BackgroundAlthough implantation of a left ventricular assist device (LVAD) generally improves tricuspid regurgitation (TR) in short‐term follow‐up, the clinical significance of residual TR in patients with mid‐ to long‐term LVAD support is unknown. This study aimed to identify the prevalence, predictors, and prognostic value of residual TR in LVAD patients in association with tricuspid valve (TV) deformation.Methods and ResultsThe study cohort consisted of 127 patients who underwent LVAD implantation without TV procedure and were supported with LVAD at least 1 year. All patients underwent echocardiographic examination preoperatively and 1 year after LVAD implantation. TR was quantitatively assessed by ratio of TR color jet area/right atrial area, and significant residual TR was defined as ≥20% of %TR at follow‐up echocardiographic examination. Detailed echocardiographic measurements were also performed, including TV annulus diameter, TV leaflet displacement, and left ventricular and right ventricular systolic function. LVAD implantation significantly improved ratio of TR color jet area/right atrial area as well as left ventricular and right ventricular systolic function and tethering distance (all P<0.05), whereas it enlarged TV annulus diameter (P=0.002). Significant residual TR was observed in 30 (23.6%) patients. Age, preoperative TV annulus diameter, and residual mitral regurgitation were significantly associated with significant residual TR (all P<0.05), whereas TV tethering was not. During a mean follow‐up of 21±17 months, patients with residual TR had significantly higher mortality than those without residual TR (log‐rank P<0.001).ConclusionsSignificant residual TR was observed in ≈25% patients supported with LVAD over 1 year and was associated with unfavorable outcome.