Impact of phosphodiesterase-5 inhibitors on right ventricular function and exercise capacity after left ventricular assist-device implantation: the PIVAD study

Abstract

Background Long-term therapy with oral phosphodiesterase-5 inhibitors (PDE5I) is frequently implemented after left ventricular assist-device (LVAD) implantation to improve hemodynamics and prevent late-onset right ventricular (RV) failure or to facilitate listing for heart transplantation in individuals with persistent pulmonary hypertension. The safety and efficacy of this appoach has not been prospectively studied. Recent analyses of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) demonstrated improved survival for patients under long-term PDE5I after 48 months but higher incidence of early postoperative RV failure as well as a higher risk for gastrointestinal bleeding. Purpose To evaluate the impact of discontinuation of PDE5I in patients on LVAD support. Methods In this prospective, single-arm, interventional study we enrolled LVAD recipients on oral PDE5I (sildenafil or tadalafil) after at least 1 month post-implant who were clinically stable on optimal medical therapy. The patients underwent physical examination, ECG, 6-minute walking test, cardiopulmonary exercise testing, transthoracic echocardiography, LVAD interrogation, questionnaire based evaluation of quality of life and testing of serum biomarkers at baseline and 4 weeks after discontinuation of oral PDE5I therapy. Results From 10/2019 to 02/2021 thirty patiens were included in the study and completed the follow-up. Mean age was 54 years, 90% were male. Destination therapy was the primary treatment goal in 13% of this cohort while 87% received LVAD as a bridge to transplant. Mean dosis of tadalafil was 24.6 mg, of sildenafil 42.5 mg. At follow-up no significant changes were elicited in echocardiographic markers of RV function, peak oxygen consumption, VE/VCO2 slope, eGFR, N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration, quality of life and average flow and power readings of the device but mild increase in walking distance (Table 1). Two patients were hospitalized for non-cardiac reasons (subtherapeutic INR, driveline infection). No patient was hospitalized for cardiac decompensation. Conclusion Discontinuation of PDE5I was not associated with deterioration of RV function, exercise capacity and quality of life after 4 weeks. The risk/benefit profile of PDE5I in LVAD patients needs to be further investigated in context of randomized controlled trials. FUNDunding Acknowledgement Type of funding sources: None. Table 1