SA. Our study thus indicates an association between hemorheological abnormalities and the severity of coronary artery disease, and suggests the merit of evaluating whether therapeutic interventions that normalize blood rheology may reduce the incidence and/or progression of coronary artery disease.