The effect of chronic total coronary occlusion percutaneous coronary intervention on absolute perfusion in remote myocardium

Background Successful revascularization of a chronic total coronary occlusion (CTO) impacts coronary physiology of the remote myocardial territory. Purpose This study evaluated the effect of CTO percutaneous coronary intervention (PCI) on changes in absolute perfusion in remote myocardium as assessed by serial [15O]H2O positron emission tomography (PET) perfusion imaging. Methods A total of 164 patients underwent [15O]H2O PET imaging at baseline and 3 months after successful single-vessel revascularization of a CTO to evaluate changes in hyperemic myocardial blood flow (hMBF) and coronary flow reserve (CFR) in the remote myocardial territory supplied by both non-target coronary arteries. Results Remote hMBF and CFR improved (2.29±0.67 to 2.48±0.75 mL min–1 g–1 and 2.48±0.76 to 2.74±0.85, respectively) after CTO revascularization (p<0.01 for both). Absolute perfusion indices in the CTO vessel and the remote myocardium showed a positive linear correlation, both before (r=0.75, p<0.01 and r=0.77, p<0.01 for hMBF and CFR, respectively) and after (hMBF: r=0.87, p<0.01 and CFR: r=0.81, p<0.01) CTO PCI. Absolute increases in remote myocardial perfusion were largest in patients with a higher increase in hMBF (βeta [β] 0.56; 95% CI: 0.47–0.65; p<0.01) and CFR (β 0.51 (0.42–0.60); p<0.01) in the CTO territory, independent of clinical, angiographic and procedural characteristics. Furthermore, baseline (hMBF: β −0.24 (−0.39, −0.08); p<0.01 and CFR: β −0.26 (−0.41, −0.11); p<0.01) and post-PCI perfusion (hMBF: β 0.36; (0.27, 0.46); p<0.01 and CFR: β 0.30 (0.21, 0.40); p<0.01) in the CTO vessel were independently associated with the increase in remote myocardial perfusion after CTO PCI. Conclusions An overall increase in remote myocardial perfusion was observed following CTO PCI. Absolute perfusion indices in the remote myocardium showed a positive linear correlation with perfusion in the CTO vessel, before and after CTO revascularization. Importantly, baseline, post-PCI and the absolute increase in perfusion in the CTO territory were independently associated with increases in remote myocardial perfusion after revascularization. FUNDunding Acknowledgement Type of funding sources: None. Figure 1 Figure 2

Infarct-related chronic total coronary occlusion and the risk of ventricular tachyarrhythmic events in out-of-hospital cardiac arrest survivors

Introduction Chronic total coronary occlusion (CTO) has been identified as a risk factor for ventricular arrhythmias, especially a CTO in an infarct-related artery (IRA). This study aimed to evaluate the effect of an IRA-CTO on the occurrence of ventricular tachyarrhythmic events (VTEs) in out-of-hospital cardiac arrest survivors without ST-segment elevation. Methods We conducted a post hoc analysis of the COACT trial, a multicentre randomised controlled trial. Patients were included when they survived index hospitalisation after cardiac arrest and demonstrated coronary artery disease on coronary angiography. The primary endpoint was the occurrence of a VTE, defined as appropriate implantable cardioverter-defibrillator (ICD) therapy, sustained ventricular tachyarrhythmia or sudden cardiac death. Results A total of 163 patients from ten centres were included. Unrevascularised IRA-CTO in a main vessel was present in 43 patients (26%). Overall, 61% of the study population received an ICD for secondary prevention. During a follow-up of 1 year, 12 patients (7.4%) experienced at least one VTE. The cumulative incidence rate of VTEs was higher in patients with an IRA-CTO compared to patients without an IRA-CTO (17.4% vs 5.6%, log-rank p = 0.03). However, multivariable analysis only identified left ventricular ejection fraction < 35% as an independent factor associated with VTEs (adjusted hazard ratio 8.7, 95% confidence interval 2.2–35.4). A subanalysis focusing on CTO, with or without an infarct in the CTO territory, did not change the results. Conclusion In out-of-hospital cardiac arrest survivors with coronary artery disease without ST-segment elevation, an IRA-CTO was not an independent factor associated with VTEs in the 1st year after the index event.

Cholesterol Efflux and Collateral Circulation in Chronic Total Coronary Occlusion: Effect‐Circ Study

Background The mechanism through which high‐density lipoprotein (HDL) induces cardioprotection is not completely understood. We evaluated the correlation between cholesterol efflux capacity (CEC), a functional parameter of HDL, and coronary collateral circulation (CCC). We additionally investigated whether A1BP (apoA1‐binding protein) concentration correlates with CEC and CCC. Methods and Results In this case‐control study, clinical and angiographic data were collected from 226 patients (mean age, 58 years; male, 72%) with chronic total coronary occlusion. CEC was assessed using a radioisotope and J774 cells, and human A1BP concentration was measured using enzyme‐linked immunosorbent assay. Differences between the good and poor CCC groups were compared, and associations between CEC, A1BP, and other variables were evaluated. Predictors of CCC were identified by multivariable logistic regression analysis. The CEC was higher in the good than in the poor CCC group (22.0±4.6% versus 20.2±4.7%; P =0.009). In multivariable analyses including age, sex, HDL‐cholesterol levels, age (odds ratio [OR], 0.96; P =0.003), and CEC (OR, 1.10; P =0.004) were identified as the independent predictors of good CCC. These relationships remained significant after additional adjustment for diabetes mellitus, acute coronary syndrome, and Gensini score. The A1BP levels were not significantly correlated with CCC (300 pg/mL and 283 pg/mL in the good CCC and poor CCC groups, respectively, P =0.25) or CEC. Conclusions The relationship between higher CEC and good CCC indicates that well‐functioning HDL may contribute to CCC and may be cardioprotective; this suggests that a specific function of HDL can have biological and clinical consequences.