Author + information
- Masieh Abawi, BSc,
- Freek Nijhoff, MD, PhD,
- Pierfrancesco Agostoni, MD, PhD,
- Rehana de Vries, MSc,
- Arjen J.C. Slooter, MD, PhD,
- Marielle H. Emmelot-Vonk, MD, PhD,
- Michiel Voskuil, MD, PhD,
- Tim Leiner, MD, PhD,
- Pieter A. Doevendans, MD, PhD and
- Pieter R. Stella, MD, PhD∗ ()
- ↵∗Department of Cardiology, University Medical Center Utrecht, Heidelberglaan 100, Room E.04.210, 3584 CX Utrecht, the Netherlands
Although only 2% to 5% of patients develop symptomatic stroke following transcatheter aortic valve replacement (TAVR), new cerebral lesions have been detected among the majority of these patients using diffusion weighted magnetic resonance imaging (DWI-MRI), irrespective of access site strategy (1). According to the published reports, new cerebral DWI lesions have been associated with future neurological and cognitive decline; however, the relationship between these lesions and post-operative delirium (POD) following TAVR remains unknown. By means of this study, we aimed to assess the impact of new cerebral DWI lesions on the occurrence of POD following TAVR.
A total of 377 consecutive patients underwent TAVR in our institute between 2010 and 2015. Of these, we identified 103 patients (80 ± 8 years, logistic EuroSCORE-II 17 ± 9%) who underwent TAVR with post-procedural MRI at our center. These patients were imaged between 5 days following TAVR, and were assessed by 2 trained observers blinded to neurological outcomes (stroke/transient ischemic attack or POD). POD was rated according to the local protocol at the end of every shift by the nurse or attending physician, using the Delirium Observational Scale based on the Diagnostic and Statistical Manual Disorder–IV (DSM-IV) criteria, fourth edition. The primary outcome of the present study was the presence of POD on any day during the hospital stay after TAVR. The secondary endpoint included number, volume, and distribution of new cerebral DWI lesions. All data were prospectively collected according to the Valve Academic Research Consortium-2 criteria, and were retrospectively analyzed. All patients gave informed consent for the procedure, and because of the retrospective nature of this study, collecting known data, the requirement of a new ethical committee approval was waived.
Baseline and imaging findings are presented in Table 1. After the procedure, new cerebral DWI lesions were observed among 90% (n = 93) of patients; and 14.5% (n = 15) developed POD. Interestingly, analogous to findings after cardiac surgery (2), we observed a higher number of new DWI lesions in patients who developed POD following TAVR. These lesions were typically dispersed on both side of the brain, with significantly more on the left side. Moreover, there were no significant between-group differences (POD vs. non-POD) in DWI lesion size. Furthermore, anterior cerebral artery territories that supply brain areas important for social judgment and executive control (3) were more affected in patients with POD compared with non-POD.
Although POD is frequently detected following TAVR, its etiological mechanism remains unknown. Several mechanisms have been hypothesized by which new cerebral ischemic lesions could lead to delirium. For instance, cerebral lesions could lead to POD through alteration of cerebral acetylcholine levels, and in response to this, neuro-inflammation has been recognized as a trigger for episodes of delirium (4). Strategies to minimize cerebral lesions following TAVR, therefore, not only hold the promise of protecting patients’ physical and cognitive functions, but also theoretically may reduce the incidence of POD following TAVR. Recently, data from randomized DEFLECT III (A Prospective, Randomized Evaluation of the TriGuard™ HDH Embolic Deflection Device During TAVI) trial (5) investigating the use of a cerebral protection device showed promising results with 40% to 50% reduction of cerebral lesions and improved neurological and cognitive performance at discharge and 30 days. The current study was limited by its single-center design. Its retrospective characteristics may have led to underestimation of the incidence of delirium and inaccurate measurement of potential confounders. Although unlikely, the single MRI study performed leaves uncertainty regarding the sequence of events, because new cerebral lesions theoretically may have been inflicted after the occurrence of POD.
In conclusion, the incidence of new cerebral DWI lesions after TAVR is high. Moreover, a higher number of these lesions is associated with the occurrence of POD following TAVR. Future studies are needed to confirm our findings.
Please note: Dr. Stella is on the scientific advisory board of Keystone Heart; and is a proctor for Edwards Lifesciences. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2016 American College of Cardiology Foundation
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