Faculty Bibliography

BACKGROUND: The SHOCK Registry prospectively enrolled patients with cardiogenic shock complicating acute myocardial infarction in 36 multinational centers. METHODS: Cardiogenic shock was predominantly attributable to left ventricular pump failure in 884 patients. Of these, 276 underwent percutaneous coronary intervention (PCI) after shock onset and are the subject of this report. RESULTS: The majority (78%) of patients undergoing angiography had multivessel disease. As the number of diseased arteries rose from 1 to 3, mortality rates rose from 34.2% to 51.2%. Patients who underwent PCI had lower in-hospital mortality rates than did patients treated medically (46.4% vs 78.0%, P < .001), even after adjustment for patient differences and survival bias (P = .037). Before PCI, the culprit artery was occluded (Thrombolysis In Myocardial Infarction grade 0 or 1 flow) in 76.3%. After PCI, the in-hospital mortality rate was 33.3% if reperfusion was complete (grade 3 flow), 50.0% with incomplete reperfusion (grade 2 flow), and 85.7% with absent reperfusion (grade 0 or 1 flow) (P < .001). CONCLUSIONS: This prospective, multicenter registry of patients with acute myocardial infarction complicated by cardiogenic shock is consistent with a reduction in mortality rates as the result of percutaneous coronary revascularization. Coronary artery patency was an important predictor of outcome. Measures to promote early and rapid reperfusion appear critically important in improving the otherwise poor outcome associated with cardiogenic shock

Recently, it has been demonstrated in multiple clinical research studies that non-Q-wave myocardial infarction shares many of the features of unstable angina pectoris and that both diseases initially are managed similarly. Important new antiplatelet drugs (glycoprotein IIb-IIIa inhibitors) and antithrombin agents (low-molecular-weight heparin) are currently recommended for patients with unstable angina pectoris/non-ST-segment elevation MI who are at high or intermediate risk on the basis of symptoms, electrocardiographic findings, and the presence or absence of serum markers (eg, troponin I, troponin T, and creatine kinase-MB). This review provides important information concerning the results of clinical studies of glycoprotein IIb-IIIa inhibitors (tirofiban hydrochloride and eptifibatide) when used with unfractionated heparin in patients with this syndrome or with low-molecular weight heparin (enoxaparin sodium) in similar patients. The Thrombolysis in Myocardial Infarction IIIB, Veterans Affairs Non-Q-Wave Infarction Studies in Hospital, and Fast Revascularization During Instability in Coronary Artery Disease II studies evaluating a conservative, ischemia-guided approach vs an early aggressive approach to such patients are presented, with a practical algorithm for treating such patients

AIMS: We analysed time trends in patient characteristics, management, and outcomes of cardiogenic shock complicating acute myocardial infarction in the international, prospective SHOCK Trial Registry and pre-study Registry. BACKGROUND: Despite therapeutic advances in its management, the incidence and high mortality of this complication has remained unchanged for decades. However, in recent years mortality was reported to decrease in one community concomitant with increasing use of revascularization. METHODS: Thirty-six centres registered 1380 patients with suspected cardiogenic shock complicating acute myocardial infarction from January 1992 to August 1997. Patient and myocardial infarction characteristics, haemodynamics, medications, procedure use, and vital status at discharge were recorded. RESULTS: In all, 79% of patients had shock due to predominant pump failure (non-mechanical aetiology). The aetiology, patient profile, and clinical characteristics of cardiogenic shock did not differ over time, except for increases in the incidence of prior bypass surgery (P=0.054) and transfers to tertiary centres (P=0.008). In all, 44% underwent revascularization (n=485), with angioplasty performed more often than bypass surgery (69% vs 31%). The revascularization rate increased over time (P=0.006) with a significant decrease in the time to revascularization (P=0.033). The use of Swan-Ganz catheterization decreased over time (P=0.018), as did the mean length of hospitalization (P=0.034). Overall in-hospital mortality was high (63%) but decreased over time in all patients (P=0.004) and those with pump failure (P=0.018). Mortality was lower for patients who underwent revascularization compared to those who were not revascularized (41% vs 79%, P<0.001). CONCLUSIONS: Cardiogenic shock complicating acute myocardial infarction is associated with a high mortality rate, but mortality decreased significantly from 1992 to 1997. This partly reflects the greater use of revascularization, which was associated with better outcomes. The reported international trend towards shorter admissions for myocardial infarction was also observed in this cohort

CONTEXT: Cardiogenic shock (CS) is the leading cause of death for patients hospitalized with acute myocardial infarction (AMI). OBJECTIVE: To assess the effect of early revascularization (ERV) on 1-year survival for patients with AMI complicated by CS. DESIGN: The SHOCK (Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock) Trial, an unblinded, randomized controlled trial from April 1993 through November 1998. SETTING: Thirty-six referral centers with angioplasty and cardiac surgery facilities. PATIENTS: Three hundred two patients with AMI and CS due to predominant left ventricular failure who met specified clinical and hemodynamic criteria. INTERVENTIONS: Patients were randomly assigned to an initial medical stabilization (IMS; n = 150) group, which included thrombolysis (63% of patients), intra-aortic balloon counterpulsation (86%), and subsequent revascularization (25%), or to an ERV group (n = 152), which mandated revascularization within 6 hours of randomization and included angioplasty (55%) and coronary artery bypass graft surgery (38%). MAIN OUTCOME MEASURES: All-cause mortality and functional status at 1 year, compared between the ERV and IMS groups. RESULTS: One-year survival was 46.7% for patients in the ERV group compared with 33.6% in the IMS group (absolute difference in survival, 13.2%; 95% confidence interval [CI], 2.2%-24.1%; P<.03; relative risk for death, 0.72; 95% CI, 0.54-0.95). Of the 10 prespecified subgroup analyses, only age (<75 vs >/= 75 years) interacted significantly (P<.03) with treatment in that treatment benefit was apparent only for patients younger than 75 years (51.6% survival in ERV group vs 33.3% in IMS group). Eighty-three percent of 1-year survivors (85% of ERV group and 80% of IMS group) were in New York Heart Association class I or II. CONCLUSIONS: For patients with AMI complicated by CS, ERV resulted in improved 1-year survival. We recommend rapid transfer of patients with AMI complicated by CS, particularly those younger than 75 years, to medical centers capable of providing early angiography and revascularization procedures

OBJECTIVES: We sought to investigate the effect of angiotensin-converting enzyme (ACE) inhibition <9 h after myocardial infarction (MI) on left ventricular (LV) dilation in patients receiving thrombolysis. BACKGROUND: The ACE inhibitors reduce mortality after MI. Attenuation of LV dilation has been suggested as an important mechanism. METHODS: The data of 845 patients with three-month echocardiographic follow-up after MI were combined from three randomized, double-blind, placebo-controlled studies. The criteria for these studies included: 1) thrombolytic therapy; 2) ACE inhibition within 6 to 9 h; and 3) evaluation of LV dilation as the primary objective. RESULTS: The ACE inhibitor was started 3.2+/-1.7 h after the patients' first (mainly, 85%) anterior MI. After three months, LV dilation was not significantly attenuated by very early treatment with an ACE inhibitor. The diastolic volume index was attenuated by 0.5 ml/m2 (95% confidence interval [CI] -1.5 to 2.5, p = 0.61), and the systolic volume index by 0.5 ml/m2 (95% CI -1.0 to 1.9, p = 0.50). Subgroup analysis demonstrated that LV dilation was significantly attenuated by ACE inhibitor treatment for patients in whom reperfusion failed. In contrast, LV dilation was almost unaffected by ACE inhibitor treatment in successfully reperfused patients. CONCLUSIONS: We could not demonstrate attenuation of LV dilation in patients receiving thrombolysis by ACE inhibitor treatment within 6 to 9 h after MI. We speculate that very early treatment with an ACE inhibitor has a beneficial effect on LV remodeling only in patients in whom reperfusion failed. Other mechanisms may be responsible for the beneficial effects of ACE inhibitors in successfully reperfused patients after MI

AIMS: We used the GUSTO-I and GUSTO-III databases to evaluate our performance in treating cardiogenic shock patients over much of the 1990s. METHODS AND RESULTS: GUSTO-I (1990-1993) and GUSTO-III (1995-1997) prospectively identified all patients with cardiogenic shock complicating acute myocardial infarction. Demographics, clinical presentation and outcomes for cardiogenic shock patients in the two trials were compared. Only patients enrolled with cardiogenic shock in countries common to both trials were included in these analysis. The 695 patients with cardiogenic shock in GUSTO-III were compared with the 2814 patients with cardiogenic shock in GUSTO-I. GUSTO-III patients were older (P=0.0001) and more likely to be diabetic (P=0.009) and hypertensive (P=0.025). They had a higher Killip class (P=0.002) and significantly greater index anterior infarction than cardiogenic shock patients enrolled in GUSTO-I. Time to treatment, presentation heart rate, and diastolic blood pressure were similar; however, systolic blood pressure at presentation was higher among GUSTO-III patients (P=0.002). Rates of coronary angiography, pulmonary artery catheterization, and mechanical ventilation declined in GUSTO-III compared with GUSTO-I (P=0.001); rates of angioplasty and bypass surgery were similar. Cardiogenic shock mortality in GUSTO-III was significantly higher than in GUSTO-I (62 vs 54%, P=0.001), as were rates of reinfarction (14 vs 11%, P=0.013) and recurrent ischaemia (35 vs 27%, P=0.00001). Mortality at non-U.S. sites (68 and 64%) was higher than at U.S. sites (53 and 50%) in both GUSTO-I and GUSTO-III studies, respectively. Angioplasty, bypass surgery, and balloon pump rates were lower for non-U.S. patients. CONCLUSIONS: Cardiogenic shock continues to be associated with high mortality in thrombolytic-treated patients. Lower mortality observed in the U.S.A. supports consideration for percutaneous and surgical revascularization

BACKGROUND: New recombinant plasminogen activators have been developed to simulate the fibrinolytic action of the physiological serine protease tissue plasminogen activator (alteplase, t-PA), and have prolonged half-life features permitting bolus administration. One such activator, reteplase (r-PA), was compared with t-PA in the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO)-III Trial. METHODS AND RESULTS: At 1-year follow-up, survival status was ascertained in 97.4% of the 15 059 patients enrolled in the GUSTO-III trial. At 1 year, the mortality rate for the t-PA-assigned group was 11.06%, and for r-PA it was 11.20% (P:=0. 77). The absolute mortality difference of 0.14% has 95% CIs of -1. 21% to 0.93%. There were no significant differences in outcome by intention-to-treat for the 2 different plasminogen activators in the prespecified groups (age, infarct location, time-to-treatment). The absolute difference in mortality rates between t-PA and r-PA progressively narrowed over the predetermined observation times after random assignment; it was 0.31% at 24 hours, 0.26% at 7 days, 0.23% at 30 days, and 0.14% at 1 year. Of note, mortality rate in the trial between 30 days and 1 year in 13 883 patients was 4.02% and did not differ between the treatment groups. However, this mortality rate was substantially greater than in GUSTO-I, in which mortality rate for t-PA versus streptokinase between 30 days and 1-year was 2.97% (heart rate 1.36, 95% CI 1.23, 1.50, P:<0.001). CONCLUSIONS: The r-PA and t-PA strategies yielded similar survival outcomes after 30 days in this trial. The increase in mortality rate during extended follow-up compared with previous trials may reflect higher-risk patients and highlights the need for improved secondary prevention strategies

BACKGROUND: Controversy exists regarding the timing of thrombolytic administration and rupture rate. METHODS: Hospital records at St. Luke's-Roosevelt Hospital of the 4 study patients were reviewed and compared with those of 41 patients from a group of 537 patients concurrently admitted with a diagnosis of myocardial infarction (MI). RESULTS: Four patients experienced ventricular free wall rupture after having a MI between November 17, 1993, and July 28, 1995. All received tissue plasminogen activator. In 1 patient, pericardial effusion associated with a pseudoaneurysm was discovered in the operating room. The 3 others developed clinical pericardial tamponade before surgery. All 4 patients survived and left the hospital on postoperative days 10, 11, 11, and 82, respectively. During this same time period, 537 patients were admitted with MI, 41 of whom died; the study's 4 patients were compared with these 41. CONCLUSIONS: These data demonstrate that rupture of the ventricular free wall can occur early after thrombolytic therapy and may have a subacute course. Prompt diagnosis and surgery offer excellent chances of surviving this fatal condition