Long‐term prognostic role of coronary flow velocity reserve in patients with aortic valve stenosis – insights from the SZEGED Study

INTRODUCTION: Coronary flow velocity reserve (CFR) is markedly reduced in severe aortic valve stenosis (AS). Independent prognostic value of pulsed-wave Doppler echocardiography-derived CFR was seen in a variety of diseases. However, the prognostic significance of CFR by pulsed-wave Doppler echocardiography has never been evaluated in patients with AS. METHODS: A total of 49 AS patients (mean age: 63 +/- 9 years, 26 men) were enrolled in this prospective follow-up study; they all had undergone standard transthoracic Doppler-echo study, coronary angiography and dipyridamole stress transoesophageal echocardiography as CFR measurement. RESULTS: During a mean follow-up of 82 +/- 38 months, 18 patients suffered cardiovascular death and one patient had non-fatal stroke. Other two patients underwent reoperation of dysfunctional prosthetic aortic valve. Using receiver operator curve (ROC) analysis, CFR <2.13 had the highest accuracy in predicting cardiovascular outcome (sensitivity 90%, specificity 46%, area under the curve 66%, P = 0.02). By univariable analysis, diabetes mellitus, hypertension, presence of coronary artery disease and lower CFR were significant predictors of cardiovascular morbidity and mortality. Multivariable regression analysis showed that only lower CFR [hazard ratio (HR) 1.67, 95% CI of HR: 1.05-4.29, P < 0.05] was independent predictor of cardiovascular outcome. DISCUSSION: Long-term prognostic significance of CFR for prediction of cardiovascular morbidity and mortality has been demonstrated during a 9-year follow-up in patients with AS. Despite a relatively small number of patients were followed, CFR was found to be an independent predictor for future cardiovascular events in AS patients.