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. The clinical benefit of CTO PCI is questioned. In a high-volume CTO PCI center, 212 patients prospectively underwent quantitative [15O]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. 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 (Δ≥1.11ml · 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≤2.3ml · 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 >2.3ml · min-1 · g-1 were more frequently free of angina and dyspnea on exertion at long-term follow-up (p=0.04). 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.
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