Originally published January 4, 2019 as an update to Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine, 11th edition
Debra L. Beck and Eugene Braunwald, MD
Increasing numbers of patients are presenting with bioprosthetic mitral valve degeneration. Transcatheter mitral valve replacement (TMVR) is an emerging treatment for patients with severe mitral valve disease at high risk for conventional mitral valve surgery. Yoon et al sought to evaluate the outcomes of TMVR in patients with degenerated bioprostheses (valve-in-valve [ViV]), failed annuloplasty rings (valve-in-ring [ViR]), and severe mitral annular calcification (valve-in-mitral annular calcification [ViMAC]).
Using data from the international, multicenter TMVR registry, procedural and clinical outcomes of ViV, ViR, and ViMAC were compared according to Mitral Valve Academic Research Consortium (MVARC) criteria. A total of 521 patients with mean Society of Thoracic Surgeons score of 9.0% underwent TMVR: 322 of them had ViV, 141 had ViR, and 58 had ViMAC. Trans-septal access was used in 39.5% and Sapien valves were used 90.0%.
Overall technical success was “excellent” at 87.1%. However, left ventricular outflow tract obstruction was seen in 39.7% of ViMAC procedures, compared with 5.0% for ViR and 2.2% for ViV (p<0.001), and second valve implantation was more frequent needed in ViR (12.1%) compared with ViMAC (5.2%) and ViV (2.5%; p<0.001), yielding technical success rates of 94.4% after ViV, compared with 80.9% after ViR and 62.1% after ViMAC (p<0.001).
Post-procedural mitral regurgitation ≥moderate was noted in 18.4% of the ViR group, compared to 13.8% and 5.6% of the ViMAC and ViV groups (p<0.001). Post-procedural left ventricular ejection fraction remained lowest in the ViR group compared to the other two groups.
All-cause mortality at 30 days was highest at 34.5% after ViMAC, compared with 9.9% after ViR and 6.2% after ViV (log-rank p<0.001). One-year mortality rates were 62.8%, 30.6%, and 14.0%, respectively (log-rank p<0.001). On multivariable analysis, patients with failed annuloplasty rings and severe MAC were at increased risk of mortality after TMVR (ViR vs. ViV, hazard ratio (HR), 1.99, p=0.003; ViMAC vs. ViV, HR 5.29, p<0.001).
The investigators concluded that TMVR provided “excellent outcomes” for patients with degenerated bioprostheses (ViV), but those with failed annuloplasty rings (ViR) and severe mitral annular calcification (ViMAC) were more likely to experience procedural complications and were at increased mortality after the procedure. “As the present large study is consistent with recent reports with comparable early- and mid-term mortality, TMVR is an attractive option for patients with degenerated bioprosthetic mitral valves,” wrote the authors, but “poses unique and serious procedural challenges for those with failed annuloplasty repair and severe MAC.”
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