EXPERT ANALYSIS FROM HEART VALVE SUMMIT 2016
CHICAGO (FRONTLINE MEDICAL NEWS) – Fixing the tricuspid valve should be part of left-sided heart operations in many cases of functional tricuspid regurgitation, but study data and international guidelines supporting the practice are too frequently ignored, said Steven Bolling, MD.
Speaking during Heart Valve Summit 2016, Dr. Bolling said that of the approximately four million U.S. individuals with mitral regurgitation, about 1.6 million, or 40%, have concomitant tricuspid regurgitation (TR). Yet, he said, only about 7,000 concomitant tricuspid valve (TV) repairs are performed in the 60,000 patients receiving mitral valve (MV) repair surgery annually, for a TV repair rate of less than 12%. “Tricuspid regurgitation is ignored,” said Dr. Bolling, a conference organizer and professor of surgery at the University of Michigan, Ann Arbor.
“When functional tricuspid regurgitation is fixed, the right ventricle gets better,” said Dr. Bolling, citing a study that showed favorable right ventricular remodeling after concomitant MV-TV repair.
A 2015 study followed 645 consecutive patients who underwent primary repair of degenerative mitral regurgitation. The patients who had concomitant TVR, he said, “had far less TR, better right ventricle function, and it’s safe. There was lower mortality and morbidity” ( J Am Coll Cardiol. 2015 May 12;65[18]:1931-8).
Citing a study of 5,589 patients undergoing surgery for mitral valve regurgitation only, 16% of these had severe – grade 3-4+ – TR preoperatively. However, at discharge, 62% of those had severe residual TR. Despite a “good” mitral result, said Dr. Bolling, multiple studies dating back to the 1980s have demonstrated that surgical repair of just the mitral valve still results in functional tricuspid regurgitation (FTR) rates of up to 67%. “There’s no guarantee of FTR ‘getting better,’” said Dr. Bolling.
The problem lies fundamentally in the annular dilation and change of shape of the tricuspid annulus, and so these issues must be addressed for a good functional result, he said. This dilation and distortion has been shown to occur in up to 75% of all cases of MR ( Circulation. 2006;114:1-492 ).
“Placing an ‘undersized’ tricuspid ring is actually restoring normal sizing to the annulus,” said Dr. Bolling. The normal tricuspid annular dimension is 2.8 cm, plus or minus 0.5 cm, he said. Patients fare better both in the immediate postoperative period and at follow-up with an “undersized” TV repair for FTR, he said.
And surgeons shouldn’t worry about stenosis with an “undersized” TV repair, he said. High school geometry shows that a 26-mm valve diameter yields an area of about 4 square cm, for a 2- to 3-mm gradient, said Dr. Bolling.
Detection of tricuspid regurgitation can itself be a tricky prospect, because tricuspid regurgitation is dynamic. “You should look for functional tricuspid regurgitation preoperatively,” said Dr. Bolling. “Under anesthesia, four-plus TR can become mild.” Accordingly, any significant intraoperative TR or a dilated annulus should be considered indications for tricuspid valve repair, he said.
Though adding TV repair to mitral surgery may add some complexity, it does not necessarily add risk, said Dr. Bolling, citing a study of 110 matched patients with FTR that found a trend toward lower 30-day mortality for combined repair, when compared to mitral repair only (2% versus 8.5%, P = .2).
However, the single-intervention group had a 40% rate of tricuspid progression compared to 5% when both valves were repaired, and the 5-year survival rate was higher for those who had the combined surgery (74% versus 45%; Ann Thorac Surg. 2009 Mar;87[3]:698-703 ).
According to American College of Cardiology/American Heart Association (ACC/AHA) guidelines for managing valvular heart disease , which were last updated in 2014, patients with severe TR who are undergoing left-sided valve surgery should have concomitant TV repair, a class I recommendation.
The European Society of Cardiology and the European Association for Cardio-Thoracic Surgery (ESC/EACTS) 2012 guidelines are in accord with the ACC/AHA for this population, also issuing a class I recommendation.
For patients with greater than mild TR who have tricuspid annular dilation or right-sided heart failure, TV repair is a class IIa recommendation, according to the ACC/AHA guidelines. For patients with FTR who also have either pulmonary hypertension or right ventricular dilation or dysfunction, TV repair is an ACC/AHA class IIb recommendation.
In the European guidelines, patients with moderate secondary TR with a tricuspid annulus over 40 mm in diameter who are undergoing left-sided valve surgery, or who have right ventricular dilation or dysfunction, should undergo TV repair. This is a class IIa recommendation in the ESC/EACTS schema.
Dr. Bolling reported financial relationships with the Sorin Group, Medtronic, and Edwards Lifesciences.
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