Amelioration of hypertrophic cardiomyopathy using nonsurgical septal ablation in a cirrhotic patient prior to liver transplantation

Preoperative echocardiography as a prognostic tool for liver transplant in patients with hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) presents with a hypertrophied left ventricle (LV). It is often associated with LV outflow tract obstruction (LVOTO) and a risk for sudden death. This study aimed to describe outcomes of patients with HCM who underwent liver transplant (LT).

METHODS

A retrospective review was conducted for patients diagnosed with HCM undergoing LT. Patient characteristics, preoperative echocardiography results, HCM risk of sudden cardiac death prediction model score, and 5-year mortality were examined. A univariable Cox proportional hazards model was used to evaluate the association between risk factors and 5-year mortality. All tests were two-sided with the alpha level set at .05.

RESULTS

Twenty-nine patients were included in the analysis. Six patients (21%) had a perioperative cardiopulmonary complication. The 5-year survival rate was 61% (95% CI, 45-82). The analyzed risk factors showed that 5-year post-LT survival was significantly predicted by maximal LV outflow tract gradient at rest > 60 mmHg (hazard ratio, 1.04 [95% CI, 1.01-1.06]).

CONCLUSIONS

Preoperative LV outflow tract resting gradient > 60 mmHg was associated with 5-year post-LT mortality. The results suggest the severity of LVOTO identified by echocardiography is a prognostic tool for patients with HCM after LT.

Cardiac diseases among liver transplant candidates

Improvements in early survival after liver transplant (LT) have allowed for the selection of LT candidates with multiple comorbidities. Cardiovascular disease is a major contributor to post-LT complications. We performed a literature search to identify the causes of cardiac disease in the LT population and to describe techniques for diagnosis and perioperative management. As no definite guidelines for preoperative assessment (except for pulmonary heart disease) are currently available, we recommend an algorithm for preoperative cardiac work-up.

Liver Transplantation in Patients With Cardiac Disease

Liver transplantation (LT) is a unique surgical procedure that has major hemodynamic and cardiovascular implications. Recently, there has been significant interest focused on cardiovascular issues that affect LT patients in all phases of the perioperative period. The preoperative cardiac evaluation is a major step in the selection of LT candidates. LT candidates are aging in concordance with the general population; cardiovascular disease and their risk factors are highly associated with older age. Underlying cardiovascular disease has the potential to affect outcomes in LT patients and has a major impact on candidate selection. The prolonged hemodynamic and metabolic instability during LT may contribute to adverse outcomes, especially in patients with underlying cardiovascular disease. Cardiovascular events are not unusual during LT; transplant anesthesiologists must be prepared for these events. Advanced cardiovascular monitoring techniques and treatment modalities are now routinely used during LT. Postoperative cardiovascular complications are common in both the early and late posttransplant periods. The impact of cardiac complications on posttransplant mortality is well recognized. Emerging knowledge regarding cardiovascular disease in LT patients and its impact on posttransplant outcomes will have an important role in guiding the future perioperative management of LT patients.

Perioperative Anesthetic Management of Patients Having Liver Transplantation for Uncommon Conditions

This review focuses on the perioperative anesthetic management of patients having liver transplantation (LT) performed for several uncommon indications or in combination with rare pathology. Conditions discussed in the article include Alagille syndrome, hypertrophic cardiomyopathy, Gilbert's syndrome, porphyria, Wilson's disease, and Budd-Chiari syndrome. In comparison to other indications, LT in these settings is infrequent because of the low incidence of these pathologies. Most of these conditions (with the exception of Gilbert syndrome) are associated with a high probability of significant perioperative complications and increased mortality and morbidity. Experience in management of these unusual conditions is only gained over time. Developing clinical pathways for patients with these conditions should result in outcomes similar to LT performed for more common indications.

Role of cardiovascular intervention as a bridge to liver transplantation

End stage liver disease (ESLD) is associated with many specific derangements in cardiovascular physiology, which influence perioperative outcomes and may profoundly influence diagnostic and management strategies in the preoperative period. This review focuses on evidence-based diagnosis and management of coronary, hemodynamic and pulmonary vascular disease in this population with an emphasis on specific strategies that may provide a bridge to transplantation. Specifically, we address the underlying prevalence of cardiovascular disease states in the ESLD population, and relevant diagnostic criteria thereof. We highlight traditional and non-traditional predictors of cardiovascular outcomes following liver transplant, as well as data to guide risk-factor based diagnostic strategies. We go on to discuss the alterations in cardiovascular physiology which influence positive- and negative-predictive values of standard noninvasive testing modalities in the ESLD population, and review the data regarding the safety and efficacy of invasive testing in the face of ESLD and its co-morbidities. Finally, based upon the totality of available data, we outline an evidence-based approach for the management of ischemia, heart failure and pulmonary vascular disease in this population. It is our hope that such evidence-driven strategies can be employed to more safely bridge appropriate candidates to liver transplant, and to improve their cardiovascular health and outcomes in the peri-operative period.

Cardiovascular risk assessment of the liver transplant candidate

Liver transplantation (LT) candidates today are increasingly older, have greater medical acuity, and have more cardiovascular comorbidities than ever before. Steadily rising model for end-stage liver disease (MELD) scores at the time of transplant, resulting from high organ demand, reflect the escalating risk profiles of LT candidates. In addition to advanced age and the presence of comorbidities, there are specific cardiovascular responses in cirrhosis that can be detrimental to the LT candidate. Patients with cirrhosis requiring LT usually demonstrate increased cardiac output and a compromised ventricular response to stress, a condition termed cirrhotic cardiomyopathy. These cardiac disturbances are likely mediated by decreased beta-agonist transduction, increased circulating inflammatory mediators with cardiodepressant properties, and repolarization changes. Low systemic vascular resistance and bradycardia are also commonly seen in cirrhosis and can be aggravated by beta-blocker use. These physiologic changes all contribute to the potential for cardiovascular complications, particularly with the altered hemodynamic stresses that LT patients face in the immediate post-operative period. Post-transplant reperfusion may result in cardiac death due to a multitude of causes, including arrhythmia, acute heart failure, and myocardial infarction. Recognizing the hemodynamic challenges encountered by LT patients in the perioperative period and how these responses can be exacerbated by underlying cardiac pathology is critical in developing recommendations for the pre-operative risk assessment and management of these patients. The following provides a review of the cardiovascular challenges in LT candidates, as well as evidence-based recommendations for their evaluation and management.

Cardiovascular dysfunction in patients with end-stage liver disease

Most patients with advanced liver disease have a normal or even supernormal ejection fraction judged by echocardiography. Thus, physicians previously assumed that cardiac function was normal in most patients with liver disease. However, further investigation has uncovered multiple problems in cardiac performance that place patients at risk of heart failure. Patients with liver disease have defects in both systolic and diastolic function that only become obvious with physiologic stress such as liver transplantation. In addition there are additional defects in the electromechanical coupling of the heart that can have significant clinical consequences. These collective pathologic changes are termed "cirrhotic cardiomyopathy" and occur to some degree in all patients with liver disease. This review will explore the pathophysiology of cardiovascular changes in patients with end-stage liver disease.

Cardiac evaluation of liver transplant candidates

Physicians previously thought that heart disease was rare in patients with end stage liver disease. However, recent evidence shows that the prevalence of ischemic heart disease and cardiomyopathy is increased in transplant candidates compared to most other surgical candidates. Investigators estimate that up to 26% of all liver transplant candidates have at least one critical coronary artery stenosis and that at least half of these patients will die perioperatively of cardiac complications. Cardiomyopathy also occurs in greater frequency. While all patients with advanced cardiac disease have defects in cardiac performance, a larger than expected number of patients have classical findings of dilated, restrictive and hypertrophic cardiomyopathy. This may explain why up to 56% of patients suffer from hypoxemia due to pulmonary edema following transplant surgery. There is considerable controversy on how to screen transplant candidates for the presence of heart disease. Questions focus upon, which patients should be screened and what tests should be used. This review examines screening strategies for transplant candidates and details the prognostic value of common tests used to identify ischemic heart disease. We also review the physiological consequences of cardiomyopathy in transplant candidates and explore the specific syndrome of “cirrhotic cardiomyopathy”.