“All the companies in the United States and Europe and Japan, they have experts, and the experts are surgeons and they said it is absolutely not possible. We would kill the patients on the table.” – Alain Cribier, Cardiologist, Innovator of the TAVR Procedure
On April 9, 2002, a 57-year old man presented at the Cardiology Clinic of L’Hôpital Charles Nicolle, in Rouen, France. He had severe aortic stenosis with a valve area of 0.6 sq cm (normal is 4 – 6 sq cm), a mean gradient of 30 mmHg (normal < 5 mm Hg), was in cardiogenic shock (systolic blood pressure was 80) and had a left ventricular ejection fraction of 14% (normal 55 – 60%). Due to all his co-morbidities – chronic pancreatitis, severe vascular disease, silicosis, history of lung cancer – he had been refused surgery at several centers.
A cardiologist at the hospital, Alain Cribier, had in 1985, successfully used a ballon to open up stenotic aortic valves, a procedure termed ballon valvuloplasty.
That day in April of 2002, Dr Cribier performed balloon valvuloplasty on the aortic valve of the patient. He improved initially with the gradient falling to 13 mm Hg and the area increasing to 1.07 sq cm. However over the next week, the patient’s condition steadily declined. By about the 6th day after the valvuloplasty, his ejection fraction was 8 – 12% and in spite of support with medications, his systolic blood pressure was only 70.
A week after his valvuloplasty, on April 16, 2002, Alain Cribber made a decision that made history and is disrupting cardiac care like not seen since the introduction of cardiac stents about 10 years earlier.
After obtaining permission from the hospital’s Institutional Ethics Committee, he took the patient to the cardiac cath lab where, by accessing the femoral vein in the patient’s groin, he introduced an investigational heart valve to replace the stenotic aortic valve of the sick 57-year-old man. He didn’t open the patient’s chest like was the norm. He did everything from outside the body! The patient’s condition improved significantly. He however died 4 months later from unrelated issues.
Dr Alain Cribber had just performed the first percutaneous valve replacement in a human! The rest, like they say, is history.
In 2004, Edwards bought the company Dr Cribier had started to make the valves and the equipment to deploy it for $125 million.
That procedure, now called Transcatheter Aortic Valve Replacement (TAVR), has been approved by the FDA for patients with aortic stenosis (NOT regurgitation) who are terrible surgical candidates. These are patients not expected to survive surgery. It is presently performed in about 400 centers in the US. As I write, approval is pending for the use in patients with intermediate risk and it is quite possible that TAVR will replace the surgical approach in the next few years. In Europe, TAVR is used 60% of the time for the treatment of aortic stenosis.
A disruptive technology is one that displaces an established technology and shakes up the industry or a ground-breaking product that creates a completely new industry. Disruptive technologies are innovations often seen in the Tech world – like what Netflix did to Blockbuster or what the iPad did to personal computing or what the DVD did to the VHS.
The percutaneous approach to replacing the aortic valve is one such disruptive innovation.
For years, the only way to replace a stenotic aortic valve was to open the patient’s sternum while under general anesthesia, place him or her on cardiopulmonary bypass, open the aorta, excise out the old valve and sew in a new one. That demanded a team made up of the surgeon, anesthesiologist who acted also as the echocardiographer and a perfusionist.
For a TAVR, the cardiologist of surgeon punctures the femoral artery in the groin, introduces a wire with a ballon at the tip into the aorta and feeds the valve, in a collapsed state, all the way up into the aorta where the valve is, over this wire. The new valve is then inflated with the ballon. The new valve squishes the old valve against the wall of the aorta and in the process, takes it’s place. In most centers now, only a cardiologist or a surgeon performs the procedure!
If this becomes the dominant way of doing aortic valve replacements, tell me it’s not disruptive.
Years of accepted surgical practice will all of a sudden be made almost archaic. Why almost? Well, there will always be conditions where TAVR might not work and surgery is the only way (eg Endocarditis) or the patients may need other procedures. However it is possible that the majority of the estimated 1.5 million patients with aortic stenosis will undergo percutaneous and not surgical replacement.
Also, what this approach has done is spawn attempts to develop percutaneous approaches to replace or repair other heart valves. The Melody valve is already available to replace the pulmonary valve, a procedure often needed in children. There are also several percutaneous mitral valves in the works. The mitral clip is used to treat severe mitral regurgitation in the severely ill.
TAVR is not without it’s complications but it provides an alternative way of providing a needed service.
The history of cardiac care is marked with disruptive innovation. By the 1970’s, coronary artery bypass graft surgery (CABG) was the main way to treat coronary artery disease. Then Gruentzig developed percutaneous transluminal coronary angioplasty (PTCA) in the 1980’s and brought about an exciting new dimension in the treatment of coronary artery disease (CAD). (Gruentzig later migrated to the US and joined the faculty at Emory!) Then followed the development of stents. These developments were also very disruptive and dislodged the grip surgeons had on the treatment of coronary artery disease.
These very stents were what planted the idea of percutaneous valves in the mind of the Danish cardiologist, Henning Rud Andersen of Aarhus University in Jutland. Even though Cribber was the first to perform a percutaneous implantation in a human, Andersen was the first try this out in pigs.
And now we are seeing a tomorrow of percutaneous valves.
In 1995, Clayton M. Christensen coined the term, “Disruptive Innovation”, in his book “The Innovator’s Dilemma”. He defined it as:
“An innovation that creates a new market and value network and eventually disrupts an existing market and value network, displacing established market leaders and alliances.”
I argue that the TAVR is doing just that.
