Preexisting frailty and outcomes in older patients with acute myocardial infarction

Background: Little is known about the prevalence and prognostic impact of preexisting frailty on acute care and in-hospital outcomes in older adults in the setting of acute myocardial infarction (AMI).

Methods: Preexisting frailty was assessed at baseline in consecutive AMI patients ≥65 years of age treated at 778 hospitals participating in the NCDR ACTION Registry between January 1, 2015 to December 31, 2016. Three domains of preexisting frailty (cognition, ambulation, and functional independence) were abstracted from chart review and summed in 2 ways: an ACTION Frailty Scale based on responses to 6 groups adapted from the Canadian Study of Health and Aging Clinical Frailty Scale and an ACTION Frailty Score derived by summing a rank score of 0-2 assigned for each grade (total ranged between 0 to 6). Multivariable logistic regression examined the association between assigned frailty by score or scale and in-hospital mortality.

Results: Among 143,722 older AMI patients, 108,059 (75.2%) were fit and/or well and 6,484 (4.5%) were vulnerable to frailty, while 7,527 (5.2%) had mild, 3,913 (2.7%) had moderate, 2,715 had (1.9%) severe, and 632 (0.4%) had very severe frailty according to the ACTION Frailty Scale, while 14,392 (10.0%) could not be categorized due to incomplete ascertainment. Frail patients were older, more frequently female, of non-white race and/or ethnicity, and less likely to be treated with guideline-recommended therapies. Increasing severity of frailty by this scale was associated with a step-wise higher risk for in-hospital mortality (P-trend < .001). Patient categories of the ACTION Frailty Score provided similar results. After adjustment, each 1-unit increase in Frailty Score was associated with a 12% higher mortality risk (OR 1.12, 95% CI 1.10-1.15).

Conclusions: Among older patients with acute myocardial infarction, frailty is common and independently associated with in-hospital mortality. These findings show the importance of pragmatic evaluation of frailty in hospital-level quality scores, guideline recommendations, and incorporation into other registry data collection efforts.