Evolving strategies for the treatment of valvular heart disease: Preclinical and clinical pathways for percutaneous aortic valve replacement

First clinical trial of a self-expandable transcatheter heart valve in Japan in patients with symptomatic severe aortic stenosis

BACKGROUND

Transcatheter aortic valve implantation (TAVI) may be a viable solution for inoperable or high-risk patients with aortic stenosis (AS), providing the benefit of valve replacement without the associated risks of surgery.

METHODS AND RESULTS

The prospective, multicenter MDT-2111 Japan Trial evaluated the efficacy and safety of a self-expandable TAV in patients with severe AS. A total of 55 patients were enrolled (October 2011 to October 2012). Mean age was 82.5±5.5 years; 30.9% male, 100% NYHA III/IV, and STS 8.0±4.2%. At 6 months, 91.7% of the iliofemoral patients had met the primary endpoint (an improvement of at least 1 NYHA class and an effective orifice area >1.2 cm(2) for iliofemoral patients). For all patients, freedom from all-cause mortality at 6 months was 90.8%. At 30 days, the Kaplan-Meier rate of major vascular complications was 10.9%, the rate of permanent pacemaker implantation was 22.2% and the rate of major stroke was 3.7%. The incidences of paravalvular regurgitation for all implanted patients at 6 months were: 38.3% (none), 25.5% (trace), 31.9% (mild), 4.3% (moderate), and 0.0% (severe).

CONCLUSIONS

This is the first study to evaluate a self-expandable TAV in a Japanese patient population. The data show successful achievement of the study's primary objective and demonstrate the functional and anatomical effectiveness of the MDT-2111 TAV system.

PRE-MARKET CLINICAL EVALUATIONS OF INNOVATIVE HIGH-RISK MEDICAL DEVICES IN EUROPE

Objectives: High-quality clinical evidence is most often lacking when novel high-risk devices enter the European market. At the same time, a randomized controlled trial (RCT) is often initiated as a requirement for obtaining market access in the US. Should coverage in Europe be postponed until RCT data are available? We studied the premarket clinical evaluation of innovative high-risk medical devices in Europe compared with the US, and with medicines, where appropriate.

Methods: The literature and regulatory documents were checked. Representatives from industry, Competent Authorities, Notified Bodies, Ethics Committees, and HTA agencies were consulted. We also discuss patient safety and the transparency of information.

Results: In contrast to the US, there is no requirement in Europe to demonstrate the clinical efficacy of high-risk devices in the premarket phase. Patients in Europe can thus have earlier access to a potentially lifesaving device, but at the risk of insufficiently documented efficacy and safety. Variations in the stringency of clinical reviews, both at the level of Notified Bodies and Competent Authorities, do not guarantee patient safety. We tried to document the design of premarket trials in Europe and number of patients exposed, but failed as this information is not made public. Furthermore, the Helsinki Declaration is not followed with respect to the registration and publication of premarket trials.

Conclusions: For innovative high-risk devices, new EU legislation should require the premarket demonstration of clinical efficacy and safety, using an RCT if possible, and a transparent clinical review, preferably centralized.

The pre-clinical animal model in the translational research of interventional cardiology

Scientific discoveries for improvement of human health must be translated into practical applications. Such discoveries typically begin at "the bench" with basic research, then progress to the clinical level. In particular, in the field of interventional cardiology, percutaneous cardiovascular intervention has rapidly evolved from an experimental procedure to a therapeutic clinical setting. Pre-clinical studies using animal models play a very important role in the evaluation of efficacy and safety of new medical devices before their use in human clinical studies. This review provides an overview of the emerging role, results of pre-clinical studies and development, and evaluation of animal models for percutaneous cardiovascular intervention technologies for patients with symptomatic cardiovascular disease.