Heart rate: from risk marker to risk factor

Several risk factors for the development of coronary heart disease and related mortality have been identified to facilitate detection of patients at high risk and to guide prevention of the disease and its sequelae. This presentation will suggest that heart rate, easily measured clinically, is evolving from its demonstrated status as a risk marker of mortality and morbidity in various populations, to become a risk factor in patients with established coronary artery disease. Substantial epidemiological data support the predictive value of resting heart rate for total mortality and cardiovascular mortality. Indeed, this relationship was found in the general population and in hypertensive patients as well as in patients with clinically evident coronary artery disease (including those with stable angina and prior myocardial infarction). Several criteria commonly used to assess the validity of epidemiological associations (such as those involving blood cholesterol concentrations and development of coronary artery disease) have been applied to resting heart rate. The relationships between resting heart rate and the development of coronary artery disease, as well as all-cause and cardiovascular mortality, were found to be strong, graded and independent of other factors such as blood pressure and physical activity. The ongoing BEAUTIFUL and SHIFT trials will assess the therapeutic value of pure heart rate reduction in populations with coronary artery disease with and without heart failure (as well, in SHIFT, in patients with heart failure in the absence of coronary disease), thus providing the necessary evidence to support risk factor status for heart rate in this population.