Italian Registry Cautions Against TAVR in Low-Risk Patients


Despite the eagerness on the part of some physicians and institutions to offer TAVR to lower-risk patients with aortic stenosis, observational data suggest that surgery is still the best option for this population.  

Implications. Italian Registry Cautions Against TAVR in Low-Risk Patients

The results, from an Italian registry study, contrast with recently-published randomized data that are favorable to TAVR in similar populations and “suggest that, at this stage, expanding the indications of TAVI toward lower-risk patients may not be justified,” write Stefano Rosato, MSc (Istituto Superiore di Sanità, Rome, Italy), and colleagues.

In the study published online May 6, 2016, ahead of print in Circulation: Cardiovascular Interventions, Rosato and colleagues looked at 355 propensity-matched pairs of patients from the Italian OBSERVANT registry who had EuroScore II < 4%; 15.6% underwent TAVR and 84.0% underwent surgical AVR (SAVR). The majority of TAVR procedures (91.1%) were performed femorally and included both the self-expanding CoreValve (Medtronic) and the balloon-expandable SAPIEN XT (Edwards Lifesciences) valves.

Surgery Offers Survival Advantage at 3 Years

Rates of mortality and stroke at 30 days did not differ between the two procedures. However, for the primary outcome of 3-year survival and the secondary outcome of freedom from MACCE, surgery patients did markedly better than TAVR patients.

Table. Italian Registry Cautions Against TAVR in Low-Risk Patients

Patients undergoing TAVR had a relative 70% increase in the risk of dying at 3 years (HR 1.70; 95% CI 1.22-2.37).

Additionally, patients who underwent surgery had more cardiogenic shock, severe bleeding, and acute kidney injury, while those who underwent TAVR had more cardiac tamponade, permanent pacemaker implantation, major vascular damage, mild-to-severe paravalvular regurgitation, and moderate-to-severe paravalvular regurgitation. Regurgitation and pacemaker complications, the study authors note, are of particular concern in low-risk patients. Even with ongoing improvements in TAVR technology, such complications “may have negative prognostic implications in low-risk patients in view of their longer expectancy of life,” they add.

The study authors note that while it is unclear from their study why TAVR was chosen in such low-risk patients, it likely was the result of “institutional policies of choosing TAVI instead of SAVR even if this indication drift was not supported by clear evidence of any benefit in low-risk patients.” Another likely scenario is that some lower-risk elderly patients may have requested the minimally-invasive procedure over surgery.

OBSERVANT Contradicts NOTION

Just last year at the EuroPCR meeting in Paris, researchers presented results from the first randomized trial of TAVR vs SAVR in lower-risk patients. The trial, known as NOTION, included patients with a life expectancy of at least 1 year and average EuroScore II of about 2%. Whereas low-risk OBSERVANT patients saw a clear advantage with surgery, NOTION patients showed similarly favorable outcomes for the primary composite endpoint of death from any cause, stroke, or MI at 1 year.

Rosato and colleagues say the discordant findings between OBSERVANT and NOTION may be due to the fact that the latter trial excluded many patients (randomizing only 18% of those screened), and was likely underpowered.

In an editorial accompanying the OBSERVANT paper, Michael N. Young, MD, and Sammy Elmariah, MD (Massachusetts General Hospital, Boston, MA), point out that mortality after TAVR was twice as high in OBSERVANT vs NOTION, which is surprising given the low-risk nature of the study population. They say one explanation may be that because of the device specified in the trial, no patients in NOTION underwent transapical TAVR, which carries higher mortality risks. Further digging into OBSERVANT to look at transapical procedures and attendant mortality rates may shed more light on these differences, they add.

“At the end of the day, the central question remains whether TAVR should be offered as an option for low-risk patients who do not have a contraindication to surgery,” Young and Elmariah say. “Although TAVR is an exciting technology that has already saved countless lives, we must not lose sight of the tremendous merit and favorable clinical outcomes provided by SAVR.”


Disclosures:

  • Rosato, Young, and Elmariah report no relevant conflicts of interest.
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    Sources
    • Rosato S, Santini F, Barbanti M, et al. Transcatheter aortic valve implantation compared with surgical aortic valve replacement in low-risk patients. Circ Cardiovasc Interv. 2016;9:e003326.

    • Young MN, Elmariah S. Transcatheter aortic valve replacement in low-risk patients within the observational study of effectiveness of SAVR-TAVI procedures for severe aortic stenosis treatment study: observing the unobserved. Circ Cardiovasc Interv. 2016;9:e003830.

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