Rest may not be best soon after MI
MedWire News: Researchers report that contrary to popular belief, early exercise rather than rest provides myocardial infarction (MI) patients with the best heart performance outcomes.
"In the past, patients in Canada and the US have been told to wait for 1 month before beginning their exercise treatment and this treatment typically goes on for about 3 months," said co-researcher Alexander Clark, from University of Alberta in Edmonton, Canada.
However the results from their 12-study meta-analysis indicate that "the largest changes in left ventricular (LV) modeling were obtained when [exercise] programs began after around 1-week post-MI hospital discharge and lasted for 6 months," says the team, led by Mark Haykowsky, also from the University of Alberta.
Of note, the exercise programs undertaken by the study patients were aerobic in nature and performed in a group setting with the aim of building up exercise capacity.
Analysis of measures of heart function, namely ejection fraction, end systolic volumes, and end diastolic volumes, showed that improvement in heart function reduced as time between MI and starting an exercise program increased.
Furthermore, a positive relationship between the duration of the program and extent of improvement in heart function was observed by the team. "For every week that a patient delayed his or her exercise treatment, he or she would have to train for the equivalent of 1 month longer to get similar benefits," explained Clark.
He added: "Our findings suggest that at least 6 months of exercise is the most beneficial."
Haykowsky et al highlight that they found no evidence of harm associated with early exercise training.
Nonetheless, they call for "future high-quality randomized controlled trials of exercise intervention early post-MI on LV modelling."
The study findings are published in the open access journal Trials.
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By Lauretta Ihonor