Escalation From Intra-Aortic Balloon Pump in Cardiogenic Shock Patients: A Multistate Analysis of the Altshock-2 Registry

Cardiogenic shock is a deadly disorder and temporary mechanical circulatory support devices (tMCS) have been introduced to improve survival. However, criteria and strategies for timely placement and escalation are lacking. A major limitation of previous research is the focus on a single intervention or device; in clinical practice, these patients are transitioned through multiple configurations of tMCS. Accordingly, we have applied the generalized framework of a multistate model to enhance our understanding of the disease process. A multistate survival analysis was conducted on the Altshock-2 registry to describe the proportions, over time, of patients alive without tMCS (starting state), and being treated with tMCS until heart replacement therapy (disease transitions) or, ultimately, death (absorbing state). Among 544 included patients 199 (36.6%) did not receive any tMCS, 252 (46.3%) received a single device (81% intra-aortic balloon pump [IABP]), and 93 (17.1%) underwent escalation. Considering only patients with IABP (281 patients), 77 (27.4%) underwent escalation whereas 204 received IABP as the only tMCS, with in-hospital death of 59.1% and 40.5%, respectively (p <0.01). IABP escalation was associated with increased mortality compared with IABP alone only in the acute coronary syndrome (ACS) group (RR 1.74, 95% CI 1.29 to 2.35), whereas no difference was observed in the heart failure (HF) group (RR 0.66, 95% CI 0.28 to 1.58), also after adjustment for SCAI stage at 24 hours from admission. In conclusion, the need to escalate from IABP to other tMCS devices is associated with increased mortality in the setting of ACS-CS. Timely implantation of the right tMCS is a key factor in CS treatment.