Clinical and prognostic implications of delirium in elderly patients with non–ST-segment elevation acute coronary syndromes

Background Elderly patients with non-ST-segment elevation acute coronary syndromes(NSTE-ACS) may present delirium but its clinical relevance is unknown. This study aimed at determining the clinical associated factors, and prognostic implications of delirium in old-aged patients admitted for NSTE-ACS. Methods LONGEVO-SCA is a prospective multicenter registry including unselected patients with NSTE-ACS aged ≥80 years. Clinical variables and a complete geriatric evaluation were assessed during hospitalization. The association between delirium and 6-month mortality was assessed by a Cox regression model weighted for a propensity score including the potential confounding variables. We also analysed its association with 6-month bleeding and cognitive or functional decline. Results Among 527 patients included, thirty-seven(7%) patients presented delirium during the hospitalization. Delirium was more frequent in patients with dementia or depression and in those from nursing homes(27.0% vs. 3.1%, 24.3% vs. 11.6%, and 11.1% vs. 2.2%, respectively; all P < 0.05). Delirium was significantly associated with in-hospital infections(27.0% vs. 5.3%, P < 0.001) and usage of diuretics(70.3% vs. 49.8%, P = 0.02). Patients with delirium had longer hospitalizations [median 8.5(5.5-14) vs. 6.0(4.0-10) days, P = 0.02] and higher incidence of 6-month bleeding and mortality(32.3% vs. 10.0% and 24.3% vs. 10.8%, respectively; both P < 0.05) but similar cognitive or functional decline. Delirium was independently associated with 6-month mortality(HR = 1.47, 95% CI: 1.02-2.13, P = 0.04) and 6-month bleeding events(OR = 2.87; 95% CI: 1.98-4.16, P < 0.01). Conclusions In-hospital delirium in elderly patients with NSTE-ACS is associated with some preventable risk factors and it is an independent predictor of 6-month mortality.