In the midst of a dangerous intersection with unclear therapeutic strategies: A challenging case of severe aortic stenosis

Background: One out of seven patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) may be affected by transthyretin cardiac amyloidosis (ATTR-CA), mostly presenting with low-flow low-gradient AS with mildly reduced ejection fraction. The complex interaction of these two pathologies poses specific diagnostic and management challenges. The prognostic implications of this clinical intersection are not defined yet. Moreover, whether TAVR may have a prognostic benefit in ATTR-CA patients with symptomatic severe AS remains unclear, posing doubts on the best management strategy in this increasingly recognized subset of patients. Clinical case: We present a case of an 87-year old man with low-flow low-gradient severe AS, for whom a diagnosis of ATTR-CA was suspected based on clinical and echocardiographic criteria specific to coexisting AS and ATTR-CA. The diagnosis was eventually confirmed by positive bone tracer scintigraphy imaging. Following in-depth Heart team discussion, integrating frailty and prognostic information from combined cardiomyopathy states, a decision was made to manage the patient's severe AS conservatively. Conclusion: In the presented case, we deemed the natural history of ATTR-CA amyloidosis to negatively affect both the patient' prognosis and procedural risk, adversing TAVR indication despite symptomatic severe AS. No clear evidence is currently available to guide decision making in this setting, advocating for prospective studies to clarify if TAVR may have a prognostic benefit in ATTR-CA - and which ATTR-CA - patients.