Predictors of mortality, rehospitalization for syncope, and cardiac syncope in 352 consecutive elderly patients with syncope

Objectives: To investigate the etiologies of syncope and predictors of all-cause mortality, rehospitalization, and cardiac syncope in consecutive elderly patients presenting with syncope to our emergency department.

Participants: Participants were 352 consecutive patients aged 65 years or older with syncope admitted to hospital from the emergency department.

Design: Observational retrospective study.

Measurements: Review of medical records for history, physical examination, medications, and tests to determine causes of syncope. Cox stepwise logistic regression analysis was performed to identify significant independent prognostic factors for rehospitalization with syncope, all-cause mortality, and cardiac syncope.

Results: Of 352 patients, mean age 78 years, the etiology of syncope was diagnosed in 243 patients (69%). Vasovagal syncope was diagnosed in 12%, volume depletion in 14%, orthostatic hypotension in 5%, cardiac syncope in 29%, carotid sinus hypersensitivity in 2%, and drug overdose/others in 7% of patients. During a mean follow-up of 24 months, 10 patients (3%) were readmitted to the hospital for syncope and 39 (11%) died. Stepwise logistic regression analysis identified history of congestive heart failure (OR 5.18; 95% CI 1.23-21.84, P = .0257) and acute coronary syndrome (OR 5.95; 95% CI 1.11-31.79, P = .037) as independent risk factors for rehospitalization. Significant independent prognostic factors for mortality were diabetes mellitus (OR 2.08; 95% CI 1.09-3.99, P = .0263), history of smoking (OR 2.23; 95% CI 1.10-4.49, P = .0255), and use of statins (OR 0.37; 95% CI 0.19-0.72, P = .0036). Independent risk factors for predicting a cardiac cause of syncope were an abnormal electrocardiogram (OR 2.58; 95% CI 1.46-4.57, P = .0012) and reduced ejection fraction (OR 2.92; 95% CI 1.70-5.02, P < .001). The San Francisco Syncope Rule and Osservatorio Epidemiologico sulla Sincope nel Lazio scores did not predict mortality or rehospitalization in our study population.

Conclusions: Significant independent risk factors for rehospitalization for syncope were congestive heart failure and acute coronary syndrome. Significant independent risk factors for mortality were diabetes mellitus, history of smoking, and use of statins (inverse association).