Aortic stenosis is narrowing of the main valve , impeding blood flow circulation from the heart to the aorta.
More than 1.5 million of people live in US with aortic stenosis, and the current, standard treatment is surgical replacement of the valve, through open heart surgery.
The risks of open heart surgery precludes this treatment for about 30% of patients, who are deemed to be ” high risk candidates” for surgery, due to age, or preexisting conditions: advanced kidney failure, emphysema, home Oxygen dependency, severe heart failure, advanced malignancy. The risk of surgery and recovery is so high, that outweighs the benefit .
These patients, with severe Aortic stenosis, (AS), without surgery, have a high mortality within 2 years of diagnosis and poor quality of life ; their prognosis is worse than most advanced, metastatic cancers.
TAVR, or – trans catheter aortic valve replacement, became lately a great alternative of surgery.
TAVR means replacing the valve, minimally invasive, without open heart , with a catheter inserted through the groin which delivers and deploys the valve; almost like an angiogram and stent placement. There is no surgical risk and the procedure carries much less recovery time, ( 1-2 days) vs (5-6 days). The procedure is performed by a cardiologist, in the cardiac catheterization laboratory, lasting a couple of hours.
Image of valves used for TAVR
TAVR was approved by FDA in 2011 for very high risk patients- considered inoperable, in 2014, for high risk patients and in 2017 for medium risk patients.
Ongoing trials are looking at the benefits of TAVR vs Surgical valve replacement in the largest population not studied yet: low risk patients with Aortic stenosis. The question is simple: durability of these valves with the new procedure which eliminates major risk associated with open heart surgery and cardiac bypass.
History of TAVR discovery
Dr Henning Rud Andersen conceived the idea of TAVR in 1988, looking for an alternative of surgical valve replacement in high risk patients, with a high mortality within 2 years of diagnosis. In May 1989 the first successful pig implant of nonsurgical valve occurred
the VIP pig, with nonsurgical valve implant
The first successful TAVR implant occurred in France, by Dr Alain Cribier, April 2002
Where do we stand with medical evidence about TAVR
There are 3 FDA approved valves for TAVR
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First and older version, Edwards Sapien XT, (the deployment is done over a balloon- “balloon expandable”)
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Newest Edwards Sapien 3, (the deployment is done over a balloon- “balloon expandable”)
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Medronic CoreValve, – self-expandable, no balloon necessary
“Partner trial ” compared TAVR vs surgical replacement of aortic valve in different patient populations:
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In very high risk, nonoperable patients, TAVR was superior to medical therapy, improving significantly survival.
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In high risk patients, TAVR was similar in decreasing mortality compared to surgical treatment.
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In high risk patients ,the newest valve, ” Corevalve”, was superior in decreasing mortality than surgery .
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In intermediate risk patients, TAVR is similar or even superior than surgery, in decreasing mortality.
Where do we go from here ?
Ongoing trials with Medtronic Corevalve are looking into the benefits of noninvasive vs surgical therapy in low risk patients. If durability of this valve shows promise, we may be looking at a shift of standard surgical therapy to noninvasive , over the next 10 years.
Many hospitals are adding TAVR, to their program.
Its appropriate for patients and referring physicians to inquire about TAVR options, and be educated about the benefits in special populations.
Being beneficial in very high risk and intermediate risk categories, does not make it an appropriate option for low risk surgical patients, at least at present.
There is a shift in the cardiology approach in treating Aortic Stenosis: we call it a “heart team” approach. The decision for TAVR vs surgical therapy is based on the ” patient risk “- high, intermediate or low, and involves a team of imaging cardiologist, interventional cardiologist and cardio-vascular surgeon. Well designed protocols and screening tests are reviewed by the team, using a score system to calculate each patient individual risk of surgery and candidacy for TAVR.