Healthy people still need to stay fit to avoid a heart attack, study finds

ENR January 23, 2019

The HUNT Fitness Study investigated whether cardiorespiratory fitness is associated with the risk of coronary heart disease in healthy, low-risk men and women.

Coronary heart disease (CHD) is caused by the narrowing of the coronary arteries which supply oxygen and blood to the heart and can lead to a heart attack. While recent advances in therapeutic strategies—including percutaneous coronary interventions (PCI) and optimized medical treatment—have led to reduced CHD-associated morbidity and mortality, the incidence of CHD remains high. The development of early risk detection and prevention strategies will help to decrease the overall prevalence of CHD and further reduce CHD-associated morbidity and mortality.

What is cardiorespiratory fitness?

Cardiorespiratory fitness is a measure of the circulatory and respiratory system’s ability to supply oxygen to the muscles. It has been associated with cardiovascular and all-cause mortality. Recently, the American Heart Association recommended that cardiorespiratory fitness should be routinely monitored in order to improve risk classification and optimize prevention of CHD. These recommendations, however, are based on a limited number of studies with small cohort sizes that included few women. It is also unclear whether these recommendations can effectively predict CHD risk in a healthy population.

The HUNT Fitness Study

In the recent HUNT Fitness Study, Letnes and colleagues investigated the association between VO_2peak , a gold standard measure of cardiorespiratory fitness, with fatal and non-fatal coronary heart disease events or coronary revascularization. A total of 4,527 healthy participants were recruited to the study, 51% of which were women. They published their results in European Heart Journal.

Over the study period, 147 participants were either diagnosed with or died from CHD or had to undergo coronary revascularization surgery. When considering men and women together, the authors found that higher VO_2peak (better cardiorespiratory fitness) was associated with a lower risk of CHD following adjustment for confounding factors including sex, smoking status, alcohol use, and family history of cardiovascular disease. When men and women participants were analyzed separately, the same association between VO_2peak and CHD risk was observed.

Better cardiorespiratory fitness is associated with lower risk of coronary heart disease

In summary, the authors found that VO_2peak was inversely related to the risk of CHD in both men and women. This means that better cardiorespiratory fitness was associated with a lower risk of CHD. These findings suggest that including VO_2peak in risk assessment of CHD may allow patients to appreciate the warning signs of disease at an earlier stage. This could, in turn, provide patients more time to make healthy life changes that decrease their risk of heart disease.

Although more research is warranted to further validate these findings, incorporating VO_2peak in risk assessment can ultimately help identify high-risk patients and thus allow these individuals to adjust their life accordingly.

Written by Haisam Shah, BSc

Reference: Letnes, J. M., Dalen, H., Vesterbekkmo, E. K., Wisløff, U., & Nes, B. M. (2018). Peak oxygen uptake and incident coronary heart disease in a healthy population: the HUNT Fitness Study. European Heart Journal.