Results
A total of 72 patients undergoing RHC were included in this study. Patients included 34 cases of atrium septal defect (ASD), 24 cases of ventricular septal defect (VSD) and 14 cases of patent ductus arteriosus (PDA).
Patients were divided in three groups based on mPAP and RV function as follows; group 1: patients with PHTN without significant RV dysfunction (n=25), group 2: patients with PHTN with significant RV dysfunction (n=22), group 3: patients with normal PAP (n=25). Mean age of the subjects was 40.90 ± 13.28 years old. There was no significant difference between groups in terms of age (p=0.726). Majority of subjects were female (51, 70.8%). There was no significant difference between groups in terms of gender distribution (p=0.553). Comparison of the echocardiographic findings of the study subjects are presented in Table 1. There was a significant difference in terms of A/S (p<0.001) between group 1 and 3. There was a significant difference in terms of S velocity(p=0.021), D (p=0.010), S/(S+D) (p<0.001), S/D (p<0.001) and S/D (p<0.001) between group 2 and 3. There was a significant difference in terms of S velocity (p<0.001), D velocity (p=0.010), S/(S+D) (p<0.001), and S/D between group 1 and 2.
The multinomial logistic regression was used to assess the relationship between PHTN and echocardiography parameters with control group as reference. The analysis revealed a significant relationship between A velocity and PHTN among patients with significant RV dysfunction (p=0.033) and PHTN without significant RV dysfunction (p=0.020). At cut-off value of 39.5 cm/s, A velocity could detect PHTN with significant RV dysfunction with sensitivity and specificity of 77.3% and 56.0%, respectively. At cut-off value of 38.5 cm/s, A velocity could detect PHTN without significant RV dysfunction with sensitivity and specificity of 76.0% and 51.0%, respectively.
The ROC curve analysis was performed to assess the sensitivity of systolic filling fraction (S/S+D )in detecting normal SPAP in the study population. The area under curve was 0.718. Considering the cut-off value of 0.535 for systolic filling fraction, the sensitivity and specificity of S/S+D for detecting normal SPAP were 80% and 64%, respectively (Figure 1).