Abstract
We thank Yayla et al 1 for their interest in our study, which reported that resting heart rate (HR) was a powerful and independent predictor of severity and complexity of coronary atherosclerosis as assessed by the SYNTAX score in patients with stable coronary artery disease. 2
As Yayla et al 1 mention, dosage and duration of use of HR-lowering drugs (eg, β-blockers and calcium channel blockers) can affect the resting HR. However, we did not provide detailed information about these medications, which is a limitation of our study.
We excluded patients with heart failure (ejection fraction <50%) or patients with any kind of arrhythmia. Therefore, there was no indication of digoxin or ivabradine use, and no participant was taking these drugs.
Our study was designed to determine the relationship between resting HR and SYNTAX score in patients with stable angina. We found a significant correlation between resting HR and SYNTAX score (r = .690, P < .001). 2 Recent evidence suggests an important role of HR in the pathophysiology of atherosclerosis. 3,4 Resting HR is influenced by the degree of sympathetic tone. Increased sympathetic tone causes several changes in vascular structures (eg, the coronary endothelium), and this contributes to atherosclerosis formation. 4,5 In our opinion, although HR can be decreased by drugs, increased sympathetic tone may not be affected. We need more studies to assess the therapeutic effects of lowering HR in patients with coronary atherosclerosis.