Syncope: Outcomes and Conditions Associated with Hospitalization

Syncope is a perplexing problem for which hospital admission and readmission are contemplated but outcomes remain uncertain. Our purpose was to determine the incidence of admissions and readmissions for syncope and compare associated conditions, in-hospital outcomes, and resource utilization.

The 2005-2011 California Statewide Inpatient Database was utilized. Patients of age ≥18 years admitted under International Classification of Diseases, Ninth Revision, Clinical Modification code 780.2 ("syncope or collapse") were selected. Records with a primary discharge diagnosis of syncope were classified as primary syncope. Primary outcome was mortality and secondary outcome measures were cardiopulmonary resuscitation, mechanical ventilation, discharge disposition, length of stay, frequency of readmission and hospital charges.

An estimated 1.52 ± 0.02% admissions every year are related to syncope. Among admissions for syncope, in 42.1%, the cause remained unknown; 23% of syncope admissions were for recurrent episodes. The top 5 associated new diagnoses were hypokalemia (0.24%), ventricular tachycardia (0.17%), atrial fibrillation (0.16%), dehydration (0.12%), and hyponatremia (0.12%). Mortality rates are lower for primary vs secondary syncope (0.2% vs 1.4%; P <.0001). Greatest risk factors for mortality in primary syncope were pulmonary hypertension (odds ratio 12.3; 95% confidence interval, 3.34-45.04) and metastatic cancer (odds ratio 7.22; 95% confidence interval, 4.50-11.58). Major adverse events showed a decreasing trend for patients with multiple syncope admissions. Older patients and defibrillators or pacemaker recipients are admitted more often but experience negligible adverse events. Over a decade, median hospital charge for a single syncope admission has increased by 1.5 times.

Despite a good prognosis, syncope is a frequent cause for hospitalization, particularly in the elderly. Present evaluation strategies are expensive and lack diagnostic value.