Cardiac CT angiography (CTA) derived left atrium emptying fraction (LAEF) improves predictive performance of established clinical risk scores and may be used to assess patients’ risk during pre-transcatheter aortic valve implantation (TAV) work-up and post-procedural surveillance.
This is according to a study a published in the American Journal of Roentgenology (AJR). “LAEF derived from pre-procedural cardiac CTA independently predicts mortality in patients with severe aortic stenosis undergoing TAVI,” concluded corresponding author U Joseph Schoepf from the Medical University of South Carolina’s Heart and Vascular Center, Columbia, USA.
Schoepf and colleagues’ retrospective single-centre study included 175 patients with severe aortic stenosis (92 male, 83 female; median age, 79 years) who underwent cardiac CTA for clinical pre-TAVI assessment. Maximum and minimum left atrium volumes were calculated using biplane area-length measurements, and the values were indexed to body surface area: LAVImax and LAVImin, respectively.
In their sample, a reduced LAEF independently predicted all-cause mortality within 24 months post-procedure (hazard ratio 0.97 [0.94–0.99]; p=.02). Moreover, when incorporating LAEF, the c-index of the Society of Thoracic Surgeons Predicted Risk of Mortality significantly increased from 0.64 to 0.70.
Acknowledging that atrial parameters are more commonly assessed using transthoracic echocardiography, both atrial volume and atrial function can be reliably assessed using cardiac CTA, “which now represents the gold standard for preprocedural planning in patients undergoing TAVI,” the authors of this AJR article added.