Survival With Continuous Outpatient Intravenous Inotrope Therapy in the Modern Era

BACKGROUND: To describe baseline characteristics and outcomes in the largest known registry of advanced heart failure (HF) patients receiving continuous outpatient intravenous inotrope therapy. Studies evaluating the use of outpatient inotropes for palliation or as a bridge to advanced therapies were performed before current guideline directed medical and device therapy (GDMDT). There are limited data on the modern experience using outpatient inotrope (OI) therapy. STUDY QUESTION: We aimed to study current use and outcomes of OI. STUDY DESIGN: Retrospective database analysis. MEASURES AND OUTCOMES: From 2015 to 2017, 1540 advanced HF patients in a largess nationwide registry received OI with either milrinone or dobutamine. Baseline characteristics of 1149 patients data were retrospectively reviewed. Unadjusted Kaplan-Meier survival estimates censored at the time of transplant or mechanical circulatory support were reported. RESULTS: Of 1149 patients, more patients were treated with milrinone than dobutamine (64.6% vs. 35.4%). Regardless of the indication for OI, estimated 1 and 2-years survival was 61.8% and 41.6%, respectively. Milrinone use was associated with a greater 1-year survival than dobutamine (70.7% vs. 46.2%, P < 0.0001). The superiority of milrinone over dobutamine extended to all indications for OI, including bridge to transplant (85.9% vs. 71.3%, P < 0.0001), bridge to mechanical support (91.4% vs. 71%, P = 0.001), and palliation (73.6% vs. 63.3%, P < 0.001). After adjusting for indication, age, gender and weight, milrinone was associated with lower mortality than dobutamine (HR 0.50, 95% CI 0.39-0.64, P < 0.0001). CONCLUSIONS: In the largest dataset of HF patients receiving OI, survival on OI for palliation in the current era of GDMDT is significantly higher than previously reported. Compared with dobutamine, milrinone was associated with improved survival in all cohorts.