ObjectiveTranscatheter edge-to-edge repair (TEER) is a prominent therapeutic option for mitral regurgitation (MR) patients. However, it lacks objective parameters to assess procedural efficacy. This study aims to investigate pulmonary venous (PV) flow as a surrogate for valvular hemodynamics and its associations to clinical outcomes. MethodsConsecutive MR patients who underwent TEER in our center from January 2020 to October 2021 were retrospectively investigated. PV flow parameters were measured before and after TEER, including velocity (cm/s), velocity time integral (VTI) (cm), and systolic/diastolic ratios. Primary outcomes were 1, 6, and 12 months heart failure hospitalizations (HFH) and 1 year all-cause mortality. ResultsThe cohort consisted of 80 patients. The mean age was 74.76 ± 10.13 years, 26 with primary and 54 with secondary MR. Systolic wave parameters improved significantly after TEER: mean peak velocity increased from 9.94 ± 31.95 to 35.74 ± 15.03 cm/s, and VTI from 3.62 ± 5.99 to 8.33 ± 4.72 cm. Furthermore, systolic to diastolic VTI and peak-velocities ratios showed significant improvement of 0.39 ± 0.63 to 0.81 ± 0.47 and 0.23 ± 0.66 to 0.91 ± 0.43, respectively. Using multivariable analysis, higher post-procedural SVTI was associated with less HFH: 1-month (OR = 0.72, CI [0.52,0.98]), 6-months (OR = 0.8, CI [0.66,0.97]), 1-year (OR = 0.85, CI [0.73,0.99]), as well as reduced 1-year mortality (OR = 0.64 95% CI [0.45,0.91]). Furthermore, compared to patients with SVTI ≥ 3, patients with SVTI < 3 had a higher risk for HFH at: 1-month (OR = 16.59, CI [1.48,186.02]), 6-months (OR = 12.2, CI [1.69,88.07]), and 1-year (OR = 8.61, CI [1.27,58.27]), as well as elevated 1-year mortality (OR = 8.07, 95% CI [1.04,62.28]). ConclusionPV flow was significantly improved following TEER, and several hemodynamic parameters were associated with HFH and mortality. These results may offer a basis for establishing future procedural goals to ensure better clinical outcomes.