Long-term prognostic value of coronary flow velocity reserve in patients with hypertrophic cardiomyopathy: 9-year follow-up results from SZEGED study

Reduction in coronary flow velocity reserve (CFR) is a recognized feature in hypertrophic cardiomyopathy (HCM). We sought to assess the long-term prognostic value of CFR by pulsed-wave Doppler transesophageal echocardiography (TEE) in HCM patients. The study comprised 20 patients with typical features of HCM. The patients were enrolled in 1999. All patients underwent a standard transthoracic echo-Doppler study to evaluate left ventricular function and a stress vasodilator TEE study to evaluate CFR. The success rate of follow-up was 18 out of 20 (90%). During a mean follow-up of 90 ± 24 months, four patients suffered cardiovascular death (2 sudden cardiac deaths and 2 strokes). The other seven patients underwent invasive procedures (coronary angiography, implantable cardioverter defibrillator implantation, percutaneous transluminal septal myocardial ablation) or showed cerebrovascular events. Using receiver operator characteristic analysis, CFR < 2.35 was a significant predictor for cardiovascular event-free survival (sensitivity 91%, specificity 71%, area under the curve 74%, P = 0.05). Multivariable regression analysis showed that only CFR (hazard ratio (HR) 4.21, P < 0.05) was an independent predictor of cardiovascular event-free survival. Despite the relatively small number of patients involved in the study, results could suggest that CFR should be considered as an independent predictor for future cardiovascular events in HCM patients. However, further studies with larger HCM patient populations are warranted.