TAVI, or transcatheter aortic valve implantation, is an invasive method of treating aortic stenosis. When is TAVI used? How is the procedure performed and what are its complications?

TAVIortranscatheter aortic valve implantationis an invasive method of treating aortic stenosis (aortic valve stenosis). The method of treating aortic stenosis depends on many factors, including the severity of the defect, symptoms, and comorbidities. There are two management strategies: conservative with periodic check-ups and echocardiography, and invasive. Two methods are available for invasive treatment: surgical valve replacement and transcatheter aortic valve implantation - TAVI.

Aortic stenosis, or aortic stenosis, is a heart defect in which it is difficult for blood to flow out of the heart's left ventricle, so the heart has to make more effort to deliver the same volume of blood to the vessels. The cause of this condition may be degeneration, rheumatic disease, or a congenital bicuspid valve. Aortic stenosis is the third most common heart disease and is estimated to affect 5% of people over the age of 75. Symptoms may not be present for many years, and when they do occur most often are chest pains, palpitations, shortness of breath and fainting.

The primary diagnostic method is echocardiography. The indications for invasive treatment are a decrease in the ejection fraction of the heart (below 50%) and the so-called tight stenosis of the valve, the criteria of which are: valve area below 1.0 cm2, aortic gradient above 40 mmHg, flow velocity through the valve above 4 m / s. In addition, invasive treatment is undertaken in the presence of symptoms, the presence of advanced coronary disease, and an abnormal exercise test result. Therapeutic options include: surgical valve replacement, which is the basic method of therapy in advanced cases, and TAVI - a relatively new method, carried out in Poland since 2009.

In the case of high operational risk, the method with proven effectiveness is TAVI.

These procedures should only be performed in hospitals with a cardiac surgery department. The assessment of the team is the basis for qualification for the procedureexperts - members of the so-called heart team (cardiac surgeon, interventional cardiologist, conservative cardiologist). They assess the patient's individual risk and the technical possibilities of the procedure. TAVI is typically performed in patients with severe, symptomatic aortic stenosis who, according to the heart team, do not qualify for conventional surgery because of severe comorbidities and high surgical risk, which are assessed using the mn scales. in. EuroSCORE or STS. Currently, TAVI is not performed in patients with moderate operational risk.

TAVI: contraindications

There are 4 groups of contraindications to TAVI: Absolute contraindications:

  • no team of experts and a cardiac surgery department at the site of the procedure;
  • no confirmation by the team of experts of the usefulness of TAVI as an alternative to cardiac surgery;

Clinical contraindications:

  • severe disease of another valve causing symptoms and only treatable by surgery
  • little chance of improving the quality of life due to comorbidities;
  • very short life expectancy;

Anatomical contraindications:

  • aortic annulus too small or too large (29 mm);
  • thrombus in the left ventricle visualized on echocardiography;
  • active endocarditis;
  • anomalies of the coronary arteries and the risk of their closure during the procedure;
  • plaques with mobile clots in the ascending aorta or in the arch;
  • due to the place of access: wrong vessel size, calcification, tortuosity;

Relative contraindications:

  • two-leaf or non-calcified valve;
  • untreated coronary artery disease requiring interventional treatment;
  • unstable patient condition;
  • left ventricular ejection fraction<20%;

The TAVI procedure is performed in a hybrid room which is a combination of a hemodynamics laboratory and an operating room. Thanks to this, in the event of serious complications, it happens in 1-2% of procedures, it is possible to perform cardiac surgery without the need to transport the patient to the operating room. TAVI is performed under local or general anesthesia, access is via the femoral artery, rarely the heart tip or the subclavian artery. The procedure begins with puncturing both femoral arteries and a femoral or jugular vein (a vein to temporarily stimulate the heart). Guides and catheters are inserted through the arteries to the initial section of the aorta and the left ventricle of the heart, their position is controlled by means of a scopy (X-ray image duringreal) - after administration of a contrast agent and without it, and with the help of transesophageal echocardiography. After precise measurements, a balloon is used to widen the narrowed valve, and then the artificial valve is inserted into the right place, placed and "packed" on the catheter and deposited. The final element of the procedure is the effect control.

TAVI: complications

The main complications associated with the procedure are:

  • paravalvular regurgitation (12-25%), mostly trace and most clinically insignificant;
  • need to use a new pacemaker (up to 7-40%);
  • vascular complications (up to 20%);
  • stroke (approx. 1-5%);
  • aortic dissection, cardiac tamponade (approx. 0.5-3%)
  • conduction disturbances - atrioventricular blocks

The annual survival rate after TAVI is 60-80% and depends mainly on the severity of comorbidities. Most patients experience a significant improvement in their he alth and quality of life. It should be remembered that after implantation of an artificial mechanical valve, patients must take anticoagulants for the rest of their lives and monitor the INR. Transcatheter aortic valve implantation is one of the important treatments for the most common valve disease, aortic stenosis. It is an essential alternative for patients who, due to their general condition, do not qualify for cardiac surgery. The basis for qualification for TAVI is an individual assessment of the heart team, i.e. operational risk or contraindications to TAVI. The procedure is not free from complications, but most often it improves the patient's well-being.

Bibliography: 1. Guidelines for the management of valvular heart disease for 2012 Joint Working Group of the European Society of Cardiology (ESC) for the management of valvular heart disease and the European Society of Cardiac Surgeons and Thoracic Surgeons (EACTS) 2. Interna Szczeklika 2016/20173. http://www.osibialystok.pl/dok/mat_konf_gdansk/TAVI-P.Falkowska.pdf

About the authorBow. Maciej GrymuzaA graduate of the Faculty of Medicine at the Medical University of K. Marcinkowski in Poznań. He graduated from university with an over good result. Currently, he is a doctor in the field of cardiology and a doctoral student. He is particularly interested in invasive cardiology and implantable devices (stimulators).

Category:

Cardiology