Older patients with atrial fibrillation are more likely to develop tricuspid regurgitation after isolated mitral valve repair for mitral regurgitation, according to a prospective study.

However, after a mean follow-up period of 9.1 years, only approximately 3.3 percent of patients had tricuspid regurgitation.

Lead researcher Tirone E. David, MD, of Toronto General Hospital, presented the results on May 16 during a plenary session at the American Association for Thoracic Surgery annual meeting in Baltimore.

The researchers evaluated 1,171 patients who underwent isolated mitral valve repair between 1985 and 2010. The mean age of the patients was 58.3 years old, and 60 percent of patients were men.

In addition, 44 percent had New York Heart Association functional Class III or IV heart failure, 20.2 percent had atrial fibrillation and 34 percent had an ejection fraction of greater than 60 percent. Further, at baseline, 17.1 percent of patients had coronary artery bypass, 11.2 percent had the maze procedure and 4.7 percent had tricuspid annuloplasty.

Before undergoing mitral valve repair, 45 percent of patients had mild tricuspid regurgitation, 8.4 percent had moderate tricuspid regurgitation and 3.3 percent had severe tricuspid regurgitation.

“Anybody with moderate or severe [tricuspid regurgitation] should have tricuspid annuloplasty,” David said.

During the follow-up period, 38 patients had recurrent mitral regurgitation or reoperation on the mitral valve, while 45 had recurrent or new tricuspid regurgitation. Of those patients, 14 had undergone previous surgery to repair the tricuspid valve.

“Although the number of patients who developed [tricuspid regurgitation] after [mitral valve] repair was small in our study, the effect of severe [tricuspid regurgitation] was devastating with a high mortality at one year after the diagnosis, which usually occurred during an episode of heart failure,” David said in a news release.

All of the patients who developed tricuspid regurgitation had a tricuspid annulus diameter of less than 40 mm. However, the researchers mentioned that developing tricuspid regurgitation had no effect on patients’ survival.

A multivariable analysis found that age by 5-year increments and preoperative atrial fibrillation were the two factors that were predictive of tricuspid regurgitation. The researchers said that preoperative atrial fibrillation was associated with a three-fold increased risk of tricuspid regurgitation.

At 15 years, 66 percent of patients were alive and free from adverse events, 20 percent had died and 14 percent had valve-related complications, including 7 percent with isolated tricuspid regurgitation, 4 percent with isolated mitral regurgitation, 2 percent with tricuspid regurgitation and mitral regurgitation and 1 percent with a reoperation without tricuspid or mitral regurgitation.

Of the patients without preoperative tricuspid regurgitation, 68 percent were alive and free from adverse events at 15 years, 20 percent were dead and 12 percent had valve-related complications, including 6 percent with isolated tricuspid regurgitation, 4 percent with isolated mitral regurgitation, 1 percent with tricuspid regurgitation and mitral regurgitation and 1 percent with a reoperation without tricuspid or mitral regurgitation.

Of the patients with preoperative tricuspid regurgitation or tricuspid annuloplasty, 45 percent were alive and free from adverse events at 15 years, 25 percent were dead and 30 percent had valve-related complications, including 15 percent with isolated tricuspid regurgitation, 6 percent with isolated mitral regurgitation and 9 percent with tricuspid regurgitation and mitral regurgitation.

“If you had [tricuspid regurgitation] before the operation, you are very likely to have more [tricuspid regurgitation] afterwards,” David said. “Patients with preoperative [tricuspid regurgitation] have lower long-term survival not because of [tricuspid regurgitation] but because of associated risk factors.”

David cited a few limitations of the study, including its retrospective design. He also mentioned tricuspid regurgitation was seldom addressed during the first half of the study and that tricuspid annulus diameter was not measured until 2005. They also did not include pulmonary artery pressure in their database.