Percutaneous aortic valve replacement is an emerging procedure for the treatment of aortic valve disease with a potential to supplant surgical aortic valve replacement in the near future.
Aortic stenosis is occurring increasingly in the elderly. Aortic valve replacement in older individuals with many comorbid conditions is associated with high surgical mortality and morbidity. Advancement in percutaneous coronary intervention (PCI) and drug-eluting stent treatment of coronary artery disease has contributed to a dramatic reduction in the rate of coronary bypass surgery. With recent developments in percutaneous aortic valve replacement, cardiac surgeons will soon encounter a decline in valve surgeries.
In August 2003, the first patient, a 73-year-old man with severe aortic valve stenosis and high risk for surgical intervention, underwent percutaneous aortic valve replacement for compassionate use. He was treated with a first-generation device using an anterograde approach and survived for the first 36 h. However, he died 4 days later, due to catheter-induced injury to the anterior mitral leaflet causing severe mitral regurgitation. Despite the first negative experience, new devices have been developed and successfully deployed in both the anterograde and retrograde approaches.
The first successful percutaneous deployment of an aortic valve was reported in 2003 in a 57-year-old man with severe aortic stenosis and cardiogenic shock using an anterograde approach Citation[1,2]. The retrograde access to the aortic valve is a more direct approach by advancing the catheter into the aorta across the valve. It has the distinct advantage of avoiding trans-septal puncture and manipulation through the mitral valve. However, it has the disadvantage of a large arterial puncture site and difficulty advancing a bulky catheter across the aortic arch with the risk of injury to the aorta. Since the introduction of this technique, over 100 cases have been performed worldwide, mostly using the retrograde approach.
The largest series of patients undergoing this procedure were recently reported from Canada and Germany. Webb and colleagues attempted this technique in 50 patients using a retrograde approach via the femoral artery Citation[3]. Valve implantation was successful in 86% of patients. Intraprocedural mortality was only 2%. Procedural success was dependent on the operator’s experience and was raised to 96% after treating the first 25 patients Citation[3]. The mortality rate was 12% after 30 days in their cohort, which was lower than the expected mortality rate of 28%, using the European system for Cardiac Operative Risk Score Citation[4] (the European risk score was developed to estimate cardiac surgical mortality based on risk calculation using over ten parameters that are associated with increased surgical mortality, such as age, renal failure and ejection fraction). Improvement in valve and cardiac function was maintained for 1 year without any structural valve deterioration.
In Germany, Grube and his team published the largest series of patients undergoing percutaneous aortic valve replacement using second- and the newest third-generation device compatible with 18-Fr sheath size Citation[5]. They enrolled 86 patients with an 88% success rate. Procedural mortality was only 6% and the total 30-day mortality was 12%, which was much lower than the expected surgical mortality risk of 23% in their population. Initial devices required surgical intervention for access and sheath removal due to a very large sheath size. However, the introduction of an 18-Fr device eliminated the multidisciplinary approach and transferred this procedure to a truly prercutaneous approach Citation[5].
Despite these encouraging results, this technique is in infancy and requires expertise for safe and accurate deployment of this device. These studies have significant limitations. Many patients whose annulus is too small or too large were excluded. Peripheral vascular disease-limiting access site, and nonrevascularized coronary artery disease are relative contraindications to this procedure. There are significant serious adverse events associated with this procedure, such as myocardial infarction, cardiac tamponade, stroke, peripheral embolism, injury to the aorta, perivalvular leak and access site injury Citation[3,5]. Operative experience is important for better outcome and success. Furthermore, long-term durability and safety of these valves in comparison to surgically implanted valves need to be evaluated and studied carefully. As technology advances, smaller devices with better performance will emerge. It will only be a matter of time before percutaneous aortic valve replacement, similar to angioplasty for the patient with coronary artery disease, will be the initial treatment for patients with aortic valve disease.
Financial & competing interests disclosure
The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
No writing assistance was utilized in the production of this manuscript.
References
- Cribier A, Eltchaninoff H, Tron C. First human transcatheter implantation of an aortic valve prosthesis in a case of severe calcific aortic stenosis. Ann. Cardiol. Angeiol. (Paris)52(3), 173–175 (2003).
- Cribier A, Eltchaninoff H, Bash A et al. Percutaneous transcatheter implantation of an aortic valve prosthesis for calcific aortic stenosis: first human case description. Circulation106(24), 3006–3008 (2002).
- Webb JG, Pasupati S, Humphries K et al. Percutaneous transarterial aortic valve replacement in selected high-risk patients with aortic stenosis. Circulation116(7), 755–763 (2007).
- Chen CC, Wang CC, Hsieh SR, Tsai HW, Wei HJ, Chang Y. Application of European system for cardiac operative risk evaluation (EuroSCORE) in coronary artery bypass surgery for Taiwanese. Interact. Cardiovasc. Thorac. Surg.3(4), 562–565 (2004).
- Grube E, Schuler G, Buellesfeld L et al. Percutaneous aortic valve replacement for severe aortic stenosis in high-risk patients using the second- and current third-generation self-expanding CoreValve prosthesis: device success and 30-day clinical outcome. J. Am. Coll. Cardiol.50(1), 69–76 (2007).