Researchers in Switzerland concluded that any type of exercise helped improve blood vessel function in patients who had recently suffered a heart attack (acute myocardial infarction), but the benefits disappeared within one month of stopping, suggesting that exercise helps you recover from a heart attack but only if you keep it up.
The study was the work of scientists at the Cardiac Rehabilitation Center, Clinique Valmont-Genolier in Glion-sur-Montreux and the University of Lausanne and was published online before print on March 16 in the Circulation, a Journal of the American Heart Association.
The authors wrote that we already know that exercise benefits patients with coronary artery disease, but there is little evidence on which types of exercise have the most impact.
In this prospective study, Dr Margherita Vona of Clinique Valmont-Genolie and colleagues evaluated the effect of different types of exercise training on endothelial function (how well the blood flows through blood vessels) in 209 patients who had recently had their first acute myocardial infarction (MI, or heart attack).
The participants had all been referred for cardiac rehabilitation after MI between March 2003, and March 2005.
The researchers measured the participants’ endothelial function (flow-mediated dilation) before and after 4 weeks of different types of exercise training and then after 1 month of no training.
Each participant was randomly assigned to one of four groups: (1) aerobic exercise training, (2) resistance training, (3) resistance plus aerobic training, and (4) no training.
The results showed that:
- Over the four weeks of exercise, flow-mediated dilation significantly improved in the three exercise groups (1), (2) and (3), and it also improved, but to a much lesser extent, in group (4), the non exercise group.
- At the start of the 4 week exercise period the flow-mediated dilation was about 4 per cent in all four groups, and at the end of the 4 weeks it went up to about 10 per cent in the three exercise groups but only to 5 per cent in the non exercise group.
- Another measure of blood vessel function, the von Willebrand factor went down by 16 per cent in the three exercise groups but remained unchanged in the non exercise group over the 4 week exercise period. (Lower von Willebrand factor means the blood is less likely to clot).
- After 1 month of no exercise, all the flow-mediated dilation measures returned to what they were before the exercise training started (baseline).
Vona and colleagues concluded that:
“In patients with recent acute myocardial infarction, ET was associated with improved endothelial function independently of the type of training, but this effect disappeared after 1 month of detraining.”
In a press statement reported by MedPage Today, Vona said these findings should give patients an additional reason to:
“Carry out several types of physical activity to avoid exercise boredom and promote better long-term adherence to exercise programs.”
Vona said it was important to keep exercising in the longer term.
Speculating on how exercise might have this beneficial effect, the researchers said it could be the fact it increases shear stress, which stimulates the release of nitric oxide and increases antioxidant activity.
“Effects of Different Types of Exercise Training Followed by Detraining on Endothelium-Dependent Dilation in Patients With Recent Myocardial Infarction.”
M. Vona, G. M. Codeluppi, T. Iannino, E. Ferrari, J. Bogousslavsky, and L. K. von Segesser.
Circulation Published online before print March 16, 2009.
doi:10.1161/CIRCULATIONAHA.108.821736
Sources: Journal Abstract, MedPage Today.
Written by: Catharine Paddock, PhD