According to the American Journal of Roentgenology, 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 replacement (TAVR) workup and postprocedural surveillance.
“LAEF derived from preprocedural cardiac CTA independently predicts mortality in patients with severe aortic stenosis undergoing TAVR,” concludes corresponding author U. Joseph Schoepf, MD, FACR, FAHA, FNASCI, FSCBT-MR, FSCCT, a professor of radiology, cardiology, and pediatrics at the Medical University of South Carolina’s Heart and Vascular Center.
Schoepf and colleagues’ retrospective single-center study included 175 patients with severe aortic stenosis (92 males, 83 females, with a median age of 79) who underwent cardiac CTA for clinical pre-TAVR 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 TAVR,” the study authors add.
Featured image: LAEF was calculated as (LAVmax-LAVmin)/LAVmax x 100. Given LAVmax of 109 mL and LAVmin of 80 mL,LAEF was calculated to be 27%. (Courtesy of the American Roentgen Ray Society)