Can balloon aortic valvuloplasty help determine appropriate transcatheter aortic valve size?

OBJECTIVES: We sought to study the potential role of balloon aortic valvuloplasty (BAV) in sizing the aortic annulus in patients before transcatheter heart valve (THV) implantation.
BACKGROUND: Despite clinicians' growing experience with THV procedures, the best method of annulus sizing remains unclear.
METHODS: Twenty-three patients with aortic stenosis (<1.0 cm(2)) who were undergoing surgical valve replacement were enrolled. Pre-operative echocardiographic measurements of the annulus and computed tomography measurements of valve calcium were made. Intraoperatively, a valvuloplasty balloon of known size and inflatable pressure was inserted into the aortic valve and inflated. The development of intraballoon pressure in addition to the nominal inflation pressure (AIBP) reflected the apposition of balloon and valve. Surgical annulus was measured by cylindrical sizers.
RESULTS: In patients with tricuspid valves, AIBP was generated in 11 of 12 patients when the balloon diameter was greater than the surgically measured annulus, regardless of leaflet calcification (2 of 10 patients when balloon < or = surgical annulus). In bicuspid valves, high AIBP ( approximately 1 atm) was encountered with balloons that were within 1 mm of annulus size, and leaflet dehiscence occurred with larger balloons (n = 2 patients). Annulus size was underestimated by transthoracic echocardiogram and transesophageal echocardiogram compared with surgery (p < 0.001): transthoracic echocardiogram = 21.5 +/- 1.8 mm, transesophageal echocardiogram = 22.0 +/- 1.6 mm and surgical = 23.2 +/- 1.9 mm (range 20 to 27 mm, mode 22 mm).
CONCLUSIONS: These data suggest that measuring AIBP during balloon aortic valvuloplasty in tricuspid valves is an important adjunctive measurement of the aortic annulus and may help in determining the appropriate THV size.