Elevated High-Sensitivity Troponin I During Living Donor Liver Transplantation Is Associated With Postoperative Adverse Outcomes

Markers of cardiac injury in patients with liver cirrhosis

Liver cirrhosis is an increasing public health problem and a major cause of morbidity and mortality. Accordingly, cirrhotic cardiomyopathy, a frequently underdiagnosed condition, is becoming a growing health problem. In the last 20 years, cardioselective biomarkers have been investigated for their diagnostic and prognostic properties for numerous conditions. The aim of this article is to review the literature on the relationship between the most commonly used cardioselective biomarkers (cardiac troponins I and T, N-terminal pro-B-type natriuretic peptide, brain natriuretic peptide, and heart-type fatty-acid binding protein) and the presence, functional stage, and clinical outcomes of liver cirrhosis. Elevated plasma levels of these biomarkers have been reported in patients with liver cirrhosis, and there is mounting evidence on their predictive value for clinical outcomes in this disease. In addition, elevated plasma levels of these biomarkers have been reported in patients before, during, and after liver transplantation, but in fewer studies. Due to their predictive value for clinical outcomes, we advocate the use of these markers in patients with liver cirrhosis and cirrhotic cardiomyopathy, as well as in candidates for liver transplant.

Meta-analysis of postoperative myocardial injury as a predictor of mortality after living donor liver transplantation

BACKGROUND

The purpose of this study was to perform a systematic review and meta-analysis to investigate postoperative myocardial injury, as expressed by the postoperative concentration of high-sensitivity cardiac troponin I (hs-cTnI) as a predictor of mortality among living donor liver transplantation (LDLT) patients.

METHODS

PubMed, Scopus, Embase and the Cochrane Library were searched through to September 1st 2022. The primary endpoint included in-hospital mortality. Secondary endpoints were 1-year mortality and re-transplantation occurrence. Estimates are expressed as risk ratios (RRs) and 95% confidence intervals (95% CIs). Heterogeneity was assessed with the I² test.

RESULTS

During the search, 2 studies were found that fit the criteria and had a total of 527 patients. Pooled analysis showed that in-hospital mortality in patients with myocardial injury was 9.9%, compared to 5.0% for patients without myocardial injury (RR = 3.01; 95% CI: 0.97-9.36; p = 0.06). Mortality among 1-year follow-up was 5.0% vs. 2.4%, respectively (RR = 1.90; 95% CI: 0.41-8.81; p = 0.41).

CONCLUSIONS

In recipients with normal preoperative cTnI, myocardial injury LDLT may be associated with adverse clinical outcomes during a hospital stay, but the results were inconsistent at 1-year follow-up. Although routine follow-up of postoperative hs-cTnI, even in patients with normal preoperative levels, might still help predict the clinical outcome of LDLT. In future large and more representative studies are needed to establish the potential role of cTns in perioperative cardiac risk stratification.

Temporary postoperative myocardial injury and long-term survival in liver transplant patients with coronary artery disease

Background: Coronary artery disease (CAD) is increasing worldwide due to the aging population and cardiometabolic syndrome. However, the extent of postoperative myocardial injury, the most common cause of death during the 30 days after noncardiac surgery, remains unclear with respect to liver transplant (LT) patients with CAD. We examined the link between post-LT high sensitivity cardiac troponin I (hs_cTnI) and long-term survival according to liver disease severity.Methods: Consecutive patients who underwent LT (n = 3,220) from 2010 to 2020 were evaluated retrospectively. CAD was defined as a history of coronary artery bypass surgery or percutaneous intervention, or previous myocardial infarction. Peak hs_cTnI levels within 30 days post-transplant were compared in patients with and without CAD. The primary endpoint was defined as an all-cause mortality at 12 years following LT. Secondary endpoints include peak hs_cTnI level within post-transplant 30 days and 30-day mortality. Survival analysis was performed using the Kaplan–Meier method.Results: CAD patients (n = 264, 8.2%) had higher peak hs_cTnI levels within 30 days post-LT than those without CAD (median [interquartile]: 0.068 [0.030–0.154] vs. 0.087 [0.037–0.203] ng/ml, respectively; P = 0.004); however, the mortality rate was comparable (14.7% vs. 14.8%, respectively, P = 0.999), at 12 years, and 1.9% vs. 1.1% (P = 0.522) at 30 days, respectively, at 30 days. Subgroup analysis with stratified liver disease severity identified a similar risk of long-term mortality.Conclusions: Although the peak hs_cTnI level within 30 days was higher in revascularized or treated CAD patients after LT compared those without CAD, long-term mortality rates at 12 years and 30-day mortality rate were comparable.

Cardiovascular events after liver transplantation: MACE hurts

The curative therapy for patients with end-stage liver disease is liver transplantation. However, liver transplantation challenges the cardiovascular system, and is associated with major adverse cardiovascular events (MACE). Immediately after implantation of the liver graft, changes in cardiac preload and afterload increase the cardiac workload. Longer-term postoperatively, a more sedentary lifestyle and enhanced appetite increase obesity and body mass index. Immunosuppressants may also affect the cardiovascular system. All these factors that liver recipients encounter impact the function of the cardiovascular system. Cardiac events are the third-leading cause of death in liver recipients. This review describes the pertinent factors that predispose to development of MACE after liver transplantation, and how to predict these cardiovascular events in the post-transplant period. We review the roles of metabolic syndrome, renal dysfunction, non-alcoholic fatty liver disease, diagnostic tests such as imaging and biomarkers, and parameters such as systolic and diastolic dysfunction, and QT interval prolongation in cardiovascular events. We summarize the current literature on scoring systems to predict cardiovascular events.

Association between Cardiologist Consultation and Mortality of Stable Patients with Elevated Cardiac Troponin at Admission

Elevated cardiac troponin (cTn) showed associations with mortality even in stable patients, but management has not been established. We aimed to investigate whether consultation to cardiologists could reduce mortality of stable patients with cTn elevation at admission. We identified 1329 patients with elevated cTn level at hospitalization from outpatient clinic to any department other than cardiology or cardiac surgery between April 2010 and December 2018. The patients were divided into two groups according to cardiologist consultation at admission. For primary outcome, mortality during one year was compared in the crude and propensity-score-matched populations. In 1329 patients, 397 (29.9%) were consulted to cardiologists and 932 (70.1%) were not. Mortality during the first year was significantly lower in patients consulted to cardiologists compared with those who were not (9.8% vs. 14.2%; hazard ratio (HR), 0.50; 95% confidence interval (CI), 0.35-0.72; p < 0.001). After propensity-score matching, 324 patients were in the cardiologist consultation group and 560 patients were in the no cardiologist consultation group. One-year mortality was consistently lower in the cardiologist consultation group (10.5% vs. 14.6%; HR, 0.58; 95% CI, 0.39-0.86; p = 0.01). Cardiologist consultation may be associated with lower mortality in stable patients with cTn elevation at admission. Further studies are needed to identify effective management strategies for stable patients with elevated cTn.

Myocardial injury in noncardiac surgery

Myocardial injury is defined as an elevation of cardiac troponin (cTn) levels with or without associated ischemic symptoms. Robust evidence suggests that myocardial injury increases postoperative mortality after noncardiac surgery. The diagnostic criteria for myocardial injury after noncardiac surgery (MINS) include an elevation of cTn levels within 30 d of surgery without evidence of non-ischemic etiology. The majority of cases of MINS do not present with ischemic symptoms and are caused by a mismatch in oxygen supply and demand. Predictive models for general cardiac risk stratification can be considered for MINS. Risk factors include comorbidities, anemia, glucose levels, and intraoperative blood pressure. Modifiable factors may help prevent MINS; however, further studies are needed. Recent guidelines recommend routine monitoring of cTn levels during the first 48 h post-operation in high-risk patients since MINS most often occurs in the first 3 days after surgery without symptoms. The use of cardiovascular drugs, such as aspirin, antihypertensives, and statins, has had beneficial effects in patients with MINS, and direct oral anticoagulants have been shown to reduce the mortality associated with MINS in a randomized controlled trial. Myocardial injury detected before noncardiac surgery was also found to be associated with postoperative mortality, though further studies are needed.

Prediction of Perioperative Cardiovascular Events in Liver Transplantation

BACKGROUND

Hepatorenal syndrome (HRS) is a serious complication of liver cirrhosis with poor survival in the absence of liver transplantation (LT). HRS represents a state of profound circulatory and cardiac dysfunction. Whether it increases risk of perioperative major adverse cardiovascular events (MACE) following LT remains unclear.

METHODS

We performed a retrospective cohort study of 560 consecutive patients undergoing cardiac workup for LT of whom 319 proceeded to LT. All patients underwent standardized assessment including dobutamine stress echocardiography. HRS was defined according to International Club of Ascites criteria.

RESULTS

Primary outcome of 30-day MACE occurred in 74 (23.2%) patients. A significantly higher proportion of patients with HRS experienced MACE (31 [41.9%] versus 54 [22.0%]; P = 0.001). After adjusting for age, model for end-stage liver disease score, cardiovascular risk index, history of coronary artery disease, and a positive stress test, HRS remained an independent predictor for MACE (odds ratio [OR], 2.44; 95% confidence interval [CI], 1.13-5.78). Other independent predictors included poor functional status (OR, 3.38; 95% CI, 1.41-8.13), pulmonary hypertension (OR, 3.26; 95% CI, 1.17-5.56), and beta-blocker use (OR, 2.56; 95% CI, 1.10-6.48). Occurrence of perioperative MACE was associated with a trend toward poor age-adjusted survival over 3.6-year follow-up (hazard ratio, 2.0; 95% CI, 0.98-4.10; P = 0.057).

CONCLUSIONS

HRS, beta-blocker use, pulmonary hypertension, and poor functional status were all associated with over a 2-fold higher risk of MACE following LT. Whether inclusion of these variables in routine preoperative assessment can facilitate cardiac risk stratification warrants further study.

Mildly Elevated Cardiac Troponin below the 99th-Percentile Upper Reference Limit after Noncardiac Surgery

BACKGROUND AND OBJECTIVES

In patients with perioperative cardiac troponin (cTn) I below the 99th-percentile upper range of limit (URL), mortality according to cTn I level has not been fully evaluated. This study evaluated the association between postoperative cTn I level above the lowest limit of detection but within the 99th-percentile URL and 30-day mortality after noncardiac surgery.

METHODS

Patients with cTn I values below the 99th-percentile URL during the perioperative period were divided into a no-elevation group with cTn I at the lowest limit of detection (6 ng/L) and a minor elevation group with cTn I elevation below the 99th percentile URL (6 ng/L < cTn I < 40 ng/L). The primary outcome was 30-day mortality.

RESULTS

Of the 5,312 study participants, 2,582 (48.6%) were included in the no-elevation group and 2,730 (51.4%) were included in the minor elevation group. After propensity score-matching, the minor elevation group showed significantly increased 30-day mortality (0.5% vs. 2.3%; hazard ratio, 4.30; 95% confidence interval, 2.23-8.29; p<0.001). The estimated cutoff value of cTn I to predict 30-day mortality was 6 ng/L with the area under the receiver operating characteristic curve 0.657.

CONCLUSIONS

A mild elevation of cTn I within the 99th-percentile URL after noncardiac surgery was significantly associated with increased 30-day mortality as compared with the lowest limit of detection.

TRIAL REGISTRATION

Clinical Research Information Service Identifier: KCT0004244.

Preoperative high-sensitivity troponin I and B-type natriuretic peptide, alone and in combination, for risk stratification of mortality after liver transplantation

Background

Given the severe shortage of donor liver grafts, coupled with growing proportion of cardiovascular death after liver transplantation (LT), precise cardiovascular risk assessment is pivotal for selecting recipients who gain the greatest survival benefit from LT surgery. We aimed to determine the prognostic value of pre-LT combined measurement of B-type natriuretic peptide (BNP) and high-sensitivity troponin I (hsTnI) in predicting early post-LT mortality.

Methods

We retrospectively evaluated 2,490 consecutive adult LT patients between 2010 and 2018. Cut-off values of BNP and hsTnI for predicting post-LT 90-day mortality were calculated. According to the derived cut-off values of two cardiac biomarkers, alone and in combination, adjusted hazard ratios (aHR) of post-LT 90-day mortality were determined using multivariate Cox regression analysis.

Results

Mortality rate after 90 days was 2.9% (72/2,490). Rounded cut-off values for post-LT 90-day mortality were 400 pg/ml for BNP (aHR 2.02 [1.15, 3.52], P = 0.014) and 60 ng/L for hsTnI (aHR 2.65 [1.48, 4.74], P = 0.001), respectively. Among 273 patients with BNP ≥ 400 pg/ml, 50.9% of patients were further stratified into having hsTnI ≥ 60 ng/L. Combined use of pre-LT cardiac biomarkers predicted post-LT 90-day mortality rate; both non-elevated: 1.0% (21/2,084), either one is elevated: 9.0% (24/267), and both elevated: 19.4% (27/139, log-rank P < 0.001; aHR vs non-elevated 4.23 [1.98, 9.03], P < 0.001).

Conclusions

Concomitant elevation of both cardiac biomarkers posed significantly higher risk of 90-day mortality after LT. Pre-LT assessment cardiac strain and myocardial injury, represented by BNP and hsTnI values, would contribute to prioritization of LT candidates and help administer target therapies that could modify early mortality.

Five-lead Electrocardiography During Living Donor Liver Transplantation: Incidence and Clinical Significance of ST Segment Abnormality

OBJECTIVES

Five-lead electrocardiography (ECG) is commonly used during liver transplantation, while 3-lead ECG is used during most noncardiac operations. This study aimed to evaluate the incidence and clinical significance of ST segment abnormality during living donor liver transplantation (LDLT) with 5-lead ECG.

METHODS

We retrospectively reviewed medical records of patients who received LDLT between May 2018 and May 2019. A total of 109 adult recipients underwent LDLT, and 108 recipients were divided into 2 groups according to whether or not significant ST segment abnormality had occurred at 8 predetermined time points during the operation. ST segment change by more than 1 mm was regarded as significant.

RESULTS

Of the 108 recipients, 21 recipients (19.4%) had significant ST segment depression during the operation. No case of significant ST segment elevation was noted. The significant ST segment depression was detected mostly in lead II and V5, and with 2 in combination we could detect 95.2% of significant ST segment change. The significant ST segment depression was frequently observed 1 hour after anhepatic phase and 2 hours after reperfusion. Patient characteristics were not different between the 2 groups. Moreover, the cardiac enzyme (troponin I) measurements, measured immediately after the operation, were not different between the 2 groups.

CONCLUSIONS

Although significant ST segment change was frequently observed during LDLT, more studies are required to determine the clinical significance of 5-lead ECG ST segment abnormality during LDLT.

Intraoperative Troponin Elevation in Liver Transplantation Is Independently Associated With Mortality: A Prospective Observational Study

Intraoperative factors implicated in postoperative mortality after liver transplantation (LT) are poorly understood. Because LT is a particularly demanding procedure, we hypothesized that intraoperative myocardial injury may be frequent and independently associated with early postoperative outcomes. We aimed to determine the association between intraoperative high-sensitivity troponin (hsTn) elevation during LT and 30-day postoperative mortality. A total of 203 adult patients undergoing LT were prospectively included in the cohort and followed during 1 year. Advanced hemodynamic parameters and serial high-sensitivity troponin T (hsTnT) measurements were assessed at 6 intraoperative time points. The optimal hsTnT cutoff level for intraoperative troponin elevation (ITE) was identified. Patients were classified into 2 groups according to the presence of ITE. Independent impact of ITE on survival was assessed through survival curves and multivariate Cox regression analysis. Intraoperative cardiac function was compared between groups. Troponin levels increased early during surgery in the ITE group. Troponin values at abdominal closure were associated with 30-day mortality (area under the receiver operating caracteristic curve, [AUROC], 0.73; P = 0.005). Patients with ITE showing values of hsTnT ≥61 ng/L at abdominal closure presented higher 30-day mortality (29.6% versus 3.4%; P < 0.001). ITE was independently associated with 30-day mortality (hazard ratio, 3.8; 95% confidence interval, 1.1-13.8; P = 0.04) and with worse overall intraoperative cardiac function. The hsTnT upper reference limit showed no discriminant capacity during LT. Intraoperative myocardial injury identified by hsTn elevation is frequently observed during LT, and it is associated with myocardial dysfunction and short-term mortality. Determinations of hsTn may serve as a valuable intraoperative monitoring tool during LT.

Pretransplant left ventricular hypertrophy in association with postoperative myocardial injury in liver transplantation

Pretransplant left ventricular hypertrophy (LVH) is a common finding during preoperative cardiac evaluation. We hypothesized that patients with pretransplant LVH were associated with a higher risk of postoperative myocardial injury (PMI) in adult patients undergoing liver transplantation (LT). A retrospective cohort analysis was performed by reviewing the medical records of adult patients who underwent LT between January 2006 and October 2013. Of 893 patients, the incidences of mild, moderate, and severe LVH were 7.8%, 5.6%, and 2.5%, respectively. Propensity match was used to eliminate the pretransplant imbalance between the LVH and non-LVH groups. In after-match patients, 23.5% of LVH patients developed PMI compared to 11.8% in the control group (P = .011). The incidence of PMI in patients with moderate-severe degrees of LVH was significantly higher compared with that in patients with mild LVH (27.9% vs 19.1%, P = .016). When controlling intraoperative variables, patients with LVH had 4.5 higher odds of developing PMI (95% CI1.18-17.19, P = .028). Patients experiencing PMI had significantly higher 1-year mortality (37.5% vs 15.7%, log-rank test P < .001). Our results suggest that patients with pretransplant LVH were at a high risk of developing PMI and should be monitored closely in the perioperative period. More studies are warranted.

Preoperative cardiac assessment in liver transplant candidates

New and extended indications, older age, higher cardiovascular risk, and the long-standing cirrhosis-associated complications mandate specific skills for an appropriate preoperative assessment of the liver transplant (LT) candidate. The incidence of cardiac diseases (dysrhythmias, cardiomyopathies, coronary artery disease, valvular heart disease) are increasing among LT recipients: however, no consensus exists among clinical practice guidelines for cardiovascular screening and risk stratification. In spite of different "transplant center-centered protocols", basic "pillars" are common (electrocardiography, baseline echocardiography, functional assessment). Owing to intrinsic limitations, yields and relevance of noninvasive stress tests, under constant scrutiny even if used, are discussed, focusing the definition of the "high risk" candidate and exploring noninvasive imaging and new forms of stress imaging. The aim is to find an appropriate and rational stepwise algorithm. The final commitment is to select the right candidate for a finite resource, the graft, able to save (and change) lives.

Postoperative Myocardial Injury Does Not Predict Early and 1-Year Mortality After Living Donor Liver Transplantation

BACKGROUND

Preoperative cardiac troponin-I (cTnI) elevation has been shown to be a predictor of mortality after liver transplantation. Myocardial injury after non-cardiac surgery (MINS) has been defined as elevation of serum cardiac troponin levels in the perioperative period that does not fulfill the criteria for myocardial infarction. MINS has been shown to be a prognostic factor for in-hospital and long-term mortality, but there is limited data in patients undergoing living-donor liver transplantation (LDLT). In this study, we aimed to evaluate the relationship between MINS and postoperative mortality.

MATERIAL AND METHODS

Patients who had undergone adult LDLT at Florence Nightingale Hospital Liver Transplantation Unit between December 2012 and December 2015 were retrospectively analyzed for 30-day in-hospital and 1-year mortality. Myocardial injury was defined as cTnI level above 0.04 ng/mL. Patients (N = 214) were divided into 2 groups according to postoperative cTnI levels. The following were the exclusion criteria: 1. patients under 18 years old, 2. patients undergoing deceased-donor liver transplantation or dual liver-kidney transplantation, 3. cTnI elevation due to other causes (sepsis, renal failure, pulmonary embolism, myocardial infarction), and 4. patients without postoperative troponin levels.

RESULTS

MINS occurred in 123 (57.4%) patients after LDLT. There was no difference between the groups according to age, sex, creatinine levels, presence of ischemic heart disease, hypertension, diabetes mellitus, and tobacco use. The presence of MINS did not predict 30-day and 1-year mortality in the study population.

CONCLUSION

Myocardial injury detected by serum cTnI elevation was frequent after LDLT; however, it was not associated with 30-day in-hospital and 1-year mortality.

Abdominal Organ Transplantation: Noteworthy Literature in 2018

A PubMed search revealed 1382 articles on pancreatic transplantation, 781 on intestinal transplantation, more than 7200 on kidney transplantation, and more than 5500 on liver transplantation published between January 1, 2018, and December 31, 2018. After narrowing the list down to human studies, 436 pancreatic, 302 intestinal, 1920 liver, and more than 2000 kidney transplantation studies were screened for inclusion in this review.