Author + information
- Published online May 6, 2019.
- Sylvain Grall, MD,
- Romain Bouteau, MD,
- Jean-François Hamel, MD, PhD,
- Gabriel Garcia, MD,
- Hermeland Delagarde, MD,
- Serge Willoteaux, MD, PhD,
- Valérie Dubus, MD,
- Fabrice Prunier, MD, PhD,
- Alain Furber, MD, PhD and
- Loïc Bière, MD, PhD∗ ()
- ↵∗Institut MitoVasc, 3 rue Roger Amsler, 49100 Angers, France
Cardiac rehabilitation (CR) combines therapeutic education with physical training and is recognized to reduce mortality rates by approximately 22% following myocardial infarction (MI) (1). Despite its broad acceptance, some studies have reported that CR may be harmful, in terms of left ventricular remodeling (LVR), to patients with depressed LV function (2).
The aim of this study was to determine the prevalence of and the correlations associated with post-MI LVR in a real-life cohort of patients who underwent CR.
A total of 246 patients with a first ST-segment elevation myocardial infarction (STEMI) and successful revascularization in the 12 h after symptom onset were included in a prospective cohort (French governmental hospital-based clinical research program, [PHRC] No. 2006/0070). They underwent cardiac magnetic resonance (CMR) at baseline, which was 6 days after MI (interquartile range [IQR]: 4 to 9 days), and at 3 and 12 months. The imaging protocol was standard and included cardiac function and late gadolinium enhancement imaging.
Patients decided whether they wished to participate (n = 80) in the CR program once they received information from their referring physician.
CR began 65 days (IQR: 51 to 85 days) after MI and lasted for 3 weeks. Patients performed continuous aerobic physical training at ventilatory threshold, 5 days a week. Each session was 45 min, starting with a 5-min warm-up and ending with a 5-min cool down.
Because there is currently no categorical definition for LVR (3), we considered LVR to be the linear change in LV volumes. We carried out 3 linear mixed models for assessing the determinants of left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), and left ventricular end-systolic volume (LVESV) over time, with the baseline timepoint considered as the time reference. All tests were performed with a type I error set at 0.05. Analyses were performed using Stata statistical software, version 13.1 (StataCorp LP, College Station, Texas).
CR patients were younger (age 55 ± 8 years vs. 61 ± 11 years; p = 0.001) and were more often smokers (55% vs. 36.5%; p = 0.001) compared with non-CR patients. Sex, body mass index, and other cardiovascular risk factors were similar between the 2 groups.
Initial MI presentation appeared similar in terms of prevalence of anterior infarction, successful reperfusion, and complete revascularization, as well as time to reperfusion, creatine kinase peak, and infarct size (LV: 18.6 ± 12.2% vs. 19.5 ± 12.8%; p = 0.61).
The use of β-blockers and angiotensin-converting enzyme inhibitors did not differ between the groups at 1 year (overall 97.2% and 96.8%, respectively). Cardiovascular events occurred in 13 non-CR patients and 9 CR patients (p = 0.85) at 2 years.
At baseline and 3 months, the 2 groups were similar in terms of LV volumes, LVEF, and infarct size (Figure 1). Multivariate mixed regression analyses showed a decrease in LVESV among the entire population at follow-up. Age older than 60 years, infarct size >20% of the LV, and anterior infarction were related to a greater baseline LVESV. CR was independently associated with an increase in LVESV between 3 months and 1 year (β = 2.949; 95% confidence interval: 0.0385 to 5.514; p = 0.024). We found an interaction for the effect of CR with a baseline LVEF of <40% or ≥40% on the change in LVESV. Patients with a baseline LVEF of <40% presented with a greater increase in both LVEDV and LVESV, which resulted in a maintained LVEF (Figure 1).
We found no relationship between LVR and the time from MI to CR (Pearson’s r = 0.117; p = 0.34) or the exercise change required to perform CR (Pearson’s r = −0.037; p = 0.76).
The present cardiac magnetic resonance study showed that STEMI patients with baseline depressed LVEF may be at risk of adverse remodeling after CR, despite optimal medical therapy. Nevertheless, CR was shown to reduce both LVR and cardiovascular events (4) in stable patients with heart failure and depressed LVEF, but a meta-analysis by Haykowski et al. (5) suggested that CR should be started earlier to better to limit LVR. There is a need for additional research on timing, intensity, duration, and patient selection for CR after MI.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2019 American College of Cardiology Foundation
- Ibanez B.,
- James S.,
- Agewall S.,
- et al.
- Ellingsen Ø.,
- Halle M.,
- Conraads V.,
- et al.