Recently, a large number of epidemiological studies have shown that heart rate is also a strong and independent predictor of cardiovascular events in a wide range of patients, including those with coronary artery disease (CAD) and postmyocardial infarction.2-4 Patients with a higher baseline heart rate have a higher risk of cardiovascular events and vice versa. This risk seems to become particularly evident with heart rate above 70 bpm.4,5 (Figure 2) Patients with a baseline heart rate above 70 have a significantly higher risk of all cardiovascular events as compared to those with heart rate below 70 bpm.6 Pure heart rate reduction reduces the risk of coronary events in CAD patients with heart rate above 70 bpm.5

HeartRate02Figure 2. Elevated HR (>70 bpm) is a predictor of cardiovascular
outcomes in the BEAUTIFUL placebo population.

Thus reducing resting heart rate and limiting the increase in heart rate are a very rational strategy to prevent ischemia and improve the cardiovascular prognosis in stable CAD patients.

HeartRate03Figure 3. Role of elevated heart rate in the pathophysiology of CAD.

References:

1. Andrews TC, Fenton T, Toyosaki N, et al. Subsets of ambulatory myocardial ischemia based on heart rate activity. Circadian distribution and response to antiischemic medication. The Angina and Silent Ischemia Study Group (ASIS). Circulation. 1993;88:92-100.
2. Fox K, Borer JS, Camm AJ, et al. Resting heart rate in cardiovascular disease. J Am Coll Cardiol 2007;50:823-830.
3. Kjekshus JK. Importance of heart rate in determining beta-blocker efficacy in acute and long-term acute myocardial infarction intervention trials. Am J Cardiol. 1986;57:43F-49F.
4. Diaz A, Bourassa MG, Guertin MC, et al. Long-term prognostic value of resting heart rate in patients with suspected or proven coronary artery disease. Eur Heart J. 2005;26:967-974.
5. Fox K, Ford I, Steg PG et al. Ivabradine for patients with stable coronary artery disease and left ventricular dysfunction (Beautiful): a randomized, double-blind, placebo-controlled trial. Lancet 2008, 372, 807–816.
6. Fox K, Ford I, Steg PG et al. Ivabradine for patients with stable coronary artery disease and left ventricular dysfunction (Beautiful): a randomized, double-blind, placebo-controlled trial. Lancet 2008; 372: 817–821.