Transcatheter Interventions of the “Forgotten Valve”

We have witnessed tremendous advances in the transcatheter therapies for various cardiac conditions in the past couple of decades! The “forgotten valve” usually refers to the tricuspid valve, due to the fact that most of the research in the literature is on the left-sided heart valves. In the past two decades, although there has been progressive interest in implementing transcatheter techniques to treat tricuspid valve pathologies, we are still in the early stages of this development.  So, I decided to write briefly about some of these transcatheter techniques, which will continue to improve in the future; as we get more experience with these tools and continue to implement the advances in related technologies.

Tricuspid Valve Interventions

There are two main types of transcatheter interventions of the tricuspid valve: repair and replacement.

  • Tricuspid Valve Repair

Tricuspid valve repair can involve the tricuspid annulus and/or leaflet coaptation. Leaflet coaptation is performed using the off-label use of MitraClip (Abbott) in the tricuspid valve (also known as TriClip), mainly because of the device availability and operator familiarity [1]. There are other repair systems to repair the tricuspid leaflet coaptation, including Forma (Figure 1) and Pascal systems from Edwards Lifesciences.  The Forma repair system consists of a spacer that occupies the regurgitant orifice and thus decrease regurgitation. The Pascal repair system consists of two paddles, clasps and a spacer, thus overcoming some of the limitations of Forma repair system regarding anchoring and dislodgement [1]. Other repair interventions involving the annulus are usually performed using sutures or an annuloplasty ring (Figure 2) [1].

Figure 1: Forma repair system (Edwards Lifesciences), which is a transcatheter approach to improve the leaflet coaptation of native tricuspid valve by occupying the regurgitant orifice area [2].

Figure 2: Cardioband (Edwards Lifesciences) is a transcatheter annuloplasty ring for the tricuspid valve [3].

  • Tricuspid Valve Replacement

The first transcatheter tricuspid valve replacement was performed by Kefer et al in 2014 using the balloon-expandable SAPIEN valve (Edwards Lifesciences). There are 6-7 types of dedicated transcatheter tricuspid valves that have been developed in the recent years; these include NaviGate (NaviGate Cardiac Structures, Lake Forest, California), Edwards Evoque, Medtronic Intrepid, Lux (Chinese designed and manufactured self-expanding prosthesis made from bovine pericardial tissue mounted on a nitinol stent frame), and Tricares (TRiCares GmbH, München, Germany) valve is a self-expanding prosthesis made from bovine pericardial tissue mounted on a nitinol stent frame. Figure 3 illustrates a NaviGate valve, which is the first tricuspid prosthetic valve implanted in humans in the United States, which was performed by Navia et al in November 2016 [1].  It is an example of a self-expanding dedicated tricuspid valve with 3 pericardial leaflets.

Figure 3: NaviGate valve, which is currently available for transcatheter tricuspid valve replacement [4].

  • Caval Stenting

In addition, stenting of the inferior and/or superior vena cava has also been performed to mitigate the effects of tricuspid regurgitation on the central venous system. It is another option for those patients with tricuspid regurgitation, but there are concerns that this procedure might ultimately promote significant hemodynamic deterioration, with ventricularization of the right atrium and increased load on the right ventricle. Ongoing studies are being conducted to assess these effects and the outcomes of this procedure [1].

Do transcatheter interventions of the tricuspid valve affect mortality?

So far, the current evidence we have is from observational studies suggesting improved mortality in patients treated with tricuspid repair/replacement compared to medical therapy [1]. Overall, these transcatheter interventions have shown significant improvement in patient’s symptoms and New York Heart Association (NYHA) functional class, despite only moderate reduction in tricuspid regurgitation severity [1]. There are multiple ongoing trials assessing the impact of these therapies on outcomes.  The TRILUMINATE trial is one example, which is comparing outcomes of tricuspid clipping to medical treatment in patients with functional tricuspid regurgitation.

In conclusion, there are several transcatheter therapies that have been developed for treatment of tricuspid valvular pathologies, most commonly for functional tricuspid regurgitation, in the past few years. Although most of these techniques are still in their early stages, the initial results of the observational data are promising. I look forward to seeing the advances in these therapies in the near future, as we continue to build our experience as operators and familiarize ourselves with these new advanced tools.


“The views, opinions and positions expressed within this blog are those of the author(s) alone and do not represent those of the American Heart Association. The accuracy, completeness and validity of any statements made within this article are not guaranteed. We accept no liability for any errors, omissions or representations. The copyright of this content belongs to the author and any liability with regards to infringement of intellectual property rights remains with them. The Early Career Voice blog is not intended to provide medical advice or treatment. Only your healthcare provider can provide that. The American Heart Association recommends that you consult your healthcare provider regarding your personal health matters. If you think you are having a heart attack, stroke or another emergency, please call 911 immediately.”


Success Does Not Always Leave A ‘Footprint’

Stroke is one of the leading causes of mortality and morbidity in the United States (US). Approximately one‐third of all ischemic strokes are considered cryptogenic, i.e not attributed to large‐vessel atherosclerosis, small‐artery disease, or embolism despite extensive vascular, serological, and cardiac evaluation. Until recently, the relationship between patent foramen ovale (PFO) and cryptogenic stroke was highly debated. Prior to 2006, use of transcatheter based PFO closure procedures were only permitted under Food and Drug Administration (FDA) Humanitarian Device Exemption for recurrent cryptogenic stroke from a PFO after failed conventional medical therapy1. However, the number of eligible patients exceeded the regulatory mandated annual limit of 4,000 patients in 2006. Thus, the Humanitarian Device Exemption process was voluntarily withdrawn1.

In the past two decades, several randomized clinical trials using the Amplatzer PFO Occluder, the Starflex Septal Occluder (NMT Medical Inc, Boston, MA), and the Gore Cardioform Septal Occluder were conducted. Based on long term follow up results of the RESPECT [Randomized Evaluation of Recurrent Stroke Comparing PFO Closure to Established Current Standard of Care Treatment] and REDUCE [GORE® Septal Occluder Device for PFO Closure in Stroke Patients] trials, US FDA approved the Amplatzer PFO Occluder in 2016 and the Gore Cardioform Septal Occluder in 20181,2.  FDA approval for these devices for PFO closure in the United States is to reduce the risk of recurrent ischemic stroke in patients, predominantly between the ages of 18 and 60 years, who have had a cryptogenic stroke due to a presumed paradoxical embolism, as determined by a neurologist and cardiologist following an evaluation to exclude known causes of ischemic stroke2.”

Despite proven efficacy, the use of device based PFO closure techniques have potential risks of several early and late complications, including infection, thrombosis, device dislodgement, atrial wall erosion, perforation, fracture, migration-embolization, allergic reaction to nickel used in PFO occluder device, and induction of arrhythmias3,4. Further, there is need of post procedure antiplatelet therapy after implantation of these devices. These concerns lead to need for a ‘deviceless’ transcatheter system to close PFO. Ruiz et al have performed first-in-man transcatheter suture closure of a PFO in an 18-year-old female with chronic migraine with aura in 2008 without leaving ‘footprint’5.  Results of this novel approach were exciting; however, safety and efficacy of ‘deviceless’ transcatheter techniques on large scale was not established until early results of the NobleStitch EL Italian Registry were reported few months ago6. In this prospective registry, investigators successfully used suture based PFO closure system in 186 (out of 192) patients across 12 sites in Italy with no device related complication on 206±130 days follow-up6. FDA approves the NobleStitch™ EL for Vascular and Cardiovascular suturing in the US (interestingly the technique is not specifically labeled for treating PFOs).

Due to projected increase in numbers of left sided transcatheter interventions (e.g. left atrial appendage closure, arrhythmia ablation and mitral valve interventions), the deviceless technique could be a very attractive option in selected patient population as presence of interatrial septal prosthesis make trans-septal puncture more challenging. Though this technology has huge potential, we should still wait for long term data on safety and efficacy of this no foot print PFO closure system before advocating and supporting its widespread use.



  1. Writing Group Members , American Heart Association Statistics Committee; Stroke Statistics Subcommittee . Heart disease and stroke statistics—2016 update: a report from the American Heart Association. Circulation. 2016; 133:e38–e360
  2. .https://www.fda.gov/newsevents/newsroom/pressannouncements/ucm527096.htm
  3. Luermans JG, Post MC, Yilmaz A. Late device thrombosis after atrial septal defect closure. Eur Heart J. 2010;31:142
  4. Merkler AE, Gialdini G, Yaghi S, Okin PM, Iadecola C, Navi BB, Kamel H. Safety Outcomes After Percutaneous Transcatheter Closure of Patent Foramen Ovale. Stroke. 2017;48:3073-7
  5. Ruiz CE, Kipshidze N, Chiam PT, et al. Feasibility of patent foramen ovale closure with no-device left behind: first-in-man percutaneous suture closure. Catheter Cardiovasc Interv. 2008 Jun 1;71(7):921-6.
  6. Gaspardone A, De Marco F, Sgueglia GA, et al. Novel percutaneous suture-mediated patent foramen ovale closure technique: early results of the NobleStitch EL Italian Registry. EuroIntervention. 2018 Jun 8;14(3):e272-e279.



AHA18: Notes From a Structural Heart Disease Specialist

How can one experience science and scenic beauty together? You know the answer to this, if you attended this year’s annual Scientific Sessions of the American Heart Association (AHA) in the beautiful city of Chicago. AHA18 showcased the latest advancements and studies in the field of cardiovascular medicine and stroke.


AHA Coming Back To The Center Stage

I attended AHA Scientific Sessions for the first time when I was an intern. Science from different sub-specialties of cardiovascular and stroke was truly inspiring and triggered curiosity. However, over the years as I specialized in general cardiology, then interventional cardiology and structural heart disease (SHD), it became increasingly difficult to attend all major scientific meetings every year.  Meetings focused on sub-cardiovascular specialties had taken priority in my schedule in last few years. However, this has changed in 2018. As a SHD specialist I realized the need and importance of a multidisciplinary approach, and science that cuts across various specialties. With widespread adoption of heart team and brain team models, we have realized the importance and benefits of collaboration between physician and surgeons across different specialties.  AHA provides a perfect platform to present and promote such multidisciplinary science.


How Far We Came in the TAVR World

Two separate studies using national administrative databases reported significant reduction in the complications rates associated with transcatheter aortic valve replacement (TAVR).

In the first study, Dr. Sameer Arora and his colleagues at University of North Carolina School of Medicine, Chapel Hill, evaluated the complication rates following both TAVR and surgical aortic valve replacement (SAVR) using the Nationwide Inpatient Sample1.  They included more than 90,000 patients and reported reduction in all cause mortality (4% to 1%), vascular complications (8% to 5%), acute kidney injury (12% to 10%), need for blood transfusions (31% to 10%), and cardiogenic shock (3% to 1%) in patients who underwent TAVR between 2012 and 2015 [P < 0.001 for all].

However, there was an increase in the need for a permanent pacemaker implantation (2% to 12% %; P < 0.001). They also noted trends towards improvement in outcomes with SAVR during same period. Improvement in device profile and valve design, operator experience, and inclusion of patients with lower baseline risk could explain these outcomes with TAVR.

In the second study, Dr. Rajat Kalra, MBChB and colleagues at University of Minnesota, Minneapolis, analyzed rates of new-onset atrial fibrillation and its association with clinical outcomes among patients who underwent TAVR (N=48,715) and SAVR (N=122,765), also using the Nationwide Inpatient Sample from 2012 to 20152. The study reported rates of new-onset atrial fibrillation as 50.4% and 50.1% for TAVR and SAVR respectively. They also noted higher in-hospital mortality, and post procedure stroke, among patients who had new-onset AFib post TAVR or SAVR.

Results from both of these studies are in coherence with findings from clinical trials and our experience with TAVR. However, due to lack of randomization, long term follow up, potential confounders and potential of inappropriate coding, caution should be exercise in extrapolating results of these studies or comparing TAVR with SAVR based on such data.


Flyer from Future

In addition to various studies and presentations from all across the nation and the international scientific community, AHA18 had dedicated sessions for Structural Heart Disease, 3D imaging, and Artificial Intelligence, giving us a glimpse of the near future for SHD. Cardiac imaging is critical to plan and perform any transcatheter based structural heart disease procedure, and 3D printing has potential to revolutionize the treatment planning of patients with SHD as highlighted by Dr. Frank Rybicki (University of Ottawa) during his presentation at AHA18. A potential role of 3D bioprinting for preoperative planning for TAVR and SAVR and the future of this technology was further emphasized in another interesting talk “Personalized Care: Print your own valve,” by Dr. Kamal Khabbaz (Beth Israel Deaconess Medical Center, Harvard Medical School, MA).

My experience during 2018 session has reinforced my believe that AHA has the potential to be ‘The Platform’ to present and promote SHD science.



  1. Arora S. Trends in inpatient complications after transcatheter and surgical aortic valve replacement in the TAVR era. Presented at: AHA 2018. November 11, 2018. Chicago, IL.
  2. Kalra R. New-onset atrial fibrillation after aortic valve replacement: evaluation of a national cohort. Presented at: AHA 2018. November 12, 2018. Chicago, IL.