Abstract: FR-PO142
Delayed Diagnosis of Multiple Myeloma and Amyloidosis Due to Anchoring and Availability Biases Attached to Cardiorenal Syndrome
Session Information
- AKI: Diagnosis and Outcomes
October 25, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 102 AKI: Clinical, Outcomes, and Trials
Authors
- Conway, Alexandra E., Dartmouth College Geisel School of Medicine, Hanover, New Hampshire, United States
- Block, Clay A., Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, United States
- Hopley, Charles Wilfley, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, United States
Introduction
Anchoring bias (excess reliance on initial information) and availability bias (shortcuts based on prior/recent experience) are among the most common types of cognitive biases resulting in diagnostic errors. We present a case of a 75-year-old man with CKD and episodic AKI in the context of heart failure with preserved ejection fraction (HFpEF). The patient’s history and the prevalence of cardiorenal syndrome (CRS) resulted in adoption of this diagnosis without additional investigation until work up for frank hypercalcemia revealed plasma cell dyscrasia.
Case Description
A 75-year-old man with a history of afib, HFpEF, tricuspid and mitral regurgitation, pulmonary hypertension, hypertension, macrocytic anemia, monoclonal gammopathy of undetermined significance (MGUS), and two prior episodes of dyspnea and AKI attributed to CRS, presented with altered mental status, bradycardia, complete heart block, hyperkalemia (7 mmol/L), hyponatremia, AKI (creatinine 4.82 mg/dL vs 2.1 baseline), and hypercalcemia requiring renal replacement therapy and insertion of a permanent pacemaker. Echocardiography demonstrated preserved ejection fraction without specific amyloidosis features. Due to hypercalcemia, the patient’s previously known paraprotein was reevaluated and found to have increased (0.8 to 1.6 g/dL). The kappa-to-lambda free light chain ratio was increased to 10.8 (normal 0.4 to 2.6). Bone marrow biopsy demonstrated a plasma cell infiltrate diagnostic of IgG-kappa multiple myeloma as well as kappa light chain (AL) amyloidosis.
Discussion
The patient's CKD and episodic AKI were previously attributed to CRS due to the availability of and anchoring on this common diagnosis. Multiple myeloma/amyloidosis were not considered until hypercalcemia occurred despite clues such as macrocytic anemia, proteinuria, and prior MGUS diagnosis. Clinicians also relied on the absence of amyloidosis echocardiographic stigmata (e.g. relative apical sparing of longitudinal strain), although these features are insensitive and amyloidosis is underdiagnosed in patients with HFpEF. The absence of such findings should not dissuade clinicians from further investigation, and index of suspicion should remain high when signs are not explained by HFpEF. This case highlights the power of availability and anchoring biases to delay diagnosis.