Abstract 14709: Dual Pathology of Severe Aortic Stenosis and Cardiac Amyloidosis: Multi-center Study of Prevalence and Outcome

Background: Elderly patients with severe aortic stenosis (AS) are increasingly diagnosed with cardiac amyloidosis (CA). It is unclear whether dual AS-CA has worse outcomes or may even result in futility of transcatheter aortic valve replacement (TAVR). Objective: To identify diagnostic predictors and outcomes of AS-CA compared to lone AS. Methods: Severe AS TAVR referrals at three international sites underwent clinical and laboratory assessment, six-minute walk test, ECG, transthoracic echocardiography with strain analysis, and blinded research 99mTc-DPD bone scintigraphy (Perugini Grade-0 negative, 1-3 increasingly positive) prior to intervention. Transthyretin CA (ATTR) was diagnosed by bone scintigraphy, unremarkable serum/urine free light chain assessment; light-chain CA (AL) was diagnosis by endomyocardial biopsy. All-cause mortality was captured from national registries. Results: 408 patients (age 83.4±6.5 years, 49.8% male) were recruited. DPD bone scintigraphy was positive in 11.6% (n=47, Grade-1 3.7%[15]) Grade-2/3 7.9%[32]). Positivity was associated with QRS duration (OR 2.5, 95%CI 1.1-5.5, p=0.02), voltage/mass-ratio (OR 0.4, 95%CI 0.2-0.9, p=0.02), history of carpal tunnel syndrome (OR 1.6, 95%CI 1.1-2.3, p=0.02). An additional two cases had biopsy proven AL-CA. Heart Team decision (blinded to bone scintigraphy) resulted in TAVR in 333 (81.6%), surgical aortic valve replacement in 10 (2.5%) and medical management in 65 (15.9%). After a median of 1.7 years, 22.9% of patients had died. AS-CA had a worse 1-year mortality than lone AS (24.5 vs 13.9%, p=0.045, Figure 1A), but there was no difference post valve intervention (p=0.7), which improved outcomes in both lone AS and AS-CA compared to medical management (Figure 1B+C). Discussion: Dual pathology of AS-CA is common in elderly AS patients. AS-CA is prognostically slightly worse than lone AS, but not if treated by valve intervention. Based on this data, TAVR should not be witheld in AS-CA.