Desarrollo de un modelo por inteligencia artificial con hemodinamia no invasiva para predecir preeclampsia en embarazos de alto riesgo / Artificial Intelligence Modeling with Non-Invasive Hemodynamics to Predict Preeclampsia in High-Risk Pregnancy

RESUMEN Introducción: la preeclampsia (PE) es la principal causa de morbimortalidad materno-fetal en nuestro país. Alteraciones hemodinámicas precoces durante el embarazo podrían predecir la evolución a PE. El machine learning (ML) permite el hallazgo de patrones ocultos que podrían detectar precozmente el desarrollo de PE. Objetivos: desarrollar un árbol de clasificación con variables de hemodinamia no invasiva para predecir precozmente desarrollo de PE. Material y métodos: estudio observacional prospectivo con embarazadas de alto riesgo (n=1155) derivadas del servicio de Obstetricia desde enero 2016 a octubre 2022 para el muestreo de entrenamiento por ML con árbol de clasificación j48. Se seleccionaron 112 embarazadas entre semanas 10 a 16, sin tratamiento farmacológico y que completaron el seguimiento con el término de su embarazo con evento final combinado (PE): preeclampsia, eclampsia y síndrome HELLP. Se evaluaron simultáneamente con cardiografía de impedancia y velocidad de onda del pulso y con monitoreo ambulatorio de presión arterial de 24 hs (MAPA). Resultados: presentaron PE 17 pacientes (15,18%). Se generó un árbol de clasificación predictivo con las siguientes variables: índice de complacencia arterial (ICA), índice cardíaco (IC), índice de trabajo sistólico (ITS), cociente de tiempos eyectivos (CTE), índice de Heather (IH). Se clasificaron correctamente el 93,75%; coeficiente Kappa 0,70, valor predictivo positivo (VPP) 0,94 y negativo (VPN) 0,35. Precisión 0,94, área bajo la curva ROC 0,93. Conclusión: las variables ICA, IC, ITS, CTE e IH predijeron en nuestra muestra el desarrollo de PE con excelente discriminación y precisión, de forma precoz, no invasiva, segura y con bajo costo.

ABSTRACT Background: Preeclampsia (PE) is the main cause of maternal-fetal morbidity and mortality in our country. Early hemodynamic changes during pregnancy could predict progression to PE. Machine learning (ML) enables the discovery of hidden patterns that could early detect PE development. Objectives: The aim of this study was to build a classification tree with non-invasive hemodynamic variables for the early prediction of PE occurrence. Results: Seventeen patients (15.18%) presented PE. A predictive classification tree was generated with arterial compliance index (ACI), cardiac index (CI), cardiac work index (CWI), ejective time ratio (ETR), and Heather index (HI). A total of 93.75% patients were correctly classified (Kappa 0.70, positive predictive value 0.94 and negative predictive value 0.35; accuracy 0.94, and area under the ROC curve 0.93). Conclusion: ACI, CI, CWI, ETR and HI variables predicted the early development of PE in our sample with excellent discrimination and accuracy, non-invasively, safely and at low cost.

Arterial Stiffness: Its Relation with Prediabetes and Metabolic Syndrome and Possible Pathogenesis.

AIMS: To evaluate arterial stiffness indicators in people with prediabetes (PreD) and its possible pathogenesis. MATERIALS AND METHODS: Pulse wave velocity (PWV) was measured in 208 people with FINDRISC ≥ 13 (57 ± 8 years old, 68.7% women) and thereafter divided into those having either normal glucose tolerance (NGT) or PreD. In each subgroup we also identified those with/out insulin resistance (IR) measured by the triglyceride/HDL-c ratio (normal cut off values previously established in our population). Clinical and metabolic data were collected for all participants. PWV was compared between subgroups using independent t test. RESULTS: Women and men had comparable clinical and metabolic characteristics with obesity (BMI ≥ 30) and antihypertensive-statin treatment, almost half with either NGT or PreD. Whereas 48% of NGT people presented IR (abnormally high TG/HDL-c ratio), 52% had PreD. PWV was significantly higher only in those with a complete picture of metabolic syndrome (MS). CONCLUSIONS: Since PWV was significantly impaired in people with a complete picture of MS, clinicians must carefully search for early diagnosis of this condition and prescribe a healthy life-style to prevent development/progression of CVD. This proactive attitude would provide a cost-effective preventive strategy to avoid CVD's negative impact on patients' quality of life and on health systems due to their higher care costs.

Evaluation of ventricular-arterial coupling by impedance cardiography in healthy volunteers.

BACKGROUND: The interplay between cardiac function and the arterial system is currently defined as ventricular-arterial coupling (VAC) and it is an expression of global cardiovascular efficiency. VAC involves a variety of complex interactions between the heart and the vasculature. A basic index of VAC is the ratio of effective arterial elastance (Ea)/ end-systolic elastance (Ees). While this is often done with echocardiography, obtaining Ea/Ees using impedance cardiography is feasible, although this possibility has not been explored so far. OBJECTIVE: The aim of this study was to compare the Ea/Ees values obtained using echocardiography and impedance cardiography. APPROACH: Two independent operators estimated Ea/Ees in 91 (41 ± 14 years old, women 51%) untreated apparently healthy individuals using (1) Doppler echocardiography with the single-beat method developed by Chen et al (2001 J. Am. Coll. Cardiol. 38 2028-34); and (2) data provided by impedance cardiography. The differences between Ea/Ees values were compared and correlation between both methods was estimated. MAIN RESULTS: Although Ea and Ees values calculated by impedance cardiography were lower than those estimated by echocardiography (-0.201 ± 0.457 mmHg ml-1 and -0.193 ± 0.413 mmHg ml-1), Ea/Ees ratio values were similar. Thus, there was no significant difference between the mean values of Ea/Ees estimated by impedance cardiography or echocardiography (Ea/Ees impedance cardiography - Ea/Ees echocardiography = -0.015 ± 0.096, p  = 0.150). Ea/Ees values calculated by both methods were highly correlated (r = 0.85, p  < 0.001), as well as the pre-ejection and left ventricular ejection time (r = 0.83 and r = 0.91, respectively). SIGNIFICANCE: In healthy individuals, estimation of Ea/Ees by impedance cardiography yielded similar values to those obtained using echocardiography.

Office blood pressure values and the necessity of out-of-office measurements in high-risk pregnancies.

OBJECTIVES: To determine if there is an office blood pressure (BP) value below which out-of-office measurements are unnecessary in high-risk pregnant women. METHODS: We conducted a prospective cohort study in women in the second half of high-risk pregnancies. Office BP measurements and ambulatory blood pressure monitoring (ABPM) was performed. The cohort was divided according to quartiles of office BP and in normotension, white-coat hypertension, masked hypertension and sustained hypertension. The risks for preeclampsia/eclampsia for each category were estimated. RESULTS: Three hundred seventy-three women (30 ±â€Š7 years with 32 ±â€Š4 weeks of gestation) were included; 69 women (18.5%) developed preeclampsia/eclampsia. Risk for preeclampsia/eclampsia increased in a stepwise manner through quartiles of systolic office BP (8.8, 13.4, 19.6 and 32.3%, P < 0.001) and diastolic office BP (6.5, 13.7, 19.6 and 34,4%, P < 0.001). OR increased significantly through quartiles of systolic (P = 0.004) and diastolic (P < 0.001) office BP; the significance becomes evident between the second and third quartile, the cut-off point between these was 125/76 mmHg. Prevalence of white-coat and masked hypertension were 3.8 and 24.7%, respectively. Using ABPM, 14/61 office hypertensive women were reclassified as white-coat hypertension but 92/312 normotensive women as masked hypertension. OR for preeclampsia/eclampsia increased significantly in women with masked hypertension. Absolute risk for preeclampsia/eclampsia in women with office BP less than 125/75 mmHg was similar than that in women with normal ABPM, 7.2 and 7.1%, respectively. CONCLUSION: Masked hypertension was a prevalent and high-risk condition. Office BP at least 125/75 mmHg in the second half of gestation seems appropriate to indicate out-of-office measurements in high-risk pregnancies.

Nocturnal hypertension in high-risk mid-pregnancies predict the development of preeclampsia/eclampsia.

OBJECTIVE: The aim of this study was to test if hypertension detected by ambulatory blood pressure monitoring (ABPM) performed at mid-pregnancy, is a useful predictor for preeclampsia/eclampsia (PEEC). METHODS: The study was performed in women coursing high-risk mid-pregnancies. Office blood pressure (BP) was estimated as the mean of three values, taken by a specialized nurse after a 15-min interview, and office hypertension defined as at least 140/90 mmHg. Immediately after, an ABPM was started. Diurnal hypertension was defined as ABPM at least 135/85 mmHg during daily activities, nocturnal hypertension as ABPM at least 120/70 mmHg during night rest. The adjusted risk of PEEC was estimated using logistic regression. RESULTS: Eighty-seven women (mean age 31 ±â€Š7 years) with 23 ±â€Š2 weeks of pregnancy were included. The prevalence of office and ABPM hypertension was 13.8 and 40.2%, respectively. The concordance between both hypertension diagnosis was low (κ = 0.170, P = 0.044). Nocturnal hypertension (35.6%) was more frequent than diurnal hypertension (26.4%). Nocturnal hypertension markedly increased the relative risk of PEEC (OR 5.32, 95% CI 1.48-19.10). The risk of PEEC attributed to diurnal hypertension did not reach statistical significance; and when both, diurnal and nocturnal hypertension were included in the same model, only the second one was a significant predictor (P = 0.012). The relative risk associated with nocturnal hypertension increased for women not taking acetylsalicylic acid (ASA); (OR 11.40, 95% CI 2.35-55.25). CONCLUSION: Nocturnal hypertension at high-risk mid-pregnancy is a frequent condition and a strong predictor for PEEC; the risk doubled for women not taking ASA.