SAN FRANCISCO – Nonalcoholic steatohepatitis patients may need a more thorough cardiovascular workup before liver transplantation, according to a study presented at the annual meeting of the American Association for Liver Diseases.
Standard pretransplant cardiac screening results were similar for 115 nonalcoholic steatohepatitis (NASH) and 127 alcohol-induced cirrhosis patients. Most patients had received transthoracic echocardiograms, and many had had other tests, including dobutamine stress echocardiograms, cardiac catheterizations, and ECGs.
The Revised Cardiac Risk Index, a common heart screen for noncardiac surgeries that focuses mostly on ischemia, predicted cardiac events in 6.6% of both groups.
The rate of cardiac events was higher in the NASH group; 26% had significant cardiac events within a year of surgery, two-thirds of those within a month. Cardiac arrests and arrhythmias – some fatal – were the most common events in the NASH group. Meanwhile, about 8% of the alcoholic-cirrhosis patients had cardiac events during their first postop year.
The inaccuracy of the screening of NASH patients illustrates the need for better methods of identifying cardiac risks prior to liver transplants, said investigator Dr. Lisa VanWagner, a first-year fellow in gastroenterology and hepatology at Northwestern University, Chicago.
"Current algorithms are designed to predict MI and plaque rupture. We tend to overutilize dobutamine stress echoes and other noninvasive stress tests to look for ischemic heart disease," she said.
In addition to atherosclerosis, NASH patients may have low systemic resistance, chronotropic incompetence, and other problems that a too-narrow focus on ischemia might miss. The cardiac arrests and arrhythmias noted in the study may not have been "related to plaque rupture. We really need to better risk-stratify these patients," said Dr. VanWagner, who noted she hopes to develop a liver-transplant specific cardiac risk index.
Tricuspid regurgitation might have predictive value, she said, as well as pulmonary hypertension and prolonged QTc interval, although the latter two did not differ significantly between the two groups before transplant.
Indeed, there were just two statistical differences; left ventricular hypertrophy was slightly more common in alcoholic-cirrhosis patients (20% vs. 15%), and that group was more likely than the NASH group to have clean coronary arteries on left heart catheterization (20% vs. 14%).
The mean age in the NASH group was 58 years, and 45% of NASH patients were women. The mean age in the alcoholic-cirrhosis group was 53 years, and 18% of patients were women. Mean MELD (Model for End-Stage Liver Disease) scores were about 25 for members of both groups.
NASH patients were more likely to be obese, dyslipidemic, and hypertensive. But even after controlling for those factors, as well as for smoking and prior history of coronary artery disease, NASH patients were still more likely to have an adverse cardiovascular event within a year of transplant (odds ratio, 2.69; 95% confidence interval, 1.32-6.34).
Most patients in both groups were alive at 1 year, but only 4% were alive in the NASH group at 10 years, compared with 18% in the alcoholic-cirrhosis group.
Before surgery, about 50% of NASH patients were on a beta-blocker, and 10% on a statin, although more than half had statin indications.
Dr. VanWagner said she has no disclosures.