Prevalence of Point-of-Care Ultrasound Abnormalities and Raised Serum NT-proBNP in Early-Onset Preeclampsia

Preeclampsia is a multisystem disorder associated with adverse maternal and fetal outcomes. A previous study in patients with late-onset preeclampsia (LOPE), showed an association between pulmonary interstitial syndrome (PIS), detected by lung ultrasound, and elevated left ventricular end-diastolic pressure (LVEDP), measured by transthoracic echocardiography (TTE). In early onset preeclampsia (EOPE); however, the cardiopulmonary status remains poorly characterized.

This prospective observational cohort study enrolled women with EOPE with severe features. Point of care ultrasound (POCUS) assessments included lung ultrasound, TTE, and sonographic assessment of the optic nerve sheath diameter (ONSD). PIS was defined as the presence of bilateral B-lines on lung ultrasound. An ONSD >5.8 mm was considered compatible with raised intracranial pressure. Serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) and albumin levels were measured. The primary aim was to assess the association between PIS and elevated LVEDP in EOPE. Secondary aims included assessing the prevalence of POCUS abnormalities in EOPE and their association with serum NT-proBNP and albumin levels, and comparing the results with historical data from patients with LOPE.

Sixty-4 patients completed the study. There was no association between PIS and elevated LVEDP ( P = .53). PIS, diastolic dysfunction, systolic dysfunction, and elevated LVEDP were observed in 23% (95% CI, 14.4-35.4%), 52% (95% CI, 39.3-63.8%), 30% (95% CI, 19.9-42.5%), and 35% (95% CI, 24.2-47.6%) of women, respectively. Increased ONSD was noted in 2 women (3%). Median (IQR) NT-proBNP levels were significantly elevated (278 [119-678] ng/L) and associated with PIS ( P = .015) and elevated LVEDP ( P = .003). Using a threshold for NT-proBNP of 125 ng/L, the sensitivity and specificity for predicting PIS were 93.3% and 34%, and for increased LVEDP, 90.5% and 40%, respectively. Receiver operating characteristic analysis showed limited diagnostic value of NT-proBNP for PIS (AUC = 0.78) and for elevated LVEDP (AUC = 0.68). No association was found between serum albumin and PIS, systolic dysfunction, or elevated LVEDP. The prevalence of systolic dysfunction was significantly higher ( P < .01) and raised ONSD lower ( P < .01) than in historical controls with LOPE.

Lung ultrasound and TTE showed a high prevalence of PIS, systolic dysfunction, and raised LVEDP in women diagnosed with EOPE. PIS was not associated with elevated LVEDP. NT-proBNP level was significantly associated with PIS and elevated LVEDP, however clinical predictive value was limited. Women with EOPE had a higher prevalence of systolic dysfunction than those with LOPE.