It may be worthwhile to find a noninvasive way to test for heart transplant rejection because the conventional biopsy method is associated with a higher risk of severe Tricuspid regurgitation, a researcher said here.

In a group of 107 heart transplant patients, each endomyocardial biopsy increased the risk of having severe Tricuspid regurgitation by 17.1%, reported Sami Hayek, MD, from Henry Ford Hospital in Detroit, and colleagues.

The odds ratio for the number of biopsies to be associated with severe Tricuspid regurgitation was 1.17 (95% CI 1.07 to 1.27, P<0.0003), Hayek said at the annual meeting of the American Society of Echocardiography.

“This raises the question if other accurate bedside imaging techniques for endomyocardial biopsy guidance, use of better bioptomes, and search for other noninvasive accurate rejection markers are needed in this heart transplantation population,” researchers wrote.

In fact, cardiologists at Henry Ford Hospital have just begun to use real-time 3D echo to guide the biopsy procedure, Hayek told MedPage Today.

The conventional method is to use fluoroscopy to guide the biopsy procedure, but this does not allow detailed visualization of the tricuspid valve, he said.

“We know there are multiple reasons implicated in valve regurgitation, but one of them is the biopsy itself as previous studies have shown that valve tissue comes off during the biopsy,” Hayek said.

He noted that guidelines recommend screening for graft rejection every week during the first month postoperatively, and then every month thereafter for the first year. The gold standard test for rejection is the endomyocardial biopsy.

However, Tricuspid regurgitation is the most frequent valvular problem associated with transplantation, and it leads to a diminished quality of life and poorer survival outcomes.

To determine what impact the biopsies might have on Tricuspid regurgitation, the researchers examined the records of 107 heart transplant patients with data on the severity of Tricuspid regurgitation. The time span of transplants was between 1995 and 2008.

A total of 54 patients developed mild regurgitation, 28 moderate, and 25 severe.

A review of the echocardiograms performed prior to heart transplantation showed that right ventricular size was increased in 17% of those with severe Tricuspid regurgitation compared to none of the other patients.

In addition, 46% of those with severe regurgitation also had diminished right ventricular function compared with 29% and 14% of those with mild and moderate regurgitation, respectively.

Echocardiograms taken 3 months after heart transplantation also showed a decrease in right ventricular function, but only for 6% of those with severe regurgitation compared with none of the other patients, Hayek reported.

“We found that the more biopsies patients got, the more at risk they were for developing severe Tricuspid regurgitation,” Hayek said. “We suggest there should be noninvasive predictors of rejection than just exposing patients to multiple endomyocardial biopsies.”

Repairing or replacing the defective valve was found to reduce the risk of developing severe Tricuspid regurgitation by 95%, Hayek reported.

The study was limited by its retrospective nature and by the small number of records that contained the severity of regurgitation.

Hayek reported no conflicts of interest.

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By Chris Kaiser, Cardiology Editor, MedPage Today