Prognostic Value of Heart Rate Reserve in Exercise Treadmill Test after Coronary Revascularization

Objective: The aim of this study was to assess heart rate (HR) responses to exercise in the prediction of the major adverse cardiovascular events (MACE) in patients with revascularization. Methods: We retrospectively analyzed 253 patients with successful revascularization and exercise treadmill test (ETT) 4 months later in asymptomatic status. MACE was defined as cardiac death, nonfatal myocardial infarction and revascularization. HR reserve as index of chronotropic response was calculated as (peak HR-baseline HR) ×100/(220-age-baseline HR). Impaired HR reserve was defined as achievement of <80% in patients without betablockers (BB) and <62% in patients with BB. HR recovery at 1minute (HRR 1min) was calculated as peak HR–HR at recovery 1minute. Impaired HRR 1min was defined as a decrease of ≤12bpm. Results: HRR 1min and HR reserve were significantly lower in MACE group. In multivariate analysis, HRR 1min and HR reserve were independent predictors for the MACE. The odds ratios (OR) for the MACE in impaired HRR 1min was 4.7 with adjustment. In addition, the OR for the MACE in impaired HR reserve was 4.4 with adjustment. Moreover, the OR for the MACE in patients with both impaired HRR 1min and impaired HR reserve was 7.5 with adjustment. Conclusions: Impaired HRR 1min and HR reserve to exercise could be associated with the MACE in the asymptomatic patients with successful revascularization.