Cardiac function in patients with early cirrhosis during maximal beta-adrenergic drive: a dobutamine stress study

Mechanisms of Acute Right Ventricular Injury in Cardiothoracic Surgical and Critical Care Settings: Part 2

The right ventricle (RV) is intricately linked in the clinical presentation of critical illness; however, the basis of this is not well-understood and has not been studied as extensively as the left ventricle. There has been an increased awareness of the need to understand how the RV is affected in different critical illness states. In addition, the increased use of point-of-care echocardiography in the critical care setting has allowed for earlier identification and monitoring of the RV in a patient who is critically ill. The first part of this review describes and characterizes the RV in different perioperative states. This second part of the review discusses and analyzes the complex pathophysiologic relationships between the RV and different critical care states. There is a lack of a universal RV injury definition because it represents a range of abnormal RV biomechanics and phenotypes. The term "RV injury" (RVI) has been used to describe a spectrum of presentations, which includes diastolic dysfunction (early injury), when the RV retains the ability to compensate, to RV failure (late or advanced injury). Understanding the mechanisms leading to functional 'uncoupling' between the RV and the pulmonary circulation may enable perioperative physicians, intensivists, and researchers to identify clinical phenotypes of RVI. This, consequently, may provide the opportunity to test RV-centric hypotheses and potentially individualize therapies.

Blunted cardiovascular effects of beta-blockers in patients with cirrhosis: Relation to severity?

Aims

Patients with cirrhosis and portal hypertension are at high risk of developing complications such as variceal hemorrhage, ascites, and cardiac dysfunction, the latter of which is known as cirrhotic cardiomyopathy. Since non-selective beta-blockers (NSBB) may aggravate hemodynamic complications we investigated the effect of real-time propranolol infusion on cardiac function in patients with varying degrees of cirrhosis.

Methods

Thirty-eight patients with Child-Pugh A (n = 17), B (n = 17) and C (n = 4) underwent liver vein catheterization and cardiac magnetic resonance imaging. We assessed the effect of real-time propranolol infusion on the hepatic venous pressure gradient, cardiac index, stroke volume, ejection fraction, heart rate, and contractility.

Results

Nineteen patients were classified as responders to beta-blocker therapy. In pooling Child-Pugh B and C patients, the reduction in cardiac index by beta-blockade was weaker than in Child-Pugh A patients (-8.5% vs. -20.5%, p = 0.043). The effect of NSBB on portal pressure was inversely correlated to changes in the left atrium where the left atrial volume changed by 4 mL±18 in responders compared to 15 mL±11 in non-responders (p = 0.03). Finally, the baseline ejection fraction correlated inversely with the reduction in portal pressure (r = -0.39, p = 0.02).

Conclusion

We found the effect of beta-blockade on cardiac index in patients with advanced cirrhosis to be less potent than in patients with early cirrhosis, indicating that underlying cirrhotic cardiomyopathy increases, and the cardiac compensatory reserve becomes more compromised, with disease progression. The differential effects of beta-blockade in the left atrium may be used to predict the effect of beta-blockers on portal pressure, but further studies are needed to investigate this possibility.

Management of Liver Decompensation in Advanced Liver Disease (Renal Impairment, Liver Failure, Adrenal Insufficiency, Cardiopulmonary Complications)

Systemic complications often occur in patients with advanced liver disease. In particular, the development of renal complications (acute kidney injury, hepatorenal syndrome), acute-on-chronic liver failure, cardiopulmonary diseases, or relative adrenal insufficiency can be serious in patients with advanced liver disease and may determine the patient’s quality of life and prognosis. Therefore, the early diagnosis of possible complications is the key to the prompt initiation of specific treatments that can improve quality of life and survival. For this purpose, networking with reference centers where multidisciplinary units are available is essential so that every patient is evaluated in clinical discussions involving specialists from different fields.

A Prospective Study of Prevalence and Predictors of Cirrhotic Cardiomyopathy and Its Role in Development of Hepatorenal Syndrome

BACKGROUND AND AIMS

Cirrhotic cardiomyopathy (CCM) is a term used to collectively describe abnormal structural and functional changes in heart of patients with cirrhosis. The present study was undertaken to find the prevalence of CCM in patients with liver cirrhosis and its predictors. We also followed these patients to evaluate the role of CCM in the development of hepatorenal syndrome (HRS).

MATERIALS & METHODS

This was a prospective study carried out in department of Gastroenterology, Sir Ganga Ram hospital, New Delhi. A total of 104 patients with liver cirrhosis were included. Liver cirrhosis was diagnosed on basis of clinical, biochemical, and imaging features. CCM was defined based on echocardiography. Dobutamine stress echocardiography and hepatic venous pressure gradient (HVPG) were performed in patients who gave consent. HRS was defined as per standard criteria. Patients with CCM were followed for development of HRS.

RESULTS

Fifty (48%) patients were diagnosed with CCM. All patients had diastolic dysfunction, and none had systolic dysfunction. Median age of patients with CCM was significantly higher (59 [31-78 y] vs. 52 [24-70 y], P < 0.05). Severity of liver disease (Child Turcotte Pugh score and model for end-stage liver disease score) and portal pressures (HVPG) did not differ in patients with or without CCM. Patients with CCM did not have increased incidence of HRS at the end of 6-month follow-up study.

CONCLUSION

The presence of CCM was not related with the severity of liver dysfunction or portal pressures. Age was a significant determinant of CCM. Diastolic cardiac dysfunction does not influence the occurrence of HRS.

Diagnosis and Prevalence of Cirrhotic Cardiomyopathy: A Systematic Review and Meta-analysis

The proposed diagnostic criteria for cirrhotic cardiomyopathy (CCM), defines it as documented echocardiographic findings of systolic or diastolic dysfunction (using conventional 2D echocardiogram), with or without electrophysiological abnormalities or elevated biomarkers in cirrhotic patients. In comparison to 2D echocardiogram, tissue Doppler imaging (TDI) has better sensitivity and specificity, when evaluating for cardiac dysfunction. This meta-analysis of 12 selected cohort studies attempted to estimate the pooled prevalence of CCM using either conventional echocardiography or TDI. Using the 2005 criteria, the pooled prevalence of CCM is 61% (P = 0.106). When TDI is used, the prevalence of CCM is at 45% (P = 0.088). Analyzing data of 615 cirrhotic patients, this study estimates the mean population-specific echocardiographic values of cirrhotic patients, including left ventricle ejection fraction (63.52%), deceleration time (229.04 ms), isovolumetric relaxation time (87.71 ms) and E/A ratio (1.04). In comparison to TDI, using standard 2D echocardiography leads to overdiagnosis of CCM.

Dobutamine reverses the cardio-suppressive effects of terlipressin without improving renal function in cirrhosis and ascites: a randomized controlled trial

Acute kidney injury and hepatorenal syndrome (HRS) are frequent complications in patients with cirrhosis and ascites. First-line treatment is terlipressin, which reverses HRS in ~40% of patients but also lowers cardiac output (CO). We aimed to investigate whether reversing the cardio-suppressive effect of terlipressin with the β-adrenoceptor agonist dobutamine would increase CO and thereby increase the glomerular filtration rate (GFR). We randomized 25 patients with cirrhosis, ascites, and impaired renal function (2:2:1): group A received terlipressin followed by the addition of dobutamine; group B received dobutamine and terlipressin as monotherapies; and group C received placebo. Renal and cardiac functions were assessed during 8 clearance periods of 30 min, and concentrations of vasoactive hormones were measured. Dobutamine as a monotherapy increased CO (1.03 L/min, P < 0.01) but had no significant effects on GFR. Renin (P < 0.05), angiotensin II (P < 0.005), and aldosterone (P < 0.05) increased after dobutamine infusion. Terlipressin as a monotherapy improved GFR (18.9 mL·min^-1·m^-2, P = 0.005) and mean arterial pressure (MAP) (14 mmHg, P = 0.001) but reduced CO (-0.92 L/min, P < 0.005) and renin (P < .005). A combined treatment of dobutamine and terlipressin had a positive effect on CO (1.19 L/min, P < 0.05) and increased renin (P < 0.005), angiotensin II (P < 0.005), and aldosterone (P < 0.05), but it had no significant effects on MAP or GFR. Dobutamine reversed the cardio-suppressive effect of terlipressin in cirrhosis, ascites, and impaired renal function. However, dobutamine reduced peripheral vascular resistance, activated renin-angiotensin-aldosterone system, and did not improve GFR compared with terlipressin as a monotherapy. Therefore, dobutamine cannot be recommended in cirrhosis and ascites.NEW & NOTEWORTHY This study shows that the cardio-suppressive effects of the vasopressin receptor agonist terlipressin can be reversed by dobutamine. This is a novel observation in patients with decompensated cirrhosis. Furthermore, we show that dobutamine reduced the peripheral vascular resistance and activated the renin-angiotensin system, whereas renal function was not further improved by terlipressin alone.

Cardiac Imaging in Liver Transplantation Candidates: Current Knowledge and Future Perspectives

Cardiovascular dysfunction in cirrhotic patients is a recognized clinical entity commonly referred to as cirrhotic cardiomyopathy. Systematic inflammation, autonomic dysfunction, and activation of vasodilatory factors lead to hyperdynamic circulation with high cardiac output and low peripheral vascular resistance. Counter acting mechanisms as well as direct effects on cardiac cells led to systolic or diastolic dysfunction and electromechanical abnormalities, which are usually masked at rest but exposed at stress situations. While cardiovascular complications and mortality are common in patients undergoing liver transplantation, they cannot be adequately predicted by conventional cardiac examination including transthoracic echocardiography. Newer echocardiography indices and other imaging modalities such as cardiac magnetic resonance have shown increased diagnostic accuracy with predictive implications in cardiovascular diseases. The scope of this review was to describe the role of cardiac imaging in the preoperative assessment of liver transplantation candidates with comprehensive analysis of the future perspectives anticipated by the use of newer echocardiography indices and cardiac magnetic resonance applications.

Low to Intermediate Dose Atropine Administration During Dobutamine Stress Echocardiography in the Pre-Liver Transplant Population

INTRODUCTION

Dobutamine stress echocardiography (DSE) is frequently used to screen for obstructive coronary artery disease in the pre-liver transplant evaluation. Although atropine is a commonly used adjunctive medication, no study has evaluated its side effect profile in patients with end-stage liver disease (ESLD).

RESEARCH QUESTION

What is the safety of atropine in candidates undergoing pre-liver transplant evaluation when atropine is used in stress testing?

DESIGN

This multicenter, prospective study enrolled patients over a 6-month period undergoing pre-liver transplant evaluation. Each patient completed a questionnaire assessing anticholinergic-related symptoms within 24 hours of testing and 48 hours following. Comparisons were made among patients receiving any atropine dose versus those who did not and among patients receiving at least 1 mg atropine and those receiving less/none.

RESULTS

Forty patients were evaluated, and 32 (80%) had adjunctive atropine administered. No differences in clinical characteristics were noted. In comparisons among patients receiving any dose of atropine with those who did not, questionnaire results indicated a higher rate of nausea prior to testing and higher overall symptom severity following testing in patients not receiving atropine. In comparisons among patients receiving less than 1 mg atropine with those receiving at least 1 mg atropine, no difference in pre- or posttesting questionnaire responses was present. No patient in the study required reversal agents or hospitalization within 7 days of testing.

CONCLUSIONS

Atropine, a hepatically metabolized medication, did not predispose patients with ESLD to an increased symptom burden, and clinical outcomes related to DSE were unaffected.

Pharmacodynamic analysis of target-controlled infusion of propofol in patients with hepatic insufficiency

The effect of liver dysfunction on target-controlled infusion (TCI) of propofol remains poorly documented. The pharmacodynamic performance of propofol TCI was evaluated in a cohort of Chinese patients with hepatic insufficiency. Fifty-three patients with hepatic insufficiency were enrolled in the current prospective, observational study. Anesthesia was induced with propofol via TCI to a plasma concentration of 3 µg/ml. Following loss of consciousness (LOC), fentanyl and cisatracurium were administered. Pharmacodynamic parameters were recorded during TCI, including time to LOC, bispectral index (BIS), heart rate (HR) and blood pressure. Patients were divided into two groups based on model of end stage liver disease (MELD) score: Those with a MELD score of ≤9 and those with a MELD score of ≥10. BIS, mean arterial pressure and HR were demonstrated to vary according to time, but were not affected by liver dysfunction. Hypotension was prominent in patients with a MELD score of ≥10 30 min after induction. The proportion of bradycardia and hypotension at the other time points was not significantly different between MELD scores of ≤9 and ≥10. Notably, no bradycardia was observed in MELD of ≥10. Thus, bradycardia and hypotension was observed in patients with hepatic insufficiency over time, although patients with different severities of hepatic insufficiency did not present with different depths of anesthesia. TCI of propofol to 3 µg/ml may be not suitable for patients with hepatic insufficiency, particularly those with severe liver dysfunction. Predictive concentrations (Cp) of TCI propofol requires further investigation and adjustment in patients with hepatic insufficiency (trial registration no. ChiCTR-OCH-12002255).

Impact of cytokine release on ventricular function after hepatic reperfusion: a prospective observational echocardiographic study with tissue Doppler imaging

BACKGROUND

Postreperfusion syndrome and haemodynamic instability are predictors for poor outcome after liver transplantation. Cytokine release has been claimed to be responsible for postreperfusion syndrome. However, the underlying pathophysiologic mechanism is not clarified. The aim of this prospective observational study was to correlate cardiac performance (measured by transoesophageal echocardiography (TEE), Doppler and Tissue Doppler Imaging (TDI)) to plasmatic cytokines: IL-6, IL-8, CXCL1, TGF-β and CD40L at 5 different time points during liver transplantation.

METHODS

Seventeen consecutive patients scheduled for orthotopic liver transplantation, age 18 to 75 years without contraindication for transoesophageal echocardiography were included. Patients were monitored with TEE and TDI. Systolic and diastolic cardiac function, MAP, MPAP, CVP, PCWP, CO and blood samples for cytokine assays were recorded or collected after induction, 15 min after vena cava inferior clamping, 2 to 5 min after reperfusion, 60 min after reperfusion and at the end of surgery.

RESULTS

Mean arterial pressure and catecholamine requirements remained unchanged, MPAP, CVP and CO increased, SVR decreased after unclamping. Postreperfusion syndrome did not develop. The haemodynamic parameters and the variations of TEE parameters were consistent with the volume load changes during clamping and declamping and did not reveal systolic or diastolic cardiac dysfunction. All cytokines, except TGF-β, increased.

CONCLUSION

These findings suggest, that significant cytokine release during liver transplantation is not necessarily coincident with haemodynamic instability and impaired cardiac function.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00547924.

Assessment of cardiovascular physiology using dobutamine stress cardiovascular magnetic resonance reveals impaired contractile reserve in patients with cirrhotic cardiomyopathy

BACKGROUND

Liver cirrhosis has been shown to affect cardiac performance. However cardiac dysfunction may only be revealed under stress conditions. The value of non-invasive stress tests in diagnosing cirrhotic cardiomyopathy is unclear. We sought to investigate the response to pharmacological stimulation with dobutamine in patients with cirrhosis using cardiovascular magnetic resonance.

METHODS

Thirty-six patients and eight controls were scanned using a 1.5 T scanner (Siemens Symphony TIM; Siemens, Erlangen, Germany). Conventional volumetric and feature tracking analysis using dedicated software (CMR42; Circle Cardiovascular Imaging Inc, Calgary, Canada and Diogenes MRI; Tomtec; Germany, respectively) were performed at rest and during low to intermediate dose dobutamine stress.

RESULTS

Whilst volumetry based parameters were similar between patients and controls at rest, patients had a smaller increase in cardiac output during stress (p = 0.015). Ejection fraction increase was impaired in patients during 10 μg/kg/min dobutamine as compared to controls (6.9 % vs. 16.5 %, p = 0.007), but not with 20 μg/kg/min (12.1 % vs. 17.6 %, p = 0.12). This was paralleled by an impaired improvement in circumferential strain with low dose (median increase of 14.4 % vs. 30.9 %, p = 0.03), but not with intermediate dose dobutamine (median increase of 29.4 % vs. 33.9 %, p = 0.54). There was an impaired longitudinal strain increase in patients as compared to controls during low (median increase of 6.6 % vs 28.6 %, p < 0.001) and intermediate dose dobutamine (median increase of 2.6%vs, 12.6 % p = 0.016). Radial strain response to dobutamine was similar in patients and controls (p > 0.05).

CONCLUSION

Cirrhotic cardiomyopathy is characterized by an impaired cardiac pharmacological response that can be detected with magnetic resonance myocardial stress testing. Deformation analysis parameters may be more sensitive in identifying abnormalities in inotropic response to stress than conventional methods.