Pulse rate may predict risk of death due to heart disease: Study

By Dr. Ananya Mandal, MDDec 27 2011

While cholesterol levels, blood pressure, blood glucose levels and weight have been used to measure the risk of death due to heart diseases till now, a new parameter has emerged – the pulse rate.

Javaid Nauman and colleagues analyzed data from nearly 30,000 Norwegian adults without known cardiovascular disease who had their RHR (resting heart rate) measured at baseline and at 10 years. The population-based group consisted of 13,499 men and 15,826 women. They found that those whose resting heart rates increased over time were more likely to die from heart disease. The participants were healthy, with no history of heart conditions, and agreed to have their resting heart rates measured twice, 10 years apart, in 1984-86 and again in 1995-97.

During an average of 12 years of follow-up, a total of 3,038 people died. Among all deaths, 975 were caused by cardiovascular disease and 388 were due to IHD (ischemic heart disease). Results showed that those whose resting pulse crept from under 70 beats per minute at the first reading to more than 85 beats per minute at the second measurement were twice as likely to die over a 12-year follow-up, compared with people resting heart rate remained below 70 beats. People who started out with pulse rates between 70 and 85 beats per minute were also at risk of heart-related death; if their heart rates rose beyond 85 beats per minute by the second reading, they had an 80% increased risk of dying from heart disease, compared with people whose heart rates remained stable.

The opposite effect emerged in people whose heart rates dropped over time: those whose resting heart rate started out at 70 to 85 beats per minute and fell to less than 70 beats at the second reading were 40% less likely to die of heart disease than those who maintained their pulse rates.

Researchers explain that pulse rate is affected by various factors like weight, blood pressure, some medicines, smoking status, posture – standing or sitting etc. Experts say healthy adults can have pulse rates ranging from 60 to 100 beats per minute. Elite athletes typically have lower heart rates, around 40 beats per minute because of their better heart fitness.

The study is the first to detail how changes in resting heart rate over time may affect risk of death from heart disease. Because the resting pulse is relatively easy to measure, the authors say it could be a good way to identify people who might be at greater risk of heart problems, and help them lower their readings by improving diet and increasing exercise.

The study was published in the Journal of American Medical Association on Dec 21^st.

“As expected from the good general health of the study participants, the observed moderate-to-strong increases in relative risk corresponded to small risk increases in absolute terms. However, it is not clear to what extent we can extrapolate our findings to less healthy individuals in whom the underlying risk is likely to be higher,” the authors note.

“Our findings provide further support for the hypothesis that RHR may be an important prognostic marker for IHD and total mortality. Information on RHR and its time-related changes are easy to obtain and follow-up and may be useful in identifying asymptomatic people who could benefit from measures of primary prevention, but further study in this area is warranted.”

“Resting heart rate is one of the simplest measures in medicine and everyone can do that by themselves at home. From cross-sectional studies, it is known that a person's resting heart rate is related to the relative risk of premature cardiovascular disease and death. However, it has not, before now, been associated with an increased risk of premature cardiovascular death,” said study senior author Ulrik Wisloff, director of the K.G. Jebsen Center of Exercise in Medicine in Trondheim, Norway. “Our observations suggest that resting heart rate may be an important prognostic marker for ischemic heart disease and total mortality,” said Wisloff, who added that changes in resting heart rate may signal the need for lifestyle changes.