Implantation of a percutaneous occluder device appears to be a viable option for reducing clinically important paravalvular regurgitation following TAVR, according to a case series published in the April 27, 2015, issue of JACC: Cardiovascular Interventions. The procedure is typically successful, although complications are common and the long-term benefit is clouded by high 1-year mortality. 

“Overall, our data suggest that percutaneous [paravalvular regurgitation] closure can be adopted in selected patients and performed by expert operators with acceptable long-term consequences,” write Francesco Saia, MD, PhD, of the University of Bologna (Bologna, Italy), and colleagues.

The investigators looked at 27 procedures to close clinically relevant paravalvular regurgitation in 24 patients (mean age 80.6 years; 75% men). The closure procedures, performed at 4 high-volume centers in Italy, Germany, Canada, and the United States, were done a mean of 316 days after TAVR with the balloon-expandable Sapien valve (Edwards Lifesciences; 54.2%) or the self-expanding CoreValve device (Medtronic; 45.8%).

Mean Society of Thoracic Surgeons score was 6.6%, and the vast majority of patients (91.7%) were in NYHA classes III or IV. In all, 87.5% were deemed inoperable. Valve postdilation was attempted in three-quarters of patients, and 1 patient was implanted with a second valve at the time of the index procedure. TEE was used in 20 procedures (74.1%) and intracardiac echocardiography in 1. Overall, 22 procedures were performed via a retrograde approach from the aorta and 5 with an antegrade transseptal approach. Local anesthesia was used in 26% of cases.

The main estimated causes of paravalvular regurgitation were:

• Incomplete adherence to the annulus: 50%
• Low implant: 25%
• Undersized valve (annulus/prosthesis mismatch): 16.7%
• High implant: 8.3%

High Procedural Success

Transcatheter closure was technically successful in 88.9% of cases, with final success (including multiple procedures in 2 patients) achieved in 91.7% of patients. Closure devices included the self-expanding Amplatzer Vascular Plugs 2, 3, or 4 in 20 procedures and the Amplatzer Muscular VSD occluder (both St. Jude Medical) in 4 procedures; closure using the Azur HydroCoil (Terumo) was attempted in 1 case but failed. In 6 instances, 2 devices were needed to obtain a good procedural result.

Average procedural duration was 86 minutes. There were 8 serious periprocedural complications (29.7%): 1 minor stroke without residual deficit, 1 pulmonary hemorrhage, 3 cases of stage 3 acute kidney injury, 2 instances of ventilator-associated pneumonia, and 1 valve embolization. No serious vascular complications were seen.

Echocardiography showed that the proportion of patients with grade 3 or 4 aortic regurgitation fell from about 97% before closure to 7.4% (all grade 3) afterward. Similarly, the number of patients in NYHA class III/IV dropped from 22 before closure to 7 at last follow-up.

Over an average follow-up of 12.3 months, 11 patients died. Three deaths were of cardiovascular origin, and 3 of the others were due to procedure-related causes (1 acute renal failure and 2 cases of ventilator-associated pneumonia with respiratory failure). Notably, none of the patients who died had postclosure aortic regurgitation above grade 2. Kaplan-Meier estimated survival was 83.3% at 1 month, 66.7% at 6 months, 61.5% at 1 year, and 55.4% at 2 years.

How to Reduce Complications

According to the authors, the study “confirms that percutaneous closure of [paravalvular regurgitation] is a complex and customized procedure.”

They offer several tips for minimizing complications:

• Use of contrast dye during the procedure should be discouraged to help avoid ventilator-associated pneumonia
• Choice of low-profile plugs compatible with smaller catheters lowers the risk of valve displacement during delivery
• Consideration should be given to avoiding general anesthesia and using a retrograde approach to cut down on ventilator-associated pneumonia, especially in severely compromised patients

Although the mortality rate was high, in most cases death was related to comorbidities, Dr. Saia and colleagues observe. Nonetheless, they add, because there was no control group, “it is difficult to estimate the impact of [the] procedures on the final outcome.”

‘Relatively High Threshold’ for Closure

Paravalvular closure “would appear to be the correct management, when carried out in centers experienced with [the procedure],” writes John D. Carroll, MD, of the University of Colorado School of Medicine (Aurora, CO), in an accompanying editorial. “[B]ut this study needs to be classified as observational, thought provoking, and hypothesis generating.”

The appropriateness of closure in a given case requires evaluation by a “heart team,” just as does TAVR itself, Ted Feldman, MD, of Evanston Hospital (Evanston, IL), told TCTMD in an email.

In fact, the paper suggests that experienced centers set “a relatively high threshold” for offering closure, Dr. Carroll notes, adding that “reasonable indications” include:

• An unremitting clinical problem
• Evidence of at least moderate paravalvular regurgitation
• Leaks that are technically approachable
• A risk/benefit balance that is clearly articulated and individualized for patient and family

From a procedural standpoint, Dr. Feldman said, having incomplete apposition or undersizing of the prosthetic valve as the source of regurgitation may make it more amenable to plugging, but overall the leak must be relatively focal whatever the mechanism. On the other hand, if the leak makes up a large arc of the annulus or a substantial part of the prosthesis skirt lies above or below the annulus, implantation of a closure device is unlikely to help.

The main technical challenges of the procedure, Dr. Feldman said, are finding the leak with a wire and crossing outside of the stent frame, and then getting a guide catheter to traverse the leak in between the stent frame and the compressed native leaflet.

Thus far, the durability of leak closure “seems excellent,” Dr. Feldman said, but because the patients are very sick, mortality remains high over the long term.

Ultimately, he predicted, advances in valve design are likely to minimize paravalvular regurgitation, making the closure procedure a temporary stopgap in the history of TAVR.

Rapid evolution in TAVR technology, notes Dr. Carroll, “makes it difficult to organize and conduct a prospective study [of paravalvular closure] with a control group in a timely fashion.”

Sources:
1. Saia F, Martinez C, Gafoor S, et al. Long-term outcomes of percutaneous paravalvular regurgitation closure after transcatheter aortic valve replacement: a multicenter experience. J Am Coll Cardiol Intv. 2015;8:681-688.

2. Carroll JD. Plugging paravalvular leaks after transcatheter aortic valve replacement: why and how [editorial]? J Am Coll Cardiol Intv. 2015;8:689-691.

Disclosures:

• Dr. Saia reports no relevant conflicts of interest.
• Dr. Carroll reports serving as a consultant to and receiving research support from Philips Healthcare.
• Dr. Feldman reports receiving research grants from and serving as a consultant to Boston Scientific and Edwards Lifesciences. 

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