GDF15 and chronic kidney disease: The initial Cox proportional hazards model revealed that CKD (HR 28.13, 95%CI 4.84–163.38, p = 0.0002), HRCT lung fibrosis (HR 4.36, 95%CI 1.04–18.26, p = 0.045) and GDF-15 concentration (unit HR 1.0006, 95%CI 1.0002–1.0010, p = 0.003) were independent predictors of MACE occurrence.