Pulmonary hypertension complicating pregnancy: cardiac remodeling and residual concerns

To assess pulmonary artery pressure and cardiac remodeling in pregnancy in women with pulmonary hypertension and compare these findings with studies done beyond three months postpartum.

Pregnant women with pulmonary hypertension from 2006 to 2017 were studied. Pulmonary hypertension was diagnosed when the pulmonary artery pressure exceeded 30 mmHg as estimated by right ventricular systolic pressure (RVSP) on echocardiography or 20 mmHg measured directly by mean pulmonary artery pressure (PAPm) with right-heart catheterization (RHC). Disease severity was assigned using threshold cutoffs. Indices of cardiac remodeling were compared during pregnancy after 20 weeks' gestation and again beyond three months postpartum when available. Pulmonary artery pressures obtained by echocardiography versus right-heart catheterization were also compared.

Forty-six pregnancies complicated by pulmonary hypertension in 41 women were identified. The study included 43 pregnancies that resulted in a livebirth. There were 20 women in whom studies were performed after 20 weeks' gestation and again at least 3 months postpartum or later. Pulmonary artery pressures determined during pregnancy versus beyond three months postpartum were not significantly different when measured by echocardiography (RVSP 53.5 ± 20.5 mmHg and 46.7 ± 20.4 mmHg, p = .26) in this limited cohort. In the 10 women in whom pulmonary artery pressures were measured with both echocardiography and right-heart catheterization, the former was found to significantly overestimate directly measured pulmonary artery pressure (63.3 ± 20.7 versus 37.7 ± 12.3 mmHg, p < .001).

Pulmonary artery pressures did not appreciably change during pregnancy after 20 weeks' gestation compared with pressures measured again beyond three months postpartum. Women with pulmonary hypertension did not show evidence of remodeling of left ventricular mass or relative wall thickness when measured in pregnancy after 20 weeks' gestation compared with beyond three months postpartum in this limited cohort. These findings suggest that cardiac remodeling in women with pulmonary hypertension is different from that of normally pregnant women and confirms the need for careful long-term follow-up.