Study Reveals How Resting Heart Rate Affects Stroke Risk Over Decades

A major study has uncovered a clear link between resting heart rate and stroke risk. Researchers tracked nearly half a million people for over a decade, revealing that both very high and very low heart rates can significantly increase the chances of a stroke. The study, published using data from the UK Biobank, followed 460,000 participants for around 14 years. During this time, 12,290 strokes were recorded among the group. Findings showed that those with resting heart rates below 50 beats per minute (bpm) faced a 25% higher risk of stroke compared to others.

A very low heart rate, known as bradycardia, can reduce blood flow to the brain. This reduction may raise the likelihood of an ischemic stroke, where a clot blocks blood supply. On the opposite end, participants with resting heart rates above 90 bpm were 45% more likely to experience a stroke. The risks remained even after accounting for well-known factors like high blood pressure, diabetes, and atrial fibrillation. Very high heart rates were connected to both ischemic and hemorrhagic strokes—the latter caused by bleeding in the brain. The safest range appeared to be between 60 and 69 bpm, where stroke risk was lowest. Researchers stressed that resting heart rate is a simple, widely available measure. They suggested it should play a bigger role in assessing cardiovascular risks, alongside traditional indicators.

The findings highlight the importance of monitoring resting heart rate as part of stroke prevention. Both extremely high and low rates were tied to greater risks, even after adjusting for other health conditions. This could lead to more personalised approaches in managing stroke risk in the future.