Myocardial Revascularization in Patients With Ischemic Cardiomyopathy: For Whom and How

Abstract

Background Myocardial revascularization has been advocated to improve myocardial function and prognosis in ischemic cardiomyopathy (ICM). We discuss the evidence for revascularization in patients with ICM and the role of ischemia and viability detection in guiding treatment. Methods and Results We searched for randomized controlled trials evaluating the prognostic impact of revascularization in ICM and the value of viability imaging for patient management. Out of 1397 publications, 4 randomized controlled trials were included, enrolling 2480 patients. Three trials (HEART [Heart Failure Revascularisation Trial], STICH [Surgical Treatment for Ischemic Heart Failure], and REVIVED [REVascularization for Ischemic VEntricular Dysfunction]-BCIS2) randomized patients to revascularization or optimal medical therapy. HEART was stopped prematurely without showing any significant difference between treatment strategies. STICH showed a 16% lower mortality with bypass surgery compared with optimal medical therapy at a median follow-up of 9.8 years. However, neither the presence/extent of left ventricle viability nor ischemia interacted with treatment outcomes. REVIVED-BCIS2 showed no difference in the primary end point between percutaneous revascularization or optimal medical therapy. PARR-2 (Positron Emission Tomography and Recovery Following Revascularization) randomized patients to imaging-guided revascularization versus standard care, with neutral results overall. Information regarding the consistency of patient management with viability testing results was available in ≈65% of patients (n=1623). No difference in survival was revealed according to adherence or no adherence to viability imaging. Conclusions In ICM, the largest randomized controlled trial, STICH, suggests that surgical revascularization improves patients' prognosis at long-term follow-up, whereas evidence supports no benefit of percutaneous coronary intervention. Data from randomized controlled trials do not support myocardial ischemia or viability testing for treatment guidance. We propose an algorithm for the workup of patients with ICM considering clinical presentation, imaging results, and surgical risk.

Keywords: coronary artery bypass surgery; hibernation; ischemic cardiomyopathy; myocardial ischemia; myocardial revascularization; myocardial viability; percutaneous coronary intervention.

Figure 1. Study selection according to the preferred reporting items for systematic reviews and meta‐analyses: The Preferred Reporting Items for Systematic Reviews and Meta‐Analyses Statement.

RCT indicates randomized controlled trial.

Figure 2. Effect of viability‐guided management on all‐cause and cardiac mortality in randomized controlled trials of patients with ischemic cardiomyopathy., , ,

No difference in the event rate was observed in patients in whom revascularization was performed in adherence to the results of viability assessment versus in those labeled as nonadherent. HEART indicates Heart Failure Revascularisation Trial; PARR‐2, Positron Emission Tomography and Recovery Following Revascularization; REVIVED‐BCIS2, Study of Efficacy and Safety of Percutaneous Coronary Intervention to Improve Survival in Heart Failure; and STICH, Surgical Treatment for Ischemic Heart Failure.

Figure 3. Proposal of a management algorithm for patients with ischemic cardiomyopathy.

In patients with anginal symptoms, complete coronary revascularization with CABG should “probably” be performed in the presence of significant inducible myocardial ischemia (>15% of the LV) to improve prognosis. CABG should “probably” also be performed in patients with evidence of extensive hibernating myocardium (>7% of the LV) on noninvasive imaging (PET or cMRI if available). A preference to CABG should also be given in patients with diabetes. In the absence of significant hibernating myocardium, a heart team evaluation should be performed with preference to OMT and consideration for coronary revascularization (surgical if feasible) only if with low surgical risk. PCI may be considered factoring the SYNTAX scores in selected cases when surgical risk is unacceptable. CABG indicates coronary artery bypass graft; cMRI, cardiac magnetic resonance imaging; F‐FDG, F‐fluorodeoxyglucose; LV, left ventricle; OMT, optimal medical therapy; PCI, percutaneous coronary intervention; PET, positron emission tomography; and SPECT, single‐photon emission computed tomography.