BackgroundChronic total occlusion percutaneous coronary intervention (CTO-PCI) can improve angina and left ventricular ejection fraction (LVEF). These benefits were not assessed in populations with heart failure with reduced ejection fraction (HFrEF). We studied the effect of CTO-PCI on left ventricular function and clinical parameters in patients with HFrEF.MethodsUsing cardiovascular magnetic resonance (CMR), we studied 29 patients with HFrEF and evidence of viability and/or ischemia in the territory supplied by a CTO who were successfully treated with CTO-PCI. In patients with multi-vessel disease, non-CTO PCI was also performed. Imaging parameters, clinical status, and brain natriuretic peptide (BNP) levels were evaluated before and 6 months after CTO-PCI.ResultsA decrease in left ventricular end-systolic volume (160 ± 54 ml vs. 143 ± 58 ml; p = 0.029) and an increase in LVEF (31.3 ± 7.4 % vs. 37.7 ± 8 %; p < 0.001) were observed. There were no differences in LVEF improvement between patients who underwent non-CTO PCI (n = 11) and those without this intervention (n = 18); (p = 0.73). The number of segments showing perfusion defects was significantly reduced (0.5 ± 1 vs. 0.2 ± 0.5; p = 0.043). Angina (p = 0.002) and NYHA functional class (p = 0.004) improved, and BNP levels decreased (p = 0.004) after CTO-PCI.ConclusionsIn this group of patients with HFrEF showing CMR evidence of viability and/or ischemia within the territory supplied by the CTO, an improvement in ejection fraction, left ventricular end-systolic volume and ischemia burden was observed after CTO-PCI. Clinical and laboratory parameters also improved.Trial registrationClinicalTrials.gov NCT02570087. Registered 6 October 2015.