Author + information
- Carmelo Grasso, MD†∗ (, )
- Yohei Ohno, MD†,
- Guilherme F. Attizzani, MD†,
- Stefano Cannata, MD†,
- Sebastiano Immè, MD†,
- Marco Barbanti, MD†,
- Anna M. Pistritto, MD†,
- Margherita Ministeri, MD†,
- Anna Caggegi, MD†,
- Marta Chiarandà, MD†,
- Fabio Dipasqua, MD†,
- Giuseppe Ronsivalle, MD†,
- Sarah Mangiafico, MD†,
- Salvatore Scandura, MD†,
- Piera Capranzano, MD†,‡,
- Davide Capodanno, MD†,‡ and
- Corrado Tamburino, MD, PhD†,‡
- †Department of Cardiology, Ferrarotto Hospital, University of Catania, Catania, Italy
- ‡Excellence Through Newest Advances Foundation, Catania, Italy
- ↵∗Department of Cardiology, Ferrarotto Hospital, University of Catania, Via Citelli 29, Catania 95124, Italy, Tel. +39-95-7436201, Fax. +39-95-362429
To the Editor:
Surgical mitral valve repair (SMVR) is the preferred intervention for patients with either symptomatic severe mitral regurgitation (MR) or asymptomatic severe MR and left ventricular dysfunction (1). The rate of freedom from severe MR 10 years after SMVR, however, is reported to be 70% (2), leading to a considerable number of mitral valve reinterventions, which carry substantial risk, particularly in elderly patients and in those with significant comorbidities.
Percutaneous mitral valve repair (PMVR) with the MitraClip system (Abbott Laboratories, Abbott Park, Illinois) recently emerged as a promising therapeutic alternative to SMVR in patients who are at high risk or are unsuitable for conventional surgery (3). Because of its reduced invasiveness compared with conventional surgery, PMVR could as well function as a potential alternative to reoperation in patients with SMVR failure. Although the feasibility of transcatheter valve implantation after SMVR failure has already been reported (4), studies assessing the feasibility and efficacy of PMVR with the MitraClip system in this setting are very limited (5). We report, therefore, our initial experience with MitraClip implantation in patients with SMVR (i.e., annuloplasty) failure.
Between August 2008 and June 2013, a total of 154 consecutive patients with moderate to severe (grade 3+) or severe (grade 4+) MR determined to be at high surgical risk who underwent PMVR at our institution were prospectively included in our GRASP (Getting Reduction of Mitral Insufficiency by Percutaneous Clip Implantation) registry (6). The decision to proceed with PMVR was discussed by a dedicated heart team, including experienced clinical and interventional cardiologists, cardiovascular surgeons, and anesthesiologists. Qualifying inclusion and exclusion criteria for PMVR, as well as details of the procedure, were previously reported (3). Throughout the study period, PMVR was performed in 6 patients (3.9%) with surgical mitral valve annuloplasty failure. Baseline, procedural, and follow-up characteristics are listed in Table 1. The median interval between SMVR and PMVR was 8 years (range: 5 to 12 years). One case was performed, however, 7 days after SMVR as a “bailout” procedure for acute surgical failure. Device success, defined as residual MR grade ≤ 2+ after clip implantation, was achieved in all patients. Post-procedural MR grade, the mean pressure gradient of the mitral valve (4.9 ± 0.9 mm Hg), and mitral valve area (2.1 ± 0.4 cm2) were satisfactory. No cases of procedural death, stroke, myocardial infarction, or urgent cardiovascular surgery occurred. Patient # 6, in whom PMVR was performed in the acute phase (i.e., 7 days after SMVR), died because of multiple-organ failure during the hospital stay, thus imparting all-cause and cardiovascular mortality rates of 16.7% and 0%, respectively. Follow-up was available in all remaining 5 patients (median follow-up period 12 months; range: 3 to 31 months). All patients but one (Patient #3) experienced improvements in New York Heart Association (NYHA) functional class compared with baseline and maintenance or improvement of MR status compared with post-procedural at follow-up (Table 1).
When our findings are put into perspective with the overall population from the GRASP registry, the mean age and logistic European System for Cardiac Operative Risk Evaluation score were significantly higher in patients with versus without prior SMVR (74.8 ± 2.8 years vs. 71.6 ± 10.2 years, p = 0.041, and 19.6 ± 11.7 years vs. 10.4 ± 10.9 years, p = 0.046, respectively), whereas no significant differences were observed in terms of baseline NYHA functional class and left ventricular ejection fraction (37.0 ± 7.3% vs. 36.8 ± 13.2%, p = 0.942). All patients with prior SMVR underwent successful procedures with the implantation of only 1 clip, which was significantly lower compared with those without prior SMVR (p = 0.027). No significant differences were documented regarding device implantation and total fluoroscopy time, as well as length of hospital stay between the groups.
Patients with prior surgical mitral valve annuloplasty have reduced mitral valve areas due to the previously implanted annuloplasty ring; therefore, being able to effectively reduce MR by implanting only 1 clip (representative images shown in Fig. 1) per patient in our series was noteworthy, as we could show the effectiveness of the intervention while minimizing concerns regarding potential secondary increases in pressure gradients. Indeed, acceptable post-procedural transvalvular mean pressure gradients and mitral valve areas were demonstrated in all patients (Table 1). Furthermore, we were able to demonstrate the stability of MR reduction coupled with improvement in left ventricular ejection fraction and NYHA functional class in all but in 1 patient over time. Another important finding, despite our small number of patients, was the safety of PMVR in patients with SMVR failure; in fact, notwithstanding the high baseline patient risk profile, no procedure-related adverse events were documented.
We acknowledge some limitations of our pivotal study. First, the comparisons between patients with and without prior SMVR should be interpreted with caution, because they were not pre-defined in our initial protocol; nevertheless, they help in settling our patients’ high-risk clinical status while reassuring the feasibility and original signs of effectiveness of the intervention performed. Second, larger series and longer term follow-up are warranted to confirm our initial findings in this highly selected population. Finally, determining the most appropriate therapy (i.e., PMVR or surgical reoperation) for patients with SMVR failure warrants future investigation.
In conclusion, we were able to demonstrate in a preliminary experience the safety and efficacy of PMVR with the MitraClip therapy in patients with surgical mitral valve annuloplasty failure. The promising results demonstrated herewith, therefore, open a new avenue for further investigation of the role of MitraClip implantation in this complex clinical scenario.
Please note: Dr. Ohno is supported by a grant from Japan Heart Foundation. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Grasso and Ohno contributed equally to this work.
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