Abstract 13671: Lymphocyte Depletion Post STEMI Confers Poor Prognosis: a Potential Role for T Lymphocytes and the Key Chemokine Fractalkine in Myocardial Ischemia/Reperfusion Injury

Introduction: We have previously shown depletion of circulating T lymphocytes (T cells) following primary percutaneous coronary intervention (PPCI) for STEMI. The goal of this study was to assess the prognostic significance of lymphocyte depletion, characterize the cells involved, and explore potential mechanisms. Methods and Results: Lymphocyte counts were retrospectively analyzed in 1377 consecutive STEMI patients treated with PPCI and discharged alive. Lymphopenia post PPCI was associated with lower survival at 3 years (79.3% vs 95.6%, lowest vs. highest tertile, p<0.001), independent of age and sex (hazard ratio 2.4, 95% CI 1.4-4.1). For cell characterization studies, arterial blood from 52 STEMI patients undergoing PPCI was sampled at 0, 15, 30, 90min and 24hrs after reperfusion. Absolute numbers of different leucocyte subpopulations were quantified by flow cytometry and are presented as % change ± SEM. Total T cells fell by -36±3% between 0 and 90 minutes (p<0.0001), before recovery by 24 hours. CD8...