Bates, Eric R.

Background Although retrospective analyses have revealed an association between survival and coronary angiography and angioplasty in patients with acute myocardial infarction complicated by cardiogenic shock, the degree to which bias in the selection of patients to undergo these procedures contributes to this observation remains unclear. Methods and Results We studied 2200 patients in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I) trial with acute myocardial infarction complicated by cardiogenic shock (systolic blood pressure <90 mm Hg for ≥1 hour) who survived ≥1 hour after the onset of shock to determine the influence of an aggressive strategy of early angiography (within 24 hours of shock onset) and coronary angioplasty or bypass surgery, if appropriate, on survival. Revascularization was not protocol mandated but was selected by the attending physicians. Shock was present on admission in 11% and developed after admission in 89% of shock patients. The 30-day mortality was 38% in the 406 patients who underwent early angiography and were referred within 24 hours for angioplasty (n=175), bypass surgery (n=36), angioplasty and bypass surgery (n=22), or neither (late or no revascularization, n=173) compared with 62% in the 1794 patients who did not ( P =.0001). However, there were important differences in the baseline characteristics of the two groups, including younger age (63 versus 68 years, P =.0001), less prior infarction (19% versus 27%, P =.001), and a shorter time to thrombolytic therapy (2.9 versus 3.2 hours, P =.0001) in patients treated with an aggressive strategy. Using multivariate logistic regression analysis to adjust for differences in baseline characteristics, an aggressive strategy was independently associated with reduced 30-day mortality (odds ratio, 0.43 [confidence interval, 0.34 to 0.54], P =.0001). Conclusions An aggressive strategy of early angiography (and revascularization when appropriate) is associated with a reduction in mortality in patients with acute myocardial infarction and cardiogenic shock who receive thrombolytic therapy.

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.