Lim, Seong‐Hoon

Background: About 25% of patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) have chronic total occlusion (CTO) at non-culprit artery. However, the prognostic impact of CTO in these patients is still unclear. Aims: We aimed to investigate the impact of CTO at non-culprit artery on 1-year mortality in patients with AMI-CS using the multicenter registry of cardiogenic shock. Methods: A total of 1,247 patients presented with cardiogenic shock (CS) were enrolled in the SMART-RESCUE registry between January 2014 and December 2018. After exclusion of non-ischemic cause shock, ischemic cardiomyopathy, failed or no revascularization, vasospasm, and patients undergoing coronary artery bypass surgery, 695 patients underwent percutaneous coronary intervention (PCI). Among these, we analyzed 536 patients with multivessel disease (MVD) according to the presence of CTO at non-culprit artery. The study endpoint was a 1-year all-cause mortality. We also examined the incidence of 1-year cardiac death, and in-hospital death or renal replacement therapy (RRT). Results: A 141 patients (26.3%) of study population had CTO lesion at non-culprit artery. The CTO group had more patients with diabetes mellitus, and lesser patients with ST-elevation myocardial infarction. Although initial left ventricular ejection fraction was lower in CTO group (28.5 vs. 34.1%, P=0.005), initial systolic blood pressure (73.8 vs. 73.2 mmHg, P=0.822) and the level of lactate (6.6 vs. 6.4 mmol/L, P=0.804) were similar in both groups. Venoarterial extracorporeal membrane oxygenation was applied in 206 patients (38.4%), and its use rate was comparable in 2 groups (40.4 vs. 37.7%, P=0.571). Pre- (32.9 vs. 22.9, P <0.001) and post-PCI SYNTAX score (16.7 vs. 5.3, P <0.001) was significantly higher in CTO group. In CTO group, 53 patients (37.6%) had CTO at left main or left anterior descending artery, and only 19 patients (13.5%) in CTO group received PCI for CTO. In multivariate analysis, all-cause mortality at 1-year was significantly higher in CTO group (51.8 vs. 40.5%, hazard ratio [HR] 1.44, 95% confidence interval [CI] 1.09-1.90, P=0.011). The incidences of 1-year cardiac death (45.4 vs. 32.4%, HR 1.55, 95% CI 1.15-2.10, P=0.004) and in-hospital death or RRT (46.8 vs. 36.5%, P=0.031) were also higher in CTO group. Conclusions: Non-culprit CTO lesion was associated with higher 1-year mortality in patients with AMI-CS and multivessel disease.

Background— Coronary stents, drug-eluting stents in particular, have been linked to coronary epicardial endothelial dysfunction after implantation. However, less is known about their impact on coronary microvascular function and their long-term effects on the vasculature. Methods and Results— We evaluated 71 patients (mean age, 53.0±10.1 years) with chest pain and angiographically nonsignificant coronary artery disease 17.1±17.1 months after left anterior descending coronary artery stenting. Seventy-one age- and sex-matched patients (mean age, 53.0±10.3 years) with chest pain but no prior coronary intervention served as controls. Coronary blood flow in response to the endothelium-dependent vasodilator acetylcholine as well as the microvascular (endothelium-independent) coronary flow reserve in response to intracoronary adenosine were evaluated. Quantitative coronary angiography was used to study epicardial diameter changes to acetylcholine. Microcirculatory function was not significantly different between the stenting and control groups (median [interquartile range] coronary flow reserve, 2.9 [2.5–3.4] versus 3.0 [2.4–3.4] mL/min, P =0.24; change of coronary blood flow, 34.9% [−34.4% to 90.0%] versus 54.7% [−5.6% to 104.6%], P =0.18). Both groups exhibited epicardial endothelial dysfunction (−23.0% [−47.4% to −7.6%] versus −20.0% [−40.0% to 0.0%], P =0.4). Results did not differ between patients with drug-eluting stents (n=46) and patients with bare-metal stents (n=24). Conclusions— This study demonstrates that in patients with coronary arteries in which a stent has been placed, coronary microcirculatory and epicardial vascular function are not significantly different from that of an age- and sex-matched population with similar symptoms but nonsignificant coronary artery disease.