Interplay between Mitral Regurgitation and Transcatheter Aortic Valve Replacement with the CoreValve Revalving System: a Multicenter Registry

Selected in Circulation by F. D'Ascenzi



Francesco Bedogni, Azeem Latib, Nedy Brambilla, Federico De Marco, Jacopo Oreglia, Mauro Agnifili, Samuele Pizzocri, Stefania Lanotte, Roberto Latini, Anna Sonia Petronio, Marco De Carlo, Federica Ettori, Claudia Fiorina, Arnaldo Poli, Silvia Cirri, Stefano De Servi, Angelo Ramondo, Antonio Marzocchi, Giuseppe Tarantini, Rosario Fiorilli, Silvio Klugmann, Gian Paolo Ussia, Corrado Tamburino, Francesco Maisano, Antonio Colombo, Luca Testa




October 2013


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My Comment

Bedogni and colleagues sought to investigate in this multicenter registry the prognostic significance of different grades of mitral regurgitation (MR) on post-TAVI outcome, the impact of TAVI on MR severity, and the variables associated with post-TAVI improvement in MR. For these purposes, 670 patients with none/mild MR, 243 patients with moderate MR, and 94 patients with severe MR were analyzed. All patients underwent TAVI with CoreValve Revalving system.

Major findings

  • Patients with moderate or severe MR have a worse baseline clinical status and a significantly higher overall and cardiac mortality at 1-month and 1-year follow up as compared with patients with mild MR; moreover, there appears to be a step-wise increase in the risk of mortality across the three groups (none/mild, 10%; moderate. 12%; severe 17%).
  •  Severe pulmonary hypertension (HR 1.5, 1.1-2.2, p=0.03), atrial fibrillation (HR 1.6, 1.1-2.4, p=0.01), and MR more than mild (HR 2.9, 2.5-3.8, p=0.001) were independent predictors of overall 1-year mortality.
  • Among patients surviving at 1-year follow up, improved mitral function was observed in 47.0% of patients with severe MR at baseline, and 35.0% with moderate MR at baseline. A worsening was reported in 6.3%.
  • The absence of severe pulmonary hypertension (HR 2.9, -2.7-3.3, p=0.002), the absence of atrial fibrillation (HR 2.02, 1.88-2.9, p=0.003), and a functional etiology of MR (HR 2.6, 1.8-3.1, p=0.005), were independent predictors of an improvement in MR severity. Of note, the improvement in MR severity at 1-month follow up did not independently predict mortality; conversely, at 30-day follow up, the rate of hospitalisation for heart failure was significantly higher and the percentage of patients with NYHA class I-II was significantly lower among patients with severe MR at baseline.
  • No differences were observed in the low implantation rate between patients with and patients without a worsened MR.

My comments

The clinical impact and the evolution of MR after TAVI is still a matter of concern. Bedogni and colleagues provide stimulating data in this field, confirming that moderate or severe MR is not a contraindication to TAVI procedures and ruling out the hypothesis of mitral valve impairment by the nitinol frame of the CoreValve prosthesis. Collecting prognostic data, the authors provide crucial information particularly for patient’s selection. Indeed, while patients with mild MR and absence of severe pulmonary hypertension and atrial fibrillation have a high probability to have a favorable outcome, patients with severe MR, severe pulmonary hypertension, and atrial fibrillation have to be candidate with caution for TAVI because of a poor post-procedural prognosis.

Some Centers routinely treat patients with severe aortic stenosis and concomitant severe MR with a bridge aortic balloon valvuloplasty, revaluating the improvement of MR degree during the follow up and offering TAVI only to patients experiencing an improvement of MR. This strategy can be considered an option in such patients, also considering the difficulties to distinguish between functional vs. organic etiology of MR in octogenarian patients with diffuse calcifications of the cardiac valvular apparatus. However, in the era of evidence-based medicine, more data are needed: for this reason, the authors are to be congratulated for their contribution in this crucial dilemma and, given that MR in TAVI patients represents an everyday challenge for interventional cardiologists, randomized trials are required to determine which patient should truly benefit from TAVI.

1 comment

  • Didier TCHETCHE 21 Oct 2013

    This is indeed an important paper that will certainly change our criterias for TAVI patient selection. It is not always easy to identify which patient with MR is going to have a good outcome post TAVI and balloon valvuloplasty is often used as an intermediate step. We know have several prognostic factors that will help us in our selection process. Moreover it is quite reassuring to see that CoreValve implantation has no negative impact on the MR degree. This is probably due to a mature technique of implantation with a target landing zone regularly around 4 mm below the aortic annulus in these experienced italian teams At last, in some of those patients with important residual MR post TAVI, a staged and complementary MitraClip procedure could be considered for an overall outcome improvement.