A Rare Case of Bicalutamide-Induced Severe Congestive Heart Failure in a Patient With Advanced Prostate Cancer

Bicalutamide, a nonsteroidal androgen receptor inhibitor, is an established therapeutic agent for advanced prostate cancer but is associated with severe cardiovascular side effects in rare cases. This case report discusses a rare occurrence of severe systolic congestive heart failure (CHF) in a 68-year-old male undergoing treatment for advanced prostate cancer with bicalutamide, without concurrent use of gonadotropin-releasing hormone antagonists. The patient presented with non-specific abdominal and bilateral foot pain. The initial assessment indicated anemia and severe dyspnea, revealing a significant decrease in left ventricular ejection fraction (LVEF) from 55% to 15% on transthoracic echocardiography (TTE), indicative of severe CHF. Bicalutamide was identified as the likely culprit given the temporal association and lack of other identifiable causes, leading to its discontinuation and initiation of guideline-directed medical therapy (GDMT). A remarkable recovery of cardiac function was subsequently observed, with LVEF improving to 60%. The patient was managed with GDMT, and a gonadotropin-releasing hormone antagonist, degarelix, was later introduced for prostate cancer treatment, along with ongoing cardiac monitoring. The recovery of LVEF and the absence of other etiologies reinforce the likelihood of bicalutamide-induced cardiotoxicity. This report underscores the importance of vigilant cardiovascular monitoring in patients receiving bicalutamide, prompt identification of cardiac dysfunction and possible mechanisms of bicalutamide cardiotoxicity, and the potential for cardiac recovery upon drug discontinuation and initiation of GDMT.