Prognostic value of stress perfusion CMR in patients without known coronary artery disease: a real-world single-center experience

Background Stress perfusion cardiovascular magnetic resonance (CMR) is widely used to assess myocardial ischemia, yet its prognostic evidence—particularly in patients without known coronary artery disease (CAD)—is less extensive than that of older imaging modalities. Purpose We aimed to evaluate the prognostic value of stress CMR in a contemporary cohort of patients without known CAD. Methods We conducted a single-center retrospective study including patients without known CAD who underwent adenosine stress CMR on a 1.5-T system between 2019 and 2023. Major adverse cardiovascular events (MACE), defined as all-cause death, non-fatal myocardial infarction (MI), cardiovascular hospitalization and late coronary revascularization, were recorded as the primary endpoint. Secondary outcomes were defined as each individual component of the composite endpoint. The prognostic value of inducible myocardial ischemia (≥2 segments) and ischemic-pattern late gadolinium enhancement (LGE) (previously unknown myocardial infarction) was evaluated using survival and Cox regression analyses. Results A total of 558 patients were included (median age 68.7 years; 57.5% male). Patients showed a high cardiovascular risk burden, including hypertension (73%), dyslipidaemia (65%), smoking (31%), diabetes mellitus (27%), chronic kidney disease (27%), and atrial fibrillation (22%). Stress CMR was positive for inducible myocardial ischemia in 14.5% of patients and ischemic LGE in 15.8%, with 4.5% presenting both findings. Concomitant non-ischemic LGE was identified in 11.3%. Over a median follow-up of 2.9 years, the primary endpoint ocorred in 16.3%. Survival analysis showed a higher incidence of the primary endpoint in patients with inducible ischemia, ischemic LGE, or both (log-rank p<0.001). Increase in event rates was also observed for all-cause mortality (log-rank p=0.005), non-fatal MI (log-rank p=0.018), cardiovascular hospitalization (log-rank p=0.013) and late coronary revascularization (log-rank p<0.001) (figure 1). In multivariable Cox regression analysis, age (HR 1.03, 95% CI 1.01–1.04, p<0.001), LV ejection fraction (HR 0.97, 95% CI 0.96–0.98, p<0.001), inducible myocardial ischemia (HR 1.67, 95% CI 1.25–2.23, p<0.001), and ischemic LGE (HR 1.66, 95% CI 1.24–2.23, p=0.001) were independent predictors of the primary endpoint. Conclusion Stress CMR offers robust prognostic information in patients without known CAD. Inducible ischemia and ischemic LGE were independently associated with an increased risk of MACE. Importantly, stress CMR also revealed a substantial number of previously unrecognized MI, a finding with direct implications for patient management.