Systemic Inflammatory Indices and CRP-to-Albumin Ratio in Association with Restenosis Following Percutaneous Mitral Balloon Valvuloplasty: An Observational Cohort Study

Objective: Percutaneous mitral balloon valvuloplasty (PMBV) is the treatment of choice for suitable patients with rheumatic mitral stenosis, but restenosis remains clinically relevant. This study evaluated whether preprocedural inflammatory indices are associated with restenosis after PMBV.
Method: We retrospectively evaluated 141 consecutive patients who underwent successful PMBV. Preprocedural neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), C-reactive protein (CRP), CRP-to-albumin ratio (CAR), and serum uric acid were assessed. Restenosis was defined as a mitral valve area (MVA) <1.5 cm² during follow-up. Kaplan–Meier and Cox regression analyses were used as the primary analyses. Logistic regression with 1,000-bootstrap internal validation was performed as a secondary analysis. Multivariable models were adjusted for the Wilkins score and relevant clinical covariates.
Results: During a median follow-up of 36 months (IQR, 28–44), restenosis occurred in 33 patients (23.4%). PLR, MLR, CAR, and uric acid levels were higher in patients with restenosis after false discovery rate correction (all q<0.05). In the multivariable Cox analysis, the Wilkins score was the sole independent predictor of restenosis (HR, 2.14; 95% CI, 1.43–3.20; P < 0.001), whereas CAR (HR, 1.18; 95% CI, 0.94–1.49; P = 0.16) and uric acid (HR, 1.09; 95% CI, 0.91–1.30; P = 0.34) were not independently associated with restenosis. CAR demonstrated an AUC of 0.71 (95% CI, 0.61–0.81). Adding CAR to the Wilkins score did not improve discrimination (ΔAUC=0.02; NRI=0.11, P = 0.26; IDI=0.019, P = 0.11).
Conclusion: The Wilkins score was the sole independent predictor of restenosis after PMBV. Preprocedural CAR and uric acid were associated with restenosis in unadjusted analyses but provided no independent or incremental prognostic value beyond established clinical and echocardiographic factors.

Keywords: Cox regression, CRP-to-albumin ratio, inflammatory indices, Kaplan–Meier, mitral stenosis, percutaneous mitral balloon valvuloplasty, restenosis, Wilkins score.