A comparative study of the double product index before and after cardiac rehabilitation in patients undergoing coronary artery bypass grafting

Background and Purpose: Cardiovascular disease, especially coronary artery disease, is the most common cause of death in the world. Cardiac rehabilitation (CR) is provided to improve the effectiveness and decrease the side effects of coronary artery bypass grafting (CABG). This study was performed in 2014 in the CR center of Ekbatan hospital, Hamadan, Iran, to compare the double product (DP) index before and after CR in patients undergoing CABG. Materials and Methods: In this study, 100 patients visiting the center, who underwent CABG 2 months earlier, were studied. The exercise tolerance tests (ETTs) were conducted before and after the rehabilitation sessions for everyone, and the maximum heart rate and systolic blood pressure of them during the ETT were collected at their peak level. Results: In general, the mean of the DP index showed a significant increase after rehabilitation compared to before it ( P = 0.05). Furthermore, the mean comparison of this index based on the independent study variables showed that the increase of the mean of the DP index after rehabilitation in men in both the age groups of below and above 60-year-old, in nondiabetic patients, in people with high blood lipids, people with normal blood lipids, patients with moderate degree of left ventricular dysfunction (EF = 30–44), people with relatively normal left ventricular function, smokers and nonsmokers, as well as individuals with no history of high blood pressure, was significantly different. Conclusion: The results of this study showed that the mean of the DP index which is a quantitative criterion for the assessment of cardiac function, significantly increased after 12 rehabilitation sessions in patients who underwent CABG.