Prolonged QTc interval and its relationship to autonomic cardiovascular reflexes in patients with cirrhosis

Corrected QT interval in cirrhosis: A systematic review and meta-analysis

BACKGROUND

Corrected QT (QTc) interval is prolonged in patients with liver cirrhosis and has been proposed to correlate with the severity of the disease. However, the effects of sex, age, severity, and etiology of cirrhosis on QTc have not been elucidated. At the same time, the role of treatment, acute illness, and liver transplantation (Tx) remains largely unknown.

AIM

To determine the mean QTc in patients with cirrhosis, assess whether QTc is prolonged in patients with cirrhosis, and investigate whether QTc is affected by factors such as sex, age, severity, etiology, treatment, acute illness, and liver Tx.

METHODS

In the present systematic review and meta-analysis, the searching protocol "{[QTc] OR [QT interval] OR [QT-interval] OR [Q-T syndrome]} AND {[cirrhosis] OR [Child-Pugh] OR [MELD]}" was applied in PubMed, EMBASE, and Google Scholar databases to identify studies that reported QTc in patients with cirrhosis and published after 1998. Seventy-three studies were considered eligible. Data concerning first author, year of publication, type of study, method used, sample size, mean age, female ratio, alcoholic etiology of cirrhosis ratio, Child-Pugh A/B/C ratio, mean model for end-stage liver disease (MELD) score, treatment with β-blockers, episode of acute gastrointestinal bleeding, formula for QT correction, mean pulse rate, QTc in patients with cirrhosis and controls, and QTc according to etiology of cirrhosis, sex, Child-Pugh stage, MELD score, and liver Tx status (pre-Tx/post-Tx) were retrieved. The Newcastle-Ottawa quality assessment scale appraised the quality of the eligible studies. Effect estimates, expressed as proportions or standardized mean differences, were combined using the random-effects, generic inverse variance method of DerSimonian and Laird. Subgroup, sensitivity analysis, and meta-regressions were applied to assess heterogeneity. The study has been registered in the PROSPERO database (CRD42023416595).

RESULTS

QTc combined mean in patients with cirrhosis was 444.8 ms [95% confidence interval (CI): 440.4-449.2; P < 0.001 when compared with the upper normal limit of 440 ms], presenting high heterogeneity (I2 = 97.5%; 95%CI: 97.2%-97.8%); both Egger's and Begg's tests showed non-significance. QTc was elongated in patients with cirrhosis compared with controls (P < 0.001). QTc was longer in patients with Child-Pugh C cirrhosis when compared with Child-Pugh B and A (P < 0.001); Child-Pugh B patients presented longer QTc when compared with Child-Pugh A patients (P = 0.003). The MELD score was higher in patients with cirrhosis with QTc > 440 ms when compared with QTc ≤ 440 ms (P < 0.001). No correlation of QTc with age (P = 0.693), sex (P = 0.753), or etiology (P = 0.418) was detected. β-blockers shortened QTc (P< 0.001). QTc was prolonged during acute gastrointestinal bleeding (P = 0.020). Tx tended to improve QTc (P < 0.001). No other sources of QTc heterogeneity were revealed.

CONCLUSION

QTc is prolonged in cirrhosis independently of sex, age, and etiology but is correlated with severity and affected by β-blockers and acute gastrointestinal bleeding. QTc is improved after liver Tx.

Prolonged QT Interval in Cirrhosis: Twisting Time?

Approximately 30% to 70% of patients with cirrhosis have QT interval prolongation. In patients without cirrhosis, QT prolongation is associated with an increased risk of ventricular arrhythmias, such as torsade de pointes (TdP). In cirrhotic patients, there is likely a significant association between the corrected QT (QTc) interval and the severity of liver disease, and possibly with increased mortality. We present a stepwise overview of the pathophysiology and management of acquired long QT syndrome in cirrhosis. The QT interval is mainly determined by ventricular repolarization. To compare the QT interval in time it should be corrected for heart rate (QTc), preferably by the Fridericia method. A QTc interval >450 ms in males and >470 ms in females is considered prolonged. The pathophysiological mechanism remains incompletely understood, but may include metabolic, autonomic or hormonal imbalances, cirrhotic heart failure and/or genetic predisposition. Additional external risk factors for QTc prolongation include medication (IKr blockade and altered cytochrome P450 activity), bradycardia, electrolyte abnormalities, underlying cardiomyopathy and acute illness. In patients with cirrhosis, multiple hits and cardiac-hepatic interactions are often required to sufficiently erode the repolarization reserve before long QT syndrome and TdP can occur. While some risk factors are unavoidable, overall risk can be mitigated by electrocardiogram monitoring and avoiding drug interactions and electrolyte and acidbase disturbances. In cirrhotic patients with prolonged QTc interval, a joint effort by cardiologists and hepatologists may be useful and significantly improve the clinical course and outcome.

Autonomic Nervous System Profiling In Response to Liver Transplantation: Prognostic Evaluation and Preliminary Study

BACKGROUND

Liver cirrhosis leads to autonomic dysfunction (AD). We present a pilot study and review of published literature to investigate the long-term changes in the Autonomic Nervous System (ANS) of patients who underwent liver transplant. We propose Autonomic Function Tests (AFT) can be used as a predictor of liver transplant outcome.

METHODS

Twenty-eight patients (19 men and 9 women; mean age 45 years) with cirrhosis due to different etiologies underwent a noninvasive ANS evaluation test, pre- and post-liver transplant at 3 to 6 months, 8 to 12 months, and 14 to 24 months. Data were compared with 45 age-matched controls (14 men and 31 women). We investigated changes in the following 3 adrenergic measures: percentage of cutaneous vasoconstriction in the hand and foot in response to cold stress test and cutaneous blood flow adjustment ratio; and 3 cardiovagal measures: change in heart rate in relation to deep respiration, forced respiration represented as Valsalva Ratio, and head-up tilting (30/15 ratio).

RESULTS

A total of 23 of 28 patients (82%) had impairment in AFT before transplant, 16 of 28 (57%) in the sympathetic adrenergic measures, and 15 of 28 (54%) in the parasympathetic cardiovagal measures. There was a gradual improvement in ANS function posttransplant, with a significant improvement in the cardiovagal measure of Valsalva Ratio (P < .05 from baseline). These data suggest some temporary decline in ANS functions within the first 6 months posttransplant.

CONCLUSIONS

To optimize outcomes in liver transplant patients with autonomic dysfunction, autonomic testing perhaps combined with frailty testing can be used as objective measures of mortality in the pre-liver transplant stage.

Macroscopic T-wave alternans in a patient presenting with hepatic encephalopathy

Macroscopic T-wave alternans (TWA) is the beat-to-beat variation in the amplitude or shape of the T wave on a surface electrocardiogram (ECG) and known to be a harbinger of impending malignant ventricular arrhythmias such as polymorphic ventricular tachycardia. We herein report a case with hepatic encephalopathy, who developed TWA, followed by polymorphic ventricular tachycardia.

QTc prolongation in patients of cirrhosis and its relation with disease severity: An observational study from a rural teaching hospital

Introduction:

Cirrhotic cardiomyopathy is characterised by increased baseline cardiac output, systolic and diastolic dysfunction, diminished cardiovascular response to stressful stimuli and electrophysiological abnormalities in patients of cirrhosis in the absence of any underlying cardiac disease. QTc prolongation has been described as a common electrocardiographic abnormality in cirrhosis patients.

Aims and Objectives:

This study was done to evaluate the prevalence of QTc changes in patients of cirrhosis coming to a rural tertiary care centre and to analyse its correlation with disease severity.

Materials and Methods:

The present study was conducted on 100 patients suffering from cirrhosis of liver presented to the department of medicine. Around 100 age and sex-matched individuals were recruited as controls. The Child-Pugh score was used to determine the disease severity in cirrhosis patients. Standard 12-lead ECG was recorded in all cases and controls.

Results:

Prolongation of QTc interval on ECG was observed in the majority (80%) of cirrhosis patients and it was significantly higher as compared to the healthy controls (P <0.01). The prolongation of QTc was significantly associated with the duration of disease (P <0.05) and disease severity as measured by the Child-Pugh score (P <0.01).

Conclusion:

QTc prolongation on ECG may be an early marker of cardiac involvement in patients of cirrhosis and is significantly associated with disease severity.

Cardiac diastolic dysfunction predicts poor prognosis in patients with decompensated liver cirrhosis

BACKGROUND/AIMS

Left ventricular diastolic dysfunction (LVDD) is an early manifestation of cardiac dysfunction in patients with liver cirrhosis (LC). However, the effect of LVDD on survival has not been clarified, especially in decompensated LC.

METHODS

We prospectively enrolled 70 patients with decompensated LC, including ascites or variceal bleeding, at Daejeon St. Mary's Hospital from April 2013 to April 2015. The cardiac function of these patients was evaluated using 2D echocardiography with tissue Doppler imaging. The diagnosis of LVDD was based on the American Society of Echocardiography guidelines. The primary endpoint was overall survival.

RESULTS

Forty-four patients (62.9%) had LVDD. During follow-up (22.3 months), 18 patients died (16 with LVDD and 2 without LVDD). The survival rate was significantly lower in patients with LVDD than in those without LVDD (31.1 months vs. 42.6 months, P=0.01). In a multivariate analysis, the Child-Pugh score and LVDD were independent predictors of survival. Moreover, patients with a ratio of early filling velocity to early diastolic mitral annular velocity (E/e') ≥ 10 (LVDD grade 2) had lower survival than patients with E/e' ratio < 10.

CONCLUSION

The presence of LVDD is associated with poor survival in patients with decompensated LC. Therefore, it may be important to monitor and closely follow LVDD patients.

Q-T Interval Prolongation in Patients with Liver Cirrhosis

Liver cirrhosis (LC) is the end stage of chronic liver disease characterized by the appearance of extensive fibrosis and regeneration nodes associated with hepatocyte necrosis in liver but also by the reshuffling of hepatic architecture. The triad consisting of hepatic parenchymal necrosis, regeneration and scarring is always present regardless of the type of clinical manifestation. The Child-Pugh-Turcotte classification dates back more than 30 years and has been widely used in diagnosing and assessing the severity of liver cirrhosis. This is preferred due to a low degree of complexity and a good predictive value. Prolongation of the QT interval on the electrocardiogram is common, with a prevalence exceeding 60% in patients with advanced stage of cirrhosis. In these cases, beta blockers and antiarrhythmics should be avoided or used with caution and with close QT interval monitoring. Changes in heart rate and Q-T interval are new entities in cirrhosis complications. A prolonged Q-T interval in chronic liver disease could lead to ventricular arrhythmias and sudden death. There is no report on heart rate and Q-T interval disorders in our area.

Bilirubin acts as a multipotent guardian of cardiovascular integrity: more than just a radical idea

Bilirubin, a potentially toxic catabolite of heme and indicator of hepatobiliary insufficiency, exhibits potent cardiac and vascular protective properties. Individuals with Gilbert's syndrome (GS) may experience hyperbilirubinemia in response to stressors including reduced hepatic bilirubin excretion/increased red blood cell breakdown, with individuals usually informed by their clinician that their condition is of little consequence. However, GS appears to protect from all-cause mortality, with progressively elevated total bilirubin associated with protection from ischemic heart and chronic obstructive pulmonary diseases. Bilirubin may protect against these diseases and associated mortality by reducing circulating cholesterol, oxidative lipid/protein modifications, and blood pressure. In addition, bilirubin inhibits platelet activation and protects the heart from ischemia-reperfusion injury. These effects attenuate multiple stages of the atherosclerotic process in addition to protecting the heart during resultant ischemic stress, likely underpinning the profound reduction in cardiovascular mortality in hyperbilirubinemic GS. This review outlines our current knowledge of and uses for bilirubin in clinical medicine and summarizes recent progress in revealing the physiological importance of this poorly understood molecule. We believe that this review will be of significant interest to clinicians, medical researchers, and individuals who have GS.

Liver cirrhosis-effect on QT interval and cardiac autonomic nervous system activity

AIM

To examine the impact of liver cirrhosis on QT interval and cardiac autonomic neuropathy (CAN).

METHODS

A total of 51 patients with cirrhosis and 51 controls were examined. Standard 12-lead electrocardiogram recordings were obtained and QT as well as corrected QT interval (QTc) and their dispersions (dQT, dQTc) were measured and calculated using a computer-based program. The diagnosis of CAN was based upon the battery of the tests proposed by Ewing and Clarke and the consensus statements of the American Diabetes Association. CAN was diagnosed when two out of the four classical Ewing tests were abnormal.

RESULTS

QT, QTc and their dispersions were significantly longer (P < 0.01) in patients with cirrhosis than in controls. No significant differences in QT interval were found among the subgroups according to the etiology of cirrhosis. Multivariate regression analysis after controlling for age, gender and duration of cirrhosis demonstrated significant association between QT and presence of diabetes mellitus [standardized regression coefficient (beta) = 0.45, P = 0.02] and treatment with diuretics (beta = 0.55, P = 0.03), but not with the Child-Pugh score (P = 0.54). Prevalence of CAN was common (54.9%) among patients with cirrhosis and its severity was associated with the Child-Pugh score (r = 0.33, P = 0.02). Moreover, patients with decompensated cirrhosis had more severe CAN that those with compensated cirrhosis (P = 0.03). No significant association was found between severity of CAN and QT interval duration.

CONCLUSION

Patients with cirrhosis have QT prolongation. Treatment with diuretics is associated with longer QT. CAN is common in patients with cirrhosis and its severity is associated with severity of the disease.

Predictors of Cardiovascular Events After Liver Transplantation

Indications for liver transplant have been extended, and older and sicker patients are undergoing transplantation. Infectious, malignant, and cardiovascular diseases account for the most posttransplant deaths. Cirrhotic patients can develop heart disease through systemic diseases affecting the heart and the liver, cirrhosis-specific heart disease, or common cardiovascular. No single factor can predict posttransplant cardiovascular complications. Patients with history of cardiovascular disease, and specific abnormalities on echocardiography, electrocardiography, or serum markers of heart disease seem to be at increased risk of complications. Pretransplant cardiovascular evaluation is essential to detecting these risk factors so their effects can be mitigated through appropriate intervention.

QT prolongation is associated with increased mortality in end stage liver disease

AIM

To determine the prevalence of QT prolongation in a large series of end stage liver disease (ESLD) patients and its association to clinical variables and mortality.

METHODS

The QT interval was measured and corrected for heart rate for each patient, with a prolonged QT cutoff defined as QT > 450 ms for males and QT > 470 ms for females. Multiple clinical variables were evaluated including sex, age, serum sodium, international normalized ratio, creatinine, total bilirubin, beta-blocker use, Model for End-Stage Liver Disease (MELD), MELD-Na, and etiology of liver disease.

RESULTS

Among 406 ESLD patients analyzed, 207 (51.0%) had QT prolongation. The only clinical variable associated with QT prolongation was male gender (OR = 3.04, 95%CI: 2.01-4.60, P < 0.001). During the study period, 187 patients (46.1%) died. QT prolongation was a significant independent predictor of mortality (OR = 1.69, 95%CI: 1.03-2.77, P = 0.039). In addition, mortality was also associated with viral etiology of ESLD, elevated MELD score and its components (P < 0.05 for all). No significant reversibility in the QT interval was seen after liver transplantation.

CONCLUSION

QT prolongation was commonly encountered in an ESLD population, especially in males, and served as a strong independent marker for increased mortality in ESLD patients.

The role of autonomic dysfunction in cirrhotic patients before and after liver transplantation. Review of the literature

In patients affected by hepatic cirrhosis, autonomic dysfunction is a common finding; usually it is asymptomatic but it may correlate with increased mortality and morbidity before, during and after liver transplant, due to hemodynamic instability in the course of stressful events like sepsis, gastrointestinal bleeding and reperfusion after transplantation surgery. Hyperdynamic circulation and hepatic dysfunction seem to play a role in the pathogenesis of autonomic dysfunction, even if pathophysiological mechanisms are not completely known. We present a revision of previous literature about prevalence, pathophysiological mechanisms, clinical features, and mortality and morbidity of autonomic dysfunction secondary to hepatic cirrhosis.

Impact of cardiac dysfunction on health-related quality of life in cirrhotic liver transplant candidates

OBJECTIVE

Cardiac dysfunction, in particular left ventricular diastolic dysfunction, is common in cirrhosis. We aimed to investigate the impact of cardiac dysfunction on health-related quality of life (QoL) in liver cirrhosis.

MATERIALS AND METHODS

A total of 88 cirrhotic liver transplant candidates with an available echocardiogram and ECG completed the Short form-36 (SF-36) and Fatigue Impact Scale. In a subgroup of 61 patients, levels of cardiac biomarkers, in particular serum N-terminal pro-brain natriuretic peptide, adiponectin, and high-sensitive troponin T, were also measured.

RESULTS

Although left ventricular systolic diameter was related to a lower SF-36 physical component summary, neither left ventricular diastolic dysfunction nor any other echocardiographic feature was found to be associated with any other SF-36 or Fatigue Impact Scale domain (P>0.05 for all). On linear regression analysis after adjustment for confounders, a prolonged QTc interval was found to be related to a lower SF-36 mental component summary score (β=-9.7, P=0.009) and increased physical fatigue (β=10.5, P=0.004). Neither serum N-terminal pro-brain natriuretic peptide, high-sensitivity troponin T, nor adiponectin levels were found to be related to QoL (P>0.05 for all). Serum adiponectin levels did not differ among patients with versus those without echocardiographic cardiac alterations (P>0.05 for all).

CONCLUSION

A prolonged QTc interval, but not any echocardiographic abnormalities or cardiac biomarkers, seems to be predictive of QoL in cirrhosis.

Establishment and validation of ALPH-Q score to predict mortality risk in patients with acute-on-chronic hepatitis B liver failure: a prospective cohort study

Currently, there are no robust models for predicting the outcome of acute-on-chronic hepatitis B liver failure (ACHBLF). We aimed to establish and validate a new prognostic scoring system, named ALPH-Q, that integrates electrocardiography parameters that may be used to predict short-term mortality of patients with ACHBLF. Two hundred fourteen patients were included in this study. The APLH-Q score was constructed by Cox proportional hazard regression analysis and was validated in an independent patient cohort. The area under the receiver-operating characteristic curve was used to compare the performance of different models, including APLH-Q, Child-Pugh score (CPS), model of end-stage liver disease (MELD), and a previously reported logistic regression model (LRM). The APLH-Q score was constructed with 5 independent risk factors, including age (HR = 1.034, 95% CI: 1.007-1.061), liver cirrhosis (HR = 2.753, 95% CI: 1.366-5.548), prothrombin time (HR = 1.031, 95% CI: 1.002-1.062), hepatic encephalopathy (HR = 2.703, 95% CI: 1.630-4.480), and QTc (HR = 1.008, 95% CI: 1.001-1.016). The performance of the ALPH-Q score was significantly better than that of MELD and CPS in both the training (0.896 vs 0.712, 0.896 vs 0.738, respectively, both P < 0.05) and validation cohorts (0.837 vs 0.689, 0.837 vs 0.585, respectively, both P < 0.05). Compared with LRM, APLH-Q also showed a better performance (0.896 vs 0.825, 0.837 vs 0.818, respectively).We have developed a novel APLH-Q score with greater performance than CPS, MELD, and LRM for predicting short-term mortality of patients with ACHBLF.

Pre-transplant renal impairment predicts posttransplant cardiac events in patients with liver cirrhosis

BACKGROUND

Cardiovascular disease and renal impairment are common in cirrhotic transplant candidates. We aimed to investigate potential association between pretransplant renal function impairment and cardiac events after liver transplantation.

METHODS

Adult cirrhotic patients undergoing first-time liver transplantation between 1999 and 2007 in a single institution with available glomerular filtration rate (GFR), assessed by Cr-EDTA clearance at pre-transplant evaluation, were retrospectively enrolled (n=202). Impaired renal function was defined as GFR less than 60 mL/min/1.73 sqm. Pretransplant QT-time corrected by heart rate (QTc) and left-ventricular dysfunction was also registered. Mortality and cardiac events were analyzed, until death or last follow-up (end 2009).

RESULTS

Renal impairment was present in 24% (48/202). Cardiac events occurred in 28% (56/202) after transplantation, mean follow-up time of 3.8 years (2.2). Events were more common in patients with renal impairment compared with those without (48% versus 21%, P<0.001). In Cox regression analysis, pretransplant renal impairment was found to be an independent predictor of posttransplant cardiac events (HR 2.19, 95% CI 1.25-3.85) and reduced cardiac event-free survival (HR 2.27, 95% CI 1.31-3.94). Prolonged QTc interval was an independent predictor of posttransplant cardiac events in the subgroup with pretransplant electrocardiogram and echocardiogram (n=166 and n=112, HR 4.75, 95% CI 2.07-10.9); however, left-ventricular diastolic dysfunction was not (P>0.05). A pretransplant score comprising renal impairment, prolonged QTc interval, and age older than 52 was developed for prediction of 3- and 12-month cardiac events (c-statistic 0.73 and 0.75, respectively).

CONCLUSIONS

Pretransplant renal impairment is a predictor of cardiac event after liver transplantation together with prolonged QTc interval.

QT interval prolongation in end-stage liver disease cannot be explained by nonhepatic factors

INTRODUCTION

QT interval prolongation in patients with end-stage liver disease (ESLD) is common. However, electrolyte abnormalities, renal insufficiency, treatment with QT-prolonging drugs, and other factors known to prolong QT interval independently of liver disease occur frequently in ESLD. Moreover, elevated heart rate may be present in ESLD and result in spurious QTc prolongation if the Bazett formula is used for rate correction. It thus remains unclear whether QT prolongation in ESLD is directly caused by liver failure, or indirectly by these confounding factors.

METHODS

Medical records of all patients (n = 437) who received orthotopic liver transplantation (OLTx) at our institution between 2008 and 2011 were reviewed. Data from 51 patients with available pre-OLTx dobutamine stress echo (DSE), post-OLTx ECG and without nonhepatic factors affecting QT interval duration were analyzed. For each patient, QT versus RR regression line was calculated from ECG tracings obtained during DSE. The QT interval on post-OLTx ECG was compared with the pre-OLTx QT predicted by the regression line for the same RR interval.

RESULTS

QT interval shortened significantly post-OLTx (from 394 ± 47 to 364 ± 45 ms at RR interval 750 ± 144 ms; P < 0.002) when compared using the regression method. Corrected QT intervals calculated by Bazett and Fridericia formulas also shortened. Patients with prolonged QT pre-OLTx had significantly higher INR and lower serum albumin.

CONCLUSION

ESLD impairs ventricular repolarization even in the absence of other known factors affecting repolarization. QT prolongation in ESLD is associated with impaired synthetic liver function.

Prevalence of pre-transplant electrocardiographic abnormalities and post-transplant cardiac events in patients with liver cirrhosis

Background

Although cardiovascular disease is thouht to be common in cirrhosis, there are no systematic investigations on the prevalence of electrocardiographic (ECG) abnormalities in these patients and data on the occurrence of post-transplant cardiac events in comparison with the general population are lacking. We aimed to study the prevalence and predictors of ECG abnormalities in patients with cirrhosis undergoing liver transplantation and to define the risk of cardiac events post-transplant compared to the general population.

Methods

Cirrhotic patients undergoing first-time liver transplantation between 1999–2007 were retrospectively enrolled. ECGs at pre-transplant evaluation were reviewed using the Minnesota classification and compared to healthy controls. Standardized incidence ratios for post-transplant cardiac events were calculated.

Results

234 patients with cirrhosis were included, 186 with an available ECG (36% with alcoholic and 24% with viral cirrhosis; mean follow-up 4 years). Cirrhotics had a prolonged QTc interval, a Q wave, abnormal QRS axis deviation, ST segment depression and a pathologic T wave more frequently compared to controls (p < 0.05 for all). Arterial hypertension, older age, cirrhosis severity and etiology were related to ECG abnormalities. Compared to the general Swedish population, patients were 14 times more likely to suffer a cardiac event post-transplant (p < 0.001). A prolonged QTc interval and Q wave were related to post-transplant cardiac events (p < 0.05 for all).

Conclusions

Pre-transplant ECG abnormalities are common in cirrhosis and are associated with cardiovascular risk factors and cirrhosis severity and etiology. Post-transplant cardiac events are more common than in the general population.

Diastolic and autonomic dysfunction in early cirrhosis: a dobutamine stress study

OBJECTIVE. Presence of cardiac dysfunction in patients with advanced cirrhosis is widely accepted, but data in early stages of cirrhosis are limited. Systolic and diastolic functions, dynamics of QT-interval, and pro-atrial natriuretic peptide (pro-ANP) are investigated in patients with early stage cirrhosis during maximal β-adrenergic drive. MATERIAL AND METHODS. Nineteen patients with Child A (n = 12) and Child B cirrhosis (n = 7) and seven matched controls were studied during cardiac stress induced by increasing dosages of dobutamine and atropine. RESULTS. Pharmacological responsiveness was similar in cirrhosis and controls and the heart rate (HR) increased by 66 ± 15 versus 67 ± 8 min(-1). HR-blood pressure product increased equally by 115% in both cirrhotic patients and controls. However, time to resume HR of 100 beats/min was significantly longer in cirrhosis, p < 0.01. The QTc interval increased after dobutamine infusion in cirrhosis (0.41 ± 0.02 vs. 0.43 ± 0.02 s, p = 0.001) but similar electrophysiological changes were seen in controls. Cardiac volumes increased with the severity of disease. The increased cardiac output was primarily attributed to increased stroke volume. The ejection fraction was similar in patients and controls. Peak filling rate was longer in cirrhosis compared to controls (1.8 ± 0.4 and 1.4 ± 0.2 end-diastolic volume/s, p < 0.01). Pro-ANP was higher in cirrhosis and increased during stress by 13% compared to 0% in controls, p < 0.01. CONCLUSIONS. These findings indicate that patients with early stage cirrhosis exhibit early diastolic and autonomic dysfunction as well as elevated pro-ANP. However, the cardiac chronotropic and inotropic responses to dobutamine stress were normal. The dynamics of ventricular repolarization appears normal in patients with early stage cirrhosis.

Impact of peri-transplant heart failure & left-ventricular diastolic dysfunction on outcomes following liver transplantation

BACKGROUND & AIMS

Assess the prevalence of peri-transplant heart failure and its potential relation to post-transplant morbidity and mortality.

METHODS

A retrospective study was performed on 234 consecutive cirrhotic patients undergoing liver transplantation in a single European center from 1999 to 2007 (mean age 52, 30% women, 36% with alcoholic liver disease, 24% with viral hepatitis, 18% cholestatic liver disease). Left ventricular diastolic dysfunction was defined as E/A ratio ≤ 1. We used the Boston classification for heart failure to assess the prevalence of peri-transplant heart failure. Patients were followed up for a mean of 4 years post-transplant (0.5-9 years).

RESULTS

Eighteen per cent of patients demonstrated diastolic dysfunction pretransplant. During the peri-transplantation period highly possible heart failure occurred in 27%. In logistic regression analysis, heart failure was independently related to lower mean arterial blood pressure (OR 0.94, 95% CR 0.91-0.98) and prolonged corrected QT time on ECG (OR 9.10, 95% CI 3.77-21.93) pretransplant. Peri-transplant mortality amounted to 5%, and was independently related to heart failure (OR 15.11, 95% CI 1.76-129.62) and the peri-transplant need of dialysis (OR 14.18, 95% CI 1.65-121.89). Heart failure was also associated with longer stay in the intensive care unit and peri-transplant cardiac events (P < 0.05). Long-term transplant-free mortality was independently related to diastolic dysfunction at baseline (Hazard ratio 4.82, 95% CI 1.78-13.06).

CONCLUSION

Heart failure occurs in approximately a quarter of patients with cirrhosis following liver transplantation and it is an independent predictor of mortality and morbidity.

QT interval prolongation in liver cirrhosis: innocent bystander or serious threat?

The ECG QT interval measures the length of ventricular systole. Its prolongation is essentially caused by a delayed repolarization phase, and is associated with an increased risk of ventricular arrhythmias and sudden death in several congenital and acquired conditions. Abnormalities in cardiac electrophysiology are well documented in patients with liver cirrhosis, and the prolonged QT interval has emerged as the electrophysiological hallmark of cirrhotic cardiomyopathy. This article will focus on: first, the epidemiology of QT interval prolongation in cirrhosis; second, the potential molecular mechanisms responsible for the pathogenesis of this electrophysiological abnormality and the putative role of circulating cardiotoxins; third, its prognostic meaning; and fourth, its clinical relevance, in terms of the association between the presence of a long QT interval and the occurrence of ventricular arrhythmias in cirrhotic patients treated with drugs known to increase the QT length or exposed to stressful conditions, such as liver transplantation, gastrointestinal bleeding and shock.

The heart in liver transplantation

The heart and liver are organs that are closely related in both health and disease. Patients who undergo liver transplantation may suffer from heart disease that is: (a) related to the original cause of the liver disease such as hemochromatosis, (b) related to the liver disease itself, or (c) related to other associated conditions. Furthermore, liver transplantation is one of the most cardiovascular stressful events that a patient with cirrhosis may undergo. After liver transplantation, the progression of pre-existing or the development of new-onset cardiac disease may occur. This article reviews the relationship between the heart and liver transplantation in the pre-transplant, intra-operative, and post-transplant periods.

Alterations in corrected QT interval following liver transplant in patients with end-stage liver disease

BACKGROUND

Studies have demonstrated that patients with end-stage liver disease (ESLD) often have a prolonged corrected QT interval (QTc) with variable changes in the QTc post-transplant. We sought to characterize the prevalence and degree of QTc prolongation in ESLD patients, identify risk factors for QTc prolongation, and assess changes in QTc following transplant.

HYPOTHESIS

QTc interval is prolonged in ESLD patients pre-transplant due to a variety of risk factors and shortens following liver transplantation.

METHODS

We conducted a retrospective, multicenter study utilizing 2 large liver-transplant databases. QTc intervals were calculated utilizing Bazett's formula. The cutoff used for prolonged QTc was 440 milliseconds for men and 460 milliseconds for women.

RESULTS

There were 269 patients (169 men, 100 women) included in the final analysis. The mean pre-transplant QTc was prolonged (449.0 ms), whereas the mean post-transplant QTc shortened and was within normal limits (416.7 ms) (P < 0.0001). QTc shortened after transplant in 87% of patients. QTc normalized in 70% of patients. Age and Model for End-Stage Liver Disease (MELD) score were not predictive of prolonged QTc at baseline.

CONCLUSIONS

ESLD patients often have a prolonged QTc, which frequently shortens or normalizes after transplant. Screening for prolonged QTc is warranted if medications known to prolong the QTc interval are used in ESLD patients pre-transplant. MELD score, age, and sex were not predictive of prolonged QTc at baseline.

Cirrhotic cardiomyopathy

Increased cardiac output was first described in patients with cirrhosis more than fifty years ago. Later, various observations have indicated the presence of a latent cardiac dysfunction, which includes a combination of reduced cardiac contractility with systolic and diastolic dysfunction and electrophysiological abnormalities. This syndrome is termed cirrhotic cardiomyopathy. Results of experimental studies indicate the involvement of several mechanisms in the pathophysiology, such as reduced beta-adrenergic receptor signal transduction, altered transmembrane currents and electromechanical coupling, nitric oxide overproduction, and cannabinoid receptor activation. Systolic incompetence in patients can be revealed by pharmacological or physical strain and during stressful procedures, such as transjugular intrahepatic portosystemic shunt insertion and liver transplantation. Systolic dysfunction has recently been implicated in development of renal failure in advanced disease. Diastolic dysfunction reflects delayed left ventricular filling and is partly attributed to ventricular hypertrophy, subendocardial oedema, and altered collagen structure. The QT interval is prolonged in about half of the cirrhotic patients and it may be normalised by beta-blockers. No specific therapy for cirrhotic cardiomyopathy can be recommended, but treatment should be supportive and directed against the cardiac dysfunction. Future research should better describe the prevalence, impact on morbidity and survival, and look for potential treatments.

Absence of effect of telbivudine on cardiac repolarization: results of a thorough QT/QTc study in healthy participants

The effect of telbivudine on cardiac repolarization was evaluated in healthy participants at clinical and supratherapeutic doses. Sixty-two participants were enrolled, stratified by sex, and randomized according to a crossover design among 4 treatment sequences: placebo, a single moxifloxacin 400-mg dose as positive calibrator, and telbivudine 600 and 1800 mg/d for 7 days. Intensive time-matched electrocardiogram measurements and pharmacokinetic sampling were performed at baseline and on day 7 over 24 hours. For telbivudine and moxifloxacin, time-matched, placebo-adjusted change from baseline in QT was calculated and corrected using Fridericia's formula (QTcF). While moxifloxacin produced the expected significant changes in QTcF, none of the changes in QTcF for either doses of telbivudine exceeded 5 ms, and none of the associated upper 1-sided 95% confidence intervals (CI) exceeded the limit of 10 ms. There was no increase in QTcF with increasing plasma telbivudine. The supratherapeutic dose of telbivudine was well tolerated with a safety profile similar to the clinical dose despite a 3-fold increase in plasma exposure. This study therefore met the criteria for a negative thorough QT study. Telbivudine had no adverse effect on cardiac repolarization in healthy participants, even at supratherapeutic exposure, suggesting a broad safety margin.

Impact of liver transplantation on rate-corrected QT interval and myocardial function in children with chronic liver disease*

Prolonged QTc interval (>440 ms) is a common abnormality in adult patients with CLD and has been reported to predict patient survival. In this study, 88 children who underwent evaluation for LT, including a 12-lead electrocardiogram and echocardiogram included to determine the frequency of QTc prolongation and related factors in children with CLD and the effect of LT on these factors. Sixty-nine healthy, age- and sex-matched children served as controls. QTc interval was prolonged in 40 CLD patients (45.4%). It was found to be related to PELD score and presence of portal hypertension. Mean QTc was higher in patients who died prior to LT than in the survivors without LT. Mortality risk was increased 3.66-fold in patients with prolonged QTc (p = 0.001, 95% CI: 2-7.2). Cox regression analysis showed that only PELD score was an independent predictor of survival (p = 0.001, beta = -0.41, 95% CI: 5.58-1.82). Five of 48 transplanted children died within three months post-transplant; QTc was not related to post-transplant survival (p = 0.27). QTc normalized in 63.8% patients after LT. After LT, LAD, LVEF, and LVPWT decreased. In conclusion, QTc prolongation is common in children with CLD and associated with high mortality. It may be useful for assessment of the severity of CLD and for the timing for transplantation.

The heart and the liver

Cardiac failure affects the liver and liver dysfunction affects the heart. Chronic and acute heart failure can lead to cardiac cirrhosis and cardiogenic ischemic hepatitis. These conditions may impair liver function and treatment should be directed towards the primary heart disease and seek to secure perfusion of vital organs. In patients with advanced cirrhosis, physical and/or pharmacological stress may reveal a reduced cardiac performance with systolic and diastolic dysfunction and electrophysical abnormalities, termed cirrhotic cardiomyopathy. Pathophysiological mechanisms include reduced beta-adrenergic receptor signal transduction and defective cardiac electromechanical coupling. However, the QT interval is prolonged in approximately half of patients with cirrhosis and it may be improved by beta-blockers. No specific therapy can be recommended but it should be supportive and directed against the heart failure. Transjugular intrahepatic portosystemic shunt insertion and liver transplantation affect cardiac function in portal hypertensive patients and cause stress to the cirrhotic heart, with a risk of perioperative heart failure. The risk and prevalence of coronary artery disease are increasing in cirrhotic patients and since perioperative mortality is high, careful evaluation of such patients with dobutamine stress echocardiography, coronary angiography and myocardial perfusion imaging is required prior to liver transplantation. Future research should focus on beneficial effects of treatment on cardiac function and mortality.

Autonomic neuropathy may be associated with delayed orocaecal transit time in patients with cirrhosis

Orocaecal transit (OCT) time is delayed in patients with cirrhosis, but the reasons for this remain unclear. We hypothesized that autonomic neuropathy (AN) may explain the delay in OCT.

METHODS

We determined OCT and autonomic function tests (AFT) in 48 patients (Child A-15, B-27, C-6) with cirrhosis of various aetiologies. AFT were categorized as normal, borderline, or abnormal. OCT was measured using the lactulose hydrogen (H2) breath test. OCT was defined as the time from baseline when there was a rise in H2 levels of >20 ppm over baseline or >10 ppm over baseline sustained over 2 consecutive time points.

RESULTS

Based on OCT, patients were separated into those with delayed OCT (>90 min, group I) and normal OCT (< or = 90 min, group II). Mean OCT time of patients in group I was 169.7+/-49.7 min vs. 84.4+/-12.1 min in group II. Baseline clinical characteristics of patients with and without AN, and those with normal and delayed OCT were similar. Presence of mild encephalopathy did not have an effect on OCT. AN was seen more frequently in group I than group II [16/32 (50%) vs. 3/16 (19%), p=0.03]. Logistic regression analysis showed that the presence of AN was the only independent variable associated with delayed OCT (OR 7.3, CI 1.3-39.4, p=0.02).

CONCLUSION

Our study showed that the presence of AN was associated with delayed OCT in patients with cirrhosis.

Effect of cirrhosis and liver transplantation on the gender difference in QT interval

The effect of gender on the QT interval in patients with cirrhosis before and after liver transplantation and the relation between the QT interval and changes in gender hormones after liver transplantation were assessed. The study showed that (1) physiologic gender difference in the QTc interval is abolished in cirrhosis, and it is not restored after liver transplantation, and (2) gender hormone concentrations had no effect on the QTc interval.

Effects of orthotopic liver transplantation on the corrected QT interval in patients with end-stage liver disease

Autonomic dysfunction is a recognized complication of end-stage liver disease (ESLD) associated with a poor prognosis. The corrected QT interval (QTc) on electrocardiogram is a marker of autonomic function. A few small studies have suggested that QTc may normalize with the return of liver function after orthotopic liver transplantation. We sought to determine how transplantation affects the QTc in patients with ESLD. The QTc from the pretransplantation evaluation of 46 patients with ESLD was compared with the QTc at 4-month posttransplantation follow-up. Other factors that can influence autonomic function also were evaluated. Most patients with ESLD (54%) showed a prolonged QTc (> or = 440 msec) at the pretransplantation evaluation (451 +/- 45 msec) that improved to within the normal range at posttransplantation follow-up (418 +/- 18 msec; P < 0.001). There was no relationship between QTc prolongation and Child-Turcotte-Pugh score, Model for End-Stage Liver Disease score, diabetes mellitus, age, or etiology of liver disease. Most patients with ESLD and a prolonged QTc will have a significant improvement in QTc after transplantation; however, 6.5% of patients in our study had a worsening of QTc after transplantation.

Acute non-selective beta-adrenergic blockade reduces prolonged frequency-adjusted Q-T interval (QTc) in patients with cirrhosis

BACKGROUND/AIMS

Earlier studies have shown a prolonged frequency-adjusted Q-T interval (QTc>0.440 s(1/2)) in a substantial fraction of patients with cirrhosis. The effect of beta-blockade on QTc is unknown, and its determination was the aim of the study.

METHODS

Seventeen patients with cirrhosis received 80 mg propranolol orally during a haemodynamic investigation with measurements at baseline and 90 min after propranolol ingestion.

RESULTS

Beta-blockade reduced cardiac output (-21%, P<0.001), heart rate (-20%, P<0.001), and the hepatic venous pressure gradient (HVPG, -17%, P<0.02). The mean QTc=0.460 s(1/2) was prolonged compared to 0.410 s(1/2) in age-matched controls (P<0.01). Whereas QTc decreased during beta-blockade in the cirrhotic patients (from 0.460 to 0.440 s(1/2), P<0.01), no effect was found in the subgroup with normal QTc (0.429 vs. 0.422 s(1/2), ns), and a reduction was seen in the patients with prolonged QTc (from 0.488 to 0.456 s(1/2), P<0.01). The percentage decrease in QTc was related to the reduction in HVPG (r=0.48, P=0.03) and cardiac output (r=0.56, P=0.02).

CONCLUSIONS

Acute non-selective beta-blockade reduces prolonged QTc towards normal values in patients with cirrhosis. The clinical significance of QTc reduction in arrhythmia is a topic for future research.

Prolongation of QTc interval: relationship with etiology and severity of liver disease, mortality and liver transplantation

BACKGROUND

A prolonged QTc interval has been reported in patients with liver disease. The objectives of our study were to determine whether a prolonged QTc interval was an independent predictor of mortality in patients with cirrhosis and to examine the effect of liver transplantation (LT) on QTc interval.

PATIENTS AND METHODS

We retrospectively studied two cohorts of patients - QTc interval was measured in 409 patients (pre-transplant group), and in 162 patients (transplant group) before and 6 months after LT. QT interval (mean) corrected (QTc) for ventricular rate was read from a 12-lead EKG. Patients with known cardiovascular disease or other risk factors that are known to cause a prolonged QTc interval were excluded.

RESULTS

Pre-transplant group. One hundred and sixty-two patients (40%) had a prolonged QTc interval (>440 ms). By binary logistic regression, age (P=0.005), alcoholic cirrhosis (P=0.007) and Child-Pugh scores (P=0.007) were independent predictors of prolonged QTc interval. Sixty-six patients died during a mean follow-up of 8.9 years. Although the Kaplan-Meier survival curve showed a lower survival in patients with a prolonged QTc interval (P=0.03 by log rank test), when survival was adjusted for the Child-Pugh score by Cox regression survival analysis, there were no survival differences in patients with and without prolonged QTc interval. Cox regression analysis showed that the Child-Pugh score (hazard ratio 1.5, CI 1.3-1.6, s<0.001) was the only independent predictor of survival. Transplant group. In this cohort, 91 patients (56%) had prolonged QTc (>440 ms) before LT. Mean QTc improved significantly after LT (429 +/- 29 ms vs. 450 +/- 39 ms P<0.002). Of the 91 patients with prolonged QTc, 50 (55%) normalized, three (3.3%) remained unchanged, 12 (13.3%) showed further prolongation, and 26 (28%) showed improvement but remained above normal limits. An additional nine patients who had normal QTc before LT developed prolonged QTc (>440 ms) after LT.

CONCLUSION

A prolonged QTc interval was common in patients with cirrhosis, but its presence had no independent effect on mortality. Prolonged QTc returns to normal values in about half of the patients after LT, suggesting that liver disease plays a role, but may not be the only factor in the pathogenesis of prolonged QTc.

QT interval in patients with non-cirrhotic portal hypertension and in cirrhotic patients treated with transjugular intrahepatic porto-systemic shunt

BACKGROUND/AIMS

A prolonged QT interval is frequent in chronic liver disease and its aetiology remains unsettled. The study's aim was to assess the role of portal hypertension in the pathogenesis of QT prolongation.

METHODS

We measured the QT interval in: (1) 10 patients with non-cirrhotic portal hypertension (NCPH) and preserved liver function; (2) 19 cirrhotic patients before, 1-3 and 6-9 months after transjugular intrahepatic porto-systemic shunt (TIPS) insertion.

RESULTS

Baseline corrected maximum QT interval (QTcmax) was prolonged (>440 ms) in eight NCPH and 16 cirrhotic patients, and its value did not differ between the two groups (453+/-8 vs. 465+/-6 ms, P=NS). No patients showed an abnormal baseline QT dispersion. In cirrhotic individuals, QTcmax further increased 1-3 months after TIPS (P=0.042), thereafter remaining steadily elevated. QT dispersion only increased at the second post-TIPS determination (P=0.030). Such changes occurred despite no deterioration of liver function, plasma electrolytes and haemoglobin.

CONCLUSIONS

QT interval is frequently prolonged in patient with both non-cirrhotic and cirrhotic portal hypertension and portal decompression by TIPS worsens this abnormality. These results suggest that the porto-systemic shunting is responsible for the altered ventricular repolarisation possibly through a dumping into the systemic circulation of splanchnic-derived cardioactive substances.