Table 2.
Published V-Clamp outcome studies in dogs with myxomatous mitral valve disease.
| Study | Center/country | Cohort size (n) | Surgery years | ACVIM stage distribution | Procedural success/30-day survival | Postoperative outcomes | Notable findings |
|---|---|---|---|---|---|---|---|
| Liu et al. (8) | Clinical Medicine Institute, Zhongshan Hospital, Shanghai, China | 8 | NR | Medication-naive (not on cardiac-specific pharmacotherapy at enrollment); ACVIM staging not explicit but consistent with Stage B1 or early B2 by inclusion criteria | Procedural success 100% (8/8); all dogs survived without complications | Median total surgical procedural time 86.5 min (IQR 76–96.2); median catheterization time 23.5 min (IQR 22–33.8); significant reduction in mitral regurgitant maximum jet area (p = 0.012) and jet-area to LA-area ratio (p = 0.018) | First reported clinical use of V-Clamp in dogs; established procedural feasibility in canine mitral valve via transapical approach with TEE/fluoroscopic guidance; cohort was medication-naive and not directly comparable to advanced-disease cohorts in subsequent studies; V-Clamp device developed by HongYu Medical Technology, Shanghai |
| Potter et al. (9) | Colorado State University, United States | 50 | January 2021–April 2023 (28 months) | Stage B2: 15 (30%); Stage C < 6 mo: 25 (50%); Stage C > 6 mo: 7 (14%); Stage D: 3 (6%); B2 cases added partway through cohort after initial procedural success in Stage C/D | Procedural feasibility 96% (48/50 successful clamp deployment); procedural safety 96% (48/50 discharged from hospital); no procedural deaths; overall procedural success (deployment + discharge) 92% | Median RVol decreased 2.3 → 1.1 mL/kg (p < 0.001); median EROA 0.60 → 0.25 cm2/m2 (p < 0.001); median RF 65% → 43% (p < 0.001); learning curve documented: mean RF reduction first-half 21.6% ± 28.7%, second-half 53.2% ± 33.4% (p = 0.001); device-related adverse event rate 6.3% (3/59 implants), all nonfatal | Pivotal V-Clamp prospective feasibility study; quantifiable learning curve attributed to operator experience AND earlier-stage intervention as cohort progressed; identified anatomic caution criteria (posterior leaflet flail, A-P diameter >20 mm, posterior leaflet length <7 mm, shallow coaptation depth, wide vena contracta); 25 of devices donated by Hongyu Medical Technology; median total procedure time 190 min, median hospitalization 2 days; cohort reflects collective experience of three operators (Orton, Potter, Scansen) rather than a single-operator trajectory |
| Potter et al. (24) | Colorado State University, United States [extended cohort from Potter et al. (9)] | 111 | January 2021–January 2025 (4 years) | ACVIM stages B2, C, and D (specific distribution not detailed in available abstract) | Technical feasibility 97.3%; in-hospital mortality 6.3%; 3-month survival 86.4% | Freedom from all-cause mortality: 75% at 1 year, 67% at 2 years. Freedom from cardiac-related mortality: 80% at 1 year, 78% at 2 years. Mean RF 60.6% pre → 35% post → 30.7% at 1 year (sustained MR reduction). Sustained reverse remodeling at 1 year: LVIDdN 2.07 → 1.84; short-axis LA:Ao 2.31 → 2.08. Single clamp 80/108 (74%); two clamps 28/108 (26%) | First peer-reviewed multi-year V-Clamp outcome data; demonstrates that hemodynamic and remodeling improvements achieved in the acute postprocedural window can be sustained at 1 year and that 2-year all-cause survival approaches 67%; substantially extends the V-Clamp evidence base; same institution as Potter 2024 (extended cohort spans 4 years versus the 28-month Potter 2024 cohort); published online ahead of print December 2025 in Journal of Veterinary Cardiology |
| Lee et al. (10) | Korea Animal Medical Center, South Korea | 20 | September 2023–September 2024 (12 months) | B2: 3 (15%); C: 11 (55%); D: 6 (30%); all dogs receiving pimobendan + furosemide preprocedure | Three-month survival: 65% (13/20) overall; stage-stratified survival B2 100% (3/3), C 63.6% (7/11), D 50% (3/6); 7 deaths within 9 days postoperatively | Mitral leaflet tear/SLDA in four of seven deaths; remaining three deaths from tracheal collapse, presumed post-procedure neurologic deficit (hydrocephalus history), and presumed cardiogenic shock; SLDA attribution: three of four events to challenging anatomy (deep leaflet clefts, thickened leaflets), 1 to operator inexperience. In survivors: VHS 11.6 → 11.0, LA/Ao 2.09 → 1.69, LVIDdN 2.1 → 1.76, RF 77.83% → 55.38%, RVol 3.96 → 1.25 mL/kg at 3 months (significant reverse remodeling) | Independent center counterpoint to Potter cohort; demonstrates V-Clamp outcomes vary by center experience and patient selection; first published V-Clamp outcomes from Korea; high comorbidity burden contributed to mortality; learning curve evident with numerically improved survival between first and second halves of cohort (not statistically significant) |
| Petchdee et al. (36) | Kasetsart University, Thailand | 4 | December 2023–March 2024 | Two dogs Stage B2; two dogs Stage C | Procedural success in all four dogs (100%); 100% survival to 5–6 months follow-up | Acute MR reduction documented; partial regression of left atrial and ventricular remodeling over months 1 to 5, attributed by authors to residual MR persisting after V-Clamp | First Asian academic-center V-Clamp prospective series; explicit documentation that V-Clamp reverse remodeling can partially regress in the presence of residual MR—strengthens the argument that V-Clamp produces meaningful but often incomplete MR reduction compared to OMVR |
ACVIM, American College of Veterinary Internal Medicine; AP, anterior–posterior; EROA, effective regurgitant orifice area; IQR, interquartile range; LA:Ao, left atrial to aortic dimension ratio; LVIDdN, left ventricular internal dimension in diastole normalized to body weight; MR, mitral regurgitation; NR, not reported; RF, regurgitant fraction; RVol, regurgitant volume; SLDA, single-leaflet device attachment; TEE, transesophageal echocardiography; V-Clamp, the canine-specific transcatheter edge-to-edge repair device; VHS, vertebral heart score. Sources: Liu et al. (8); Potter et al. (9); Potter et al. (24); Lee et al. (10); Petchdee et al. (36). The four published V-Clamp cohorts span four geographically independent centers (CSU, Kasetsart, Korea Animal Medical Center, Zhongshan), and the first peer-reviewed multi-year follow-up data have been reported from CSU. Follow-up duration in published V-Clamp series ranges from acute postprocedural assessment [Potter et al. (9)] through 3–6 months [Lee et al. (10); Petchdee et al. (36)] to 1- and 2-year survival data [Potter et al. (24)]; the OMVR evidence base still extends to longer absolute follow-up (≥1,400 days at JASMINE) but the gap between the two evidence bases is narrowing.