Abstract 15580: Persistence of the Effects of Time-to-Reperfusion on Myocardial Damage at 6 Months of Follow-up: Cardiovascular Magnetic Resonance Insights
Objectives: In patients with ST-segment elevation myocardial infarction (STEMI) few studies have analyzed if time-to-reperfusion maintains its influence on myocardial damage far from the acute event. The aim of our study is to evaluate how time from symptoms onset to balloon (total ischemic time) weigh on the extent of infarct size (IS), microvascular obstruction (MVO), and myocardial remodeling at 6 months of follow-up after a STEMI as assessed by Cardiovascular Magnetic Resonance (CMR).
Methods: We enrolled 90 consecutive patients with STEMI, successfully treated by primary coronary angioplasty, who underwent CMR 3+2 days after myocardial infarction and at 6 months from it. Patients were divided into 4 time-to-reperfusion intervals quartiles: <90 minutes (group I, 20 patients), >90–160 minutes (group II, 25 patients), >160–360 minutes (group III, 23 patients), >360 minutes (group IV, 22 patients). T2-weighted short tau inversion recovery and late gadolinium enhancement sequences were used to characterize reversible and irreversible myocardial injury (area at risk and IS, respectively). Myocardial end-diastolic and end-systolic volumes were also analyzed.
Results: Mean IS at 6 months progressively increased overtime: 4.8% (group I), 7.4% (group II), 12.5% (group III), and 17.5% (group IV)(p=0.001). Patients later reperfused showed a higher persistence of MVO at 6 months (14.3%, 18%, 20%, 38.5%, respectively, p=0.019). Myocardial remodeling (increase of end-systolic volume >15%) was frequently observed in the last group (6.2%, 23.5%, 25%, 43.8%, p=0.038). The hyper-intense signal in T2-STIR sequences disappeared at 6 months, confirming the acute feature of myocardial oedema in acute myocardial infarction.
Conclusions: In STEMI patients, time-to-reperfusion is a determining factor myocardial damage not only in the acute phase, as we have already demonstrated, but also in the follow-up. CMR is an accurate technique to evaluate myocardial injury after STEMI and it allows a suitable prognostic stratification of patients.
- © 2010 by American Heart Association, Inc.