Faculty Bibliography

BACKGROUND: A multinational, randomized, placebo-controlled trial (Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy, PURSUIT) demonstrated that the platelet glycoprotein IIb/IIIa receptor antagonist eptifibatide reduced the incidence of death or myocardial infarction among patients with acute ischemic syndromes without ST-segment elevation. Because of expected differences in practice patterns, a prospectively planned analysis of outcomes as a function of regions of the world was performed. The current study provides a detailed assessment of eptifibatide among the subgroup of patients enrolled within the United States. METHODS AND RESULTS: Patients presenting with chest pain within the previous 24 hours and ischemic ECG changes or creatine kinase-MB elevation were eligible for enrollment. Of the 10 948 patients randomized worldwide, 4035 were enrolled within the United States. Patients were allocated to placebo or eptifibatide infusion for up to 72 to 96 hours. Other medical therapies and revascularization strategies were at the discretion of the treating physician. Eptifibatide reduced the rate of the primary end point of death or myocardial infarction by 30 days from 15.4% to 11.9% (P=0.003) among patients in the United States. The treatment effect was achieved early and maintained over a period of 6 months (18.9% versus 15.2%; P=0.004). Bleeding events were more common in patients receiving eptifibatide but were predominantly associated with invasive procedures. The magnitude of clinical benefit from eptifibatide was greater among patients in the United States than elsewhere in the world. CONCLUSIONS: Platelet glycoprotein IIb/IIIa receptor blockade with eptifibatide reduces the incidence of death or myocardial infarction among patients treated for acute ischemic syndromes without ST-segment elevation within the United States

OBJECTIVES: We wished to assess the profile and outcomes of patients with ventricular septal rupture (VSR) in the setting of cardiogenic shock (CS) complicating acute myocardial infarction (MI). BACKGROUND: Cardiogenic shock is often seen with VSR complicating acute MI. Despite surgical therapy, mortality in such patients is high. METHODS: We analyzed 939 patients enrolled in the SHOCK Trial Registry of CS in acute infarction, comparing 55 patients whose shock was associated with VSR with 884 patients who had predominant left ventricular failure. RESULTS: Rupture occurred a median 16 h after infarction. Patients with VSR tended to be older (p = 0.053), were more often female (p = 0.002) and less often had previous infarction (p < 0.001), diabetes mellitus (p = 0.015) or smoking history (p = 0.033). They also underwent right-heart catheterization, intra-aortic balloon pumping and bypass surgery significantly more often. Although patients with rupture had less severe coronary disease, their in-hospital mortality was higher (87% vs. 61%, p < 0.001). Surgical repair was performed in 31 patients with rupture (21 had concomitant bypass surgery); 6 (19%) survived. Of the 24 patients managed medically, only 1 survived. CONCLUSIONS: There is a high in-hospital mortality rate when CS develops as a result of VSR. Ventricular septal rupture may occur early after infarction, and women and the elderly may be more susceptible. Although the prognosis is poor, surgery remains the best therapeutic option in this setting

OBJECTIVES: We sought to determine the outcomes of patients with cardiogenic shock (CS) complicating non-ST-segment elevation acute myocardial infarction (MI). BACKGROUND: Such patients represent a high-risk (ST-segment depression) or low-risk (normal or nonspecific electrocardiographic findings) group for whom optimal therapy, particularly in the setting of shock, is unknown. METHODS: We assessed characteristics and outcomes of 881 patients with CS due to predominant left ventricular (LV) dysfunction in the SHOCK Trial Registry. RESULTS: Patients with non-ST-segment elevation MI (n = 152) were significantly older and had significantly more prior MI, heart failure, azotemia, bypass surgery, and peripheral vascular disease than patients with ST-elevation MI (n = 729). On average, the groups had similar in-hospital LV ejection fractions (approximately 30%), but patients with non-ST-elevation MI had a lower highest creatine kinase and were more likely to have triple-vessel disease. Among patients selected for coronary angiography, the left circumflex artery was the culprit vessel in 34.6% of non-ST-elevation versus 13.4% of ST-elevation MI patients (p = 0.001). Despite having more recurrent ischemia (25.7% vs. 17.4%, p = 0.058), non-ST-elevation patients underwent angiography less often (52.6% vs. 64.1%, p = 0.010). The proportion undergoing revascularization was similar (36.8% for non-ST-elevation vs. 41.9% ST-elevation MI, p = 0.277). In-hospital mortality also was similar in the two groups (62.5% for non-ST-elevation vs. 60.4% ST-elevation MI). After adjustment, ST-segment elevation MI did not independently predict in-hospital mortality (odds ratio, 1.30; 95% confidence interval, 0.83 to 2.02; p = 0.252). CONCLUSIONS: Patients with CS and non-ST-segment elevation MI have a higher-risk profile than shock patients with ST-segment elevation, but similar in-hospital mortality. More recurrent ischemia and less angiography represent opportunities for earlier intervention, and early reperfusion therapy for circumflex artery occlusion should be considered when non-ST-elevation MI causes CS

OBJECTIVES: The study examined whether antiplatelet treatment with eptifibatide affected the frequency and outcome of shock among patients in the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial who had acute coronary syndromes but not persistent ST-segment elevation. BACKGROUND: Preliminary reports suggest a salutary effect of antiplatelet agents when shock complicates acute myocardial infarction. METHODS: We analyzed the impact of antiplatelet treatment with eptifibatide on the frequency and outcome of cardiogenic shock developing after enrollment. PURSUIT was a double-blind, randomized trial that examined the efficacy of eptifibatide (180 microg/kg bolus + continuous infusion of 2.0 microg/kg/min for < or =96 h) versus placebo among patients who had acute coronary syndromes but not persistent ST-segment elevation. RESULTS: Shock developed in 2.5% of the 9,449 patients at a median (25th, 75th interquartiles) of 94.0 (38, 206) h. Death by 30 days occurred in 65.8% of shock patients. Patients who had acute myocardial infarction upon enrollment had a greater incidence of shock (2.9% vs. 2.1%, p = 0.01), developed shock earlier (40.2% <48 h vs. 20.9%, p = 0.001), and had higher 30-day mortality from shock (77.2% vs. 52.7%, p = 0.001). Randomization to eptifibatide did not affect the occurrence of shock (p = 0.71, adjusted odds ratio [OR] = 0.95, 95% confidence interval [CI] = 0.72-1.25). However, shock patients treated with eptifibatide had significantly reduced adjusted odds of 30-day death (p = 0.03, adjusted OR = 0.51, 95% CI = 0.28-0.94). CONCLUSIONS: Patients with shock treated with eptifibatide had significantly reduced adjusted odds of death, suggesting a salutary effect of antiplatelet therapy on shock. This finding warrants verification in specifically designed studies

OBJECTIVES: We sought to investigate the potential benefit of thrombolytic therapy (TT) and intra-aortic balloon pump counterpulsation (IABP) on in-hospital mortality rates of patients enrolled in a prospective, multi-center Registry of acute myocardial infarction (MI) complicated by cardiogenic shock (CS). BACKGROUND: Retrospective studies suggest that patients suffering from CS due to MI have lower in-hospital mortality rates when IABP support is added to TT. This hypothesis has not heretofore been examined prospectively in a study devoted to CS. METHODS: Of 1,190 patients enrolled at 36 participating centers, 884 patients had CS due to predominant left ventricular (LV) failure. Excluding 26 patients with IABP placed prior to shock onset and 2 patients with incomplete data, 856 patients were evaluated regarding TT and IABP utilization. Treatments, selected by local physicians, fell into four categories: no TT, no IABP (33%; n = 285); IABP only (33%; n = 279); TT only (15%; n = 132); and TT and IABP (19%; n = 160). RESULTS: Patients in CS treated with TT had a lower in-hospital mortality than those who did not receive TT (54% vs. 64%, p = 0.005), and those selected for IABP had a lower in-hospital mortality than those who did not receive IABP (50% vs. 72%, p < 0.0001). Furthermore, there was a significant difference in in-hospital mortality among the four treatment groups: TT + IABP (47%), IABP only (52%), TT only (63%), no TT, no IABP (77%) (p < 0.0001). Patients receiving early IABP (< or = 6 h after thrombolytic therapy, n = 72) had in-hospital mortality similar to those with late IABP (53% vs. 41%, n = 64, respectively, p = 0.172). Revascularization rates differed among the four groups: no TT, no IABP (18%); IABP only (70%); TT only (20%); TT and IABP (68%, p < 0.0001); this influenced in-hospital mortality significantly (39% with revascularization vs. 78% without revascularization, p < 0.0001). CONCLUSIONS: Treatment of patients in cardiogenic shock due to predominant LV failure with TT, IABP and revascularization by PTCA/CABG was associated with lower in-hospital mortality rates than standard medical therapy in this Registry. For hospitals without revascularization capability, a strategy of early TT and IABP followed by immediate transfer for PTCA or CABG may be appropriate. However, selection bias is evident and further investigation is required

OBJECTIVES: We sought to compare the characteristics and outcomes of patients with acute myocardial infarction (MI) and cardiogenic shock (CS) caused by rupture of the ventricular free wall or tamponade versus shock from other causes. BACKGROUND: Free-wall rupture is a recognized cause of mortality in patients with acute MI. Some of these patients present subacutely, which provides an opportunity for intervention. Recognition of factors that distinguish them from the overall shock cohort would be beneficial. METHODS: The international SHOCK Trial Registry enrolled patients concurrently with the randomized SHOCK Trial. Thirty-six centers consecutively enrolled all patients with suspected CS after MI, regardless of trial eligibility. RESULTS: Of the 1,048 patients studied, 28 (2.7%) had free-wall rupture or tamponade. These patients had less pulmonary edema, less diabetes, less prior MI, and less prior congestive heart failure (all p < 0.05). They more often had new Q waves in two or more leads (51.9% vs. 31.5%, p < 0.04), but MI location and time to shock onset after MI did not differ. Of patients with rupture or tamponade, 75% had pericardial effusions. No hemodynamic characteristics identified patients with rupture/tamponade. Most patients with rupture/tamponade had surgery and/or pericardiocentesis (27/28); their in-hospital survival rate was identical to that of the group overall (39.3%). Women and older patients with rupture/tamponade tended to survive intervention less often. CONCLUSIONS: Free-wall rupture and tamponade may present as CS after MI, and survival after intervention is similar to that of the overall shock cohort. All patients with CS after MI should have echocardiography in order to detect subacute rupture or tamponade and initiate appropriate interventions

OBJECTIVES: Our objective was to define the outcomes of patients with cardiogenic shock (CS) due to severe mitral regurgitation (MR) complicating acute myocardial infarction (AMI). BACKGROUND: Methods for early identification and optimal treatment of such patients have not been defined. METHODS: The SHOCK Trial Registry enrolled 1,190 patients with CS complicating AMI. We compared 1) the cohort with severe mitral regurgitation (MR, n = 98) to the cohort with predominant left ventricular failure (LVF, n = 879), and 2) the MR patients who underwent valve surgery (n = 43) to those who did not (n = 51). RESULTS: Shock developed early after MI in both the MR (median 12.8 h) and LVF (median 6.2 h) cohorts. The MR patients were more often female (52% vs. 37%, p = 0.004) and less likely to have ST elevation at shock diagnosis (41% vs. 63%, p < 0.001). The MR index MI was more frequently inferior (55% vs. 44%, p = 0.039) or posterior (32% vs. 17%, p = 0.002) than that of LVF and much less frequently anterior (34% vs. 59%, p < 0.001). Despite having higher mean LVEF (0.37 vs. 0.30, p = 0.001) the MR cohort had similar in-hospital mortality (55% vs. 61%, p = 0.277). The majority of MR patients did not undergo mitral valve surgery. Those undergoing surgery exhibited higher mean LVEF than those not undergoing surgery; nevertheless, 39% died in hospital. CONCLUSIONS: The data highlight opportunities for early identification and intervention to potentially decrease the devastating mortality and morbidity of severe post-myocardial infarction MR

OBJECTIVES: We sought to examine the role of diabetes mellitus in cardiogenic shock (CS) complicating acute myocardial infarction (AMI) in the SHOCK Trial Registry. BACKGROUND: The characteristics, outcomes and optimal treatment of diabetic patients with CS complicating AMI have not been well described. METHODS: Baseline characteristics, clinical and hemodynamic measures, treatment variables, shock etiologies and comorbid conditions were compared for 379 diabetic and 784 nondiabetic patients. Logistic regression was used to examine the association between diabetes and in-hospital mortality, after adjustment for baseline differences. RESULTS: Diabetics were less likely than nondiabetics to undergo thrombolysis (28% vs. 37%; p = 0.002) or attempted revascularization (40% vs. 49%; p = 0.008). The survival benefit for diabetics selected for percutaneous or surgical revascularization (55% vs. 19% without revascularization) was similar to that for nondiabetics (59% vs. 25%). Overall unadjusted in-hospital mortality was significantly higher for diabetics (67% vs. 58%; p = 0.007), but diabetes was only a borderline predictor of mortality after adjustment for baseline and treatment differences (odds ratio for death, 1.36; 95% confidence interval, 1.00 to 1.84; p = 0.051). CONCLUSIONS: Diabetics with CS complicating AMI have a higher-risk profile at baseline, but after adjustment, diabetics have an in-hospital survival rate that is only marginally lower than that of nondiabetics. Diabetics who undergo revascularization derive a survival benefit similar to that of nondiabetics

OBJECTIVES: We sought to examine the implications of the timing of onset of cardiogenic shock (CS) after acute myocardial infarction (MI). BACKGROUND: Little information is available about the relationships between timing, clinical substrate, management and outcomes of shock. METHODS: The multinational SHOCK Trial Registry enrolled MI patients with CS from 1993 to 1997. Cardiogenic shock was predominantly attributable to left ventricular (LV) failure in 815 Registry patients for whom temporal data were available. We examined factors related to the timing of shock onset and the relation of temporal onset to in-hospital outcomes. RESULTS: Overall, shock developed a median of 6.2 h after MI symptom onset. Shock onset varied by culprit artery: left main, median 1.7 h; right, 3.5 h; circumflex, 3.9 h; left anterior descending (LAD), 11.0 h; saphenous vein graft, 10.9 h (p = 0.025). Early shock (< 24 h) occurred in 74.1% and was associated with chest pain at shock onset, ST-segment elevation in two or more leads, multiple infarct locations, inferior MI, left main disease and smoking. Late shock (> or = 24 h) was associated with recurrent ischemia, Q waves in two or more leads and LAD culprit vessel. Mortality was higher in patients with early versus late shock (62.6% vs. 53.6%, p = 0.022). CONCLUSIONS: Shock onset after acute MI occurred within 24 h in 74% of the patients with predominant LV failure. Mortality was slightly higher in patients developing shock early rather than later. Many factors influence when shock develops, which has implications for its management