Stress CMR ischaemic burden and long-term mortality in left ventricular systolic dysfunction: a multicentre registry study

Stress perfusion cardiovascular magnetic resonance (CMR) integrates the assessment of myocardial ischaemia, scar, and function. Its incremental prognostic value in patients with left ventricular (LV) systolic dysfunction remains uncertain.

We analysed a prospective multicentre registry of consecutive patients undergoing vasodilator stress perfusion CMR at three French centres (2008–24). Patients with CMR-derived LVEF < 50% were included. The primary end point was all-cause mortality. Associations were estimated with multivariable Cox models. Incremental prognostic value of ischaemia and late gadolinium enhancement (LGE) beyond clinical factors and LVEF was assessed by likelihood ratio χ², continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI). Among 5977 patients (79% men; age 66 ± 12 years, mean LVEF 42 ± 7%), inducible ischaemia was present in 19% (mean extent 2.4 ± 1.2 segments). Over a median follow-up of 9 years, 1343 patients (22%) died. Ischaemic segment extent was independently associated with mortality (HR per segment 1.11; 95% CI, 1.06–1.15; P < 0.001). Adding ischaemia and LGE to clinical factors and LVEF improved model fit and reclassification (global χ² increased from 707 to 728; NRI 0.217; IDI 0.004; all P < 0.001). Findings were consistent across LVEF subgroups (40–50% and <40%). In secondary analyses among patients with ischaemia, outcomes differed by subsequent revascularization status; these findings are observational and hypothesis-generating.

In patients with LVEF < 50%, ischaemic burden on stress CMR is independently associated with long-term mortality beyond clinical factors, LVEF and LGE. Integrating ischaemia and scar metrics provides incremental prognostic information that may aid risk stratification using stress CMR in LV systolic dysfunction.