Concomitant Transthyretin Amyloidosis and Severe Aortic Stenosis in Elderly Indian Population A Pilot Study

BACKGROUND Prevalence of both degenerative severe aortic stenosis (AS) and transthyretin cardiac amyloidosis (ATTR-CA) increases with age. Dual disease (AS+myocardial ATTR-CA) occurs in significant proportion of patients undergoing surgical aortic valve replacement (SAVR). OBJECTIVES This study aimed to determine the prevalence of ATTR-CA in severe AS in the Indian population, identify noninvasive predictors of its diagnosis, and understand its impact on prognosis. METHODS Symptomatic severe AS patients aged $65 years undergoing SAVR were enrolled. ATTR-CA diagnosis was based on preoperative 99m-technetium pyrophosphate (PYP) scan and intraoperatively obtained basal interventricular septum biopsy for myocardial ATTR-CA, and excised native aortic valve for isolated valvular ATTR-CA. Primary amyloidosis was excluded by serum/urine protein electrophoresis with serum immunofixation. RESULTS SAVR was performed in 46 AS patients (age 70 +/- 5 years, 70% men). PYP scan was performed for 32 patients, with significant PYP uptake in 3 (n = 3 of 32, 9.4%), suggestive of myocardial ATTR-CA. On histopathological examination, none of the interventricular septum biopsy specimens had amyloid deposits, whereas 33 (71.7%) native aortic valves showed amyloid deposits, of which 19 (57.6%) had transthyretin deposition suggestive of isolated valvular amyloidosis. Noninvasive markers of dual disease included low myocardial contraction fraction (median [interquartile range], 28.8% [23.8% to 39.1%] vs 15.3% [9.3% to 16.1%]; P = 0.006), deceleration time (215 [144 to 236] ms vs 88 [60 to 106] ms; P = 0.009) and global longitudinal strain (-18.7% [-21.1% to-16.9%] vs-14.2% [-17.0% to-9.7%]; P = 0.030). At 1-year follow-up, 2 patients died (4.3%); 1 each in myocardial ATTR-CA negative and positive groups (3.4% vs 33.3%; P = 0.477). CONCLUSIONS Dual disease is not uncommon in India. Isolated valvular amyloidosis in severe AS is much more common.

Automated summary

Dual disease is not uncommon in the Indian population, with isolated valvular amyloidosis being more prevalent among severe AS patients. Noninvasive markers such as myocardial contraction fraction, deceleration time, and global longitudinal strain can be used as predictors for diagnosis.