Twelve-Month Survival on Chronic Continuous Milrinone Infusion and Proarrhythmic Complications: A Case Report and Literature Review

Advanced heart failure with reduced ejection fraction remains a major challenge, especially in patients ineligible for transplant or mechanical support. Continuous intravenous milrinone infusion is increasingly used as palliative or bridging therapy, improving cardiac output by enhancing contractility and reducing afterload, with emerging evidence of diastolic benefits; however, it carries a significant proarrhythmic risk. We present a 68-year-old male patient with advanced heart failure due to mixed cardiomyopathy, status post automatic implantable cardioverter defibrillator (AICD), and decompensated liver cirrhosis who has been on 12 months of outpatient milrinone infusion. Initially started on milrinone as a bridge to transplant, the therapy transitioned to palliation because of ineligibility for cardiac and liver transplantation. The patient showed notable symptomatic improvement, including resolution of recurrent pleural effusions that had previously required thoracentesis every one to two months. Electrocardiogram (EKG) showed occasional premature ventricular contractions (PVCs). Echocardiogram revealed an ejection fraction of 15-20% and grade 3 diastolic dysfunction. During this hospitalization for COVID-19 pneumonia, multiple arrhythmic events were noted, including frequent nonsustained and one sustained ventricular tachycardia, as well as a 19-second ventricular fibrillation episode terminated by an AICD shock. Milrinone was suspected as a key proarrhythmic factor. Additionally, candidemia associated with the chronic peripherally inserted central catheter (PICC) line was identified. After dose titration, arrhythmic episodes decreased significantly. The patient ultimately opted for comfort care and was discharged with hospice services. This case illustrates the complex nature of milrinone therapy in end-stage heart failure, balancing symptom relief against significant arrhythmic risk. Although studies show improvement in functional class and reduced hospitalizations with continuous inotropic support, survival benefits remain unclear. Our patient's prolonged 12-month survival exceeds the average reported in the literature. Outpatient milrinone infusion offers meaningful symptomatic relief and possibly extended survival in patients with advanced heart failure. Larger prospective studies are needed to define the true benefit-risk profile and mortality outcomes of chronic inotropic therapy.