Ambulatory heart rate parameters predict death in hypertensive patients

Ambulatory blood pressure monitoring (ABPM) provides significant data on heart rate (HR) parameters, which can help predict the risk of mortality in patients with hypertension, a study has found.

ABPM recordings from 56,901 patients with complete HR measures from the Spanish Blood Pressure Monitoring Registry were evaluated, with a median follow-up of 5.1 years.

The investigators assessed the association of office HR, mean 24-h HR, mean day HR, mean night HR as well as day–night HR differences, morning mean HR, morning HR surge, and night peak HR with all-cause, cardiovascular, and noncardiovascular mortality. They examined the data using Cox regression analysis, analysis of variance, and chi-square test.

The Spanish ABPM registry recorded data in 223 primary care centres in Spain from 2004 until 31 December 2014 at the end of recruitment. Office HR was higher by 3.5 bpm than mean 24-h HR, office mean HR by 10.4 bpm than mean night HR, and mean day HR by 9.3 bpm than mean night HR. No significant difference was noted between office and mean day HR.

Office mean, 24-h day, and night HR >90 bpm correlated with a higher risk of all-cause and noncardivoascular death, while mean night HR was the only predictor of cardiovascular death.

All-cause death was strongly associated with mean night HR (hazard ratio, 3.80, 95 percent confidence interval [CI], 2.87–5.03), mean 24-h HR (hazard ratio, 2.85, 95 percent CI, 2.30–3.54), and mean day HR (hazard ratio, 2.22, 95 percent CI, 1.83–2.70).

Day–night dipping >8 bpm led to a 20-percent decreased risk of all-cause, cardiovascular, and noncardiovascular death. Results were robust after adjusting for relevant risk indicators.