Abstract
BACKGROUND: 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 acute myocardial infarction (AMI) patients. METHODS: Subjects comprised 277 AMI patients who underwent percutaneous coronary intervention (PCI). Associations between all-cause and cardiac deaths after PCI and baseline characteristics including living alone and Global Registry of Acute Coronary Events (GRACE) risk score were assessed. RESULTS: Eighty-three patients (30%) were living alone. 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). Multivariate Cox proportional hazards regression analysis models showed living alone [hazard ratio (HR), 2.60; 95% confidence interval (CI), 1.20-5.62; P = 0.016 and HR, 4.17; 95% CI, 1.60-10.84; P = 0.003] and GRACE risk score (HR, 1.02; 95% CI, 1.01-1.03; P = 0.003 and HR, 1.03; 95% CI, 1.01-1.04; P < 0.001) correlated significantly with all-cause and cardiac deaths. Cox proportional hazards modeling revealed that patients living alone with GRACE risk score ≥162 derived from the receiver-operating characteristic curve showed a significantly greater risk of all-cause death than patients not living alone with GRACE risk score <162 (HR 16.57; 95% CI 6.67-41.21; P < 0.001). CONCLUSION: Among AMI patients, living alone represents an independent risk factor for all-cause and cardiac deaths after PCI, separate from GRACE risk score. Furthermore, AMI patients living alone with high GRACE risk scores may experience an additively increased risk of mortality after PCI.