UK TAVI Registry Supports Use of Subclavian Access When Transfemoral Not Possible

The subclavian route is a good second choice for TAVR access after transfemoral, while the transapical and direct aortic approaches yield worse survival, according to registry data published online September 2, 2015, ahead of print in the American Journal of Cardiology. 

“Subclavian access was the only nonfemoral approach for which survival was not significantly different to [transfemoral], and may represent the safest nonfemoral access route for [TAVR],” write Daniel J. Blackman, MD, of Leeds General Infirmary (Leeds, England), and colleagues.

The researchers examined data from the UK TAVI registry on 3,962 patients who underwent TAVR from 2007 through 2012.

Among the 4 access routes studied, in-hospital, 30-day, and 1-year mortality were lowest with transfemoral vs other types of access (table 1).

Individual comparison of the subclavian and femoral groups showed no difference for in-hospital mortality (P = .69), while the transapical and direct aortic groups had higher mortality compared with transfemoral (P < .0001 and P < .02, respectively).

Additionally, in Kaplan-Meier analysis, there was no difference in estimated 1-year survival rates between the transfemoral and subclavian groups (84.6% vs 80.5; P = .27), but transfemoral survival was higher than for either transapical (74.7%) or direct aortic approaches (75.2%; both P < .0001), which were similar to each other.

A propensity-matched analysis confirmed that a subclavian approach was noninferior to the transfemoral route (P = .86).

A Cox proportional hazard model analyzing mortality out to 2 years also found no difference between the subclavian and transfemoral groups (HR 1.22; 95% CI 0.88-1.70) but increased risk for transapical (HR 1.74; 95% CI 1.43-2.11) and direct aortic (HR 1.55; 95% CI 1.13-2.14) approaches compared with transfemoral access.

Validation for Subclavian

The study authors observe that because patients undergoing transapical access “invariably have a worse risk profile [than those receiving the default transfemoral approach], it is unclear to what extent worse outcomes relate to the patient rather than to the procedure itself. Nonetheless, they point out, renal replacement therapy, a known predictor of increased mortality, was more frequently required with [tranasapical access].” Additionally, they say, some studies have shown greater levels of cardiac biomarker release after transapical TAVR, as well as less improvement in LVEF and apical wall motion abnormalities and scarring that “might be a source of arrhythmia and adverse late events.”

Furthermore, Dr. Blackman and colleagues note that the lack of a survival difference between the transfemoral and subclavian cohorts is consistent with data from the European PRAGMATIC registry as well as the high-risk cohort of the CoreValve US Pivotal Trial, which showed numerically lower 30-day mortality with subclavian vs direct aortic access.

Ted Feldman, MD, of Evanston Hospital (Evanston, IL), told TCTMD that the results regarding higher mortality with direct access and transapical access are not surprising, while the subclavian results reflect “the great power of a registry like this one.”

Although the study authors provide little insight into why the subclavian results are so similar to those with transfemoral access, Dr. Feldman said patients requiring subclavian access “probably don’t have the same level of peripheral vascular disease burden that [those requiring] apical and transaortic do.” Importantly, he said, the data validate that subclavian access can be done safely and is a good alternative to transfemoral.

Alternative Access Better Than No TAVR

However, Dr. Feldman cautioned that the results should not be interpreted as suggesting that direct aortic and transapical access have no role or that patients requiring this type of access are not good TAVR candidates.

“What is crystal clear is that compared to not treating them, alternative access still provides a huge advantage,” he noted, adding that “we don’t quite know how much of an advantage compared to standard surgery, but… from an ease of recovery and rehab standpoint, it’s night and day. The study reinforces the idea of ‘femoral first’ for TAVR, but the fact that a quarter of patients in this registry needed alternative access also emphasizes that we have learned not to push too far with transfemoral.”

In a telephone interview with TCTMD, Philippe Généreux, MD, of Hôpital du Sacré-Coeur de Montréal (Montréal, Canada), said that the results “are similar to what we see in the real world in terms of subclavian outcomes mirroring transfemoral somewhat. Direct aortic and transapical access, to me, are still surgery and not less invasive techniques.”

Given the higher-risk status of patients who do not qualify for transfemoral access, techniques that involve surgical cutdowns combined with the lower survival rates should give clinicians some pause, especially with regard to frail elderly patients, he added.

“The data are certainly interesting and they suggest that we should consider transfemoral first, subclavian second, direct aortic third, and transapical last, as dictated by anatomical suitability,” Dr. Généreux noted. “That being said, these data are now somewhat outdated. With the availability of newer devices and lower profiles, I’m not sure how often those last 3 options will be needed.” In fact, he predicted that over the next few years, as many as 85% of patients will be suitable candidates for transfemoral TAVR with newer devices.

Source: 
Fröhlich GM, Baxter PD, Malkin CJ, et al. Comparative survival after trans-apical, direct aortic, and subclavian transcatheter aortic valve implantation. Am J Cardiol. 2015;Epub ahead of print. 

Disclosures:

• Dr. Blackman reports serving as a consultant and proctor for Boston Scientific and Medtronic. 
• Dr. Feldman reports receiving consulting fees and grants from Abbott Vascular, Boston Scientific, and Edwards Lifesciences.
• Dr. Généreux reports receiving speaker’s fees from Edwards Lifesciences.