Transcarotid Bests Aortic/Apical for Alternative TAVR Access: TVT Registry

CHICAGO, IL—For patients who need TAVR but are not suitable candidates for a transfemoral procedure, transcarotid access is a better bet than the apical or aortic route, according to data from the STS/ACC TVT Registry.

Keith Allen, MD (St. Luke’s Mid America Heart Institute, Kansas City, MO), who presented the propensity-matched analysis during a late-breaking clinical science session at TVT 2019, told attendees that at least in this nonrandomized analysis, there appears to be a survival benefit with transcarotid.

Transfemoral TAVR is far and away the most common procedure, and the safest. In the earliest days of the procedure, a transapical approach was used for patients with vascular anatomy precluding a transfemoral approach, but in recent years a range of alternate access sites have been pioneered for alternate access.

“The need for nonfemoral access during TAVR will continue to decrease as transcatheter heart valve size and deliverability are optimized,” Allen said here. “However, as the pool of patients that require alternative access decreases, the complexity of those patients will increase, requiring the heart team to have comparative data between alternate access routes. Unfortunately, that comparative data is currently limited.”

Staying Out of the Thorax

To help fill that void, Allen and colleagues queried the more than 100,000 TAVR cases involving the Sapien 3 biosprosthetic device (Edwards Lifesciences) entered into the TVT Registry between 2015 and 2018, looking specifically at the 2,606 patients who had transapical/transaortic (TA/TAo) access and the 492 treated using a transcarotid approach. Of note, TA/TAo cases have declined steadily since 2015, most notably in the last year and a half, while transcarotid procedures have sharply increased.

“In fact,” said Allen, “sites using transcarotid access with Sapien 3 for TAVR cases have doubled in the last year and there are now 90 sites in the US doing these procedures.”

Alternate access options that mimic the results of transfemoral TAVR, don’t violate the thoracic cavity, provide the straightest path to the aortic valve, and are simple and cost effective are clearly desirable. Keith Allen

All patients undergoing alternate-access TAVR were high risk, Allen noted, pointing to mean STS scores of 8 in both the transcarotid and TA/TAo groups. Transcarotid-access patients had slightly higher body mass index overall than those treated via the TA/TAo routes and were more likely to have undergone prior PCI, but they were otherwise very similar.

Investigators then used 23 baseline covariates to propensity match the two groups 1:2, yielding 457 transcarotid patients from 88 sites and 914 TA/TAo patients treated at 270 sites.

Device success was similar between groups at approximately 97%, but other procedural and outcome differences were marked. Procedure times were slightly shorter for the transcarotid access patients, but fluoroscopy time was longer. There was no significant difference in the number of conversions to surgery, which was “surprisingly quite low,” but the numbers showed a trend in favor of transcarotid, Allen said.

Strikingly, 30-day mortality was significantly lower in the transcarotid group, as were the rates of new-onset atrial fibrillation, all-cause hospital readmissions, and—importantly—stroke. Quality of life on the Kansas City Cardiomyopathy Questionnaire (KCCQ) also showed greater gains among the transcarotid-TAVR patients.

“We all worry about stroke,” Allen said. “Heavens! You can’t access the carotid and work in the carotid without everybody stroking! But in fact, stroke rates were 4% in the carotid group and 3% in the TA/TAo group, [which was] not significantly different.”

Procedural and 30-Day Clinical Outcomes

 

A host of other 30-day outcomes including new dialysis, new pacemaker, and major vascular complications, while not statistically significantly different, numerically went in favor of transcarotid.

“A really underappreciated aspect of TAVR is: where do patients go, particularly those who get alternative access, when they leave the hospital?” Allen continued. “And across the board, patients that had transcarotid access required far less patient care following discharge. In fact, almost 82% of the transcarotid patients were discharged home. This is particularly important when you look at the impact of transfer DRGs on hospital TAVR revenue.”

Acknowledging the limitations of registry-based analyses, including the observational nature of the study as well as missing data points that might help drive best practice with the carotid approach, Allen nevertheless concluded that the findings overwhelmingly support transcarotid access.

“Alternate access options that mimic the results of transfemoral TAVR, don’t violate the thoracic cavity, provide the straightest path to the aortic valve, and are simple and cost effective are clearly desirable,” he stressed. “Transcarotid access appears to fit that description.”

Still needed, however, are additional analyses comparing transcarotid to subclavian and transcaval techniques, he added. “Particularly with recent reports of a stroke risk of 6% with both balloon-expandable and self-expanding valves when delivered transaxillary. We need to determine what is the preferred alternate access and I think this data supports transcarotid as the preferred access choice.”

Anything but Transthoracic

Speaking with TCTMD, Bernard Prendergast, MD (St. Thomas’ Hospital, London, England), called the analysis “very important.”

“This tells us once more that transapical and transaortic—in other words, intra-transthoracic approaches for TAVI—are really a thing of the past,” he said. This is particularly true as the feasibility of transfemoral procedures increases. “I think ‘anything but transthoracic’ is where we need to be in the future,” Prendergast commented.

Similar opinions were voiced during the discussion that followed Allen’s presentation, with session co-moderator Martin Leon, MD (NewYork-Presbyterian/Columbia University Irving Medical Center, New York, NY), pointing to an upcoming meta-analysis in the European Heart Journal. This is an 8,000-patient meta-analysis combining the seven randomized TAVR trials across all three risk categories.

“Clearly if you stay out of the thorax, extra-thoracic TAVR is very different from intrathoracic TAVR by either the transapical or transaortic approach,” Leon said. The next urgent question, however, is whether transcarotid is as good, or better, than the “preferred” nontransfemoral approach, which is subclavian axillary “at most sites,” he added.

Allen, in response, said that he’s hoping to have those data by TCT 2019.

Michael Reardon, MD (Houston Methodist DeBakey Heart and Vascular Center, TX), then posed the question of whether it’s time to compared transcarotid to transfemoral in the TVT Registry. Allen was cool on this idea. “There is an inherent difference in patients that have transfemoral,” he stressed. “If you have PAD that’s so occlusive that you cannot get anything up the groin, those patients behave differently. . . . I really don’t think these patient populations are apples to apples.”

Reardon added that he’d “love” to do a randomized trial between axillary and carotid access but feels there are very few patients who can’t be treated via a transcarotid approach.

“It’s amazing: I would encourage all of you to look at your next TAVI patients, whether they are transfemoral or not. Most of your CTs will scan up through the lower cervical neck and if you just look at the carotid arteries . . . the carotid arteries seem to be protected. Oftentimes patients that have a lot of PAD or aortoiliac disease, they also have significant subclavian disease and they may have high cervical carotid disease, up by the bifurcation. But that’s not where you’re accessing patients: you’re accessing them low in the neck. I would argue that the carotid artery teleologically is a very large, robust, rubbery artery—it’s a really nice artery to work on compared often to what we see with subclavian or axillary,” he explained.

Allen added that his hospital actually did their first 100 cases using intraoperative electroencephalography, but stopped when they realized they’d not once changed their procedure plans based on neuroimaging.

Leon said he was “surprised” to see that transcarotid procedures are already being done at so many sites, which raises issues of operator proficiency and volumes. “Of those 90 sites, how many are actually doing this procedure with enough frequency to achieve the best results?”

In fact, said Allen, just 15 sites performed over 50% of the cases. “So there are a lot of one-offs, a lot of places that do just one or two transcarotids. In our analysis, the learning curve appears to be somewhere between five and 10 cases,” he said. “If you’re a program doing 50 TAVR cases, and you’re maybe doing one alternate-access case a year, that brings into question where those case should be done.”