Hemodynamic relationship between ophthalmic artery and uterine artery in pre-eclampsia: pulse wave reflection and transmission might provide the missing link

Ophthalmic artery Doppler in the complementary diagnosis of preeclampsia: a systematic review and meta-analysis

OBJECTIVE

To evaluate the accuracy of different parameters of the ophthalmic artery Doppler (OAD) in the complementary diagnosis of preeclampsia (PE).

METHODS

This meta-analysis adhered to the PRISMA guidelines. To investigate the mean difference in OAD values, peak systolic velocity (PSV), end-diastolic velocity (EDV), second systolic velocity peak (P2), resistance index (RI), pulsatility index (PI), and peak ratio (PR), between PE cases (overall and according to severity) and controls, random-effects meta-analyses were conducted for each Doppler parameter, with overall PE and mild and severe PE subgroups. Diagnostic performance and heterogeneity were evaluated with summary receiver operating characteristic (sROC) curves and 95% confidence intervals obtained with bivariate models.

RESULTS

Eight studies stratified the results into mild and severe or late and early PE, involving 1,425 pregnant women. PR and P2 had better diagnostic performance than the other indexes, with the PR of AUsROC at 0.885, the sensitivity of 84%, and specificity of 92%, with a low false-positive rate of 0.08 and the P2 with AUsROC of 0.926, the sensitivity of 85% and specificity of 88%. RI, PI, and EDV showed good performance and consistency across studies but lower AUsROC values of 0.833, 0.794, and 0.772, respectively.

CONCLUSION

Ophthalmic artery Doppler is a complementary tool with good performance for the diagnosis of overall and severe preeclampsia, with high and best sensitivity and specificity when using PR and P2 parameters.

Second systolic peak in fetal middle cerebral artery Doppler after intrauterine transfusion

OBJECTIVE

To evaluate functional relationship between fetal circulatory response to intrauterine transfusion (IUT) as a circulatory challenge and appearance of second systolic peak (P2) in middle cerebral artery (MCA) based on hemodynamic principles.

METHODS

According to the concept of pulse wave (PW) propagation and reflection in adults, PWs arrive twice at cerebral circulation, as primary wave caused by left ventricle ejection and secondary after reflection in peripheral arteries. Thus adults show a biphasic contour of systolic blood flow in cerebral arteries. Similar waveforms may appear in fetal MCA-Doppler, as a response to IUT as a circulatory challenge. This is a proof-of-principle study, applying classical hemodynamic principles to fetal circulation. Accordingly, appearance of MCA-P2 may indicate vasoconstriction with increased PW reflection and timing of P2(Δt) should agree with the additional PW travel time down to reflection and return (Tr). To test this agreement, we searched our database for IUTs performed for severe fetal anemia, and compared Δt, obtained by Doppler, with Tr, obtained by hemodynamic calculation using human fetal data. Level of agreement was assessed using Bland-Altman-Plots.

RESULTS

We identified 21 fetuses with adequate Doppler quality for Δt evaluation. In four cases (19%) MCA-P2 was observed before the intervention, and in 17 interventions (81%) thereafter; a highly significant association between IUT and P2 appearance (p < 0.001). In these 17 interventions good agreement of P2 timing was found between Doppler assessment: Δt = 80 ± 8 ms, and hemodynamic calculation: Tr = 76 ± 4 ms.

CONCLUSION

P2 appearance in fetal MCA-Doppler seems to indicate PW reflection due to increased vasoconstriction after IUT. Thus hemodynamic considerations might enable Doppler monitoring of fetal vasoconstriction.

Performance of ophthalmic artery Doppler velocimetry in the complementary diagnosis of preeclampsia

OBJECTIVES

To calculate the accuracy (A) and establish the best cutoff value for ophthalmic artery (OA) Doppler velocimetry indexes in patients diagnosed with preeclampsia (PE), compared with healthy pregnant women.

METHODS

This prospective experimental study enrolled 268 women: 133 with PE and 135 healthy pregnant women. All patients were evaluated by OA Doppler sonography, bilaterally, to assess their pulsatility index (PI), resistance index (RI), peak systolic velocity (PVS), second peak systolic velocity (P2), end-diastolic velocity (EDV), and peak ratio (PR). Means were compared using Student's T-test. Receiver Operating Characteristics (ROC) curve was used to establish the cutoff value and estimate the sensitivity (S), specificity (Sp), accuracy (A) of all variables, and a significance of 95% was adopted.

RESULTS

ROC curve analysis showed that P2 and PR were superior to the other parameters for PE diagnosis. We tested two cutoff values: (1) using PR ≥0.70, obtained A: 88.72%, S: 81.95%, and Sp: 95.48% and (2) using PR ≥0.75, and A: 86.24%, S: 74.43%, and Sp: 99.24%. By adopting P2 ≥ 21.5 cm/s, we obtained A: 87.59%, S: 84.96%, and Sp: 90.22% and when the cutoff point was P2 ≥ 22 cm/s, there was a slight decrease in A to 86.46% and S to 81.20%, with Sp: 91.89.3%.

CONCLUSION

Ophthalmic artery Doppler demonstrated to be an effective and high-performance imaging method for the diagnosis of PE and the indexes P2 and PR demonstrated superior accuracy to the other Doppler parameters assessed. Higher performance occurred when the cutoff values with greater specificity were adopted, PR ≥ 0.75 and P2 ≥ 22 cm/s, considering that the proposed OA Doppler is to be a complementary method for preeclampsia.

A sex specific approach of ophthalmic and middle cerebral arteries Doppler in smokers

Vascular dysfunctions can progress and lead to stroke and cardiovascular disease, especially in smokers. The presence of particular vascular changes according to sex has been described and they can be identified by the Doppler method. This study evaluated Doppler velocimetry parameters of the Ophthalmic Artery (OA) and the Middle Cerebral Artery (MCA) according to sex in smokers regarding a non-smoker group. This cross-sectional observational study included 178 subjects: 93 women and 85 men. Doppler parameters were assessed in OA and MCA. Student's t-test was used, with p < 0.05. There were no significant differences in OA and MCA Doppler velocimetry data between male non-smokers and smokers. However, female smokers presented several differences compared with non-smokers: lower pulsatility index (PI) and higher peak ratio in OA, and higher PI and resistance index and lower end diastolic velocity in MCA. There were different brain vascular waveforms in the group of female smokers compared with non-smokers. Cigarette smoking also led to opposite arterial patterns in OA and MCA in the female group, with signs of falling impedance in OA and increased impedance in MCA. An individualized approach regarding arterial changes according to sex is desirable.

PLACENTAL HEMODYNAMIC ASSESSMENT IN WOMEN WITH SEVERE PREECLAMPSIA IN SECOND- AND THIRD-TRIMESTER PREGNANCY BY 3D POWER QUANTITATIVE DOPPLER ULTRASOUND

Objective: The present study analyzed the fetal–placental hemodynamic parameters in women with severe preeclampsia in second- and third-trimester pregnancy with a view to developing effective predictive indicators for preeclampsia and providing support for the prenatal clinical treatment of preeclampsia. Materials and Methods: From January 2015 to January 2019, 160 pregnant women diagnosed with severe preeclampsia at Xiangyang First People’s Hospital were recruited as the study group. The diagnostic criteria for preeclampsia were in accordance with the guidelines of the International Society for the Study of Hypertension in Pregnancy (ISSHP). A sample of 160 healthy pregnant women with normal blood pressure were selected as the control group. The GE Voluson E8 and E10 four-dimensional (4D) ultrasonic diagnostic instruments and the three-dimensional (3D) power Doppler in angio-quantitative mode were used to measure the hemodynamic parameters of the placenta, left uterine artery (LUA), right uterine artery (RUA), middle cerebral artery (MCA), umbilical artery (UA), and ductus venosus (DV) in the two groups. The above parameters were analyzed statistically using SPSS 22.0. Results: The systolic/diastolic velocity ratio (S/D), pulsatility index (PI), and resistance index (RI) of the MCA in the study group were lower than those of normal subjects of the same gestational age (P < 0.05). These parameters in the UA were higher in the study group than those in normal subjects (P < 0.05). The ratios between the peak ventricular systolic velocity and the peak atrial systolic velocity (S/A), pulsatility index for the vein (PIV), pre-load index (PLI), and peak velocity index for the vein (PVIV) in the DV were significantly different between the study and normal groups (P < 0.05). The placental vascularization index (VI), flow index (FI), and vascularization flow index (VFI) were lower in the study group than those in normal subjects of the same gestational age (P < 0.05). There were good correlations between VI, VFI and RUA, PI, with correlation coefficients of −0.697 and −0.702, respectively. FI was the indicator that had the highest diagnostic efficacy for severe preeclampsia. The predictive sensitivity of the FI with a cut-off value of 34.92 was 96.3%, and the corresponding specificity was 86.9%. Conclusions: Placental FI had the highest predictive efficacy for severe preeclampsia and provides a reliable quantitative indicator and data support for preeclampsia management. 3D power quantitative Doppler ultrasound provides a novel avenue for the study of severe preeclampsia.

Predictive value of ophthalmic artery Doppler velocimetry in relation to hypertensive disorders of pregnancy

PURPOSE

To test the predictive value of ophthalmic artery (OA) Doppler velocimetry in relation to the occurrence of hypertensive disorders of pregnancy (HDP).

METHODS

We compared, by analysis of variance, the values of seven OA Doppler variables (peak systolic velocity, second systolic peak velocity [P2], mean velocity, end diastolic velocity, resistance index [RI], pulsatility index [PI], and peak ratio) of 31 women with preeclampsia and 33 women with gestational hypertension vs those of 227 women without HDP. The prognostic value of these variables in relation to the occurrence of HDP was evaluated by the area under the curve (AUC) receiver operating characteristic curve.

RESULTS

All OA Doppler variables except RI and PI showed significant (P < .5) differences between groups. After adjustment for confounders, only P2 was an independent predictor of HDP (P < .001), with an AUC of 0.76. The best cut-off point for predicting HDP was P2 ≥ 21.4 cm/s, with sensitivity 69%, specificity 78%, positive likelihood ratio 3.1, negative likelihood ratio 0.4, positive predictive value 47%, and negative predictive value 90%. P2 improved the predictive ability of a model based on clinical variables, incrementing AUC from 0.77 to 0.84 in the final model containing clinical and Doppler variables.

CONCLUSION

The elevation of OA P2 in the second trimester of pregnancy is an independent predictor of hypertensive disorders, and improves the discriminatory ability of clinical markers.