Left ventricular function in preeclamptic patients: an echocardiographic study

High-Sensitivity Cardiac Troponin I Levels in Normal and Hypertensive Pregnancy

PURPOSE

The purpose of this study was to examine the association of circulating concentrations of high-sensitivity cardiac troponin I (hs-cTn) in the various trimesters of pregnancy in patients with and without hypertension.

METHODS

This was a prospective cross-sectional study of pregnant and postnatal women aged between 18-35 years with no coexisting diseases. Serum samples were analysed for hs-TnI.

RESULTS

A total of 880 women (mean age = 29.1 years [standard deviation = 5.1 years]) were recruited with 129 (14%), 207 (24%), and 416 (47%) patients in the first, second, and third trimesters, respectively. Ninety (10%) participants were recruited in the postnatal period. During pregnancy 28 (3%) patients were classified as having pregnancy-induced hypertension and 10 (1%) as preeclampsia. High-sensitivity cardiac troponin I was measurable in 546 (62%) participants with a median of 1 ng/L (range 0 to 783 ng/L). Troponin concentrations were above the 99th percentile in 19 (2%) individuals. Patients with pregnancy-induced hypertension and preeclampsia had higher concentrations of hs-TnI (median 11 ng/L [interquartile range (IQR) 6 to 22 ng/L] vs 12ng/L [IQR 3 to 98 ng/L] vs 1 ng/L [IQR 0 to 1 ng/L]). In logistic regression modeling hs-cTnI concentration remained an independent predictor of pregnancy-induced hypertension or preeclampsia in both unadjusted and adjusted models (odds ratio 9.3 [95% confidence interval 5.8 to 16.3] and 11.5 [95% confidence interval 6.3 to 24.1], respectively, per doubling of hs-TnI concentrations).

CONCLUSIONS

Cardiac troponin measured using a high-sensitivity assay is quantifiable in the majority of young pregnant women with 2% of individuals having concentration above the 99th percentile sex-specific threshold. Patients with pregnancy-induced hypertension or preeclampsia had higher cardiac troponin concentrations. Cardiac troponin was a strong independent predictor of pregnancy-induced hypertension or preeclampsia in pregnant and postnatal women.

Cardiac remodeling in normotensive pregnancy and in pregnancy complicated by hypertension: systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review and meta-analysis was to describe comprehensively the pattern of cardiac remodeling during normotensive human singleton pregnancy and to compare it with that of pregnancy complicated by hypertension.

METHODS

We performed a meta-analysis of the current literature on cardiac remodeling during normotensive and complicated pregnancies. Literature was retrieved from PubMed (NCBI) and EMBASE (Ovid) databases. Included studies needed to report a reference measurement (matched non-pregnant control group, prepregnancy or postpartum) and measurements made during predetermined gestational-age intervals. Mean differences between reference and pregnancy data were calculated using the random-effects model described by DerSimonian and Laird.

RESULTS

Forty-eight studies were included in the meta-analysis, with publication dates ranging from 1977 to 2016. During normotensive pregnancy, most geometric indices started to increase in the second trimester. Left ventricular mass (LVM) increased by 28.36 (95% CI, 19.73-37.00) g (24%), and relative wall thickness (RWT) increased by 0.03 (95% CI, 0.02-0.05) (10%) compared with those in the reference group. During hypertensive pregnancy, LVM and RWT increased more than during normotensive pregnancy (92 (95% CI, 75.46-108.54) g (95%) and 0.14 (95% CI, 0.09-0.19) (56%), respectively).

CONCLUSIONS

During normotensive pregnancy, most cardiac geometric indices change from the second trimester onwards. Both LVM and RWT increase, by 20% and 10%, respectively, consistent with concentric rather than eccentric remodeling. Cardiac adaptation in hypertensive pregnancy deviates from that in healthy pregnancy by a greater change in LVM (95% increase from reference) and RWT (56% increase from reference). Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

The comparison of amino-terminal probrain natriuretic peptide levels in preeclampsia and normotensive pregnancy

OBJECTIVE

The purpose of this study was to evaluate the levels of amino-terminal probrain natriuretic peptide (Nt pro-BNP) in preeclampsia in comparison with normotensive pregnancy.

MATERIALS AND METHODS

Women with preeclampsia (proteinuria > or = 300 mg/24 h and at least two readings of systolic blood pressure > or = 140 mm Hg and diastolic blood pressure > or = 90 mm Hg) (n = 32 mild preeclampsia and n = 8 severe preeclampsia) were compared with normotensive women (n = 40). Serum Nt pro-BNP was measured using an electrochemiluminescence immunoassay (ECLIA) method (Nt pro-BNP, Roche) with a Roche modular analytics E170 immunoassay analyzer. Statistical analysis was carried out by the Student t-test, and a P value of <0.05 was accepted as statistically significant.

RESULTS

The median serum Nt pro-BNP was 430+/-28.91 pg/mL in preeclampsia. The levels of serum Nt pro-BNP were 74+/-16.82 pg/mL in normotensive pregnant women (P < 0.001) and significantly higher in women with preeclampsia (P < 0.001).

CONCLUSION

The higher levels of serum Nt pro-BNP in preeclamptic women may be an indicator of high left-ventricular filling pressure, and indicate left-ventricular diastolic dysfunction.

The effect of magnesium sulfate treatment on serum cardiac troponin I levels in preeclamptic women

AIM

To investigate serum cardiac troponin I levels before and after magnesium sulfate treatment in preeclamptic pregnant women.

MATERIALS AND METHODS

Fifty-five pregnant women were included in the prospectively planned study. Study group patients (n = 25) were pregnant women hospitalized with a preeclampsia diagnosis while the control group (n = 30) were pregnant women with no medical or obstetric problem who had been attending the antenatal clinic. Serum cardiac troponin I levels were compared in the normal pregnant women and in preeclamptic pregnant women. These levels were also compared in the preeclamptic women before and after magnesium sulfate treatment. Mann-Whitney U-test was used for statistical analysis.

RESULTS

Groups were similar with respect to age, gravity, parity, and gestational age. The median serum cardiac troponin I levels in preeclamptic patients was 0.20 ng/ml (0.02-4.53) before treatment and 0.09 ng/ml (0.02-3.91) after treatment, while it was 0.02 ng/ml (0.0-0.05) in the control group. The serum cardiac troponin I level in the preeclamptic group was significantly high (P < 0.01), and pretreatment values in this group were significantly higher compared with post-treatment values (P < 0.01)

CONCLUSION

Cardiac troponin I is a sensitive parameter for indicating minor myocardial damage which may occur in preeclampsia and for evaluating the efficiency of magnesium sulfate treatment.

Structural and functional changes in left ventricle during normotensive and preeclamptic pregnancy

Increased cardiac output in pregnancy is associated with cardiac remodeling and possible reduction in contractility, which may worsen in preeclampsia. Left ventricular (LV) geometry and function were compared between nonpregnant controls (n = 12) and normotensive (n = 44) and preeclamptic (n = 15) pregnant women using echocardiography. Load-independent comparisons of LV systolic function compared end-systolic stress (ESS) and rate-corrected velocity of circumferential fiber shortening (V(CFC)). Mean arterial pressures were 101 +/- 14 mmHg in preeclampsia, 76 +/- 6 mmHg in normotensive pregnancy, and 78 +/- 6 mmHg in controls (P < 0.005 vs. preeclampsia). LV mass increased during normotensive pregnancy (66 +/- 13 to 76 +/- 16 g/m(2); P < 0.05; controls, 65 +/- 10 g/m(2); P < 0.05) and was greater in preeclampsia (90 +/- 18 g/m(2); P < 0.05). In normotensive pregnancy, ESS decreased (59 +/- 9 to 52 +/- 11 g/cm(2); P < 0.05; controls, 66 +/- 14 g/cm(2); P < 0.005). ESS was greater in preeclampsia (60 +/- 14 g/cm(2); P < 0.05). In controls, there was an inverse relationship between ESS and V(CFC) (r = -0.78). The ESS-V(CFC) relationships in normotensive and preeclamptic pregnancy were unchanged from controls. We conclude that LV hypertrophy in normotensive and preeclamptic pregnancy matches changes in cardiac work, and LV contractility is preserved.

Amino-terminal pro-brain natriuretic peptide in normal and hypertensive pregnancy

OBJECTIVES

To investigate serum levels of amino-terminal pro-brain natriuretic peptide (Nt pro-BNP) as an index of left-ventricular function in normal pregnancy and pregnancies complicated by hypertension and also to investigate levels in both primigravid and multigravid women.

METHODS

Women with hypertension in pregnancy (at least two readings of systolic blood pressure > 140 mm Hg and diastolic blood pressure > 90 mm Hg) (n = 24) and normotensive women (n = 42) were included in the study. Serum Nt pro-BNP was measured using an enzyme-linked immunosorbent assay technique.

RESULTS

The median serum Nt pro-BNP level in pregnancies complicated by hypertension was 420 fmol/L, which was significantly greater than that measured in samples obtained from normotensive women in pregnancy (340 fmol/L) (p = 0.03). There was a nonsignificant trend toward increased levels in proteinuric as compared to nonproteinuric hypertension in pregnancy. Multigravida had higher Nt pro-BNP levels (n = 26; median Nt pro-BNP = 358 fmol/L) than primigravida (n = 16; median Nt pro-BNP = 278 fmol/L) (p = 0.01) in association with normal pregnancy. Multigravida also demonstrated a dramatic rise in serum Nt pro-BNP levels in association with hypertension in pregnancy (n = 13; median Nt pro-BNP = 572 fmol/L) as compared to normal pregnancy (n = 26; median Nt pro-BNP = 358 fmol/L) (p = 0.009).

CONCLUSION

Serum Nt pro-BNP is elevated in women with hypertensive disorders of pregnancy, indicating elevated left-ventricular filling pressures. Measured serum levels in both normal and hypertensive pregnancy are higher in multigravida than in primigravida.

Cardiac troponin I in pre-eclampsia and gestational hypertension

OBJECTIVE

To investigate serum cardiac troponin I, a sensitive marker of cardiac myocyte damage, in normal pregnancy and pregnancies complicated by hypertension with and without significant proteinuria.

DESIGN

Prospective cross sectional study.

SETTING

University hospital delivery suite.

SAMPLE

Serum samples obtained from women in normal pregnancy and in pregnancies complicated by hypertension with and without significant proteinuria.

METHOD

Women with hypertension in pregnancy (at least two readings of systolic blood pressure > 140 mmHg and diastolic blood pressure > 90 mmHg) (n = 26) and normotensive women (n = 43) were included in the study. Serum cardiac troponin I was measured using Beckman Access immunoassay.

MAIN OUTCOME MEASURE

Serum cardiac troponin I level in the pregnancies complicated by hypertension (with and without significant proteinuria) compared with the levels measured in normotensive women.

RESULTS

The median serum cardiac troponin I level in pregnancies complicated by hypertension was 0.118 ng/mL (n = 26) which was significantly greater than that measured in samples obtained from normotensive women in pregnancy (0.03 ng/mL; n = 43) (P < 0.0001). There were higher median serum cardiac troponin I levels in hypertensive women with significant proteinuria (0.155 ng/mL; n = 6), compared with those without proteinuria (0.089 ng/mL; n = 20; P = 0.03).

CONCLUSION

Serum cardiac troponin I is elevated in women with hypertensive disorders of pregnancy indicating some degree of cardiac myofibrillary damage in these disorders.

Relationship of systemic hemodynamics, left ventricular structure and function, and plasma natriuretic peptide concentrations during pregnancy complicated by preeclampsia

OBJECTIVE

This study was done to evaluate left ventricular structure and function among pregnant patients with preeclampsia and compare them with those of normotensive pregnant and nonpregnant subjects. It also tested the hypothesis that abnormalities in left ventricular structure and function are associated with elevated plasma levels of natriuretic peptides.

STUDY DESIGN

The study compared 75 pregnant women (n = 40 with preeclampsia; n = 35 normotensive pregnant women) and 10 nonpregnant normotensive control subjects undergoing an echocardiographic and biohumoral (renin activity and aldosterone, atrial natriuretic peptide, and brain natriuretic peptide concentrations) evaluation. The statistical analysis was carried out by analysis of variance, and significance was set at P <.05.

RESULTS

Comparison of pregnant patients with preeclampsia versus both normotensive pregnant women and nonpregnant women showed significant increases in left ventricular mass and left ventricular endsystolic and end-diastolic volumes and significant reductions in left ventricular ejection fraction and percentage of fractional shortening. These changes coincided with increases in plasma levels of atrial natriuretic peptide and brain natriuretic peptide that were linearly related to the left ventricular structural and functional changes observed in patients with preeclampsia.

CONCLUSION

Pregnant patients with preeclampsia showed adaptation to the increase in systemic blood pressure, with significant modification of left ventricular structure and function related to the plasma levels of both atrial natriuretic peptide and brain natriuretic peptide. A simple evaluation of plasma natriuretic peptide concentrations could help to discriminate patients with preeclampsia who have a condition of mild left ventricular overload.

Left ventricular mechanics in preeclampsia

Increased systemic vascular resistance and contracted blood volume are characteristic findings in preeclampsia. These alterations in cardiovascular hemodynamics can adversely affect ejection phase indices of left ventricular performance making it difficult to separate abnormalities resulting from changes in load from those caused by depressed myocardial contractility. To address this issue the contractility-sensitive, load-independent relationship between left ventricular end-systolic wall stress and rate-corrected velocity of fiber shortening was assessed in 10 nulliparous patients with preeclampsia. Comparisons were made with data obtained from 10 age-matched normotensive women with uncomplicated pregnancies (control subjects). Studies were performed by means of two-dimensionally targeted M-mode echocardiography and calibrated carotid pulse tracings during early labor, 1 day after delivery, and 4 weeks after delivery. During early labor and 1 day after delivery, patients with preeclampsia had elevated blood pressure and increased total systemic resistance. These parameters returned to normal by 4 weeks after delivery. Before delivery and 24 hours after delivery, the patients with preeclampsia had lower overall left ventricular performance (as measured by cardiac output and rate-corrected velocity of fiber shortening) and higher left ventricular afterload (as measured by left ventricular end-systolic wall stress) when compared with control subjects. These differences were no longer present 4 weeks after delivery. Despite the time-related intergroup differences in hemodynamics, left ventricular contractility was similar between normotensive and preeclamptic subjects at all stages of the study. Thus when load is eliminated as a confounding variable, the decrements in overall left ventricular performance measured in patients with preeclampsia reflect a mechanically appropriate response to increased afterload rather than an abnormality in the ventricular contractile state.

Acute hypertensive crisis in pregnancy

Severe pre-eclampsia is a state of acute afterload increase where compensation may be total by use of the Frank-Starling mechanism and/or increased adrenergic drive, or may be uncompensated in a patient with limited or exhausted preload reserve. As such, we are presented with a diverse group of patients and antihypertensive therapy ideally should be individualized. In reality we are dealing with a complex situation because of the presence of the fetus raising concerns about direct effects on the fetus as well as on uteroplacental blood flow. This limits our choice of agents to those with extensive use in pregnancy except in complicated or resistant cases. For these reasons, hydralazine is the antihypertensive agent of choice for treatment of acute hypertensive emergencies in pregnancy. In the complicated case other agents such as sodium nitroprusside or nitroglycerin may be more appropriate and, in these cases, hemodynamic monitoring should be performed to allow not only greater safety, but also to tailor therapy to the individual hemodynamic profile.

Study of the left ventricular function in pregnancy-induced hypertension

Left ventricular (LV) morphological and functional characteristics in 9 women suffering from pregnancy-induced hypertension (PIH) were studied by means of echocardiograms. In order to distinguish which changes depended on the pressure values and which were the result of pregnancy, 10 nonpregnant control women with no heart disease and 10 normal pregnant women (NP) were studied and the results of each of the groups compared. To evaluate the structure, left ventricular systodiastolic diameters and wall thickness were measured. The only statistically significant difference was in the diastolic diameters between the PIH (4.7 +/- 0.3 cm) and the control group (4.4 +/- 0.2 cm) p less than 0.01. Left ventricular mass was significantly increased (p less than 0.01) in the PIH patients (185 +/- 53.1 g) compared to the NP patients (161 +/- 29.6 g) and the control group (125 +/- 17.4 g). No statistically significant differences were found in the radius thickness ratio in the three groups. The systolic function assessed by the shortening percentage was significantly lower (p less than 0.05) in the control group (32.8 +/- 4.4%) and in the NP patients (37.8 +/- 5.2%) than in the PIH group (39 +/- 6.5%). Afterload assessed by isovolumic period stress was significantly greater (p less than 0.01) in the PIH patients (157 +/- 10.6 dyne/cm2) compared with the NP group (118.9 +/- 7.01 dyne/cm2). There were no significant differences between the first group and the control group (134.09 +/- 8.7 dyne/cm2). As evidence of the diastolic function, analysis was made, on the one hand, of diastolic isovolumic period length (DIP).(ABSTRACT TRUNCATED AT 250 WORDS)

Haemodynamic changes during the puerperium: a Doppler and M-mode echocardiographic study

Serial haemodynamic investigations were performed in 15 women at 38 weeks gestation and then 2, 6, 12 and 24 weeks after delivery. Cardiac output was measured by Doppler and cross-sectional echocardiography at the aortic, pulmonary and mitral valves. Cardiac chamber size and ventricular function were investigated by M-mode echocardiography. Flow measurements at the three intracardiac sites correlated closely. Cardiac output fell from a mean of 7.42 l/min at 38 weeks to 4.96 l/min at 24 weeks after delivery, a fall of 33%. Most of this decrease (28%) had occurred by 2 weeks. This was associated with a 20% reduction in heart rate and an 18% reduction in stroke volume. By 2 weeks after delivery there was a significant decrease in left atrial dimension and left ventricular end-diastolic dimension. Left ventricular wall thickness and mass declined throughout the period of study as did aortic, pulmonary and mitral valve areas. M-mode derived indices of myocardial contractility were all significantly reduced by 2 weeks and thereafter showed no further change. No haemodynamic differences were found between lactating and non-lactating mothers.

Early diastolic time intervals during hypertensive pregnancy

Early diastolic time intervals have been assessed by means of the echopolycardiographic method in 17 pregnant women who developed hypertension during pregnancy (HP) and in 14 normal pregnant women (N). Systolic time intervals (STI), stroke volume (SV), ejection fraction (EF), and mean velocity of myocardial fiber shortening (VCF) were also evaluated. Recordings were performed in the left lateral decubitus (LLD) and then in the supine decubitus (SD). In LLD, isovolumic relaxation period (IRP) was prolonged in the hypertensive pregnant women compared with normal pregnant women (HP 51 +/- 12.5 ms, N 32.4 +/- 15 ms p less than 0.05), whereas time of the mitral valve maximum opening (DE) was not different in the groups. There was no difference in SV, EF, and mean VCF, whereas STI showed only a significant (p less than 0.05) lengthening of pre-ejection period (PEP) in HP. When the subjects shifted from the left lateral to the supine decubitus position, left ventricular ejection time index (LVETi) and SV decreased significantly (p less than 0.05) in both normotensive hypertensive pregnant women. IRP and PEP lengthened significantly (p less than 0.05) only in normals, whereas they were unchanged in HP. DE time did not vary in either group. In conclusion, hypertension superimposed on pregnancy induces lengthening of IRP, as well as of PEP, and minimizes the effects of the postural changes in preload on the above-mentioned time intervals.

Two-dimensional and M-mode echocardiographic findings in hypertensive pregnant women

Two-dimensional and M-mode echocardiograms were obtained during the thirty-second week of gestation from 69 women classified as follows: group I, 22 normotensive primigravid women; group II, 16 primigravid women with pregnancy-induced hypertension; group III, 21 percent women with essential hypertension; and group IV, 10 normotensive nonpregnant control subjects. Systolic, diastolic, and mean arterial pressures were higher in groups II and III than in groups I and IV (p less than 0.001). Echocardiographic dimensions were significantly increased in group III compared with the other groups (p less than 0.01). No significant differences were observed among the other groups in the echocardiographic parameters or in the indices of ventricular performance studied. In echocardiographic studies, chronic hypertensive pregnant women are distinguished from patients with pregnancy-induced hypertension because the former have ventricular hypertrophy resulting from the pressure overload exerted for a long period of time. Our patients with essential hypertension experienced no changes in left ventricular performance because of the early stage of their hypertensive disease.

Cardiac size and function in pregnancy-induced hypertension

The physiologic cardiac enlargement characteristic of normal pregnancy could result in important left ventricular dysfunction in the presence of elevated blood pressure. Using M-mode echocardiography, we measured left ventricular dimensions, fractional shortening, and radius-to-wall thickness ratio in 23 patients who had a diagnosis of pregnancy-induced hypertension at rest and during isometric exercise. Seventeen subjects with normal pregnancies were similarly studied and served as controls. The average gestation of patients with pregnancy-induced hypertension was 38 +/- 2 weeks, and that of control subjects was 37 +/- 1 weeks. The average age was 25 +/- 5 years for patients with pregnancy-induced hypertension, and that for control subjects was 29 +/- 4 years. The patients with pregnancy-induced hypertension did not show the normal eccentric cardiac enlargement observed during pregnancy; the average radius-to-wall thickness ratio was reduced in patients with pregnancy-induced hypertension. Fractional shortening, a reflection of ventricular performance, was maintained both at rest and during exercise in the hypertensive group. One patient, who did not show a reduced radius-to-wall thickness ratio, had marked reduction of left ventricular performance in the presence of severe pregnancy-induced hypertension. Left ventricular performance in most subjects with pregnancy-induced hypertension is normal. Preservation of left ventricular performance despite increased arterial pressure may be related to the absence of eccentric gestational cardiac enlargement.