Prognostic value of age-adjusted d-dimer cutoff thresholds in patients with myocardial infarction treated by percutaneous coronary intervention

Abstract

Abstract Introduction The association between D-dimer and outcomes of patients with myocardial infarction (MI) remains controversial. Using age-adjusted D-dimer cutoff thresholds significantly improves the accuracy of diagnosis for thrombotic diseases. This study aimed to investigate the prognostic value of age-adjusted D-dimer in MI patients treated by percutaneous coronary intervention (PCI). Methods In this observational study, 3614 consecutive patients with MI treated by PCI were retrospectively recruited. The baseline age-adjusted D-dimer threshold was 500 ng/mL, and was calculated as age × 10 in patients older than 50 years. Cox regression was used for outcome analysis. The primary outcome was all-cause death. Discrimination and reclassification were calculated to assess the additional prognostic value of D-dimer when combined with established clinical risk factors and the Global Registry of Acute Coronary Events (GRACE) risk score. Results During a median follow-up of 652 days, a total of 194 deaths occurred. High D-dimer level, as defined by age-adjusted thresholds, was an independent predictor for all-cause death (hazard ratio:1.67, 95% confidence interval: 1.23–2.27, P=0.001). Addition of D-dimer level (high or low) significantly improved risk classification for death when combined with established clinical risk factors (net reclassification index [NRI]: 0.601, P<0.001; integrated discrimination improvement [IDI]: 0.011, P=0.046) and GRACE score (NRI: 0.618, P<0.001; IDI: 0.015, P=0.011). Conclusions In patients with MI treated by PCI, D-dimer elevation defined by age-adjusted thresholds was an independent predictor for adverse outcomes, and provided additional prognostic value when combined with clinical risk factors and GRACE score. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Chinese Academy of Medical Sciences