Changes in heart rate over time correlate with cardiovascular risk

Increases in heart rate over time signal a higher risk of cardiovascular disease and death, supporting the use of serial monitoring in clinical practice, researchers reported in JAMA Cardiology.

Ali Vazir, MBBS, PhD, and colleagues studied 15,680 participants from the Atherosclerosis Risk in Communities cohort. Heart rate was measured at baseline and during three follow-up visits from 1987 to 1998, with a median interval of three years between visits. Participants were then tracked through 2014, equaling 28 years of follow-up from baseline.

After adjusting for risk factors and medication use, each increase of five beats per minute (BPM) was associated with a 12 percent increased risk of all-cause mortality and a 13 percent higher risk of incident heart failure. Those BPM changes were also linked to higher risks of cardiovascular death (13 percent), noncardiovascular death (12 percent), myocardial infarction (9 percent), stroke (6 percent) and cancer death (8 percent).

The researchers noted “near linear” relationships for all-cause mortality and heart failure, in which any increase in heart rate above a certain level was associated with elevated risk and drops in heart rate were associated with lesser risk.

“Our study confirms that temporal changes in HR are of prognostic importance in a community population,” Vazir et al. wrote. “Temporal increases in HR over time may reflect increased sympathetic activity through the development of subclinical underlying CV (cardiovascular) or non-CV disease, including cancers or reduced fitness. In contrast, a drop in HR may reflect improving cardiac function, physical fitness, and lower sympathetic tone.”

Vazir and colleagues also found patients’ most recent heart rate was more predictive of outcomes than baseline measurements. When only considering the most recent heart rate, every five-BPM increase was linked to a 14 percent higher risk of all-cause mortality and a 17 percent higher risk of incident heart failure.

“Our observation suggests that monitoring of HR over time as a biomarker of health status in the clinic setting or remotely may be useful in identifying participants at greatest risk of CV, such as incident HF, or non-CV events, such as chronic obstructive pulmonary disease, infections, and cancers,” the authors wrote. “Heart rate is of importance, especially as it is potentially a modifiable risk factor in selected populations and these individuals could be considered for interventions that might improve their disease trajectory. Whether remote monitoring devices that can assess HR more continuously might improve risk prediction in the community will need further study.”

Notably, the association between heart rate changes and outcomes disappeared for patients using beta-blockers, which slow heart rate. Vazir and coauthors said the reasons for this are unclear, and they weren’t able to verify dosing levels of the heart rate-limiting drugs for analysis.