Results

Comparison between trial and postapproval group patients

Baseline characteristics between the trial and postapproval patients were comparable, except for age, preoperative international normalized ratio (INR), indication for implantation (BTT vs DT), and use of temporary assist device other than intra-aortic balloon pump (IABP) prior to the HM3 implantation (Table 1). The postapproval group had younger patients (49.60 ± 13.92 vs 55.40 ± 11.54 years p=0.01 ), a higher pre-operative mean INR (1.13 ± 0.18 vs 1.08 ± 0.16p=0.04 ), more BTT patients (25% vs 13.4% p=0.05 ) and more patients supported with Impella 5.0, Tandem, or extracorporeal membrane oxygenation (ECMO) (7.6% vs 0% p=0.01 ) than the trial group. Also, the postapproval group had more patients in INTERMACS profile 1 (18.5% vs 7.3% p=0.04 ) than the trial group.

Characteristics of postapproval group patients

Baseline characteristics for the 92 patients in the postapproval group are provided in Table 1. The mean age at the time of an implant was 49.60 ± 13.92 years. The majority were African American (64.1%), male (81.5%), and implanted as DT (75%). Of the 92 patients, 68 (73.9%) had INTERMACS profile 1-2. Before receiving an LVAD, seven (7.6%) patients were upgraded from IABP to a higher support temporary mechanical circulatory assist device (Tandem, Impella 5.0, or ECMO) for ongoing cardiogenic shock. As shown in Table 2, the median length of hospital stay after the surgery was 22 (IQR 17-28) days. The average pump speed at the time of discharge from the hospital was 5,300 ± 260 rpm with an average pump flow of 4.29 ± 0.46 L/min.

6-month survival

In the postapproval group, 30-day survival was 97.8% and 6-month survival was 93.3% (Table 2 and Figure 2). Four patients underwent heart transplantation during the first 6 months of follow-up. Six deaths occurred during the first 6 months of HM3 support. Differentiating 6-month survival based on the indication of implantation, survival in the DT group was 88.9% vs 100% (0.12) in the BTT group. At 3-month follow-up after LVAD implant, 59 (71.1%) patients were NYHA class 2 (Table 2).