Long-term outcomes in syncope patients presenting to the emergency department: A systematic review

Introduction Long-term outcomes among syncope patients are not well studied to guide physicians regarding outpatient testing and follow-up. The objective of this study was to conduct a systematic review for outcomes at 1-year or later among ED syncope patients. Methods We searched Cochrane Central, Medline, Medline in Process, PubMed, Embase, and the Cumulative Index to Nursing databases from inception to December 2018. We included studies that reported long-term outcomes among ED syncope patients. We excluded studies on patients <16 years old, studies that included syncope mimickers (pre-syncope, seizure, intoxication, loss of consciousness after head trauma), case reports, letters to the editor, non-English and review articles. Outcomes included death, syncope recurrence requiring hospitalization, arrhythmias and procedural interventions for arrhythmias. Meta-analysis was performed by pooling the outcomes using random effects model. Results Initial literature search generated 2,094 articles duplicate removal. Of the 50 articles selected for full-text review, 19 articles with 98,211 patients were included in this review: of which 12 were included in the 1-year outcome meta-analysis. Pooled analysis showed : 7.0% mortality; 16.0% syncope recurrence requiring hospitalization; 6.0% with device insertion. 1-year arrhythmias reported in two studies were 1.1 and 26.4%. Pooled analysis for outcome at 31 to 365 days showed: 5.0% mortality and 1% device insertion. Two studies reported 4.9% and 21% mortality at 30 months and 4.2 years follow-up. Conclusions An important proportion of ED syncope patients suffer long-term morbidity and mortality. Appropriate follow-up is needed and future research to identify patients at risk is needed.