Arterial stiffness and dipper/nondipper blood pressure status in women with preeclampsia

Photoplethysmography and Heart Rate Variability for the Diagnosis of Preeclampsia

BACKGROUND

The goal of this study was to determine a set of timing, shape, and statistical features available through noninvasive monitoring of maternal electrocardiogram and photoplethysmography that identifies preeclamptic patients.

METHODS

Pregnant women admitted to Labor and Delivery were monitored with pulse oximetry and electrocardiogram for 30 minutes. Photoplethysmogram features and heart rate variability were extracted from each data set and applied to a sequential feature selection algorithm to discriminate women with preeclampsia with severe features, from normotensive and hypertensive controls. The classification boundary was chosen to minimize the expected misclassification cost. The prior probabilities of the misclassification costs were assumed to be equal.

RESULTS

Thirty-seven patients with clinically diagnosed preeclampsia with severe features were compared with 43 normotensive controls; all were in early labor or beginning induction. Six variables were used in the final model. The area under the receiver operating characteristic curve was 0.907 (standard error [SE] = 0.004) (sensitivity 78.2% [SE = 0.3%], specificity 89.9% [SE = 0.1%]) with a positive predictive value of 0.883 (SE = 0.001). Twenty-eight subjects with chronic or gestational hypertension were compared with the same preeclampsia group, generating a model with 5 features with an area under the curve of 0.795 (SE = 0.007; sensitivity 79.0% [SE = 0.2%], specificity 68.7% [SE = 0.4%]), and a positive predictive value of 0.799 (SE = 0.002).

CONCLUSIONS

Vascular parameters, as assessed noninvasively by photoplethysmography and heart rate variability, may have a role in screening women suspected of having preeclampsia, particularly in areas with limited resources.

Patterns of maternal vascular remodeling and responsiveness in early- versus late-onset preeclampsia

OBJECTIVE

We sought to assess vascular structure and function in early- and late-onset preeclampsia (PE) at the time of diagnosis.

STUDY DESIGN

We evaluated 100 PE cases subdivided into 50 early- and 50 late-onset cases according to gestational age at onset (</>34 weeks), and 100 controls paired by maternal age and gestational age at scan with cases. Carotid intima-media thickness (IMT), distensibility, and circumferential wall stress together with inferior vena cava (IVC) collapsibility were assessed by ultrasound.

RESULTS

Early PE was characterized by increased carotid IMT diameters, and arterial stiffness with no significant changes in IVC parameters as compared to normotensive pregnancies. Late PE was characterized by significantly increased carotid IMT and lumen diameters as compared to controls while arterial stiffness, as expressed by distensibility, did not provide pronounced changes. A significant decrease of IVC collapsibility index was also observed in late PE as compared to controls.

CONCLUSION

The current data suggest that distinct vascular adaptations in early and late PE could reflect different pathophysiologic mechanisms. Future studies are warranted to further assess the complex etiologies and clinical expressions of the 2 entities.

The association between preeclampsia and arterial stiffness

A systematic review and meta-analysis was conducted using MEDLINE, EMBASE, and the Cochrane Library to investigate the association between preeclampsia and arterial stiffness. Twenty-three relevant studies were included. A significant increase in all arterial stiffness indices combined was observed in women with preeclampsia vs. women with normotensive pregnancies [standardized mean difference 1.62, 95% confidence interval (CI) 0.73-2.50]; carotid-femoral pulse wave velocity (cfPWV) and augmentation index (AIx) were also significantly increased (weighted mean difference, WMDcfPWV 1.04, 95% CI 0.34-1.74; WMDAIx 15.10, 95% CI 5.08-25.11), whereas carotid-radial PWV (crPWV) increase did not reach significance (WMDcrPWV 0.99, 95% CI -0.07 to 2.05). Significant increases in arterial stiffness measurements were noted in women with preeclampsia compared with those with gestational hypertension. Arterial stiffness measurements may also be useful in predicting preeclampsia and may play a role in the increased risk of future cardiovascular complications seen in women with a history of preeclampsia.