Background/Introduction: There is little knowledge of the association between physical activity (PA) level and the mortality risk post myocardial infarction (MI). Steffen/Batey et al (2000), concluded in a smaller study, that individuals who remained active or increased their level of PA after MI had a lower risk of death. However, in order to confirm this and adjust for confounders larger studies are needed.
Purpose: Explore any association between PA level after MI and all-cause mortality during follow-up in a large MI-cohort.
Methods: A national cohort study including all patients <75 years of age, with a diagnosis of MI between 1991-2014 (Swedish MI register SWEDEHEART). From the register self-reported PA, 6-10 weeks post MI, (i.e. number of sessions during the past seven days with moderate and/or vigorous PA lasting ≥30 minutes) was obtained. The answers were grouped into 0-1 sessions (inactive), 2-4 sessions (moderately active) and 5-7 sessions (regularly active). Associations were first assessed unadjusted, stratified by potential confounders (sex, age, smoking status, ejection fraction, ST-elevation and quality of life). Thereafter, a multiple logistic regression was performed to control for possible confounders.
Results: Complete data was obtained from 37 655 individuals (median 63 years, 74 % men). A total of 2512 deaths occurred during a mean of 4.1 years of follow-up. The mortality rate was 17.0 cases/1000 person-years. Moderate and regular activity, was associated with a lower risk of all-cause mortality (OR 0,356 95 %, CI 0,320-0,396 and OR 0,334, 95 % CI 0,305-0,366) compared to being physically inactive. The OR´s remained largely unchanged when stratifying for age, sex, NSTEM/STEMI and ejection fraction. However, active smokers had a lower OR, for subsequent death, as had patients with a low EQ5D. The associations persisted in the multiple logistic regression, after adjustment for confounders (Figure 1).
Conclusion(s): A higher level of physical activity seems to be associated with a lower risk of all-cause mortality. These results suggest that physical activity assessment is important post MI, not least as an important predictor.
2017. Vol. 24, article id 45