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Sutureless AVR an option for higher-risk patients

Key clinical point: Sutureless aortic valves have the potential to achieve shorter procedure times and benefit increased-risk patients with aortic stenosis.

Major finding: Thirty-day mortality of patients who received the Enable aortic valve was 1.6%, and late mortality was 3.2%. No deaths were valve related.

Data source: Sixty-three patients with aortic stenosis who had Enable bioprosthetic valve implantation between August 2012 and October 2014 at McGill University Health Center.

Disclosures: Lead author Dr. Benoit de Varennes is a consultant for Medtronic and a trainer for the Enable device. The other authors had no relationships to disclose.

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Sutureless option to conventional AVR

One of the key advantages that advocates of sutureless valves point to is shorter bypass times than sutured valves, but in his invited commentary Dr. Thomas G. Gleason of the University of Pittsburgh questioned this rationale based on the results Dr. de Varennes and colleagues reported (J. Thorac. Cardiovasc. Surg. 2016;151:743-744). The cardiac bypass times they observed “are not appreciably different from those reported in larger series of conventional aortic valve replacement,” Dr. Gleason said.

Dr. Gleason suggested that “market forces” might be driving the push into sutureless aortic valve replacement. “The attraction, particularly to consumers, of the ministernotomy (and thus things that might facilitate it) is both cosmetic and the perception that it is less invasive,” he said. “These attractions notwithstanding, it has been difficult to demonstrate that ministernotomy or minithoracotomy yield better primary outcomes (e.g., mortality, stroke, or major complication rates) or even quality of life indicators, particularly when measured beyond the perioperative period.”

Dr. Thomas G. Gleason

He alluded to the “elephant in the room” with regard to sutureless aortic valve technologies: their cost and unknown durability compared with conventional sutured bioprostheses.

“As health care costs continue to rise and large populations of patients are either underinsured or see rationed care, trimming direct costs may be a more relevant concern for the modern era than trimming cross-clamp time,” he said. Analyses have not yet evaluated the increased costs of sutureless valves in terms of shortened hospital stays or lower morbidity, particularly in the moderate-risk population with aortic stenosis, he said.

“Moving forward, there is little doubt that the current value of the sutureless valve will be dictated by the market, but in the end it will be measured by the long-term outcomes of the ‘minimally invaded,’” Dr. Gleason said.

Dr. Gleason had no financial relationships to disclose.


 

FROM THE JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY

References

The first North American experience with a sutureless bioprosthetic aortic valve that has been available in Europe since 2005 and is well suited for minimally invasive surgery has underscored the utility of the device as an alternative to conventional aortic valve replacement (AVR) in higher-risk patients, investigators from McGill University Health Center in Montreal reported in the March issue of the Journal of Thoracic and Cardiovascular Surgery (2016;151:735-742).

The investigators, led by Dr. Benoir de Varennes, reported on their experience implanting the Enable valve (Medtronic, Minneapolis) in 63 patients between August 2012 and October 2014. “The enable bioprosthesis is an acceptable alternative to conventional aortic valve replacement in higher-risk patients,” Dr. de Varennes and colleagues said. “The early hemodynamic performance seems favorable.” Their findings were first presented at the 95th annual meeting of the American Association for Thoracic Surgery in April 2015 in Seattle. A video of the presentation is available.

The Enable valve has been the subject of four European studies with 429 patients. It received its CE Mark in Europe in 2009, but is not yet commercially approved in the United States.

In the McGill study, one patient died within 30 days of receiving the valve and two died after 30 days, but none of the deaths were valve related. Four patients (6.3%) required revision during the implantation operation, and one patient required reoperation for early migration. Peak and mean gradients after surgery were 17 mm Hg and 9 mm Hg, respectively. Three patients had reported complications: Two (3.1%) required a pacemaker and one (1.6%) had a heart attack. Mean follow-up was 10 months.

Patient ages ranged from 57 to 89 years, with an average age of 80. Before surgery, all patients had calcific aortic stenosis, 43 (68%) had some degree of associated aortic regurgitation, and 46 (73%) were in New York Heart Association (NYHA) class III or IV. At the last follow-up after surgery, 61 patients (97%) were in NYHA class I.

The investigators implanted the valve through a full sternotomy or a partial upper sternotomy into the fourth intercostal space, and they used perioperative transesophageal echocardiography in all patients. They performed high-transverse aortotomy and completely excised the native valve.

The average cross-clamp time for the 30 patients who had isolated AVR was 44 minutes and 77 minutes for the 33 patients who had combined procedures. Dr. de Varennes and colleagues acknowledged the cross-clamp time for isolated AVR is “similar” to European series but “not very different” from recent reports on sutured AVR (J. Thorac. Cardiovasc. Surg. 2015;149:451-460). “This may be explained partly by the learning period of all three surgeons and the aggressive debridement of the annulus in all cases,” they said. “We think that, as further experience is gained, the clamp time will be further reduced, and this will benefit mostly higher-risk patients or those requiring concomitant procedures.”

They noted that some patients received the Enable prosthesis because of “hostile” aortas with extensive root calcification.

Dr. de Varennes disclosed he is a consultant for Medtronic and a proctor for Enable training. The coauthors had no relationships to disclose.

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