New results from the TMVR (Transcatheter mitral valve replacement) Registry show that patients with a degenerated bioprosthesis who undergo transcatheter mitral valve implantation (TMVI) have relatively low rates of all-cause mortality (14%) at one year. However, suboptimal procedural outcomes are observed for patients who undergo TMVI for failed annuloplasty rings or for severe mitral annular calcification.
Sung-Han Yoon (Department of Interventional Cardiology, Cedars-Sinai Heart Institute, Los Angeles, USA) told delegates at the 2018 European Society of Cardiology (ESC) Congress (25–29 August, Munich, Germany) that TMVI—or “TMVR” as it is called in the USA—was “an emerging alternative treatment” for patients with mitral valve disease who were considered at high risk for conventional surgery. He added that as limited data exist regarding the procedural and clinical outcomes of TMVI, he, along with Raj Makkar (Department of Interventional Cardiology, Cedars-Sinai Heart Institute, Los Angeles, USA) and colleagues, initiated the TMVR Registry to evaluate the use of the procedure in patients with degenerated bioprosthetic valves, failed annuloplasty rings, or severe mitral annular calcification.
Data from the registry have already shown (as published in the Journal of the American College of Cardiology) that TMVI for both failed rings and for degenerated bioprostheses is associated with acceptable outcomes in high-risk patients. However, these findings also indicate that procedural complications and mid-term mortality is higher for TMVI in failed rings than TMVI for degenerated bioprostheses.
At the ESC Congress, Yoon presented outcomes for TMVI in severe mitral annular calcification as well as for failed surgical rings and degenerated bioprostheses. Of 521 patients overall, 322 underwent a valve-in-valve procedure, 141 underwent a valve-in-ring procedure, and 58 underwent TMVI for mitral annular calcification. Patients with mitral annular calcification had more frequent New York Heart Association (NYHA) Class IV heart failure symptoms (47% vs. 32% for valve-in-valve patients vs. 26% for valve-in-ring patients; p<0.02) whereas the valve-in-ring patients were more likely to have undergone coronary artery bypass grafting (CABG) and have had prior myocardial infarction. Most patients (90%) underwent TMVI with a Sapien valve (XT/S3, Edwards Lifesciences), with the remaining patients receiving a Lotus valve (Boston Scientific).
Technical success was highest in the valve-in-valve patients (94.4%) and lowest in the annular calcification patients (62.1%). Left ventricular outflow obstruction (LVOT) occurred significantly more frequently in the annular calcification patients—39.7% vs. 5% for valve-in-ring and 2.2% for valve-in-valve (p<0.001)—which Yoon noted resulted in a higher rate of alcohol septal ablation in this group (12.1% vs. 0.7% for valve-in-ring and 0.6% for valve-in-valve; p<0.01). Need for secondary mitral valve intervention was also highest in this group (22.4% vs. 17.7% for valve-in-ring vs. 10.9% for valve-in-valve; p=0.02), but need for a second valve was highest in patients undergoing valve-in-ring: 12.1% vs. 5.2% for annular calcification vs. 2.5% for valve-in-ring (p<0.001). Additionally, the valve-in-ring patients had the highest rates of moderate-to-severe mitral regurgitation (18.4% vs. 13.8% for annular calcification vs. 5.6% for valve-in-valve; p<0.001).
At 30 days, mortality was significantly increased in the mitral annular calcification group than in valve-in-ring and valve-in-valve groups: 34.5% vs. 9.9% vs. 6.2%, respectively (p<0.001). By one year, valve-in-valve patients had the lowest rate of all-cause mortality than either patients undergoing valve-in-ring or those with annular calcification (14% vs. 30.6% vs. 62.8%; log-rang p<0.001). All-cause mortality was still lowest in patients undergoing valve-in-valve in a landmark analysis of all-cause mortality between 30 days and one year: 8.4% vs. 23% for valve-in-ring and 43.2% for annular calcification (log-rank p<0.001).
Yoon reported that post procedural moderate or severe mitral regurgitation was associated with increased all-cause mortality in all groups (41.5% vs. 21.4% for mild mitral regurgitation; log-rank p=0.01). He added that compared with valve-in-valve procedures, valve-in-ring and mitral annular calcification procedures were both—in a multivariate model—independent predictors of all-cause mortality.
“There were excellent outcomes of TMVI for patients with degenerated mitral bioprosthetic valves despite high surgical risk, but there were suboptimal procedural outcomes for valve-in-ring and mitral annular calcification procedures,” Yoon told ESC delegates. He added that the higher rates of mid-term mortality for the valve-in-ring and annular calcification procedures were because of “adverse events and underlying mitral valve disease”. “Optimal patient selection and advanced device technology promise to improve the outcomes of TMVI,” he concluded.