Prognostic value of stress cardiovascular magnetic resonance in asymptomatic patients without known coronary artery disease

Objectives A few studies suggest a significant prognostic value of silent myocardial ischaemia detected in asymptomatic patients. However, the current guidelines do not recommend stress testing in asymptomatic individuals. To assess the long-term prognostic value of vasodilator stress perfusion cardiovascular magnetic resonance (CMR) in asymptomatic individuals without known coronary artery disease (CAD). Methods Between 2009 and 2011, a retrospective cohort study with a median follow-up of 9.2 years (interquartile range: 7.8-9.6) included 1,027 consecutive asymptomatic individuals with >= 2 cardiovascular risk factors but without known known CAD referred for stress CMR. Major adverse cardiovascular events (MACE) included cardiovascular mortality and nonfatal myocardial infarction (MI). Results Among 1,027 asymptomatic subjects, 903 (87.9%) (mean age 70.6 +/- 12.4 years and 46.2% males) completed the follow-up, and 91 had MACE (10.1%). Using Kaplan-Meier analysis, silent ischaemia and unrecognised MI were associated with MACE (hazard ratio [HR]: 8.70; 95% CI: 5.79-13.10 and HR: 3.40; 95% CI: 2.15-5.38, respectively; both p < 0.001). In multivariable stepwise Cox regression, silent ischaemia and unrecognised MI were independent predictors of MACE (HR: 6.66; 95% CI 4.41-9.23; and HR: 2.42; 95% CI 1.23-3.21, respectively; both p < 0.001). The addition of silent ischaemia and unrecognised MI led to improved model discrimination for MACE (change in C statistic from 0.66 to 0.82; NRI = 0.497; IDI = 0.070). Conclusions Silent ischaemia and unrecognised MI are good long-term predictors for the incidence of MACE in selected asymptomatic individuals with multiple risk factors and without known CAD. These stress CMR parameters have incremental long-term prognostic value to predict MACE over traditional risk factors.