The effects of temporary mechanical circulatory support with a microaxial flow pump on mortality among patients with ST-segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock remains unclear. In an international, multicenter, randomized trial, we assigned patients with STEMI and cardiogenic shock to receive a microaxial flow pump (Impella CP) plus standard care or standard care alone. The primary end point was death from any cause at 180 days. A composite safety end point was severe bleeding, limb ischemia, hemolysis, device failure, or worsening aortic regurgitation. A total of 360 patients underwent randomization, of whom 355 were included in the final analysis (179 in the microaxial-flow-pump group and 176 in the standard-care group). The median age of the patients was 67 years, and 79.2% were men. Death from any cause occurred in 82 of 179 patients (45.8%) in the microaxial-flow-pump group and in 103 of 176 patients (58.5%) in the standard-care group (hazard ratio, 0.74; 95% confidence interval [CI], 0.55 to 0.99; P = 0.04). A composite safety end-point event occurred in 43 patients (24.0%) in the microaxial-flow-pump group and in 11 (6.2%) in the standard-care group (relative risk, 4.74; 95% CI, 2.36 to 9.55). Renal-replacement therapy was administered to 75 patients (41.9%) in the microaxial-flow-pump group and to 47 patients (26.7%) in the standard-care group (relative risk, 1.98; 95% CI, 1.27 to 3.09). The routine use of a microaxial flow pump with standard care in the treatment of patients with STEMI-related cardiogenic shock led to a lower risk of death from any cause at 180 days than standard care alone. The incidence of a composite of adverse events was higher with the use of the microaxial flow pump. (Funded by the Danish Heart Foundation and Abiomed; DanGer Shock ClinicalTrials.gov number, NCT01633502.).

Background— After acute myocardial infarction (AMI), diastolic function assessed by Doppler echocardiography provides important prognostic information that is incremental to systolic function. However, Doppler variables are affected by multiple factors and may change rapidly. In contrast, left atrial (LA) volume is less influenced by acute changes and reflects subacute or chronic diastolic function. This may be of importance when one assesses risk in patients with AMI. Methods and Results— Three hundred fourteen patients with AMI who had a transthoracic echocardiogram with assessment of left ventricular (LV) systolic and diastolic function and measurement of LA volume during admission were identified. The LA volume was corrected for body surface area, and the population was divided according to LA volume index of 32 mL/m ² (2 SDs above normal). LA volume index was >32 mL/m ² in 142 (45%). The primary study end point was all-cause mortality. During follow-up of 15 (range 0 to 33) months, 46 patients (15%) died. LA volume index was a powerful predictor of mortality and remained an independent predictor (hazard ratio 1.05 per 1-mL/m ² change, 95% CI 1.03 to 1.06, P <0.001) after adjustment for clinical factors, LV systolic function, and Doppler-derived parameters of diastolic function. Conclusions— Increased LA volume index is a powerful predictor of mortality after AMI and provides prognostic information incremental to clinical data and conventional measures of LV systolic and diastolic function.

Background: Percutaneous mechanical circulatory support devices are increasingly used in acute myocardial infarction complicated by cardiogenic shock (AMI-CS), despite limited evidence for their effectiveness. The aim of this study was to evaluate outcomes associated with use of the Impella device compared with intra-aortic balloon pump (IABP) and medical treatment in patients with AMI-CS. Methods: Data of patients with AMI-CS treated with the Impella device at European tertiary care hospitals were collected retrospectively. All patients underwent early revascularization and received optimal medical treatment. Using IABP-SHOCK II (Intraaortic Balloon Pump in Cardiogenic Shock II) trial inclusion and exclusion criteria, 372 patients were identified and included in this analysis. These patients were matched to 600 patients from the IABP-SHOCK II trial. The following baseline criteria were used as matching parameters: age, sex, mechanical ventilation, ejection fraction, prior cardiopulmonary resuscitation, and lactate. Primary end point was 30-day all-cause mortality. Results: In total, 237 patients treated with an Impella could be matched to 237 patients from the IABP-SHOCK II trial. Baseline parameters were similarly distributed after matching. There was no significant difference in 30-day all-cause mortality (48.5% versus 46.4%, P =0.64). Severe or life-threatening bleeding (8.5% versus 3.0%, P <0.01) and peripheral vascular complications (9.8% versus 3.8%, P =0.01) occurred significantly more often in the Impella group. Limiting the analysis to IABP-treated patients as a control group did not change the results. Conclusions: In this retrospective analysis of patients with AMI-CS, the use of an Impella device was not associated with lower 30-day mortality compared with matched patients from the IABP-SHOCK II trial treated with an IABP or medical therapy. To further evaluate this, a large randomized trial is warranted to determine the effect of the Impella device on outcome in patients with AMI-CS. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT03313687.