393Ischemic burden by vasodilator stress CMR predicts long-term all-cause death and the effect of revascularization in patients with known or suspected stable ischemic heart disease

Abstract Background In patients with stable ischemic heart disease (SIHD) the effect of revascularization on all-cause death (the most verifiable clinical event) is unknown. Objectives We explored the potential of the ischemic burden as derived from vasodilator stress cardiovascular magnetic resonance (CMR) to guide decision-making in this scenario. Methods In a large prospective multicenter registry, we recruited 6389 patients (mean age 65±11 years, 38% female) submitted to undergo vasodilator stress CMR for known or suspected SIHD. Baseline and CMR characteristics were prospectively recorded. The ischemic burden (at vasodilator stress first-pass perfusion imaging) and necrosis extent (at late enhancement imaging) were computed (17-segment model). The effect of CMR-related revascularization (within the following three months) on all-cause death (revised using the unified regional electronic health system registry) was explored. Results During a 5.75-year median follow-up, 717 (11.2%) all-cause deaths were documented. In multivariable analyses, more extensive ischemic burden (per 1-segment increase) independently related to all-cause death (1.05 [1.03–1.07], p<0.001). In 1034 patients (517 revascularized, 517 non-revascularized) strictly 1:1 matched for the independent predictors of outcome and of undergoing CMR-related revascularization (age, diabetes mellitus, male sex, LVEF, ischemic burden and necrosis extent), CMR-related revascularization did not significantly alter all-cause death rate (13.3% vs. 13.3%, p=0.54). Nevertheless, a potent interaction existed with the ischemic burden (p<0.001). CMR-related revascularization independently reduced the risk of all-cause death in 430 patients with ischemic burden >5 segments (9.3% vs. 16.3%, HR 0.56 [0.32–0.98], p=0.02) but it independently increased risk in 604 patients with ischemic burden ≤5 segments (16.2% vs. 11.3%, HR 1.59 [1.03–2.45], p=0.037). Figure 1. CMR-related revascularization Conclusions In patients with known or suspected stable ischemic heart disease the ischemic burden as derived from vasodilator stress CMR can be helpful to predict the effect of revascularization on long-term all-cause death. Acknowledgement/Funding Funded by “Instituto de Salud Carlos III”/FEDER (PIE15/00013, PI17/01836, and CIBERCV16/11/00486 grants) and Generalitat Valenciana (GV/2018/116).