Heart Transplant and Hepato-Renal Dysfunction: The Model of End-Stage Liver Disease Excluding International Normalized Ratio as a Predictor of Postoperative Outcomes

Association between early postoperative hypoalbuminaemia and outcome after orthotopic heart transplantation

OBJECTIVES

In patients undergoing heart transplantation (HTX), preoperative liver impairment and consecutive hypoalbuminaemia are associated with increased mortality. The role of early postoperative hypoalbuminaemia after HTX is unclear. This study investigated the association between early postoperative hypoalbuminaemia and 1-year mortality as well as 'days alive and out of hospital' (DAOH) after HTX.

METHODS

This retrospective cohort study included patients who underwent HTX at the University Hospital Duesseldorf, Germany, between 2010 and 2022. The main exposure was serum albumin concentration at intensive care unit (ICU) arrival. The primary endpoints were mortality and DAOH within 1 year after surgery. Receiver operating characteristic (ROC) curve analysis was performed and logistic and quantile regression models with adjustment for 13 a priori defined clinical risk factors were conducted.

RESULTS

Out of 241 patients screened, 229 were included in the analysis (mean age 55 ± 11 years, 73% male). ROC analysis showed moderate discrimination for 1-year mortality by postoperative serum albumin after HTX [AUC = 0.74; 95% confidence interval (CI): 0.66-0.83]. The cutoff for serum albumin at ICU arrival was 3.0 g/dl. According to multivariate logistic and quantile regression, there were independent associations between hypoalbuminaemia and mortality/DAOH [odds ratio of 4.76 (95% CI: 1.94-11.67) and regression coefficient of -46.97 (95% CI: -83.81 to -10.13)].

CONCLUSIONS

Postoperative hypoalbuminaemia <3.0 g/dl is associated with 1-year mortality and reduced DAOH after HTX and therefore might be used for early postoperative risk re-assessment in clinical practice.

Effect of Preoperative Right Ventricular Dysfunction on Heart Transplantation Outcomes

BACKGROUND

We investigated if the occurrence of preoperative right ventricular dysfunction is capable of influencing heart transplant results in terms of in-hospital mortality, incidence of primary graft dysfunction, and follow-up mortality.

METHODS

We retrospectively analyzed 517 patients who underwent heart transplant between January 2000 and December 2020. We defined right ventricular dysfunction (RVD), as central venous pressure (CVP) > 15 mm Hg and CVP/pulmonary capillary wedge pressure ratio > 0.63. We identified 2 subgroups in our population: 33 patients with preoperative RVD and 484 patients without RVD.

RESULTS

In-hospital mortality was 7.9%. Severe early graft failure occurred in 6.6% of patients, with 26 patients (5.1%) needing intra-aortic balloon pump and 17 patients (3.3%) needing extracorporeal membrane oxygenation support. Clinical variables that significantly influenced in-hospital mortality were age, peripheral artery disease, and bilirubin > 1.5 mg/dL, while hemodynamic variables influencing in-hospital mortality were CVP (odds ratio [OR], 1.09 [confidence interval {CI}, 1.03-1.15], P = .004], pulmonary artery systolic pressure (OR, 1.02 [CI, 1.00-1.04], P = .05), CVP/pulmonary capillary wedge pressure ratio (OR, 2.78 [CI, 1.14-6.80], P = .025), pulmonary vascular resistance (OR, 1.15 [CI, 1.01-1.32], P = .042), transpulmonary gradient (TPG) (OR, 1.11 [CI, 1.03-1.18], P = .003) , diastolic transpulmonary gradient (OR, 1.10 [CI, 1.02-1.20], P = .015], together with right ventricular dysfunction (OR, 3.56 [CI, 1.44-8.80], P = .011). On the other hand, clinical variables influencing the incidence of early graft failure were body mass index (calculated as weight in kilograms divided by height in meters squared) > 30, peripheral artery disease, bilirubin > 1.5 mg/dL, Model for End-Stage Liver Disease score excluding international normalized ratio before transplant, and preoperative extracorporeal membrane oxygenation support, while hemodynamic variables were pulmonary arterial systolic pressure (OR, 1.03 [CI, 1.00-1.05], P = .016), TPG (OR, 1.08 [1.01-1.17], P = .03), and right ventricular dysfunction (OR, 3.00 [CI, 1.07-8.40] P = .046). On the multivariable analysis, RVD and TPG were independent predictors of in-hospital mortality, while only TPG was a predictor of early graft failure. Follow-up mortality was 38.7% and was influenced by recipient age, recipient body mass index, and preoperative diabetes. Moreover, 1-, 5-, and 10-year survival of patients with preoperative RVD was significantly worse than patients without RVD (log-rank = 0.001).

CONCLUSIONS

In our population, RVD influenced both in-hospital and long-term results after heart transplant. For these reasons, it appears crucially important to optimize preoperative right ventricular function to improve these patients' outcomes.

Child-Turcotte-Pugh versus MELD-XI identify distinct high-risk populations for heart transplantation following ventricular assist device placement

BACKGROUND

Patients with end-stage heart failure frequently have significant congestive hepatopathy requiring hepatology assessment prior to heart transplantation listing. An elevated Model for End-stage Liver Disease score with modification to exclude INR (MELD-XI) has been associated with increased mortality following heart transplantation (HT). This study's primary aim was to examine whether Child-Turcotte-Pugh (CTP) classification is associated with post-transplant mortality in patients bridged to transplant with left ventricular assist devices.

METHODS AND RESULTS

We conducted a retrospective analysis of 134 patients from our center. Age, CTP class, and MELD-XI at HT were included in the multivariate model for the primary outcome, which demonstrated a significant association between 1-year mortality and CTP class (CTP-A HR: .08, CI .01-.46, P < .01; CTP-B HR: .25, CI .05-1.2, P = .08; reference group CTP-C), and MELD-XI (HR: 1.15; CI: 1.03-1.28; P = .01), but no significant difference for age (HR: .97; CI: .93-1.01; P = .15). Only 13/33 patients with CTP improvement after assist device also had improvement in MELD-XI.

CONCLUSIONS

Patients with relatively low MELD-XI scores with discordantly high CTP classification may be a distinct subset for whom MELD-XI underestimates the risk of mortality after heart transplantation compared to CTP.

MELD score is predictive of 90-day mortality after veno-arterial extracorporeal membrane oxygenation support

BACKGROUND

The Model for End-Stage Liver Disease (MELD) score was originally described as a marker of survival in chronic liver disease. More recently, MELD and its derivatives, MELD excluding INR (MELD-XI) and MELD with sodium (MELD-Na), have been applied more broadly as outcome predictors in heart transplant, left ventricular assist device placement, heart failure, and cardiogenic shock, with additional promising data to support the use of these scores for prediction of survival in those undergoing veno-arterial extracorporeal membrane oxygenation (VA ECMO).

METHODS

This study assessed the prognostic impact of MELD in patients with cardiogenic shock undergoing VA ECMO via a single-center retrospective review from January 2014 to March 2020. MELD, MELD-XI, and MELD-Na scores were calculated using laboratory values collected within 48 h of VA ECMO initiation. Multivariate Cox regression analyses determined the association between MELD scores and the primary outcome of 90-day mortality. Receiver operating characteristics (ROC) were used to estimate the discriminatory power for MELD in comparison with previously validated SAVE score.

RESULTS

Of the 194 patients, median MELD was 20.1 (13.7-26.2), and 90-day mortality was 62.1%. There was a significant association between MELD score and mortality up to 90 days (hazard ratio (HR) = 1.945, 95% confidence interval (95% CI) = 1.244-3.041, p = 0.004) after adjustment for age, indication for VA ECMO, and sex. The prognostic significance of MELD score for 90-day mortality revealed an AUC of 0.645 (95% CI = 0.565-0.725, p < 0.001). MELD-Na score and MELD-XI score were not associated with mortality.

CONCLUSION

MELD score accurately predicts long-term mortality and may be utilized as a valuable decision-making tool in patients undergoing VA ECMO.

Comparison of Scores for Child-Pugh Criteria and Standard and Modified Models for End-Stage Liver Disease to Assess Cardiac Hepatopathy in Heart Transplant Recipients

OBJECTIVES

Congestive hepatopathy as a result of advanced heart failure correlates with poor outcomes. Thus, risk-scoring systems have been established to assess the risks for cardiac surgery and hearttransplant, although these systems were originally designed to measure mortality risk in patients with end-stage liver disease. We compared the scores for the Child-Pugh criteria andstandardandmodifiedModels for End-Stage LiverDisease to evaluate the effect of preoperative liver dysfunction on postoperative outcomes inpatients with heart failure who underwent heart transplant.

MATERIALS AND METHODS

Data of 60 consecutive patients who underwent orthotopic heart transplant were analyzed from a historical cohort study from January 1, 2015, to December 31, 2018. We calculated the scores for Child-Pugh criteria and the standard and modified Models for End-Stage Liver Disease.

RESULTS

Of the 60 total patients, 48 were male patients, with a median age of 43 years (range, 13-69 years). Twenty patients died before the end of the study. The causes of death were cardiac, liver, and renal diseases. The mortality risk increased 25% (interquartile range, 0.05-0.51) for the patients with 1 point higher score compared with the patients with 1 point lower score based on a modified Model for End-Stage Liver Disease (P = .01).

CONCLUSIONS

Preoperative liver dysfunction has a significant effect on patient survival. The modified Modelfor End-Stage LiverDisease scoring system could be an effective predictor of perioperative risk stratification for patients with congestive hepatopathy who are undergoing cardiac transplant.

Pretransplant Right Ventricular Dysfunction Is Associated With Increased Mortality After Heart Transplantation: A Hard Inheritance to Overcome

BACKGROUND

Right ventricular dysfunction (RVD) is a major issue in patients with advanced heart failure because it precludes the implantation of left ventricular assist device, usually leaving heart transplantation (HTx) as the only available treatment option. The pulmonary artery pulsatility index (PAPi) is a hemodynamic parameter integrating information of right ventricular function and of pulmonary circulation. Our aim is to evaluate the association of preoperative RVD, hemodynamically defined as a low PAPi, with post-HTx survival.

METHODS AND RESULTS

Consecutive adult HTx recipient at 2 Italian transplant centers between 2000 and 2018 with available data on pre-HTx right heart catheterization were included retrospectively. RVD was defined as a value of PAPi lower than the 25th percentile of the study population. The association of RVD with the 1-year post-HTx mortality and other secondary end points were evaluated. Multivariate logistic regression was used to adjust for clinical and hemodynamic variables. Analyses stratified by pulmonary vascular resistance (PVR) status (≥3 Woods units vs <3 Woods units) were also performed. Among 657 HTx recipients (female 31.1%, age 53 ± 11 years), patients with pre-HTx RVD (PAPi of <1.68) had significantly lower 1-year survival rates (77.8% vs 87.1%, P = .005), also after adjusting for estimated glomerular filtration rate, total bilirubin, PVR, serum sodium, inotropes, and mechanical circulatory support at HTx (hazard ratio 2.0, 95% confidence interval, 1.3-3.1). RVD was also associated with post-HTx renal replacement therapy (hazard ratio 2.0, 95% confidence interval 1.05-3.30) and primary graft dysfunction (hazard ratio 1.7, , 95% confidence interval 1.02-3.30). When stratifying patients by estimated PVR status, RVD was associated with worse 1-year survival among patients with normal PVR (76.9% vs 88.3%, P = .003), but not in those with increased PVR (78.6% vs 83.2%, P = .49).

CONCLUSIONS

Preoperative RVD, evaluated through PAPi, is associated with mortality and morbidity after HTx, providing incremental prognostic value over traditional clinical and hemodynamic parameters.

Statistical performance of 16 posttransplant risk scores in a contemporary cohort of heart transplant recipients

Accurate risk stratification of early heart transplant failure is required to avoid futile transplants and rationalize donor selection. We aimed to evaluate the statistical performance of existing risk scores on a contemporary cohort of heart transplant recipients. After an exhaustive search, we identified 16 relevant risk scores. From the UNOS database, we selected all first noncombined adult heart transplants performed between 2014 and 2017 for validation. The primary endpoint was death or retransplant during the first year posttransplant. For all scores, we analyzed their association with outcomes, sensitivity, specificity, likelihood ratios, and discrimination (concordance index and overlap of individual scores). The cohort included 9396 patients. All scores were significantly associated with the primary outcome (P < .001 for all scores). Their likelihood ratios, both negative and positive, were poor. The discriminative performance of all scores was limited, with concordance index ranging from 0.544 to 0.646 (median 0.594) and an important overlap of individual scores between patients with or without the primary endpoint. Subgroup analyses revealed important variation in discrimination according to donor age, recipient age, and the type of assist device used at transplant. Our findings raise concerns about the use of currently available scores in the clinical field.

Donor risk analysis and validation in heart transplants: a single-centre experience

OBJECTIVES

A heart transplant (Htx) remains the gold standard treatment for patients with advanced heart failure. Considering the limited availability of organs, donor risk scores might improve organ selection and allocation. The objective of the study was to compare United Network for Organ Sharing, RADIAL and Eurotransplant scoring models in calculating post-Htx outcomes in an Italian Htx population.

METHODS

Between January 2000 and December 2017, a total of 461 adult patients underwent Htxs. United Network for Organ Sharing, RADIAL and Eurotransplant scores were calculated. Clinical features and donor risk scores were tested to identify preoperative, intraoperative and postoperative risk variables and eventually validate the scores on our population.

RESULTS

Early graft failure was detected in 16.1% (74/461). Post-Htx extracorporeal life support was used in 11.1% (51/461). Of the donor-related factors, the use of noradrenaline (P = 0.015) negatively influenced early outcomes, whereas an ischaemic time >240 min (P = 0.037) influenced early graft failure occurrence. The Eurotransplant donor score did not impact outcomes; the RADIAL score significantly influenced both early and late mortality; and the United Network for Organ Sharing score influenced only late mortality. On the multivariable analysis, after adjustment of scores per cohort, noradrenaline infusion was the main independent predictor of in-hospital mortality for the donors, whereas age of the recipient [odds ratio (OR) 1.003, 1.003-1.081; P = 0.032] and use of preoperative extracorporeal membrane oxygenation (OR 3.320, 1.124-9.805; P = 0.030) were the main independent predictors for the recipients.

CONCLUSIONS

None of the validated donor scoring systems fully behave as reliable predictors of transplant outcomes. According to our 'local only' graft selection, specific donor and recipient risk variables should be monitored in order to predict early and late outcomes satisfactorily.

Mechanically Supported Early Graft Failure After Heart Transplantation

BACKGROUND

The occurrence of early graft failure (EGF) after heart transplantation (Htx) often requires a mechanical circulatory support (MCS) therapy. The aims of our study were to identify risk factors of mechanically supported severe EGF and evaluate their impact on both early and late outcomes.

METHODS

Between January 2000 and December 2019, 499 consecutive adult patients underwent Htx at our institution. Severe EGF was defined as the need for extracorporeal life support (ECLS) within 24 hours after surgery. All available recipient and donor variables were retrospectively analyzed.

RESULTS

Overall, EGF occurred in 58 (11.6%) patients. Post-Htx peripheral or central ECLS was necessary in 32 (6.4%) cases. Independent predictors of severe EGF were, in the recipient group, preoperative transpulmonary gradient (TPG) >12 mm Hg (odds ratio [OR] 4.1, P = .013), preoperative inotropic score >10 (OR 7.3, P = .0001), and pre-Htx ECLS support (OR 5.2, P = .015), while in the donors, a Eurotransplant donor score ≥17 (OR 8.5, P = .005). The absence of EGF was related with a better survival at 1 year and 5 years (94% and 85%, respectively) compared with EGF requiring ECLS population (36% and 28% at 1 year and 5 years, respectively; P < .001). A five-year conditional survival rate did not differ significantly (85% no EGF vs 83% EGF requiring ECLS).

CONCLUSION

Both donor and recipient factors may influence EGF occurrence. Post-Htx ECLS may impact negatively early; however, patients weaned from ECLS eventually benefit from such a rescue treatment with outcomes comparable with Htx patients who did not suffer EGF.