Faulty Tricuspid Valve Linked to Less Success for Mitral Valve Therapy

PHOENIX -- Tricuspid regurgitation (TR) at baseline was linked to poorer outcomes after percutaneous mitral valve repair and didn't improve for most patients afterward, two registry studies showed.

The proportion alive and well based on quality-of-life scores at 1 year was significantly lower for patients with baseline severe TR compared with none, trace, or mild TR (adjusted OR 0.53, 95% CI 0.40-0.71).

The same stair step across mild to moderate to severe TR was seen for all-cause mortality at 1 year (adjusted HR 1.17, 95% CI 1.04-1.32 and aHR 1.49, 95% CI 1.29-1.72), with a nonsignificant trend in all-cause readmission as well, reported researchers led by Yasser Sammour, MD, MSc, of Houston Methodist, during the Society for Cardiovascular Angiography and Interventions (SCAI) meeting here.

And in another study of transcatheter mitral valve repair patients with concomitant severe TR, TR improved in only 42%, noted Craig Basman, MD, of Northwell Health and Lenox Hill Hospital in New York City, reporting the results at SCAI and online in JSCAI.

Impact of Baseline TR

Sammour and team's study included all 19,593 consecutive adults enrolled in the Society of Thoracic Surgeons/American College of Cardiology TVT Registry who had no prior mitral valve procedures and underwent isolated mitral valve transcatheter edge-to-edge repair (M-TEER) from January 2019 through June 2021. Baseline TR was none, trace, or mild for 52% of the patients, while 33% had moderate TR and 15% had severe TR.

Alive and well at 1 year was defined by a Kansas City Cardiomyopathy Questionnaire (KCCQ) score of at least 60 on the 100-point scale without a drop of 10 or more points compared with baseline.

Baseline KCCQ was poorer with higher grades of TR (45.4 with mild or less TR, 41.9 with moderate TR, and 38.1 with severe TR, P<0.0001). M-TEER procedural success showed the same pattern (76.3%, 73.2%, and 69.4%, P<0.0001).

"It's important to understand the impact of TR on those patient outcomes, especially in the emerging era of transcatheter interventions for tricuspid regurgitation," Sammour said. Such findings might help determine which patients would benefit the most from those therapies, he added.

Session moderator George Hanzel, MD, of Emory University in Atlanta, noted that "when we see people who have severe tricuspid and mitral regurgitation, I don't think we necessarily have to exclude them from treatment, but I think that we have to look at what the next treatment options are for the tricuspid valve."

"We know these patients ultimately do poorly," he continued. "I'm not sure if a tricuspid clip is the best way to treat them, but potentially, would they be good candidates for clinical trials to help hopefully improve their clinical status and hopefully long-term outcomes?"

Predictors of Success

Basman's study included the 107 patients with severe regurgitation of the the tricuspid and mitral valves among the 479 who underwent M-TEER with the MitraClip as recorded in the Northwell TEER registry, a "prospectively maintained mandatory database" of four high-volume valve centers in a single health system.

Of these patients, 84% had mitral regurgitation (MR) drop to moderate (grade 2+) or less, and 42% dropped at least one TR grade to moderate (2+) or less TR at 1 month.

In the unadjusted analysis, predictors of severe residual TR were right atrial area and lack of success in reducing MR. On the multivariate logistic regression model, the only predictor of a reduction in TR was MR reduction of 3+ with MitraClip.

"Other clinical and echocardiographic variables (including pulmonary hypertension, right ventricular function, tricuspid annular dilation, atrial fibrillation, and presence of a cardiac implantable electrical device) were not associated with residual TR," Basman and team noted. "Inability to predict TR reduction after M-TEER highlights the importance of establishing transcatheter tricuspid valve therapies and should factor in heart-team discussions."

An accompanying editorial by Vikrant Jagadeesan, MD, of West Virginia University School of Medicine in Morgantown, and John Blair, MD, of the University of Chicago Pritzker School of Medicine, pointed out that this study was the "largest analysis to date on significant predictors of severe TR after m-TEER," but the many limitations of the study hurt its ability to be practice-changing.

Along with the small sample size in a single hospital system, "the number of operators and their experience is not known, which may affect procedural success and outcomes," they added.

In addition, all baseline covariates were determined by transthoracic rather than transesophageal echocardiography, which left out a number of potential important analyzable predictors; for example, baseline tricuspid coaptation gap, which could be "very relevant" given that more than 90% of the TR pathology was functional. Moreover, degree of left ventricular systolic or right ventricular dysfunction were not quantified and procedural variables -- such as average number of clips per case or mitral mean gradients at the end of procedure or on follow-up -- were not described.

Furthermore, 12-month outcomes would have had more significance, the editorialists added.

"Future studies in larger cohorts using hemodynamic parameters and multimodality imaging will help elucidate in which patients residual TR after m-TEER is a bystander responsive to reduction in PA [pulmonary arterial] pressure or an accomplice to severe MR that will continue to portend a poor prognosis even after successful m-TEER," they concluded.