Background
Several studies have established the prognostic value of vasodilator stress cardiovascular magnetic resonance (CMR) in broad population of patients with suspected or known coronary artery disease (CAD), but this specific population of asymptomatic patients with known CAD have never been formally evaluated. To assess the long-term prognostic value of vasodilator stress perfusion CMR in asymptomatic patients with obstructive CAD.
Methods
Between 2009 and 2011, consecutive asymptomatic patients with obstructive CAD referred for vasodilator stress CMR were followed for the occurrence of major adverse cardiovascular events (MACE), defined by cardiovascular mortality or recurrent non-fatal myocardial infarction (MI). Uni- and multivariable Cox regressions were performed to determine the prognostic value of myocardial ischemia and myocardial infarction defined by late gadolinium enhancement (LGE) with ischemic pattern.
Results
Among 1529 asymptomatic patients with obstructive CAD, 1342 (87.8%; 67.7 ± 10.5 years, 82.0% males) completed the follow-up (median 8.3 years), and 195 had MACE (14.5%). Patients without stress-induced myocardial ischemia had a low annualized rate of MACE (2.4%), whereas the annualized rate of MACE was higher for patients with mild, moderate, or severe ischemia (7.3%, 16.8%, and 42.2%, respectively; ptrend < 0.001). Using Kaplan–Meier analysis, myocardial ischemia and LGE were associated with MACE (hazard ratio, HR 2.52; 95% CI 1.90–3.34 and HR 2.04; 95% CI 1.38–3.03, respectively; both p < 0.001). In multivariable stepwise Cox regression, myocardial ischemia and LGE were independent predictors of MACE (HR 2.80 95% CI 2.10–3.73, p < 0.001 and HR 1.51; 95% CI 1.01–2.27, p = 0.045; respectively). The addition of myocardial ischemia and LGE led to improved model discrimination for MACE (change in C statistic from 0.61 to 0.68; NRI = 0.207; IDI = 0.021).
Conclusions
Vasodilator stress CMR-induced myocardial ischemia and LGE are good long-term predictors for the incidence of MACE in asymptomatic patients with obstructive CAD.
