Association of blood pressure and heart rate response during exercise with cardiovascular events in the Heart and Soul Study

Background We sought to evaluate the association of blood pressure and heart rate response during exercise with myocardial infarction (MI), heart failure, stroke, transient ischemic attack (TIA) and death in ambulatory adults with coronary artery disease. Methods A study population of 937 patients with stable coronary artery disease underwent treadmill exercise stress testing and was followed for 5 years. Participants were divided into quartiles based on peak SBP change, peak SBP and heart rate. We used multivariable Cox proportional hazards models to evaluate the association of change in SBP and heart rate with subsequent cardiovascular events. Results The participants with SBP increases in the highest quartile had a decreased rate of hospitalization for heart failure [hazard ratio 0.38, 95% confidence interval (CI), 0.21-0.7; P= 0.002], MI (hazard ratio 0.3, 95% CI 0.15-0.58; P = 0.0004), stroke or TIA (hazard ratio 0.39, 95% CI 0.15-0.98 ; P = 0.04), and all cause mortality (hazard ratio 0.5, 95% CI 0.33-0.76; P=0.001). After adjusting for age, history of MI and HTN, use of β blockers, statins and calcium channel blockers, resting heart rate, and SBP, participants with SBP change in the highest quartile remained at lowest risk of MI (hazard ratio 0.31, 95% CI 0.15-0.66, P=0.002), hospitalization for heart failure (hazard ratio 0.46, 95% CI 0.22-0.97, P=0.04) and death (hazard ratio 0.52, 95% CI 0.32-0.86, P= 0.01). This association was largely explained by greater exercise capacity in those with the highest SBP change. Change in heart rate had a similar association with cardiovascular events. Conclusion In ambulatory patients with coronary artery disease, the group with the greatest blood pressure and heart rate increase had the lowest risk of MI, heart failure, stroke or TIA and death. These findings support the notion that a robust blood pressure response predicts favorable outcomes.