Cardiac output and peripheral vascular resistance during normotensive and hypertensive pregnancy - a systematic review and meta-analysis.

BACKGROUND: In-depth insight into haemodynamic changes during normotensive pregnancy may help identify women at risk for gestational hypertensive complications. OBJECTIVES: To determine the magnitude of changes in cardiac output and its determinants stroke volume and heart rate, and total peripheral vascular resistance during singleton normotensive and hypertensive pregnancies. SEARCH STRATEGY: PubMed (NCBI) and Embase (Ovid) databases were searched from their inception up to November 2019. SELECTION CRITERIA: Studies reporting original measurements of haemodynamic parameters during pregnancy together with a non-pregnant reference measurement. Studies including women using antihypertensive medication were excluded. DATA COLLECTION AND ANALYSIS: Pooled mean differences between pregnant and non-pregnant women, and absolute values of haemodynamic parameters were calculated for predefined gestational intervals using a random-effects model in normotensive and hypertensive pregnancy. Meta-regression analysis was used to analyse group differences in adjustments and absolute values during pregnancy. MAIN RESULTS: In normotensive pregnancies, cardiac output increased from the first weeks on, reaching its highest level early in the third trimester (mean difference, 1.41 l·min1 ; 95% CI 1.18-1.63 l·min). In parallel, vascular resistance decreased progressively until its nadir in the early third trimester (mean difference, -331 dyn·sec-1 ·cm-5 ; 95% CI -384 to -277 dyn·sec-1 ·cm-5 ) and then increased slightly at term. In hypertensive pregnancies, the initial cardiac output increase was higher and vascular resistance did not change throughout gestation compared with reference values. CONCLUSIONS: Hemodynamic changes in women who eventually develop hypertensive complications are substantially different. Serial monitoring and plotting against developed normograms can identify women at risk and may allow timely intervention. TWEETABLE ABSTRACT: Monitoring haemodynamic changes in pregnancy helps identify women at risk for hypertensive complications.

Cardiac remodeling and pre-eclampsia: an overview of microRNA expression patterns.

Pre-eclampsia (PE) is strongly associated with heart failure (HF) later in life. During PE pregnancy, the left ventricle undergoes concentric remodeling which often persists after delivery. This aberrant remodeling can induce a molecular signature that can be evaluated in terms of microRNAs (miRNAs) and which may help to explain the associated increased risk of HF. For this review, we performed a literature search of PubMed (National Center for Biotechnology Information), identifying studies on miRNA expression in concentric remodeling and on miRNA expression in PE. The miRNA data were stratified based on origin (isolated from humans or animals and from tissue or the circulation) and both datasets compared in order to generate a list of miRNA expression patterns in concentric remodeling and in PE. The nine miRNAs identified in both concentric remodeling and PE-complicated pregnancy were: miR-1, miR-18, miR-21, miR-29b, miR-30, miR-125b, miR-181b, miR-195 and miR-499-5p. We found five of these miRNAs (miR-18, miR-21, miR-125b, miR-195 and miR-499-5p) to be upregulated in both PE pregnancy and cardiac remodeling and two (miR-1 and miR-30) to be downregulated in both; the remaining two miRNAs (miR-29b and miR-181b) showed upregulation during PE but downregulation in cardiac remodeling. This innovative approach may be a step towards finding relevant biomarkers for complicated pregnancy and elucidating their relationship with remote cardiovascular disease. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Initial and delayed stress phase imaging in a single-injection double-acquisition SPECT. The potential value of early 99mTc-MIBI redistribution in assessment of myocardial perfusion reversibility in patients with coronary artery disease.

UNLABELLED: Some studies reported that 99mTc-MIBI may redistribute in ischaemic myocardium and this phenomenon may have potential role for better assessment of viability by delayed 99mTc-MIBI imaging. Some studies also suggested that infusion of low dose dobutamine during delayed imaging may enhance the value of 99mTc-MIBI imaging for evaluation of viability. The aim of this study is to determine whether the observed changes of perfusion defects on delayed images are caused by early radiotracer redistribution or as a result of reversal partial volume effect secondary to inotropic stimulation. PATIENTS, METHODS: 89 patients with angiographically proven coronary artery disease (CAD) were enrolled in this randomized clinical trial study. In all cases, gated-SPECT images were obtained 60 minutes after stress with dipyridamole injection. Subsequently the patients were randomly allocated in two groups and the second imaging was performed at 120th minute during low dose dobutamine (dobutamine group; 45 cases) or placebo infusion (placebo group; 44 cases). Difference between summed stress score of the first (SSS1) and second (SSS2) stress images (DeltaSSS) was considered as a marker of reversibility in single-injection double-acquisition (SIDA) protocol. Also summed difference score (SDS) was recorded as a marker of reversibility in standard stress/rest, double-injection double-acquisition (DIDA) protocol. DeltaSSS of the two studied groups were compared. Also the correlation and agreement between DeltaSSS and SDS were analyzed. RESULTS: A significant difference was found between SSS1 (median 15, range 0-48) and SSS2 (median 11, range 0-42) in total patients (p < 0.0001). A significant correlation was noted between DeltaSSS and SDS in dobutamine group (r = 0.58, p = 0.002) as well as in placebo group (r = 0.57, p < 0.0001). Considering DIDA protocol as a standard reference method, the influence of dobutamine infusion was not shown to be significantly different from the placebo effect on the magnitude of fixed or reversible perfusion defects in SIDA protocol. CONCLUSION: The changes in the magnitude of the perfusion defects may occur in the first hours of 99mTc-MIBI injection in the stress phase imaging. These changes correlate well and are in agreement with perfusion improvement on the rest images. This phenomenon may be independent of improvement in myocardial function, in more delayed imaging or following inotropic augmentation, and thus is likely due to 99mTc-MIBI redistribution. This may open new technical and clinical aspects and potentials for 99mTc-MIBI imaging.