Aerobic exercise, but not isometric handgrip exercise, improves endothelial function and arterial stiffness in patients with myocardial infarction undergoing coronary intervention: a randomized pilot study.

Background: Aerobic exercise improves endothelial function and arterial stiffness after myocardial infarction (MI), but the effects of isometric exercise on cardiovascular parameters are still uncertain. We aimed to assess the effects of one session of aerobic or isometric exercise on flow-mediated dilation (FMD) and pulse wave velocity (PWV) in post-MI volunteers undergoing percutaneous coronary intervention (PCI).

Methods: Twenty post-MI patients undergoing PCI were randomized to aerobic (AE, n = 10) or isometric (IE, n = 10) exercise groups. We evaluated cardiac structure and function (echocardiographic); carotid plaque presence (ultrasound). FMD and PWV were measured 10 min before and 10 min after the intervention: a single session of moderate-intensity AE (30 min; ratings 12-14 on Borg's scale or 50-60% HRreserve) or handgrip IE (four two-minute bilateral contractions; 30% maximal voluntary contraction; 1-min rest). Generalized estimating equations (Bonferroni post-hoc) was used to assess differences (p ≤ 0.050).

Results: FMD improved only in the AE group (Δ = 4.9%; p = 0.034), with no difference between groups after exercise. Even after adjustment (for baseline brachial artery diameter) the effectiveness of AE remained (p = 0.025) with no change in the IE group. PWV was slightly reduced from baseline in the AE group (Δ = 0.61 m/s; p = 0.044), and no difference when compared to the IE group. Peripheral vascular resistance decreased in AE versus IE (p = 0.050) and from baseline (p = 0.014).

Conclusions: Vascular measurements (FMD and PWV) improved after a single session of AE. There are apparently no benefits following a session of IE.

Trial Registration: http://www.clinicaltrials.gov and ID number NCT04000893.