Purpose: Heart rate recovery (HRR) immediately after peak exercise has utility as a predictor of all-cause mortality. However, a prognostic role for HRR has not been specifically evaluated in patients with type 2 diabetes mellitus (T2DM), nor has an association between HRR and cardiovascular (CV) events been documented. This study investigated whether HRR is predictive of all-cause mortality, CV mortality, and CV events in asymptomatic patients with T2DM.
Methods: HRR in subjects with T2DM was obtained via chart review of peak exercise treadmill tests (N = 890) performed at entry into the Appropriate Blood Pressure Control in Diabetes trial. Survival analysis was used to test the association of 1- and 2-min HRR with all-cause mortality, CV mortality, and CV events during the follow-up period.
Results: Subjects were followed for a median of 5.0 yr. All-cause mortality and CV events were significantly greater among the lowest quintile (< 12 bpm) of 1-min HRR compared with the fourth (23-28 bpm) quintile. Similarly all-cause mortality and CV events were significantly greater among the lowest quintile (< 28 bpm) of 2-min HRR compared with the third quintile (37-42 bpm) quintile. After adjustment for traditional cardiac risk factors, attenuated 1- and 2-min HRR remained significantly associated with increased risk of CV events as compared with those without attenuation.
Conclusions: HRR provides information beyond traditional CV risk factors that could aid in the clinical risk stratification of patients with T2DM. The results suggest that HRR results should be incorporated into standard diagnostic treadmill testing reports and target those patients with T2DM and attenuated HRR who can benefit from directed therapies.