Data for intervention lost in translation


In his presentation at the 2005 TransCatheter Therapeutics (TCT) meeting in Washington DC, Dr William A Gray highlighted the fact that as more evidence emerges for superfemoral artery (SFA) intervention, the data is often lost in translation.

Gray summarized the challenges in data analysis for superfemoral artery stents that require an understanding of the potentially confounding factors in restenosis outcomes assessment.

The first issue is the period of time the patient has had vascular disease. Anatomical factors which influence restenosis outcomes assessment include; occlusion vs. stenosis, inflow/run-off status, vessel diameter and atheroma volume. In addition, patient factors such as gender, diabetes and history of smoking must be understood and consequently analysed, Gray said.

There are also challenges to understand and overcome in developing an effective device platform. For example, Grey cited the nitinol stent and whether this should be a slotted tube or spiral design. In addition, he said that the rate of stent fracture in self-expanding platforms was not fully understood.

Finally, Grey said that clinicians also faced challenges in data collection such as endpoint definitions of success and the effectiveness of discrete vs diffuse vs volume definitions. There were also issue surrounding quantifying and understanding restenosis (angiographic, Duplex, intravascular ultrasound). This is compounded by the need for consistent and standardized reporting structures.

Dr Gray concluded that “analysis of SFA data is encumbered by the lack of Level 1 data, the lack of uniform reporting, including accounting for confounding differences in lesion/patient characteristics and standard time interval defining success etc, small sample sizes and possible differences in stent performance and durability. Dr Gray called for updated reporting standards and warned the “cardiologists (especially) need to be more discerning in their interpretation of the data presented to them.”