External validation and extension of the TIMI risk score for heart failure in diabetes for patients with recent acute coronary syndrome: An analysis of the EXAMINE trial

The Thrombolysis in Myocardial Infarction Risk Score for Heart Failure (HF) in Diabetes (TRS-HFDM ) prognosticates HF hospitalization in people with type 2 diabetes (T2D). This study aimed to externally validate and extend its use for those with recent acute coronary syndrome (ACS).The TRS-HFDM was externally validated in the Examination of Cardiovascular Outcomes with Alogliptin versus Standard of Care (EXAMINE) trial (n = 5380) and extended with natriuretic biomarkers. Missing data were multiply imputed. Initial TRS-HFDM variables were previous HF (2 points), atrial fibrillation (1 point), coronary artery disease (1 point), estimated glomerular filtration rate <60 ml/min/1.73 m2 (1 point), and urine albumin-to-creatinine ratio 30-300 mg/g (1 point) and >300 mg/g (2 points).In total, HF hospitalization occurred in 193 (3.6%) patients. Based on the TRS-HFDM , 25% of patients were classified as intermediate risk (1 point), 30% were classified as high risk (2 points), 19% were classified as very-high risk (3 points) and 26% were classified as severe risk (≥4 points). Before model extension, discrimination (C-index 0.76, 95%·CI 0.73-0.80) and calibration (calibration slope 0.82, 95%·CI 0.65-1.0; calibration-in-the-large -0.15, 95%·CI -0.37-0.64) were moderate-to-good in individuals with T2D and recent ACS. The extension of TRS-HFDM with the addition of N-terminal pro-B-type natriuretic peptide (NT-ProBNP) improved discrimination (C-index 0.82, 95%·CI 0.79-0.85) and calibration (calibration slope 0.84, 95%·CI 0.66-1.02; calibration-in-the-large -0.12, 95%·CI -0.33-0.081) for this higher-risk population.The TRS-HFDM with the extension of NT-ProBNP improves risk stratification and generalizes the use of the risk score for patients with T2D and ACS. Future validation studies in ACS populations may be warranted.