The Effect of Continuous-Flow Left Ventricular Assist Device Duration on Postoperative Outcomes

Early outcomes in heart transplantation using donation after circulatory death donors in patients bridged with durable left ventricular assist devices

OBJECTIVE

Donation after circulatory death heart transplantation potentially increases donor allografts, especially for patients with lower listing status. We assessed the outcomes of donation after circulatory death heart transplantation in patients bridged with durable left ventricular assist devices.

METHODS

The United Network for Organ Sharing database was queried for adult heart transplants using donation after circulatory death donors from 2019 to 2022. Patients were stratified between those with durable left ventricular assist devices and those with intra-aortic balloon pump, inotropic, or no bridging support (control group). Primary outcome was 1-year mortality. Secondary end points were hospital length of stay, stroke, pacemaker implantation, dialysis, and acute rejection before discharge.

RESULTS

A total of 160 left ventricular assist device recipients and 311 control recipients met study inclusion criteria. Recipients bridged with left ventricular assist devices were younger (55 vs 58 years, P < .001) with lower body mass index (28.3 vs 30.3, P < .001), longer waitlist times (112 vs 34 days, P < .001), longer out of body times (5.7 vs 4.6 hours, P < .001), and less frequent normothermic regional perfusion (31% vs 40%, P = .049). Patients with left ventricular assist devices commonly underwent transplantation at United Network for Organ Sharing status 3 and 4 (92%), whereas control patients underwent transplantation at status 2 (27%), status 3 (10%), status 4 (30%), or status 6 (30%). Kaplan-Meier analysis showed no difference in 1-year mortality between groups (P = .34). However, acute rejection was higher in the unadjusted left ventricular assist device cohort (26% vs 13%, P < .001). On multivariable logistic regression, left ventricular assist device was an independent predictor of acute rejection (odds ratio, 2.21, 95% CI, 1.32-3.69, P = .002).

CONCLUSIONS

Durable left ventricular assist devices may be associated with a higher risk of developing an early inflammatory response in donation after circulatory death heart transplantation; however, 1-year survival was similar between groups.

Cardiac allograft rejection in the current era of continuous flow left ventricular assist devices

OBJECTIVE

Left ventricular assist device (LVAD) implantation has been shown to increase allosensitization before orthotopic heart transplantation, but the influence of LVAD support on posttransplant rejection is controversial. This study examines the postoperative incidence of acute cellular rejection (ACR) in patients bridged with continuous flow LVAD (CF-LVAD) relative to primary transplant (Primary Tx).

METHODS

All patients who underwent orthotopic heart transplantation at our institution between July 2006 and March 2019 were retrospectively reviewed (n = 395). Patients were classified into Primary Tx (n = 145) and CF-LVAD (n = 207) groups. Propensity score matching on 13 covariates implemented a 0.1 caliper logistic model with nearest neighbor 1:1 matching. Development of moderate to severe (ie, 2R/3R) rejection was evaluated using a competing risks model. Potential predictors of 2R/3R ACR were evaluated using Fine-Gray regression on the marginal subdistribution hazard.

RESULTS

Propensity score matching yielded 122 patients in each group (n = 244). At 12 and 24 months, the cumulative incidence of 2R/3R ACR was 17% and 23% for the CF-LVAD group and 26% and 31%, respectively, for the Primary Tx group (P = .170). CF-LVAD was not predictive of 2R/3R rejection on multivariable Fine-Gray regression (subdistribution hazard ratio, 0.73; 95% confidence interval, 0.40-1.33; P = .301). There was no difference in the 5-year incidence of antibody mediated rejection (10% [n = 12] vs 9% [n = 11]; P = .827).

CONCLUSIONS

After adjusting for covariates, CF-LVAD was not associated with an increased risk of moderate to severe ACR during the 24 months after cardiac transplantation. Further investigation is warranted with larger cohorts, but CF-LVAD may have minimal influence on posttransplant ACR.

The Impact of Left Ventricular Assist Device Infections on Postcardiac Transplant Outcomes: A Systematic Review and Meta-Analysis

Left ventricular assist devices (LVADs) are associated with numerous short- and long-term complications, including infection. The impact LVAD infections have on clinical outcomes after transplantation is not well established. We sought to determine whether the presence of infection while on LVAD support negatively influences outcomes after cardiac transplantation. We searched electronic databases and bibliographies for full text studies that identified LVAD infections during support and also reported on posttransplant outcomes. A meta-analysis of posttransplant survival was conducted using a random effects model. Of 2,373 records, 13 bridge to transplant (BTT) cohort studies were selected (n = 6,631, 82% male, mean age 50.7 ± 2.7 years). A total of 6,067 records (91.5%) received transplant. There were 3,718 (56.1%) continuous-flow LVADs (CF-LVADs), 1,752 (26.4%) pulsatile LVADs, and 1,161 (17.5%) unknown type records. A total of 2,586 records (39.0%) developed LVAD infections. Patients with LVAD infections were younger (50.5 ± 1.5 vs. 51.3 ± 1.5, p = 0.02), had higher body mass indeices (BMIs) (28.4 ± 0.7 vs. 26.8 ± 0.4, p < 0.01), and longer LVAD support times (347.0 ± 157.6 days vs. 180.2 ± 106.0 days, p < 0.01). Meta-analysis demonstrated increased posttransplant mortality in those patients who had an LVAD infection (hazard ratio [HR] 1.30, 95% CI: 1.16-1.46, p < 0.001). Subgroup meta-analyses by continuous-flow and pulsatile device type demonstrated significant increased risk of death for both types of devices (HR 1.47, 95% CI: 1.22-1.76, p < 0.001 and 1.71, 95% CI: 1.19-2.45, p = 0.004, respectively). Patients who develop LVAD infections are younger, have higher BMIs and longer LVAD support times. Our data suggests that LVAD-related infections result in a 30% increase in postcardiac transplantation mortality. Strategies to prevent LVAD infections should be implemented to improve posttransplant outcomes in this high-risk population.

Transplant Outcomes in Destination Therapy Left Ventricular Assist Device Patients

Left ventricular assist devices (LVAD) can be implanted as either a bridge to transplantation (BTT) or destination therapy (DT). This definition is fluid, as some DT patients undergo transplantation. This study compared posttransplant outcomes between BTT and DT LVAD patients. We performed a retrospective analysis of LVAD patients who underwent cardiac transplantation from 2010 to 2016. Outcomes including mortality, rejection, infection, and overall readmission were assessed with univariable Cox analyses. This cohort included 92 LVAD patients underwent transplantation: 57 BTT, mean age 52 years, and 79% male. The DT group had a longer LVAD support time (median support 406 versus 161 days, p < 0.001) with no significant difference in 1-year survival (BTT 86% and DT 92%, p = 0.52) or survival time (HR 0.89, 95% confidence interval [CI] 0.33-2.41, p = 0.82). Rates of nonfatal adverse events were also similar between BTT and DT patients. In our cohort, DT patients had similar long-term survival and rates of adverse events as compared with BTT, despite a longer time to transplant. This study suggests that transplant outcomes are acceptable for patients initially labeled DT and that a longer duration of LVAD support may not adversely affect posttransplant outcomes.