Background:
Participation in cardiac rehabilitation (CR) has been shown to decrease mortality following acute myocardial infarction (MI), but its impact on rehospitalizations requires examination.
Methods:
We included patients who were hospitalized with first-ever MI in Olmsted County Minnesota from 1987-2010 and survived to hospital discharge. Participation in CR within the first 30 days following MI was determined using billing data and was analyzed as a time-dependent covariate. The association between CR participation and all-cause rehospitalization was analyzed using Andersen-Gill models to account for repeated events. As CR participation is a non-randomized intervention, we adjusted for propensity to participate after fitting a logistic regression model using 13 factors significantly associated with participation on univariate analysis. Patients were censored at the time of death or last follow-up.
Results:
Among 2991 patients (mean age 67 years, 59% male, 31% ST elevation MI), 1480 (49%) participated in CR following acute MI hospital discharge (first session occurred at a mean of 9 days post-discharge). Most patients (75%) were rehospitalized at least once during a mean follow-up of 7.6 years, and CR participation was associated with reduced risk of rehospitalization. The rehospitalization rates were 39% and 59% at one year for participants and non-participants, respectively. In unadjusted analysis, CR participation was associated with a markedly decreased risk of rehospitalization (HR 0.51, 95% CI 0.49-0.53, p<0.001). After adjusting for propensity to participate, the association between CR participation and all-cause rehospitalization persisted (HR 0.70, 95% CI 0.67-0.73, p<0.001).
Conclusions:
CR participation is associated with a markedly reduced risk of rehospitalization after incident MI. In addition to reducing mortality, improving CR participation rates may have a large impact post-MI healthcare resource use.
Impact of excercise training cardiac rehabilitation on QTc and QT dispersion in post myocardial infarction patients
