Multimorbidity, functional impairment, and mortality in older patients stable after prior acute myocardial infarction: Insights from the TIGRIS registry

Background: Data on the association of multimorbidity and functional impairment with cardiovascular (CV) and non-CV outcomes among older myocardial infarction (MI) patients are limited. Hypothesis: Multimorbidity and functional impairment among older MI patients are associated with CV and non-CV mortality. Methods: Patients aged ≥65 years, 1−3 years post-MI, and enrolled between June 2013 and Novemeber 2014 from 349 sites in 25 countries in the global TIGRIS registry were categorized by age, number of comorbidities, and presence and degree of functional impairment. Functional impairment was calculated using five-dimension EuroQol based on three domains—mobility, self-care, and usual activities. The association between age, number of comorbid conditions, and degree of functional impairment with 2-year incidence of CV and non-CV death was evaluated using Poisson regression analysis. Results: Older age was associated with higher number of comorbidities and functional impairment; after adjustment, increasing age was significantly associated with non-CV mortality (p =.03) but not CV mortality (p =.38). Greater functional impairment was associated with a higher rate and relatively equal magnitude risk of CV (rate ratios [RR] 1.52, 95% confidence intervals [CI]: 1.29−1.79, per one-step increase) and non-CV mortality (RR 1.42, 95% CI: 1.17−1.73). Multimorbidity was more strongly associated with CV mortality (RR 1.52, 95% CI: 1.38−1.67, per additional comorbidity) versus non-CV mortality (RR 1.29, 95% CI: 1.14−1.47, per additional comorbidity). Conclusions: Multimorbidity and functional impairment are prevalent among older post-MI patients and are associated with increased CV and non-CV mortality. These findings highlight the importance of considering comorbid conditions and functional impairment as predictors of risk for adverse outcomes and aspects of medical decision making. Clinical Trial Registration: NCT01866904.