Impact of Primary Coronary Angioplasty Delay on Myocardial Salvage, Infarct Size, and Microvascular Damage in Patients with ST-Segment Elevation Myocardial Infarction: Insight From Cardiovascular Magnetic Resonance

OBJECTIVES: We investigated the extent and nature of myocardial damage by using cardiovascular magnetic resonance (CMR) in relation to different time-to-reperfusion intervals. Previous studies evaluating the influence of time to reperfusion on infarct size (IS) and myocardial salvage in patients with ST-segment elevation myocardial infarction (STEMI) have yielded conflicting results.

METHODS: Seventy patients with STEMI successfully treated with primary percutaneous coronary intervention within 12 h from symptom onset underwent CMR 3 +/- 2 days after hospital admission. Patients were subcategorized into 4 time-to-reperfusion (symptom onset to balloon) quartiles: 90 to 150 min (group II, n = 17), >150 to 360 min (group III, n = 17), and >360 min (group IV, n = 17). T2-weighted short tau inversion recovery and late gadolinium enhancement CMR were used to characterize reversible and irreversible myocardial injury (area at risk and IS, respectively); salvaged myocardium was defined as the normalized difference between extent of T2-weighted short tau inversion recovery and late gadolinium enhancement.

RESULTS: Shorter time-to-reperfusion (group I) was associated with smaller IS and microvascular obstruction and larger salvaged myocardium. Mean IS progressively increased overtime: 8% (group I), 11.7% (group II), 12.7% (group III), and 17.9% (group IV), p = 0.017; similarly, MVO was larger in patients reperfused later (0.5%, 1.5%, 3.7%, and 6.6%, respectively, p = 0.047). Accordingly, salvaged myocardium markedly decreased when reperfusion occurred >90 min of coronary occlusion (8.5%, 3.2%, 2.4%, and 2.1%, respectively, p = 0.004).

CONCLUSIONS: In patients with STEMI treated with primary percutaneous coronary intervention, time to reperfusion determines the extent of reversible and irreversible myocardial injury assessed by CMR. In particular, salvaged myocardium is markedly reduced when reperfusion occurs >90 min of coronary occlusion. Derek Anderson Authentic Jersey

PMID: 19942086

Posted in Invasive Imaging, Magnetic Resonance Imaging and tagged , , , , , , , .

2 Comments

  1. Also read associated editorial:
    Ischemic time: the new gold standard for ST-segment elevation myocardial infarction care.
    Smalling RW.
    J Am Coll Cardiol. 2009 Dec 1;54(23):2154-6

  2. Well designed study with important insights on the pathophysiology of reperfused myocardium. I found interesting that the extent of myocardial edema did not change significantly as time to reperfusion progressed.

    Another very interesting paper on the subject published simultaneously:
    Intramyocardial hemorrhage and microvascular obstruction after primary percutaneous coronary intervention.
    Beek AM, Nijveldt R, van Rossum AC.
    Int J Cardiovasc Imaging. January 2010;26(1):49–55
    PMID:

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