Patients Who Need Valve-in-Valve After TAVR See Poorer Outcomes

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In patients undergoing transcatheter aortic valve replacement (TAVR), the need for acute valve-in-valve therapy and the occurrence of embolization are both serious complications that carry added mortality risk. However, they may be avoided through careful procedural planning, according to a paper scheduled to be published online May 14, 2013, ahead of print in the Journal of the American College of Cardiology.

For the study, Raj R. Makkar, MD, of Cedars-Sinai Heart Institute (Los Angeles, CA), and colleagues culled data on 2,554 consecutive patients who underwent TAVR in the PARTNER randomized trial and nonrandomized registries, including both those considered inoperable and at high surgical risk. All received the Sapien valve (Edwards Lifesciences, Irvine, CA).

A total of 63 patients (2.47%) required valve-in-valve therapy and 26 (1.01%) experienced transcatheter valve embolization.

Valve-in-Valve Tied to Cardiovascular Mortality

Most valve-in-valve cases were immediate (88.9%), with a small minority occurring just after surgical closure of the left ventricular apex in transapical cases or within 4 months of the procedure. Nearly all cases (96.8%) resulted from post-procedural aortic regurgitation, of which 50.8% was transvalvular, 36.1% paravalvular, and 13.1% mixed. Two patients underwent valve-in-valve treatment due to unstable device position.

Of the cases arising from aortic regurgitation, 54.1% were due to leaflet malfunction and 41.0% to malpositioning; 5% were of unclear etiology.

At 30 days, patients who underwent valve-in-valve treatment were more likely to need a new pacemaker (11.2% vs. 5.4%; P = 0.05) and showed trends toward increased all-cause mortality, cardiovascular mortality, and rehospitalization.

By 1 year, all-cause mortality and cardiovascular mortality were higher after valve-in-valve treatment, though rehospitalization and stroke rates were statistically similar (table 1).

Table 1. Kaplan-Meier Estimates of 1-Year Outcomes

Valve-in-valve treatment independently predicted 1-year cardiovascular mortality (HR 1.86; 95% CI 1.03-3.38; P = 0.041) but not all-cause mortality (HR 1.43; 95% CI 0.88-2.33; P = 0.15). Landmark analysis indicated that the greatest disparity in cardiovascular mortality was seen beyond 30 days.

Embolization Also Raises Mortality Risk

Transcatheter valve embolization, meanwhile, was most likely to occur immediately after valve deployment (76.9%), with most of the remaining instances within an hour of implantation (19.2%) and 1 case (3.8%) related to cardiopulmonary resuscitation at 7 hours post-procedure. Initial direction of embolization was evenly split between aortic and ventricular.

More than half (53.8%) of embolization cases were managed percutaneously while the rest required conversion to open heart surgery. Embolization was more common when the index TAVR was performed using the transfemoral vs. transapical approach.

The cause of embolization was only identified for 73% of cases. Most commonly, embolization arose from malpositioning (19%), complex anatomy (15%), and pacing failure (11%).

Patients with embolization were more likely to need hemodynamic support and conversion to open heart surgery, and their cases involved higher contrast use and fluoroscopy and procedure times.

At 1 year, the complication was associated with increased all-cause death and cardiovascular death as well as trends toward more major stroke and MI (table 2).

Table 2. Kaplan-Meier Estimates of 1-Year Outcomes

Embolization predicted 1-year all-cause mortality (HR 2.68; 95% CI 1.34-5.36; P = 0.0055). Landmark analysis supported this association but did not indicate any relationship between embolization and cardiovascular mortality.

“The most important findings from this study are that both [valve-in-valve] and [transcatheter valve embolization] carry a heavy burden of complication and [that] all cases had probable underlying causes. . . . [T]hese causes were either anatomical or technical, and many could be considered preventable through appropriate procedural planning,” Dr. Makkar and colleagues conclude.

Not All Valve-in-Valve the Same

In a telephone interview with TCTMD, Peter C. Block, MD, of Emory University School of Medicine (Atlanta, GA), emphasized that the valve-in-valve procedures described here differ substantially from those performed to address the chronic issues of surgically implanted valve prostheses.

“This is a more acute situation. It’s usually due to rather severe paravalvular leakage or aortic regurgitation, and therefore it’s usually in the same setting,” he explained.

Similarly, Philippe Généreux, MD, of Columbia University Medical Center (New York, NY), characterized valve-in-valve procedures within surgical prostheses as somewhat elective. In the case of TAVR, valve-in-valve is done specifically to correct problems arising from the procedure.

An Ounce of Prevention

Given the reasons why valve-in-valve is done, it is clear that preprocedure planning would be beneficial, Drs. Block and Généreux agreed. They cited efforts including better valve sizing and evaluation of calcification in the aortic annulus.

The learning curve does appear to matter, Dr. Généreux said. “In PARTNER IIb, we tremendously decreased the amount of valve embolization. First of all, the sites were more experienced. Secondly, we planned better, mainly by using CT scans to size the valve. And the [Sapien XT] device is better. It’s more stable.”

At the root of the problem is paravalvular leak, Dr. Block explained.

Growing experience has taught operators how to treat such leaks without resorting to valve-in-valve, he said. When post-dilation does not work, valve-in-valve is a “simple solution because [it] allows the first valve to be expanded to its maximum expansion rather than being able to recoil,” he added.

The procedure makes sense if needed, Dr. Block commented, “but obviously a second valve is never as good as a single one.”

After valve-in-valve, Dr. Généreux noted, “there’s nothing really to do [to decrease subsequent risk]. You need to do everything you can to avoid it and have a successful procedure with 1 valve.”

Newer Devices Better

According to the paper, the Sapien device is more prone to needing valve-in-valve than the Sapien XT; the former has leaflets with a default open configuration while the latter has leaflets in a partially closed configuration even when open. “Similarly, the self-expanding Medtronic CoreValve device [Minneapolis, MN] comprises a long stent frame that covers the native leaflets completely, preventing the possibility of leaflet overhang [thereby reducing transvalvular aortic regurgitation],” the researchers report.

“Clearly,” said Dr. Block, “looking forward the whole issue of paravalvular leak . . . is going to be the major issue that all of the new-generation valves will have to face.” He expressed hope that better design would come close to eliminating the need for valve-in-valve.

“I think device innovation will be such that, in the near future [these issues] will be nearly nonexistent,” Dr. Généreux concluded, adding that in some ways, the procedure is still very primitive. Not only are the new devices more stable but future devices may enable recapture, he said.

Note: Study coauthors Martin B. Leon, MD, and Susheel K. Kodali, MD, both of Columbia University Medical Center, are faculty members of the Cardiovascular Research Foundation, which owns and operates TCTMD.

 

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Source:
Makkar RR, Jilaihawi H, Chakravarty T, et al. Determinants and outcomes of acute transcatheter valve-in-valve therapy or embolization: A study of multiple valve implants in the US PARTNER trial. J Am Coll Cardiol. 2013;Epub ahead of print.

 

 

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