Patients and Methods

Study design

This single-center, retrospective, observational study included patients who underwent implantation of the HM3 LVAD between October 2017 and March 2020. Data were collected prospectively and entered into an institutional patient registry database. This study was approved by the Ochsner Institutional Review Board (IRB), and all patients consented or waived informed consent as per the IRB policy. To standardize our approach and better compare the findings with HM3 trial results and future studies, we used the standardized Mechanical Circulatory Support-Academic Research Consortium (MCS-ARC) Adverse Events for Outcomes and Adverse Events.11

Study population

Inclusion criteria for this study were 1) primary implantation with the HM3 LVAD during the study period and 2) availability of 6-month follow-up after LVAD implantation.
A total of 189 patients were implanted with the HM3 at our institution from October 2017 to March 2020. Eighty-two patients were included in the trial group (MOMENTUM 3 and CAP trials) and formed the comparator group, while the remaining 107 patients were implanted after FDA approval of the device (postapproval group). From these 107 patients, 102 patients met the primary HM3 implant criteria; the 5 excluded patients were implanted with the HM3 as a replacement device for previously placed durable mechanical devices. Of the 102 patients, 92 patients were selected for the final analysis because they had completed 6 months of follow-up (Figure 1).

Data collection

Patient baseline information included demographic details, comorbidities, preoperative echocardiographic findings, preoperative right heart catheterization pressures, INTERMACS profile, New York Heart Association (NYHA) functional classification, indication for mechanical support, and preoperative laboratory values. Adverse events within the first 6 months of the implant were also collected.

Endpoints

The primary endpoint was survival at 6 months. Secondary endpoints included freedom from pump thrombosis (requiring reoperation or pump exchange) and other adverse events such as re-exploration for bleeding, stroke, acute limb ischemia, gastrointestinal bleeding, driveline infection, renal dysfunction requiring renal replacement therapy, and right ventricular failure (RVF).

Statistical analysis

Categorical data are reported as frequencies and percentages and were compared using the chi-square test. Continuous data are reported either as mean ± standard deviation (SD) or median with interquartile range (IQR) unless specified otherwise. Continuous data were compared using the two-sided Wilcoxon-Mann-Whitney test. The log-rank test was used for time-to-event analysis, with patient survival data presented as a Kaplan-Meier survival curve up to 6 months from an implant date. Patients were censored when they were transplanted. Statistical significance was defined as p ≤0.05. The data were analyzed using SAS/STAT software version 14.2 (SAS Institute Inc).