Novel risk model predicts 6-month post-AMI mortality in older adults

A new risk model for predicting 6-month mortality for older adults hospitalized with acute myocardial infarction (AMI) has been developed, demonstrating good calibration and discrimination, reports a recent study.

The model may prove useful in decision making at hospital discharge, the researchers said.

This prospective cohort study was conducted in 94 hospitals across the US and enrolled 3,006 persons aged ≥75 years who were hospitalized with AMI and discharged alive. Either direct measurement or self-report was employed to assess functional impairments during hospitalization. A chart review was performed to ascertain clinical variables associated with mortality in prior risk models.

The researchers selected 72 candidate variables for inclusion. They used backward selection and Bayesian model averaging to derive (n=2,004) and validate (n=1,002) a model for 6-month post-AMI mortality.

Of the participants (mean age, 81.5 years; 44.4 percent women; 10.5 percent nonwhite), 266 died (8.8 percent) within 6 months. The final risk model included 15 variables, of which four (ie, hearing impairment, mobility impairment, weight loss and lower patient-reported health status) were not included in previous risk models.

The model was well calibrated (Hosmer–Lemeshow p>0.05) and had good discriminatory ability (area under the curve for the validation cohort, 0.84). The addition of functional impairments led to significant improvements in model performance, as shown by category-free net reclassification improvement indices of 0.21 (p=0.008) for hearing impairment and 0.26 (p<0.001) for mobility impairment.

The new model, however, was not validated externally, according to the researchers.