Background: There has been a persistent debate in pediatricians on whether or not patients with congenital heart disease with large left-to-right shunt and pulmonary hypertension (PH). The severity of pulmonary hypertension has a strong impact on the effectiveness of operative treatment and prognosis. Invasive assessment with cardiac catheterization has been used to obtain more accurate data on pre- and post-operative hemodynamic change in order to study the relationship between the age at operation and prognosis in children with severe pulmonary hypertension.

Methods: Forty children with severe PH (increased total pulmonary circulation resistance) caused by ventricular septal defect (VSD) were divided into two groups according to their age at operation. Group I were younger than 2 years old and group II older than 2 years old. The ratios of pulmonary arterial pressure to systemic arterial pressure (Pp/Ps), pulmonary resistance to systemic resistance (Rp/Rs), and the levels of pulmonary vascular resistance (PVR) to small pulmonary arterial resistance (PAR) were measured before surgery, 1 week after surgery, and 5-7 years after surgery.

Results: No differences in Pp/Ps, Rp/Rs, PVR and PAR before surgery were observed between group I and group II (P>0.05) in contrast to significant differences in Pp/Ps, Rp/Rs, PVR and PAR 1 week and 5-7 years after surgery (P<0.01). In group I a week after surgery, Pp/Ps was 0.32±0.05, Rp/Rs 0.24±0.06, PVR 235.49±71.64 mmHg, and PAR 194.29±46.54 mmHg; 5-7 years after surgery, Pp/Ps was 0.24±0.03, Rp/Rs 0.19±0.05, PVR 158.26±36.51 mmHg, and PAR 119.70±32.48 mmHg. In group II a week after surgery, Pp/Ps was 0.50±0.15, Rp/Rs 0.42±0.14, PVR 381.23±35.96 mmHg, and PAR 347.07±87.52 mmHg; 5-7 years after surgery, Pp/Ps was 0.34±0.08, Rp/Rs 0.26±0.08, PVR 328.18±32.65 mmHg, and PAR 274.89±68.57 mmHg. During follow-up in group I, all the hemodynamic parameters were normal, whereas in group II, only Pp/Ps and Rp/Rs were close to normal and the other 6 parameters were still abnormal.

Conclusions: Early operation would be the only way to gain optimal long-term result and decrease the incidence of pulmonary vascular disease in children with PH due to VSD.