Cardiogenic Shock in Patients With Acute Ischemic Syndromes With and Without ST-Segment Elevation

BACKGROUND: Cardiogenic shock is usually considered a sequela of ST-segment elevation myocardial infarction. There are limited prospective data on the incidence and significance of shock in non-ST-segment elevation patients. This study assessed the incidence and outcomes of cardiogenic shock developing after enrollment among patients with and without ST-segment elevation in the Global Use of Strategies To Open Occluded Coronary Arteries (GUSTO)-IIb trial. METHODS AND RESULTS: Among 12,084 patients in GUSTO-IIb who did not present with cardiogenic shock, 4092 (34%) had and 7991 (66%) did not have ST-segment elevation on the enrollment ECG. Cardiogenic shock developed in 4.2% of ST-segment elevation patients compared with 2.5% of patients without ST-segment elevation (odds ratio, 0. 581; 95% CI, 0.472 to 0.715; P<0.001). Shock developed significantly later among patients without ST-segment elevation. There were significant differences in baseline characteristics between shock patients with and without ST-segment elevation: Patients without ST-segment elevation were older, more frequently had diabetes mellitus and 3-vessel disease, but had less TIMI grade 0 flow at angiography. Regardless of the initial ECG, mortality was high: 63% among patients with ST-segment elevation and 73% in those without ST-segment elevation. CONCLUSIONS: Cardiogenic shock occurs in the setting of acute ischemic syndromes regardless of whether ST-segment elevation is present. The incidence, patient characteristics, timing, clinical course, and angiographic findings differ between the 2 groups. Mortality from cardiogenic shock is similarly high among patients with and without ST-segment elevation.