An invasive strategy is associated with improved short- and long-term outcomes in acute myocardial infarction independently of frailty status and GRACE score: a nationwide analysis of 12144 episodes

Introduction Frailty is common among patients presenting with acute myocardial infarction (MI), who have conflicting risks regarding benefits and harms of invasive procedures. Purpose To assess the clinical management and prognostic impact of invasive procedures in frail MI patients in a real-world scenario. Methods We analysed 5422 episodes of ST-elevation MI (STEMI) and 6692 of Non-ST-elevation MI (NSTEMI) recorded from 2010–2019 in a nationwide registry. A validated deficit-accumulation model was used to create a frailty index (FI), comprising 22 features [BMI >25kg/m2, myocardial infarction, angina, heart failure, percutaneous coronary intervention (PCI), coronary artery bypass graft surgery (CABG), valvular disease, bleeding, pacemaker/implantable cardioverter defibrillator, chronic kidney disease (creatinine >2.0mg/dL), dialysis/renal transplant, stroke/transient ischaemic attack, diabetes, hypertension, dyslipidaemia, smoking, peripheral vascular disease, dementia, chronic lung disease, malignancy, polymedication (>3 cardiovascular drugs), admission haemoglobin <10g/dL; not including age]. Episodes with missing data on any FI parameter were not included. Frailty was initially defined as FI>0.25 (i.e. ≥6 features). Results Overall, 511 (9.4%) STEMI and 1763 (26.4%) NSTEMI patients were considered frail. Angiography, PCI and CABG were less frequently performed in frail patients (p<0.001). Delayed angiography (>72h) was more common among NSTEMI frail patients (p<0.001), and radial access was less commonly used overall (p<0.001). Guideline-recommended in-hospital medical therapy, including aspirin (NSTEMI), dual-antiplatelet therapy (STEMI/NSTEMI), heparin/heparin-related agents (NSTEMI), beta-blockers (STEMI) and ACEIs/ARBs (STEMI), was less commonly used in frail patients; discharge medical therapy exhibited similar patterns. Frail patients had longer hospital stay and increased in-hospital all-cause and cardiovascular (CV) mortality, as well as 1-year all-cause and CV hospitalization and all-cause mortality (p<0.001). Using receiver-operator-characteristics curve analysis, FI cutoffs of 0.11 (STEMI) and 0.20 (NSTEMI) yielded the best accuracy to predict 1-year all-cause mortality (area under the curve: 0.629 and 0.702 respectively, p<0.001) – these cutoffs were subsequently used to define frailty. Although frailty attenuated in-hospital risk reductions from angiography (STEMI/NSTEMI) and PCI (NSTEMI only) (Wald test p<0.05), their 1-year prognostic benefit remained unaffected (Wald test p>0.05). Angiography and PCI were associated with improved in-hospital and 1-year outcomes, independently of frailty status or GRACE score (p<0.001). Conclusion Frail MI patients are less commonly offered standard therapy; however, angiography and PCI were associated with short- and long-term prognostic benefits regardless of frailty status or GRACE score. Increased adherence to current recommendations might improve post-MI outcomes in frail patients. Invasive strategy and 1-year outcomes Funding Acknowledgement Type of funding source: Other. Main funding source(s): Portuguese Society of Cardiology