Intrepid Transseptal TMVR: No Mitral Regurgitation at 30 days

By Wally A. Omar, MD on

Key Points

  • Many patients with severe mitral valve regurgitation are not candidates for surgical valve replacement or transcatheter edge to edge repair due to anatomical limitations.
  • Transcatheter mitral valve replacement is currently under investigation with mostly transapical devices, which could be of added risk to patients.
  • In an early feasibility study of 15 patients, the APOLLO transcatheter mitral valve, a trans-septal based transcatheter valve replacement, was shown to significantly decrease mitral regurgitation in all patients.
  • At 30 day follow up there were no patient deaths. Major vascular access complications were seen in 40% of patients, which is an area that investigators hope to improve upon in the near future.

Transcatheter edge to edge repair (TEER) is currently approved for the treatment of mitral regurgitation in high or prohibitive risk patients. Not all mitral anatomy is suitable to edge to edge repair, however. In patients with prohibitive or high surgical risk, percutaneous options remain limited. The Intrepid device (Medtronic) has been studied as part of the ongoing APOLLO clinical trial. The initial iterations of the device required transapical access, which many argue is a less safe mode of delivery. During a late breaking session of the 33rd annual Transcatheter Therapies Conference today, Dr. Firas Zahr reported the early outcomes for the Early Feasibility Study of the Intrepid TMVR Transeptal System, in which the Intrepid valve was placed via transfemoral approach.

Procedural Details
The Transeptal Intrepid system ranges in size from 25 to 43F. Femoral venous access is obtained via surgical cutdown and exposure of the vessel, after which sutures are placed. A transseptal puncture is created and dilated with a 14 mm balloon, after which the device is introduced into the left atrium. The valve is then deployed in the mitral annulus after confirmation of positioning by TEE and fluoroscopic guidance.  For the early feasibility data, 15 patients were enrolled and followed through thirty days.

Procedural Success and Safety Outcomes
15 patients were enrolled, mostly men with a mean age of 80. The mean STS score for mitral valve replacement was 4.7% and greater than two-thirds had NYHA class III symptoms or higher. More than half had a previous cardiac surgery with sternotomy.  The procedure was successful in 14 out of 15 patients. The remaining patient had atrial migration of the valve which required surgical exploration and removal. There were no deaths or strokes reported. There were 2 instances of new onset atrial fibrillation or flutter. There were, however, 7 major bleeding events, accounting for 47% of patients. Furthermore, major vascular access complications requiring intervention was evident in 40% of patients.

Efficacy Outcomes:
Echocardiographic data at 30 days showed significant decrease in mitral regurgitation in all patients. Baseline echocardiograms demonstrated moderate to severe or severe MR in all patients, while 30-day post-replacement echos showed no MR in all patients. Furthermore, there was no evidence of paravalvular leak, and only one instance of mild LVOT obstruction. There was dramatic reduction in NYHA Class at 30 days as well such that no patients reported Class IV symptoms and most patients fell under the Class II category.

Dr. Zahr’s presentation was met with praise from the post-discussion panel, who also raised concerns about the vascular access complications reported in the trial. Dr. Zahr agreed, stating, “we were humbled by the vascular complications as well. We were aggressive about anticoagulation in patients with atrial fibrillation. We are hoping that standardization of anticoagulation and a smaller sheath size would improve these outcomes in the near future.”


The results of the trial were simultaneously published in JACC: Cardiovascular Interventions

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