Usefulness of novel hematologic inflammatory parameters to predict prosthetic mitral valve thrombosis

Prosthetic valve thrombosis (PVT) is a life-threatening complication. Neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) have been studied as inflammatory biomarkers in atherosclerosis, but data regarding valvular disease are lacking. The study population included patients with mitral PVT (n = 152) versus control subjects (n = 164) with functional mitral prosthesis. Transesophageal echocardiography was performed to diagnose PVT. NLR and PLR were calculated using complete blood count. C-reactive protein (CRP) levels were also analyzed. Neutrophil and platelet levels did not differ between the groups (4.9 ± 2.0 vs 4.7 ± 1.5, p = 0.84 and 254.8 ± 89.7 vs 241.5 ± 62.8 p = 0.36, respectively), but lymphocyte levels were significantly lower in patients with PVT than the controls (1.8 ± 0.7 vs 2.2 ± 0.6, p <0.001). NLR, PLR, and CRP levels were significantly higher in patients with PVT than in controls (3.2 ± 2.1 vs 2.2 ± 0.8, p <0.001; 163 ± 77.5 vs 114.9 ± 37.3, p <0.001; and 1.97 ± 3.02 vs 1.02 ± 1.22, p = 0.01, respectively). A positive correlation was observed between NLR and PLR (r = 528, p <0.001). NLR level of >2.23, measured on admission, yielded an area under the curve value of 0.659 (95% confidence interval 0.582 to 0.736, sensitivity 66%, specificity 60%, p <0.001) and PLR level of >117.78 yielded an area under the curve value of 0.707 (95% confidence interval 0.636 to 0.777, sensitivity 70%, specificity 58%, p <0.001). Multivariate analysis showed that increased PLR and inadequate anticoagulation were independent predictors of thrombosis in patients with PVT. In conclusion, patients with PVT had increased NLR, PLR, and CRP levels compared with subjects with normofunctional prosthesis, and increased PLR was an independent predictor of mitral PVT.