The effect of beta‐blockade therapy on the response to exercise training in postmyocardial infarction patients

Abstract

Summary: Cardiac rehabilitation after a myocardial infarction has been shown to improve exercise capacity. Beta blockade has been shown to be effective in treating angina and reducing mortality, but studies are controversial as to whether beta-blockade therapy attenuates the effects of training. We attempted to study the effects of beta blockade (metoprolol) on the response to training in patients enrolled in a cardiac rehabilitation program after an uncomplicated myocardial inf'arction. We studied 27 patients with a recent uncomplicated myocardial infarction who were subdivided in two groups: Group 1 ( I3 patients) not taking a beta blocker, and Group 2 ( 14 patients) taking metoprolol (mean 142 2 57 mg daily). All patients underwent a maximal cardiopulmonary exercise test before and after a 3-month training program. The training intensity was designed to approximate the ventilatory threshold. Results showed an increase in peak VO? in both Group 1 (27%1, p<0.01)andGroup2(33%, p<O.OOI),andan increase in VO2 at the ventilatory threshold (39% in Group 1 and 28% in Group 2, p < 0.01). The mean changes in exercise capacity were not different between groups. It was concluded that metoprolol did not influence the beneficial effects ofa cardiac rehabilitation program in postmyocardial infarction patients.

Cardiopulmonary exercise testing and efficacy of percutaneous coronary intervention: a substudy of the ORBITA trial

“…Similarly, antianginals such beta-blockers (despite a blunted heart rate response) and ranolazine have shown to improve peak VO 2 through enhanced microcirculatory and endothelial function. 53–55 Hence, the effect of intensive guideline-directed medical therapy at pre-randomization may have also reduced the incremental effect size from PCI. Cardiopulmonary exercise testing was not performed at enrolment, therefore we do not know the effect size of medical therapy alone on VGE in patients with stable CAD.…”

A practical clinical approach to utilize cardiopulmonary exercise testing in the evaluation and management of coronary artery disease

“…Rosiglitazone improves endothelial function and peak VO 2 in people with diabetes after 4 months of therapy [ 45 ]. Although beta-blockers blunt the HR response to physical exertion, previous research has found a significant increase in peak VO 2 still occurs in post MI and heart failure patients who participate in an exercise training program [ 46 ]. Metformin improves ventilatory efficiency in nondiabetic heart failure patients with insulin resistance [ 47 ].…”

Guidelines for Rehabilitation in Patients With Cardiovascular Disease (JCS 2012)

“…59 Although there is discussion on the effect of β-blocker therapy on the response to exercise training after MI, mean changes in exercise capacity were not significantly different between post-MI patients receiving and not receiving β-blockers during cardiac rehabilitation program. 113 Also, after AMI, the effects of exercise training and β-blockers on heart rate variability are not redundant. 114 Although the benefits of exercise training in post-MI patients have been demonstrated, the use of cardiac rehabilitation is quite limited, which contrasts with the widespread use of PCI in the treatment of MI.…”