High levels of high-sensitivity C-reactive protein and uric acid can predict disease severity in patients with mitral regurgitation

Introduction Both high-sensitivity CRP (hs-CRP) and uric acid (UA) levels are known to be increased in heart failure patients and are associated with poorer functional capacity and adverse outcome. The role of these markers in patients with mitral regurgitation (MR) is less clear. The aim of this study was to assess the relationship between hs-CRP, UA and organic MR. We also assessed whether hs-CRP and UA levels are correlated with symptoms of MR, severity of MR, LV remodeling and outcome during follow-up.

Methods A total of 200 consecutive patients (87 men [43.5%]; mean age 61.6±12.5 years) with moderate or severe isolated and organic MR were included in the study. All the patients were assessed clinically and were managed and treated with standard medical therapy according to evidence-based practice guidelines. Patients were categorized according to New York Heart Association (NYHA) functional class. We assessed and graded the severity of MR using a multiparametric approach. hs-CRP was measured with chemiluminescent immunometric assay using an IMMULITE^® 1000 autoanalyzer (Siemens, Germany). Serum UA levels were analyzed using a Cobas^® 6000 autoanalyzer (Roche Diagnostics, Mannheim, Germany).

Results Mean UA levels increased significantly with NYHA class: 4.46±1.58 mg/dl for patients in NYHA class I, 5.91±1.69 mg/dl for class II, 6.31±2.16 mg/dl for class III and 8.86±3.17 mg/dl for class IV (p<0.001). Mean UA levels also increased significantly with increased severity of MR (moderate 5.62±1.9 mg/dl, moderate to severe 5.56±1.2 mg/dl, severe 7.38±3.4 mg/dl, p<0.001). There was a significant correlation between UA level and left ventricular end-diastolic diameter (r=0.40; p<0.001), left ventricular end-systolic diameter (r=0.297; p=0.001) and left ventricular ejection fraction (LVEF) (r=0.195, p=0.036), whereas hs-CRP was not correlated with these parameters. In multivariate Cox proportional hazards analysis LVEF, NYHA class and UA levels were the only independent predictors of death.

Conclusion UA and hs-CRP levels can help identify patients with asymptomatic moderate or severe mitral regurgitation. UA levels may be useful to assess the extent of left ventricular remodeling and in the optimal timing of mitral valve surgery in certain subsets of patients.