Women with Preterm Birth Have Evidence of Subclinical Atherosclerosis a Decade After Delivery

Pregnancy complications and long-term risk of cardiovascular events in women with structural heart disease

BACKGROUND

To determine the frequency of pregnancy complications and their association with the risk of cardiovascular outcomes in women with structural heart disease (SHD).

METHODS

This nationwide registry-based cohort study included women in Sweden with SHD (pulmonary arterial hypertension, congenital heart disease or acquired valvular heart disease) with singleton births registered in the national Medical Birth Register (MBR) between 1973 and 2014. Exposures were pregnancy complications; pre-eclampsia/gestational hypertension (PE/gHT), preterm birth and small for gestational age (SGA) collected from MBR. The outcomes were cardiovascular mortality and hospitalisations defined from the Cause of Death Register and the National Patient Register. Cox regression models were performed with time-dependent covariates, to determine the possible association of pregnancy complications for cardiovascular outcomes.

RESULTS

Among the total of 2 134 239 women included in the MBR, 2554 women with 5568 singleton births were affected by SHD. Women without SHD (N=2 131 685) were used as a reference group. PE/gHT affected 5.8% of pregnancies, preterm birth 9.7% and SGA 2.8%. Preterm birth (adjusted HR, aHR 1.91 (95% CI 1.38 to 2.64)) was associated with an increased risk of maternal all-cause mortality. PE/gHT (aHR 1.64 (95% CI 1.18 to 2.29)) and preterm birth (aHR 1.56 (95% CI 1.19 to 2.04)) were associated with an increased risk of hospitalisations for atherosclerotic CVD.

CONCLUSIONS

Pregnancy complications were frequent in women with SHD. With a median follow-up time of 22 years, preterm birth was associated with a higher risk of cardiovascular mortality, and PE/gHT and preterm birth were associated with cardiovascular morbidity. In women with SHD, pregnancy complications may provide additional information for the risk assessment of future cardiovascular outcomes.

Update on sex specific risk factors in cardiovascular disease

Cardiovascular disease (CVD) is the leading cause of death worldwide and accounts for roughly 1 in 5 deaths in the United States. Women in particular face significant disparities in their cardiovascular care when compared to men, both in the diagnosis and treatment of CVD. Sex differences exist in the prevalence and effect of cardiovascular risk factors. For example, women with history of traditional cardiovascular risk factors including hypertension, tobacco use, and diabetes carry a higher risk of major cardiovascular events and mortality when compared to men. These discrepancies in terms of the relative risk of CVD when traditional risk factors are present appear to explain some, but not all, of the observed differences among men and women. Sex-specific cardiovascular disease research-from identification, risk stratification, and treatment-has received increasing recognition in recent years, highlighting the current underestimated association between CVD and a woman's obstetric and reproductive history. In this comprehensive review, sex-specific risk factors unique to women including adverse pregnancy outcomes (APO), such as hypertensive disorders of pregnancy (HDP), gestational diabetes mellitus, preterm delivery, and newborn size for gestational age, as well as premature menarche, menopause and vasomotor symptoms, polycystic ovarian syndrome (PCOS), and infertility will be discussed in full detail and their association with CVD risk. Additional entities including spontaneous coronary artery dissection (SCAD), coronary microvascular disease (CMD), systemic autoimmune disorders, and mental and behavioral health will also be discussed in terms of their prevalence among women and their association with CVD. In this comprehensive review, we will also provide clinicians with a guide to address current knowledge gaps including implementation of a sex-specific patient questionnaire to allow for appropriate risk assessment, stratification, and prevention of CVD in women.

Isotemporal Associations of Device-Measured Sedentary Time and Physical Activity with Cardiac-Autonomic Regulation in Previously Pregnant Women

BACKGROUND

High sedentary time (ST) and low physical activity may increase cardiovascular risk, potentially though cardiac-autonomic dysregulation. This study investigated associations of statistically exchanging device-measured ST and physical activity with measures of cardiac-autonomic regulation in previously pregnant women.

METHOD

This cross-sectional, secondary analysis included 286 women (age = 32.6 ± 5.7 years; 68% white) measured 7-15 years after delivery. ST and light (LPA), moderate (MPA), vigorous (VPA), and moderate-to-vigorous (MVPA) intensity physical activity were measured by ActiGraph GT3X. ST was further partitioned into long (≥ 30 min) and short (< 30 min) bouts. MVPA was also partitioned into long (≥ 10 min) and short (< 10 min) bouts. Cardiac-autonomic regulation was assessed by heart rate variability (HRV) (resting heart rate, natural log transformed standard deviation of normal R-R intervals [lnSDNN], natural log-transformed root mean square of successive differences [lnRMSSD]) from a 5-min seated ECG. Progressive isotemporal substitution models adjusted for confounders. Sensitivity analyses removed women with related underlying medical conditions and who did not meet respiration rate criteria.

RESULTS

Initial analyses found no significant associations with HRV when exchanging 30 min of ST and physical activity (p > 0.05). Yet, replacing long- and short-bout ST with 30 min of long-bout MVPA yielded significantly higher (healthier) lnRMSSD (B = 0.063 ± 0.030 and B = 0.056 ± 0.027, respectively; both p < 0.05). Sensitivity analyses strengthened these associations and yielded further associations of higher lnSDNN and lnRMSSD when replacing 30 min of short-bout MVPA with equivalent amounts of long-bout MVPA (B = 0.074 ± 0.037 and B = 0.091 ± 0.046, respectively).

CONCLUSION

Replacing ST with long-bout MVPA is a potential strategy to improve cardiac-autonomic function in previously pregnant women.

Association of Physical Activity and Sedentary Time with Cardio-Autonomic Regulation in Women

Background: Low moderate-to-vigorous-intensity physical activity (MVPA) and high sedentary time (ST) may contribute to cardiovascular disease (CVD) risk in women, perhaps via cardiac autonomic dysregulation. We examined associations of total, leisure, and occupational MVPA and ST with cardiac autonomic regulation in women. Methods: Data were from 522 women (age = 37.7 ± 5.7 years; 59%white) who participated in the follow-up study of the Pregnancy Outcomes and Community Health Study (between 2011 and 2014). MVPA and ST (hours/day) were self-reported using the Modifiable Activity Questionnaire. Cardiac autonomic regulation was assessed by calculating heart rate variability (HRV) indices (resting heart rate, natural logarithm standard deviation of normal R-R intervals; lnSDNN [total variability], natural logarithm root mean square of the successive differences; lnRMSSD [cardiac parasympathetic activity]) with Kubios software from a 5-minute, seated electrocardiogram. Progressive generalized linear models evaluated associations of total, leisure, and occupational MVPA and ST with HRV indices while adjusting for confounders (demographics, health-related factors), and then potential mediators (clinical variables). A final model evaluated the relationship between ST and HRV stratified by MVPA level. Results: Adjusting for confounders, total and leisure MVPA were associated with favorable lnSDNN (B = 0.027 [p = 0.014] and B = 0.074 [p = 0.009], respectively) and lnRMSSD (B = 0.036 [p = 0.015] and B = 0.075 [p = 0.043], respectively). Adjustment for mediators tended to strengthen the observed significant associations. No associations were found between occupational MVPA or any ST measure with HRV indices (p > 0.05). Neither MVPA nor ST were associated with heart rate. When stratified by MVPA level, leisure ST was associated with unfavorable lnRMSSD (B = -0.041, [p = 0.042]) only among women who did not meet leisure MVPA recommendations. Conclusion: Cardiac autonomic dysregulation may be a mechanism through which low leisure MVPA and, among low-active women, high leisure ST contribute to CVD risk among women.

First Trimester Prediction of Preterm Delivery in the Absence of Other Pregnancy-Related Complications Using Cardiovascular-Disease Associated MicroRNA Biomarkers

The aim of the study was to determine if aberrant expression profile of cardiovascular disease associated microRNAs would be able to predict within 10 to 13 weeks of gestation preterm delivery such as spontaneous preterm birth (PTB) or preterm prelabor rupture of membranes (PPROM) in the absence of other pregnancy-related complications (gestational hypertension, preeclampsia, fetal growth restriction, or small for gestational age). In addition, we assessed if aberrant expression profile of cardiovascular disease associated microRNAs would be able to predict preterm delivery before and after 34 weeks of gestation. The retrospective study was performed within the period November 2012 to March 2020. Whole peripheral blood samples were collected from 6440 Caucasian individuals involving 41 PTB and 65 PPROM singleton pregnancies. A control group, 80 singleton term pregnancies, was selected on the base of equal sample storage time. Gene expression of 29 selected cardiovascular disease associated microRNAs was studied using real-time RT-PCR. Downregulation of miR-16-5p, miR-20b-5p, miR-21-5p, miR-24-3p, miR-26a-5p, miR-92a-3p, miR-126-3p, miR-133a-3p, miR-145-5p, miR-146a-5p, miR-155-5p, miR-210-3p, miR-221-3p and miR-342-3p was observed in pregnancies with preterm delivery before 37 (≤36 + 6/7) weeks of gestation. Majority of downregulated microRNAs (miR-16-5p, miR-24-3p, miR-26a-5p, miR-92a-3p, miR-133a-3p, miR-145-5p, miR-146a-5p, miR-155-5p, miR-210-3p, and miR-342-3p) was associated with preterm delivery occurring before 37 (≤36 + 6/7) weeks of gestation. The only miR-210-3p was downregulated in pregnancies with preterm delivery before 34 (≤33 + 6/7) weeks of gestation. The type of preterm delivery also had impact on microRNA gene expression profile. Downregulation of miR-24-3p, miR-92a-3p, miR-155-5p, and miR-210-3p was a common feature of PTB and PPROM pregnancies. Downregulation of miR-16-5p, miR-20b-5p, miR-26a-5p, miR-126-3p, miR-133a-3p, miR-146a-5p, miR-221-3p, and miR-342-3p appeared just in PTB pregnancies. No microRNA was uniquely dysregulated in PPROM pregnancies. The combination of 12 microRNAs (miR-16-5p, miR-20b-5p, miR-21-5p, miR-24-3p, miR-26a-5p, miR-92a-3p, miR-133a-3p, miR-145-5p, miR-146a-5p, miR-155-5p, miR-210-3p, and miR-342-3p, AUC 0.818, p < 0.001, 74.53% sensitivity, 75.00% specificity, cut off > 0.634) equally as the combination of 6 microRNAs (miR-16-5p, miR-21-5p, miR-24-3p, miR-133a-3p, miR-155-5p, and miR-210-3p, AUC 0.812, p < 0.001, 70.75% sensitivity, 78.75% specificity, cut off > 0.652) can predict preterm delivery before 37 weeks of gestation in early stages of gestation in 52.83% pregnancies at 10.0% FPR. Cardiovascular disease associated microRNAs represent promising biomarkers with very good diagnostical potential to be implemented into the current routine first trimester screening programme to predict preterm delivery.

Cardiometabolic Profiles in Women with a History of Hypertensive and Normotensive Fetal Growth Restriction

Background: The majority of evidence on associations between pregnancy complications and future maternal disease focuses on hypertensive (Ht) complications. We hypothesize that impaired cardiometabolic health after pregnancies complicated by severe fetal growth restriction (FGR) is independent of the co-occurrence of hypertension. Materials and Methods: In a prospective cohort of women with a pregnancy complicated by early FGR (delivery <34 weeks gestation), with or without concomitant hypertension, cardiometabolic risk factors were assessed after delivery. A population-based reference cohort was used for comparison, and analyses were adjusted for age, current body mass index (BMI), smoking habits, and hormonal contraceptive use. Results: Median time from delivery to assessment was 4 months in both the Ht (N = 115) and normotensive (Nt) (N = 42) FGR groups. Compared with the reference group (N = 380), in both FGR groups lipid profile and glucose homeostasis at assessment were unfavorable. Women with Ht-FGR had the least favorable cardiometabolic profile, with higher prevalence ratios (PRs) for diastolic blood pressure >85 mmHg (PR 4.0, 95% confidence interval [CI] 2.1-6.7), fasting glucose levels >5.6 mmol/L (PR 2.9, 95% CI 1.4-5.6), and total cholesterol levels >6.21 mmol/L (PR 4.5, 95% CI 1.9-8.8), compared with the reference group. Women with Nt-FGR more often had a BMI >30 kg/m² (PR 2.5, 95% CI 1.2-4.7) and high-density lipoprotein-cholesterol levels <1.29 mmol/L (PR 2.4, 95% CI 1.4-3.5), compared with the reference group. Conclusions: Women with a history of FGR showed unfavorable short-term cardiometabolic profiles in comparison with a reference group, independent of the co-occurrence of hypertension. Therefore, women with a history of FGR may benefit from cardiovascular risk factor assessment and subsequent risk reduction strategies.

Pregnancy is accompanied by larger high density lipoprotein particles and compositionally distinct subspecies

Pregnancy is accompanied by significant physiological changes, which can impact the health and development of the fetus and mother. Pregnancy-induced changes in plasma lipoproteins are well documented, with modest to no impact observed on the generic measure of high density lipoprotein (HDL) cholesterol. However, the impact of pregnancy on the concentration and composition of HDL subspecies has not been examined in depth. In this prospective study, we collected plasma from 24 nonpregnant and 19 pregnant women in their second trimester. Using nuclear magnetic resonance (NMR), we quantified 11 different lipoprotein subspecies from plasma by size, including three in the HDL class. We observed an increase in the number of larger HDL particles in pregnant women, which were confirmed by tracking phospholipids across lipoproteins using high-resolution gel-filtration chromatography. Using liquid chromatography-mass spectrometry (LC-MS), we identified 87 lipid-associated proteins across size-speciated fractions. We report drastic shifts in multiple protein clusters across different HDL size fractions in pregnant females compared with nonpregnant controls that have major implications on HDL function. These findings significantly elevate our understanding of how changes in lipoprotein metabolism during pregnancy could impact the health of both the fetus and the mother.

A History of Preterm Delivery Is Associated with Aberrant Postpartal MicroRNA Expression Profiles in Mothers with an Absence of Other Pregnancy-Related Complications

This prospective cross-sectional case-control study investigated the postpartal gene expression of microRNAs associated with diabetes/cardiovascular/cerebrovascular diseases in the peripheral white blood cells of women with anamnesis of preterm prelabor rupture of membranes (n = 58), spontaneous preterm birth (n = 55), and term delivery (n = 89) by a quantitative reverse transcription polymerase chain reaction. After pregnancies complicated by preterm prelabor rupture of membranes or spontaneous preterm birth, mothers showed diverse expression profiles for 25 out of 29 tested microRNAs (miR-1-3p, miR-16-5p, miR-17-5p, miR-20a-5p, miR-20b-5p, miR-21-5p, miR-23a-3p, miR-24-3p, miR-26a-5p, miR-29a-3p, miR-100-5p, miR-103a-3p, miR-125b-5p, miR-126-3p, miR-130b-3p, miR-133a-3p, miR-143-3p, miR-145-5p, miR-146a-5p, miR-181a-5p, miR-195-5p, miR-199a-5p, miR-221-3p, miR-499a-5p, and miR-574-3p). The earliest gestational ages at delivery and the lowest birth weights of newborns were associated with the highest postpartal levels of the previously mentioned microRNAs in maternal peripheral white blood cells. Administration of tocolytic drugs in order to prolong pregnancy, used in order to administer and complete a full course of antenatal corticosteroids, was associated with alterations in postpartal microRNA expression profiles to a lesser extent than in women with imminent delivery, where there was insufficient time for administration of tocolytics and antenatal corticosteroids. Overall, mothers who did not receive tocolytic therapy (miR-24-3p and miR-146a-5p) and mothers who did not receive corticosteroid therapy (miR-1-3p, miR-100-5p, and miR-143-3p) had increased or showed a trend toward increased postpartal microRNA expression when compared with mothers given tocolytic and corticosteroid therapy. In addition, mothers with serum C-reactive protein levels above 20 mg/L, who experienced preterm labour, showed a trend toward increased postpartal expression profiles of miR-143-3p and miR-199a-5p when compared with mothers with normal serum C-reactive protein levels. On the other hand, the occurrence of maternal leukocytosis, the presence of intra-amniotic inflammation (higher levels of interleukin 6 in the amniotic fluid), and the administration of antibiotics at the time of preterm delivery had no impact on postpartal microRNA expression profiles in mothers with a history of preterm delivery. Likewise, the condition of the newborns at the moment of birth, determined by Apgar scores at 5 and 10 min and the pH of cord arterial blood, had no influence on the postpartal expression profiles of mothers with a history of preterm delivery. These findings may contribute to explaining the increased cardiovascular risk in mothers with anamnesis of preterm delivery, and the greater increase of maternal cardiovascular risk with the decrease of gestational age at delivery. Women with preterm delivery in their anamnesis represent a high-risk group with special needs on a long-term basis, with a need to apply preventive and therapeutic interventions as early as possible.

The Use of Sex-Specific Factors in the Assessment of Women's Cardiovascular Risk

Cardiovascular disease (CVD) is the leading cause of death among women in the United States. As compared with men, women are less likely to be diagnosed appropriately, receive preventive care, or be treated aggressively for CVD. Sex differences between men and women have allowed for the identification of CVD risk factors and risk markers that are unique to women. The 2018 American Heart Association/American College of Cardiology Multi-Society cholesterol guideline and 2019 American College of Cardiology/American Heart Association guideline on the primary prevention of CVD introduced the concept of risk-enhancing factors that are specific to women and are associated with an increased risk of incident atherosclerotic CVD in women. These factors, if present, would favor more intensified lifestyle interventions and consideration of initiation or intensification of statin therapy for primary prevention to mitigate the increased risk. In this primer, we highlight sex-specific CVD risk factors in women, stress the importance of eliciting a thorough obstetrical and gynecological history during cardiovascular risk assessment, and provide a framework for how to initiate appropriate preventive measures when sex-specific risk factors are present.