The prevalence of calcific aortic stenosis is growing due to the increase in degenerative valve disease, which affects 2.5% of people aged over 65; it is estimated that at least 32000 individuals in Portugal have the condition.1

The first-line treatment is surgical aortic valve replacement (SAVR).2,3 Outcomes are adversely affected by the presence of certain comorbidities, and so transcatheter aortic valve implantation (TAVI) was developed for patients considered unsuitable for surgery.4

The 2012 guidelines published jointly by the European Society of Cardiology (ESC) and the European Association of Cardio-Thoracic Surgery (EACTS) assign a class I or IIa recommendation for TAVI according to clinical indications.3

National data for Portugal indicate an annual rate of TAVI of seven procedures per million population, a third of the rate in Spain and the UK and a seventh of the European Union average of 45 implantations.5,6

The PARTNER trial, the only randomized study to date, reported a reduction in overall mortality in inoperable patients (cohort B) from 51% with optimal medical therapy to 31% with TAVI at one-year follow-up.7

Use of TAVI was further consolidated following publication of the second arm of the trial (cohort A), in which the percutaneous technique, via a transfemoral or transaortic approach, was compared with SAVR. Outcomes for TAVI tended to be better in terms of 30-day mortality (3.4% in the TAVI group vs. 6.5% in the SAVR group, p=0.07), but there was no significant difference in two-year mortality (33.9% TAVI vs. 35% SAVR),8 both groups presenting significant functional improvement at two-year follow-up.8,9

Numerous registries have been published suggesting that the efficacy and safety of TAVI are generally good when performed outside of trials. Piazza et al.14 published one of the first in 2008, reporting 30-day mortality of 8.0% and a combined major event rate – death, myocardial infarction and stroke – of 9.3%. Four years later, in the UK TAVI registry of 870 patients, 30-day mortality was 7.1%, but rose to 26.3% at two-year follow-up. The landmark FRANCE 2 registry, a mandatory official registry, with 3195 patients, covering all types of valve and approaches, including subclavian and transaortic, reports 30-day and one-year mortality of 9.7% and 24%, respectively.10

The only registry directly comparing TAVI with SAVR is an Italian one analyzing 618 patients that used three methods of statistical adjustment, including propensity scores. The annual major event rate based on the Valve Academic Research Consortium (VARC) criteria was 11.8%, with no significant differences between the two techniques in occurrence of death, stroke or myocardial infarction.11

The impact on quality of life has been the focus of much interest since the evidence consistently shows marked improvement from one month after TAVI.9,12

In general, the technique is used in patients who are judged inoperable or at high surgical risk due to older age, comorbidities, female gender, higher functional class, emergency operation, left ventricular dysfunction, pulmonary hypertension, coexisting coronary artery disease, or previous cardiac surgery, including for bioprosthetic valve failure.3,13

It should be stressed that implementation of TAVI programs has generally involved highly motivated teams with proctoring in the first 5–15 cases.14

Notwithstanding the good results obtained, certain aspects give rise to concern. Various periprocedural complications can require particular attention.15,16 Periprosthetic regurgitation, mitral regurgitation and need for pacing appear to adversely affect long-term outcomes.10,17–19 Medium-term non-cardiovascular mortality is high, reaching 59% in a study by Rodés-Cabau et al. of 339 patients followed for 42 months, which suggests that patient selection needs to be improved.20

SAVR can be a costly procedure in high-risk patients, with an additional cost of 2400 euros in hospital charges for each 1% increase in the Society of Thoracic Surgeons score,21 but it is not known whether TAVI can reduce these costs. In the US, the additional cost of TAVI per life-year gained is around 40 000 euros compared with standard care in inoperable patients.21,22 The PARTNER trial recently demonstrated that in 80% of cases the costs of SAVR and TAVI do not differ significantly at one year of follow-up.

It was against this background that the ESC/EACTS guidelines on the management of valvular heart disease were issued, which demonstrate the importance of this sophisticated and revolutionary technique in patients considered unsuitable for SAVR.23

The Working Group recognizes the importance of TAVI programs being run by formally established multidisciplinary teams in centers of excellence with on-site cardiac surgery. Each team should include at least a cardiac surgeon, an interventional cardiologist, an anesthesiologist and a cardiologist experienced in echocardiography. The procedures should be performed in a hybrid operating room, a cardiac catheterization laboratory equipped as an operating room, or an operating room equipped with an imaging system of appropriate quality. Extracorporeal circulation should be available if required.

With regard to the clinical indications in the guidelines (Table 1), we should bear in mind the constraints of the International Monetary Fund financial bailout in Portugal and the publications suggesting that TAVI should only be performed in carefully selected patients in centers with a minimum annual volume of 50 procedures, in order to keep additional costs at an acceptable level and to maintain proficiency.15

It is therefore recommended that TAVI programs should preferentially treat inoperable patients with a class I recommendation.3

Patients with a class IIa recommendation should be considered for TAVI if:

• •

  the risk-benefit ratio is favorable in terms of quality of life as assessed by the heart team;

• •

  the center considers that the indication is compatible with the experience of the team and the predicted annual volume of procedures15;

• •

  the procedure is performed under the scope of investigational studies or registries.

The consensus is that the use of TAVI should be rigorously monitored, preferably through a national multicenter registry using the current VARC criteria to ensure quality and transparency.24,25 It is recommended that all patients be followed for seven years and that nationwide studies be undertaken in Portugal to assess the costs of the technique.

The Working Group hopes that this document will be useful to health professionals, institutions, departments and decision-making bodies dealing with this important and rapidly developing treatment.

TAVI is the only effective treatment for patients with aortic stenosis who are considered unsuitable for surgery.

The technique should be performed in centers of excellence that have a formally established and trained multidisciplinary heart team, treat a minimum of 50 cases a year, have appropriate technical conditions, and keep a prospective registry for monitoring purposes.

The authors have no conflict of interest to declare.