• Interventional Techniques & Devices
• Cardiology Clinical Trials
• Valvular Disease

Transcatheter aortic valve implantation (TAVI) is a treatment option for patients with aortic valve stenosis who are either high risk or not operative candidates for conventional surgical aortic valve replacement (SAVR). Transfemoral TAVI requires delivery of the valve system through the iliofemoral vasculature and is limited by peripheral vascular disease (PVD) and small vessel caliber. Transapical TAVI is somewhat more invasive than the transfemoral approach but can be utilized in patients with severe PVD or smaller leg vessels. The role of TAVI in patients who are operable candidates or at lower surgical risk has not been studied. Leif Thuesen, MD, Aarhus University Hospital, Aarhus, Denmark, presented the Prospective, Randomized Trial of Transapical Transcatheter Aortic Valve Implantation versus Surgical Aortic Valve Replacement in Operable Elderly Patients with Aortic Stenosis (STACCATO) trial. The objective of STACCATO was to evaluate the safety and efficacy of transapical TAVI in operable, lower-risk patients.

A total of 72 patients were randomized to transapical TAVI (n=34) or SAVR (n=36). Two patients were excluded after randomization. Eligibility criteria included valvular aortic stenosis (valve area <1.0 cm²), age ≥70 years (later amended to age ≥75 years), patients who were treatable by either transapical TAVI or SAVR, and expected survival >1 year following successful treatment. The primary endpoint was the composite of 30-day all-cause mortality, major stroke, and/or renal failure that required dialysis.

The study design called for inclusion of 200 patients. After inclusion of 11 patients, the study was put on hold due to 3 potentially serious adverse events in the transapical TAVI group. After inclusion and exclusion criteria were modified (increased age limit to 75 years and exclusion for previous heart surgery), the study was resumed.

After randomization of 70 patients, the independent data safety monitoring board recommended study termination due to an excess number of adverse events in the transapical TAVI group. Primary endpoint events occurred in 5 patients in the transapical TAVI group and 1 patient in the SAVR group within 3 months (p=0.07; Table 1).

After treatment, the mean aortic valve area increased from baseline in the transapical TAVI group from 0.66 cm² to 1.4 cm² (p<0.0001) and in the SAVR group from 0.71 cm² to 1.3 cm² (p <0.0001). Baseline peak aortic gradient was higher in the transapical TAVI group compared with the SAVR group. Both groups had lower gradients after treatment (p<0.0001), with a lower gradient in the transapical TAVI group than in the SAVR group (p=0.07). Paravalvular leakage after treatment was more frequent with transapical TAVI than SAVR (p<0.001; Table 2). The NYHA class was significantly improved from baseline in both the transapical TAVI (p=0.01) and SAVR (p=0.001) groups.

The study was limited by the inclusion of only two enrolling centers with some experience in performing transapical TAVI. Furthermore, preoperative use of multislice CT was not utilized to optimize valve sizing and positioning relative to the left main. Since the trial was terminated early, the estimates of the risks and benefits may be less precise due to a smaller sample size than had been planned.

Prof. Thuesen concluded that in its present phase of development, transapical TAVI appears to be inferior to SAVR in low-risk, operable, elderly patients. This study highlights the importance of patient selection, noninvasive preprocedural assessment, and the current indications for the procedure; TAVI should be used in nonoperable or surgically very high-risk patients. The role of transapical TAVI requires further investigation to determine what clinical role it may have.

• © 2011 MD Conference Express