The 2017 American College of Cardiology and American Heart Association blood pressure categories in the second half of pregnancy-a systematic review of their association with adverse pregnancy outcomes

The association between 2017 American College of Cardiology/American Heart Association guideline for hypertension and neonatal outcomes in Kenya: a retrospective study

BACKGROUND

Hypertension in pregnancy serves to screen for adverse perinatal outcomes. In 2017, the American College of Cardiology and American Heart Association recommended a new blood pressure category with lower hypertension thresholds, excluding pregnancy. This study aimed to explore the association between the 2017 redefined blood pressure categories in pregnancy and neonatal outcomes such as preterm birth and low birth weight.

METHODS

This retrospective study used electronic records of the Maternal and Child Health Handbook registered by the Women and Infant Registration System. All women who had at least one antenatal care visit and delivery between January 2017 and April 2020 and between May and December 2022 were included in the study. A birth of less than 37 weeks was defined as preterm delivery. LBW was identified based on a newborn's birthweight of less than 2500 g. The maximum blood pressure across all antenatal care visits was classified based on the newly recommended criteria. A generalized linear model with binomial distribution and logit link function was used to evaluate the association between new blood pressure categories and neonatal outcomes at different levels of health facilities.

RESULTS

We analyzed data from 825 women. Of these, the prevalence was 13.7% for elevated blood pressure, 15.2% for stage 1 hypertension, 4.5% for non-severe stage 2 hypertension and 1.2% for severe stage 2 hypertension. For lower-level facilities, no significant associations were identified between the redefined blood pressure category and preterm birth or low birthweight. At higher-level facilities, preterm birth was only significantly associated with severe stage 2 hypertension (adjusted odds ratio:10.94; 95% confidence interval:1.08-110.93; P = 0.04) and low birthweight showed no association with the redefined category.

CONCLUSION

This study revealed no association between redefined lower blood pressure threshold and preterm birth and low birthweight in under-resourced settings. However, previous studies in well-resourced countries with larger sample sizes also reported a significant association. Therefore, further investigations are required.

Blood pressure cutoffs at 11-13 weeks of gestation and risk of preeclampsia

BACKGROUND

A parallel has been drawn between first-trimester placental vascular maturation and maternal cardiovascular adaptations, including blood pressure. Although 140/90 mm Hg is well-accepted as the threshold for chronic hypertension in the general obstetric population in early pregnancy, a different threshold could apply to stratify the risk of adverse outcomes, such as preeclampsia. This could have implications for interventions, such as the threshold for initiation of antihypertensive therapy and the target blood pressure level.

OBJECTIVE

We evaluated the relationship between various blood pressure cutoffs at 11-13 weeks of gestation and the development of preeclampsia, overall and according to key maternal characteristics.

STUDY DESIGN

This secondary analysis was of data from a prospective nonintervention cohort study of singleton pregnancies delivering at ≥24 weeks, without major anomalies, at 2 United Kingdom maternity hospitals, 2006-2020. Blood pressure at 11-13 weeks of gestation was classified according to American College of Cardiology/American Heart Association categories (mm Hg) as (1) normal blood pressure (systolic <120 and diastolic <80), (2) elevated blood pressure (systolic ≥120 and diastolic <80), stage 1 hypertension (systolic ≥130 or diastolic 80-89), and stage 2 hypertension (systolic ≥140 or diastolic ≥90). For blood pressure category thresholds and the outcome of preeclampsia, the following were calculated overall and across maternal age, body mass index, ethnicity, method of conception, and previous pregnancy history: detection rate, screen-positive rate, and positive and negative likelihood ratios, with 95% confidence intervals. A P value of <.05 was considered significant.

RESULTS

There were 137,458 pregnancies screened at 11-13 weeks of gestation. The population was ethnically diverse, with 15.9% of Black ethnicity, 6.7% of South or East Asian ethnicity, and 2.7% of mixed ethnicity, with the remainder of White ethnicity. Compared with normal blood pressure, stage 2 hypertension was associated with both preterm preeclampsia (0.3% to 4.9%) and term preeclampsia (1.0% to 8.3%). A blood pressure threshold of 140/90 mm Hg was good at identifying women at increased risk of preeclampsia overall (positive likelihood ratio, 5.61 [95% confidence interval, 5.14-6.11]) and across maternal characteristics, compared with elevated blood pressure (positive likelihood ratio, 1.70 [95% confidence interval, 1.63-1.77]) and stage 1 hypertension (positive likelihood ratio, 2.68 [95% confidence interval, 2.58-2.77]). There were 2 exceptions: a blood pressure threshold of 130/80 mm Hg was better for the 2.1% of women with body mass index <18.5 kg/m2 (positive likelihood ratio, 5.13 [95% confidence interval, 3.22-8.16]), and a threshold of 135/85 mm Hg better for the 50.4% of parous women without a history of preeclampsia (positive likelihood ratio, 5.24, [95% confidence interval, 4.77-5.77]). There was no blood pressure threshold below which reassurance could be provided against the development of preeclampsia (all-negative likelihood ratios ≥0.20).

CONCLUSION

The traditional blood pressure threshold of 140/90 mm Hg performs well to identify women at increased risk of preeclampsia. Women who are underweight or parous with no prior history of preeclampsia may be better identified by lower thresholds; however, a randomized trial would be necessary to determine any benefits of such an approach if antihypertensive therapy were also administered at this threshold. No blood pressure threshold is reassured against the development of preeclampsia, regardless of maternal characteristics.

Diagnostic properties of differing BP thresholds for adverse pregnancy outcomes in standard-risk nulliparous women: A secondary analysis of SCOPE cohort data

BACKGROUND

In 2017, the American College of Cardiology and American Heart Association (ACC/AHA) lowered blood pressure (BP) thresholds to define hypertension in adults outside pregnancy. If used in pregnancy, these lower thresholds may identify women at increased risk of adverse outcomes, which would be particularly useful to risk-stratify nulliparous women. In this secondary analysis of the SCOPE cohort, we asked whether, among standard-risk nulliparous women, the ACC/AHA BP categories could identify women at increased risk for adverse outcomes.

METHODS AND FINDINGS

Included were pregnancies in the international SCOPE cohort with birth at ≥20 weeks' gestation, 2004 to 2008. Women were mostly of white ethnicity, in their 20s, and of normal-to-overweight body mass index (BMI). Excluded were pregnancies ending in fetal loss at <20 weeks' gestation, and those terminated at any point in pregnancy. Women were categorized by highest BP during pregnancy, using ACC/AHA criteria: normal (BP <120/80 mmHg), "Elevated BP" (BP 120 to 129 mmHg/<80 mmHg), "Stage-1 hypertension" (systolic BP [sBP] 130 to 139 mmHg or diastolic BP [dBP] 80 to 89 mmHg), and "Stage-2 hypertension" that was non-severe (sBP 140 to 159 mmHg or dBP 90 to 109 mmHg) or severe (sBP ≥160 mmHg or dBP ≥110 mmHg). Primary outcomes were preterm birth (PTB), low birthweight, postpartum hemorrhage, and neonatal care admission. Adjusted relative risks (aRRs) and diagnostic test properties were calculated for each outcome, according to: each BP category (versus "normal"), and using the lower limit of each BP category as a cut-off. RRs were adjusted for maternal age, BMI, smoking, ethnicity, and alcohol use. Of 5,628 women in SCOPE, 5,597 were included in this analysis. When compared with normotension, severe "Stage 2 hypertension" was associated with PTB (24.0% versus 5.3%; aRR 4.88, 95% confidence interval, CI [3.46 to 6.88]), birthweight <10th centile (24.4% versus 8.8%; aRR 2.70 [2.00 to 3.65]), and neonatal unit admission (32.9% versus 8.9%; aRR 3.40 [2.59 to 4.46]). When compared with normotension, non-severe "Stage 2 hypertension" was associated with birthweight <10th centile (16.1% versus 8.8%; aRR 1.82 [1.45 to 2.29]) and neonatal unit admission (15.4% versus 8.9%; aRR 1.65 [1.31 to 2.07]), but no association with adverse outcomes was seen with BP categories below "Stage 2 hypertension." When each BP category was assessed as a threshold for diagnosis of abnormal BP (compared with BP values below), only severe "Stage 2 hypertension" had a useful (good) likelihood ratio (LR) of 5.09 (95% CI [3.84 to 6.75]) for PTB. No BP threshold could rule-out adverse outcomes (i.e., had a negative LR <0.2). Limitations of our analysis include lack of ethnic diversity and use of values from clinical notes for BP within 2 weeks before birth. This study was limited by: its retrospective nature, not all women having BP recorded at all visits, and the lack of detail about some outcomes.

CONCLUSIONS

In this study, we observed that 2017 ACC/AHA BP categories demonstrated a similar pattern of association and diagnostic test properties in nulliparous women, as seen in the general obstetric population. BP thresholds below the currently used "Stage 2 hypertension" were not associated with PTB, low birthweight, postpartum hemorrhage, or neonatal unit admission. This study does not support implementation of lower BP values as abnormal in nulliparous pregnant women.

2024 Guideline for the Primary Prevention of Stroke: A Guideline From the American Heart Association/American Stroke Association

AIM

The "2024 Guideline for the Primary Prevention of Stroke" replaces the 2014 "Guidelines for the Primary Prevention of Stroke." This updated guideline is intended to be a resource for clinicians to use to guide various prevention strategies for individuals with no history of stroke.

METHODS

A comprehensive search for literature published since the 2014 guideline; derived from research involving human participants published in English; and indexed in MEDLINE, PubMed, Cochrane Library, and other selected and relevant databases was conducted between May and November 2023. Other documents on related subject matter previously published by the American Heart Association were also reviewed.

STRUCTURE

Ischemic and hemorrhagic strokes lead to significant disability but, most important, are preventable. The 2024 primary prevention of stroke guideline provides recommendations based on current evidence for strategies to prevent stroke throughout the life span. These recommendations align with the American Heart Association's Life's Essential 8 for optimizing cardiovascular and brain health, in addition to preventing incident stroke. We also have added sex-specific recommendations for screening and prevention of stroke, which are new compared with the 2014 guideline. Many recommendations for similar risk factor prevention were updated, new topics were reviewed, and recommendations were created when supported by sufficient-quality published data.

Pregnancy Outcomes in Women Who Developed Elevated Blood Pressure and Stage I Hypertension after 20 Weeks, Gestation

OBJECTIVE

 The American College of Obstetrics threshold for hypertension (≥140/90 mm Hg) differs from those of the American College of Cardiology (ACC) and the American Heart Association (AHA). It is unknown if ACC/AHA hypertension levels are associated with adverse pregnancy outcomes (APOs) after 20 weeks gestation. The purpose of this study is to analyze APOs in women with blood pressure (BP) in the elevated or stage 1 range after 20 weeks gestation.

STUDY DESIGN

 This was a secondary analysis of the nuMoM2b prospective cohort study of 10,038 nulliparous, singleton pregnancies between 2010 and 2014. BP was measured at three visits during the pregnancy using a standard protocol. Women without medical comorbidities, with normal BP by ACC/AHA guidelines (systolic BP [SBP] < 120 and diastolic BP [DBP] < 80 mm Hg) up to 22 weeks, were included. Exposure was BP between 22 and 29 weeks gestation: normal (SBP < 120 and DBP < 80 mm Hg), elevated (SBP: 120-129 and DBP < 80 mm Hg), and stage 1 (SBP: 130-139 or DBP: 80-89 mm Hg). The primary outcome was hypertensive disorder of pregnancy (HDP) at delivery. Secondary outcomes included fetal growth restriction (FGR), placental abruption, preterm delivery, and cesarean delivery. Multivariable-adjusted odds ratio (aORs) and 95% confidence intervals (CIs) were estimated using logistic regression models.

RESULTS

 Of 4,460 patients that met inclusion criteria, 3,832 (85.9%) had BP in the normal range, 408 (9.1%) in elevated, and 220 (4.9%) in stage 1 range between 22 and 29 weeks. The likelihood of HDP was significantly higher in women with elevated BP (aOR: 1.71, 95%CI: 1.18,2.48), and stage 1 BP (aOR: 2.79, 95%CI: 1.84,4.23) compared to normal BP (p < 0.001). Stage 1 BP had twice odds of FGR (aOR: 2.33, 95%CI: 1.22,4.47) and elevated BP had three times odds of placental abruption (aOR: 3.03; 95%CI: 1.24,7.39).

CONCLUSION

 Elevated or stage 1 BP >20 weeks of pregnancy are associated with HDP, FGR, and placental abruption.

KEY POINTS

· Elevated and stage 1 BP increases risk for HDP.. · Elevated BP increases risk for placental abruption.. · Stage 1 BP increases risk for FGR..

Hypertensive disorders of pregnancy and stroke: a univariate and multivariate Mendelian randomization study

Background

Hypertensive disorders of pregnancy (HDP) are associated with an increased risk of stroke later in life in multiparous women. However, causality of these associations remains unclear. This study employed 2-sample univariate and multivariate Mendelian randomization (MR) to assess the causal connection between HDP and stroke.

Methods

Genetic variants for HDP and two subtypes were identified from recent large-scale genome-wide association studies and the FinnGen consortium. Stroke summary data were obtained from the MEGASTROKE consortium. The primary analytical approach for univariate MR was the inverse variance weighting method. Sensitivity analyses incorporated methods such as MR-Egger regression, weighted median, and maximum likelihood to ascertain the robustness of the results. Additionally, multivariable MR analyses were conducted to account for potential associative effects of hypertension and type 2 diabetes.

Results

Genetically predicted HDP was associated with a high risk of large artery atherosclerosis (odds ratio [OR]=1.50, 95% confidence interval [CI]: 1.17-1.91, P=1.13×10-3) and small vessel stroke (OR=1.29, 95% CI: 1.20-1.50, P=1.52×10-3). HDP may also correlate with ischemic stroke (OR=1.13, 95% CI: 1.04-1.23, P=4.99×10-3) and stroke (OR=1.11, 95% CI: 1.03-1.20, P=8.85×10-3). An elevated risk of small vessel stroke (OR=1.20, 95% CI: 1.01-1.43, P=3.74×10-2) and large artery atherosclerosis (OR=1.22, 95% CI: 1.01-1.47, P=4.07×10-2) may be related with genetically predicted susceptibility to gestational hypertension. Genetically predicted susceptibility to preeclampsia or eclampsia may be associated with an increased risk of stroke (OR = 1.10, 95% CI: 1.02-1.19, P = 1.16×10-2) and ischemic stroke (OR = 1.10, 95% CI: 1.02-1.20, P = 1.84×10-2). Type 2 diabetes mellitus and hypertension were identified as significant factors contributing to the association between HDP and stroke.

Conclusions

This study provides genetic evidence supporting an association between HDP and increased stroke risk bolstering HDP as a cerebrovascular risk factor.

Prevalence and associated factors of metabolic syndrome among pregnant Ethiopian women: a hospital-based cross-sectional study

Metabolic syndrome (MetS) poses a significant public health challenge globally, including in Ethiopia, with risks for both mothers and children. Unfortunately, there is limited data on MetS in pregnant Ethiopian women. This study aims to evaluate the prevalence and factors associated with MetS in this population. A cross-sectional study was conducted using a systematic random sampling technique. Data were collected through face-to-face interviews using a structured questionnaire adapted from the World Health Organization Steps Survey Tool for Non-communicable Diseases. About five ml of fasting peripheral blood samples were collected from each participant. The Beckman Coulter DXC 700 AU clinical chemistry analyzer was employed for lipid profile and glucose analysis. Subsequently, data were inputted into Epi Data and later exported to SPSS Version 20 for further analysis. Bivariable and multivariable binary logistic regression analyses were carried out, with a predefined level of statistical significance at p < 0.05. A total of 318 pregnant women were included in this study. The prevalence of MetS was 13.2% (95% CI: 9.7, 17.0) based on the American Heart Association/National Heart Lung and Blood Institute definition. The most prevalent components of MetS were elevated triglyceride levels, reduced high-density lipoprotein levels, and elevated blood pressure. Unhealthy sleep duration (AOR = 5.6, 95% CI (2.4, 13.1), p < 0.001), high daily salt intake (AOR = 4.2, 95% CI (1.8, 9.5), p = 0.001), and alcohol consumption [AOR = 4.2, 95% CI (1.6, 10.9), p = 0.003] were significantly associated with MetS. The study reported a high prevalence of MetS in pregnant Ethiopian women. Factors including alcohol, high salt intake, and sleep disturbances were associated with MetS. Policymakers might utilize this data to create targeted interventions and public health policies for MetS among pregnant women, focusing on nutrition, sleep, and alcohol consumption during pregnancy to safeguard maternal and fetal health.

Blood pressure measurement and adverse pregnancy outcomes: A cohort study testing blood pressure variability and alternatives to 140/90 mmHg

OBJECTIVE

To examine the association with adverse pregnancy outcomes of: (1) American College of Cardiology/American Heart Association blood pressure (BP) thresholds, and (2) visit-to-visit BP variability (BPV), adjusted for BP level.

DESIGN

An observational study.

SETTING

Analysis of data from the population-based UK Southampton Women's Survey (SWS).

POPULATION OR SAMPLE

3003 SWS participants.

METHODS

Generalised estimating equations were used to estimate crude and adjusted relative risks (RRs) of adverse pregnancy outcomes by BP thresholds, and by BPV (as standard deviation [SD], average real variability [ARV] and variability independent of the mean [VIM]). Likelihood ratios (LRs) were calculated to evaluate diagnostic test properties, for BP at or above a threshold, compared with those below.

MAIN OUTCOME MEASURES

Gestational hypertension, severe hypertension, pre-eclampsia, preterm birth (PTB), small-for-gestational-age (SGA) infants, neonatal intensive care unit (NICU) admission.

RESULTS

A median of 11 BP measurements were included per participant. For BP at ≥20 weeks' gestation, higher BP was associated with more adverse pregnancy outcomes; however, only BP <140/90 mmHg was a good rule-out test (negative LR <0.20) for pre-eclampsia and BP ≥140/90 mmHg a good rule-in test (positive LR >8.00) for the condition. BP ≥160/110 mmHg could rule-in PTB, SGA infants and NICU admission (positive LR >5.0). Higher BPV (by SD, ARV, or VIM) was associated with gestational hypertension, severe hypertension, pre-eclampsia, PTB, SGA and NICU admission (adjusted RRs 1.05-1.39).

CONCLUSIONS

While our findings do not support lowering the BP threshold for pregnancy hypertension, they suggest BPV could be useful to identify elevated risk of adverse outcomes.

Blood Pressure and Heart Rate Variability and the Impact on Pregnancy Outcomes: A Systematic Review

BACKGROUND

Long-term (visit-to-visit) blood pressure variability (BPV) and heart rate variability (HRV) outside pregnancy are associated with adverse cardiovascular outcomes. Given the limitations of relying solely on blood pressure level to identify pregnancies at risk, long-term (visit-to-visit) BPV or HRV may provide additional diagnostic/prognostic counsel. To address this, we conducted a systematic review to examine the association between long-term BPV and HRV in pregnancy and adverse maternal and perinatal outcomes.

METHODS AND RESULTS

Databases were searched from inception to May 2023 for studies including pregnant women, with sufficient blood pressure or heart rate measurements to calculate any chosen measure of BPV or HRV. Studies were excluded that reported short-term, not long-term, variability. Adjusted odds ratios were extracted. Eight studies (138 949 pregnancies) reporting BPV met our inclusion criteria; no study reported HRV and its association with pregnancy outcomes. BPV appeared to be higher in women with hypertension and preeclampsia specifically, compared with unselected pregnancy cohorts. Greater BPV was associated with significantly more adverse pregnancy outcomes, particularly maternal (gestational hypertension [odds ratio range, 1.40-2.15], severe hypertension [1.40-2.20]), and fetal growth (small-for-gestational-age infants [1.12-1.32] or low birth weight [1.18-1.39]). These associations were independent of mean blood pressure level. In women with hypertension, there were stronger associations with maternal outcomes but no consistent pattern for perinatal outcomes.

CONCLUSIONS

Future work should aim to confirm whether BPV could be useful for risk stratification prospectively in pregnancy, and should determine the optimal management path for those women identified at increased risk of adverse outcomes.

Perinatal Outcomes Associated With Management of Stage 1 Hypertension

OBJECTIVE

To evaluate the association between maternal blood pressure (BP) below 130/80 mm Hg compared with 130-139/80-89 mm Hg and pregnancy outcomes.

METHODS

We conducted a planned secondary analysis of CHAP (Chronic Hypertension and Pregnancy), an open label, multicenter, randomized controlled trial. Participants with mean BP below 140/90 mm Hg were grouped as below 130/80 mm Hg compared with 130-139/80-89 mm Hg by averaging postrandomization clinic BP throughout pregnancy. The primary composite outcome was preeclampsia with severe features, indicated preterm birth before 35 weeks of gestation, placental abruption, or fetal or neonatal death. The secondary outcome was small for gestational age (SGA).

RESULTS

Of 2,408 patients in CHAP, 2,096 met study criteria; 1,328 had mean BP 130-139/80-89 mm Hg and 768 had mean BP below 130/80 mm Hg. Participants with mean BP below 130/80 mm Hg were more likely to be older, on antihypertensive medication, in the active treatment arm, and to have lower BP at enrollment. Mean clinic BP below 130/80 mm Hg was associated with lower frequency of the primary outcome (16.0% vs 35.8%, adjusted relative risk 0.45; 95% CI 0.38-0.54) as well as lower risk of severe preeclampsia and indicated birth before 35 weeks of gestation. There was no association with SGA.

CONCLUSION

In pregnant patients with mild chronic hypertension, mean BP below 130/80 mm Hg was associated with improved pregnancy outcomes without increased risk of SGA.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov , NCT02299414.