Aortic Stenosis and its treatment


Your Heart

  Your heart pumps blood through your body, collects it back, pumps it to the lungs to add oxygen, and starts all over again. The heart has four chambers and four valves that open and close to control the flow of blood in and out of the heart.

  Heart valves operate like one-way gates. They open to allow blood flow through your heart and out to your body. They close to stop blood from flowing back into the heart after it has been expelled. The valves permit blood to flow in only one direction, or pathway, through your heart.

A healthy aortic valve

A healthy aortic valve opens wide to allow proper blood flow and closes tightly to stop blood flow


Aortic Valve Stenosis

  The aortic valve is positioned at the top of the left ventricle and leads to the aorta, the major large blood vessel that circulates oxygenated blood to your body. The valve has flaps (called cusps or leaflets) that are forced open when the left ventricle contracts, allowing blood to flow into the aorta. The leaflets then close to prevent the blood from leaking back into the ventricle.

  Aortic valve stenosis occurs when calcium deposits on the valve cause the leaflets to become stiff. As the condition progresses, the valve opening narrows, obstructing blood flow and forcing the heart to pump harder.

A stenotic aortic valve

A stenotic aortic valve is unable to open wide, obstructing blood flow and may fail to close properly


  Symptoms of severe aortic stenosis include:

  • Chest pain or tightness (angina)
  • Feeling faint or fainting upon exertion
  • Shortness of breath upon exertion
  • Reduced exercise capacity

  Remember, however, that heart valve disease often occurs with no outward symptoms and may go undetected.

  Untreated severe aortic stenosis often leads to heart failure, with symptoms of fatigue, shortness of breath, swollen ankles and feet, and possible sudden death.

  Treatment for severe symptomatic aortic stenosis is essential to prolong your life. There are no medications to reverse the stenosis. Aortic valve replacement is the standard treatment for severe aortic stenosis. Without treatment, a large percentage of the people with severe aortic stenosis who are experiencing symptoms will die within 1-2 years.

Treatment Options

  Replacement of the aortic valve is typically done in a surgical procedure, and depending on your condition and your doctor’s assessment, a transcatheter valve replacement may be selected.

Surgical Valve Replacement

Surgical valve being sewn into place  Surgical aortic valve replacement, or SAVR, is done through an open-heart procedure; the chest is opened up so the surgeon can access the heart and the patient is placed on cardiopulmonary bypass.

  During surgical valve replacement, the surgeon removes the narrowed valve and replaces it with either a mechanical valve (metal) or a biological valve (constructed of animal or human tissue). Different valve types have different benefits and risks. You and your doctor will choose a valve best suited to you based on your individual lifestyle, age and medical condition.

  Benefits of SAVR. Each year, more than 250,000 heart valve surgeries take place across the world. Surgical valve replacement has been performed for many years and has consistently produced excellent results in lengthening patients’ lives and improving their quality of life.

Surgical valve being sewn into place

Transcatheter Valve Implantation

Valve delivery via catheter and balloon inflation  Transcatheter aortic valve implantation, or TAVI, enables replacement of the aortic valve without opening the chest. This less invasive procedure is now available for patients considered to be inoperable or at high-risk for open-heart surgery. In the TAVI procedure, the valve is squeezed down onto a balloon, inserted into the body via a catheter (a long flexible tube), and tracked to the heart for implantation. This can be done without opening the chest or using the heart-lung pump. The catheter may be inserted through the femoral artery (in the groin) or through a small incision in the chest over the heart. When the valve is positioned inside the faulty aortic valve, the balloon is inflated and the valve is precisely positioned.

  Benefits of TAVI include a shorter procedure, less pain, and a shorter stay in the hospital. Because it is non-invasive, recovery time is significantly shorter than after open-heart surgery – about 2 to 4 weeks instead of 6 to 8 weeks. As with surgical heart valve replacement, TAVI provides both short- and long-term relief of symptoms, normal aortic valve function and improvement in your overall life expectancy and functioning.

Risks

  Potential risks of valve replacement vary significantly from person to person depending on age, overall health, and other factors. Your doctor will discuss the risks in detail before you consent to the procedure. Your doctor will further evaluate your condition and determine if you should be referred to a heart team. His analysis will include a comprehensive physical examination plus evaluating the results of a number of blood tests and imaging studies which may include an ECG, an echocardiogram, a coronary angiogram, and/or other tests. It is important to note, however, that untreated severe aortic stenosis poses a high risk of progressive symptoms or death.

Transcatheter Aortic Valve Implantation

  If your aortic valve is severely diseased, you may require replacement of your valve. However you could be advised that an open heart surgery carries too high a risk for you. In this case, you may be eligible to receive an alternative treatment called TAVI (Transcatheter aortic valve implantation). With this novel approach introduced in the UK in 2007, it is possible to replace your aortic valve without requiring a full open heart surgery.

Who can have a TAVI?

  According to the NICE Interventional Procedure guidance (March 2012) TAVI can be offered routinely as a treatment option to patients with aortic stenosis who cannot have open heart surgery because of poor health or technical difficulties, provided that doctors are sure that:

  • the patient understands what is involved and agrees to the treatment, and
  • the results of the procedure are monitored.

Guidelines issued in August 2012 by the European Association of Cardio Thoracic Surgery (EACTS) and the European Society of Cardiology (ESC) state the following:

“TAVI is recommended in patients with severe symptomatic AS who are, according to the ‘heart team’, considered unsuitable for conventional surgery because of severe comorbidities.”

“Among high-risk patients who are still candidates for surgery, the decision should be individualized. TAVI should be considered as an alternative to surgery in those patients for whom the ‘heart team’ favours TAVI, taking into consideration the respective advantages/disadvantages of both techniques.”

What is involved with the procedure?

  TAVI is an alternative to open heart surgery and is considered as a minimally invasive approach. This heart surgery can be performed using echocardiographic and fluoroscopic guidance for visualization during implantation.
  During the procedure a valve (Figure 1: a balloon expandable stent combined with a bovine pericardial bioprosthetic tissue valve) is reduced to size and placed on a delivery catheter (Figure 2).

Figure 1: The valve

  The delivery catheter can then be inserted in the femoral artery through a small incision at the top of the leg (transfemoral approach) or between the ribs (transapical and transaortic approaches).
  Once in the heart, the valve is positioned and deployed across the patient’s diseased aortic valve.

What happens after the operation?

  After a short hospital length of stay, it is possible to be discharged home with a prescription of clopidogrel (for 3 months) and aspirin (for life).

Who can perform TAVI in the UK?

  Only selected accredited centres with trained multidisciplinary heart teams can perform this procedure.
A list of hospitals is available to you here.

Where can I find more information?

Is TAVI available on the NHS? Please refer to the following links:
For England: Clinical Commissioning Policy: TAVI For Aortic Stenosis
For Scotland: First TAVI ops success
For Wales: Specialised Services Policy: CP58

Published experience with TAVI: Transcatheter Aortic-Valve Implantation for Aortic Stenosis in Patients Who Cannot Undergo Surgery
Martin B. Leon, M.D., Craig R. Smith, M.D., Michael Mack, M.D., D. Craig Miller, M.D., Jeffrey W. Moses, M.D., Lars G. Svensson, M.D., Ph.D., E. Murat Tuzcu, M.D., John G. Webb, M.D., Gregory P. Fontana, M.D., Raj R. Makkar, M.D., David L. Brown, M.D., Peter C. Block, M.D., Robert A. Guyton, M.D., Augusto D. Pichard, M.D., Joseph E. Bavaria, M.D., Howard C. Herrmann, M.D., Pamela S. Douglas, M.D., John L. Petersen, M.D., Jodi J. Akin, M.S., William N. Anderson, Ph.D., Duolao Wang, Ph.D., and Stuart Pocock, Ph.D. for the PARTNER Trial Investigators. N Engl J Med 2010; 363:1597-1607. October 21, 2010
http://www.nejm.org/doi/full/10.1056/NEJMoa1008232

Transcatheter versus Surgical Aortic-Valve Replacement in High-Risk Patients
Craig R. Smith, M.D., Martin B. Leon, M.D., Michael J. Mack, M.D., D. Craig Miller, M.D., Jeffrey W. Moses, M.D., Lars G. Svensson, M.D., Ph.D., E. Murat Tuzcu, M.D., John G. Webb, M.D., Gregory P. Fontana, M.D., Raj R. Makkar, M.D., Mathew Williams, M.D., Todd Dewey, M.D., Samir Kapadia, M.D., Vasilis Babaliaros, M.D., Vinod H. Thourani, M.D., Paul Corso, M.D., Augusto D. Pichard, M.D., Joseph E. Bavaria, M.D., Howard C. Herrmann, M.D., Jodi J. Akin, M.S., William N. Anderson, Ph.D., Duolao Wang, Ph.D., and Stuart J. Pocock, Ph.D. for the PARTNER Trial Investigators. N Engl J Med 2011; 364:2187-2198. June 9, 2011
http://www.nejm.org/doi/full/10.1056/NEJMoa1103510

Transcatheter Aortic-Valve Replacement for Inoperable Severe Aortic Stenosis
Raj R. Makkar, M.D., Gregory P. Fontana, M.D., Hasan Jilaihawi, M.D., Samir Kapadia, M.D., Augusto D. Pichard, M.D., Pamela S. Douglas, M.D., Vinod H. Thourani, M.D., Vasilis C. Babaliaros, M.D., John G. Webb, M.D., Howard C. Herrmann, M.D., Joseph E. Bavaria, M.D., Susheel Kodali, M.D., David L. Brown, M.D., Bruce Bowers, M.D., Todd M. Dewey, M.D., Lars G. Svensson, M.D., Ph.D., Murat Tuzcu, M.D., Jeffrey W. Moses, M.D., Matthew R. Williams, M.D., Robert J. Siegel, M.D., Jodi J. Akin, M.S., William N. Anderson, Ph.D., Stuart Pocock, Ph.D., Craig R. Smith, M.D., and Martin B. Leon, M.D. for the PARTNER Trial Investigators. N Engl J Med 2012; 366:1696-1704. May 3, 2012
http://www.nejm.org/doi/full/10.1056/NEJMoa1202277

Two-Year Outcomes after Transcatheter or Surgical Aortic-Valve Replacement
Susheel K. Kodali, M.D., Mathew R. Williams, M.D., Craig R. Smith, M.D., Lars G. Svensson, M.D., Ph.D., John G. Webb, M.D., Raj R. Makkar, M.D., Gregory P. Fontana, M.D., Todd M. Dewey, M.D., Vinod H. Thourani, M.D., Augusto D. Pichard, M.D., Michael Fischbein, M.D., Ph.D., Wilson Y. Szeto, M.D., Scott Lim, M.D., Kevin L. Greason, M.D., Paul S. Teirstein, M.D., S. Chris Malaisrie, M.D., Pamela S. Douglas, M.D., Rebecca T. Hahn, M.D., Brian Whisenant, M.D., Alan Zajarias, M.D., Duolao Wang, Ph.D., Jodi J. Akin, M.S., William N. Anderson, Ph.D., and Martin B. Leon, M.D. for the PARTNER Trial Investigators. N Engl J Med 2012; 366:1686-1695. May 3, 2012
http://www.nejm.org/doi/full/10.1056/NEJMoa1200384

TAVI Guideline from the National Institute for Health and Care Excellence for England and Wales:
http://www.nice.org.uk/nicemedia/live/11914/58647/58647.pdf

European guidelines on TAVI from the European Association of Cardio Thoracic Surgery (EACTS) and the European Society of Cardiology (ESC).Vahanian A, Alfieri OR, Andreotti F, Antunes MJ, Gonzalo Baron-Esquivias G, Baumgartner H, et al. Valvular Heart Disease (Management of); August 2012 (pages 17.19):
http://www.escardio.org/Guidelines_Valvular_Heart_Dis_FT.pdf