Outcomes in patients with smaller body surface area after HeartMate 3 left ventricular assist device implantation

Less Invasive Left Ventricular Assist Device Implantation Is Safe and Feasible in Patients With Smaller Body Surface Area

OBJECTIVE

Smaller body surface area (BSA) frequently precludes patients from left ventricular assist device (LVAD) therapy. We sought to investigate the clinical outcomes in patients with small BSA undergoing less invasive LVAD implantation.

METHODS

We conducted a retrospective review of 216 patients implanted with HeartMate 3 LVAD (Abbott, Chicago, IL) via less invasive surgery at our institution. Patients were dichotomized based on their preimplant BSA for comparison between small BSA (≤1.8 m2) and normal/large BSA (>1.8 m2). We analyzed patient perioperative characteristics and outcomes.

RESULTS

In our study, small BSA was found in 32 patients (14.8%), while 184 patients (85.2%) had normal/large BSA. Women were more prevalent in the small BSA group (50.0% vs 13.0%, P < 0.001). Preoperative and intraoperative data showed comparable results. Major complications and hospital length of stay did not differ by BSA group. Patients with smaller BSA had significantly decreased pump parameters at discharge, including LVAD flow (4.11 ± 0.49 vs 4.60 ± 0.54 L/min, P < 0.001) and pump speed (5,200 vs 5,400 rpm, P < 0.001). Survival to discharge and within 6 months after implantation were similar between the groups.

CONCLUSIONS

Our study results suggest that less invasive HeartMate 3 implantation can be safely performed and demonstrates equivalent outcomes in patients with smaller body habitus. Randomized trials are required to confirm our data.

Sex-Associated Differences in the Clinical Outcomes of Left Ventricular Assist Device Recipients: Insights From Interagency Registry for Mechanically Assisted Circulatory Support

BACKGROUND

Sex-associated differences in clinical outcomes among left ventricular assist device recipients in the United States have been recognized. However, an investigation of the social and clinical determinants of sex-associated differences is lacking.

METHODS

Left ventricular assist device receiving patients enrolled in Interagency Registry for Mechanically Assisted Circulatory Support between 2005 and 2017 were included. The primary outcome was all-cause mortality. Secondary outcomes included heart transplantation and postimplantation adverse event rates. The cohort was stratified by the social subgroup of race and ethnicity (non-Hispanic White, non-Hispanic Black, non-Hispanic Asian, and Hispanic), and clinical subgroups of device strategy (destination therapy, bridge to transplant, and bridge to candidacy), and implantation center volume (low [≤20 implants/y], medium [21-30 implants/y], and high [>30 implants/y]). A multivariable-adjusted Cox proportional hazard model was used to assess the risk of death and heart transplantation with prespecified interaction testing. Poisson regression was used to estimate adverse events by sex across the various subgroups.

RESULTS

Among 18 525 patients, there were 3968 (21.4%) females. Compared with their male counterparts, Hispanic (adjusted hazard ratio [HRadj], 1.75 [1.23-2.47]) females had the highest risk of death followed by non-Hispanic White females (HRadj, 1.15 [1.07-1.25]; Pinteraction=0.02). Hispanic (HRadj, 0.60 [0.40-0.89]) females had the lowest cumulative incidence of heart transplantation followed by non-Hispanic Black females (HRadj, 0.76 [0.67-0.86]), and non-Hispanic White females (HRadj, 0.88 [0.80-0.96]) compared with their male counterparts (Pinteraction<0.001). Compared with their male counterparts, females on the bridge to candidacy strategy (HRadj, 1.32 [1.18-1.48]) had the highest risk of death (Pinteraction=0.01). The risk of death (Pinteraction=0.44) and cumulative incidence of heart transplantation (Pinteraction=0.40) did not vary by sex in the center volume subgroup. A higher incidence rate of adverse events after left ventricular assist device implantation was also seen in females compared with the males, overall, and across all subgroups.

CONCLUSIONS

Among left ventricular assist device recipients, the risk of death, the cumulative incidence of heart transplantation, and adverse events differ by sex across the social and clinical subgroups.

The impact of left ventricular size on outcomes after centrifugal-flow left ventricular assist device implantation

OBJECTIVES

The influence of preoperative left ventricular size in outcomes following centrifugal-flow left ventricular assist device (LVAD) implantation has not been well characterized.

METHODS

A cohort of 313 patients who received a centrifugal-flow LVAD at a single institution was analysed. Using a maximally selected log-rank statistic, we investigated whether a left ventricular end-diastolic dimension (LVEDD) cut-off point was associated with worse outcomes. The cohort was then divided in 2 groups based on the LVEDD cut-off point.

RESULTS

An LVEDD cut-off point of 59 mm was found to predict worse survival. Smaller LVEDD patients (≤59 mm, N = 52) were older and more likely to have a history of coronary artery disease compared those with a larger LVEDD (>59 mm, N = 261). Smaller LVEDD patients had lower survival compared to larger LVEDD patients (71% vs 85% at 1 year and 58% vs 80% at 2 years, P = 0.003). The need for temporary right ventricular mechanical support was significantly higher in the smaller LVEDD cohort (11.5% vs 1.9%, P = 0.002). Pump flows at time of discharge were lower in the smaller LVEDD group (3.8 vs 4.2 l/min, P = 0.005), who also had a higher incidence of late right ventricular failure (23% vs 12%, P = 0.02), higher rates of gastrointestinal bleeding (0.416 vs 0.256 events per patient-year, P = 0.025) and higher readmissions secondary to low flow alarms (0.429 vs 0.240 events per patient-year, P = 0.007). Multivariable analysis demonstrated that smaller LVEDD, older age, high BUN and high bilirubin levels were independent predictors of worse survival.

CONCLUSIONS

In patients receiving a centrifugal-flow LVAD, smaller preoperative LVEDD (≤59 mm) was associated with lower survival and higher incidence of adverse outcomes.