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Since the beginning of TAVI, indications have shifted from compassionate to high risk patients. What are in 2011 the good candidates for TAVI ?

It is true than over the last 9 years, the indications have been cautiously extended from companionate cases (I-REVIVE trial, RECAST trial) to high surgical risk patients and patients with contra-indication to surgery from 2005 in all registries, according to the Societies of Cardiology and cardiac Surgery's recommendations. However, from 2010, the indications have a trend to expand to less severely sick patients. In Europe, the minimal logistic Euroscore has dropped from > 20% to > 15%. The notion of "patient frailty" has been launched. As a matter of fact, any patient for whom a consensus of the Heart Team is obtained for TAVI is a good indication. Some trials in Europe are on the way including low Euroscore patients.

You talked about an average 5% of failures across the different experiences. Do you consider immediate valve malposition as a technical failure? How often did you have to manage immediate valve malposition? How can this complication be managed?

Actually, the rate of success is closer to 98% to date, whatever the model of valve used. Immediate valve embolization and malposition are part of the failures. With the Edwards valve, malposition has become very infrequent with the progresses in imaging, valve sizing and with the learning curve. The valve can be implanted a little too high or too low, with the risk of compromising the coronary ostia in the first case or having a significant paravalvular regurgitation or a permanent AV block in the other. Improvement of the delivery system, careful selection of the best X ray projection, and experience have almost solved the problem. Malposition can request a valve-in-valve procedure. Valve embolization is now exceptional, more often to the aorta than to the left ventricle. Withdrawal and setting of the Edwards valve in the descending aorta with the balloon inflated distally is a solution in the majority of cases (the valve can be stented open if necessary). Embolization in the left ventricle requires urgent surgical extraction, either through the LV wall or through the aorta under cardio-pulmonary bypass.

Did you ever had to perform immediate or early additional ballooning after the initial procedure? If yes, in which cases did this happen?

Repeat balloon inflation after delivery has been proposed in case of severe paravalvular regurgitation in order to insure a optimal stent opening. There is not too much benefit to re-balloon the valve if the full quantity of contrast (17ml for the 23mm and 22 ml for the 26mm valve) has been actually administered during delivery, more particularly if the balloon has been kept inflated 5 sec, to decrease the frame recoil. Oversizing the balloon during repeat inflation is useless, since the pet cuff covering the stent externally is not extensible. Preventing this issue by careful selection of the valve size according to the annulus size is crucial. Measurement of the annulus, whatever the method used (TTE, TEE, CT) remains however imprecise. In case of any doubt about the actual annulus size, the best way is for us to size the annulus at the time of valve predilatation by a combination of balloon inflation and aortography (dynamic sizing). This is highly recommended in all borderline cases.

You mentioned that your routine practice is to discharge patients after 24h in ICU and a post-TAVI stay of 3 days. What kind of particular follow-up do you recommend when the ICU and the hospital stay were uneventful?

Such short stays in intensive care unit and in-hospital are our politics with the use of the Edwards XT valve under local anesthesia/sedation. Longer stays of 2 days in ICU and 5 to 6 days in hospital were the rule after Edwards SAPIEN implantation and cut-down of the femoral artery. If everything's fine, clinical follow-up is obtained at 3-month, 6-month, one year and every years for all patients, including TTE and clinical exam.

Some results that you presented show a 10% mortality rate at 30 days. What are the main causes of early death?

Early mortality is in general associated with severe cardiac or vascular complications requiring emergent surgery, or severe device related complication. It can also be associated with severely compromised clinical status at the time of TAVI (terminal renal failure, pulmonary insufuciency, severe CAD, etc..). Prevention of complication by optimal screening, more experience and technological improvements are the key for a reduction in early mortality, which can actually be observed in the most recent trials.

Are there any reports of mid-term to late migration of the valve?

To my knowledge, there was no report of late device migration and in our experience, no case was observed.

The technique and the devices used for TAVI have become similar to those used in stenting procedures. Is there any information about the possibility of restenosis after TAVI, like it is seen with bare stents and even covered stents?

No, the problem is totally different. No endothelial proliferation can be feared after valve implantation as in coronary stenting. The risk would rather be valvular deterioration as observed in surgical biologic valves, but so far, no case has been reported after 3 or 4 years of follow-up.

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Watch the related video THV Implantation: Trans-Femoral Approach - Edwards XT