Results
A total of 159 children were included in this study, 150 of which had useable echocardiographic data. 39 children were identified as having clinically-diagnosed pulmonary hypertension while 111 children had an atrial septal defect requiring closure in the cardiac catheterization laboratory. Slightly over half (56%) of patients were less than 5 years of age, approximately 13% of patients were between the age of 5-10 years, 20% between the age of 10-15, and 11% were between 15-21 years. The mean age of the total group of patients was 7.1 years (SD=5.3), with a minimum age of 54 days and a maximum of 19.1 years. The echo was obtained at a median of 6.5 days (0-88 days) prior to the catheterization.
A table summarizing the echocardiographic and catheterization findings of the two groups (ASD and pulmonary hypertension patients) is provided below (Table 1).
An EDSPA of ≤39° predicted a mean MPA pressure >20 mmHg (as measured by cardiac catheterization) with a 76% sensitivity and 76% specificity (AUC 0.85) (Figure 3) and an EDSPA of ≤37° predicted a mean MPA pressure >40 mmHg (as measured by cardiac catheterization) with a 80% sensitivity and 81% specificity (AUC 0.85). A graphical depiction of the EDSPA values in those with MPA pressures less than and greater than 40 mmHg is seen in figure 4. In addition an EDSPA ≤40° predicted a RV/LV systolic pressure ratio >0.5 (as measured by cardiac catheterization) with a 76% sensitivity and 77% specificity (AUC 0.888) (Figure 5).
Inter-observer variability between the two readers was small with a Pearson correlation coefficient of 0.913 (p <0.001) and the Lin’s correlation coefficient of 0.907 when using a mean of the 3 measurements per observer (Figure 3). In addition, intra-observer variability was low with an intraclass correlation coefficient (ICC) for each observer of 0.95 (0.9-0.97 95% CI) for reader 1 and 0.94 (0.89-0.97) for reader 2.