Resting Heart Rate and Cardiovascular Outcomes during Intensive and Standard Blood Pressure Reduction: An Analysis from SPRINT Trial

The association between elevated resting heart rate (RHR) as a cardiovascular risk factor and lowering of systolic blood pressure (SBP) to currently recommended values remain unknown. Systolic Blood Pressure Intervention Trial (SPRINT) data obtained from the NHLBI were used to describe the relationship between RHR and SBP reduction to <120 mmHg compared to SBP reduction to <140 mmHg. The composite clinical endpoint (CE) was defined as myocardial infarction, acute coronary syndrome, decompensation of heart failure, stroke, or cardiovascular death. Increased RHR was associated with a higher CE risk compared with low RHR in both treatment arms. A more potent increase of risk for CE was observed in subjects who were allocated to the SBP < 120 mmHg treatment goal. A similar effect of intensive and standard blood pressure (BP) reduction (p for interaction, 0.826) was observed in subjects with RHR in the 5th quintile (hazard ratio, 0.78, with 95% confidence interval (CI), 0.55–1.11) and in other quintiles of baseline RHR (hazard ratio, 0.75, with 95% CI, 0.62–0.90). Lower in-trial than baseline RHR was associated with reduced CE risk (hazard ratio, 0.80, with 95% CI, 0.66–0.98). We concluded that elevated RHR remains an essential risk factor independent of SBP reduction.