Plasma Follistatin-Like Protein 1 Is Correlated With Disease Severity in Patients With Acute Pulmonary Embolism and Predicts Short-Term Mortality

: We investigated the plasma levels of follistatin-like protein 1 (FSTL1) in patients with acute pulmonary embolism (PE) and whether it could predict short-term mortality. A prospective observational cohort study was conducted in patients with acute PE (n = 220). FSTL1 was measured in plasma samples using enzyme-linked immunosorbent assay. Plasma FSTL1 levels were significantly increased in patients with acute PE, and positively correlated with disease severity (rs = 0.7171). Sensitivity and specificity rates for high-risk PE at a specific FSTL1 cutoff point (23 ng/ml) were 79.3% and 92.9%. Multivariant Cox regression analysis showed that FSTL1 was independently associated with 30-day mortality rate. Addition of FSTL1 to the PE severity index (PESI) scoring system significantly improved the predictive value for 30-day mortality. These results indicate that the plasma level of FSTL1 is correlated with disease severity in patients with acute PE and predicts short-term mortality.