Concurrent light chain and transthyretin cardiac amyloidosis: A case report and review of the literature.

RATIONALE: Cardiac amyloidosis is caused by extracellular deposition of amyloid proteins, with over 30 distinct forms identified based on protein composition. The predominant types are immunoglobulin light chain and transthyretin (ATTR) amyloidosis. This study presents an exceedingly rare case of concurrent light chain cardiac amyloidosis (AL-CA) and ATTR cardiac amyloidosis. PATIENT CONCERNS: A 69-year-old Chinese woman was admitted to the hospital due to recurrent heart failure that had been present for the past 3 months. She presented with symptoms including fatigue, reduced exercise tolerance, and difficulty breathing when reclining flat. She exhibited inadequate response to anti-heart failure therapy. DIAGNOSES: The diagnosis of coexisting AL-CA and wild-type transthyretin cardiac amyloidosis was confirmed through a combination of echocardiography, blood tests, cardiovascular magnetic resonance imaging, technetium-99m pyrophosphate scintigraphy, invasive procedures (bone marrow and endomyocardial biopsies), mass spectrometry, and genetic testing. INTERVENTIONS: Prior to diagnosis, the patient was treated for heart failure with preserved ejection fraction with diuretics, sodium-glucose cotransporter-2 inhibitors, and angiotensin receptor-neprilysin inhibitors. Following confirmation of cardiac amyloidosis, tafamidis was initiated to stabilize ATTR. Chemotherapy was subsequently attempted after hematologic referral but discontinued due to adverse effects. The patient later ceased most prescribed therapies in favor of unproven alternatives. OUTCOMES: After 3 months of comprehensive treatment, the patient discontinued tafamidis and other related therapies due to intolerance of adverse effects, opting instead for traditional Chinese medicine. Subsequent poor treatment adherence prevented regular follow-up and reassessment. Although the patient reported persistent exertional dyspnea during sporadic follow-up visits, no objective disease progression parameters (e.g., N-terminal pro-B-type natriuretic peptide levels, cardiac imaging changes) or standardized treatment response data were obtained. LESSONS: We report a confirmed case of coexistent AL-CA and wild-type transthyretin cardiac amyloidosis, validated through comprehensive diagnostic evaluation. Although dual therapy targeting both amyloid types may be needed, the lack of guidelines and follow-up data highlights the need for standardized management approaches. Future studies should prioritize long-term outcome tracking.