Improved cardiometabolic outcomes after laparoscopic sleeve gastrectomy in a heart transplant patient; a case report

Abstract

Background

Bariatric surgery is recognized as a viable strategy for treatment of severe obesity in organ transplant recipients. There are limited reports regarding the surgical experience of bariatric surgery in patients who have undergone heart transplantation.

Case presentation

A 42-year-old male heart transplant recipient with Class II obesity underwent laparoscopic sleeve gastrectomy (LSG) at Namazi Tertiary Hospital in Shiraz, Iran, to manage post-transplant weight gain and mitigate cardiac transplant rejection risks. Post-operatively, the patient showed notable improvements in cardiac structure and function, including decreased left ventricular dimensions and enhanced tricuspid annular plane systolic excursion. Metabolic parameters stabilized, exemplified by normalized fasting blood sugars and reduced HbA1c levels. Improvements in liver and kidney function also allowed for lowered immunosuppressant dosages. These results demonstrate the potential of LSG to not only enhance cardiac function and metabolic stability but also reduce the need for immunosuppression, underscoring its viability as a strategy to improve transplant outcomes and quality of life.

Conclusion

The case highlights the importance of collaborative care and further research to assess long-term benefits in similar patient populations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-025-05101-z.

Introduction

Heart transplant recipients often experience significant weight gain post-transplantation, a condition linked to increased risks of cardiac allograft vasculopathy (CAV) and graft rejection, which can adversely affect both graft and patient survival [1, 2]. Effective management of this weight gain is crucial, as it is a modifiable risk factor that directly impacts long-term outcomes [3, 4]. While bariatric surgery is recognized as a viable strategy for severe obesity in organ transplant recipients, including procedures like laparoscopic gastric banding post-heart transplant [5], reports on specific outcomes within this patient population remain sparse. This case report details the first known instance of laparoscopic sleeve gastrectomy performed on a heart transplant recipient in Iran, exploring its impacts on post-transplant health and potential implications for managing transplant-related complications.

Case presentation

A 42-year-old male, previously diagnosed with dilated cardiomyopathy, underwent a heart transplant for end-stage heart failure at Abu Ali Sina Transplant Hospital, Shiraz, Iran, on March 13, 2021. Post-transplant, the patient was prescribed a regimen including cyclosporine (1000 mg twice daily) and tacrolimus (5 mg twice daily), along with prednisolone (40 mg daily) and trimethoprim-sulfamethoxazole (1600/320 mg daily). Despite adherence to this immunosuppressive regimen, he developed Class II obesity (BMI 35.5 kg/m²), which elevated his risk for transplant rejection and associated complications.

Given the significant weight gain and emerging pre-diabetic indicators by October 2022, a multidisciplinary team of heart failure cardiologists and bariatric surgeons recommended a laparoscopic sleeve gastrectomy. The procedure was performed on May 6, 2023, using four ports and 6 endoGIA purple stapler 60 mm. Stapler line reinforced using Prolene sutures on bougie size 32 french. Intraoperative cardiac monitoring was conducted by the anesthesia team. Postoperatively, the patient experienced transient hypertension, managed with intravenous nitroglycerin. He commenced oral hydration on the day after surgery and progressed to a liquid diet by the fourth day.

The patient was discharged in stable condition with adjustments to his immunosuppressive drugs based on frequent monitoring. Additionally, nutritional supplementation was initiated 15 days post-operation to support recovery and metabolic management. The adjustments and ongoing management were designed to minimize risks related to medication malabsorption and ensure stable postoperative recovery.

Results

Cardiac function assessment

Following the heart transplant, echocardiographic evaluation revealed progressive cardiac remodeling, marked by increased left ventricular end-systolic (LVESD) and end-diastolic diameters (LVEDD) from 24 mm and 40 mm initially to 28.2 ± 2.7 mm and 49.0 ± 4.9 mm, respectively, by the second post-transplant year. Post-gastrectomy follow-up showed significant improvements with a reduction in LVESD and LVEDD, indicating effective left ventricular remodeling. Post-sleeve gastrectomy follow-up showed significant improvements with a reduction in LVESD and LVEDD, indicating effective left ventricular remodeling and decreased ventricular diameter. Other cardiac parameters such as interventricular septal thickness and posterior wall thickness remained stable, suggesting no additional cardiac workload. The left ventricular ejection fraction improved to 60%, and right ventricular function, measured by tricuspid annular plane systolic excursion, also showed marked improvement. The left atrial diameter initially expanded from 41 mm to 62 mm post-transplant, a potential indicator of transplant rejection risk, but reduced to 50 mm following bariatric surgery, with further decreases anticipated. Mitral valve E’ velocity, a critical measure of diastolic function, improved from 6.1 cm/s to 7.5 cm/s after surgery. Similarly, the mitral E/e’ ratio stabilized, underscoring improvements in diastolic function and ventricular filling pressures. The patient’s systolic pulmonary artery pressure, aortic and pulmonic valves, and aortic measurements remained within normal limits throughout the study period. Additionally, the patient experienced a minor pericardial effusion after the heart transplant, which resolved prior to bariatric surgery. Please refer to Table 1 for more detailed information on the echocardiographic assessments.

Table 1.

Echocardiographic measures during the course of the study

EchoParameters	Unit	Initial Evaluation Post-Transplant	1st Year Post-Transplant	2nd Year Post-Transplant	Pre-Bariatric Surgery	1st Year Post-Bariatric Surgery	Last Follow-Up in the 1st Year
LVESD	mm	24	30.3	28.2	24	26.5	24
LVEDD	mm	40	45.7	49.0	42	47.0	46
IVST	mm	11	9.1	9.6	10	9.2	9
PWT	mm	10	9.1	10.	10	9.2	10
LVEF	%	55	57.3	58.0	60	60.0	60
RV diameter	mm	34	33.1	35.2	32	33	38
TAPSE	mm	14	15.3	13.4	12	18.0	17
LA diameter	mm	41	49.4	46.4	53	48.7	50
MV-E	cm/s	90	91.0	80.0	83	91.3	91
MV-E'	cm/s	10	8.4	6.9	7.8	7.3	7.5
Mitral E/e'	ratio	9	11.4	11.6	10.6	12.3	12
MV-A	cm/s	70	89.5	79.5	62	84	111
TV-SPAP	mmHg	25	21.6	22.0	30	23.7	25
Aorta root	mm	32	28.8	30	31	30.5	32
Asc.A	mm	30	28.4	28.2	30	29	30

Abbreviations: LVESD (Left Ventricular End-Systolic Diameter) - mm, LVEDD (Left Ventricular End-Diastolic Diameter) - mm, IVST (Interventricular Septal Thickness) - mm, PWT (Posterior Wall Thickness) - mm, LVEF (Left Ventricular Ejection Fraction) - %, RV (Right Ventricular) Diameter - mm, TAPSE (Tricuspid Annular Plane Systolic Excursion) - mm, LA (Left Atrial) Diameter - mm, MV-E (Early Diastolic Mitral Inflow Velocity) - cm/s, MV-e’ (Early Diastolic Mitral Annulus Velocity) - cm/s, E/e’ Ratio (Ratio of Early Diastolic Mitral Inflow Velocity to Early Diastolic Mitral Annulus Velocity), MV-A (Late Diastolic Mitral Annulus Velocity) - cm/s, TV-SPAP (Tricuspid Valve Systolic Pulmonary Artery Pressure) - mmHg, Aorta Root Measurements - mm, Asc.A (Ascending Aorta) Measurements - mm

Normal interval of echocardiographic parameters based on our institutional protocol: 

• TAPSE > 16 mm

• E-wave velocity: 0.6–0.8 m/s or 60–80 cm/s

• E’: ≥8 cm/s

• E/e’ ratio < 8; ratio > 15 indicates an increase in LV filling pressure

• SPAP: ≤ 25 mmHg

Notes:

• E-wave velocity reflects the early diastolic LA-LV pressure gradient or LA pressure in early diastole.

• E’ wave represents early diastolic filling.

• A-wave velocity reflects the late diastolic LA-LV pressure gradient or blood flow generated by active atrial contraction.

Improved laboratory parameters

Significant enhancements were observed in systemic and metabolic health, as shown in Table 2. Fasting blood sugar levels normalized from a pre-diabetic state, accompanied by reductions in HbA1c levels, indicating improved glycemic control. Improvements in liver function tests and renal function were noted, and nutritional markers such as albumin and vitamin B12 levels increased. Ferritin levels significantly decreased, suggesting a potential reduction in iron stores; although, iron supplement was prescribed post-sleeve gastrectomy. Tacrolimus (Prograf) levels varied, indicating adjustments in medication, but not necessarily implying an improvement in transplant function or rejection risk.

Table 2.

Baseline, preoperative, and follow-up characteristics of the case report

Characteristics	Unit	Baseline Post-transplant	Pre-sleeve gastrectomy	Mid-Follow-up (6months)	Last Follow-up (1year)
Weight	Kg	90–100	110	79	86
BMI	Kg/m2	29-32.2	35.4	25.4	27.7
WBC	103/µL	7.1	6.92	5.75	5.08
Hb	g/dL	12.5	15.5	15.1	14.6
MCV	fL	81.6	85.2	85	84.3
PLT	103/µL	217	181	197	183
Tacrolimus	ng/mL	6.1	-	3.8	6.9
BUN	mg/dL	17	12	14	13
Cr	mg/dL	1.16	0.99	1.13	1.03
FBS	mg/dL	108	125	86	91
HbA1c	% Hb	-	7.1	-	5.8
TG	mg/dL	-	118	-	124
HDL	mg/dL	-	50	59	67
LDL	mg/dL	-	131	95	127
LDL/HDL	Ratio	-	2.62	1.64	1.9
Alb	g/dL	-	4.4	-	4.7
AST (SGOT)	U/L	-	59	-	20
ALT (SGPT)	U/L	-	120	-	22
TSH	uIU/ml	-	1.73	1.61	1.96
T3	ng/ml	-	1.1	-	1.4
T4	µg/dL	-	9.9	-	5.2
Ferritin	ng/mL	-	209.3	-	68.5
PTH	pg/mL	-	75	-	65.8
Vit B12	pg/mL	-	275	-	370
Vit D3	ng/mL	26.1	29.8	31.4	23.8
Zn	µg/dL	-	92	-	77
Iron	µg/dL	-	84	-	80

Abbreviations and normal laboratory test results based on our institutional protocol: BMI (Body Mass Index), WBC (White Blood Cell, Reference Range: 4.0–10.0 × 10³/µL), Hb (Hemoglobin), MCV (Mean Corpuscular Volume, Reference Range: 80.0–96.0 fL), Tacrolimus or Prograf (Method: CLIA, Therapeutic Drug Monitoring: 5–20 ng/mL), BUN (Blood Urea Nitrogen, Method: Urease, Adult Reference Range: 7.0–24 mg/dL), Cr (Creatinine, Method: Jaffe, Adult Male Reference Range: 0.7–1.3 mg/dL), FBS (Fasting Blood Sugar, Method: Hexokinase, Reference Range: Normal: 70–99, Prediabetic: 100–125, Diabetic: ≥126), HbA1c (Glycated Hemoglobin, Method: HPLC, Reference Range: 3.8–5.7 (non-diabetic), 5.7–6.4 (prediabetic), > 6.4 (diabetic), < 7 (good diabetic control), 7–8 (poor diabetic control), > 8.0 (treatment failure)), TG (Triglycerides, Method: GPO-PAP, Reference Range (ATP III Classification): <150 (normal), 150–199 (borderline), 200–499 (high), > 500 (very high)), HDL-Cholesterol (Method: Direct, Reference Range: 30–63 (age < 60 years), 30–75 (age > 60 years)), LDL-Cholesterol (Method: Direct, Unit: mg/dL, Reference Range: <130 (adult)), LDL/HDL (Atherogenic Index, Reference Interval: <2.0 (low risk), 2.0–3.0 (weak risk), 3.0–5.0 (moderate risk), > 5.0 (high risk)), Alb (Albumin, Method: BCG, Reference Range: 3.5–5.2 (adult)), SGOT (AST, Method: DGKC, Reference Range: up to 40 (men)), SGPT (ALT, Method: DGKC, Reference Range: up to 41 (men)), TSH (Thyroid-Stimulating Hormone, Method: ECL, Reference Range: 0.27–5.2 (euthyroid adults), 5.2-7 (equivocal), > 7.0 (hypothyroidism)), T3 (Triiodothyronine, Method: CLIA, Reference Range: 0.7–2.04 (20–50 years)), T4 (Thyroxine, Method: CLEIA, Reference Range: 5.0-14.5 (euthyroid adults)), Ferritin (Method: ECL, Reference Interval: 30–400 (men)), PTH (Parathyroid Hormone, Method: ECL, Reference Interval: 15–65), Vitamin B12 (Method: CLIA, Reference Interval: 187–883), 25-OH Vit. D3 (Method: ELISA, Reference Interval: <20 (deficient), 20–29 (insufficient), 30–100 (sufficient), > 100 (toxic)), Zn (Zinc, Method: Atomic Absorption, Reference Range: 72.6–127 (men)), Iron (Method: Ferene, Reference Range: 33–193 (adult))

Drug doses adjustments

On April 7, 2024, the patient reported a weight of 86 kg at the same height. Following bariatric surgery, medication adjustments were made, including reductions in cyclosporine and tacrolimus doses. Previously administered medications, such as Prednisolone and trimethoprim-sulfamethoxazole, were discontinued. Notably, the doses of cyclosporine and tacrolimus were decreased from higher levels 1000 mg BID to 500 mg BID and 5 mg BID to 1.5 mg BID respectively. These adaptations highlight the indirect impact of bariatric surgery on medication management, further contributing to the patient’s improved health outcomes. Figure 1 shows the patient’s photo pre- and post-operative at the last follow-up.

Fig. 1.

Panels A and B display the patient’s photographs taken at the preoperative and postoperative stages, respectively. These images highlight the visible transformation and significant weight loss achieved following surgery. The patient also reported a notable improvement in quality of life postoperatively

Discussion

Heart transplant recipients are prone to significant post-transplant weight gain, which exacerbates the risk of cardiac allograft vasculopathy (CAV) and graft rejection [1, 2, 6]. Managing this weight gain is critical, as it directly impacts patient outcomes and graft survival [7, 8]. Weight-reducing drug therapies such as sibutramine and orlistat are contraindicated in severe cardiac disease [5], and orlistat has been shown to significantly reduce serum cyclosporine levels in heart transplant patients [9]. Bariatric surgery, particularly laparoscopic methods such as sleeve gastrectomy, has emerged as an effective intervention for morbid obesity in transplant recipients. Despite the global paucity of extensive clinical trials, several case reports [5, 10–14], including this one, affirm the benefits of such surgical approaches in enhancing post-transplant health. The successful implementation of bariatric surgery in heart transplant patients underscores its potential to mitigate weight-related complications and improve overall health. However, it presents unique perioperative challenges, particularly concerning the maintenance of adequate immunosuppression. Issues such as altered gastrointestinal anatomy could potentially affect the absorption of immunosuppressive medications, although significant problems have not been documented in heart transplant recipients to date [11, 13, 14]. Ablassmaier et al. [5] in a case report, stated that laparoscopic adjustable gastric banding (LAGB) did not affect cyclosporine dosage in a heart transplant recipient. Notably, laparoscopic sleeve gastrectomy has been shown to maintain stable immunosuppression levels, achieve significant weight loss, and enhance the management of comorbidities without compromising graft function [15]. Consistent with these findings, a notable observation in our case report was the adjustment of the immunosuppressive regimen, particularly the reduction in tacrolimus and cyclosporine doses approximately one year post-surgery. However, it is crucial to exercise caution, and close monitoring of immunosuppressive drug levels is necessary for all transplant recipients undergoing bariatric surgery. Additionally, the risk of bariatric surgery complications such as infections and leakage must be carefully considered, particularly in transplant recipients receiving immunosuppressive therapies [16]. On another note, the calcineurin inhibitors cyclosporine and tacrolimus have the potential to induce diabetes [7], necessitating attention.

New-onset diabetes after transplantation can be challenging to manage and may contribute, along with hypertension and hyperlipidaemia, to the development of ischemic heart disease, cerebrovascular disease, and peripheral vascular disease [7]. Moreover, our case illustrates marked improvements in metabolic control following surgery, with significant reductions in fasting blood sugar and HbA1c levels, suggesting effective management of new-onset diabetes often associated with post-transplant medication regimens. These metabolic improvements are likely facilitated by hormonal changes induced by bariatric surgery, which aid in better glucose regulation and can decrease the necessity for diabetes medications [17–19]. Significant weight loss and resolution of diabetes mellitus have been reported in heart transplant patients following bariatric surgery [11–14]. Our case witnessed postoperative improvements in laboratory parameters, including normalized fasting blood sugar and HbA1c levels, enhanced liver function tests, stabilized renal function, and improved immune response, oxygen transport, and calcium-phosphorus metabolism.

The integration of echocardiographic data into our case report further strengthens the evidence of significant cardiac benefits following bariatric surgery in a heart transplant patient with a complex cardiac history. A recent study by Henry et al. [20] demonstrated that Laparoscopic Sleeve Gastrectomy (LSG) and Roux-en-Y Gastric Bypass (RYGB) result in significant reductions in left ventricular mass (LVM), left ventricular mass ratio (LVMVR), and epicardial adipose tissue (EAT) compared to Laparoscopic Adjustable Gastric Band (LAGB). Similarly, our patient’s postoperative echocardiographic follow-up revealed improvements, including notable decreases in left ventricular end-systolic diameter (LVESD) and left ventricular end-diastolic diameter (LVEDD), as well as enhanced tricuspid annular plane systolic excursion (TAPSE). These results align with the significant reductions in LVM and improvements in left ventricular geometry observed in patients undergoing LSG as reported in the study.

Additionally, another study assessed electrocardiographic changes post-bariatric surgery, highlighting improvements in QTc interval, right ventricular hypertrophy (RVH), and R wave progression [21]. Our case report supports these findings, as our patient showed enhanced cardiac function and structure, reflecting the broader cardiovascular benefits of LSG even in heart transplant patients with obesity-related comorbidities.

Nowadays Glucagon-like peptide analogue (GLP)−1, (like Semagutide) may recommend for controlling weight recurrence and diabetes relapse after bariatric surgery [22]. It has also proven that Semaglutide can have anti-inflammatory effects by inhibiting the release of pro-inflammatory cytokines, such as IL-6 and TNF-α and also will protect the cardiovascular system by improving cardiac function, vascular structure and promoting ventricular thickening through its anti-inflammatory effects [23].

Based on the results of the aforementioned studies, it may be concluded that the use of these medications after bariatric surgery, especially in patients with a history of heart transplantation, can be highly effective in both maintaining weight loss and reducing the need for immunosuppressive drugs in the post-surgery period. To date, no specific drug interactions between these medications and immunosuppressive drugs have been reported in the studies.

To the best of our knowledge, this is the first report of laparoscopic sleeve gastrectomy in a heart transplant patient in Iran. The documented improvements in metabolic parameters, including normalized fasting blood sugars and reduced HbA1c levels, as well as enhanced liver and kidney function, allowed for lowered immunosuppressant dosages. Tacrolimus is a vital component in the post heart transplant period and ongoing monitoring is essential to prevent side effects and balancing the efficacy. Based on our heart transplant cardiologists guideline, the drug monitoring post heart transplant is daily in the first two weeks (acceptable dosage,10–15 ng/mL), then weekly for the next two months(6–10 ng/mL), monthly for the next 9 months (5–8 ng/mL) and after the first year post transplant, tacrolimus dosage should be kept between 4 and 6 ng/ml in routine monthly assessment. Approximately one and half year following the heart transplant, our patient underwent sleeve gastrectomy. In accordance with our mentioned protocol, monthly monitoring of immunosuppressant drug levels was continued. Considering that the standard therapeutic target range one-year post-transplant is 4 to 6ng/ml, we successfully achieved and maintained this therapeutic level at both six months(3.8ng/ml) and one year after the bariatric surgery(6.9ng/ml), despite a gradual reduction in drug dosage.

Given the patient’s stable cardiac condition three months after sleeve gastrectomy, the cardiologist decided to discontinue trimethoprim-sulfamethoxazole and prednisolone was tapered, with treatment being continued on dual immunosuppressive regime. These outcomes underscore the potential of LSG to not only enhance cardiac function and metabolic stability but also reduce the need for immunosuppression, mitigating the risks of transplant rejection and tissue damage.

There are limited reports worldwide regarding bariatric surgery in patients with a history of heart transplantation, all of which have been conducted in American academic surgical centers and are referenced accordingly [5, 10–14].

Conclusion

This case report suggests that sleeve gastrectomy may be a viable option for heart transplant recipients with moderate to severe obesity who also have associated conditions that adversely affect graft survival and quality of life. We acknowledge the high-risk nature of this patient population and stress the importance of close collaboration between the bariatric surgical team and the transplant cardiologist to ensure patient safety and optimize outcomes. Considering the surgical outcomes in the aforementioned studies and the patient discussed in our research, it may be possible to establish a comprehensive and effective guideline for these specific patients, allowing for a substantiated claim that the results of these cases can be representative of a change in clinical guidance and should be applied to more patients in our country. Considering that only one year had passed since our patient follow up at the time of writing article, Further research with a larger number of patients is warranted to investigate the long-term outcomes of graft survival, complications, weight loss durability and efficacy of bariatric surgery in this unique population.

Authors’ contributions

All the authors (Masood Amini, Nader Moeinvaziri, Hossein Hosseini, Hamed Bazrafshandrissi, Neda Haghighat, Behzad Rezaei) made significant contribution to the work and reviewed the final manuscript.

Funding

None.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

not applicable.

Consent for publication

An informed consent was obtained from the patient to publish the details of his medical record and his photos.

Competing interests

The authors declare no competing interests.