Abstract 3355: Coronary Microvascular Reactivity to Adenosine Predicts Adverse Outcome in Women Evaluated for Suspected Ischemia: Results from the NHLBI Women’s Ischemia Syndrome Evaluation (WISE)
Background: Altered coronary reactivity occurs in women with chest discomfort without significant coronary atherosclerosis. The endothelial-dependent component of this altered reactivity has been linked with adverse outcomes, while the non endothelial-dependent component has received limited attention. Accordingly, the relationship between non endothelial-dependent microvascular coronary reactivity and adverse outcomes in women evaluated for suspected ischemia remains uncertain.
Methods: As part of the NHLBI-sponsored Women’s Ischemia Syndrome Evaluation (WISE), we investigated relationships between adverse outcomes and coronary flow reserve (CFR) in 190 women referred for angiography to evaluate suspected ischemia. This analysis focused on CFR to intracoronary adenosine measured at entry and major adverse outcomes (death, nonfatal MI, nonfatal stroke or hospitalization for heart failure) occurring during protocol directed follow up. Results: At 5 years follow up, we observed significant (p<0.05) associations between tercile of CFR and major adverse outcomes. Using receiver operator characteristic analysis, a CFR <2.32 was the optimal threshold for major adverse outcomes (CFR <2.32 event rate 26.7% and ≥2.32 event rate 12.2%, p=0.01). Although there was an inverse association between CFR and increased CAD severity by angiography, the association between CFR and major adverse outcomes remained significant among the 153 women with no obstructive CAD. Using multivariable regression modeling, CFR significantly improved prediction of major adverse outcomes over CAD severity (p=0.03) and was independent of diabetes.
Conclusions: Among women with suspected ischemia and atherosclerosis risk factors, non-endothelial-dependent coronary microvascular reactivity to adenosine was an independent predictor of major adverse outcomes. These findings suggest that coronary microvessels represent a novel target for new treatments to limit adverse outcomes in women.