Frailty and outcomes after myocardial infarction: Insights from the CONCORDANCE registry

Background-—Little is known about the prognostic implications of frailty, a state of susceptibility to stressors and poor recovery to homeostasis in older people, after myocardial infarction (MI). Methods and Results-—We studied 3944 MI patients aged ≥65 years treated at 41 Australian hospitals from 2009 to 2016 in the CONCORDANCE (Australian Cooperative National Registry of Acute Coronary Care, Guideline Adherence and Clinical Events) registry. Frailty index (FI) was determined using the health deficit accumulation method. All-cause and cardiac-specific mortality at 6 months were compared between frail (FI >0.25) and nonfrail (FI ≤0.25) patients. Among 1275 patients with ST-segment-elevation MI (STEMI), 192 (15%) were frail, and among 2669 non-STEMI (NSTEMI) patients, 902 (34%) were frail. Compared with nonfrail counterparts, frail STEMI patients received 30% less reperfusion therapy and 22% less revascularization during index hospitalization; frail NSTEMI patients received 30% less diagnostic angiography and 39% less revascularization. Unadjusted 6-month all-cause mortality (STEMI: 13% versus 3%; NSTEMI: 13% versus 4%) and cardiac-specific mortality (STEMI: 6% versus 1.4%, NSTEMI: 3.2% versus 1.2%) were higher among frail patients. After adjustment for known prognosticators, FI was significantly associated with higher 6-month all-cause (STEMI: odds ratio: 1.74 per 0.1 FI [95% confidence interval, 1.37-2.22], P<0.001; NSTEMI: odds ratio: 1.62 per 0.1 FI [95% confidence interval, 1.40-1.87], P<0.001) but not cardiac-specific mortality (STEMI: P=0.99; NSTEMI: P=0.93). Conclusions-—Frail patients receive lower rates of invasive cardiac care during MI hospitalization. Increased frailty was independently associated with increased postdischarge all-cause mortality but not cardiac-specific mortality. These findings inform identification of frailty during MI hospitalization as a potential opportunity to address competing risks for mortality in this high-risk population.