Transient ischemic dilation in patients with diabetes mellitus: prognostic value and effect on clinical outcome after coronary revascularization.

BACKGROUND We prospectively evaluated the incremental prognostic value of transient ischemic dilation (TID) in patients with type 2 diabetes mellitus during long-term follow-up and estimated cardiac death and nonfatal myocardial infarction (MI) using traditional approaches of prognostication to more recent methods. METHODS AND RESULTS A total of 672 consecutive diabetic patients with available rest and stress gated myocardial perfusion single-photon emission computed tomographic data were enrolled. Stepwise Cox regression analysis was used to estimate cardiac death or nonfatal MI. Risk reclassification was calculated, and an exploratory analysis was performed to evaluate the effect of coronary revascularization on event-free survival. Adding TID to a multivariable model, including age, history of MI, stress type, poststress left ventricular ejection fraction, and stress-induced myocardial ischemia, improved discrimination of cardiac death or nonfatal MI (C statistic, 0.74-0.82; P=0.01; adjusted hazard ratio, 3.6; P<0.0001) and led to a net reclassification improvement of 0.39 (95% confidence interval, 0.14-0.64). Revascularization had a significant effect on event-free survival (adjusted hazard ratio, 0.25; P<0.001), with significant interactions between revascularization and poststress left ventricular ejection fraction, revascularization and stress-induced myocardial ischemia, and revascularization and TID (all P<0.01) CONCLUSIONS: TID provides independent and incremental prognostic information for the prediction of cardiac death or nonfatal MI in patients with diabetes mellitus. The addition of TID to a prediction model based on cardiovascular risk factors, left ventricular ejection fraction, and ischemia significantly improves risk discrimination and reclassification for incident cardiac events. The effect of revascularization seems to be influenced by left ventricular systolic function, stress-induced myocardial ischemia, and TID.