Abstract 1513: Short And Long-term Mortalitty In Chest-Pain Patients Ruling-in For Myocardial InfarctionI: STEMI Versus Non-STEMI In The Era Of A Troponin-based Definition For MI
Background: Several randomized clinical trials have demonstrated that patients (pts) with ST Elevation myocardial infarction (STEMI) have a higher short-term mortality than those with non-STEMI, but that long-term mortality is similar. More recent studies suggest that pts who are troponin positive (TnI+), but not meeting the older CKMB criteria for MI may also be at increased risk. However, there is little data examining outcomes differentiating these 3 MI populations using the current ACC/ESC definition for MI selected from a heterogeneous cohort of pts admitted from the emergency department.
Methods: Consecutive pts admitted for exclusion of myocardial ischemia underwent serial sampling of CK, CKMB, and TnI. MI was defined using ACC/ESC criteria. Pts were separated into 3 groups: STEMI (n=363; 22%), non-STEMI pts who met the prior CKMB criteria for MI (n=743; 46%), and non-STEMI pts who had MI based on TnI (+) alone (n=512; 32%) without meeting CKMB MI criteria. Demographic and clinical variables were compared among the three cohorts of patients, and 30 day and 1 year mortality were assessed.
Results: Over a 6 year period, 1,618 pts were diagnosed with MI. Co-morbidities and outcomes are shown below in the table⇓. Variables associated with worse outcomes were significantly more common in both groups of non-STEMI pts, particularly in the TnI (+) only pts. Thirty day mortality was similar and not significantly different among the 3 cohorts. However, at 1 year, mortality was a significant 68% higher in the 2 non-STEMI groups, despite having significantly lower peak CK (median 123 U/L for TnI (+) pts and 414 U/L for CKMB MI pts vs 1400 U/L for STEMI pts) and CKMB values (median 4 ng/ml for TnI (+) pts and 29 ng/ml for CKMB MI pts vs 140 ng/ml for STEMI pts) compared to STEMI pts.
Conclusions: All MI pts had similar 30 day mortality; however, at 1 yr pts with non-STEMI had a substantially increased mortality compared to STEMI pts.