In a retrospective cohort study published in the Journal of the American Heart Association, stress microvascular perfusion (MVP) assessments were found to be highly predictive of cardiovascular (CV) outcomes in liver transplantation (LT) candidates.1
Candidates for LT must undergo cardiac testing to ensure the presence of adequate cardiac reserve to withstand the substantial hemodynamic changes resulting from the procedure. In addition to these transplant-specific effects, cardiac changes associated with end-stage liver disease “can lead to abnormal cardiac contractility with electromechanical conduction abnormalities and diastolic and systolic dysfunction,” wrote the investigators in the new study. “Often the systolic dysfunction is masked as a result of decreased afterload from splanchnic vasodilatation but can be uncovered with exercise or pharmacological stress testing.”
As many as 7.5% of patients with advanced liver disease are estimated to have coronary artery disease (CAD),2,3 and even in the absence of obstructive coronary disease, a significant number of patients may have endothelial and microvascular function.4,5 However, there is currently no consensus on the optimal approach to evaluating CV risk in these individuals.
Previous findings demonstrate the utility of dobutamine stress perfusion echocardiography (DSPE) in detecting epicardial disease and identifying abnormal microvascular reserve.6 Athough other research indicated that abnormal MVP detected with DSPE may identify patients with advanced liver disease with elevated risk of cardiac complications, the study did not include patients with nonalcoholic fatty liver disease, and certain other factors were not examined.7
In the new study, researchers at the University of Nebraska Medical Center (UNMC) aimed to “evaluate the prognostic importance of DSPE in adult patients undergoing isolated LT for or predicting both cardiovascular and overall clinical outcomes…,” they stated. Using electronic health records and the LT database at UNMC, they analyzed data pertaining to 296 adult patients with LT (67% men; mean age at transplant: 59±6). The top causes of liver failure in the sample were hepatitis C (25%) and nonalcoholic fatty liver disease (13%). The main study outcome was post-LT cardiovascular death, nonfatal myocardial infarction, and/or sustained ventricular arrhythmias.
According to the results, 18 patients showed abnormal MVP during stress (6%), and the risk of a post-LT CV event and nonfatal myocardial infarction was 7 times higher in these patients, despite revascularization. Diastolic dysfunction was observed in 109 patients (grade 1 in 94 patients; grade 2 in 15 patients). Abnormal MVP was the only variable that independently predicted the primary outcome (P =.004; hazard ratio 7.7); no predictive effect was observed for left ventricular ejection fraction, diastolic function, or stress-induced wall motion abnormalities.
“Abnormal MVP during demand stress identified patients with significant epicardial CAD as well as coronary microvascular dysfunction without epicardial CAD,” the researchers summarized. “The assessment of MVP with DSPE appears to be a useful noninvasive technique to risk-stratify patients with end-stage liver disease undergoing LT in the current era.”
- Baibhav B, Mahabir CA, Xie F, Shostrom VK, McCashland TM, Porter TR. Predictive value of dobutamine stress perfusion echocardiography in contemporary end-stage liver disease. J Am Heart Assoc. 2017;6:e005102 . doi:10.1161/JAHA.116.005102
- Carey WD, Dumot JA, Pimentel RR, et al. The prevalence of coronary artery disease in liver transplant candidates over age 50. Transplantation. 1995; 59:859-864.
- Donovan CL, Marcovitz PA, Punch JD, et al. Two-dimensional and dobutamine stress echocardiography in the preoperative assessment of patients with end-stage liver disease prior to orthotopic liver transplantation. Transplantation. 1996;61:1180-1188.
- Ong P, Athanasiadis A, Borgulya G, Mahrholdt H, Kaski JC, Sechtem U. High prevalence of a pathological response to acetylcholine testing in patients with stable angina pectoris and unobstructed coronary arteries. The ACOVA Study (Abnormal COronary VAsomotion in patients with stable angina and unobstructed coronary arteries). J Am Coll Cardiol. 2012;59:655-662. doi:10.1016/j.jacc.2011.11.015
- Sara JD, Widmer RJ, Matsuzawa Y, Lennon RJ, Lerman LO, Lerman A. Prevalence of coronary microvascular dysfunction among patients with chest pain and nonobstructive coronary artery disease. JACC Cardiovasc Interv. 2015; 8:1445-1453. doi:10.1016/j.jcin.2015.06.017
- Xie F, Dodla S, O’Leary E, Porter TR. Detection of subendocardial ischemia in the left anterior descending coronary artery territory with real-time myocardial contrast echocardiography during dobutamine stress echocardiography. JACC Cardiovasc Imaging. 2008;1:271-278. doi:10.1016/j.jcmg.2008.02.004
- Tsutsui JM, Mukherjee S, Elhendy A, et al. Value of dobutamine stress myocardial contrast perfusion echocardiography in patients with advanced liver disease. Liver Transpl. 2006;12:592-599. doi:10.1002/lt.20651