The absence of ischemia in patients evaluated using vasodilator stress perfusion cardiac magnetic resonance (CMR) was associated with low risk of angiographically verified high-risk coronary artery disease (CAD) and adverse cardiovascular events, according to a recent study published in JACC: Cardiovascular Imaging.

Using data from the Stress CMR Perfusion Imaging in the U.S. Study (SPINS) registry, Benedikt Bernhard, MD, et al., included 4,144 patients (61 ± 13 years, 54% male) in their analysis. Study outcomes included composites of angiographic new diagnosis of left main (LM) disease, high-risk multivessel coronary disease (MVD), acute nonfatal myocardial infarction (MI) and cardiovascular death over a four-year follow-up period.

Vasodilation stress perfusion CMR identified ischemia in 18% of patients, and prior infarct was present in 27% of patients. At year four, 8.1% of patients experienced the primary composite outcome, including 4.4% with new diagnoses of LM/MVD, 2.3% with acute MI and 1.4% with cardiovascular death.

Overall, the strongest multivariable predictor of the composite outcome was presence of ischemia (adjusted hazard ratio, 4.55; 95% CI, 3.32-6.25; p<0.001) and adding ischemia extent significantly improved model performance. In addition, ischemia extent was independently associated with the composite outcome (adjusted hazard ratio, 1.11; 95%CI, 1.07-1.15; p<0.001).

"Our data show a clear, graded association between the extent of ischemia, quantified by the number of AHA segments involved, and the likelihood of adverse outcomes," add the authors. "This observation emphasizes that not only the presence but also the severity of ischemia carries independent prognostic value."