Invasive treatment strategy in elderly patients with non ST elevation acute coronary syndromes. A sensitivity analysis of a large monocentric retrospective study

Abstract

Background: Consistent benefit of invasive strategy (IS) in the management of myocardial infarction (MI) in elderly patients is not yet reported. Objectives: In non ST elevation acute coronary syndromes (NSTEACS) admitted within 48h of symptom onset, we aimed to determine in-hospital and 30-days mortality, and proportion of patients alive at 31 days to 6 months (T1) and 31 days to 12 months follow-up (T2). Cumulative rate of composite outcome (CO) of death/nonfatal MI/unstable angina was also analysed at 30 days, 6 and 12 months. Methods: A retrospective review of 453 consecutive patients > 75 yrs discharged after NSTEACS at a single ICCU between 2006 and 2010 was conducted. IS (n=301) or conservative strategy (CS) (n=152) were chosen as per medical judgment. Multivariate regression models to test the association between strategy and outcomes were used and a sensitivity analysis performed. Variables introduced into the models were age, gender, admission creatinine clearance, ejection fraction, haemoglobin and Killip classes, admission heart rate, blood pressure and cardiac arrest, ST deviation, peak troponin level, time from admission to percutaneous coronary intervenion (PCI), albumin serum levels. Results: Inhospital, 8 (2.7%) and 14 (9.2%), at 30 days, 11 (3,7%) and 21 (13,8%), at T1 28 (9,3%) and 44 (29,0%), and at T2 40 (13,3%) and 57 (37.5%), patients died in the IS and CS group respectively. At 30 days 25 (8,3%) and 24 (15,8%), at T1 52 (17,3%) and 56 (36,8%), and at T2 74 (24,6%) and 64 (42.1%), patients achieved the cumulative CO in the IS and CS group respectively. IS sizeably decreased adjusted in-hospital (OR 0.37, 95% CI 0.13-1.04, p=0.0603), 30-days (OR 0.28, 95% CI 0.12-0.67, p=0.004), T1 (T1 OR 0.33, 95% CI 0.16-0.67, p=0.0025) and T2 mortality (T2 OR 0.34, 95% CI 0.20-0.58, p=0.0001). IS correspondingly lowered cumulative rate of CO at 30 days (OR 0.55, 95% CI 0.28-1.07, p = 0.077), 6 months (OR 0.52, 95% CI 0.34-0.81, p = 0.003) and 12 months (OR 0.68, 95% CI 0.46-0.98, p = 0.0041). Further independent predictors of prognosis were also hemodynamic status (Killip class II-IV), or cardiac arrest at admission. Conclusions: IS was independently associated with a three-fold lower mortality and twofold lower CO in this high risk population at either brief, mid or long-term.