CHICAGO – Whether to perform transcatheter aortic valve implantation in a 57-year-old patient with a severely calcified aortic homograft was the subject of a case report presented at Heart Valve Summit 2012.
"In our center, even though we do a huge number of TAVIs [transcatheter aortic valve implantations], we still believe TAVI should be left for the older patients and those with a restricted life expectancy, because the long-term results are not known," said Dr. Michael Borger, assistant director of the Leipzig (Germany) Heart Center.
The patient in this case was a 57 year-old woman who presented with increased shortness of breath and was found to have NYHA II-III heart failure. At age 40, she had received a homograft aortic root replacement for destructive endocarditis.
Her ejection fraction and left ventricular dimensions were preserved, her AV gradient was 86/52 mm Hg, and her effective orifice area (EOA) was 0.6 cm2. She had no other risk factors and was taking no medications. A coronary angiogram showed a severely calcified homograft and isolated proximal stenosis of the right coronary artery.
Dr. Borger discussed two options: redo root replacement surgery with a bypass to the right coronary artery or a transcatheter aortic valve replacement (TAVR) with a PCI to the right coronary artery.
The decision was to perform conventional surgery. "The patient underwent a redo Bentall operation with a mechanical valve, as well as a RIMA (right internal mammary artery) to RCA (right coronary artery) bypass. She did very well postoperatively without any complications," he said.
Aortic root replacements with aortic homografts are not without risk, and the literature shows relatively high mortality for homograft reoperations. Reoperation after stentless AVR also has been performed, but it often requires replacement of the aortic root and is associated with increased mortality (Ann. Thorac. Surg. 2007;84:737-43).
"Most of those [stentless] operations are difficult because of the inability to get a good plane of cleavage between the stentless valve and the native aortic root," said Dr. Borger. "The large majority of those patients end up leaving the OR with a full root replacement."
Dr. Borger’s fellow panelist, Dr. Michael Reardon, agreed. "I was a real fan of the Toronto SPV valve, and ... I’ve taken a couple out," said Dr. Reardon, professor and vice chair of the Methodist DeBakey Heart and Vascular Center in Houston. "They all end up in root replacements. By the time you’re finished you end up having these shards of tissue ... and porcine tissue incites a huge dermoplastic reaction. ... I personally found it very difficult."
Dr. Borger noted, "In Leipzig we have put in a large number of Toronto roots and, knock on wood, have not reoperated on one of them yet. However, they have not yet reached the period whereby you expect to observe structural valve dysfunction."
A study of valve-related events after aortic root replacement with cryopreserved aortic homografts examined risk after placement of a homograft and found that a heavily calcified homograft at the time of reoperation was a significant predictor of death (Ann. Thorac. Surg. 2005;79:1491-5).
"I’m not saying that TAVI is not an option for all young patients," said Dr. Borger. "If you’ve got a young patient who is at very high risk for conventional surgery with lots of comorbidities, whose life expectancy is 5 years or less, then sure, do a TAVI. But for this particular patient, if she survives the operation, you’re going to put her back on an almost normal survival curve."
Dr. Borger disclosed consultant fees and honoraria from Medtronic, St. Jude Medical, and Edwards Lifesciences.