Pulmonary embolism during pregnancy: a 17-year single-center retrospective MDCT pulmonary angiography study

Prevalence and Clinical Features of Pulmonary Embolism in Pregnancy and Puerperium in the Post-COVID-19 Era

OBJECTIVE

Interest in pulmonary embolism (PE) has undergone a renaissance since the emergence of COVID-19 pandemic, but PE researches among pregnant mothers in this post-COVID-19 era remains scarce. This study was conducted to (a) determine PE prevalence rate among pregnant and post-partum women with suspected PE after the COVID 19 pandemic, (b) compare the clinical characteristics, laboratory findings and CT features between the PE and non-PE cohorts, and (c) validate the Pregnancy-Adapted Geneva (PAG) score in our population.

METHODS

This retrospective cross-sectional study involved the review of all maternal cases with suspected PE who underwent diagnostic CTPA in year 2022.

RESULTS

A total of 120 patients represented by 90 pregnant patients and 30 post-partum patients were included in the analysis. The prevalence rate of PE was 22.5% (27/120) and gestational diabetes mellitus prevalence rate was significantly higher (48.1% vs. 26.9%; p = 0.037) in PE cohort. Besides, the proportion of patients with moderately and extremely raised peak D-dimer levels were significantly higher among the PE cohort. In patients with PE, the position of the most proximal clot was identified as subsegmental (n = 6, 22.2%) and segmental (n = 21; 77.8%). The predicted PE risk based on PAG score demonstrated poor calibration with the observed PE risk across all three groups, namely low-risk group (2.3% vs. 15.4%), intermediate-risk group (11.6% vs. 26.3%) and high-risk groups (61.5% vs. 0.0%).

CONCLUSION

Overall, PE among pregnant and post-partum populations remain a convoluted disease without distinctive clinical features. There is a need for a prospectively validated PE risk scores to guide its clinical diagnostic pathway.

A review of the use of CT pulmonary angiography in pregnant and postpartum women at an academic centre

Background

Pulmonary embolism (PE) is a common cause of maternal death during pregnancy and the puerperium yet data on its prevalence in middle-income countries is lacking.

Methods

We examined the medical records and CTPA (computed tomography pulmonary angiography) images of 67 women in an obstetric high care unit during pregnancy and the puerperium. We aimed to determine the prevalence of PE in a high-risk obstetric population undergoing CTPA, assess associated clinical features in this cohort, and determine the prevalence of alternative CT findings.

Results

CTPA detected PE in 11 women (16.42%) and alternative CT findings in 46 (68.6%). Women with PE had a lower systolic blood pressure than those without PE (P = 0.001). Multiple gestation, preterm rupture of membranes, and gestational diabetes were linked to higher PE prevalence.

Conclusions

This study, set in an upper middle-income country, demonstrated a higher CTPA yield for PE and alternative diagnoses than in international literature, emphasising context-specific assessments.

Validating the safety of low-dose CTPA in pregnancy: results from the OPTICA (Optimised CT Pulmonary Angiography in Pregnancy) Study

BACKGROUND

Pulmonary embolism (PE) is a leading cause of pregnancy-related mortality. CT pulmonary angiogram (CTPA) is the first-line advanced imaging modality for suspected PE in pregnancy at institutes offering low-dose techniques; however, a protocol balancing safety with low dose remains undefined. The wide range of CTPA doses reported in pregnancy suggests a lack of confidence in implementing low-dose techniques in this group.

PURPOSE

To define and validate the safety, radiation dose and image quality of a low-dose CTPA protocol optimised for pregnancy.

MATERIALS AND METHODS

The OPTICA study is a prospective observational study. Pregnant study participants with suspected PE underwent the same CTPA protocol between May 2018 and February 2022. The primary outcome, CTPA safety, was judged by the reference standard; the 3-month incidence of venous thromboembolism (VTE) in study participants with a negative index CTPA. Secondary outcomes defined radiation dose and image quality. Absorbed breast, maternal effective and fetal doses were estimated by Monte-Carlo simulation on gestation-matched phantoms. Image quality was assessed by signal-to-noise and contrast-to-noise ratios and a Likert score for pulmonary arterial enhancement.

RESULTS

A total of 116 CTPAs were performed in 113 pregnant women of which 16 CTPAs were excluded. PE was diagnosed on 1 CTPA and out-ruled in 99. The incidence of recurrent symptomatic VTE was 0.0% (one-sided 95% CI, 2.66%) at follow-up. The mean absorbed breast dose was 2.9 ± 2.1mGy, uterine/fetal dose was 0.1 ± 0.2mGy and maternal effective dose was 1.4 ± 0.9mSv. Signal-to-noise ratio (SNR) was 11.9 ± 3.7. Contrast-to-noise ratio (CNR) was 10.4 ± 3.5.

CONCLUSION

The OPTICA CTPA protocol safely excluded PE in pregnant women across all trimesters, with low fetal and maternal radiation.

CLINICAL RELEVANCE

OPTICA (Optimised CT Pulmonary Angiography in Pregnancy) is the first prospective study to define the achievable radiation dose, image-quality and safety of a low-dose CT pulmonary angiogram protocol optimised for pregnancy (NCT04179487). It provides the current benchmark for safe and achievable CT pulmonary angiogram doses in the pregnant population.

KEY POINTS

• Despite the increased use of CT pulmonary angiogram in pregnancy, an optimised low-dose protocol has not been defined and reported doses in pregnancy continue to vary widely. • The OPTICA (Optimised CT Pulmonary Angiography in Pregnancy) study prospectively defines the achievable dose, image quality and safety of a low-dose CT pulmonary angiogram protocol using widely available technology. • OPTICA provides a benchmark for safe and achievable CT pulmonary angiogram doses in the pregnant population.

Peripartum Cardiogenic Shock and Mechanical Circulatory Support

Despite remarkable improvements in the past two decades, the annual cardiovascular mortality rate has remained higher for women than for men. Pregnant women represent an underinvestigated population in clinical research, and the mechanisms of long-term cardiovascular complications in women with obstetric complications remain to be elucidated. Regarding advanced heart failure during pregnancy, interventional approaches are effective but still underutilised. Percutaneous mechanical circulatory support is a valuable option for peripartum cardiogenic shock, although its use during pregnancy is still limited. Survival rates have improved in recent years, but further emphasis on the importance of early recognition and initiation of heart failure treatment in this patient group is warranted. The aims of this review are to summarise the current literature on the implementation of mechanical circulatory support in cardiogenic shock during pregnancy and delivery and to understand the role of percutaneous ventricular assist devices in the management of such conditions.

Breast Shielding Combined With an Optimized Computed Tomography Pulmonary Angiography Pregnancy Protocol: A Special Use-Case for Shielding?

OBJECTIVES

To determine the impact of breast shields on breast dose and image quality when combined with a low-dose computed tomography pulmonary angiography (CTPA) protocol for pregnancy.

METHODS

A low-dose CTPA protocol, with and without breast shields, was evaluated by anthropomorphic phantom and 20 prospectively recruited pregnant participants from January to October 2019. Thermoluminescent dosimeters measured surface and absorbed breast dose in the phantom and surface breast dose in participants. The Monte-Carlo method estimated the absorbed breast dose in participants. Image quality was assessed quantitatively by regions of interest analysis and subjectively by the Likert scale. Doses and image quality for CTPA alone were compared with CTPA with breast shields.

RESULTS

Mean surface and absorbed breast dose for CTPA alone were 1.3±0.4 and 2.8±1.5 mGy in participants, and 1.5±0.7 and 1.6±0.6 mGy in the phantom. Shielding reduced surface breast dose to 0.5±0.3 and 0.7±0.2 mGy in the phantom (66%) and study participants (48%), respectively. Absorbed breast dose reduced to 0.9±0.5 mGy (46%) in the phantom.Noise increased with breast shields at lower kV settings (80 to 100 kV) in the phantom; however, in study participants there was no significant difference between shield and no-shield groups for main pulmonary artery noise (no-shield: 34±9.8, shield: 36.3±7.2, P =0.56), SNR (no-shield: 11.2±3.7, shield: 10.8±2.6, P =0.74) or contrast-to-noise ratio (no-shield: 10.0±3.3, shield: 9.3±2.4, P =0.6). Median subjective image quality scores were comparable (no-shield: 4.0, interquartile range: 3.5 to 4.4, shield: 4.3, interquartile range: 4.0 to 4.5).

CONCLUSION

Combining low-dose CTPA with breast shields confers additional breast-dose savings without impacting image quality and yields breast doses approaching those of low-dose scintigraphy, suggesting breast shields play a role in protocol optimization for select groups.

Determining the diagnostic value of three clinical criteria Wells', YEARS and modified Geneva in pregnant women with suspected pulmonary thromboembolism

BACKGROUND

Diagnosis of pulmonary thromboembolism (PTE) during pregnancy is a challenging medical issue due to complications of X-ray-based imaging studies such as Ct-angiography for neonates and pregnant women. Here we aimed to assess the predictive values of three clinical criteria for diagnosing PTE during pregnancy.

METHODS

This is a retrospective cohort study performed in 2018-2020 on 166 pregnant women suspected of PTE. We reviewed the documents of all patients referred to our medical center with suspected symptoms of PTE. The demographic characteristics of the patients, signs and clinical findings upon the arrival of patients as well as their laboratory tests including D-dimer with a history of abortion or delivery and leg symptoms were entered into the data collection form. Then, according to the information extracted from the patient's files, each patient was evaluated by all clinical PTE criteria, including Wells, YEARS and modified Geneva. For each patient according to clinical criteria and all three algorithms, clinical suspicion for PTE and treatment or non-treatment was determined were compared to the final MDCT result of patients.

RESULTS

The Well's criteria had 100% sensitivity, 6.47% specificity, a positive predictive value of 7.8% and a negative predictive value of 100%. In patients with Well's score of more than four, the sensitivity and specificity of PTE diagnosis were 100% and 6% respectively. The modified Geneva criteria had 100% sensitivity, 8.89% specificity, a positive predictive value of 8.21% and a negative predictive value of 100%. The modified Geneva criteria had 100% sensitivity, 7.74% specificity, positive predictive value of 8.44% and a negative predictive value of 100%.

CONCLUSION

Wells, YEARS and modified Geneva criteria could significantly rule out PTE in pregnancy with 100% sensitivity.

Diagnosing pulmonary thromboembolism: Concerns and controversies

Pulmonary thromboembolism (PTE) is an important cause of mortality/morbidity even today despite advancement in clinical understanding as well as diagnostic facilities. Clinical diagnosis of PTE is often challenging because of nonspecific sign/symptoms. Adherence to clinical decision-making protocols and appropriate use of diagnostic modalities like computed tomography pulmonary angiography can resolve the diagnostic dilemma in most cases and help in the overall management of PTE. This article deals with various concerns as well as controversies surrounding accurate diagnosis of PTE as on date.

Pregnancy-related acute myocardial infarction: a review of the recent literature

Pregnancy-related acute myocardial infarction is a rare and potentially life-threatening cardiovascular event, the incidence of which is growing due to the heightened prevalence of several risk factors, including increased maternal age. Its main aetiology is spontaneous coronary artery dissection, which particularly occurs in pregnancy and may engender severe clinical scenarios. Therefore, despite frequently atypical and deceptive presentations, early recognition of such a dangerous complication of gestation is paramount. Notwithstanding diagnostic and therapeutic improvements, pregnancy-related acute myocardial infarction often carries unfavourable outcomes, as emergent management is difficult owing to significant limitations in the use of ionising radiation-e.g. during coronary angiography, potentially harmful to the foetus even at low doses. Notably, however, maternal mortality has steadily decreased in recent decades, indicating enhanced awareness and major medical advances in this field. In our paper, we review the recent literature on pregnancy-related acute myocardial infarction and highlight the key points in its management.

Can pregnancy-adapted algorithms avoid diagnostic imaging for pulmonary embolism?

The low prevalence of pulmonary embolism (PE) among pregnant patients presenting with suspected PE implies that most of these patients will be found not have the disease. Given this low prevalence, excluding PE in this population has necessitated the use of sensitive and specific diagnostic imaging, such as computed tomography pulmonary angiography or ventilation-perfusion scanning. Recent studies suggest that a clinical prediction rule with D-dimer testing can also be used to exclude a subset of pregnant patients with suspected PE without the need for diagnostic imaging. The YEARS criteria, which consist of clinical signs and symptoms of deep venous thrombosis, hemoptysis, and PE as the most likely diagnosis (a subjective variable), combined with selective D-dimer levels, seem to safely exclude up to one-third of these patients without imaging. The revised Geneva rule using objective variables, combined with nonpregnancy cutoffs for D-dimer levels, offers some promise, although fewer patients avoided imaging (14%). These recent studies provide evidence in support of radiation avoidance for some patients; however, for most, imaging remains the only option. Future studies should focus on improving the safety and techniques of imaging modalities, in addition to improving the specificity of D-dimer testing and objective prediction rules. Studies assessing patients' and physicians' values, preferences, and risk perceptions are also required to assist clinicians in shared decision making when counseling pregnant patients with suspected PE.

Pregnancy and cardiovascular disease

Cardiovascular disease complicates 1-4% of pregnancies - with a higher prevalence when including hypertensive disorders - and is the leading cause of maternal death. In women with known cardiovascular pathology, such as congenital heart disease, timely counselling is possible and the outcome is fairly good. By contrast, maternal mortality is high in women with acquired heart disease that presents during pregnancy (such as acute coronary syndrome or aortic dissection). Worryingly, the prevalence of acquired cardiovascular disease during pregnancy is rising as older maternal age, obesity, diabetes mellitus and hypertension become more common in the pregnant population. Management of cardiovascular disease in pregnancy is challenging owing to the unique maternal physiology, characterized by profound changes to multiple organ systems. The presence of the fetus compounds the situation because both the cardiometabolic disease and its management might adversely affect the fetus. Equally, avoiding essential treatment because of potential fetal harm risks a poor outcome for both mother and child. In this Review, we examine how the physiological adaptations during pregnancy can provoke cardiometabolic complications or exacerbate existing cardiometabolic disease and, conversely, how cardiometabolic disease can compromise the adaptations to pregnancy and their intended purpose: the development and growth of the fetus.