New analysis of the PROTECTED TAVR trial has shown a reduction in stroke within the US portion of the trial.
Data presented during a late-breaking trial session at TCT 2024 by Samir Kapadia (Cleveland Clinic, Cleveland, USA), simultaneously published in JAMA Cardiology, outline the regional differences in stroke outcomes among patients taking part in the trial.
PROTECTED TAVR was among the headline-grabbing trials at TCT 2022, where Kapadia presented findings from the randomised, multicentre trial, conducted in 51 centres in North America, Europe and Australia.
The trial was conducted among 3,000 aortic stenosis patients undergoing transcatheter aortic valve implantation (TAVI) with or without cerebral embolic protection using the Sentinel (Boston Scientific) device. Devices like Sentinel are intended to mitigate the risk of stroke during TAVI by capturing and removing debris dislodged during the procedure before it reaches the brain, however their benefit remains unproven.
PROTECTED TAVR, however, failed to show a significant effect on the incidence of periprocedural stroke in favour of the device, even though a difference in rates of disabling stroke did favour Sentinel.
More recently, analysis of data from the TVT registry has demonstrated a “small, borderline significant” reduction in in-hospital disabling stroke when using embolic protection. Of note, the research showed a steady growth in embolic protection device usage throughout the duration of the study followed by a decline and plateau coinciding with the release of the PROTECTED TAVR trial results.
Looking in more detail at the data from PROTECTED TAVR, Kapadia and colleagues divided the trial’s population into a US and OUS cohort, comprising 1,833 and 1,167 patients respectively. Among the US cohort, 919 underwent TAVI alone, and 914 underwent TAVI with Sentinel. In the OUS cohort, this number stood at 580 for TAVI alone and 587 for TAVI with Sentinel.
Kapadia and colleagues identified some key differences and baseline and procedural characteristics between the US and OUS cohorts of the trial, highlighting in particular a difference in the rates of medically-treated diabetes (29.7% in the US population and 24.9% OUS), history of peripheral vascular disease (13.2% vs. 7.6%), coronary artery disease (60.3% vs. 54.2%) and atrial fibrillation (29.9% vs. 37.3%), whilst more patients in the US cohort (77.7%) were treated using balloon expandable valves than among OUS patients (42.4%). Additionally 27.5% of patients underwent predilatation prior to TAVI in the US cohort, compared to 60.1% in the OUS cohort.
Results showed that patients treated in the USA had a 50% relative reduction for both stroke, which stood at 2.6% for patients in the TAVI only arm and 1.3% for patients in the TAVI + Sentinel arm, as well as disabling stroke, which occurred in 1.5% of TAVI only patients and 0.4% of Sentinel patients. In the OUS patients, these figures stood at 3.3% and 3.7% for stroke in non-Sentinel and Sentinel patients, and 1% vs. 0.7% for disabling stroke in Sentinel vs. non-Sentinel patients.
Additionally, Kapadia reported that after a stroke, 36% of patients in the US cohort and 22% of patients OUS were discharged within 72 hours of the procedure, whilst US patients were more likely to be released home rather than to another hospital. In both regions, use of Sentinel was associated with a greater likelihood of being discharged home with no services. Furthermore, 58% of patients in the US and 68% of patients OUS required a hospital stay longer than 72 hours after the occurrence of a stroke.
Kapadia described the findings as hypothesis generating, given that the sub-group analyses were not powered to detect treatment differences in clinical outcomes, but concluded that regional differences in patient characteristics and procedural practices may impact the effectiveness of Sentinel in reducing TAVI-related stroke.
