Evolving burden and consequences of frailty in patients with acute myocardial infarction: evidence from a nationwide cohort

Background

Frailty is increasingly prevalent among patients with acute myocardial infarction (AMI), yet its impact on care delivery and long-term outcomes at a population level remains poorly characterised. We examined temporal trends in frailty, its association with evidence-based management, and its prognostic implications.

Methods

We analysed consecutive adults hospitalised with AMI in England and Wales between 2005 and 2019 using linked national registries. Frailty was assessed at index admission using the Secondary Care Administrative Records Frailty index and categorised as fit, mild, moderate, or severe. The primary outcome was 1-year all-cause mortality. Secondary outcomes included cardiovascular death, major adverse cardiovascular events (MACE), heart failure readmission, reinfarction, and major bleeding. Multivariable Cox and logistic regression models were used.

Results

Among 931,133 patients hospitalised with AMI, 29.4% were classified as fit, 36.2% had mild frailty, 21.8% moderate frailty, and 12.6% severe frailty. As shown in Table 1, increasing frailty was associated with older age, higher comorbidity burden, and a greater proportion of women. Median age increased from 61 years in fit patients to 80 years in those with severe frailty, while the proportion of females rose from 24.7% to 45.3%. Comorbidity burden increased markedly, with Charlson Comorbidity Index greater than 3 present in 0.5% of fit patients versus 55.6% of those with severe frailty. Patients with increasing frailty were more likely to present with NSTEMI, rising from 52.0% in fit individuals to 79.4% in severe frailty, and had worse haemodynamic profiles and left ventricular systolic function.

The prevalence of moderate or severe frailty increased from 22.8% in 2005 to 42.1% in 2019, with severe frailty alone rising from 5.3% to 16.6% (Figure 1). Increasing frailty was associated with lower use of evidence-based care, including coronary angiography, dual antiplatelet therapy, and referral to cardiac rehabilitation.

As shown in Figure 2, frailty demonstrated a strong graded association with adverse outcomes. Compared with fit patients, the adjusted hazard of 1-year all-cause mortality increased stepwise across frailty categories, with HR 1.65 (95% CI 1.61 to 1.70) for mild frailty, 2.33 (95% CI 2.27 to 2.40) for moderate frailty, and 3.01 (95% CI 2.93 to 3.10) for severe frailty. Similar dose–response relationships were observed for cardiovascular death, with HR 2.82 (95% CI 2.70 to 2.94), MACE, HR 2.56 (95% CI 2.51 to 2.60), heart failure readmission, HR 3.74 (95% CI 3.61 to 3.88), and major bleeding, HR 1.85 (95% CI 1.78 to 1.92), for severe frailty compared with fit individuals.

Conclusion

Frailty is increasingly common in contemporary AMI populations and is strongly associated with lower delivery of guideline-recommended care and substantially worse short- and long-term outcomes.Figure 2