Evaluation and treatment of patients with cardiac disease undergoing bariatric surgery

Bariatric Surgery in Patients with Previous Cardiac Revascularization: Review of Literature

Background: The diet and physical activity of the world's population determine the increase in the number of bariatric surgeries. The most common types of bariatric surgery are laparoscopic sleeve gastrectomy (LSG) and Roux-Y gastric bypass (RYGB). Surgical interventions are carried out in patients with numerous comorbidities, among which the most common are cardiovascular diseases. The aim of the present study was to review the literature regarding the safety and results of surgical treatment in patients with cardiac revascularization prior to surgery. Methods: We performed an online search in Pubmed in September 2023 to identify articles that reported cardiac revascularization prior to bariatric surgery. The extracted information included details of the working method, number of patients, types of cardiovascular disease-heart failure (HF) and cardiac artery disease (CAD), types of revascularization-coronary artery bypass graft (CABG), percutaneous coronary intervention (PCI) or both CABG + PCI, demographic data (age, gender, race), clinical characteristics (body mass index-BMI, smoking status), comorbidities (diabetes mellitus, hypertension, prior myocardial infarction), postoperative complications, and postoperative results. Results: A total of 171 records were identified by the initial search, and 165 papers were excluded after applying the exclusion criteria (types of cardiovascular disease, types of revascularization, and demographic data). We evaluated a group of 9479 patients of which 730 had HF, 2621 CAD, and 1426 underwent prior cardiac revascularization. The analysis of the demographic data showed an average age of 55.5 years and a fluctuation of the male gender between 39% and 71.1%, and the female gender between 28.9% and 61%. The main types of bariatric interventions were RYGB (3659 cases) and LSG (659 cases), to which adjustable gastric band (AGB) and bilio-pancreatic diversion-duodenal switch (BPD-DS) were added. Among the most postprocedural complications were ST-segment elevation myocardial infarction (2 patients), gastro-intestinal bleeding (51 cases), pulmonary embolism (1 patient), arrhythmia (3 patients) and pacemaker insertion (1 patient). The recorded postoperative mortality rate was 0.42% (6 cases). Conclusions: Bariatric surgery remains safe in patients with cardiac revascularization. These finding need to be confirmed in more large-scale randomized trials.

Preoperative cardiac screening using NT-proBNP in obese patients 50 years and older undergoing bariatric surgery: a study of 310 consecutive patients

Background

Obesity is associated with cardiovascular (CV) risk factors and diseases. Because bariatric surgery is increasingly performed in relatively elderly patients, a risk for pre- and postoperative CV complications exists.

Objectives

We aimed to assess the value of plasma N-terminal-probrain natriuretic peptide (NT-proBNP) as a CV screening tool.

Setting

High-volume bariatric center.

Methods

Between June 2019 and January 2020, all consecutive bariatric patients 50 years and older underwent preoperative NT-proBNP assessment in this cohort study to screen for CV disease. Patients with elevated NT-proBNP (≥125 pg/mL) were referred for further cardiac evaluation, including electrocardiography and echocardiography.

Results

We included 310 consecutive patients (median age, 56 years; 79% female; body mass index = 43±6.5 kg/m²). A history of CV disease was present in 21% of patients, mainly atrial fibrillation (7%) and coronary artery disease (10%). A total of 72 patients (23%) had elevated NT-proBNP levels, and 67 of them underwent further cardiac workup. Of these 67 patients, electrocardiography (ECG) showed atrial fibrillation in 7 patients (10%). On echocardiography, 3 patients had left ventricular ejection fraction (LVEF) <40%, 9 patients had LVEF 40%–49%, and 13 patients had LVEF ≥50% with structural and/or functional remodeling. In 2 patients, elevated NT-proBNP prompted workup leading to a diagnosis of coronary artery disease and consequent percutaneous coronary intervention in 1 patient.

Conclusions

Elevated NT-proBNP levels are present in 23% of patients 50 years and older undergoing bariatric surgery. In 37% of them, there was echocardiographic evidence for structural and/or functional remodeling. Further studies are needed to assess if these preliminary results warrant routine application of NT-proBNP to identify patients at risk for CV complications after bariatric surgery.

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This study assessed NT-proBNP as a cardiac screening tool in bariatric patients.

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Elevated NT-proBNP levels were present in 23% of patients ≥50 years.

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In 37% of them (n=25), echocardiography showed LV dysfunction or heart failure.

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NT-proBNP is a non-invasive tool that can detect new CV diseases in bariatric patients

Cardiac structure and function before and after bariatric surgery: a clinical overview

Obesity, defined as a body mass index of ≥30 kg/m² , is the most common chronic metabolic disease worldwide and its prevalence has been strongly increasing. Obesity has deleterious effects on cardiac function. The purpose of this review is to evaluate the effects of obesity and excessive weight loss due to bariatric surgery on cardiac function, structural changes and haemodynamic responses of both the left and right ventricle.

Perioperative fluid guidance with transthoracic echocardiography and pulse-contour device in morbidly obese patients

BACKGROUND

In bariatric surgery, non- or mini-invasive modalities for cardiovascular monitoring are addressed to meet individual variability in hydration needs. The aim of the study was to compare conventional monitoring to an individualized goal-directed therapy (IGDT) regarding the need of perioperative fluids and cardiovascular stability.

METHODS

Fifty morbidly obese patients were consecutively scheduled for laparoscopic bariatric surgery (ClinicalTrials.gov Identifier: NCT01873183). The intervention group (IG, n=30) was investigated preoperatively with transthoracic echocardiography (TTE) and rehydrated with colloid fluids if a low level of venous return was detected. During surgery, IGDT was continued with a pulse-contour device (FloTrac™). In the control group (CG, n=20), conventional monitoring was conducted. The type and amount of perioperative fluids infused, vasoactive/inotropic drugs administered, and blood pressure levels were registered.

RESULTS

In the IG, 213 ± 204 mL colloid fluids were administered as preoperative rehydration vs. no preoperative fluids in the CG (p<0.001). During surgery, there was no difference in the fluids administered between the groups. Mean arterial blood pressures were higher in the IG vs. the CG both after induction of anesthesia and during surgery (p=0.001 and p=0.001).

CONCLUSIONS

In morbidly obese patients suspected of being hypovolemic, increased cardiovascular stability may be reached by preoperative rehydration. The management of rehydration should be individualized. Additional invasive monitoring does not appear to have any effect on outcomes in obesity surgery.

Morbid obesity and optimization of preoperative fluid therapy

BACKGROUND

Preoperative venous return (VR) optimization and adequate blood volume is essential in management of morbidly obese patients (MO) in order to avoid perioperative circulatory instability. In this study, all subjects underwent a preoperative 3-week preparation by rapid-weight-loss-diet (RWL) as part of their treatment program for bariatric surgery.

METHODS

This is a prospective, observational study of 34 morbidly obese patients consecutively scheduled for bariatric surgery at Sunderby County Hospital, Luleå, Sweden. Preoperative transthoracic echocardiography (TTE) was performed in the awake state before and after intravascular volume challenge (VC) of 6 ml colloids/kg ideal body weight (IBW). Effects of standardized VC were evaluated by TTE. Dynamic and non-dynamic echocardiographic indices for VC were studied. Volume responsiveness and level of VR before and after VC were assessed by TTE. An increase of stroke volume ≥13% was considered as a volume responder.

RESULTS

Twenty-nine out of 34 patients were volume responders. After VC, a majority of patients (23/34) were euvolemic, and only 2/34 were hypovolemic. Post-VC hypervolemia was observed in 9/34 of patients.

CONCLUSIONS

The IBW-based volume challenge regime was found to be suitable for preoperative rehydration of RWL-prepared MO. Most of the patients were volume responders. Preoperative state of VR was not associated with volume responsiveness. IBW estimates and appropriate monitoring avoids potential hyperhydration in MO. For VC assessment, conventional Doppler indices were found to be more suitable compared to tissue Doppler, giving sufficient information on pressure-volume correlation of the left ventricle in morbidly obese.

Where to begin and where to end? Preoperative assessment for patients undergoing metabolic surgery

Bariatric surgery is the most effective treatment of obesity and its associated diseases like type 2 diabetes mellitus. Given the obesity epidemic and the efficacy of surgical treatment, the number of surgical weight loss procedures has grown in recent years. Nevertheless, there is little consensus regarding the extent of preoperative investigations required prior to patients undergoing surgery. This article aims to discuss the available evidence on which preoperative tests are useful for the detection and treatment of conditions such as venous thromboembolism, obstructive sleep apnea syndrome and Helicobacter pylori-positive gastritis prior to an operation. The present literature suggests that only a few preoperative investigations are essential, but that preoperative multidisciplinary care is beneficial.