A 65-year-old woman with nonischemic cardiomyopathy on guideline-directed medical therapy presents with acute decompensated heart failure. While initially stable on standard therapy, she develops heart failure–associated cardiogenic shock (HF-CS) despite initiation of diuretics, with oliguria and lactate level 4 mmol/L (Society for Cardiovascular Angiography and Interventions [SCAI] stage C) prompting inotrope initiation. Uncertainty remains on the benefit of intra-aortic ballon pump (IABP) for survival or bridging to heart replacement therapy in such patients.

The Altshock-2 (Study on Early Intra-Aortic Balloon Pump Placement in Acute Decompensated Heart Failure Complicated by Cardiogenic Shock) built on a prior phase 2 trial of IABP followed by venoarterial extracorporeal membrane oxygenation in the setting of refractory cardiogenic shock (CS), which showed 87.5% 60-day survival and 61.9% transition to durable left ventricular assist device (LVAD).^1,2 In the Altshock-2, patients with HF-CS (SCAI stages B-D) were randomized to standard of care (SoC) or SoC plus early IABP. The primary endpoint, 60-day survival or LVAD/transplant, was not met, and the study was stopped early. Prior studies of IABP mostly assessed acute myocardial infarction–CS and did not demonstrate benefit, leading to IABP receiving a class IIIb recommendation per the European guidelines.³ The Altshock-2 results further argue against early IABP use in the setting of HF-CS.

No differences were seen between groups in inotrope use, vasodilators, respiratory support, Swan-Ganz use, or discharge medications.

Despite the pragmatic design, limitations remain, including exclusion of patients with CS due to valvular disease, arrhythmias, or myocarditis. The Altshock-2 population included 80% male patients from Italian centers, limiting generalizability, and recruited patients with SCAI stage B CS (27.7% overall), who are not typically treated with IABP and were not included in prior IABP trials. Importantly, IABP optimization was neither standardized nor recorded, as acknowledged by the investigators.

Regardless, the Altshock-2 results add skepticism to using the physiologically appealing, afterload-lowering IABP in HF-CS management. Clinicians may increasingly consider other temporary mechanical circulatory support tools other than IABP or carefully select the right patient at the right time. These results could influence future Organ Procurement and Transplantation Network (OPTN) status requirement updates.

References

1. Morici N, Sacco A, Frea S, et al. Early intra-aortic balloon support for heart failure-related cardiogenic shock: a randomized clinical trial. J Am Coll Cardiol. 2025;85(16):1587-1597. doi:10.1016/j.jacc.2025.03.003
2. Morici N, Oliva F, Ajello S, et al. Management of cardiogenic shock in acute decompensated chronic heart failure: the ALTSHOCK phase II clinical trial. Am Heart J. 2018;204:196-201. doi:10.1016/j.ahj.2018.07.009
3. Byrne RA, Rossello X, Coughlan JJ, et al. 2023 ESC guidelines for the management of acute coronary syndromes. Eur Heart J. 2023;44(38):3720-3826. doi:10.1093/eurheartj/ehad191