INTRODUCTION
In ESLD, cardiovascular events are one of the major cause of mortality. In order to avoid that, we should identify the patient with the highest risk and optimize them before surgery.
PREANAESTHETIC EVALUATION
In ESLD patient CVS involvement varies from subtle ECG to heart failure. There is a wide spectrum of cardiovascular involvement in ESLD which includes prolonged QTC on ECG, hypertension, IHD, cardiomyopathy, heart failure, hepato pulmonary syndrome, and porto pulmonary hypertension.
The risk factors for CAD in liver transplant candidate are
⦁ Age >50 years
⦁ Male
⦁ Hypertension
⦁ Dyslipidemia
⦁ DM
⦁ Obesity
Presences of 2 or more factors represent moderate to severe risk of CAD. History NASH independently increases the risk of CAD. Generally routine cardiovascular tests are performed are ECG and echo, further investigation are done as per needed.
CARDIAC EVALUATION
ECG – 12 lead is part of routine and prolonged QTc interval is common in CLD.
ECHO – In 5 to 10% of the population with CLD showed porto pulmonary hypertension. STRESS TEST- Inability of CLD patient to perform exercise necessitates to perform pharmacologic stress test. Dobutamine stress echocardiography is commonly used however it has variable sensitivity and limited ability to identify high risk cardiovascular events. CALCIUM SCORING- Coronary artery calcium using CT to identify early atherosclerosis.
Calcium scoring above 300 showed significant stenosis.
CARDIAC MAGNETIC RESONANCE ( CMR) – it has high diagnostic accuracy and is useful in assessing structural heart disease. In diseases like hemochromatosis CMR is useful to ascertain the severity in both heart and liver.
CARDIOPULMONARY EXERCISE TESTING – evaluates the cardiovascular and respiratory system during exercise.
6 MINUTES WALK TEST- patient with pretransplant 6MWT<250 m associated with increased morbidity.
CORONARY ANGIOGRAPHY- done in patients with CAD and positive stress tests. According to the American College of cardiology and the American heart association performing routine CAG in these patients carries more risk than benefit. CTCAG is emerging as a new modality in non-invasive assessment of CAD.
PROPOSED CARDIAC ALGORITHM FOR LIVER TRANSPLANT
CONCLUSION
Considering the major impact of cardiovascular events in liver transplant, effective cardiac risk stratification and optimization should be done in pre op period .Despite various recommendations for preoperative evaluation for cardiovascular disease in liver transplant candidates, a considerable controversy still exists.
Dr. Vaibhav V Savadi
Consultant
Department of Liver Transplant Anaesthesia and Critical Care