A 2016 meta-analysis in the Canadian Medical Association Journal found that a higher resting heart rate is linked to a higher risk of death from all causes and cardiovascular disease. Specifically, for every 10 beats per minute increase in resting heart rate, there was a 9% higher risk of all-cause mortality and an 8% higher risk of cardiovascular mortality. People whose resting heart rate was 80 beats per minute or higher had a 45% higher risk for all-cause mortality and a 33% higher risk for cardiovascular death.
A high resting heart rate is also linked to other diseases, according to a 2018 article in Heart. After considering factors like blood pressure and existing medical conditions, the researchers found that a higher resting heart rate was linked to an increased risk of death, not just from heart disease but also from various types of cancer such as breast, colorectal, kidney, and lung cancer.
Keeping a low resting heart rate throughout your life is also good for your health. A 2019 article in Open Heart followed men for 21 years to see how their resting heart rates had changed. The men whose resting heart rate remained stable for those years had a 44% lower risk of cardiovascular disease compared to those whose resting heart rate increased.