Added prognostic value of Doppler ultrasound for adverse perinatal outcomes: A pooled analysis of three cohort studies.

BACKGROUND: Fetal growth restriction (FGR) is an obstetric complication associated with adverse perinatal outcomes. Doppler ultrasound can improve perinatal outcomes through monitoring at-risk fetuses and helping time delivery. AIM: To investigate the prognostic value of different Doppler ultrasound measurements for adverse perinatal outcomes. MATERIALS: Individual participant data. METHODS: We performed a pooled analysis on individual participant data. We compared six prognostic models using multilevel logistic regression, where each subsequent model added a new variable to a base model that included maternal characteristics. Estimated fetal weight (EFW) and four Doppler ultrasound measurements were added in turn: umbilical artery pulsatility index (UA PI), middle cerebral artery pulsatility index (MCA PI), cerebroplacental ratio (CPR), and mean uterine artery pulsatility index (mUtA PI). The primary outcome was a composite adverse perinatal outcome, defined as perinatal mortality, emergency caesarean delivery for fetal distress, or neonatal admission. Discriminative ability was quantified with area under the curve (AUC). RESULTS: Three data sets (N = 3284) were included. Overall, the model that included EFW and UA PI improved AUC from 0.650 (95% CI 0.624-0.676) to 0.673 (95% CI 0.646-0.700). Adding more ultrasound measurements did not improve further the discriminative ability. In subgroup analysis, the addition of EFW and UA PI improved AUC in both preterm (AUC from 0.711 to 0.795) and small for gestational age pregnancies (AUC from 0.729 to 0.770), but they did not improve the models in term delivery or normal growth subgroups. CONCLUSIONS: Umbilical artery pulsatility index added prognostic value for adverse perinatal outcomes to the already available information, but the combination of other Doppler ultrasound measurements (MCA PI, CPR or UtA PI) did not improve further prognostic performance.

Publication bias may exist among prognostic accuracy studies of middle cerebral artery Doppler ultrasound.

OBJECTIVES: The objective of this study was to assess if there is evidence of publication bias in prognostic accuracy studies of middle cerebral artery (MCA) or cerebroplacental ratio (CPR) for adverse perinatal outcome. STUDY DESIGN AND SETTING: We queried PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov and searched abstract books of five perinatal conferences (1989-2017). We included prognostic accuracy studies on MCA and/or CPR. Highest reported accuracy estimates, sample size, study design, and conclusion positivity were extracted and compared. RESULTS: We included 127 full-text articles and 51 conference abstracts, 29 of which had not been reported as full-text article. In conference abstracts not reported in full, median negative predictive value was significantly lower compared to full-text articles (0.79 [interquartile range 0.67-0.97] vs. 0.95 [0.89-0.99]; P < 0.001). No significant difference was identified for positive predictive value (0.62 vs. 0.59; P = 0.827), sensitivity (0.67 vs. 0.71; P = 0.159), and specificity (0.86 vs. 0.86; P = 0.632). Study design differed significantly as well (P = 0.030), with fewer prospective studies in conference abstracts not reported in full compared to full-text articles (28% vs. 54%). We found no significant differences in sample size or conclusion positivity. CONCLUSION: Possibly, a publication bias in previously published meta-analyses of MCA and CPR has led to overly generous estimates of prognostic performance.

Women's experiences of monitoring the small-for-gestational age fetus by ultrasound: A qualitative study.

OBJECTIVE: To explore experiences among pregnant women diagnosed with a small-for-gestational age (SGA) fetus, and monitored by frequent ultrasounds. METHODS: We performed a qualitative study at the outpatient clinic of the Gynecology and Obstetrics department of a large academic hospital in Amsterdam. Semi-structured interviews were conducted with fifteen women, diagnosed with an SGA fetus during their pregnancy and having had at least two monitoring ultrasounds since. Themes were identified following analysis of the interview transcripts. RESULTS: Most women experienced the frequent ultrasounds as a source of support providing comfort and a feeling of safety. It was considered necessary, in the best interest of the baby, which outweighed the discomfort caused by having to come to the hospital frequently. Women described anxiety building up prior to each ultrasound, but feeling reassured and relieved afterwards. During the ultrasound a continuous explanation was preferred, which provided confirmation and a feeling of security. Women identified the uncertainty of SGA's cause and prognosis as one of the biggest challenges to cope with, for which they used different strategies. Many women expressed a need for more detailed information and counselling, including non-medical aspects of pregnancy and delivery as well. Lastly, many women reported that seeing different doctors negatively influenced the perceived quality of care. CONCLUSIONS: In general, women in this study were satisfied with the ultrasounds for their small-for-gestational age pregnancies. However, women expressed a need for additional information to help cope with a feeling of uncertainty regarding cause and prognosis. Their medical team should preferably provide this in a consistent and continuous manner.

Doppler measurements of both umbilical arteries do not improve predictive value for adverse perinatal outcomes in small-for-gestational age fetuses.

OBJECTIVE: To assess agreement of Doppler ultrasound measurements of the two umbilical arteries in small-for gestational age (SGA) fetuses, and to compare discriminative ability between the two arteries for adverse perinatal outcome. STUDY DESIGN: We analysed a prospective cohort of singleton SGA pregnancies, in which the pulsatility index (PI) of both umbilical arteries was standardly measured by Doppler ultrasound in the free-floating umbilical cord. The outcome of interest was a composite adverse outcome, defined as perinatal death, Apgar score <7 at 5 min, cesarean section for fetal distress, and neonatal intensive care unit admission. RESULTS: A total of 531 measurements were performed in 124 patients. Mean absolute difference between PI measured in the two umbilical arteries was 0.14 (95% CI: 0.12 to 0.15), showing good agreement with an ICC of 0.830 (95% CI: 0.801 to 0.854). Perinatal outcomes were available for 101 patients, of which 48 patients (48%) had a composite adverse perinatal outcome. We found no significant differences between AUCs for prediction of an adverse outcome based on lowest, highest and mean PI values in the two umbilical arteries (AUCs = 0.75, 0.74, 0.75 with p = 0.91). As a comparison, the AUC of a PI value obtained in a single, randomly selected umbilical artery was 0.74. CONCLUSION: The two umbilical arteries show good agreement in terms of their PI values in the free-floating umbilical cord, and do not differ in terms of their discriminative ability for adverse perinatal outcome in SGA fetuses. We found no evidence of an added value of standard Doppler measurement of both umbilical arteries.

Influence of the vectorcardiogram synthesis matrix on the power of the electrocardiogram-derived spatial QRS-T angle to predict arrhythmias in patients with ischemic heart disease and systolic left ventricular dysfunction.

BACKGROUND AND PURPOSE: Several studies have demonstrated that the spatial mean QRS-T angle (SA) predicts cardiac events and mortality. Spatial mean QRS-T angle is a vectorcardiographic variable. Because in clinical practice, 12-lead standard electrocardiograms (ECGs) are recorded rather than vectorcardiograms (VCGs) according to Frank, VCGs are commonly obtained by synthesizing them from 12-lead ECGs, by using a VCG synthesis matrix. Hence, the thus computed SA is an estimate of the real SA measured in the Frank VCG. Recent studies have shown that Kors VCG synthesis matrix yields better estimates of SA than the inverse Dower VCG synthesis matrix. Our current study aims to compare the predictive power of these SA variants for the occurrence of potentially lethal arrhythmias. METHODS: The study group consisted of patients with ischemic heart disease and left ventricular systolic dysfunction who received an implantable cardioverter-defibrillator (ICD) for primary prevention. During follow-up, the occurrence of appropriate device therapy (occurrence of ventricular arrhythmia) was noted. Alternative SAs were computed in VCGs synthesized from standard 12-lead ECGs by using either the inverse Dower matrix (SA-Dower) or the Kors matrix (SA-Kors). Comparison of the predictive power of SA-Dower and SA- Kors was performed by receiver operating characteristic analysis, by Kaplan-Meier analysis, and by univariate and multivariate Cox regression analysis, using every 10th percentile of SA as a cutoff value. RESULTS: The study group consisted of 412 patients (361 men; mean ± SD age 63 ± 11 years), in which 56 patients had appropriate ICD therapy during follow-up. Receiver operating characteristic analysis revealed that the area under the curve of SA-Kors was significantly larger than area under the curve of SA-Dower (0.646 vs 0.607, P = .043). The discriminative power of SA-Kors for the absence/presence of appropriate ICD therapy in patients during follow-up was generally superior to SA-Dower over a wide range of cutoff values in the Kaplan-Meier analysis and generally yielded stronger hazard ratios in the univariate and multivariate Cox regression analyses. CONCLUSION: If there is no specific reason to use the inverse Dower matrix, VCG synthesis from standard 12-lead ECGs should preferably be done by using the Kors matrix. It is likely to assume that already published studies in which the predictive value of SA-Dower was demonstrated would yield stronger results if the SA-Dower angles were substituted by SA-Kors angles.

The spatial QRS-T angle in the Frank vectorcardiogram: accuracy of estimates derived from the 12-lead electrocardiogram.

BACKGROUND AND PURPOSE: The spatial QRS-T angle (SA), a predictor of sudden cardiac death, is a vectorcardiographic variable. Gold standard vertorcardiograms (VCGs) are recorded by using the Frank electrode positions. However, with the commonly available 12-lead ECG, VCGs must be synthesized by matrix multiplication (inverse Dower matrix/Kors matrix). Alternatively, Rautaharju proposed a method to calculate SA directly from the 12-lead ECG. Neither spatial angles computed by using the inverse Dower matrix (SA-D) nor by using the Kors matrix (SA-K) or by using Rautaharju's method (SA-R) have been validated with regard to the spatial angles as directly measured in the Frank VCG (SA-F). Our present study aimed to perform this essential validation. METHODS: We analyzed SAs in 1220 simultaneously recorded 12-lead ECGs and VCGs, in all data, in SA-F-based tertiles, and after stratification according to pathology or sex. RESULTS: Linear regression of SA-K, SA-D, and SA-R on SA-F yielded offsets of 0.01 degree, 20.3 degrees, and 28.3 degrees and slopes of 0.96, 0.86, and 0.79, respectively. The bias of SA-K with respect to SA-F (mean +/- SD, -3.2 degrees +/- 13.9 degrees) was significantly (P < .001) smaller than the bias of both SA-D and SA-R with respect to SA-F (8.0 degrees +/- 18.6 degrees and 9.8 degrees +/- 24.6 degrees, respectively); tertile analysis showed a much more homogeneous behavior of the bias in SA-K than of both the bias in SA-D and in SA-R. In pathologic ECGs, there was no significant bias in SA-K; bias in men and women did not differ. CONCLUSION: SA-K resembled SA-F best. In general, when there is no specific reason either to synthesize VCGs with the inverse Dower matrix or to calculate the spatial QRS-T angle with Rautaharju's method, it seems prudent to use the Kors matrix.