Post-milrinone Administration: Right Ventricular Strain in Right Ventricular Heart Failure-An Observational Echocardiographic Study

Background: Heart failure significantly affects patient morbidity and mortality, necessitating effective management strategies. Milrinone, a phosphodiesterase-3 inhibitor, has been used to improve cardiac function, but its impact on right ventricular (RV) function requires further investigation. Objectives: This study aimed to evaluate the effect of intravenous milrinone on RV function in patients with RV heart failure, with a specific focus on echocardiographic parameters before and after treatment. Methods: A prospective observational study was conducted at Shahid Rajaei Cardiovascular Medical and Research Center. Twenty-five patients with RV heart failure were included in this study. Each patient received a bolus dose of 50 µg/kg milrinone, followed by an infusion of 0.40 to 0.80 µg/kg/min for 20 minutes. Echocardiographic assessments, including right ventricular strain (RVS), pulmonary artery pressure (PAP), and other relevant parameters, were performed before and after milrinone administration. Results: The study comprised 25 patients (15 males and 10 females). Significant improvements in RV function were observed following milrinone administration. Pulmonary artery pressure decreased significantly from 57.16 ± 31.89 mmHg to 39.86 ± 21.75 mmHg (P < 0.001). Four-chamber RVS improved from -8.75 ± 4.01 to -10.58 ± 4.66 (P = 0.025). Additionally, there was a notable enhancement in free wall RVS. Patients with a history of beta-blocker use exhibited more pronounced improvements in right heart function post-milrinone administration compared to those without such a history. Conclusions: Intravenous milrinone significantly improves RV function in patients with RV heart failure, as evidenced by reductions in PAP and enhancements in RVS. The observed benefits were particularly marked in patients with a history of beta-blocker use, indicating a potential synergistic effect. These findings underscore the importance of tailored therapeutic strategies in managing right heart failure.