The Heart Team
The cornerstone for a comprehensive heart valve service
Professor Olaf Wendler MD PhD FrCs is a Consultant Cardiothoracic Surgeon at King’s College Hospital and Bupa Cromwell Hospital.
The number of patients affected by heart valve disease is rising due to the changing demographics of our population. They not only suffer from symptoms of heart failure, but face an impaired prognosis if adequate treatment is withheld. Early referral and access to cardiac diagnostic tests, as well as the opportunity to offer a comprehensive heart valve service, is the key to an optimal outcome.
Originally heart valve treatment revolved around valve replacement using open-heart surgery, and only patients with severe symptoms and in otherwise good health were considered for this. With improvements in cardiac diagnostics, new surgical and interventional treatment options, and a growing appreciation of the poor prognosis associated with conservative management, heart valve therapy can now be appropriately tailored to patients’ individual needs (1).
I focus here on left sided heart valve disease, as the aortic and mitral valve are more often affected by pathological changes, and highlight the importance of the ‘Heart Team’. The team comprises a heart valve/failure cardiologist, interventional cardiologist, cardiac imaging specialist and a cardiac surgeon. They provide a comprehensive heart valve service, offering innovative therapies such as minimally invasive heart valve repair surgery, as well as transcatheter based interventional techniques (2).
Trans-thoracic and trans-esophageal echocardiography are now the gold standard for cardiac imaging. 3D echocardiography provides exact information on heart valve anatomy, enabling accurate planning for surgical or interventional treatment(3). This information helps to estimate the likelihood of heart valve repair in certain patients, and makes it possible to identify the best therapeutic option.
In addition, heart valve stress echocardiography (performed whilst patients are exercising) allows the identification of patients with significant heart valve disease at an early stage, when treatment will provide the best outcomes and lowest procedural risks.
Aortic Valve Disease
The aortic valve is the outlet valve of the left ventricle and part of the aortic root. It is most often affected by calcification of the valve cusps, which results in aortic stenosis. However thoracic aortic disease with dilatation of the aortic root or ascending aorta can also pull the aortic valve cusps apart, resulting in aortic regurgitation (Fig 1).
Aortic stenosis usually affects the elderly (it is found in 4% of octogenarians) and carries a very poor prognosis, with two-year mortality of up to 50%. Historically it was only treated using aortic valve replacement during open-heart surgery. Although less invasive surgical techniques with limited chest openings (Fig 2) and reduced operation times have improved outcomes, the number of elderly patients with co-morbidities has also steadily increased.
This explains the development of transcatheter aortic valve implantation (TAVI), where an aortic prosthesis is implanted without opening the chest and stopping the heart. Since the first TAVI was performed in 2002 the procedure has evolved into a reproducible technique, with over 200,000 procedures performed worldwide. Trials have shown that it is a particularly attractive treatment option for patients with symptomatic aortic stenosis who are at high-risk or unsuitable for open-heart surgery (Fig 3) (4).
In contrast to aortic stenosis, aortic regurgitation is often not an isolated disease of the aortic valve, but (in 70% of cases) found as a result of aortic root dilatation. This weakness of the aortic root can be found as a result of isolated structural defects of the aortic wall (e.g. Marfan’s disease), or in patients with combined pathology of the aortic valve and aortic wall (e.g. those with bicuspid aortic valves, Fig 4).
Symptoms in these patients usually arise according to the degree of aortic regurgitation. Their prognostic risk is often determined by the degree of aortic dilatation, and rises steeply after aortic diameters are larger than 45mm. As aortic aneurysms often don’t produce symptoms, early identification of patients at risk and regular assessment of their aortic diameters using echocardiography or tomography enables us to determine optimal timing for surgical intervention.
As these patients are often younger and face potential future prosthetic valve complications or treatment of their aorta, they benefit from the option of aortic valve/root repair surgery with full preservation of the native aortic valve (Fig 5). My team achieves 98% - 99% survival in patients who undergo elective surgery before complications occur (5).
A repair of the aortic root eliminates the long-term complications of a heart valve prosthesis, and avoids anticoagulation with its risk of bleeding or stroke. Aortic valve repair also restores normal haemodynamic heart valve function, supporting full recovery of the left ventricular function.
Mitral Valve Disease
The mitral valve is part of the left ventricle, and mitral regurgitation due to left ventricular dilatation is the most commonly found pathology. Treatment options must maintain the integrity of the mitral valve and the left ventricle by preserving its subvalvular apparatus.
Mitral valve repair is an optimal treatment option to preserve left ventricular function in patients undergoing mitral valve surgery. Surgical success relies on the team’s experience and access to the newest devices, so that even complex pathologies such as prolapse of the anterior leaflet or bi-leaflet prolapses can be addressed appropriately (Fig 6) (6).
Current guidelines recommend that surgeons operating on patients with degenerative mitral regurgitation should achieve a valve repair in more than 90% of patients (our current repair rates are around 98%). They also stipulate that surgery should only be offered to asymptomatic patients if mitral valve repair is feasible. This increases the need for optimal preoperative assessment of the mitral valve, and 3D echocardiography is key to predicting the likelihood of repair success (2).
The development of interventional mitral valve therapies has been more challenging than for the aortic valve due to the complex anatomy and its interaction with the left ventricle. Multiple techniques are currently under observation and the MitraClip™ is currently the most advanced device used, but this has limitations.
Mitral Valve stenosis
Previously, stenotic mitral valves were most often found in young patients with congenital abnormalities, or in patients with rheumatic disease. Whilst rheumatic disease has steadily decreased in the UK, there are still a significant number of elderly and foreign patients presenting with this.
Balloon-valvuloplasty is an established treatment option, particularly for young patients with no major concomitant mitral regurgitation. However, in patients with complex disease, mitral valve replacement is usually the only effective treatment option. The subvalvular apparatus must be preserved during surgery, otherwise patients are at risk of postoperative left ventricular failure.
Concomitant tricuspid valve disease and atrial fibrillation also need to be corrected, or the atrial appendix closed during surgery, to prevent long-term complications such as right heart failure or stroke.
Prosthetic Valve Failure
In patients with failing biological valve prostheses, transcatheter valve implantation is a new, less invasive and attractive therapeutic option. Similar to TAVI, a biological heart valve prosthesis is inserted into the previously implanted bioprosthesis without re-opening the chest or arresting the heart. We routinely perform these in patients with failing aortic and biological prostheses, with strong outcomes(7).
Given the growing number of patients suffering from heart valve disease, and the increasing surgical and interventional treatment options available, heart valve treatment is best provided by an established Heart Team of cardiologists and surgeons. This allows optimal, timely diagnosis, and individualised care not only in terms of the acute treatment, but also with respect to future follow-up and post-operative medical therapy.
Excellent outcomes rely on an early, accurate diagnosis, and while conservative treatment may be appropriately recommended in the early stages, patients should be discussed by a Heart Team so that optimal timings for more invasive treatment are not missed.
The co-contributors to this article are:
1. Vahanian A, Alfieri O, Andreotti F et al. Guidelines on the management of valvular heart disease (version 2012): the Joint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS). Eur J Cardiothorac Surg. 2012 Oct;42(4):S1-44.
2. Naber CK, Prendergast B, Thomas M, Vahanian A, Lung B, Rosenhek R, Tornos P, Otto CM, Antunes MJ, Kappetein P, Lange R, Wendler O. An interdisciplinary debate initiated by the European Society of Cardiology working group on Valvular Heart Disease. Eurointervention 2012;7(11):1257-1274.
3. Smith L, Bhan A, Dworakowski R, Thomas MR, MacCarthy PA, Wendler O,
Monaghan M. Real-time 3D Transesophageal Echocardiography Adds Value to Transcatheter Aortic Valve Implantation. J Am Soc Echocardiography 2013;26:359-369.
4. Dworakowski R, Wendler O, Bhan A, Smith L, Pearson P, Alcock E, Rajagopal
K, Brickham B, Dew T, Byrne J, Monaghan MJ, Sherwood R, Shah AM, MacCarthy PA. Successful transcatheter aortic valve implantation (TAVI) is associated with transient left ventricular dysfunction. Heart. 2012;98:1641-1646.
5. HJ Schäfers, F Langer, D Aicher, T Graeter, O Wendler. Remodelling of the aortic root and reconstruction of the bicuspid aortic valve. Ann Thorac Surg 2000; 70:542-546.
6. LF Dübener, O Wendler, N Nikoloudakis, T Georg, R Fries, HJ Schäfers. Mitral-valve repair without annuloplasty rings: results after repair of anterior leaflet versus posterior-leaflet defects using plytetrafluoroethylene sutures for chordal replacement. Eur J Cardiothorac Surg 2000; 17 (3):206-212.
7. EI Kapetanakis, R Dworakowski, P MacCarthy, A El-Gamel, A Bhan, M Monaghan, O Wendler. Transapical aortic valve implantation in a patient with stentless valve degeneration. Eur J Cardio-thoracic Surg 2011:1051-1053.
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