Up until around five years ago if you suffered a heart condition called aortic stenosis (where one of the heart valves does not open properly and blood flow is reduced), or a related problem called ‘regurgitation’ (where a heart valve ‘leaks’), your only option was open heart surgery, a procedure referred to as SAVR or Surgical Aortic Valve Replacement.
SAVR involves an open heart procedure, that is the chest must be opened to access the heart and the patient must be connected to a cardiopulmonary bypass machine. As this is a major surgical procedure, many patients needing this surgery are classified as high-risk due to age or other conditions or complications and are not able to undergo the procedure.
TAVR – Transcatheter Aortic Valve Replacement – was introduced to give these higher risk patients an alternative. As it was a brand-new procedure where the risks are largely unknown compared to the conventional procedure, only those patients who were in this high-risk group were given the option of the new approach. At the time TAVR was to an extent viewed as an ‘inferior’ option to SAVR, but one that could potentially save many lives of people classified as ‘unfit for surgery’, which in fact it has.
This assumption of the superiority of the open heart approach has been challenged by the findings of a study, called the SURTAVI trial, which looked at outcomes in the US in 1,746 patients undergoing the TAVR and SAVR procedures. The trial looked at how the patients were faring two years after surgery and found that both approaches were very similar in outcome, with TAVR technically slightly more successful, but not to a statistically significant degree.
Patients in the trial had an average age of nearly 80 and were largely similar in terms of age, gender and other conditions such as frailty and disability. Data from echocardiograms of all patients indicated that the TAVR valves generally worked better than the SAVR valves, although a rare complication called paravalvular leakage was more common in those undergoing TAVR than SAVR. Those undergoing the SAVR on the other hand needed more blood transfusions and were more prone to stroke, acute kidney damage and atrial fibrillation at the 30-day mark than TAVR patients.
The trial team is now looking at a second study to assess TAVR in low risk patients.
Developments in the TAVR procedure are now focused on the replacement valve itself, improving its sealing ability within the existing (failing) heart valve, reducing the size so that it can be manoeuvred through narrower arteries, and allowing it to be more precisely positioned into the existing valve.
Despite the results of the trial it is unlikely that the TAVR procedure will completely replace the open heart approach – given that many of the patients on this particular trial were of advanced age there is unlikely to be very much data on the longer term effectiveness of the TAVR procedure, something that is relevant in assessing the suitability of TAVR in younger, lower risk patients.
For more information on the TAVR procedure, please review this section on the HeartHealth website. For more information on the TAVR and SAVR procedures, please speak to your HeartHealth specialist.