A tale of 2 left ventricular assist devices: is it the age for personalized mechanical circulatory support?

In the current era, continuous-flow left ventricular assist devices (LVADs)—mainly the HeartWare HVAD (HW) and HeartMate 3 (HM3)—are the preferred mechanical circulatory support apparatus for patients with advanced heart failure either as a bridge to a heart transplant or as a destination therapy, and their use is on the rise [1, 2]. Nevertheless, comparative data regarding clinical outcomes and device-related complications between these 2 devices are limited, possibly preventing further prognostic improvement in the management of patients with advanced heart failure.

In this issue of the Journal, Evgenij Potapov and colleagues [3] have reported the results of a retrospective multicentre analysis of propensity score-matched with HW or HM3 LVAD implants based on data from 2016 to 2020 from the European Registry for Patients with Mechanical Circulatory Support (EUROMACS) registry. The propensity score matching, calculated by logistic regression, included patient demographics, Interagency Registry for Mechanically Assisted Circulatory Support profiles and systemic organ dysfunction. Competing risk analyses were used to evaluate the incidence of adverse events relating to all-cause death, weaning or a heart transplant as competing outcomes. After matching, each study group included 361 patients with a median follow-up of 396 days. The investigators found similar survival between patients implanted with HM3 compared with HW LVADs, despite a higher risk of device malfunction and neurological dysfunction in patients implanted with the HW and longer operating times for patients implanted with the HM3.

The authors should be congratulated for addressing the knowledge gap in the contemporary management of patients with advanced heart failure and for their meticulous statistical design. A prospective randomized controlled trial comparing HM3 with HW LVADs has not yet been performed, and even if one is currently being designed, its results would be presented only several years ahead with newer devices already available. Therefore, in a reality where the medical staff caring for patients with LVADs rely on evidence from retrospective studies to develop clinical management strategies, a propensity score-matching analysis of a large-scale cohort such as the EUROMACS contributes significantly to the current literature.

A major finding is that the overall survival of patients implanted with HM3 or HW LVADs was comparable, allegedly obviating the need for all centres to implant both types of devices. However, due to the unique advantages and disadvantages offered by each device, we believe clinicians should be familiar with the different characteristics of each LVAD and personalize the most appropriate device to the individual patient during the pre-implant decision process. The HM3 LVAD has repeatedly shown decreased rates of neurological injury post-implant, including but not limited to intracranial bleeding [3–6], and a lower risk of device malfunction, specifically pump thrombosis [3, 4, 6, 7]. Therefore, taking these advantages altogether, the HM3 LVAD should be preferred in patients designated for LVAD support as destination therapy or in patients with a pre-implant history of adverse neurological events. Alternately, the HW LVAD, characterized by a smaller design, may be better adjusted for smaller patients (such as women or even children) who are designated for an LVAD as a bridge to a heart transplant.

Although this is indeed the largest published propensity score-matched retrospective comparison between HM3 and HW LVADs, this study is limited by the variability in the standard of care practices in the participating EUROMACS centres (specifically antithrombotic and antihypertensive regimen protocols) and by the absence of data regarding baseline haemodynamic catheterization parameters and right ventricular assessment. A focused study integrating these parameters would further expand our skills in the art of adjusting ‘the right device for the right patient’.

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