Clinical endpoints in transcatheter aortic valve implantation: a call to ARC for standardised definitions

In-hospital complications after transcatheter aortic valve implantation revisited according to the Valve Academic Research Consortium definitions

OBJECTIVES

To determine the occurrence of in-hospital complications after transcatheter aortic valve implantation (TAVI) according to the Valve Academic Research Consortium (VARC) criteria in addition to the length of stay (LOS).

BACKGROUND

The absence of uniformity in endpoint definitions challenges the comparison between previously reported major adverse cerebro- and cardiovascular event rates after TAVI. To address this, in 2009, the VARC was established aiming to provide standardized endpoint definitions for TAVI clinical trials.

METHODS

Between November 2005 and September 2010, we prospectively enrolled 150 consecutive patients who underwent TAVI with the Medtronic CoreValve System in our institution. Complications, prosthetic valve associated endpoints, and therapy-specific endpoints were defined according to the definitions provided by the VARC.

RESULTS

The mean age (±SD) was 81 (±7) years and 55% were female. Thirty-day or in-hospital mortality was 11%, and the 30-day combined safety endpoint was 22%. Seventy-six patients (51%) had ≥1 cardiovascular and/or noncardiovascular complication of whom 16 also underwent a new permanent pacemaker implantation (PPI). In the 74 patients with uneventful TAVI, 12 patients (8%) underwent PPI. TAVI was truly uneventful in 62 patients (41%). Bleeding complications were observed most frequently (31%), followed by acute kidney injury (18%), vascular complications (16%), and stroke/TIA (11%). The median LOS in patients with a complicated and a truly uncomplicated TAVI was 14.0 (8.0-20.5) and 8.0 (7.0-10.8) days, respectively (P < 0.001).

CONCLUSION

TAVI was associated with ≥1 cardiovascular and/or noncardiovascular event in 51% of the patients; new PPI was needed in another 8%, and TAVI was truly uncomplicated in 41%. Complications and need for new PPI significantly prolonged LOS.

Standardized endpoint definitions for transcatheter aortic valve implantation clinical trials: a consensus report from the Valve Academic Research Consortium

OBJECTIVES

To propose standardized consensus definitions for important clinical endpoints in transcatheter aortic valve implantation (TAVI), investigations in an effort to improve the quality of clinical research and to enable meaningful comparisons between clinical trials. To make these consensus definitions accessible to all stakeholders in TAVI clinical research through a peer reviewed publication, on behalf of the public health.

BACKGROUND

Transcatheter aortic valve implantation may provide a worthwhile less invasive treatment in many patients with severe aortic stenosis and since its introduction to the medical community in 2002, there has been an explosive growth in procedures. The integration of TAVI into daily clinical practice should be guided by academic activities, which requires a harmonized and structured process for data collection, interpretation, and reporting during well-conducted clinical trials.

METHODS AND RESULTS

The Valve Academic Research Consortium established an independent collaboration between Academic Research organizations and specialty societies (cardiology and cardiac surgery) in the USA and Europe. Two meetings, in San Francisco, California (September 2009) and in Amsterdam, the Netherlands (December 2009), including key physician experts, and representatives from the US Food and Drug Administration (FDA) and device manufacturers, were focused on creating consistent endpoint definitions and consensus recommendations for implementation in TAVI clinical research programs. Important considerations in developing endpoint definitions included (i) respect for the historical legacy of surgical valve guidelines; (ii) identification of pathophysiological mechanisms associated with clinical events; (iii) emphasis on clinical relevance. Consensus criteria were developed for the following endpoints: mortality, myocardial infarction, stroke, bleeding, acute kidney injury, vascular complications, and prosthetic valve performance. Composite endpoints for TAVI safety and effectiveness were also recommended.

CONCLUSION

Although consensus criteria will invariably include certain arbitrary features, an organized multidisciplinary process to develop specific definitions for TAVI clinical research should provide consistency across studies that can facilitate the evaluation of this new important catheter-based therapy. The broadly based consensus endpoint definitions described in this document may be useful for regulatory and clinical trial purposes.