Abstract 9896: Living Alone is a Poor Prognostic Factor of Mortality Among Patients With Acute Myocardial Infarction

Abstract

Introduction: Acute myocardial infarction (AMI) has been a major cause of death worldwide. Recently, living alone as a proxy for social isolation has been considered to increase the risk of cardiovascular disease. We thus investigated the impact of living alone on mortality in AMI patients. Methods: Subjects comprised 277 AMI patients who underwent percutaneous coronary intervention (PCI). Associations between all-cause death after PCI and baseline characteristics including living alone and Global Registry of Acute Coronary Events (GRACE) risk score, which is widely used for estimating mortality in AMI patients, were assessed. Results: Eighty-three patients (30%) were living alone and 194 patients (70%) were not. Median duration of follow-up was 1153 days (interquartile range, 560-1566 days). Thirty patients died after PCI including 20 cardiac deaths. Patients living alone showed higher incidences of both all-cause and cardiac deaths compared with patients not living alone (18% vs. 8%, p = 0.019 and 14% vs. 4%, p = 0.004, respectively). Multivariate Cox proportional hazards regression analysis modeling using relevant factors from univariate analysis showed living alone [hazard ratio (HR), 2.60; 95% confidence interval (CI), 1.20-5.62; p = 0.016] and GRACE risk score (HR, 1.02; 95%CI, 1.01-1.03; p = 0.003) correlated significantly with all-cause death. The interaction of GRACE risk score and living alone showed a value of p = 0.25. The optimal cut-off on the receiver-operating characteristic curve of GRACE risk score for predicting all-cause death was 162. Cox proportional hazards modeling using GRACE risk score and living alone revealed that patients living alone with GRACE risk score ≥162 showed a significantly greater risk of all-cause death than patients not living alone with GRACE risk score <162 (HR 11.50; 95%CI 5.59-23.67; p < 0.001). Conclusions: Among AMI patients, living alone represents an independent risk factor for all-cause death after PCI, separate from GRACE risk score. In addition, AMI patients living alone with high GRACE risk scores may experience an additively increased risk of mortality after PCI.