Cytomegalovirus (CMV) Viremia Presenting as a Heart Failure Exacerbation.

A 68-year-old male renal transplant recipient with a past medical history including chronic kidney disease (CKD) stage 3A due to type 2 diabetes mellitus, renal cell carcinoma, atrial fibrillation, prior stroke, prostate cancer post-prostatectomy, and heart failure with preserved ejection fraction (HFpEF) presented to the emergency department with worsening shortness of breath. Vital signs showed B-type natriuretic peptide (BNP) at 1,076 pg/mL, troponin at 55 ng/L without ischemic ECG changes, creatinine at 1.2 mg/dL below his baseline of 1.6 mg/dL, and a subtherapeutic international normalized ratio (INR) of 1.54. Chest X-ray revealed mild fluid congestion, leading to a diagnosis of heart failure exacerbation. Transplant nephrology consultation prompted tacrolimus level measurement, revealing supratherapeutic levels at 15.5 ng/mL, resulting in its hold. Concern for immunosuppression due to supratherapeutic tacrolimus levels prompted cytomegalovirus (CMV) and BK virus testing; BK was negative, but CMV viral load reached 106,297 IU/mL, with a positive viral load indicating active infection. Mycophenolate was held, and the patient developed a fever to 102.6°F before starting treatment for CMV viremia that resolved spontaneously. Oral valganciclovir 450 mg every 12 hours initiated CMV treatment. Renal ultrasound showed no hydronephrosis or rejection in native or transplant kidneys. He was discharged to a skilled nursing facility, with monitoring until his viral load cleared, followed by three additional months of additional valganciclovir therapy.