Potential mechanism of annulus rupture during transcatheter aortic valve implantation.

Although annulus rupture is one of the most severe complications of transcatheter aortic valve implantation (TAVI), the incidence and mechanism of this complication remain unclear. Out of 387 consecutive TAVI cases in our institution, the incidence of annulus rupture was 1.0% (4/387). The first two patients died because of hemodynamic collapse due to tamponade on day 0. Both surviving patients had undergone preprocedural multidetector computed tomography which revealed large calcifications in the epicardial fat part of the aortic annulus. In both cases, annulus rupture occurred after deployment of a balloon expandable valve suggesting that mechanical compression of this "vulnerable area" by calcification may cause annulus rupture.