181. Aortic Stenosis and the Story of TAVR – Historical Perspective & Future Directions with Dr. Jon Resar

CardioNerds, Daniel Ambinder and CardioNerds Academy Program Director, Dr. Tommy Das (Cardiology fellow, Cleveland Clinic), Dr. Jacqueline Latina (Structural heart fellow, Johns Hopkins) discuss aortic stenosis and the story of TAVR from both the historical perspective and in terms of future directions with Dr. Jon Resar, Professor of Medicine and Director of the Adult Catheterization Laboratory and Interventional Cardiology at the Johns Hopkins Hospital. This episode is brought to you for Heart Valve Disease Awareness Day. Audio editing by CardioNerds Academy Intern, Shivani Reddy.

As many as 11 million Americans have heart valve disease (HVD)—a potentially disabling and deadly disease—yet 3 out of 4 Americans know little to nothing about heart valve disease. Learn more about valve disease.

PearlsNotesReferencesGuest ProfilesProduction Team

Pearls and Quotes – Aortic Stenosis and the Story of TAVR

  1. In the previous century, patients with severe aortic stenosis who were treated “medically” had 50% mortality over 2 years after developing symptoms. Balloon aortic valvuloplasty was initially touted as extremely “efficacious” for aortic stenosis but follow-up studies showed that the improvement in symptoms were not durable, and long-term prognosis was dismal.
  2. The PARTNER Trial started enrolling in 2007 in extreme risk patients – patients who were not surgical candidates. In 2010, the PARTNER trial was published and TAVR blew away the “standard of care” in inoperable patients at the time, cutting outcomes in half (composite of death and repeat hospitalization). The PARTNER trial studied balloon expandable intra-annular valve implantation. The CoreValve trial studied self-expanding supra-annular valve implantation and was published in 2014.
  3. The “Heart Team” approach entails collaborative decision making between cardiologists and cardiac surgeons to personalize management for patients.
  4. Both intra-annular and supra-annular valves show non-inferior outcomes to surgery in intermediate and low risk patients.
  5. Revascularization prior to TAVR is an evolving arena; the trend has been interventionalists performing fewer PCIs prior to TAVR given the benefit is not clear if angina is not a prominent symptom.

Show notes – Aortic Stenosis and the Story of TAVR

(TAVR/TAVI are using interchangeably)

CardioNerds Aortic Stenosis
CardioNerds Aortic Stenosis, updated 1.20.21

1. In the 1990s, patients with severe aortic stenosis (AS) who were deemed to be at high surgical risk would weigh the risks of surgery and prolonged recovery. Balloon Aortic Valvuloplasty (BAV) was first performed by Dr. Alain Cribier in 1986. The technique was based on the foundation of pulmonary valvuloplasty performed initially in 1982 by Drs. Jean Kan and Bob White, and mitral valvuloplasty in 1984. BAV was initially touted as an efficacious cure for aortic stenosis, but unfortunately it had a high restenosis rate as well as high risks for stroke and vascular complications (no closure devices at that time) with an overall poor long-term prognosis. Balloon aortic valvuloplasty was primarily used for decompensated Class IV heart failure in non-surgical candidates.

2. Transcatheter aortic valve replacement (TAVR/TAVI) was developed and first performed in human in 2002.(1) This was performed by Dr. Alain Cribier in France in 2002, initially by trans-septal approach and then by retroaortic approach. Here is a representative diagram of the procedure.

Figure: Transcatheter Aortic-Valve Replacement. The transcatheter valve is positioned at the level of the native aortic valve during the final step of valve replacement, when the balloon is inflated within the native valve during a brief period of rapid ventricular pacing. The delivery system is shown after it has traversed the aorta retrograde over a guidewire from its point of insertion in the femoral artery (transfemoral placement). Before balloon inflation, the valve and balloon are collapsed on the catheter (dark blue) and fit within the sheath (blue). After balloon inflation, the calcified native valve (upper panel) is replaced by the expanded transcatheter valve (lower panel, shown in short-axis view from the aortic side of the valve). Smith CR et al. N Engl J Med 2011;364:2187-2198.

3. The PARTNER trial was first published in a landmark NEJM article in extreme surgical risk patients comparing TAVR (with a balloon-expandable aortic valve implant) versus stndard “medical” therapy of aortic stenosis. TAVR markedly reduced the composite outcome of all-cause mortality and repeat hospitalization in these patients.(2)  PARTNER then compared TAVR to aortic valve surgery in high risk patients, and TAVR performed quite well, though there were more strokes and vascular complications in the TAVR group compared to surgery.(3)

Figure: PARTNER Trial Time-to-Event Curves for the Primary End Point and Other Selected End Points. Leon MB et al. N Engl J Med 2010;363:1597-1607.

4. CoreValve/Medtronic then published their results for their self-expanding valve, enrolling over 1400 participants.(4) The rate of death in the TAVR group was non-inferior to the SAVR group, and a subsequent test for superiority actually showed TAVR was superior to surgery in these high risk patients.

Figure: Kaplan–Meier Cumulative Frequency of Death from Any Cause. The rate of death from any cause in the TAVR group was noninferior to that in the surgical group (P<0.001). A subsequent test for superiority at 1 year showed that TAVR was superior to surgical replacement (P=0.04). The inset shows the same data on an enlarged y axis. Adams DH et al. N Engl J Med 2014;370:1790-1798.

5. Both balloon expandable (PARTNER 3) and self-expanding valves (Evolut Low Risk) have since been studied in intermediate and low surgical risk patients.(5-8)  In low risk patients, the balloon expandable valve showed the rate of the composite of death, stroke, or rehospitalization at 1 year was significantly lower with TAVR than with surgery. In low risk patients, TAVR with a self-expanding supraannular bioprosthesis was noninferior to surgery with respect to the composite end point of death or disabling stroke at 24 months.

6. Coronary artery disease in TAVR patients: the decision for coronary revascularization prior to TAVR is complex and practice is evolving. Initially, most patients were being revascularized for obstructive coronary artery stenosis electively prior to TAVR. More recently, if the disease is not proximal (or a small area of myocardium at risk) and if angina is not a prominent symptom, we have moved towards deferring coronary revascularization.

References – Aortic Stenosis and the Story of TAVR

1. Cribier A, Eltchaninoff H, Tron C et al. Early experience with percutaneous transcatheter implantation of heart valve prosthesis for the treatment of end-stage inoperable patients with calcific aortic stenosis. J Am Coll Cardiol 2004;43:698-703.

2. Leon MB, Smith CR, Mack M et al. Transcatheter Aortic-Valve Implantation for Aortic Stenosis in Patients Who Cannot Undergo Surgery. New England Journal of Medicine 2010;363:1597-1607.

3. Smith CR, Leon MB, Mack MJ et al. Transcatheter versus Surgical Aortic-Valve Replacement in High-Risk Patients. New England Journal of Medicine 2011;364:2187-2198.

4. Adams DH, Popma JJ, Reardon MJ et al. Transcatheter Aortic-Valve Replacement with a Self-Expanding Prosthesis. New England Journal of Medicine 2014;370:1790-1798.

5. Leon MB, Smith CR, Mack MJ et al. Transcatheter or Surgical Aortic-Valve Replacement in Intermediate-Risk Patients. N Engl J Med 2016;374:1609-20.

6. Reardon MJ, Van Mieghem NM, Popma JJ et al. Surgical or Transcatheter Aortic-Valve Replacement in Intermediate-Risk Patients. N Engl J Med 2017;376:1321-1331.

7. Popma JJ, Deeb GM, Yakubov SJ et al. Transcatheter Aortic-Valve Replacement with a Self-Expanding Valve in Low-Risk Patients. N Engl J Med 2019;380:1706-1715.

8. Mack MJ, Leon MB, Thourani VH et al. Transcatheter Aortic-Valve Replacement with a Balloon-Expandable Valve in Low-Risk Patients. N Engl J Med 2019;380:1695-1705.

Guest Profiles

Dr. Jon Resar

Dr. Jon Resar received his medical degree from the Medical College of Wisconsin and completed fellowships in cardiovascular medicine and interventional cardiology at The Johns Hopkins Hospital where he serves as the director of the adult cardiac catheterization and serves as Professor of Medicine. He has been a pioneer in percutaneous management of coronary artery disease and structural heart disease.

Jacqueline Latina, MD
Dr. Jackie Latina

Dr. Jacqueline Latina is currently a Structural Heart Fellow at Johns Hopkins. She was born and raised in the suburbs of Boston, MA, but fortunately escaped without a Boston accent. She is a graduate of Princeton University with an A.B. in chemistry. She earned her M.D. at Tufts University School of Medicine. Her internship and internal medicine residency were completed at Mount Sinai Hospital in New York City, where she stayed on for an American Heart Association postdoctoral research fellowship. She completed an M.S. in clinical research methods at the Columbia Mailman School of Public Health during that time. She completed general and interventional cardiology fellowships at Johns Hopkins.

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