Cardiac risk stratification in liver transplantation: results of a tiered assessment protocol based on traditional cardiovascular risk factors.

Abstract

Coronary artery disease (CAD) confers increased peri-operative risk in patients undergoing liver transplantation (LT). Although routine screening for CAD is recommended, there is limited data on the effectiveness of screening strategies. We evaluated the safety and efficacy of a 3-tiered cardiac risk-assessment protocol that stratifies patients based on age and traditional cardiac risk factors. A single-centre, prospective, observational study of consecutive adult patients undergoing LT assessment (2010 - 2017). Patients were stratified into low- (LR), intermediate- (IR) or high- (HR) risk cardiac groups and received standardised investigations with selective use of trans-thoracic echocardiography (TTE), dobutamine stress echocardiography (DSE), computed tomography coronary angiography (CTCA) and coronary angiography (CA). Primary outcomes were Cardiac Events (CE) and cardiovascular death up to 30-days post-LT. Overall, 569 patients were included. 76 patients were identified as LR, 256 IR and 237 HR. Cardiac risk factors included: diabetes (26%), smoking history (47%), hypertension (18%), hypercholesterolemia (7%), family (17%) or prior history of heart disease (6%) and obesity (28%). 42% patients had ≥2 risk factors. Overall compliance with the protocol was 90.3%. Abnormal findings on TTE, DSE and CTCA were documented in 3, 23 and 44 patients respectively and 12 patients were not listed for transplantation following cardiac assessment (1 LR, 2 IR and 9 HR). Moderate or severe CAD was identified in 25% of HR patients on CTCA following a normal DSE. CE were recorded in 7 patients (1.2%) with 2 cardiovascular deaths (0.4%). Cardiac risk stratification based on traditional cardiac risk factors with the selective use of DSE, CTCA and CA is a safe and feasible approach that results in a low peri-operative cardiac event rate.