Impact of Exercise-Based Cardiac Rehabilitation on the Mid-Term Outcomes of Patients After Acute Myocardial Infarction Treated With Current Acute-Phase Management and Optimal Medical Therapy

The proGnostic role of caRdiac rehAbilitation in patients with left ventriCular anEurysm formation after anterior myocardial infarction (the GRACE study): Study rationale and design of a prospective randomized controlled trial

Background

Cardiac rehabilitation (CR) is an essential intervention after acute myocardial infarction (MI). However, it is still unclear whether patients with left ventricular aneurysm (LVA) formation after anterior MI would benefit from CR programs. This clinical trial is designed to assess the role of CR in patients with LVA formation after anterior MI.

Trial design

The GRACE study is a single-center, single-blind, prospective, randomized controlled clinical trial in China. 100 subjects aged 18-75 years with LVA formation after anterior MI will be recruited and randomized 1:1 to the CR or control group. Both groups will receive standard drug treatment and routine health education according to the guidelines. Participants in the CR group will additionally receive tailored CR programs delivered over a period of 36 sessions. These participants will then be followed up for 1-year. The primary outcome is peak oxygen uptake measured by cardiopulmonary exercise testing after CR programs. The secondary outcomes are cardiac function and EuroQol 5-Dimension-3 Level index scores after CR program and 1-year and major adverse cardiac cerebrovascular events, a composite of cardiovascular mortality, non-fatal MI, non-fatal stroke, malignant arrhythmia or hospitalization for heart failure during the follow-up period.

Conclusions

This single-center, single-blind, prospective, randomized controlled clinical trial will determine whether CR improves physical capacity and clinical outcomes in patients with LVA formation after anterior MI.

Trial registration

Chinese Clinical Trial Registry ChiCTR2200058852. Registered on 18 April 2022.

Cardiac Structure and Cardiorespiratory Fitness in Young Male Japanese Rugby Athletes

Limited data are available on athlete's heart for rugby athletes. This study aimed to investigate cardiac structure and its relationship with cardiorespiratory fitness in young Japanese rugby athletes. A prospective cross-sectional study using echocardiography and cardiopulmonary exercise testing (CPET) was conducted on 114 male collegiate rugby players. There was a higher prevalence of increased left ventricular (LV), atrial, and aortic dimensions in the young athletes than that in previously published reports, whereas the wall thickness was within the normal range. Anthropometry and CPET analyses indicated that the forwards and backs presented muscular and endurance phenotypes, respectively. Indexed LV and aortic dimensions were significantly larger in the backs than in the forwards, and the dimensions significantly correlated with oxygen uptake measured by CPET. On the four-tiered classification for LV hypertrophy, abnormal LV geometry was found in 16% of the athletes. Notably, the resting systolic blood pressure was significantly higher in athletes with concentric abnormal geometry than in the other geometry groups, regardless of their field positions. Japanese young athletes may exhibit unique phenotypes of cardiac remodeling in association with their fitness characteristics. The four-tiered LV geometry classification potentially offers information regarding the subclinical cardiovascular risks of young athletes.

Efficacy of Exercise Rehabilitation in Patients with Atrial Fibrillation after Radiofrequency Ablation: A Meta-Analysis of Randomized Controlled Trials

Background and Aims

Radiofrequency ablation is a commonly used treatment for paroxysmal atrial fibrillation (AF), but postoperative rehabilitation exercises are needed to reverse left ventricular structural and functional abnormalities. This meta-analysis aimed to evaluate the intervention effect of exercise training in patients with AF after radiofrequency ablation.

Methods

A systematic literature search was conducted to identify articles in PubMed, MEDLINE, EMBASE, and the Cochrane Library from January 1, 2010 to December 1, 2021. The mean difference with 95% CI was pooled for continuous variables. We used Review Manager 5.3 for the standard meta-analysis. This study followed the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

Results

Ten randomized controlled trials (RCTs) were included, with a total of 892 patients with AF. The quality of one study was grade A, and the rest were grade B. The results of the meta-analysis showed that the improvement of 6 min walking distance (MD = 34.42, 95% CI: 3.20 to 65.63, P=0.03), peak oxygen uptake (MD = 1.96, 95% CI: 1.14 to 2.78, P < 0.001), left ventricular ejection fraction (LVEF) (MD = 0.09, 95% CI:0.01-0.17, P=0.02), resting heart rate (MD = -4.50, 95% CI: -8.85 to -0.14, P=0.04), and physical component summary (PCS) (MD = 3.00, 95% CI: 0.46 to 5.54, P=0.02) in the experimental group was significantly better than that of the control group, and the difference was statistically significant.

Conclusion

Exercise training can improve the level of exercise endurance and cardiac function in patients. However, the results were limited by the quantity and quality of the studies. Large samples and high-quality studies are still needed to verify its long-term efficacy.

Mechanisms of Exercise Capacity Improvement after Cardiac Rehabilitation Following Myocardial Infarction Assessed with Combined Stress Echocardiography and Cardiopulmonary Exercise Testing

Cardiac rehabilitation (CR) is indicated in all patients after acute myocardial infarction (AMI) to improve prognosis and exercise capacity (EC). Previous studies reported that up to a third of patients did not improve their EC after CR (non-responders). Our aim was to assess the cardiac and peripheral mechanisms of EC improvement after CR using combined exercise echocardiography and cardiopulmonary exercise testing (CPET-SE). The responders included patients with an improved EC assessed as a rise in peak oxygen uptake (VO₂) ≥ 1 mL/kg/min. Peripheral oxygen extraction was calculated as arteriovenous oxygen difference (A-VO₂Diff). Out of 41 patients (67% male, mean age 57.5 ± 10 years) after AMI with left ventricular ejection fraction (LVEF) ≥ 40%, 73% improved their EC. In responders, peak VO₂ improved by 27% from 17.9 ± 5.2 mL/kg/min to 22.7 ± 5.1 mL/kg/min, p < 0.001, while non-responders had a non-significant 5% decrease in peak VO₂. In the responder group, the peak exercise heart rate, early diastolic myocardial velocity at peak exercise, LVEF at rest and at peak exercise, and A-VO₂Diff at peak exercise increased, the minute ventilation to carbon dioxide production slope decreased, but the stroke volume and cardiac index were unchanged after CR. Non-responders had no changes in assessed parameters. EC improvement after CR of patients with preserved LVEF after AMI is associated with an increased heart rate response and better peripheral oxygen extraction during exercise.