Relationship between QT interval prolongation and structural abnormalities in cirrhotic cardiomyopathy: A change in the current paradigm

Cirrhotic cardiomyopathy: Pathogenesis, clinical features, diagnosis, treatment and prognosis

Cardiac dysfunction among cirrhotic patients has long been recognized in the medical community. While it was originally believed to be a direct result of alcohol toxicity, in the last 30 years cirrhotic cardiomyopathy (CCM) has been described as a syndrome characterized by chronic cardiac dysfunction in cirrhotic patients in the absence of known cardiac disease, regardless of the etiology of cirrhosis. CCM occurs in about 60% of patients with cirrhosis and plays a critical role in disease progression and treatment outcomes. Due to its predominantly asymptomatic course, diagnosing CCM is challenging and requires a high index of suspicion and a multiparametric approach. Patients with CCM usually present with the following triad: impaired myocardial contractile response to exercise, inadequate ventricular relaxation, and electrophysiological abnormalities (notably prolonged QT interval). In recent years, research in this area has grown expeditiously and a new set of diagnostic criteria has been developed by the Cirrhotic Cardiomyopathy Consortium, to properly identify patients with CCM. Nevertheless, CCM is still largely unknown among clinicians, and a major part of its pathophysiology and treatment is yet to be understood. In the present work, we aim to compile and summarize the available data on the pathogenesis, clinical features, diagnosis, treatment, and prognosis of CCM.

mROS‑calcium feedback loop promotes lethal ventricular arrhythmias and sudden cardiac death in early myocardial ischemia

Lethal ventricular arrhythmia‑sudden cardiac death (LVA‑SCD) occurs frequently during the early stage of myocardial ischemia (MI). However, the mechanism underlying higher LVA‑SCD incidence is still poorly understood. The present study aimed to explore the role of mitochondrial reactive oxygen species (mROS) and Ca2+ crosstalk in promoting LVA‑SCD in early MI. RyR2 S2814A mice and their wild‑type littermates were used. MitoTEMPO was applied to scavenge mitochondrial ROS (mROS). Mice were subjected to severe MI and the occurrence of LVA‑SCD was evaluated. Levels of mitochondrial ROS and calcium (mitoCa2+), cytosolic ROS (cytoROS), and calcium (cytoCa2+), RyR2 Ser‑2814 phosphorylation, CaMKII Met‑282 oxidation, mitochondrial membrane potential (MMP), and glutathione/oxidized glutathione (GSH/GSSG) ratio in the myocardia were detected. Dynamic changes in mROS after hypoxia were investigated using H9c2 cells. Moreover, the myocardial phosphoproteome was analyzed to explore the related mechanisms facilitating mROS‑Ca2+ crosstalk and LVA‑SCD. There was a high incidence (~33.9%) of LVA‑SCD in early MI. Mice who underwent SCD displayed notably elevated levels of myocardial ROS and mROS, and the latter was validated in H9c2 cells. These mice also demonstrated overloads of cytoplasmic and mitochondrial Ca2+, decreased MMP and reduced GSH/GSSG ratio, upregulated RyR2‑S2814 phosphorylation and CaMKII‑M282 oxidation and transient hyperphosphorylation of mitochondrial proteomes in the myocardium. mROS‑specific scavenging by a mitochondria‑targeted antioxidant agent (MitoTEMPO) corrected these SCD‑induced alterations. S2814A mice with a genetically inactivated CaMKII phosphorylation site in RyR2 exhibited decreased overloads in cytoplasmic and mitochondrial Ca2+ and demonstrated similar effects as MitoTEMPO to correct SCD‑induced changes and prevent SCD post‑MI. The data confirmed crosstalk between mROS and Ca2+ in promoting LVA‑SCD. Therefore, we provided evidence that there is a higher incidence of LVA‑SCD in early MI, which may be attributed to a positive feedback loop between mROS and Ca2+ imbalance.

How non-alcoholic fatty liver disease and cirrhosis affect the heart

Liver diseases affect the heart and the vascular system. Cardiovascular complications appear to be a leading cause of death in patients with non-alcoholic fatty liver disease (NAFLD) and cirrhosis. The predominant histological changes in the liver range from steatosis to fibrosis to cirrhosis, which can each affect the cardiovascular system differently. Patients with cirrhotic cardiomyopathy (CCM) and NAFLD are at increased risk of impaired systolic and diastolic dysfunction and for suffering major cardiovascular events. However, the pathophysiological mechanisms behind these risks differ depending on the nature of the liver disease. Accurate assessment of symptoms by contemporary diagnostic modalities is essential for identifying patients at risk, for evaluating candidates for treatment, and prior to any invasive procedures. This review explores current perspectives within this field.

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.

Prevalence of cirrhotic cardiomyopathy according to different diagnostic criteria: alterations in ultrasonographic parameters of both left and right ventricles before and after stress

Background

We estimated the frequency of cirrhotic cardiomyopathy (CCM) using all of the proposed diagnostic criteria, to describe the whole spectrum of cardiac alterations, and to investigate the role of stress in unmasking latent cases of CCM.

Methods

Ninety consecutive patients were recruited. CCM was evaluated using the Montreal, the American Society of Echocardiography 2009 criteria, and the 2019 modified criteria of the CCM consortium. A dobutamine stress test was also performed.

Results

Left ventricular diastolic dysfunction (LVDD) was identified in 72 (80%), 36 (40%), and 10 (11.1%) patients based on the above criteria, respectively. None of the patients had right ventricular systolic dysfunction, either at rest or after stress. The dobutamine stress test revealed left systolic dysfunction in 4 (4.5%) patients. There was agreement among the 3 criteria that the presence of LVDD was not associated with the severity of liver disease, using Child-Pugh stage. However, patients with Child-B/C had longer QTc intervals (P=0.004), higher levels of brain natriuretic peptide (P=0.016), and greater echocardiographic E/e' ratio (P<0.001) and E/e'(s) (P=0.003), compared to Child-A patients, while a significant correlation was demonstrated between Child-Pugh score and E/e' (P<0.001), or E/e'(s) (P=0.002).

Conclusions

The prevalence of LVDD seems to be lower than previously considered. Right ventricular function seems to remain unimpaired. A dobutamine stress uncovered only a small percentage of patients with left systolic dysfunction. Nevertheless, the aggravation of several sonographic variables during stress, particularly in Child-B/C patients, potentially indicates a higher risk for clinical heart failure during stressful invasive interventions.

The predictive value of revised diastolic dysfunction in outcomes of liver transplantation: A propensity score matching analysis

Background

Diastolic dysfunction (DD), one of the earliest signs of cirrhotic cardiomyopathy (CCM), is included in the revised 2019 CCM criteria. Nonetheless, relevant research regarding the effects of revised DD on post-liver transplantation (LT) outcomes remains limited.

Methods

This retrospective study enrolled patients who underwent LT for decompensated cirrhosis, from January 2018 to March 2021. Patients were divided into DD and non-DD groups. Clinical data were collected. Patients were followed up with, for at least 1 year post-LT; cardiovascular adverse events (AEs) and survival status were recorded. Risk factors were identified using 1:2 propensity score matching (PSM), after adjusting for confounding factors. The caliper value was set to 0.02.

Results

Of 231 patients, 153 were diagnosed with DD (male, 81.8%; mean age, 51.5 ± 9.5 years). Nineteen patients with DD died within 1 year, post-LT. After PSM, 97 and 60 patients were diagnosed with and without DD, respectively. Patients with DD had longer intensive care unit (ICU) stays, higher perioperative cardiovascular AEs, and higher mortality rates than those without DD. In a multivariate analysis, interventricular septum (IVS), left atrial volume index (LAVI), and potassium levels were independent prognostic factors of perioperative cardiovascular AEs, while a decreased early diastolic mitral annular tissue velocity (e'), increased neutrophil-to-lymphocyte ratio (NLR) and tumor markers were predictors of mortality within 1 year post-LT after PSM (P < 0.05).

Conclusion

Cardiac DD may contribute to perioperative cardiovascular AEs and mortality post-LT. Clinicians should be aware of decompensated cirrhosis in patients with DD.