Covert cognitive deficit before liver shunt placement predicts hepatic encephalopathy

Last Updated: 2016-03-23

By Joan Stephenson

NEW YORK (Reuters Health) - The presence of covert cognitive impairment in patients before they receive a transjugular intrahepatic portosystemic shunt (TIPS) can help identify those at risk for overt hepatic encephalopathy (HE) after shunt placement, researchers from Italy report.

Psychometric evaluation before a TIPS "is able to identify most of the patients who will develop HE after a TIPS and can be useful to select patients in order to have the lowest incidence of this important complication," the team writes in the American Journal of Gastroenterology, online March 1.

This is particularly the case for patients who receive a shunt because of refractory ascites, noted the researchers, from the Sapienza University of Rome.

About 30% to 55% of cirrhotic patients develop HE after they are treated with a TIPS, which is used in patients with complications of portal hypertension. Up to one in 10 TIPS patients may experience a severe, refractory form of HE that requires reducing the shunt diameter.

Previous studies had shown that the presence of subclinical cognitive impairment, or covert HE, is a strong predictor of overt encephalopathy after the procedure. Because selection of patients is currently the only way to try to reduce the incidence of post-TIPS HE, the researchers sought to determine whether detecting covert HE with a psychometric evaluation before TIPS can help identify patients at risk for developing the condition after shunt placement.

The study included 82 consecutive patients (mean age, 57.8; 70% male) who underwent the psychometric HE Score (PHES) battery of tests designed to diagnose the subtle cognitive deficits that characterize minimal HE in patients with cirrhosis. Patients underwent TIPS placement (37 for variceal bleeding and 45 for ascites) the following day.

The researchers estimated the cumulative incidence of the first episode of HE during the first six months of follow-up, taking into account the competing risks (death or liver transplantation) in the data.

A total of 35 (43%) patients developed at least one episode of overt HE within six months after TIPS, and HE persisted in three individuals after standard treatment until it was resolved by reducing the stent caliber, the researchers report.

About 77% of patients who developed HE after shunt placement had a PHES score indicating the presence of covert HE before the procedure. Compared with patients who did not have pre-TIPS covert HE, those who did were significantly more likely to develop overt encephalopathy within six months after TIPS placement (p=0.0003).

Patients who developed post-TIPS HE were also significantly older (62 vs. 55 years) and had significantly lower serum sodium levels (135 vs. 138 mEq/l) than those who did not.

In a multivariate model, covert HE, age, and Child-Pugh score (derived from parameters such as standard liver function measures, extent of ascites, and degree of HE) were independently associated with developing HE after shunt placement.

If the presence of only covert HE is considered (and not age or Child-Pugh score), the negative predictive value is 0.80 for all 82 patients and 0.88 for the 45 patients who received a shunt because of refractory ascites.

"This means that a patient with refractory ascites, without covert HE according to PHES before a TIPS, has almost 90% probability of being free of HE after a TIPS," the researchers write.

The new study "shows that covert HE predicts a lower threshold for developing overt HE after portacaval diversion by TIPS," Dr. Arun Sanyal, of Virginia Commonwealth University's School of Medicine, told Reuters Health by email. "No surprises there."

The work's main value is showing that testing for covert HE can identify those with a low risk of HE post-TIPS, said Dr. Sanyal, who was not involved with the study.

"While this study also allows one to identify those at risk of HE after TIPS, presumably for ascites, the good news is that HE can be largely managed effectively after it develops and only a minority of individuals need modification of the TIPS or even occlusion," he said.

First author Dr. Silvia Nardelli did not respond to requests for comment by press time.

The study had no commercial funding and the authors reported no disclosures.

SOURCE: http://bit.ly/1U8Zi1K

Am J Gastroenterol 2016.