As a “minimalist” approach to transcatheter aortic valve replacement – known as MA-TAVR – gains in popularity at high-volume centers, questions persist about the surgeon’s learning curve. A small series of MA-TAVR cases at Emory University in Atlanta has shown that the leaning curve may be like the TAVR approach itself: minimal.
Dr. Hanna Jensen and her associates reported on 151 consecutive patients who had MA-TAVR in the October issue of the Journal of Thoracic and Cardiovascular Surgery (J Thorac Cardiovasc Surg. 2015. doi: 10.1016/j.jtcvs.2015.07.078). They previously reported their findings at the annual meeting of the American Association for Thoracic Surgery in April in Seattle.
This study builds on an Emory study last year that reported the minimalist approach to TAVR cost about $10,000 less per patient than the standard transfemoral approach (JACC Cardiovasc Interv. 2014;7:898-904).
The operation the study authors evaluated is performed in the catheterization laboratory rather than the operating room, as in traditional TAVR. Both approaches use a femoral approach, but where traditional TAVR requires general anesthesia and transesophageal echocardiography (TEE), MA-TAVR uses local anesthesia, minimal conscious sedation, and transthoracic echocardiography (TTE).
The study authors acknowledged concerns that TTE may underestimate the severity of paravalvular leak after the procedure when compared with TEE. Their protocol relies on preoperative TTE and CT scans, or three-dimensional TEE if the case warrants it, to ensure optimal sizing of the transcatheter valve before the operation. “If any concerns arise, our threshold is low to perform intraoperative balloon-sizing,” Dr. Jensen and her coauthors said. They also use TTE, along with a root-angiogram after valve deployment, and invasively measure the aortic regurgitation index before and after deployment.
Most study patients were high-risk surgical candidates with a median Society of Thoracic Surgeons Predicted Risk of Mortality (STS PROM) score of 10%. The overall major stroke rate was 3.3%, while major vascular complications occurred in 3% of patients and the greater-than-mild paravalvular leak rate was 7%.
The study retrospectively evaluated 151 consecutive patients who were divided into three groups at different time points: May 2012 to January 2013, February to August 2013, and September 2013 to July 2014. Complications were similar among all three groups, but the third group had shorter hospital stays and less time in the intensive care unit (ICU).
The first group received only the first-generation SAPIEN valve system; use of the second-generation SAPIEN XT valve increased in latter two groups. The SAPIEN XT valve is available in 23, 26, or 29 mm, but the 29-mm size was not available in the first-generation SAPIEN implant.
A subgroup analysis looked at patients who were discharged within 48 hours of the operation or more than 48 hours afterward. The early-discharge patients had lower STS PROM scores (8.3% vs. 10.3%) and lower rates of diabetes (31% vs. 49%). They also had less need for postoperative pacemakers and less frequent rehospitalization. “This implies that in selected MA-TAVR patients early discharge is feasible and safe, but larger studies are required to identify the optimal profile of patients who can be sent home within the first two postoperative days,” Dr. Jensen and her colleagues said.
Early in the MA-TAVR protocol all patients were sent to the ICU. As the care team gained more experience with the procedure, the protocol changed to send all patients to a regular telemetry floor after surgery unless they had vascular issues or potential need for a pacemaker. The decreasing need for ICU “was the only indication of an institutional learning curve that was discovered, and demonstrated improved resource utilization over time,” the investigators said.
They encouraged other centers to pursue MA-TAVR. “As experience grows, we believe that this procedure can be done with less or no ICU support leading to a shorter hospital stay and improved resource utilization,” Dr. Jensen and her coauthors concluded. They called for further studies to determine the characteristics that make a patient most suitable for a short-admission MA-TAVR procedure.
Study coauthors Dr. Vasilis Babaliaros, Dr. Vinod Thourani, Amy Simone, and Patricia Keegan are research consultants with Edwards Lifesciences. The rest of the authors had no disclosures.