Review article: Utility of troponin after syncope: A systematic review and meta-analysis.

The role of serum troponin testing in patients presenting to the ED after syncope is unclear. The aim of this systematic review was to examine the practice and utility of troponin testing among patients presenting to the ED after syncope. We conducted a search of MEDLINE, Embase, Cochrane Library, Web of Science and Scopus databases from 1990 to February 2017 using keyword and subject headings for syncope and troponin testing. Design and results of the included studies are extracted. Studies were assessed for heterogeneity and the pooled proportion of measured troponin and positive troponin result described. There were nine studies included for analysis. Significant statistical heterogeneity among studies was observed (P < 0.001). Using the random effects model, the pooled proportion of patients presenting to the ED after syncope who had troponin measured was 0.64 (95% CI 0.46-0.82). Among patients who had been troponin tested, the pooled proportion who had a positive result was 0.19 (95% CI 0.13-0.26). Variability among reported outcomes prevented further meta-analysis. Troponin testing was commonly performed for the assessment of patients with syncope with a substantial proportion returning positive results. The correlation between raised troponin and patient outcomes was not adequately reported. It is possible that an elevated troponin may indicate serious illness, rather than myocardial damage alone.