Abnormal von Willebrand Factor Function as a Superior Predictor of Clinical Outcomes After TAVI Compared to The Decrease in Platelet Count: A Prospective Study

Background and Objectives: Transcatheter Aortic Valve Implantation (TAVI) is associated with the potential for major vascular complications and arrhythmias. This study aims to identify primary predictors of these complications, emphasizing the roles of Decreased Platelet Count (DPC) and Acquired Von Willebrand Syndrome (AVWS).

Methods: We performed a prospective study with 80 patients planning to receive TAVI at the Heart Center, KMC, Rehovot, Israel. Pre-procedural evaluations include the measurement of baseline platelet counts and the functionality of the von Willebrand factor. AVWS was diagnosed through the assessment of von Willebrand factor activity and antigen concentrations. Statistical analyses utilized multivariable logistic regression to assess the associations between these predictors and clinical outcomes. Furthermore, variance inflation factor (VIF) analysis was conducted to evaluate multicollinearity among the predictor variables.

Results: Our results demonstrate that both DPC and AVWS are crucial predictors of major vascular complications. Specifically, patients with a DPC exceeding 20% exhibited an odds ratio of 4.816365 (95% CI: [1.0100, 22.9674], p = 0.049) for complications. While, patients with abnormal von Willebrand factor function presented an odds ratio of 9.84373 (95% CI: [1.601388-15.50941], p = 0.014) for complications compared to those without AVWS. ROC curve analysis indicated an AUC of 0.7417 for the DPC model and 0.8025 for the AVWS model in predicting major vascular complications. In the arrhythmia model, AVWS appeared as a significant predictor of arrhythmias, with an odds ratio of 4.480 (95% CI: [1.21, 16.49], p = 0.024). The DPC demonstrated a trend towards reduced odds of 0.36 arrhythmias (95% CI: [0.08, 1.52], p = 0.16). The model demonstrated good discriminative ability, with an area under the ROC curve of 0.7613.

Conclusions: Assessing both DPC and von Willebrand factor function is crucial for predicting post-TAVI complications, potentially enhancing risk stratification and patient management.