Correlation analysis between curvature ratio measured at cardiac MR and systolic pulmonary artery pressure

Objective: To observe the value of detection of pulmonary arterial hypertension (PAH) with curvature ratio measured at cardiac MR. Methods: We performed a retrospective study of 48 patients with cardiac MR,systemic systolic blood pressure and right heart catheterization(RHC) data. The parameter curvature ratio (R_c) was measured at cardiac MR and transseptal/transmural pressure ratio (R_P) was calculated. By using the regression analysis between R_c and R_P, the SPAP was calculated. Bland-Altman analysis was used to compare the SPAP calculated with SPAP obtained by RHC. The accuracy of the SPAP calculated in detecting PAH was analyzed by using receiver operating characteristic (ROC) curves (SPAP higher than 40 mmHg as cutoff). The normality of parameter is tested by K-S test. Bivariate correlation Pearson test was used to test the consistency of parameters obtained by different measurers. Linear regression analysis was performed to find the relationship between R_c and R_P. Results: Parameter R_P = 0.28 ± 0.37 (-0.50-0.83) and R_c = 0.31 ± 0.57 (-0.78-0.97). Linear relationship was found between R_c and R_p (r = 0.94, P < 0.01) and regression equation: R_c = 1.44 × R_p - 0.09. Bland-Altman analysis showed satisfactory limits of agreement with the SPAP calculated and obtained by RHC. ROC analysis of the diagnostic value in PAH revealed 94.4% (34/36) of sensitivity and 100.0% of specificity (12/12, area under ROC curve = 0.942, P < 0.01). Conclusions: Our study suggests that with curvature ratio measured at cardiac MR,the SPAP estimated have considerable sensitivity and specificity for detecting PAH. It may be a useful non-invasive assessment in patients that suspected of PAH. (authors)