The prognostic impact of inducible ischemia in severe ischaemic cardiomyopathy: a randomised comparison of medical therapy and revascularisation

Abstract Background The presence of inducible myocardial ischaemia is used to select patients with stable coronary artery disease for revascularisation, based on observational data in patients with preserved left ventricular function. It is unclear if identification of a substrate for ischaemia is prognostic in patients with severe ischaemic left ventricular systolic dysfunction (LVSD). Purpose To determine if the extent of inducible ischaemia by stress perfusion CMR relates to clinical outcomes and/or the response to revascularisation in patients with ischaemic LVSD. Methods Patients enrolled in the REVIVED-BCIS2 randomised trial were eligible for inclusion if they had undergone stress perfusion CMR prior to randomisation (1). Visual assessment of myocardial perfusion and late gadolinium enhancement (LGE) was performed by an independent core laboratory, by consensus of two expert readers who were blinded to trial-group assignment and clinical or outcome data. For this analysis, segmental ischaemia was classified in a binary manner and the overall volume of ischaemia is expressed in relation to total LV mass, defined as [number of ischaemic segments]/16 * 100. The primary composite outcome was all-cause death or aborted sudden death. Secondary outcomes included left ventricular ejection fraction change at 6 and 12-months, cardiovascular death and sustained ventricular arrhythmias. Data are presented as median [IQR] or mean ± standard deviation. Results Of 700 participants enrolled, stress perfusion CMR was acquired in 200, 181 of whom had scans of sufficient quality for core laboratory analysis (91 randomised to percutaneous coronary intervention and 90 to optimal medical therapy; age 69±8 years, 86% male, 40% diabetic, baseline jeopardy score 10 [8-12]). On CMR, LVEF was 28±8%, scar burden was 18% [9-26] and ischaemic burden was 31% [13-56]. There was no association between ischaemic burden and the primary outcome (HR 1.0, p=0.997, CI 0.92-1.09) or any of the secondary outcomes (Figure 1). There was no relationship between ischaemia and randomised treatment group (Figure 2). Conclusion The REVIVED-BCIS2 trial incudes the largest cohort to date of stress perfusion CMR in severe LVSD, randomised to relief of ischaemia or medical therapy alone. In this study, ischaemic burden was not associated with clinical outcomes or the outcome following revascularisation.Figure 1 – HRs for 10% ischaemic burdenFigure 2 - KM plots for primary outcome