Ratio of early mitral inflow peak velocity to flow propagation velocity predicts training effects of cardiac rehabilitation in patients after acute myocardial infarction
Cheng-Chih Chung, Wei-Chun Huang, Kuan-Rau Chiou, Ko-Long Lin, Feng-Yu Kuo, Chin-Chang Cheng, Shih-Hung Hsiao, Chun-Peng Liu
Objective: To use the ratio of early mitral inflow peak velocity (E) to mitral flow propagation velocity (FPV) measured in the early phase of myocardial infarction (early phase E/FPV) to evaluate the training effects of 8 weeks’ cardiopulmonary rehabilitation in patients post-myocardial infarction.
Design: Single-blinded, randomized control trial.
Participants: Eighty-seven patients with acute myocardial infarction who had undergone primary coronary intervention.
Methods: Participants were enrolled randomly to either the cardiac rehabilitation or the control group. The rehabilitation group followed an 8-week supervised rehabilitation programme. All patients completed exercise testing and echo-
cardiography at both the beginning and at 8-week follow-up.
Results: The value of E/FPV was significantly reduced at 8-week follow-up in the rehabilitation group (p = 0.005). After cardiac rehabilitation, the increase in peak VO2 (p = 0.002) and cardiac clinical outcome (composition of mortality, cardiac readmission rate, and revascularization rate) (p = 0.001) were significantly greater in patients with an early phase E/FPV < 1.5 than in patients with early phase E/FPV ≥ 1.5. There were no significant differences in the increase in peak V O2 and cardiac clinical outcome in patients with early phase E/FPV ≥ 1.5.
Conclusion: Early phase E/FPV < 1.5 predicts more beneficial effects of cardiac rehabilitation in post-acute myocardial infarction patients who have undergone primary coronary intervention.