Retrospective Analysis of Therapeutic Modalities in Prosthetic Heart Valve Thrombosis: A 15-Year Single-Center Experience

<i>Background and Objectives</i>: Prosthetic valve thrombosis (PVT) represents a rare but critical complication after heart valve replacement surgery. This study aimed to evaluate patient characteristics, treatment modalities (medical vs. surgical), and clinical outcomes in patients with PVT over a 15-year period, with a particular focus on the impact of New York Heart Association (NYHA) functional class on mortality. <i>Materials and Methods</i>: We retrospectively analyzed 76 patients with confirmed PVT (54 mitral, 20 aortic, and 2 tricuspid; 97.4% mechanical) treated at a single tertiary center between 2005 and2020. The treatment comprised intravenous unfractionated heparin (UFH) alone (<i>n</i> = 29), low-dose tissue plasminogen activator (t-PA) (<i>n</i> = 27), or surgical re-operation (<i>n</i> = 20). Primary endpoints were treatment success, in-hospital mortality, and complications. <i>Results</i>: Overall, the treatment success was 60.5% (46/76) with a 25.0% (19/76) in-hospital mortality. UFH therapy achieved a 67.6% success with a 24.3% mortality. Low-dose t-PA demonstrated a 59.3% success with a significantly lower mortality (7.4%, <i>p</i> = 0.004). The surgery showed a 50% success with a 50% mortality. Patients in the NYHA class III-IV had markedly higher mortality (68.2% vs. 11.1%, <i>p</i> < 0.001) and lower treatment success (27.3% vs. 81.5%, <i>p</i> < 0.001) compared to the NYHA class I-II. A multivariate analysis revealed NYHA III-IV as the strongest predictor of mortality (OR 12.639, 95% CI: 1.905-83.849, <i>p</i> = 0.009). <i>Conclusions</i>: The low-dose t-PA (25 mg total dose) therapy showed the lowest mortality among treatment modalities. The NYHA functional class emerged as the most significant predictor of outcomes, with the class III-IV patients having >12-fold increased mortality risk. These findings support early intervention and suggest that t-PA is a viable first-line option in selected patients.