Age- and Gender-Specific Prognostic Cutoff Values of Coronary Flow Velocity Reserve in Vasodilator Stress Echocardiography.

PURPOSE: Coronary flow velocity reserve (CFVR) of the left anterior descending artery is useful for risk stratification during stress echocardiography (SE) as an add-on to regional wall motion abnormalities (RWMA). We sought to provide sex- and age-specific prognostic cutoff values for CFVR.

METHODS

A total of 5,577 patients (2,284 women; 110 age ≥ 85 years) who underwent dipyridamole SE with evaluation of RWMA and CFVR were enrolled in a multicenter prospective SE registry. Death and myocardial infarction were the clinical end points.

RESULTS

During 20 months' median follow-up, 649 events (236 deaths, 413 infarctions) occurred: 288 in women and 38 in patients ≥85 years. At receiver operating characteristics analysis, the best prognostic cutoff value for CFVR was similar for men (2.03) and women (2.02) and consistent across all age strata (<45 years: 2.03; 45-54 years: 2.04; 45-64 years: 2.03; 65-74 and 75-84 years: 2.0) except for patients >85 years, who showed 1.90 as the optimal value. Independent predictors of mortality or myocardial infarction were RWMA (hazard ratio [HR] = 5.42), reduced CFVR (HR = 3.26), resting ejection fraction (HR = 0.98), smoking habit (HR = 1.41), age (HR = 1.02), and prior percutaneous coronary intervention (HR = 1.20) in patients age <85 years; and RWMA (HR = 5.42), smoking habit (HR = 3.24), and resting ejection fraction (HR = 0.97) in those age ≥85 years. CFVR added a prognostic contribution over clinical parameters, resting ejection fraction, and stress-induced RWMA in all age and sex groups except men >85 years.

CONCLUSIONS

A sex-independent value of CFVR ≤2.0 provides the optimal prognostication across all age groups, except for those ≥85 years in whom a cutoff ≤1.90 is needed. Risk stratification is more effective for all age groups when CFVR is combined with RWMA.