Ischemic Burden Reduction and Long-Term Clinical Outcomes After Chronic Total Occlusion Percutaneous Coronary Intervention

OBJECTIVES The authors sought to evaluate the impact of ischemic burden reduction after chronic total occlusion (CTO) percutaneous coronary intervention (PCI) on long-term prognosis and cardiac symptom relief. BACKGROUND The clinical benefit of CTO PCI is questioned. METHODS In a high-volume CTO PCI center, 212 patients prospectively underwent quantitative [O-15]H2O positron emission tomography perfusion imaging before and three months after successful CTO PCI between 2013-2019. Perfusion defects (PD) (in segments) and hyperemic myocardial blood flow (hMBF) (in ml . min(-1) . g(-1)) allocated to CTO areas were related to prognostic outcomes using unadjusted (Kaplan-Meier curves, log-rank test) and risk-adjusted (multivariable Cox regression) analyses. The prognostic endpoint was a composite of all-cause death and nonfatal myocardial infarction. RESULTS After a median [interquartile range] of 2.8 years [1.8 to 4.3 years], event-free survival was superior in patients with >= 3 versus <3 segment PD reduction (p < 0.01; risk-adjusted p = 0.04; hazard ratio [HR]: 0.34 [95% confidence interval (CI): 0.13 to 0.93]) and with hMBF increase above (Delta >= 1.11 ml . min(-1) . g(-1)) versus below the population median (p < 0.01; risk-adjusted p < 0.01; HR: 0.16 [95% CI: 0.05 to 0.54]) after CTO PCI. Furthermore, event-free survival was superior in patients without versus any residual PD (p < 0.01; risk-adjusted p = 0.02; HR: 0.22 [95% CI: 0.06 to 0.76]) or with a residual hMBF level >2.3 versus <= 2.3 ml . min(-1) . g(-1) (p < 0.01; risk-adjusted p = 0.03; HR: 0.25 [95% CI: 0.07 to 0.91]) at follow-up positron emission tomography. Patients with residual hMBF >2.3 ml . min(-1) . g(-1) were more frequently free of angina and dyspnea on exertion at long-term follow-up (p = 0.04). CONCLUSIONS Patients with extensive ischemic burden reduction and no residual ischemia after CTO PCI had lower rates of all-cause death and nonfatal myocardial infarction. Long-term cardiac symptom relief was associated with normalization of hMBF levels after CTO PCI. (C) 2021 by the American College of Cardiology Foundation.

Automated summary

This study aimed to evaluate the impact of ischemic burden reduction after CTO PCI on long-term prognosis and cardiac symptom relief. Through various analyses, it was found that ischemic burden reduction and residual ischemia levels were closely related to prognosis outcomes and relief of cardiac symptoms.