Keystone Heart is focused on protecting the brain from emboli to reduce the risk of brain infarcts during TAVR, atrial fibrillation ablation and other structural heart procedures.

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Clinical Studies


Study in Progress

REFLECT, a multi-center, randomized clinical trial of the TriGUARD™3  Embolic Deflection Device to reduce the impact of cerebral embolic lesions after TAVR. To learn more, visit the study information page at


Study Overview

ACC and EuroPCR Benefits of TriGuard™ Cerebral Protection Device During TAVR

Data presented at ACC (March 2015) and EuroPCR (May 2015) demonstrate benefits of Keystone Heart’s TriGuard™ Cerebral Protection Device during TAVR. Based upon results from the DEFLECTIII trial, the CE marked TriGuard™ Cerebral Protection Device has improved in-hospital safety outcomes and cognitive scores at discharge during Transcatheter Aortic Valve Replacement (TAVR). Based on changes in NIH Stroke Scale, patients protected with TriGuard™ had 10% absolute reduction in stroke (4.9% vs. 14.3%). Minor strokes were under detected without detailed NIHSS assessment.



Deflect III

Study Overview


  • Multicenter, prospective, single-blind, randomized controlled trial at 13 sites (EU/IL)


  • To evaluate the safety, efficacy and performance of TriGuard™ protection compared with unprotected TAVR
  • Exploratory study with no formal hypothesis testing

Sample Size:

  • 86 patients selected to benchmark events for the design of a pivotal RCT


  • Use of the TriGuard™ Cerebral Protection Device was safe and provided complete cerebral coverage in 87% of cases
  • TriGuard™ protection increased the proportion of patients completely free of ischemic brain lesions by more than 50% and reduced single and maximum lesion volume by about 40%
  • TriGuard™ appears to prevent cognitive decline and was associated with improved short-term and delayed memory at discharge compared to controls
  • Stroke was under-reported based on systematic NIHSS
  • Protected patients had a 10% absolute lower stroke rate
  • DEFLECT III provides proof of concept of the benefits of neuroprotection with the TriGuard™ device during TAVR and will benchmark event rates for a planned definitive randomized US-FDA approval trial

Deflect II

Study Overview


This study aims to evaluate the safety and performance of the new embolic deflection device TriGuard™HDH in patients undergoing TAVR.


Transcatheter aortic valve replacement (TAVR) is associated with a high incidence of new cerebral ischemic lesions. The use of an embolic protection device may reduce the frequency of TAVR-related embolic events.


This prospective, single arm feasibility pilot study included 14 patients with severe symptomatic aortic stenosis scheduled for TAVR. Cerebral diffusion weighted magnetic resonance imaging (DWI) was planned in all patients one day before and at day 4 (±2) after the procedure. Major adverse cerebral and cardiac events (MACCEs) were recorded for all patients. Primary endpoints of this study were I) device performance success defined as coverage of the aortic arch takeoffs throughout the entire TAVR procedure and II) MACCE occurrence. Secondary endpoints included the number and the volume of new cerebral ischemic lesions on DWI.


Thirteen patients underwent transfemoral TAVR and one patient a transapical procedure. Edwards SAPIEN valve prosthesis was implanted in 8 (57%) patients and Medtronic CoreValve prosthesis in the remaining 6 (43%). Predefined performance success of the TriGuard™HDH device was achieved in 9 (64%) patients. The composite endpoint MACCE occurred in none of the patients. Post-procedural DWI was performed in 11 patients. Comparing the DWI of these patients to a historical control group showed no reduction in number [median 5.5 vs. 5.0, P = 0.857], however there was a significant reduction in mean lesion volume per patient [median 13.8 vs. 25.1, P = 0.049].


This study showed the feasibility and safety of using the TriGuard™HDH for cerebral protection during TAVR. This device did not decrease the number of post-procedural new cerebral DWI lesions, however its use showed decreased lesion volume as compared to unprotected TAVR. © 2016 Wiley Periodicals, Inc.

Deflect I

Study Overview

Trial Design

DEFLECT I clinical data presented at PCR 2013 demonstrated a significant reduction of over 60% of new brain lesion volume during protected TAVR procedures using TriGuard™, compared with historical data on unprotected TAVR procedures.


  • To evaluate the safety and performance of the TriGuard™ Embolic Detection Device in patients undergoing TAVR procedures
  • CE Marked submission on first 20 consecutive patients

Study Design

  • Prospective, multi-center, single arm registry design
  • A minimum of 36 subjects up to a maximum of 60 to be enrolled at up to 10 centers in the European Union and Canada

Significant Lesion Volume Reduction

Conclusions for DEFLECT-I Study

  • Use of the TriGuard™ Embolic Deflection Device is feasible and safe in patients undergoing TAVR
  • The TriGuard™ performed as intended in 82% of cases with full coverage of all 3 cerebral vessels until completion of TAVR deployment
  • There were no TriGuard™ device-related adverse events
  • Use of TriGuard™ resulted in similar number of new lesions as historical controls
  • However, Average New Lesion Volume was smaller by 65% and the Total New Lesion Volume was 57% lower than historical controls
  • Further studies will further determine the role of TriGuard™ EDD in preventing ischemic brain injury during TAVR and other cardiac interventions

Keystone Heart is planning additional studies to support the TriGuard™ product pipeline for TAVR and other cardiovascular indications.
Please contact us for additional information.