Abstract

Background: The TIMI risk score is a well-validated scoring system used to predict mortality in patients following an ST-segment elevation myocardial infarction (STEMI). N-terminal pro-B-type natriuretic peptide (NTproBNP) has also been found to be useful in predicting mortality following STEMI.

Objective: To investigate the utility of the TIMI score and NTproBNP levels at predicting risk of death in patients with acute myocardial infarction (AMI).

Methods: 473 patients (352 men, mean (SD) age 63.7 (12.3) years) with AMI were studied. Blood was drawn within 24 hours after the onset of chest pain and the plasma concentration of NTproBNP was determined using an in-house non-competitive immunoassay. Patients’ TIMI risk score was measured and patients stratified into low- (0 to 2), intermediate- (3–7) and high-risk (>8) groups.

Results: Mortality was 8.9% and was related to higher TIMI risk scores (p = 0.029 for trend). Higher NTproBNP levels were also related to increased mortality (median (range) fmol/ml, survivors 700.2 (0.3–11485.3) vs dead 5781.3 (1.4–10835.9), p<0.001). In a multivariate binary logistic regression model, independent predictors of mortality were NTproBNP levels in the first 24 hours (odds ratio (OR) = 4.21, 95% CI 1.96 to 9.07, p<0.001) together with drug treatments. The receiver operating curve for NTproBNP in the first 24 hours yielded an area under the curve (AUC) of 0.79 (95% CI 0.70 to 0.88), p<0.001, for TIMI risk score the AUC was 0.67 (95% CI 0.58 to 0.76), p = 0.001.

Conclusion: In the first 24 hours following an AMI, NTproBNP is better than the TIMI risk score at predicting mortality. A simple NTproBNP blood test is more easily applicable and is more accurate than a clinical risk score.