Microaxial flow pump improves survival among patients with STEMI-related cardiogenic shock

medwireNews: Routine use of a microaxial flow pump in addition to standard care reduces the risk for death from any cause among patients with ST-segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock, show data from the international DanGer Shock trial. However, patients given temporary mechanical circulatory support with the Impella CP (Abiomed Inc, Massachusetts, USA) microaxial flow pump had a higher incidence of adverse events such as moderate or severe bleeding and renal replacement therapy, report Jacob Møller and co-authors in The New England Journal of Medicine. In an accompanying editorial, Sunil Rao (New York University Grossman School of Medicine, USA) writes: “[T]he high incidence of complications underscores the importance of strategies such as ultrasound-guided vascular access to reduce bleeding at the femoral access site and the use of antegrade catheters in the ipsilateral limb to maintain distal perfusion when the microaxial flow pump device is placed.” The study, which was simultaneously presented at the American College of Cardiology Scientific Sessions 2024 in Atlanta, Georgia, USA, included 355 patients (median age 67 years, 79% men) with STEMI and cardiogenic shock, defined as hypotension (systolic blood pressure below 100 mmHg or an ongoing need for vasopressor support), end-organ hypoperfusion with an arterial lactate level of 2.5 mmol/L or greater, and a left ventricular ejection fraction below 45%. Patients who had a Glasgow Coma Scale score below 8 points after resuscitation from out-of-hospital cardiac arrest and those with overt right ventricular failure were excluded. Møller et al report that, during 180 days of follow-up, the all-cause mortality rate was 45.8% among the 179 patients randomly assigned to receive a microaxial flow pump plus standard care. By comparison, the rate was 58.5% among the 176 patients who received standard care alone. The difference between the two groups was statistically significant and corresponded to a 26% lower risk for death in favor of microaxial flow pump use. Conversely, the risk for experiencing complications was a significant 4.74 times higher with the microaxial flow pump relative to standard care. Specifically, 24.0% of individuals who received the intervention experienced at least one component of a composite safety outcome that included severe bleeding, limb ischemia, hemolysis, device failure, or worsening aortic regurgitation. The rate was 6.2% among those who only received standard care. Among individual adverse events, the relative risk (RR) for moderate or severe bleeding was a significant 2.06 in the microaxial flow pump group versus the standard care group (21.8 vs 11.9%). The RRs for limb ischemia, sepsis with a positive blood culture, and renal replacement therapy were 5.15 (5.6 vs 1.1%), 2.79 (11.7 vs 4.5%), and 1.98 (41.9 vs 26.7%), respectively. Despite the higher complication rate, the researchers say that “it is reassuring that these severe complications did not overshadow the benefit of treatment with a microaxial flow pump.” They add: “It remains a priority to address the prevention of serious adverse events that occur as a result of treatment with a microaxial flow pump.” Rao describes the findings as “striking” and says that they “mark the first treatment strategy to show a benefit in patients with [STEMI-related cardiogenic shock] since the SHOCK trial, published in 1999, established percutaneous coronary intervention as the cornerstone of treatment.” He adds, however, that unanswered questions remain, including the timing of microaxial flow pump placement, the incorporation of shock protocols as a standardized approach, and the combined use of the microaxial flow pump with other mechanical circulatory support. medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2024 Springer Healthcare Ltd, part of the Springer Nature Group N Engl J Med 2024; doi:10.1056/NEJMoa2312572 N Engl J Med 2024; doi:10.1056/NEJMoa2402310 ACC 2024; Atlanta, Georgia, USA: 6–8 April

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Microaxial flow pump improves survival among patients with STEMI-related cardiogenic shock

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