Prognostic value of coronary risk factors, exercise capacity and single photon emission computed tomography in liver transplantation candidates: A 5-year follow-up study

Outcomes of Coronary Artery Bypass Grafting (CABG) Patients With and Without a History of Liver Transplant

BACKGROUND

Liver transplant (LT) patients face various challenges, including an increased risk of coronary artery disease (CAD) for a variety of reasons, with 70% of LT recipients having one cardiovascular event. Coronary artery bypass grafting (CABG) remains one of the most commonly performed major surgical procedures in the United States, with 20-30% of LT patients requiring a CABG. Many studies have analyzed when to perform a CABG and CAD workup pre-LT, but this population remains a problem. The patient population is challenging to study due to their rarity and complexity. Our study aimed to compile many patients through the National Inpatient Sample (NIS) database to gauge the outcomes of CABG in patients with and without a history of LT.  Methods: Patients who underwent CABG with or without a history of LT were selected from the NIS from 2008 to 2020. The International Classification of Diseases (ICD) 9 and 10 codes were used to identify suitable records. Primary outcomes of interest were all-cause hospital mortality, shock, acute myocardial infarction, acute kidney injury (AKI), and a composite of these. Secondary outcomes included length of stay and total charges.  Results: A weighted total of 2,407,349 CABG hospitalizations were included in this study. Of these, 1,833 had a history of LT. Overall, patients with a history of LT were more likely to be younger (65.16 vs. 66.16; p<0.001), male (81.6% vs. 73.66%; p<0.001), and more complex (Charlson Comorbidity Index (CCI) 5.89 vs. 4.16; p<0.001) than patients without a history of LT. Patients with a history of LT also had higher rates of diabetes mellitus type 2 (57.02% vs. 43.39%; p<0.001), end-stage renal disease (11.21% vs. 2.95%; p<0.001), and gastroesophageal reflux disease (GERD) (28.39% vs. 21.26%; p<0.001). CABG patients with a history of LT were less likely, however, to have hyperlipidemia (56.72% vs. 74.26%; p<0.001), hypertension (25.95% vs. 58.45%; p<0.001), obesity (19% vs. 23.42%; p=0.046), a history of smoking (12.06% vs. 18.66%; p<0.01), or alcohol use disorder (9.04% vs. 13.44%; p=0.017). We found that patients admitted for CABG with a history of LT had significantly higher adjusted odds of mortality (OR 1.84; p<0.01), AKI (OR 2.65; p<0.001), and composite outcome (OR 2.04; p<0.001). They also experienced a longer length of stay (1.7 days; p=0.02) and greater hospital charges ($26,761; p=0.029).

CONCLUSION

We found that CABG patients with a history of LT had nearly twofold higher odds of mortality, nearly threefold higher odds of AKI, and twofold higher odds of composite outcomes than CABG patients without LT. This corresponded to longer lengths of stay and increased hospital charges. Patients should require lower thresholds for left heart catheterization and more strict CAD testing before an LT due to the increased risk of adverse outcomes with the current standard of care.

Impact of Pretransplant Diabetes on Outcomes After Liver Transplantation: An Updated Meta-analysis With Systematic Review

BACKGROUND

Preliver transplant diabetes mellitus (pre-LT DM) is a common comorbidity in LT recipients associated with poorer post-transplant survival. However, its relationship with other important outcomes, including cardiovascular and renal outcomes, remains unclear. This meta-analysis aims to provide an updated analysis of the impact of pre-LT DM on key post-LT outcomes.

METHODS

A search was conducted in Medline and Embase databases for articles comparing the post-transplant outcomes between patients with and without pre-LT DM. Pairwise analysis using random effects with hazard ratios (HRs) was used to assess the longitudinal post-LT impacts of pre-LT DM. In the absence of HR, pooled odds ratios analysis was conducted for secondary outcomes.

RESULTS

Forty-two studies involving 77,615 LT recipients were included in this analysis. The pooled prevalence of pre-LT DM amongst LT recipients was 24.79%. Pre-LT DM was associated with significantly lower overall survival (HR, 0.65; 95% confidence interval, 0.52-0.81; P <0.01) and significantly increased cardiovascular disease-related mortality (HR, 1.78; 95% confidence interval, 1.11-2.85; P =0.03). Meta-regression of other patient characteristics identified Asian ethnicity and hypertension to be significant predictors of worse overall survival, whereas African-American ethnicity was associated with significantly improved overall survival in patients with pre-LT DM. Further analysis of secondary outcomes revealed pre-LT DM to be a significant predictor of post-LT cardiovascular events and end-stage renal disease.

CONCLUSIONS

The present study illustrates the impact of pre-LT DM on post-LT survival, and cardiovascular and renal outcomes and provides a sound basis for revision of preoperative management of pre-LT DM.

Cardiac risk stratification of the liver transplant candidate: A comprehensive review

Cardiovascular diseases (CVD) form a principal consideration in patients with end-stage liver disease (ESLD) undergoing evaluation for liver transplant (LT) with prognostic implications in the peri- and post-transplant periods. As the predominant etiology of ESLD continues to evolve, addressing CVD in these patients has become increasingly relevant. Likewise, as the number of LTs increase by the year, the proportion of older adults on the waiting list with competing comorbidities increase, and the demographics of LT candidates evolve with parallel increases in their CVD risk profiles. The primary goal of cardiac risk assessment is to preemptively reduce the risk of cardiovascular morbidity and mortality that may arise from hemodynamic stress in the peri- and post-transplant periods. The complex hemodynamics shared by ESLD patients in the pre-transplant period with adverse cardiovascular events occurring in only some of these recipients continue to challenge currently available guidelines and their uniform applicability. This review focusses on cardiac assessment of LT candidates in a stepwise manner with special emphasis on preoperative patient optimization. We hope that this will reinforce the importance of cardiovascular optimization prior to LT, prevent futile LT in those with advanced CVD beyond the stage of optimization, and thereby use the finite resources prudently.

Cardiac imaging for the assessment of patients being evaluated for liver transplantation

Cardiac risk assessment prior to liver transplantation has become widely accepted. With the emergence of nonalcoholic steatohepatitis among the leading causes of end-stage liver disease and the steady rise of the age of liver transplant recipients, the burden of cardiovascular diseases has markedly increased in this population. Selecting appropriate liver transplant candidates is crucial due to the increasing demand for scarce donor organs. The use of noninvasive cardiac imaging for pre-operative assessment of the cardiovascular status of liver transplant recipients has been on the rise, yet the optimal assessment strategy remains an area of active debate. In this review, we examine the relevant literature pertaining to the diagnostic and prognostic applications of noninvasive cardiac imaging in this population. We also propose a simple literature-based evaluation algorithm for CAD surveillance in liver transplant candidates.

Preoperative Evaluation of Coronary Artery Disease in Liver Transplant Candidates: Many Unanswered Questions in Clinical Practice

Cardiovascular (CV) complications represent the first non-graft-related cause of death and the third overall cause of death among patients undergoing liver transplantation (LT). History of coronary artery disease is related to increased CV mortality following LT. Although it is of paramount importance to stratify CV risk in pre-LT patients, there is no consensus regarding the choice of the optimal non-invasive cardiac imaging test. Algorithms proposed by scientific associations include non-traditional risk factors, which are associated with increased cardiac risk profiles. Thus, an individualized pre-LT evaluation protocol should be followed. As the average age of patients undergoing LT and the number of candidates continue to rise, the “3 W” questions still remain unanswered, Who, Which and When? Who should be screened for coronary artery disease (CAD), which screening modality should be used and when should the asymptomatic waitlisted patients repeat cardiac evaluation? Prospective studies with large sample sizes are warranted to define an algorithm that can provide better risk stratification and more reliable survival prediction.