Predictive Value of Relative Apical Sparing of Longitudinal Strain on Echocardiography for Cardiac Amyloidosis.

Relative apical longitudinal sparing (RALS) on echocardiography has become an increasingly used tool to evaluate for cardiac amyloidosis (CA), but the predictive value of this finding remains unclear. This is a retrospective analysis at a single tertiary care center across 3 years. Patients were included if they had RALS, defined by strain ratio ≥2.0 on echocardiography, and sufficient laboratory, imaging, or histopathologic workup to indicate their likelihood of CA. Patients were stratified by their likelihood of CA, and contributions of other co-morbidities previously shown to be associated with RALS. Of the 220 patients who had adequate workup to determine their likelihood of having CA, 50 (22.7%) had confirmed CA, 35 (15.9%) had suspicious CA, 83 (37.7%) had unlikely CA, and 52 (23.7%) had ruled-out CA. The positive predictive value of RALS for CA was 38.6% for confirmed or suspicious CA. The remaining 61.4% of patients who were unlikely or ruled out for CA had other co-morbidities such as hypertension, chronic kidney disease, malignancy, or aortic stenosis, 17.0% of this group had none of these co-morbidities. In our tertiary care cohort of patients with RALS pattern on echocardiography, we found that fewer than half of patients with RALS were likely to have CA. Given the increasing use of strain technology, further studies are warranted to determine the optimal strategy for assessing CA in a patient with RALS.