TAVI - Transcatheter Aortic Valve Implantation

 TAVI/TAVR procedure is an attractive alternative for elderly patients as:

• Lower mortality as compared to surgical Aortic Valve Replacement.
• Less invasive with no open heart surgery needed.
• Patients can be made to walk up the very same day.
• As no major surgery is needed, there is no surgical scar.
• No general anaesthesia is needed and it can be done with mild sedation or just local anaesthesia.
• Due to the early mobilisation of the patient, there is less hospital stay, including ICU stay.

SAVR is mainly done in patients who are young, i.e., younger than 65 years of age with no other major comorbidities.

Who is a Good Candidate for TAVI/TAVR Procedure?

Any candidate who has been diagnosed with severe aortic stenosis (i.e., aortic valve narrowing) and is more than 65 years of age is a candidate for TAVI/TAVR procedure. Occasionally, if a younger patient has many comorbidities and may have a high risk for open heart surgery, then they may also be a candidate for TAVI/TAVR procedure.

Prior to TAVI/TAVR, routine blood tests are done. ECG, echocardiogram, and usually a coronary angiogram are performed prior to the procedure.

Multidisciplinary Team Approach in Patient Evaluation

Once severe aortic valve narrowing is diagnosed, a heart team discussion is done which involves the cardiologist, a cardiac surgeon, and the patient and their relatives. Both the pros and cons of the TAVI/TAVR procedure and surgical AVR are discussed and put forth for the patient to choose which procedure they would like to proceed with.

Types of TAVI/TAVR Valves, Selection Criteria & Their Durability

There are mainly two types of TAVI/TAVR valves: Balloon-expanding and self-expanding ones. Balloon-expanding valves are mounted on the balloon itself and opened at the valve level, whereas the self-expanding valves are expanded at the valve level by self-opening with an inherent valve opening mechanism. Various valve companies have their valves available in India. Based on the patient characteristics and the CT scan measurements, the best valve suitable for the patient will be discussed by the cardiologists. Usually, the valves last for around 10-15 years, but it depends on the patient and inherent valve characteristics.

Step-by-Step Description of the TAVI/TAVR Procedure

• Written informed consent is taken from the patient, and the patient is admitted a day prior.
• Patient is shifted to the cath lab.
• Ultrasound-guided puncture of the femoral arteries (groin arteries) is done.
• Pre-sutures are kept at the arteries.
• A temporary pacing wire may be inserted for rapid pacing in some cases.
• Sheath is inserted through the artery and from there the valve is inserted into the body.
• The valve is placed across the native aortic valve under fluoroscopy.
• Thereafter, the sheath is removed and the pre-sutures are closed off.

Usually, the TAVI/TAVR procedure is done through the transfemoral access, but in some cases where this access is not feasible, alternative arteries like subclavian (arms), carotid, or aortic (neck) arteries may be used. In very occasional cases, transapical i.e., direct insertion through the heart may be performed.

Post procedure, the patient is shifted to the ICU for overnight monitoring of the heart rate as the procedure is bound to cause heart blocks.
There is very little recovery time needed post an uncomplicated procedure. Patients can walk the same day and can be discharged home the next day.

How long will it take to recover fully after TAVI/TAVR Procedure?
Usually some rest is advised at home for a few days post procedure, but after a couple of weeks, patients can resume their daily activities.

Are there any restrictions or activities I should avoid during recovery?
Post TAVI/TAVR procedure you should not drive a car for a few weeks as per your country's regulations. Groin care is needed for a few days post procedure, so you should avoid squatting down for a few days post procedure.

Short-term and long-term follow-up protocols
Blood thinners are to be continued post procedure. Else no other specific treatment is needed post procedure. Regular echocardiogram screens are done for these patients. Firstly a pre discharge echo is done to see the valve parameters and then usually they are done yearly or earlier if there are any new symptoms.

Following main complications can occur during or post the procedure:

• Complete Heart Block - During the valve deployment, with stretching of the bundle of His, there can be a 10% chance of pacemaker need and higher if pre existing conduction abnormalities.
• Annular Injury - This occurs when the valve is deployed, especially if there is significant calcium at the annular level. This injury can lead to pericardial tamponade and potentially death. This may need immediate draining of the fluid from the pericardial cavity and referral to surgeon for immediate surgical repair.
• Vascular Complications - Groin related bleeding and failure of pre sutures may need covered stents or surgical repair as this may also be life threatening.
• Stroke or Paralysis - Can occur in around 2% of the cases of TAVI/TAVR Procedure. This may be minor or can be disabling or occasionally life threatening.
• Death due to the procedure is around 1% or less.

There are promising outcomes for the short and medium term post TAVI/TAVR procedure. With rates better than surgical AVR. The success rates are getting better due to better valves and also the gaining expertise of the cardiologists.

Long term success rate of TAVI/TAVR Procedure
Long term success of TAVI/TAVR procedure is also good, though it may be slightly difficult to analyse as patients are usually elderly and may have many other comorbidities to make things difficult to evaluate. To put it in simple words, TAVI patients as they are old with many other diseases, may die from other causes as well.

Comparison of outcomes between TAVI/TAVR Procedure and SAVR
In the short term, definitely the TAVI valves do better over the surgical AVR as it is less invasive and a procedure with fewer complications. Recent long term data for longevity of the procedure show similar rates of valve degeneration for both TAVI valves and bioprosthetic surgical valves.

Sometimes the CT characteristics or the patient per se may not be suitable for the TAVI/TAVR procedure. For eg. the access may be an issue or occasionally the annulus may be such that it may be a very high risk for a TAVI/TAVR procedure. Though these characteristics which may preclude the TAVI procedure are few.

Cost-effectiveness and Accessibility Issues
This is the main limitation in countries like India where the procedure expense is done by the patients themselves and is not presently state funded in most states. As a surgical AVR is usually a cheaper procedure presently, many patients may opt for the same even if they are better candidates for TAVI/TAVR procedure.