Vasodilator stress perfusion CMR for outcome prediction in patients under 45 years with suspected CAD.

BACKGROUND: Although the prognostic value of vasodilator stress cardiovascular magnetic resonance (CMR) is established, it has never been assessed in patients <45 years with suspected coronary artery disease. The aim was to assess the long-term prognostic value of stress CMR to predict mortality in a multicenter cohort of patients <45 years-old. METHODS: Between December 2008 and December 2024, a prospective multicenter registry enrolled all consecutive patients undergoing vasodilator stress CMR at three French centers. For the present retrospective analysis, all patients aged <45 years were included. The primary endpoint was all-cause mortality, assessed through the French National Death Registry. Cox regression analyses were performed to determine the prognostic value of inducible ischemia and late gadolinium enhancement (LGE). RESULTS: Of the 3,671 patients (mean age 38±6 years, 65% males), 102 (2.8%) died after a median follow-up of 6.8 years (interquartile range: 3-11 years). Annualized mortality rates increased gradually with the number of segments of ischemia and LGE (both p-trend<0.001). The extent of ischemia (hazard ratio [HR]: 1.45; 95% confidence interval [CI]: 1.24-1.70) and LGE (HR: 1.56; 95% CI: 1.39-1.75) were both associated with mortality (both p<0.001). After adjustment for traditional prognostic factors, both the extent of ischemia (adjusted HR: 1.26, per 1-segment increase; 95% CI: 1.06-1.51, p=0.011) and LGE (adjusted HR: 1.50, per 1-segment increase; 95% CI: 1.25-1.80, p<0.001) remained independent predictors of mortality. CONCLUSIONS: In patients <45 years undergoing stress CMR, the extent of both inducible ischemia and LGE provide strong and independent prognostic value for predicting all-cause mortality.