LAUSR

Background Cardiac injury is frequently encountered in patients with COVID-19 and is associated with an increased risk of mortality. Elevated troponin may signify myocardial damage and predicts mortality. We aimed to assess the prognostic value of elevated troponin above the 99th percentile upper reference limit (URL) on mortality and factors affecting their relationship. Methods We performed a comprehensive literature search using PubMed (MEDLINE), Scopus, and Embase from inception of the search databases until 16th December 2020. The key exposure was elevated serum troponin, defined as troponin (of any type) elevation > 99th percentile URL. The outcome was mortality due to any causes. Results There were a total of 12,262 patients from 13 studies in this systematic review and meta-analysis. Mortality was present in 23% (20-26%) of the patients. Elevated troponin was present in 31% (23-38%) of the patients. Elevated troponin was associated with increased mortality (OR 4.75 [4.07, 5.53], p < 0.001; I2: 19.9%). Meta-regression shows that the association did not vary with age (p = 0.218), male gender (p = 0.707), hypertension (p = 0.182), diabetes (p = 0.906), and coronary artery disease (p = 0864). Elevated troponin was associated with sensitivity of 0.55 [0.44, 0.66], specificity of 0.80 [0.71, 0.86], PLR 2.7 of [2.2, 3.3], NLR of 0.56 [0.49, 0.65], DOR of 5 [4, 5], and AUC of 0.73 [0.69, 0.77]. Elevated troponin resulted in a 45% probability for mortality and non-elevated troponin resulted in a 14% probability for mortality. Conclusion Elevated troponin was associated with increased mortality with a 55% sensitivity and 80% specificity.