Review of reported causes of device embolization following trans-catheter aortic valve implantation.

Transcatheter heart valve (THV) embolization is a rare but serious complication of transcatheter aortic valve implantation. Studies, including case reports, case series, and original reports published between 2002 and 2013, with regard to THV embolization were identified with a systemic electronic search using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. A total of 19 publications describing 71 patients were identified. Most patients (64%) were men, with a mean age of 80 ± 6 years and a mean logistic European System for Cardiac Operative Risk Evaluation score of 22.4 ± 9.3%. Balloon-expandable valves were used in 72% of the patients. The reported transcatheter aortic valve replacement access site was transfemoral in 80% of patients. Most cases (90%) occurred <1 hour after implantation, whereas 10% had late embolization (range 4 hours to 43 days). The most common site of embolization was the ascending aorta (38%), followed by the left ventricle (31%), descending aorta (23%), and aortic arch (8%). Open-heart surgery was required in 28% for valve retrieval and replacement. The 30-day stroke and mortality rates were 11% and 17%, respectively. Ventricular embolization and urgent conversion to open-heart surgery were significantly associated with death during hospitalization (p = 0.017 and p = 0.029, respectively). Likely causes of embolization were identified in 59 patients, with positioning error as the most commonly reported (47%), followed by pacing error (13%). In conclusion, THV embolization occurred early after transcatheter aortic valve implantation. The ascending aorta was the most common site of embolization. Higher 30-day stroke and mortality rates were associated with THV embolization compared with most published series of transcatheter aortic valve implantation outcomes.