Long‐Term Prognostic Significance of Coronary Flow Velocity Reserve in Patients with Significant Coronary Artery Disease Not Involving the Left Anterior Descending Coronary Artery (Results from the SZEGED Study)

Abstract

Coronary flow velocity reserve (CFR) by pulsed Doppler echocardiography is a useful hemodynamic index to evaluate the coronary microcirculatory dysfunction in the left anterior descending coronary artery (LAD). The present study was designed to evaluate the long-term predictive value of CFR for mortality in patients with right (RC) and/or left circumflex coronary artery (CX) stenosis without epicardial LAD disease. A total of 49 patients with significant RC and/or CX stenosis were enrolled in this prospective follow-up study. All patients had undergone coronary angiography demonstrating significant RC and/or CX stenosis without LAD disease and dipyridamole stress transoesophageal echocardiography as CFR measurement. The success rate of follow-up was 43 out of 49 (88%). During a mean follow-up of 97 +/- 29 months, 14 patients suffered cardiovascular deaths (12 sudden cardiac deaths and 2 strokes), and 1 patient died of pulmonal tumor. Patients who died during the follow-up had significantly lower CFR values (1.85 +/- 0.43 vs. 2.31 +/- 0.57, P < 0.05). Using ROC analysis, CFR <2.09 had the highest accuracy in predicting cardiovascular survival (sensitivity 80%, specificity 57%, area under the curve 73%, P = 0.003). The logistic regression model identified only CFR as an independent predictor of survival (hazard ratio [HR] 6.26, 95% CI of HR 1.23-19.61, P = 0.024). Long-term prognostic significance of CFR for the prediction of mortality has been demonstrated during a 9-year follow-up in patients with significant coronary artery disease not involving the LAD.