Background: regional or global impairment of left ventricular (LV) systolic or diastolic function leading to increased LV wall stress results in increased circulating levels of N-terminal pro-brain natriuretic peptide (NT-pro-BNP).
Objective: this study aims at evaluating the effect of exercise training (ET) on NT-pro-BNP plasma levels in older patients recovering from acute myocardial infarction (AMI).
Design: prospective randomised study.
Setting: Academic Medical Centre.
Subjects: forty older patients (33 males and 7 females) who experienced AMI.
Methods: patients were randomised into two groups, each composed of 20 patients: Group A were enrolled in a 3-month exercise-based cardiac rehabilitation (CR) programme and Group B were discharged home with generic instructions to continue physical activity. NT-pro-BNP, cardiopulmonary and Doppler-echocardiographic parameters were measured at baseline and at 3-month follow-up.
Results: in Group A, ET reduced NT-pro-BNP levels (from 1446 +/- 475 to 435 +/- 251 pg/ml, P<0.001) and increased maximal exercise parameters; there was also an inverse correlation between changes in NT-pro-BNP levels and in VO(2peak) (r = -0.67, P<0.01), E-wave (r = -0.42, P<0.01) and E/A ratio (r = -0.60, P<0.01). In Group B, after 3 months, no changes were observed in NT-pro-BNP levels, exercise and echocardiographic parameters. LV volumes and left ventricular ejection fraction (LVEF) were unchanged after 3 months in both groups.
Conclusions: three months ET in older patients after AMI was associated with a reduction in NT-pro-BNP levels and an overall improvement of exercise capacity, without negative LV remodelling and with improvement in early LV filling. Further investigation is required to evaluate whether in these patients the reduction of NT-pro-BNP levels at 3 months could be useful as a surrogate marker of favourable LV remodelling at a later follow-up.