Delirium risk factors in patients ≥ 60 years of age with recent myocardial infarction

Delirium is a form of acute brain dysfunction and geriatric patients are particularly vulnerable to this health problem. The aim of the study was to assess the incidence of delirium and determine the risk factors for delirium in patients ≥ 60 years of age hospitalized due to acute myocardial infarction (AMI).

The study included 405 consecutive patients (mean age: 73.1 ± 8.5, males: 61%) hospitalized due to AMI divided and characterized according to the in-hospital delirium presence.

Of 405 patients, 57 (14%, mean age: 80.9 ± 7.3, males: 58%) experienced delirium. Patients with delirium were older (80.9 ± 7.3 vs. 71.82 ± 8.1 years), all of them presented multimorbidity, they more frequently used polypharmacy (96.5 vs. 30.2%) and their hospitalization was longer (8.0 ± 1.4 vs. 4.6 ± 1.0 days) as compared to the patients without delirium. Patients with delirium more frequently experience periprocedural complications as well as the in-hospital reversible problems: fever (40.4 vs. 0.9%), infections (78.9 vs. 3.7%), pulmonary oedema (73.7 vs. 0.6%), hypoxemia (91.1 vs. 98.3%), urinary catheter (96.5 vs. 17.2%), dehydration (89.5 vs. 6.6%), and insomnia (71.9 vs. 0.3%) compared to patients without delirium (P < 0.001 for all). Valvular heart disease (OR = 4.78; 95%CI: 1.10-2.70; P < 0.001, pulmonary oedema (OR = 66.79; 95%CI: 12.04-370.34, P < 0.001), and dehydration (OR = 37.26; 95%CI: 10.50-132.27, P < 0.001) were risk factors for delirium occurrence.

The in-hospital course of AMI is complicated by delirium occurrence in 14% of patients ≥ 60 years old. Recognizing and modification of potential, reversible risk factors associated with AMI can reduce the risk of delirium.