Left Ventricular Assist Device in Patients With Body Mass Index Greater Than 30 as Bridge to Weight Loss and Heart Transplant Candidacy

Sleeve gastrectomy facilitates weight loss and permits cardiac transplantation in patients with severe obesity and a left ventricular assist device (LVAD)

INTRODUCTION

Patients suffering from advanced heart failure may undergo left ventricular assist device (LVAD) placement as a bridge to cardiac transplantation. However, those with a BMI above 35 kg/m2 are generally not considered eligible for transplant due to their elevated cardiac risk. We review our experience with bariatric surgery in this high-risk population to assess its safety and efficacy in reducing BMI to permit cardiac transplantation.

METHODS

We retrospectively reviewed all patients on durable LVAD support who underwent sleeve gastrectomy (SG) at Mount Sinai Hospital between August 2018 and December 2022. Electronic medical records were reviewed to analyze patient demographics, surgical details, and outcomes regarding weight loss and heart transplantation.

RESULTS

We identified twelve LVAD patients who underwent SG. Three were performed laparoscopically and 9 via robotic approach. Four patients (33.3%) underwent an orthotopic heart transplant (OHTx). Half of these patients were female. For patients who underwent OHTx, mean age at LVAD placement was 41.0 (R30.6-52.2), at SG was 43.9 (R32.7-55.0) and at OHTx was 45.3 years (R33.3-56.8). Mean BMI increased from 38.8 at LVAD placement to 42.5 prior to SG. Mean time from SG to OHTx was 17.9 months (R6-7-27.5) during which BMI decreased to mean 32.8 at the time of OHTx. At most recent follow-up, mean BMI was 31.9. All patients were anticoagulated prior to surgery; one required return to the operating room on post-operative day 1 after SG for bleeding and one was re-admitted on post-operative day 7 for hematochezia treated conservatively.

CONCLUSION

SG is a safe and effective operation in patients with severe obesity and heart failure requiring an LVAD. 66.7% of our cohort achieved target BMI < 35 and 33.3% underwent heart transplantation. Longer term follow-up is needed to clarify full bridge-to-transplant rate and long-term survival outcomes.

Mechanical Circulatory Support as a Bridge-to-Transplant Candidacy: When Does It Work?

Durable mechanical circulatory support (dMCS) devices can be offered as a bridge-to-transplant (BTT) or as a bridge-to-candidacy (BTC) strategy for candidates with contraindications to transplant listing, including pulmonary hypertension (BTC-PH), morbid obesity (BTC-Obes), social issues (BTC-Soc), or chronic illness (BTC-Illness). An understanding of the trajectory of BTC patients could guide future triage of advanced heart failure patients who are not candidates for transplantation. We performed a retrospective review all patients who underwent dMCS implantation as either BTT (206 patients) or BTC (114 patients) at our center from January 1, 2010, to March 31, 2020. There was no significant difference in mortality between BTC patients and BTT patients. Compared with the BTT group, significantly more patients in the BTC-PH group were transplanted (81% vs. 63%; p < 0.05) and significantly fewer patients in the BTC-Obes group (44%; p < 0.05) and BTC-Soc group (39%; p < 0.05) were transplanted. Additionally, the readmission rate was higher for those in the BTC-Obes (6.2 vs. 2.1; p < 0.05) and BTC-Soc (3.9 vs. 2.1; p < 0.05) groups. Bridge-to-candidacy patients generally had poorer post-dMCS trajectories than BTT patients. Centers should not be dissuaded from pursuing a BTC strategy for qualified patients; however, careful consideration of potential adverse outcomes is necessary.

Isolated Left Ventricular Assist Device Implantation Produces Variable Changes to Patient Body Mass Index

BACKGROUND

Body Mass Index (BMI) is an important consideration for transplant-eligible Left Ventricular Assist Device (LVAD) recipients. LVAD therapy's impact on BMI is unclear. We evaluated BMI changes in patients who underwent LVAD implantation. The association between these patients' BMI and transplant was studied.

METHODS

This was a retrospective cohort study of patients who underwent LVAD implantation between January 1, 2012-December 31, 2018 at our institution. Patients were stratified by preoperative BMI (kg/m² ) into 4 groups: < 30, 30-34.9, 34.9-39.9, and ≥40. BMI data was collected at 12 and 6 months prior to implant, time of implantation, and 3- and 6- months post-implantation.

RESULTS

107 patients underwent LVAD implantation at our institution. Data was available for 80 patients. Baseline characteristics included mean age 56.0 years, 69% male, and mean implant BMI 29.9 ± 6.8 kg/m² . The mean BMI (kg/m² ) with each of the BMI (kg/m² ) groups <30, 30-34.9, 35-39.9, and ≥ 40 (n= 60, 25, 12, 10 respectively) was 25.1., 32.5, 36.8, and 43.8, respectively. There was no consistent pattern with weight change across differing implant BMIs. No patient with a BMI of <30 gained sufficient weight to impact transplant candidacy. 23% of patients with BMI of 30-34.9 kg/m² , 60% of patients with a BMI 35-39.9 kg/m² , and 87.5% of patients with a BMI of ≥40 had a 6-month BMI potentially affecting transplant.

CONCLUSIONS

Associated weight changes during LVAD support may significantly impact transplant candidacy. Higher BMI groups may benefit from multimodal and multidisciplinary targeted weight-loss interventions.

Left Ventricular Assist Device Support and Longitudinal Sleeve Gastrectomy Combined With Diet in Bridge to Heart Transplant

Combining left ventricular assist device (LVAD) implantation and longitudinal sleeve gastrectomy may enable patients with morbid obesity to lose enough weight for heart transplant eligibility. In a retrospective study, we evaluated long-term outcomes of patients with body mass indexes ≥35 who underwent LVAD implantation and longitudinal sleeve gastrectomy during the same hospitalization (from January 2013 through July 2018) and then adhered to a dietary protocol. We included 22 patients (mean age, 49.9 ± 12.5 yr; mean preoperative body mass index, 43.3 ± 6.2). Eighteen months after gastrectomy, all 22 patients were alive, and 16 (73%) achieved a body mass index of less than 35. Myocardial recovery in 2 patients enabled LVAD removal. As of October 2020, 10 patients (45.5%) had undergone heart transplantation, 5 (22.3%) were waitlisted, 5 (22.3%) still had a body mass index ≥35, and 2 (9%) had died. With LVAD support, longitudinal sleeve gastrectomy, and dietary protocols, most of our patients with morbid obesity and advanced heart failure lost enough weight for transplant eligibility. Support from physicians and dietitians can maximize positive results in these patients.

Clinical Outcomes, Trends in Weight, and Weight Loss Strategies in Patients With Obesity After Durable Ventricular Assist Device Implantation

PURPOSE OF REVIEW

To discuss clinical outcomes, changes in weight, and weight loss strategies of patients with obesity post left ventricular assist device (LVAD) implantation.

RECENT FINDINGS

Despite increased complications in patients with obesity after LVAD implantation, survival is comparable to patients without obesity. A minority of patients with obesity lose significant weight and become eligible for heart transplantation after LVAD implantation. In fact, a great majority of such patients gain weight post-implantation. Obesity by itself should not be considered prohibitive for LVAD therapy but, rather, should be incorporated into the overall risk assessment for LVAD implantation. Concerted strategies should be developed to promote sustainable weight loss in patients with obesity and LVAD to improve quality of life, eligibility, and outcomes after heart transplantation. Investigation of the long-term impact of weight loss on patients with obesity with LVAD is warranted.

Comparative analysis of regional outcomes and adverse events after continuous-flow left ventricular assist device implantation: An IMACS analysis

INTRODUCTION

Regional outcomes after implantation of continuous-flow left ventricular assist devices (LVADs) have not been described. We examined differences in patient selection, survival, and adverse events across 3 geographic regions of the world: the Americas, Asia-Pacific, and Europe.

METHODS

Using data from The International Society for Heart and Lung Transplantation Mechanically Assisted Circulatory Support registry, all adult patients implanted with a continuous-flow LVADs were included in this International Society for Heart and Lung Transplantation Mechanically Assisted Circulatory Support analysis (n = 15,560), of whom, 9,988 (64%) received axial-flow devices and 5,572 (36%) received centrifugal-flow devices.

RESULTS

There were significant interregional differences in the rate of implantation of patients aged >70 years (Americas: 14%, Asia-Pacific: 1%, Europe: 5%; p < 0.0001), morbidly obese (Americas: 5%, Asia-Pacific: 1%, Europe: 1%; p < 0.0001), male (Americas: 79%, Asia-Pacific: 77%, Europe: 85%; p < 0.0001), and implanted as destination therapy (Americas: 48%, Asia-Pacific: 4%, Europe: 22%; p < 0.0001). The rates of centrifugal pump usage varied by region (Americas: 30%, Asia-Pacific: 34%, Eu: 74%; p < 0.0001). Survival rates varied by region and the type of pump flow, with survival at 12 and 48 months (axial flow vs centrifugal flow) being 82% vs 82% and 52% vs 53 in Americas; 92% vs 86% and 83% vs 74% in Asia-Pacific; and 80% vs 75% and 69% vs 53% in Europe, respectively (regional survival p < 0.0001).

CONCLUSION

There are marked global differences in LVAD recipient characteristics, device utilization, and post-operative care. These heterogeneities along with differences in patient management and transplantation rates may impact long-term survival. Regional differences in adverse event incidence warrant further investigation.

Durable left ventricular assist device support as a bridge to heart transplant candidacy†

OBJECTIVES

Left ventricular assist devices are funded in the UK exclusively as a bridge to transplant (BTT). However, patients who potentially could receive a transplant may develop reversible contraindications to transplant. Bridge to candidacy (BTC) has sometimes been controversial, given the uncertain clinical efficacy of BTC and the risk that reimbursement could be denied. We analysed the UK ventricular assist device database to understand how common BTC was and to assess patient survival rates and incidences of transplants.

METHODS

We identified BTC implants in patients with pulmonary hypertension, chronic kidney disease and obesity using the UK guidelines for heart transplants.

RESULTS

A total of 306 of 540 patients had complete data and 157 were identified as BTC (51%). Overall, there was no difference in survival rates between patients designated as BTC and those designated at BTT (71.9 vs 72.9% at 1 year, respectively; P = 0.82). However, the survival rate was lower at all time points in those with an estimated glomerular filtration rate (eGFR) <40 and in patients with a body mass index (BMI) >32 up to 1-year postimplant. There were no significant differences in the incidence of transplant between patients who were BTC and BTT or for any subgroup up to 5 years. However, we noted a diverging trend towards a lower cumulative incidence of transplant for patients with a BMI >32.

CONCLUSIONS

BTC is common in the UK and appears clinically effective, given that the survival rates and the incidence of transplants were comparable with those for BTT. Patients with a high BMI have a worse survival rate through to 1 year and a trend for a lower incidence of a transplant. Patients with a low eGFR also have a worse survival rate, but a similar proportion received transplants.

Impact of Obesity on Ventricular Assist Device Outcomes

BACKGROUND

Obesity remains a relative contraindication for heart transplantation, and hence, obese patients with advanced heart failure receive ventricular assist devices (VADs) either as a destination or "bridge to weight loss" strategy. However, impact of obesity on clinical outcomes after VAD implantation is largely unknown. We sought to determine the clinical outcomes of obese patients with body mass index (BMI) ≥ 35 kg/m²) following contemporary VAD implantation.

METHODS

The Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) registry was queried for patients who underwent VAD implantation. Patients were categorized into BMI groups based on World Health Organization classification.

RESULTS

Of 17,095 patients, 2620 (15%) had a BMI ≥ 35 kg/m². Obese patients were likely to be young, non-white, females with dilated cardiomyopathy and undergo device implantation as destination. Survival was similar amongst BMI groups (P = .058). Obese patients had significantly higher risk for infection (hazard ratio [HR]: 1.215; P = .001), device malfunction or thrombosis (HR: 1.323; P ≤ .001), cardiac arrhythmia (HR: 1.188; P = .001) and hospital readmissions (HR: 1.073; P = .022), but lower risk of bleeding (HR: 0.906; P = .018). Significant weight loss (≥10%) during VAD support was achieved only by a small proportion (18.6%) of patients with BMI ≥ 35 kg/m². Significant weight loss rates observed in obese patients with VAD implantation as destination and bridge to transplant strategy were comparable. Obese patients with significant weight loss were more likely to undergo cardiac transplantation. Weight loss worsened bleeding risk without altering risk for infection, cardiac arrhythmia, and device complications.

CONCLUSIONS

Obesity alone should not be considered a contraindication for VAD therapy in contemporary era. Given durability of heart transplantation, strategies should be developed to promote weight loss, which occurs infrequently in obese patients. Impact of weight loss on clinical outcome of obese patients warrants further investigation.

Adult Congenital Heart Disease: Current Early Expectations After Cardiac Transplantation

BACKGROUND

Early mortality has plagued the otherwise good outcomes of heart transplantation in patients with adult congenital heart disease (ACHD), but perioperative care is improving. This study sought to identify risk factors for 1-year mortality currently and examine the results of patients without those risk factors compared with patients who did not have ACHD (nACHD).

METHODS

The United Network of Organ Sharing database was searched for all adult (>17 years of age) heart transplant recipients from 2000 to 2018. They were divided into an early era and a late era. A multivariate analysis identified risk factors for 1-year mortality in the late era. Patients without these risk factors were compared with the nACHD group by Kaplan-Meier analysis.

RESULTS

A total of 495 patients with ACHD were identified from 2000 to 2008, and 666 were identified from 2009 to 2018. The recent era had better 1-year survival (P <.001) and overall survival (P = .003) than did the era from 2000 to 2008. Patients with ACHD were different from the nACHD population in age (37 years vs 57 years), body mass index greater than 25 kg/m² (45% vs 66%), incidence of renal dysfunction (23% vs 28%) and liver dysfunction (29% vs 23%), sensitization (38% vs 29%), and ischemic times (3.5 hours vs 3.1 hours). Multivariate analysis identified body mass index greater than 25 kg/m² (hazard ratio [HR], 1.79), renal dysfunction (HR, 1.85), liver dysfunction (HR, 1.69), and longer ischemic time (HR, 1.46) as risk factors for early mortality. Patients with only 1 of the first 3 categorical risk factors had 1-year survival comparable to that reported in patients with nACHD.

CONCLUSIONS

Patients with ACHD had better early and long-term outcomes in the recent era. When only 1 of 3 pretransplant risk factors for early mortality was present, patients had survival equal to that of nACHD patients and perhaps better long-term survival.

Obesity in patients with end-stage heart failure

Obesity poses an increasing problem in patients with end-stage heart failure (HF). The most commonly used indicator of obesity is body mass index. The value of this parameter is widely taken into consideration when selecting the best way of treatment for patients with advanced HF. The aim of this paper is to outline the recent knowledge about obesity in the abovementioned group of patients.

Current status of the implantable LVAD

With the ongoing shortage of available organs for heart transplantation, mechanical circulatory support devices have been increasingly utilized for managing acute and chronic heart failure that is refractory to medical therapy. In particular, the introduction of the left ventricular assist devices (LVAD) has revolutionized the field. In this review, we will discuss a brief history of the LVAD, available devices, current indications, patient selection, complications, and outcomes. In addition, we will discuss recent outcomes and advancements in the field of noncardiac surgery in the LVAD patient. Finally, we will discuss several topics for surgical consideration during LVAD implantation.