Surgical Options May Shape Interventional Cardiology
Emerging technologies in grafts and valve repair are hot topics.
Arterial grafts for weak blood flow, along with new technologies and devices, may present solid solutions for the future of interventional cardiology and will further improve the periprocedural capabilities of cardiologists.
In Tuesday’s session titled “Breakthroughs in Cardiac Surgery: What the Interventionalist Needs to Know,” Joseph F. Sabik, MD, from the Department of Thoracic and Cardiovascular Surgery at the Cleveland Clinic, Cleveland, Ohio, reviewed the potential role of aortic valve replacement and edge-to-edge mitral repair as routine procedures. Additionally, Sabik presented data on 15-year patency of internal mammary artery (IMA) and other arterial grafts.
Sustained patency
With some exceptions, IMA and most other arterial grafts exhibit long-term patency out to 10 and 15 years, according to Sabik. Risk factors for IMA occlusion include lesser proximal stenosis, time after graft (especially in non-left coronary artery disease), right arterial IMA, smoking, female gender and diabetes.
At 15-year follow-up, patency remained at 98% for patients with 100% stenosis who received IMA for LAD, with similar results for patients with 50% stenosis (92% patency), Sabik said. However, patency for patients with 100% stenosis undergoing IMA for non-LAD was 100% compared to 76% for patients with 50% non-LAD.
The differences in patency can probably be ascribed to competitive flow and/or technical error during grafting, Sabik said.
In nearly all cases, IMA shows superior patency compared to saphenous vein grafts (SVGs), which tend to fail at a rate of 5% every year due to atherosclerosis, Sabik said. In right coronary artery disease with low-to-moderate stenosis, Sabik noted, SVGs tend to survive a little better than IMAs.
“You probably want to avoid using an IMA in a right coronary artery, but if you do, you probably want stenosis over 70% or you’re going to have a lot of early failure,” Sabik said.
Aortic valve replacement
Aortic valve replacement (AVR), has been performed successfully since 1950. Advances in technologies and refinements in technique have helped lower the mortality rate to 3.5% and the stroke rate to 1.5%. Durability at 20 years is between 77% and 92%, according to Allan S. Stewart, MD, director of the Aortic Surgery Program at Columbia University Medical Center.
Currently, AVR is an open-heart procedure, but devices that would allow transcatheter valve replacement are in development, Stewart said.
Investigation is ongoing on the plausibility of transfemoral and transapical delivery methods, Stewart said, but several factors need to be addressed before the procedure is added to the regular armamentarium of interventional cardiologists. The gross anatomy of the human heart presents major obstacles, as the position of the ostia, both pre- and post-implant, is unpredictable, Stewart said. Patients with either a large or small annulus present unique problems, and crossing the valve may also be complicated if calcification extends to the aortic root, Stewart added.
Mitral repair
Another breakthrough that may shape the future of interventional cardiology is edge-to-edge mitral repair. First performed in 1991, edge-to-edge mitral repair has become a valuable tool for correcting anterior and posterior lesions, according to Francesco Maisano, MD, of San Raffaele University, Milan, Italy.
At his own institution, Maisano said that about 25% of cases are currently treated with edge-to-edge mitral repair with the Alfieri procedure first described in 2001 in the Journal of Thoracic and Cardiovascular Surgery.
So long as some important surgical rules are followed, edge-to-edge mitral repair is a “technically simple and highly reproducible procedure,” Maisano said.