Increased Arterial Stiffness in Pre-eclamptic Pregnancy at Term and Early and Late Postpartum: A Combined Echocardiographic and Tonometric Study

BACKGROUND: Pre-eclampsia (PE) is characterized by hypertension and proteinuria, and complicates from 3%-10% of all pregnancies. The hemodynamic pathophysiology of the heart and systemic arteries in pre-eclamptic patients has not been well described. We therefore performed a comprehensive comparison of the systemic arterial properties at term and at 6 months postpartum in women with PE and in women with normal pregnancy (NP) and in nonpregnant women with a previous pre-eclamptic pregnancy (PPEP). METHODS: The comparison included 40 patients with PE, 40 others with a PPEP (at 3.5±1.0 years postpartum), and 65 women who had had an NP. Noninvasive estimates of blood flow and pressure in the aortic root were made with echocardiography and calibrated right subclavian artery pulse traces obtained through tonometry. Total arterial compliance (C), arterial elastance (Ea), characteristic impedance (Z0), and peripheral arterial resistance (R) were estimated both through the use of a three-element Windkessel model and Fourier analysis of pressure and flow data. RESULTS: At term, Z0, Ea, and R were higher by 37%, 25%, and 23%, respectively (all P < 0.05) in women with PE than in those with an NP, and C was lower by 12% (P < 0.05). The values of Z0, Ea, and R remained elevated at 6 months postpartum in women who had had PE, and were also elevated in those with a PPEP, as compared to their values in NP. CONCLUSIONS: Our results demonstrate that pre-eclamptic pregnancies are characterized by a higher resistance throughout the arterial system. The altered arterial properties (Ea, Z0, and R) persisted at 6 months after PE and were also elevated at 3 years postpartum in women with a PPEP, indicating that PE induces long-standing cardiovascular disturbances.