05/05/2026
!! Heart Rate Recovery After the 6 Min Walk Test Rather Than Distance Ambulated Is a Powerful Prognostic Indicator in Heart Failure With Reduced and Preserved Ejection Fraction !!
Heart rate recovery (HRR) appears to be a robust prognostic marker in heart failure (HF). When using the 6 min walk test (6MWT) in HF, distance ambulated is generally the reference prognostic variable. We hypothesized that HRR after the 6MWT would be a better prognostic measure than distance ambulated.Methods and results A 6MWT and cardiopulmonary exercise testing (CPX) were randomly performed in 258 HF patients [216 HF with reduced EF (HFrEF) and 42 HF preserved EF (HFpEF)], after which HRR was measured. HRR was defined as the difference between heart rate at peak exercise and 1 min following test termination. Patients were assessed for major cardiac events during a mean follow-up period of 22.8 ± 22.1 months. There were 50 major cardiac events during the tracking period. Univariate Cox regression analysis results identified HRR after both the 6MWT and CPX as a significant (P < 0.001) predictor of adverse events. Multivariate Cox regression analysis revealed that dichotomized HRR after the 6MWT and CPX was the strongest predictor of survival (χ2 61.1 and 53.8, respectively; P < 0.001), with LVEF (residual χ26.1, P < 0.05) adding significant prognostic value to the 6MWT model and ventilatory efficiency (the VE/VCO2 slope) (residual χ2 6.6, P < 0 .05) adding significant prognostic value to the CPX model.Conclusions HRR after the 6MWT is a powerful prognosticator that performs similarly to HRR after maximal exercise. If confirmed in subsequent studies, 6MWT HRR should replace 6MWT distance as the reference criterion 6MWT measure to consider when grading cardiovascular risk in HF patients
The 6 min walk test (6MWT) is a functional performance measure that has received substantial attention as a tool to examine the functional status of patients with heart and lung disease.[1–3] The distance ambulated during the 6MWT has been most studied, with a distance of 300 m being a threshold below which a patient with heart failure (HF) appears to have poorer prognosis.[2,3] A 6MWT distance of 300 m was also recently found to be a significant predictor of all-cause mortality in a multivariate model examining predictors of clinical outcome in elderly patients with advanced HF.[4] Even so, cardiopulmonary exercise testing (CPX) is considered the clinical gold standard for the functional assessment of patients with systolic HF.[5,6] A variety of CPX measurements have been found to provide substantial prognostic value in the assessment of patients with HF, and include peak VO2, the minute ventilation/carbon dioxide production (VE/VCO2) slope, and exercise oscillatory ventilation (EOV).An additional measurement which appears to have substantial prognostic value in patients with and without HF is the trajectory of heart rate (HR) decline after test termination, commonly referred to as heart rate recovery (HRR).[7–13] A low HRR value has consistently been observed to be a marker of increased mortality.[7–13] The rapid deceleration of the HR after exercise appears to reflect parasympathetic reactivation, providing a unique perspective regarding the health and function of the autonomic nervous system.[7–13] A HRR ≤12 beats at 1 min post-exercise has been proposed as a threshold to define an abnormal response,[12,13] which is supported by other investigators.[10,11]The clinical utility of HRR does not appear to be dependent on maximal exercise since two previous large studies administering symptom-limited exercise tests (terminating exercise at 85–90% of age-predicted peak HR) found that an abnormal HRR remained a prognostic index despite achieving less than age-predicted maximal HR values.[14,15] Because of previous findings, we believed it important to examine the prognostic utility of HRR after an accepted submaximal functional assessment such as the 6MWT, testing the hypothesis that it may become a valuable submaximal variable in the prognostic work-up of HF patients.