Abstract 14922: Extra-Hospital Delays Correlate More Strongly With Myocardial Damage in Stemi, Evaluated by Cardiac Magnetic Resonance
Introduction: Current STEMI guidelines use intra-hospital time as time reference for performing PCI (90 minutes from first medical contact). However, this time may not be the one that better reflects myocardial damage.
Hypothesis: The aim of our study was to identify, in STEMI patients, the best time delay parameter to reproduce the nature and extent of myocardial damage as assessed by cardiovascular magnetic resonance (CMR). We also evaluated the ratio between microvascular obstruction (MVO, hypoenhancement) and the infarct size (IS, hyper-enhancement) as a possible index of irreversible myocardial damage and its correlation with time delays.
Methods: We enrolled 90 patients with STEMI successfully treated with primary PCI within 12 hours from symptom onset, who underwent CMR 3±2 days after hospital admission and at 6 months. Time between symptoms onset to balloon (total time, pain to balloon), symptoms onset to first medical contact (extra-hospital time, pain to FMC) and first medical contact to balloon (intra-hospital time, FMC to balloon) were all recorded. Area at risk, infarct size (IS), ejection fraction (EF),microvascular obstruction (MVO), MVO/IS were assessed. For statistical analysis we used Pearson’s correlation test .
Results: Pain to balloon was the time with the strongest correlation with the infarct size in acute (r = 0.68, p<0.0001), and after 6 months (r = 0.50 p = 0.02) compared to pain to FMC and FMC to balloon. Only pain to balloon correlated with the EF at 6 months (r = -0.36, p = 0.006). Both saved myocardium (area at risk - IS) and MVO correlated significantly with Pain to FMC (r = -0.46, p = 0.003 and r = 0.413 p =0.006, respectively) compared to the other times. Pain to FMC and pain to balloon had strongest correlation with MVO/IS (r= 0,814, p = 0.0001 and r=0.520, p =0.0001, respectively).
Conclusions: In patients with STEMI, total and extra-hospital times are more representative of myocardial damage than intra-hospital time. Particularly, the ratio between MVO and IS can be an index of irreversible damage and is strongly influenced by time delays to PCI.
- © 2013 by American Heart Association, Inc.