Hemodynamic maladaptation and left ventricular dysfunction in chronic hypertensive patients at the beginning of gestation and pregnancy complications: a case control study

Abstract

Objective: The aim of this study was to evaluate early pregnancy differences in maternal hemodynamics, cardiac geometry and function, between chronic hypertensive (CH) patients with and without the development of feto-maternal complications later in pregnancy.

Methods: We performed a case-control study on nulliparous CH treated patients. From a group of CH patients referred to our outpatient clinic at 4-6 weeks for a clinical evaluation the first consecutive 30 patients with subsequent complications (superimposed PE, abruptio placentae, uncontrolled severe hypertension with delivery <34 weeks, HELLP syndrome, FGR, perinatal death) were enrolled; the first 2 CH women with uneventful pregnancy referred after the case were enrolled as controls for a total of 60 patients. All patients were shifted to alpha-methyl dopa at the beginning of pregnancy and were submitted to an echocardiographic evaluation to assess the maternal hemodynamics, cardiac geometry, diastolic and systolic function.

Results: Patients developing complications had a lower early pregnancy heart rate (73 ± 11 vs. 82 ± 11 bpm), cardiac output (5.23 ± 1.2 vs. 6.5 ± 1.3 L/min, p<.01) and cardiac index (3.0 ± 0.7 vs. 3.6 ± 0.7 L/min/m², p<.01); higher total vascular resistance (1554 ± 305 vs. 1248 ± 243 d.s.cm^-5, p<.01) and total vascular resistance index (2666 ± 519 vs. 2335 ± 431, d.s.cm^-5/m², p<.01); higher left ventricular mass index (42.1 ± 8.6 vs. 36.9 ± 8.3 g/m², p<.01) and relative wall thickness (0.40 ± 0.05 vs. 0.36 ± 0.05, p<.01) of the left ventricle, resulting in a higher prevalence of altered cardiac geometry vs. uneventful CH controls. Diastolic and systolic dysfunction were also present with a higher E/e' ratio (10.50 ± 3.56 vs. 7.22 ± 1.91, p<.01) and a lower stress corrected midwall mechanics (89 ± 21 vs. 100 ± 22, p=.02) of the left ventricle.

Conclusion: CH treated patients developing maternal and/or fetal complications show early pregnancy altered cardiac geometry, diastolic and systolic dysfunction, and impaired hemodynamics with a high resistance circulation.

Keywords: Chronic hypertension; echocardiography; hemodynamics; left ventricular function; left ventricular geometry.