Photo Credit: Hanna Sova

Significantly more patients with low cardiac reserve developed MACE within 30 days of liver transplant compared with patients with normal cardiac reserve.

“Major adverse cardiovascular events (MACE) are the leading cause of postoperative mortality following liver transplantation,” Benjamin Cailes, MBBS, BMedSci, and colleagues wrote. “Cirrhotic cardiomyopathy (CCM), a subclinical form of cardiac dysfunction, is suspected to contribute to these poor outcomes.”

Dr. Cailes and colleagues investigated the impact of impaired cardiac reserve on cardiac outcomes following liver transplantation. They published their results in Heart, Lung, and Circulation.

The study included patients undergoing liver transplantation workup with dobutamine stress echocardiogram. Cardiac output was measured at baseline and during low-dose dobutamine infusion at 10 μg/kg/min. For the study, the authors characterized impaired cardiac reserve as an inability to increase cardiac output by more than 25%. MACE was defined as myocardial infarction, ventricular arrhythmia, or heart failure exacerbation by 30 days.

Low Cardiac Reserve Tied to Higher MACE Risk

The study included 494 patients, 288 of whom proceeded to liver transplantation (58.3%). Researchers identified impaired cardiac reserve in 33.7% of those who underwent liver transplant. Patients with and without impaired cardiac reserve were similar in age, gender, and rates of hypertension or diabetes.

Results showed that a significantly greater proportion of patients with low cardiac reserve developed MACE within 30 days of liver transplantation compared with patients with normal cardiac reserve (26.7% vs 15.2%; P=0.018). The researchers noted this was driven in part by an increased rate of heart failure exacerbations among patients with impaired cardiac reserve (7.2% vs 1.6%; P=0.017). Low cardiac reserve remained the strongest predictor of MACE after adjusting for cardiovascular risk factors (HR, 2.0 [95% CI, 1.1-3.6]; P=0.026).

Using Cardiac Reserve in Risk Assessment

The findings add to previous research by Dr. Cailes and colleagues that identified impaired cardiac reserve as a surrogate marker of CCM. That study showed that low cardiac reserve was an independent predictor of waitlist mortality in liver transplant.

Both studies underscore the role of CCM in outcomes for patients undergoing liver transplant.

“These results endorse the integration of cardiac reserve assessment into CCM diagnostic criteria and its use in risk stratification of patients undergoing LT,” Dr. Cailes and colleagues wrote in the study on MACE after liver transplantation.