New research indicates that adults exhibiting unusual patterns in their resting heart rate as they age are at an increased risk of developing heart failure or experiencing mortality from any cause when compared to individuals whose heart rates follow a typical trajectory. The study unveiled that participants whose heart rates consistently rose over a 25-year period—regardless of whether the increase was minor or substantial—faced a higher likelihood of fatalities or heart failure than those whose resting heart rates either stabilized or slightly decreased.
These findings were presented at the American Heart Association’s Scientific Sessions in Chicago earlier this month but remain preliminary until they are published in an academic journal that has undergone peer review. Dr. Kunihiro Matsushita, the study’s lead investigator and a professor at Johns Hopkins School of Medicine as well as the Bloomberg School of Public Health, expressed surprise that nearly 90% of the participants displayed a stable or slightly declining heart rate trajectory. He initially expected more variability among the participants.
“This suggests that most people maintain a well-controlled resting heart rate,” Dr. Matsushita noted. However, he added that more than 10% of individuals did not adhere to this typical pattern, prompting inquiries into the underlying reasons for these atypical heart rate changes and their link to cardiovascular health challenges, as pointed out by lead researcher Ning Meng, who works in the division of rheumatology at the Johns Hopkins School of Medicine. Meng emphasized the need for further exploration into these mechanisms.
Resting heart rate, which is essentially the number of heartbeats per minute while an individual is at rest, usually ranges from 60 to 100 beats per minute for most adults. Individuals who engage in regular physical activity typically enjoy lower resting heart rates compared to their less active counterparts.
The researchers scrutinized health data from 5,794 participants in the Atherosclerosis Risk in Communities (ARIC) study to chart resting heart rate patterns over a period of 25 years. They identified four distinct heart rate trajectories. Notably, over 88% of the participants demonstrated either stable or slightly declining resting heart rates throughout the study duration. The remaining individuals exhibited three atypical patterns: approximately 9% experienced a steady and then a slight increase in heart rate with age, 2% showed fluctuating heart rates, and about half a percentage point underwent a steady and then a sharp increase in resting heart rates.
The average age of participants when the first heart rate measurements were taken was 52 years, while the average age at the last measurement was 76 years. Additional demographic factors indicated that individuals who smoked, those with a history of heart failure, obesity, or lower levels of education were more prone to exhibit these atypical heart rate patterns. After adjusting for various cardiovascular risk factors, participants whose resting heart rates increased—whether slightly or markedly—were found to be 65% more susceptible to developing heart failure and 69% more likely to die from any cause when compared to those whose heart rates had decreased slightly.
Dr. Meagan Wasfy, a cardiologist at Massachusetts General Hospital and an assistant professor at Harvard Medical School, noted the growing trend of individuals monitoring their heart rates more regularly, thanks to the availability of wearable technology. She commented on the significance of understanding the implications of heart rate changes over time to identify those at potential risk for negative health outcomes.
As researchers look to understand whether treatment should target heart rate management, the immediate message for the public is clear. Wasfy urges those who experience notable changes in their resting heart rates, especially when accompanied by other symptoms, to consult a healthcare professional. The pursuit of knowledge regarding the causes and implications of atypical heart rate patterns continues, as researchers aim to improve cardiovascular health outcomes.