Abstract 18122: Cerebral Embolization during Transcatheter Aortic Valve Implantation (TAVI): A Transcranial Doppler Study.
Background: Recent MRI studies showed that TAVI is associated with a high incidence of cerebral embolization, our group having detected 115 new embolic lesions in 27/32 patients. The origin of the emboli, however, remains unclear. Microembolic showers may arise during various procedural steps such as crossing of the calcified valve, balloon valvuloplasty, aortic arch passage, device placement and implantation. We sought to evaluate each step of the transfemoral (TF) and the transapical (TA) procedure regarding cerebral embolization using transcranial Doppler (TCD).
Methods: 46 patients with a mean age of 80.1±6.7 years and a logistic EuroSCORE of 19.1±14.8% who underwent TF (n=32) and TA (n=14) TAVI were included in the study. Intraoperative TCD of both middle cerebral arteries was used to identify high-intensity transient signals (HITS) as a measure for microembolic load during all procedural steps. Additionally, neurological assessment was performed at baseline and daily during the first postoperativ week.
Results: HITS were detected in all patients and were mostly observed during valve positioning and subsequent implantation (TF: 485±270, TA: 338±138, p=0.06) followed by aortic arch passage (in the TF group only, 63±82), balloon valvulopasty (TF: 46±46, TA: 35±14, p=0.4) and initial crossing of the valve (TF: 36±60, TA: 6±9, p=0.07). TA-TAVI was shown to be associated with significantly less HITS than TF-TAVI (TF: 658±275, TA:413±173, p=0.004), most likely since the aortic arch is obviated as a source of embolism. No stroke and no clinical signs of neurological impairment were observed in any patients by NIH stroke scale rating, Mini Mental State Examination and Montreal Cognitive Assessment test.
Conclusions: Clinically silent microemboli were detected by TCD in all patients during TF- and TA-TAVI, TA-TAVI being associated with less embolization.
- © 2010 by American Heart Association, Inc.