a case report of complete heart block in a 58-year-old woman with multiple myeloma treated with carfilzomib: implications for risk stratification in high-risk populations

Carfilzomib, a proteasome inhibitor used to treat relapsed multiple myeloma, is linked to rare cardiaccomplications. complete heart block (chb), though seldom reported, poses critical risks in patients withmultiple comorbidities. this case report illustrates the development of chb in a patient with multiple myelomaand high cardiovascular risk, underscoring the importance of risk-based monitoring rather than proposing anew mechanism. a 58-year-old iranian woman with relapsed multiple myeloma, acute coronary syndrome,hypertension, dyslipidemia, type 2 diabetes, and hemodialysis-dependent chronic kidney disease (ckd)developed chb 48 hours after carfilzomib initiation. the naranjo adverse drug reaction probability scaleyielded a score of 3 (indicating a possible adverse drug reaction). discontinuation of carfilzomib andtemporary pacemaker implantation restored hemodynamic stability. although the patient's hemodynamicsimproved following pacing, she ultimately died due to septic complications unrelated to the arrhythmia. thiscase demonstrates the complexity of attributing chb to carfilzomib in a multimorbid patient. it highlights thenecessity of comprehensive cardiac evaluation and risk stratification in patients receiving proteasome inhibitors,especially those with concurrent ckd, coronary artery disease (cad), and polypharmacy.