Mayo Clinic Assesses Its TAVI Learning Curve

December 21, 2011—Findings from a study that aimed to assess the learning curve for the implantation of a percutaneous aortic valve via the transfemoral route were published by Oluseun O. Alli, MD, et al and are available online ahead of print in the Journal of the American College of Cardiology: Cardiovascular Interventions.

The background of the study is that transcatheter aortic valve implantation (TAVI) is a fundamentally new procedure for the treatment of aortic valve stenosis and that the number of cases needed to gain proficiency with concomitant ease and familiarity (ie, the learning curve) with the procedure is unknown.

The data show increasing proficiency with evidence of plateau after the first 30 cases. Although more studies are needed to confirm these findings, the investigators concluded that experience accumulated during 44 transfemoral TAVI procedures led to significant decreases in procedural times, radiation, and contrast volumes.

In this study, the investigators performed a retrospective analysis of the first 44 consecutive patients who underwent TAVI at the Mayo Clinic in Rochester, Minnesota between November 2008 and May 2011 as part of the PARTNER (Placement of Aortic Transcatheter Valve) trial. PARTNER is the pivotal study of the Edwards Sapien transcatheter aortic valve, which received US Food and Drug Administration approval on November 2, 2011.

As detailed in the Journal of the American College of Cardiology: Cardiovascular Interventions, the median age of the patients was 83 years (interquartile range, 77–87 years) and a median Society of Thoracic Surgery risk score of 9.6. Preprocedural assessment of the aortic valve revealed a mean gradient of 53.5 mm Hg, mean aortic valve area of 0.7 mm², and a median ejection fraction of 59.5%.

Patients were divided into tertiles based on sequence. From tertiles 1 to 2 to 3, there were significant decreases in median contrast volume (from 180 to 160 to 130 mL; P = .003), valvuloplasty to valve deployment time (from 12 to 11.6 to 7 min; P < .001), and fluoroscopy times (from 26.1 to 17.2 and 14.3 min; P < .001). Significant decreases in radiation doses were also seen across the three tertiles (P < .001). The 30-day mortality rate for the entire cohort was 11%, reported the investigators.