EP17.13: CVRI as a quick method to estimate peripheral vascular resistance at 13–16 weeks of gestation in patients at high risk of pre‐eclampsia

To investigate the correlation between non-invasive peripheral vascular resistance (PVR) and cardiovascular resistance index (CVRI) in pregnancies at high risk for preterm pre-eclampsia during 13-16 weeks. From September 2023 to February 2024, this ongoing study recruited high-risk pregnancies identified by the FMF algorithm in the first trimester. Hemodynamic assessments were performed at 13-16 weeks, including UtA estimation (PI and S/D ratio) with a Voluson S8 ultrasound machine, and maternal hemodynamics recording (Peripheral vascular resistance [PVR], mean arterial pressure [MAP], heart rate [HR] and pulse pressure [PP]) by bioreactance, using the non-invasive monitor Starling. CVRI was calculated as MAP/HR. PVR prediction involved a backward stepwise linear regression analysis with current maternal BMI, first trimester PAPP-A, and current UtA PI, S/D ratio, PP, and CVRI. Spearman test determined PVR-CVRI correlation. During the study period, 20 high-risk subjects were recruited. The current BMI was 26.8 [24.2 – 30.4] kg/m2. PVR, MAP, HR and PP in this group were 1,257 dynes/sec/cm-5 [1,127 – 1,500], 96.5 mmHg [89.8 – 106.2], 89 bpm [85 – 102] and 35 mmHg [30 – 44], respectively. The CVRI was 1.09 mmHg/bpm [0.99 – 1.15]. After a multivariate regression analysis, the only predictor for PVR was the CVRI (PVR= 57.2043 + [1132.52 * CVRI]; p = 0.01). The correlation coefficient between PVR and CVRI was 53% (Spearman r2= 0.53; p = 0.017). The CVRI proves to be a reliable predictor of PVR in the high-risk population during the 13 to 16-week gestational period. Validating these findings across various gestational age intervals presents an opportunity for a convenient and cost-effective hemodynamic assessment, facilitating pharmacological management of hypertension during pregnancy.