Weight Gain After Heart Transplantation in Adults: Systematic Review and Meta-Analysis

Cardio-Renal-Metabolic Outcomes Associated With the Use of GLP-1 Receptor Agonists After Heart Transplantation

BACKGROUND

The use of glucagon-like-peptide 1 receptor agonists (GLP1-RA) has dramatically increased over the past 5 years for diabetes mellitus type 2 (T2DM) and obesity. These comorbidities are prevalent in adult heart transplant (HT) recipients. However, there are limited data evaluating the efficacy of this drug class in this population. The aim of the current study was to describe cardiometabolic changes in HT recipients prescribed GLP1-RA at a large-volume transplant center.

METHODS

We retrospectively reviewed all adult HT recipients who received GLP1-RA after HT for a minimum of 1-month. Cardiometabolic parameters including body mass index (BMI), lipid panel, hemoglobin A1C, estimated glomerular filtration rate (eGFR), and NT-proBNP were compared prior to initiation of the drug and at most recent follow-up. We also evaluated for significant dose adjustments to immunosuppression after drug initiation and adverse effects leading to drug discontinuation.

RESULTS

Seventy-four patients were included (28% female, 53% White, 20% Hispanic) and followed for a median of 383 days [IQR 209, 613] on a GLP1-RA. The majority of patients (n = 56, 76%) were prescribed semaglutide. The most common indication for prescription was T2DM alone (n = 33, 45%), followed by combined T2DM and obesity (n = 26, 35%). At most recent follow-up, mean BMI decreased from 33.3 to 31.5 kg/m2 (p < 0.0001), HbA1C from 7.3% to 6.7% (p = 0.005), LDL from 78.6 to 70.3 mg/dL (p = 0.018) and basal insulin daily dose from 32.6 to 24.8 units (p = 0.0002).

CONCLUSION

HT recipients prescribed GLP1-RA therapy showed improved glycemic control, weight loss, and cholesterol levels during the study follow-up period. GLP1-RA were well tolerated and were rarely associated with changes in immunosuppression dosing.

Association of diet quality and weight increase in adult heart transplant recipients

BACKGROUND

Understanding the quality of the diet of heart transplant recipients (HTRs) is essential to developing effective dietary interventions for weight control, but relevant evidence is scarce. We investigated diet quality and its association with post-transplant increase in weight adjusted for height (body mass index [BMI]) in Australian HTRs.

METHODS

We recruited adult HTRs from Queensland's thoracic transplant clinic, 2020-2021. Study participants completed a 3-day food diary using a smart-phone app. Socio-demographic information was collected by self-administered questionnaire, and height, serial weight and clinical information were obtained from medical records. We calculated the Dietary Approaches to Stop Hypertension (DASH) index based on nine food groups and nutrients (index of 90 indicates highest possible quality), and any changes in BMI (≤ 0 kg m-2 or >0 kg m-2) post-transplantation. Median DASH index values were assessed in relation to sex and BMI change using Mann-Whitney U test.

RESULTS

Among 49 consented HTRs, 25 (51%) completed the food diary (median age 48 years, 52% females). Median BMI at enrolment was 27.2 kg m-2; median BMI change since transplant was +3.7 kg m-2. Fruit, vegetable, and whole grain intakes were generally lower than recommended, giving a low overall median DASH index of 30 with no sex differences. HTRs for which the BMI increased post-transplant had significantly lower median DASH indices than those whose BMI did not increase (30 vs. 45, p = 0.013).

CONCLUSIONS

The diet quality of HTRs appears suboptimal overall, with fruit and vegetable intakes especially low. HTRs whose BMI increased post-transplant had substantially lower quality diets than HTRs whose BMI did not increase.

Bioimpedance Spectroscopy in Heart Transplantation: Posttransplant Changes in Body Composition and Effects in Outcomes

BACKGROUND

Bioimpedance spectroscopy yields measurements of fat-free mass, fat mass, phase angle, and other measures. Bioimpedance spectroscopy has been validated as a preoperative assessment tool in cardiac surgical studies, in which low phase angle predicted morbidity and mortality. No studies have evaluated bioimpedance spectroscopy following heart transplantation.

METHODS

We evaluated body composition, nutrition status (Subjective Global Assessment, body mass index, midarm muscle circumference, and triceps skinfolds), and functional status (handgrip strength and 6-min walk test) in 60 adults. Body composition measurements via a 256-frequency bioimpedance spectroscopy device included fat and fat-free mass as well as phase angle calculated at 50 kHz. Testing was completed at baseline and 1, 3, 6, and 12 mo following heart transplantation. Mortality and hospital readmissions were analyzed.

RESULTS

Phase angle and fat mass increased while fat-free mass decreased; grip strength and 6-min walk test improved after transplantation (all P <  0.001). Improvement in phase angle in the first month postoperatively was associated with reduced risk of readmission. Low perioperative and 1-mo phase angles were associated with prolonged posttransplant length of stay (median: 13 versus 10 d, P =  0.03), increased infection-related readmissions (40% versus 5%, P =  0.001), and increased 4-y mortality (30% versus 5%, P =  0.01).

CONCLUSIONS

Phase angle, grip strength, and 6-min walk test distance improved after heart transplantation. Low phase angle appears to be associated with suboptimal outcomes and may be a feasible and affordable method to predict outcomes. Further research should ascertain whether preoperative phase angle can predict outcomes.

Long-term changes in body weight and serum cholesterol in heart transplant recipients

INTRODUCTION

Long-term changes in weight and blood lipids beyond 12 months after heart transplantation are largely unknown. We quantified changes in weight, body mass index (BMI), blood cholesterol, and triglycerides in heart transplant recipients (HTRs) during the 36 months after transplantation, and we assessed the influence of statin therapy on these outcomes.

METHODS

Retrospective cohort study of adult HTRs, transplanted 1990-2017, in Queensland, Australia. From each patient's medical charts, we extracted weight, total cholesterol, triglycerides, and statin therapy at four time-points: time of transplant (baseline), and 12-, 24-, 36-month post-transplant. Changes in weight and blood lipids were assessed according to baseline BMI.

RESULTS

Among 316 HTRs, 236 (median age 52 years, 83% males) with available information were included. During the 36 months post-transplant, all patients gained weight (83.5-90.5 kg; p < .001), especially those with baseline BMI < 25.0 km/m2 (67.9-76.2 kg; p < .001). Mean blood cholesterol (4.60-4.90 mmol/L; p = .004) and mean blood triglycerides (1.79-2.18 mmol/L; p = .006) also increased significantly in all patients, particularly in those with baseline BMI ≥ 25.0 km/m2 but the differences were not significant (total cholesterol 4.42-5.13 mmol/L; triglycerides 1.76-2.47 mmol/L). Total cholesterol was highest in patients not taking statins, and levels differed significantly (p = .010) according to statin dosing changes during the 36 months post-transplant.

CONCLUSION

Patients demonstrate significant rises in weight and blood lipids in the 36 months after heart transplantation.