Jim Kling

November 05, 2012

LAS VEGAS, Nevada — Patients considered at low vascular risk who undergo orthotopic liver transplantation (OLT) were found to be at greater risk than expected, especially those with low to moderate multivessel disease and patients who had previously undergone coronary artery bypass graft (CABG) for severe disease. Patients in these categories had a 10-fold increase in risk for a posttransplant cardiac event compared with patients without coronary disease, according to a study presented here at the American College of Gastroenterology (ACG) 2012 Annual Scientific Meeting and Postgraduate Course.

Cardiovascular complications represent 70% of the adverse events that OLT patients experience within the first year of undergoing transplantation. There is uncertainty as to how much risk patients with mild to moderate coronary artery disease (CAD) have for developing post-OLT cardiac complications.

The researchers set out to determine whether the number of diseased vessels or the extent of coronary disease, as determined by angiography, was associated with risk for major adverse cardiac events (MACE — stable angina, ischemic stroke, myocardial infarction with ST elevation, non-ST elevation myocardial infarction, and cardiac-related death) following transplantation.

The study included 652 adult patients who underwent OLT at the researchers' institution between 1996 and 2008. Extent of coronary disease was ranked as mild (< 50%), moderate (50% - 70%), or severe (> 70%).

Forty-three patients (7%) had proven CAD. Twelve of those 43 patients (28%) experienced at least 1 post-OLT MACE (P = .004; median time to event, 20.1 months).

Out to 60 months' follow-up, patients with no evidence of CAD before OLT had a MACE incidence of 10.4% compared with 21.9% for those with single-vessel CAD and 31.6% for those with multivessel CAD (P = .008).

A similar trend was seen in the degree of CAD, inasmuch as the incidence of MACE in patients with mild CAD was 20.7% in the 60-month follow-up period compared with 31.2% in patients with moderate to severe CAD (P = .007).

Patients who had undergone coronary revascularization were also at heightened risk for MACE. Compared with patients with no history of CAD (MACE incidence, 10.4%), patients with CAD with no coronary revascularization had a 16.7% risk for MACE (hazard ratio [HR], 1.9; 95% confidence interval [CI], 0.74 - 4.7; P = .19) compared with 55.6% (HR, 7.6; 95% CI, 3.0 - 19.3; P < .001) for patients who underwent a coronary revascularization intervention.

Need to "Rethink Current Clinical Paradigm"

"We need to rethink our current clinical paradigm of deeming patients to be low vascular risk after coronary revascularization. On the contrary, coronary revascularization prior to liver transplantation carries an increased risk of morbidity and mortality," Mazen Albeldawi, MD, a fellow at the Digestive Disease Institute at the Cleveland Clinic, in Ohio, who presented the research, told Medscape Medical News.

"It's very clear that in patients with this comorbidity, doing a liver transplantation has higher risk. I think it's something we've known intuitively, and this shows us that it is indeed the case. A patient who is above 50 and has cardiovascular disease and cirrhosis is potentially going to have a much more difficult time overcoming the complications of a liver transplant. They need to be forewarned that they have a significantly increased risk of complications," Hugo Vargas, MD, professor of medicine at the Mayo Clinic in Phoenix/Scottsdale, Arizona, who moderated the session but was not involved in the study, told Medscape Medical News.

Dr. Albeldawi and Dr. Vargas have disclosed no relevant financial relationships.

American College of Gastroenterology (ACG) 2012 Annual Scientific Meeting and Postgraduate Course. Abstract 35. Presented October 23, 2012.