Revascularization in frail patients with acute coronary syndromes: a retrospective longitudinal study

Frailty is increasingly prevalent in people presenting with acute coronary syndrome (ACS). This high-risk group is typically excluded from trials of interventions in ACS, and there is uncertainty about the risks and benefits of invasive management. Patients with an ACS diagnosis between 2010 and 2015 in England were identified from Hospital Episode Statistics, with linked Office for National Statistics mortality data. Frailty was defined by the Hospital Frailty Risk Score. Causal inference analysis used regional variation in revascularization as an instrumental variable to estimate average treatment effects of revascularization on cardiovascular mortality up to 5 years in people presenting with ACS and low-, intermediate-, or high-risk frailty. The analysis included 565 378 ACS patients, of whom 11.6% (n = 65 522) were at intermediate risk and 4.7% (n = 26 504) were at high risk of frailty. Intermediate and high frailty risks were associated with reduced likelihood of echocardiography, invasive angiography, or revascularization and increased likelihood of mortality and major adverse cardiovascular events compared with low frailty risk. Cardiovascular death at 5 years was 78.6%, 77.3%, and 75.7% in people at low, intermediate, and high frailty risk, respectively. Instrumental variable analysis suggested that revascularization resulted in a higher absolute reduction in cardiovascular mortality in high and intermediate frail risk patients compared with low risk at 1-year post-ACS. Frailty is common in people presenting with ACS, where cardiovascular causes are the principal mode of death. Revascularization is associated with short- and long-term survival benefits in people at intermediate and high risk of frailty after adjustment for measured and unmeasured confounders.