Older coronary thrombus is an independent predictor of 1-year mortality in acute myocardial infarction

Background We have previously shown that older thrombus is associated with a twofold higher long-term mortality in ST-segment elevation myocardial infarction (STEMI) patients after primary percutaneous coronary intervention (pPCI). We evaluated whether the addition of the presence of older thrombus to a multimarker model would result in increased predictive power for 1-year mortality in STEMI patients. Methods The study population (n = 1442) consists of STEMI patients treated with thrombus aspiration during pPCI. Patients were included if aspirated thrombus material could histopathologically be classified according to thrombus age (n = 870) and laboratory measurements of biomarkers (cardiac troponin T, glucose, N-terminal pro-brain natriuretic peptide, estimated glomerular filtration rate and C-reactive protein) were available. The additional prognostic value of the presence of older thrombus beyond multiple biomarkers and established clinical risk factors was evaluated using multivariate Cox regression models. Results Serum biomarker concentrations were similar between patients with fresh and older thrombus. Sixty patients (7%) died within 1 year. The presence of older thrombus remained strongly associated with mortality at 1 year after multivariable adjustment for multiple biomarkers and established clinical risk factors. Addition of older thrombus to either a model including clinical risk factors and biomarkers or a model including solely biomarkers resulted in significant increases in the discriminative value, evidenced by net reclassification improvement and integrated discriminative improvement. Conclusions The presence of older thrombus provides independent complementary information to a multimarker model including established clinical risk factors and multiple biomarkers for predicting 1-year mortality in STEMI patients treated with pPCI and thrombus aspiration.