Lee, Kwang J.

Background: The aim of this study was to determine whether adding DE-CMR and/or TTE based parameters beyond known clinical factors provides incremental improvement of predicting long-term outcomes in STEMI patients who undergo acute reperfusion therapy. Methods and Results: One hundred twenty patients with first time STEMI who underwent PCI (74%), fibrinolysis (3%), and both (19%), were studied by both delayed enhancement cardiac magnetic resonance (DE-CMR) and transthoracic echocardiogram (TTE) during the acute phase of myocardial infarction. The primary endpoint was major adverse cardiac events (MACE). There were 28 events (6 deaths, 13 recurrent ischemia, and 9 heart failure) over a median follow-up of 4 years. We defined incremental increase in prognostic value by increase in Cox proportional hazards global chi square (χ 2 ) and/or increase in c-index with the addition of TTE and/or CMR parameters after adjusting for clinical variables. Among the clinical data, heart rate (HR: 1.02, p=0.047) and troponin (HR: 1.13, p=0.013) predicted MACE (χ 2 : 12.4, P=0.002; C index 0.69). After adjusting for these clinical factors, adding TTE parameters (left ventricular end systolic volume index [HR: 1.05, p<0.0001] and mitral valve deceleration time [HR: 0.99, p=0.036]), increased the global χ 2 to 24.6 and C index to 0.74 (p<0.0001). When CMR parameter (infarct size [HR: 2.92, p<0.0001]) was added to the clinical data alone, there was greater increase in global χ 2 to 36.8 and C index to 0.83 (p<0.0001). Addition of DE- CMR to clinical data combined with TTE measures showed significant incremental value with increased χ 2 difference of 17.6 (p<0.0001). There was no significant incremental value of adding TTE to clinical data combined with DE-CMR (p>0.05). Conclusion: DE-CMR provides significant incremental value for prognosticating adverse cardiac events over clinical data alone (or when in combination with TTE) in STEMI patients who undergo reperfusion therapy.