Abstract Aims Concomitant secondary atrioventricular regurgitation is frequent in patients with severe aortic stenosis scheduled for transcatheter aortic valve replacement (TAVR). The future implications of leaving associated valve lesions untreated after TAVR remain unknown. Aim of the present study was to characterize the evolution of concomitant secondary atrioventricular regurgitations and to evaluate their impact on long-term prognosis. Methods and results We prospectively enrolled 429 consecutive TAVR patients. All patients underwent comprehensive clinical, laboratory, and echocardiographic assessments prior to TAVR, at discharge, and yearly thereafter. All-cause mortality was chosen as primary study endpoint. At baseline, severe concomitant secondary mitral regurgitation (sMR) was present in 54 (13%) and severe concomitant secondary tricuspid regurgitation (sTR) in 75 patients (17%). After TAVR 59% of patients with severe sMR at baseline experienced sMR regression, whereas analogously sTR regressed in 43% of patients with severe sTR. Persistence of sTR and sMR were associated with excess mortality after adjustment for our bootstrap-selected confounder model with an adjusted HR of 2.44 (95% CI 1.15–5.20, P = 0.021) for sMR and of 2.09 (95% CI 1.20–3.66, P = 0.01) for sTR. Patients showing regression of atrioventricular regurgitation exhibited survival rates indistinguishable to those seen in patients without concomitant atrioventricular regurgitation (sMR: P = 0.83; sTR: P = 0.74). Conclusion Concomitant secondary atrioventricular regurgitation in patients with severe AS is a highly dynamic process with up to half of all patients showing regression of associated valvular regurgitation after TAVR and subsequent favourable post-interventional outcome. Persistent atrioventricular regurgitation is a major determinant of unfavourable outcome after TAVR and proposes a window of early sequel intervention.