January 14, 2024
A groundbreaking study published in the Circulation Journal, the official journal of the Japanese Circulation Society, compares the outcomes of two mechanical circulatory support devices used in patients suffering from refractory cardiogenic shock (CS). The study titled “In-Hospital Mortality in Patients With Cardiogenic Shock Requiring Veno-Arterial Extracorporeal Membrane Oxygenation With Concomitant Use of Impella vs. Intra-Aortic Balloon Pump – A Retrospective Cohort Study Using a Japanese Claims-Based Database” explores the implications of using either an intra-aortic balloon pump (IABP) or the Impella device in conjunction with peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO).
Background
Cardiogenic shock remains a life-threatening complication characterized by inadequate end-organ perfusion due to primary cardiac dysfunction. The implementation of VA-ECMO has become a crucial intervention for patients in this dire state, as it provides vital hemodynamic support. However, VA-ECMO does not directly address the issue of afterload created by the ailing heart, which led to the concomitant use of devices like the Impella and IABP, both of which are intended to reduce the workload on the heart by improving myocardial recovery. The efficiency and cost-effectiveness of these devices in conjunction with VA-ECMO, however, had been a subject of much debate, with clinicians divided over their impacts on patient outcomes.
The Study
Manabu M. Nitta and colleagues, from the Yokohama City University Graduate School of Medicine, spearheaded the retrospective cohort review utilizing data from the Diagnosis Procedure Combination (DPC) database, which compiles information from approximately 1,200 acute care hospitals across Japan between April 2018 and March 2022. The study scrutinized records of 940 patients aged 18 years and above with CS necessitating the initiation of peripheral VA-ECMO within 48 hours of admission. They were then stratified according to the supplementary mechanical circulatory support device they received: the IABP (n=801) or Impella (n=139), termed ECMO-IABP, and ECPella, respectively.
Through propensity score matching, the study identified 126 pairs of patients with closely matched profiles, to allow for a more accurate comparison of outcomes between the two groups. The primary measure was in-hospital mortality, while secondary measurements included the duration of mechanical ventilator support, length of hospital stay, and medical costs incurred.
Key Findings
The key findings of the study revealed that there was no statistically significant difference in in-hospital mortality between the ECPella and ECMO-IABP groups, with rates of 50.8% and 50.0% respectively (P=1.000). However, the ECPella cohort was found to have spent a greater median length of time on mechanical ventilation compared to their counterparts (11.5 vs. 9.0 days; P=0.008). They also had a prolonged median hospital stay (32.5 vs. 23.0 days; P=0.017).
Furthermore, the study highlighted a stark difference in medical costs, with the ECPella group incurring higher expenses with a median range of 9.09 million Japanese yen, against 5.23 million yen for the ECMO-IABP group (P<0.001).
Implications and Future Directions
This nationwide study was crucial in providing insights into the comparative effectiveness of IABP and Impella when used in conjunction with VA-ECMO. While the results could not establish a difference in in-hospital mortality rates, the data underscores the need for further investigations to identify scenarios where the benefits of Impella could be maximized vis-à-vis patient care and economic considerations.
In light of the findings, there is a compelling need to enable clinicians in making informed decisions about employing mechanical circulatory support devices. This involves recognizing that while Impella might bestow certain hemodynamic advantages, its cost and extended use may not necessarily translate into improved mortality outcomes compared to IABP.
References
1. Nitta, M. M., Nakano, S. S., Kaneko, M. M., Fushimi, K. K., Hibi, K. K., & Shimizu, S. S. (2024). In-Hospital Mortality in Patients With Cardiogenic Shock Requiring Veno-Arterial Extracorporeal Membrane Oxygenation With Concomitant Use of Impella vs. Intra-Aortic Balloon Pump – A Retrospective Cohort Study Using a Japanese Claims-Based Database. Circulation Journal: Official Journal of the Japanese Circulation Society, CJ-23-0758.
Keywords
1. Cardiogenic shock treatment
2. VA-ECMO outcomes
3. Impella vs IABP
4. Mechanical circulatory support
5. ECMO cost-effectiveness
Conclusion
The revelations of this study necessitate a paradigm shift in the management of cardiogenic shock, placing the impetus on the medical community to judiciously assess the utility and costs of mechanical circulatory support devices. With no definitive evidence favoring the superior efficacy of Impella over IABP, the decision-making process should account for patient-specific clinical conditions and economic ramifications. This beckons an era of pragmatic and tailored therapeutic strategies in combatting cardiogenic shock with a focus on evidence-based outcomes and financial sustainability.