Echocardiographic phenotype in severe aortic stenosis with and without transthyretin cardiac amyloidosis: the AMY-TAVI study.

Aims: The relative apical sparing pattern of left ventricular (LV) longitudinal strain (RELAPS > 1) has been described as a typical sign of cardiac amyloidosis (CA). The objective was to validate this pattern in concomitant CA and aortic stenosis (AS) and to identify new echocardiographic variables suggestive of CA in the presence of AS.

Methods and results: Three hundred and twenty-four consecutive patients (age 81.5 ± 5.8 years, 51% women) with AS who underwent transcatheter aortic valve implantation (TAVI) were prospectively included. 2D speckle tracking echocardiography was performed. Following TAVI, 99mTc-DPD scintigraphy and protein electrophoresis were performed to screen for CA. Thirty-eight patients (11.7%) showed cardiac uptake in scintigraphy: 14 patients (4.3%) with Grade 1, 13 (4%) with Grade 2, and 11 (3.4%) with Grade 3. Patients with Grades 2 and 3 (AS-CA group) had more LV hypertrophy (LV mass index: 188 vs. 172 g/m2, P = 0.032), lower transvalvular aortic pressure gradient (P < 0.003), and higher prevalence of low-gradient AS (50% vs. 19%, P = 0.001), as well as greater diastolic and systolic dysfunction. Strain analysis was limited to 243 patients due to poor acoustic window and restrictions imposed by the COVID-19 pandemic (81 lost: 79 in AS alone, 1 each in AS-DPD1 and AS-CA groups). RELAPS > 1 was more prevalent in AS-CA group (74% vs. 44%, P = 0.006). An echocardiographic prediction model (GRAM score) for CA in the presence of AS, which is more sensitive and specific than RELAPS > 1 alone, is proposed using the LV mass, maximum aortic gradient, and RELAPS > 1, in addition to age (area under the curve: 0.85, 95% confidence interval: 0.77-0.93).

Conclusion: RELAPS > 1 is more prevalent in AS-CA but can occur in almost half of AS patients without CA, which reduces its value as a screening tool. A more sensitive and specific prediction score for CA in patients with severe AS is proposed.