Risk Factors for Early Death in Patients Bridged to Transplant With Continuous-Flow Left Ventricular Assist Devices

Abstract

Background Recent evidence suggests patients bridged to heart transplant (BTT) have equivalent outcomes as those undergoing conventional heart transplantation (OHT). However, there are limited data on risk factors for early mortality in BTT patients. Methods We retrospectively reviewed the United Network for Organ Sharing (UNOS) database of all patients bridged to OHT with a HeartmateII (HMII) from 1/2005–12/2010. The primary outcome was all-cause 90-day mortality. Additional postoperative outcomes were cerebrovascular accident (CVA) and need for renal replacement therapy (RRT). Kaplan-Meier analysis assessed survival. Preoperative variables associated with 90-day mortality on univariate analysis (p<0.2) were included in a multivariable Cox proportional hazards regression. Results 1,312 patients were bridged to OHT with a HMII. During the study, 171 (13.0%%) patients died, and the unadjusted 90-day survival was 92.3%. Average age was 52±12 years, and the most common indication for OHT was idiopathic cardiomyopathy (N=665, 50.7%). Examining center volume for BTT recipients only, the highest annual average center volume in this cohort was 28 BTT procedures per year. Twenty-nine (2.2%) patients sustained a postoperative CVA and 106 (8.3%) required RRT. Cox regression revealed age, glomerular filtration rate, African-American race, human leukocyte antigen mismatch, serum bilirubin, need for mechanical ventilation, donor age, and prolonged ischemia time were associated with 90-day mortality. There was improved early mortality for patients transplanted at high volume centers (p=0.01). Conclusions This is the largest modern study to examine risk factors for early mortality in patients bridged to OHT, and the first to use UNOS data. With increasing use of HMII mechanical assistance to bridge patients to OHT, these findings will aid in identifying patients best suited to benefit from this therapy.

Institutional volume of heart transplantation with left ventricular assist device explantation influences graft survival

“…More recently, in a contemporary continuous flow LVAD population, patients implanted at centers performing < 15 LVADs per year had increased 90-day mortality (9). Arnaoutakis et al retrospectively evaluated risk factors for early death in a BTT continuous flow LVAD cohort undergoing OHT and found that a higher annual BTT LVAD-OHT procedure volume was associated with a lower risk of death (6). In our study, only centers in the lowest LVAD explant-OHT volume quartile had significantly decreased graft survival, suggesting an institutional LVAD explant-OHT learning curve.…”

Institutional Volume of Heart Transplantation with Left Ventricular Assist Device Explantation Influences Graft Survival

“…More recently, in a contemporary continuous flow LVAD population, patients implanted at centers performing < 15 LVADs per year had increased 90-day mortality (9). Arnaoutakis et al retrospectively evaluated risk factors for early death in a BTT continuous flow LVAD cohort undergoing OHT and found that a higher annual BTT LVAD-OHT procedure volume was associated with a lower risk of death (6). In our study, only centers in the lowest LVAD explant-OHT volume quartile had significantly decreased graft survival, suggesting an institutional LVAD explant-OHT learning curve.…”

“…Most significant advances have occurred during the first year after transplantation, likely related to improvement in surgical technique (4), and immunosuppressive therapy (1). Our understanding of the expertise needed to treat these complex patients has dramatically changed, as a clear association between transplant center volume and graft survival after transplant has been demonstrated, especially among patients with high perioperative risk (5)(6)(7). Landmark reports have identified a relationship between LVAD center implantation volume and survival for both pulsatile and continuous flow LVAD populations (8,9).…”

Comparison of early versus delayed timing of left ventricular assist device implantation as a bridge-to-transplantation: An analysis of the UNOS dataset

“…Our group has recently reported that pre-operative hypoalbuminemia is associated with poor prognosis following HTx and LVAD surgery (23-24). These concerning findings related to factors known to affect post-HTx outcomes (25-26) in addition an increased risk of LVAD-associated adverse events during the waiting period question the validity of an early implantation strategy in patients with INTERMACS level 4-6 awaiting HTx.…”