Rapid complete reversal of systemic hypoperfusion after intra-aortic balloon pump counterpulsation and survival in cardiogenic shock complicating an acute myocardial infarction.

BACKGROUND: In patients with cardiogenic shock (CS) complicating an acute myocardial infarction, a strategy of early revascularization (ERV) versus initial medical stabilization (IMS) improves survival. Intra-aortic balloon counterpulsation (IABC) provides hemodynamic support and facilitates coronary angiography and revascularization in CS patients. METHODS AND RESULTS: We evaluated 499 patients with record of systemic hypoperfusion status as an early response to IABC from the SHOCK trial (n = 185) and registry (n = 314) to determine the association between rapid complete reversal of systemic hypoperfusion (CRH) after 30 minutes of IABC and in-hospital, 30-day and 1-year mortality. Rapid complete reversal of systemic hypoperfusion was highly associated with lower in-hospital mortality (29% versus 65%, P < .001) in all patients. In the SHOCK trial, among patients assigned to ERV versus IMS, 30-day mortality was 26% versus 29%, respectively, with CRH and 61% versus 81%, respectively, without CRH after commencing IABC. The corresponding 1-year mortality rates were 35% versus 52% for ERV and 69% versus 87% for IMS (interaction P ≥ .25 at both time points). After adjusting for important correlates of outcome (left ventricular ejection fraction, age, and randomization to ERV), a significant association remained between CRH and registry and trial in-hospital mortality (odds ratio 0.23, 95% CI 0.14-0.39, P < .001) and trial 1-year mortality (odds ratio .28, 95% CI 0.12-0.67, P < .001). CONCLUSIONS: In CS patients, CRH after commencing IABC was independently associated with improved in-hospital, 30-day and 1-year survival regardless of early revascularization. In CS patients, CRH with IABC is an important early prognostic feature.

Early revascularization is beneficial across all ages and a wide spectrum of cardiogenic shock severity: A pooled analysis of trials.

BACKGROUND: A pooled analysis in cardiogenic shock due to acute coronary syndromes is desirable to assess the effect of early revascularization (ERV) across all ages and a wide spectrum of disease severity. METHODS: Only two randomized controlled trials (RCT), i.e. SMASH and SHOCK, met the inclusion criteria and were combined for a pooled analysis using individual patient data (n = 348). RESULTS: SMASH patients (n = 54, 16%) had more severe disease than SHOCK patients (n = 294, 84%). After adjustment for age, anoxic brain damage, non-inferior myocardial infarction, prior coronary artery bypass graft surgery, renal failure, systolic blood pressure, and selection for coronary angiography, one-year mortality was similar (relative risk SHOCK versus SMASH 0.87, 95% CI: 0.61-1.25). Relative risk of one-year death for ERV versus initial medical stabilization was 0.82 (95% CI: 0.70-0.96). There was no significant difference in the treatment effect by age (≤75 years relative risk at one year 0.79, 95% CI: 0.63-0.99; > 75 years relative risk at one year 0.93, 95% CI: 0.56-1.53; interaction P = 0.10). CONCLUSIONS: Only two RCT have been published emphasizing the difficulty of enrolling critically ill patients. Despite large differences in shock severity, ERV benefit is similar across all ages and not significantly different for the elderly.

Cardiogenic shock without flow-limiting angiographic coronary artery disease: (from the Should We Emergently Revascularize Occluded Coronary Arteries for Cardiogenic Shock Trial and Registry).

Myocardial infarction often develops when thrombosis occurs at lesions that have not previously been flow limiting. However, the development of cardiogenic shock complicating acute myocardial infarction in such circumstances has received little attention. The characteristics of 15 patients with cardiogenic shock who had no flow-limiting angiographic stenoses were compared with those of 767 patients with > or =1 stenosis who were enrolled in the Should We Emergently Revascularize Occluded Coronary Arteries for Cardiogenic Shock (SHOCK) trial and registry. Compared with patients with > or =1 flow-limiting stenosis, patients with no flow-limiting stenoses were less likely to have pulmonary edema on chest x-ray (29% vs 62%, p = 0.008) and to be white (53% vs 82%, p = 0.011), and they had lower median highest creatine kinase levels (702 vs 2,731 U/L, p = 0.018). For SHOCK trial patients, 1-year survival was 49% for patients with > or =1 flow-limiting stenosis and 71% for those with no flow-limiting stenoses (p = 0.268). In conclusion, patients with cardiogenic shock without flow-limiting stenosis have different characteristics, and potentially disease mechanisms, and they do not require revascularization.

Echocardiographic and angiographic correlations in patients with cardiogenic shock secondary to acute myocardial infarction.

In patients with cardiogenic shock (CS) complicating acute myocardial infarction, echocardiographic and angiographic findings are used to aid diagnosis, determine prognosis, and guide management. The purpose of this analysis from the Should we emergently revascularize Occluded Coronary arteries for Cardiogenic ShocK (SHOCK) trial is to identify relations between the angiographic and echocardiographic features of patients with CS. Such an analysis of the correlations between echocardiographic and angiographic findings in patients with CS may provide insights into the etiology and treatment of CS. In 302 randomized patients, an echocardiogram and an angiogram before revascularization were available in 127 patients. Although the median ejection fraction derived by echocardiography and left ventricular angiography was identical (30%), the positive correlation was weak (R2 = 0.209, p = 0.019). Patients with a larger number of diseased vessels had worse mitral regurgitation (MR) by echocardiography (p = 0.005). There was a significant but weak association between left ventricular angiographic MR grade and echocardiographic MR severity (R2 = 0.162, p = 0.015), but there was no association between culprit vessel and degree of MR. In conclusion, worse coronary artery disease is associated with more severe MR. Echocardiography and angiography are valuable and result in similar estimated ejection fractions in a large cohort, but there is wide variation between the techniques in patients.

Stroke Prevention Trial in Sickle Cell Anemia (STOP): extended follow-up and final results.

The Stroke Prevention Trial in Sickle Cell Anemia (STOP) was a randomized trial to evaluate whether chronic transfusion could prevent initial stroke in children with sickle-cell anemia at high risk as determined by transcranial Doppler (TCD). The trial demonstrated a large benefit of transfusion and was halted early. After termination of the trial, patients participated in a post-trial follow-up study. More patients in the transfusion group (70%) elected transfusion for primary stroke prevention compared with those on standard care (45%). Six patients with persistently abnormal TCD results developed stroke. A minority with initially abnormal TCD results remained stroke-free without transfusion. Except for lower baseline and follow-up TCD velocities compared with those with stroke, no predictive features of this apparent lower-risk subgroup could be determined. TCD results at last testing in 108 patients that did not have stroke were: normal (44.4%), conditional (26.9%), abnormal (22.2%), and inadequate (6.5%). Patients on transfusion were more likely to have normal TCD results. Transfusion resulted in iron overload and alloimmunization, but no infection. The study provides new information on acceptance rates and long-term effects of transfusion. Persistent TCD elevation signals ongoing stroke risk. Reduction in TCD results over time without transfusion is observed in some patients and requires further study.

An early revascularization strategy is associated with a survival benefit for diabetic patients in cardiogenic shock after acute myocardial infarction.

BACKGROUND: The role of diabetes mellitus (DM) in cardiogenic shock (CS) complicating an acute myocardial infarction (AMI) is not well understood. Previous studies have reported an in-hospital mortality rate for patients with DM and CS of about 60%. OBJECTIVES: This study compares the 1-year mortality rates of patients with DM and those without (NDM) and evaluates early revascularization (ERV) compared with initial medical stabilization (IMS) in patients with DM and CS. METHODS: Baseline characteristics, clinical and hemodynamic measures, and management were compared for 90 patients (31%) with DM and 198 with NDM (69%) who were randomized to ERV or IMS in the SHOCK Trial. RESULTS: When compared with NDM, patients with DM were of similar age but had higher rates of prior MI (44.4 vs. 27.8%, p = 0.007) and hypertension (56.2 vs. 42.5%, p = 0.04). The DM group had a lower rate of fibrinolytic therapy (44.4 vs. 60.1%, p = 0.02). In patients randomized to ERV, patients with DM had a higher rate of coronary artery bypass grafting (CABG) (50.0 vs. 30.9%, p = 0.03) despite similar rates of triple-vessel disease. The 1-year mortality rates in both groups were equivalent (58.9%). One-year mortality was not associated with diabetes (hazard ratio [HR] 1.02, 95% CI, 0.73-1.42, p = 0.91). The benefit of an ERV strategy was similar (HR [DM] 0.62; HR [NDM] 0.75, p = 0.58). Even after adjusting for the imbalance in CABG rates, 1-year mortality was not associated with DM. CONCLUSION: Diabetes mellitus is not a predictor of 1-year mortality in CS after AMI. The benefit from an ERV strategy is similar for DM and NDM. The management strategies and influence of DM on mortality in CS deserve further evaluation.

Restrictive physiology in cardiogenic shock: observations from echocardiography.

BACKGROUND: Left ventricular diastolic abnormalities are associated with adverse outcome in myocardial infarction. Intra-aortic balloon pump (IABP) support is associated with improved diastolic filling. In the SHOCK trial and registry, average left ventricular ejection fraction (LVEF) was approximately 30%, higher than expected based on the classic paradigm. We hypothesized that restrictive physiology plays a role in cardiogenic shock (CS). METHODS: Echocardiograms obtained during the SHOCK trial within 24 hours of randomization were centrally interpreted. Patients with quantifiable mitral E-wave deceleration time were included (n = 64). The restrictive filling pattern was defined as deceleration time < 140 milliseconds. RESULTS: The restrictive pattern was seen in 60.9% of patients studied. Patients with this pattern had lower LVEF (31.1% vs 39.0%, P = .02) and higher wall motion score index (2.1 vs 1.8, P = .05). Patients with restriction were more likely to have IABP support during echocardiography (73.7% vs 43.5%, P = .03). There was no difference with and without restriction in demographic and hemodynamic variables or in mitral regurgitation degree or extent of coronary disease. The restrictive pattern had positive predictive value of 80% for pulmonary capillary wedge pressure > or = 20 mm Hg. Thirty-day survival was 53.9% with restriction versus 68.0% without restriction, P = .31. There was no difference in New York Heart Association class at 1 year between groups. CONCLUSIONS: The restrictive filling pattern is common in patients with CS, which may suggest that diastolic dysfunction contributes to CS pathogenesis. Patients with the restrictive pattern had lower LVEF despite IABP support. An association between the restrictive pattern and mortality was not demonstrated; power was limited by sample size.

Emergency revascularization in patients with cardiogenic shock on admission: a report from the SHOCK trial and registry.

AIMS: To determine clinical correlates and optimal treatment strategy in patients with cardiogenic shock (CS) on admission. METHODS AND RESULTS: In SHould we emergently revascularize Occluded Coronaries in cardiogenic shocK? (SHOCK) trial and registry patients with left ventricular (LV) dysfunction (n=1053), CS on admission occurred in 26% of directly admitted patients (n=166/627). Time from myocardial infarction to CS was shorter, initial haemodynamic profile poorer, and aggressive treatment less frequent in CS on admission than in delayed CS patients. CS on admission patients constituted a smaller relative proportion (11%) of the transferred (n=48/426) when compared with the directly admitted cohort (P<0.001). In-hospital mortality was higher (75 vs. 56%; P<0.001) with more rapid death (24-h mortality 40 vs. 17%; P<0.001) in CS on admission than in delayed CS patients. Emergency revascularization reduced in-hospital mortality in CS on admission (60 vs. 82%; P=0.001) and in delayed CS patients similarly (46 vs. 62%; P<0.001; interaction P=0.25). After adjustment for clinical differences, CS on admission was an independent predictor of in-hospital mortality (P=0.008). CONCLUSION: CS on admission patients have a worse outcome but benefit equally from emergency revascularization as delayed CS patients, emphasizing the need for rapid and direct access of CS on admission patients to facilities providing this care.