Risk model assesses function in older patients after hospitalization for acute MI

Five factors, including longer hospital stay and depression, were associated with declines in activities of daily living six months after discharge for a myocardial infarction (MI).

A new risk model may help predict declines in activities of daily living in older adults who are hospitalized for acute myocardial infarction (MI), a recent study found.

Researchers used data from the prospective SILVER-AMI (Comprehensive Evaluation of Risk Factors in Older Patients With Acute Myocardial Infarction) study to evaluate the incidence of functional decline in a nationwide cohort study of older adults hospitalized with acute MI and develop a risk model to help identify at-risk patients. Data on demographic, cardiac, geriatric, psychosocial, and lifestyle variables were collected during hospitalization and six months afterward. Functional decline was defined as decreased ability to independently perform essential activities of daily living (such as bathing, dressing, transferring, and ambulating) from baseline to six months postdischarge. The primary outcome was a decrease in at least one activity of daily living at six months. The results of the study were published Oct. 1 by the Journal of the American Heart Association.

Overall, 2,555 patients with acute MI were included in the main study analysis. Of these, 1,709 were randomly assigned to the derivation cohort and 846 were randomly assigned to the validation cohort. Mean age was 81.3 years, 56.7% were men, and 90.3% were White. A total of 327 patients (12.8%) reported declines in activities of daily living at six months after discharge, with older age (odds ratio [OR], 1.03; 95% CI, 1.00 to 1.07 per year), longer hospital stay (OR, 1.05; 95% CI, 1.02 to 1.08 per day), mobility impairment during hospitalization (ORs, 3.00 [95% CI, 1.79 to 5.04] and 6.67 [95% CI, 3.89 to 11.40] for moderate and severe impairment, respectively), and depression (OR, 1.92; 95% CI, 1.33 to 2.79) identified as risk factors. In addition, decline in activities of daily living was more common in patients who reported being “about as active” as or “less active” than their peers (ORs, 1.67 [95% CI, 1.16 to 2.41] and 1.71 [95% CI, 1.09 to 2.69], respectively) versus “more active.” Factors associated with decreased risk for functional decline were revascularization during hospitalization (ORs, 0.52 [95% CI, 0.35 to 0.78] for percutaneous coronary intervention and 0.24 [95% CI, 0.12 to 0.48] for coronary artery bypass grafting) and ability to walk a quarter mile before acute MI (OR, 0.70; 95% CI, −0.50 to 0.97). The researchers found that model discrimination (c=0.78) and calibration were both good.

Patients' reported function one month before hospitalization was considered to be their function at baseline, and some patients may have had functional decline at the time of hospitalization that resolved before six months, the authors noted. They also said that their model requires external validation before use in clinical settings. “After external validation, use of this tool may improve treatment planning and shared decision-making for older patients with [acute MI] at risk for this important patient-centered outcome,” they concluded.