Measurement Of Pulmonary Artery Pressure Research Articles

Measurement inaccuracy reported via the Manufacturer and User Facility Device Experience database for an implantable pulmonary artery pressure sensor: recalibration direction and magnitude results

Abstract Introduction Remote monitoring using an implantable pulmonary artery pressure (PAP) sensor (CardioMEMS HF system) in patients with heart failure (HF) has been consistently shown to reduce HF hospitalizations [1]. The success of this approach relies on the accurate measurement of diastolic PAP (dPAP) over time to allow early interventions such as diuretic intensification [2]. However, it remains unclear how the measurement accuracy changes over time after the initial calibration at the time of device implantation. Purpose This study aims to identify measurement inaccuracy events and to quantify the magnitude and direction of required device recalibration for CardioMEMS devices as reported in a large-scale regulatory device database. Methods We used the publicly accessible Manufacturer and User Facility Device Experience (MAUDE) data maintained by the US Food and Drug Administration (FDA). The summary search was performed for the CardioMEMS pulmonary artery pressure sensor for the entire product life cycle from January 2009 to February 2024 [3,4]. The entries related to the measurement accuracy under ‘Device Problems’ categories were obtained. Tested accuracy was reported to have been within ±10mmHg of a reference pressure measurement throughout simulated use for 10 years [5]. Normal range for dPAP is ~8mmHg to 15mmHg [6]. Results A total of 2656 entries were obtained. Following categories were identified for the reported entries: device sensing problem (N=999, 38%); incorrect measurement (N=1349, 52%); incorrect measurement, inappropriate waveform (N=279, 11%), and incorrect, inadequate, or imprecise results or readings (N=29, 1%). After excluding 56 entries for missing information, 2600 entries were included for the analysis. A total of 1676 (64%) entries reported the need for recalibration of the CardioMEMS device. A mean PAP difference (defined as the difference of the mean PAP reference value measured at the time of recalibration minus the CardioMEMS reading obtained during the reference measurement) is shown in Figure 1. Compared to the reference pressure values at the time of recalibration, 488 (29%) of CardioMEMS readings were higher and 1188 (71%) were lower. The absolute recalibration pressure difference was 14.5 ± 9.3 mmHg (mean ± standard deviation, range 0.02-59.3 mmHg). The recalibration by more than 10 mmHg was reported in 1040 (40%) entries. Conclusions Suspected measurement inaccuracy with CardioMEMS device is not uncommon and often necessitate recalibration. Almost one-half (40%) of the recalibrations required more than 10 mmHg correction. These results should inform clinicians to consider recalibration along the course of CardioMEMS monitoring if there is discordance between clinical assessment and the values from the device.Figure 1.Figure 2

Association between early pulmonary arterial pressure measurements and bronchopulmonary dysplasia or mortality in very preterm infants: a prospective cohort study

BackgroundPrematurity is a significant risk for bronchopulmonary dysplasia related pulmonary artery pressure.ObjectiveTo determine the association between pulmonary artery pressure in the early days of life and the development of bronchopulmonary...

The Use of Pulmonary Arterial Pressure (PAP) for Improved Beef Cattle Management.

Pulmonary arterial pressure (PAP) determines cattle's susceptibility to High Altitude Disease (HAD), also known as Brisket Disease, High Mountain Disease, and right-sided heart failure (RHF). This non-infectious disease causes pulmonary hypertension due to hypoxia. PAP measures the resistance of blood flow through the lungs. It is estimated that 1.5 million head of cattle are raised in high-altitude environments (above 1500 m), and HAD accounts for 3-5% of calf death loss yearly. In addition, there have been increasing concerns about feedlot cattle succumbing to RHF at moderate elevations. This review focuses on the historical background, explanation of PAP measurement and scores, genetic implications, and the relationship between PAP and economically relevant traits. Specifically, traits such as gestation length, birth weight, weaning weight, and yearling weight may impact PAP scores. In addition, environmental effects and other factors impacting PAP score variations are discussed. Information gaps and research needs are addressed to determine where missing information could improve the understanding of PAP while also benefiting beef cattle producers in high-elevation production systems.

Abstract 1073: Longitudinal Imaging Of NF-kappaB In Murine Pulmonary Embolism

Objective: Pulmonary embolism (PE) is a common condition that urgently needs novel diagnostic and therapeutic strategies. Here, we investigated PE-induced inflammation via longitudinal imaging of transcription factor NF-kappaB (NFkB) activation signals in murine PE. Understanding the temporal activation of inflammatory mediators, such as NFkB, in PE may lead to future medical interventions or better patient stratification. Methods: NFkB activation was assessed using male, 12-16w old, NFkB-GFP-luciferase (NGL) reporter mice (n=20 PE animals). Stasis venous thrombosis (VT) was induced in the femoral veins of donor mice on day 0. On day 1, the thrombus was resected and intravenously injected into recipient mice to create the PE model. PE animals underwent bioluminescence imaging on days -1, 1, 4, and 7. Regions-of-interest (ROI) areas were kept constant and placed over areas of PE as verified in other modalities. Lung and PE morphometrics were imaged by fluorescence-mediated tomography and computed tomography using a fibrin-specific molecular imaging agent, FTP11 (i.v. 150nmol/kg). Cardiac function pre- and post-PE was assessed by ultrasound and pulmonary arterial pressure measurements. Mouse cohorts were sacrificed 1, 4, and 7 days following stasis-VT embolization and underwent histological analysis of the PE. Results: The mean volume of the femoral stasis-VT was 1.21±0.25 mm 3 . The bioluminescence signal plateau was found at 4-8 minutes post-intravenous injection of D-luciferin in PE animals. The six-minute post-injection image was utilized in comparing longitudinal images. Bioluminescence from the activation of NFkB in the PE ROI showed a maximal signal in the day 1 PE with a 55.0% (334 to 151RU) decrease in signal from day 1 to day 7(p<0.05). Histological and protein assays validated the activation and localization of NFkB. In PE animals, immunohistochemistry of infiltrating CD45-positive cells showed increased cell numbers from day 1 to day 7 (p<0.05). Since PE is confided spatially to a lung lobe, contralateral PE-negative lobes also showed increased infiltrating cells compared to sham animals. Conclusions: Quantitative serial imaging pre- and post-PE demonstrates an inflammatory timeline in PE-induced NFkB activation.

"This Patient Needs a Doctor, Not a Guideline!" The Zone of Uncertainty in Pulmonary Arterial Wedge Pressure Measurement.

"This Patient Needs a Doctor, Not a Guideline!" The Zone of Uncertainty in Pulmonary Arterial Wedge Pressure Measurement.

Impact of respiratory cycle during mechanical ventilation on beat-to-beat right ventricle stroke volume estimation by pulmonary artery pulse wave analysis.

The same principle behind pulse wave analysis can be applied on the pulmonary artery (PA) pressure waveform to estimate right ventricle stroke volume (RVSV). However, the PA pressure waveform might be influenced by the direct transmission of the intrathoracic pressure changes throughout the respiratory cycle caused by mechanical ventilation (MV), potentially impacting the reliability of PA pulse wave analysis (PAPWA). We assessed a new method that minimizes the direct effect of the MV on continuous PA pressure measurements and enhances the reliability of PAPWA in tracking beat-to-beat RVSV. Continuous PA pressure and flow were simultaneously measured for 2-3min in 5 pigs using a high-fidelity micro-tip catheter and a transonic flow sensor around the PA trunk, both pre and post an experimental ARDS model. RVSV was estimated by PAPWA indexes such as pulse pressure (SVPP), systolic area (SVSystAUC) and standard deviation (SVSD) beat-to-beat from both corrected and non-corrected PA signals. The reference RVSV was derived from the PA flow signal (SVref). The reliability of PAPWA in tracking RVSV on a beat-to-beat basis was enhanced after accounting for the direct impact of intrathoracic pressure changes induced by MV throughout the respiratory cycle. This was evidenced by an increase in the correlation between SVref and RVSV estimated by PAPWA under healthy conditions: rho between SVref and non-corrected SVSD -0.111 (0.342), corrected SVSD 0.876 (0.130), non-corrected SVSystAUC 0.543 (0.141) and corrected SVSystAUC 0.923 (0.050). Following ARDS, correlations were SVref and non-corrected SVSD -0.033 (0.262), corrected SVSD 0.839 (0.077), non-corrected SVSystAUC 0.483 (0.114) and corrected SVSystAUC 0.928 (0.026). Correction also led to reduced limits of agreement between SVref and SVSD and SVSystAUC in the two evaluated conditions. In our experimental model, we confirmed that correcting for mechanical ventilation induced changes during the respiratory cycle improves the performance of PAPWA for beat-to-beat estimation of RVSV compared to uncorrected measurements. This was demonstrated by a better correlation and agreement between the actual SV and the obtained from PAPWA.

Twelve-month follow-up results from the SIRONA 2 clinical trial.

In the SIRONA 2 trial, the safety and efficacy of pulmonary artery (PA) pressure (PAP)-guided heart failure (HF) management using a novel PAP sensor were assessed at 30 and 90days, respectively, and both endpoints were met. The current study examines the prespecified secondary endpoints of safety and accuracy of the PA sensor along with HF hospitalizations and mortality, HF symptoms, functional capacity, quality of life, and patient compliance through 12months. SIRONA 2 is a prospective, multi-centre, open-label, single-arm trial evaluating the Cordella™ PA Sensor System in 70 patients with New York Heart Association (NYHA) functional class III HF with a prior HF hospitalization and/or increase of N-terminal pro-brain natriuretic peptide within 12months of enrolment. Sensor accuracy was assessed and compared with measurements obtained by standard right heart catheterization (RHC). Safety was defined as freedom from prespecified adverse events associated with use of the Cordella PA Sensor System and was assessed in all patients who entered the cath lab for PA sensor implant. HF hospitalizations and mortality, HF symptoms, functional capacity, quality of life, and patient compliance were also assessed. At 12months, there was good agreement between the Cordella PA Sensor System and RHC, with the average difference for mean PAP being 2.9±7.3mmHg. The device safety profile was excellent with 98.4% freedom from device/system-related complications. There were no pressure sensor failures. HF hospitalizations and mortality were low with a rate of 0.33 event per patient year. Symptoms as assessed by NYHA (P<0.0001) and functional capacity as measured by 6min walk test (P=0.02) were significantly improved. Patients' adherence to daily transmissions of PAP and vital signs measurements was 95%. Long-term follow-up of the SIRONA 2 trial supports the safety and accuracy of the Cordella PA Sensor System in enabling comprehensive HF management in NYHA class III HF patients.

Exploring the impacts of fescue toxicosis on the pulmonary arterial pressure of angus cows.

Vasoconstriction of peripheral blood vessels is one of the hallmark symptoms of fescue toxicosis in cattle. Thus, it was hypothesized that exposure to ergot alkaloids would increase the pulmonary arterial pressure (PAP). The objectives of this study were to examine the relationship between PAP and different physiological parameters of cows grazing either endophyte-infected (EI) or novel-endophyte (EN) fescue, then evaluate changes in PAP and other physiological measurements in cows exposed to EI pastures and deemed as susceptible or tolerant based on animal performance. Pregnant Angus cows at 2 different locations grazed either EI or EN fescue pastures for 14 consecutive weeks starting in early April of 2022. Forage measurements were collected to assess ergot alkaloid exposure throughout the study. In addition to measuring PAP, weekly measurements and blood samples were collected to evaluate physiological responses to ergot alkaloid consumption. The Fescue Toxicosis Selection Method (FTSM) was used for a post hoc analysis to identify cattle as either tolerant (EI-TOL) or susceptible (EI-SUS) when challenged with ergot alkaloid exposure. Data were analyzed using a MIXED procedure of SAS with repeated measures. Cows grazing on EN pastures had greater mean PAP values than EI cows, (P < 0.01), whereas a location effect was identified when comparing both EI-TOL and EI-SUS groups (P < 0.01). Cows exposed to EN pastures had greater average daily gain (ADG) (P = 0.04) and progesterone (P4) concentrations (P < 0.01), and lower hair shedding scores (HSS; P < 0.01) than EI cows. The EI-TOL cows tended to have greater final body weight, ADG and had lower HSS (P < 0.01) than EI-SUS cows. While cattle consuming EI tall fescue exhibited classical physiological changes, the decrease in PAP of cattle consuming EI fescue was unexpected and contradicted the initial hypothesis. Furthermore, the FTSM provides a means to identify animals with superior performance in spite of the chronic exposure to ergot alkaloids. Continued investigations examining the interaction between ergot alkaloid exposure and cardiovascular parameters will lead to a fuller understanding of the disease and are pivotal for developing innovative strategies that enhance best management practices to help guarantee the sustainability of the U.S. beef industry.

The Correlation between Lung Ultrasound and Pathology in Rat Model of Monocrotaline-Induced Pulmonary Hypertension.

Pulmonary hypertension (PH) is a progressive and complex pulmonary vascular disease with poor prognosis. The aim of this study was to provide a new understanding of the lung pathology of disease and a noninvasive method in monitoring the establishment of animal models for basic and clinical studies of PH, indeed to explore clinical application value of lung ultrasound for patients with PH. Totally 32 male SD rats were randomly divided into control group, MCT (monocrotaline) group, PDTC (pyrrolidine dithiocarbamate) group, and NS (normal saline) group. Rats in the MCT group, PDTC group, and NS group received single intraperitoneal injection of MCT, while the control group received the same dose of NS. Then, PDTC group and NS group received PDTC and NS daily for treatment at the end of the model. Each group received lung ultrasound examination and measurement of pulmonary arterial pressure (PAP). Then, the rats were sacrificed to take the lung specimens to being observed. The ultrasound and pathological results were analyzed with a semiquantitative score. With the pulmonary artery pressure increases, the MCT group had a higher pulmonary ultrasound score and pathological score compared with the control group (p < 0.05). After PDTC treatment, the pulmonary ultrasound score and the pathological score decline (p < 0.05). We investigated both lung ultrasound scores, and the pathological scores were positively correlated with mean pulmonary artery pressure (mPAP) (both r > 0.8, p < 0.0001). Moreover, lung ultrasound scores were positively correlated with pathological scores (r > 0.8, p < 0.0001). We elucidated lung ultrasound evaluation providing more evidence for the management of PH in the rat model. Moreover, lung ultrasound provided a noninvasive method in monitoring the establishment of animal models for basic and clinical studies of PH.

The Sugen/Hypoxia Rat Model for Pulmonary Hypertension and Right Heart Failure.

Pulmonary hypertension (PH) is a devastating disease, characterized by complex remodeling of the pulmonary vasculature. PH is classified into five groups based on different etiology, pathology, as well as therapy and prognosis. Animal models are essential for the study of underlying mechanisms, pathophysiology, and preclinical testing of new therapies for PH. The complexity of the disease with different clinical entities dictates the necessity for more than one animal model to resemble PH, as a single model cannot imitate the broad spectrum of human PH.Here we describe a detailed protocol for creating a rat model of PH with right ventricular (RV) failure. Furthermore, we present how to characterize it hemodynamically by invasive measurements of RV and pulmonary arterial (PA) pressures. Animals subjected to this model display severe pulmonary vascular remodeling and RV dysfunction. In this model, rats undergo a single subcutaneous injection of Sugen (SU5416, a vascular endothelial growth factor inhibitor) and are immediately exposed to chronic hypoxia in a hypoxia chamber for 3-6weeks. This Sugen/Hypoxia rat model resembles Group 1 PH.

Endobronchial ultrasound: A novel screening test for pulmonary hypertension prior to major pulmonary surgery

ObjectivesPulmonary hypertension (PH) is an important physiologic variable in the assessment of patients undergoing major thoracic operations but all too often neglected because of the need for right heart catheterization (RHC) due to the inaccuracy of transthoracic echocardiography. Patients with lung cancer often require endobronchial ultrasound (EBUS) as part of the staging of the cancer. We sought to investigate whether EBUS can be used to screen these patients for PH. MethodsPatients undergoing a major thoracic operation requiring EBUS for staging were included prospectively in the study. All patients had also a RHC (gold standard). We aimed to compare the pulmonary artery pressure measurements by EBUS with the RHC values. ResultsA total of 20 patients were enrolled in the study. The prevalence of abnormal pulmonary artery pressure was 65% based on RHC. All patients underwent measurement of the pulmonary vascular acceleration time (PVAT) by EBUS with no adverse events. Linear regression analysis comparing PVAT and RHC showed a correlation (r = −0.059, −0.010 to −0.018, P = .007). A receiver operator characteristic curve (area under the curve = 0.736) was used to find the optimal PVAT threshold (140 milliseconds) to predict PH; this was used to calculate a positive and negative likelihood ratio following a positive diagnosis of 2.154 and 0.538, respectively. ConclusionsEBUS interrogation of pulmonary artery hemodynamic is safe and feasible. EBUS may be used as a screening test for PH in high-risk individuals.

Complications in patients with transfusion dependent thalassemia: A descriptive cross-sectional study.

One of the most common hemoglobinopathies globally related to blood transfusion and iron overload in the body is thalassemia syndrome. Increasing ferritin levels can cause severe damage to the patient's body organs. This study aims to evaluate the complications of iron overload on vital body organs in patients with transfusion-dependent beta-thalassemia. This descriptive cross-sectional study was performed in Iran University of Medical Sciences Hospitals on patients with a beta-thalassemia major with frequent blood transfusions. To evaluate the effect of iron overload on vital body organs, hematologic and blood analysis, echocardiography with measurement of pulmonary artery pressure (PAP) and ejection fraction (EF) tests, bone densitometry, and audiometric tests were performed for all patients. Of the 1010 patients participating in this study, 497 (49%) were males, 513 were (51%) females aged 5-74 years, and the majority of participants (85%) were over 20 years old. This study demonstrated that increasing ferritin levels had no notable correlation with sex, cholesterol, low-density lipoprotein, parathyroid hormone, T4, and aspartate aminotransferase. However, elevating ferritin levels had significant correlations with increasing triglyceride, phosphorus, thyroid stimulating hormone, alkaline phosphatase, alanine transaminase, and PAPlevels, age, hearing disorders, splenectomy, osteoporosis, and decreasing high-density lipoprotein, body mass index, calcium, and EFlevels. Improvement in beta-thalassemia patients' survival and quality of life can be due to multidisciplinary care in a comprehensive unit through regular follow-up and early complication detection.

Elevated systolic pulmonary artery pressure is a substantial predictor of increased mortality after transcatheter aortic valve replacement in males, not in females

BackgroundWhile pulmonary hypertension (PH) in patients with severe aortic valve stenosis (AS) is associated with increased mortality after transcatheter aortic valve replacement (TAVR), there is limited data on gender differences in the effects on long-term survival.ObjectiveThe aim of this retrospective, multicenter study was to investigate the prognostic impact of pre-interventional PH on survival of TAVR patients with respect to gender.Methods303 patients undergoing TAVR underwent echocardiography to detect PH prior to TAVR via measurement of systolic pulmonary artery pressure (sPAP). Different cut-off values were set for the presence of PH. The primary endpoint was all-cause mortality at 1, 3 and 5 years.ResultsKaplan–Meier analysis by gender showed that only males exhibited significant increased mortality at elevated sPAP values during the entire follow-up period of 5 years (sPAP ≥ 40 mmHg: p ≤ 0.001 and sPAP ≥ 50 mmHg: p ≤ 0.001 in 1- to 5-year survival), whereas high sPAP values had no effect on survival in females. In Cox regression analysis based on the selected sPAP thresholds, male gender was an independent risk factor for long-term mortality after TAVR in all time courses.ConclusionMale gender was an isolated risk factor for premature death after TAVR in patients with echocardiographic evidence of PH and severe AS. This could mean that, the indication for TAVR should be discussed more critically in men with severe AS and an elevated sPAP, while in females, PH should not be an exclusion criterion for TAVR.Graphical abstractGraphical abstract of the study (Created with BioRender.com)Image material of CoreValve™ Evolut™ was kindly provided by © Medtronic Inc.

Diagnostic values of serum BNP, PTX3, and VEGF in acute pulmonary embolism complicated by pulmonary artery hypertension and their correlations with severity of pulmonary artery hypertension.

This paper aimed to unveil the diagnostic values of serum brain natriuretic peptide (BNP), pentraxin 3 (PTX3), and vascular endothelial growth factor (VEGF) in acute pulmonary embolism complicated by pulmonary artery hypertension (APE-PAH) and their correlations with severity of PAH. A total of 153 patients with APE were selected for our study and divided into the PAH and Non-PAH groups according to the measurement of pulmonary artery pressure by echocardiography. Serum BNP levels were measured by chemiluminescence immunoassay, and serum PTX3 and VEGF levels were appraised by ELISA. The predictive values of BNP, PTX3, and VEGF for APE-PAH were evaluated by applying the receiver operating characteristic (ROC) curve. Spearman test was implemented to correlate BNP, PTX3, and VEGF with the severity of PAH. Higher serum levels of BNP, PTX3, and VEGF were observed in the PAH group versus the Non-PAH group (p < .05). ROC curve analysis indicated that BNP, PTX3, and VEGF had acceptable diagnostic value for predicting APE-PAH. Higher serum levels of BNP, PTX3, and VEGF were witnessed in the moderate and severe PAH groups in contrast to the mild PAH group (p < .05), and the levels of these parameters were elevated in the severe PAH group versus the moderate PAH group (p < .05). Spearman correlation analysis signified that serum BNP (r = 0.377), PTX3 (r = 0.488), and VEGF (r = 0.575) levels were positively correlated with the severity of PAH in APE-PAH patients. Serum BNP, PTX3, and VEGF levels are significantly elevated in APE-PAH patients. Serum BNP, PTX3, and VEGF levels are of clinical value in the diagnosis of APE-PAH patients, and serum BNP, PTX3, and VEGF levels are positively correlated with the severity of PAH and can be used as predictors of the severity of PAH.

An Implantable Wireless System for Remote Hemodynamic Monitoring of Heart Failure Patients.

This article presents an implantable wireless system for remote hemodynamic monitoring, which enables direct, continuous (24/7), and simultaneous measurement of pulmonary arterial pressure (PAP) and cross-sectional area (CSA) of the artery. The implantable device, which measures 3.2 mm × 2 mm × 10 mm, comprises a piezoresistive pressure sensor, an ASIC implemented in 180-nm CMOS, a piezoelectric ultrasound (US) transducer, and a nitinol anchoring loop. An energy-efficient pressure monitoring system, which employs duty-cycling and spinning excitation technique, achieves 0.44 mmHg resolution in a pressure range from -135 mmHg to +135 mmHg and consumes 1.1 nJ conversion energy. The artery diameter monitoring system utilizes the inductive characteristic of the implant's anchoring loop and achieves 0.24 mm resolution within a diameter range of 20 mm to 30 mm, four times higher than echocardiography lateral resolution. The wireless US power and data platform enables simultaneous power and data transfer employing a single piezoelectric transducer in the implant. The system is characterized with an 8.5 cm tissue phantom and achieves a US link efficiency of 1.8%. The uplink data is transmitted by using an ASK modulation scheme parallel to the power transfer and achieves a modulation index of 26%. The implantable system is tested in an in-vitro experimental setup, which emulates the arterial blood flow, and accurately detects fast pressure peaks for systolic and diastolic pressure changes at both 1.28 MHz and 1.6 MHz US powering frequencies, with corresponding uplink data rates of 40 kbps and 50 kbps.

Accuracy of Transthoracic Echocardiogram as a Screening Method in the Clinical Practice of Pulmonary Hypertension Investigation.

The transthoracic echocardiogram (TTE) plays a screening role in the diagnostic algorithm of pulmonary hypertension (PH). Studies have shown a significant disagreement between TTE measurements of the systolic pulmonary artery pressure (sPAP) and right atrial pressure (RAP) and those obtained by right heart catheterization (RHC). To compare TTE measurements of sPAP and RAP with those obtained by RHC in patients being investigated for PH. Patients referred to a PH reference center with a high or intermediate TTE probability of PH upon admission were submitted to RHC. The agreement between sPAP and RAP from both procedures was assessed through the Bland-Altman test. Differences of up to 10 mmHg for sPAP and 5 mmHg for RAP were considered within the variability of the test. Receiver Operating Characteristic (ROC) curve was constructed to determine the most accurate sPAP and Tricuspid regurgitation maximal velocity (TRV)values associated with the diagnosis of PH by RHC. The adopted level of statistical significance was 5%. Ninety-five patients were included. The Bland-Altman analysis showed a bias of 8.03 mmHg (95% CI:-34.9-50.9) for sPAP and -3.30 mmHg (95% CI:-15.9-9.3) for RAP. AUC for sPAP and TRV measured by TTE for discrimination of probable PH were 0.936 (95% CI: 0.836-1.0) and 0.919 (95% CI: 0.837-1.0), respectively. However, only 33.4% of the echocardiographic estimate of sPAP and 55.1% of RAP were accurate, as compared to the measurements obtained by RHC. TTE has a high discriminatory power as a screening diagnostic method for PH despite presenting disagreements between sPAP and RAP absolute values when compared to RHC measurements.

Classification of pulmonary arterial pressure using photoplethysmography and bi-directional LSTM

Pulmonary hypertension (PH) is an obstructive progressive disease of lung vascular system which is usually associated with congenital heart disease (CHD) and it induces the right ventricle failure, adversely affecting quality of life and survival. Pulmonary arterial pressure (PAP) is a direct indicator of PH. The existing PAP measurement techniques are invasive and inconvenient, which are not suitable for frequent use or long time monitoring. A noninvasive and convenient method for measuring PAP is essential for the early prevention and diagnosis of PH. The aim of this study was to propose and evaluate a deep learning approach for the classification and evaluation of pH from noninvasive photoplethysmography (PPG) signals. A wavelet scattering transform method was used to automatically extract features from PPG signals. Then a Bi-directional long short-term memory network (Bi-LSTM) was developed to learn extracted features and finally output the predicted PAP classification results. Based on the results from 216 patients’ records, a classification accuracy of 98.52% was presented. This indicated that the Bi-LSTM model trained on features extracted from PPG signals has satisfying performance in PAP classification. This method will enable the noninvasive and painless measurement of PAP. With the development of wearable devices to capture PPG signals from fingertips and the emergence of deep learning models, noninvasive and convenient PAP predictions will greatly contribute to the early diagnosis and prevention of cardiovascular diseases.

90 Exposure to Endophyte-Infected Tall Fescue Negatively Impacts Pulmonary Arterial Pressure in Beef Cattle

Abstract Fescue toxicosis negatively impacts cattle productivity. Previous data from our laboratory has demonstrated that cattle within a herd respond differently when grazing tall fescue, thus variation within a breed may provide genetic tolerance to the negative effects on performance. Fescue toxicosis results in major impacts on the cardiovascular system, thus it was hypothesized that exposure to ergot alkaloids negatively impacts pulmonary arterial pressure (PAP). The objective of this study was to examine changes in PAP and other production parameters in cattle consuming endophyte-infected tall fescue. Pregnant Angus cows (2 to 4 years; n = 65) were randomly divided to graze either endophyte-infected (EI) or novel endophyte (EN) pastures for4 consecutive weeks starting in April. Weekly measurements were collected to monitor physiological responses to consuming endophyte-infected tall fescue. In addition, PAP was measured every 4 weeks. Data were analyzed using a MIXED procedure of SAS, and statistical significance was determined at P &amp;lt; 0.05 and a tendency at 0.05 &amp;lt; P &amp;lt; 0.10, and evaluated the effects of treatment, age, week, and its interactions on BW, ADG, BCS, HCS, HSS and PAP. Exposure to EI did not affect BW, ADG, or BCS (P &amp;gt;0.05). Whereas, hair coat scores (1-5 scale) were significantly less for cattle consuming EN pastures (2.15 ± 0.05) compared with consuming EI pastures (2.31 ± 0.05; P &amp;lt; 0.05). Additionally, shedding scores (1-5 scale) were reduced in cattle consuming EN pastures (2.3±0.05) compared with consuming EI pastures (2.5±0.05; P&amp;lt; 0.05). There was a significant difference in PAP measurements in cattle exposed to EN pastures (37.16 ± 0.59 mm Hg) compared with EI pastures (31.31 ± 0.56 mm Hg; P &amp;lt; 0.0001). Additionally, PAP scores tended to deviate over the 14-week study between treatment groups (P = 0.0677). As expected, exposure to EI tall fescue resulted in greater HCS and HSS. However, the decrease in PAP in cattle consuming EI fescue was unexpected. Thus, further investigations are needed to examine the interaction between ergot alkaloid exposure on cardiovascular parameters such as PAP to potentially predict genetic differences in beef cattle to identify animals that would have a lower risk of developing fescue toxicosis.

Impact of exercise on pulmonary artery pressure in patients with heart failure using an ambulatory pulmonary artery pressure monitor

In this multicenter prospective study, we explored the relationship between pulmonary artery pressure (PAP) at rest and in response to a 6-min walk test (6MWT) in ambulatory patients with heart failure (HF) with an implantable PAP sensor (CardioMEMS, Abbott). Between 5/2019 and 2/2021, HF patients with a CardioMEMS sensor were recruited from seven sites. PAP was recorded in the supine and seated position at rest and in the seated position immediately post-exercise. In our cohort of 66 patients, mean age was 70 ± 12 years, 67% male, left ventricular ejection fraction (LVEF) < 50% in 53%, mean 6MWT distance was 277 ± 95 meters. Resting seated PAPs were 31 ± 15 mmHg (systolic), 13 ± 8 mmHg (diastolic), and 20 ± 11 mmHg (mean). The pressures were lower in the seated rather than the supine position. After 6MWT, the pressures increased to PAP systolic 37 ± 19 mmHg (p < 0.0001), diastolic 15 ± 10 mmHg (p = 0.006), and mean 24 ± 13 mmHg (p < 0.0001). Patients with elevated PAP diastolic at rest (>15 mmHg) demonstrated a greater increase in post-exercise PAP. The measurement of PAP with CardioMEMS is feasible immediately post-exercise. Despite being well-managed, patients had severely limited functional capacity. We observed a significant increase in PAP with ambulation which was greater in patients with higher baseline pressures.

Monitoring of mitral- and tricuspid valve interventions with CardioMEMS: Insights beyond imaging.

Mitral- and tricuspid regurgitation are associated with significant morbidity and mortality and are increasingly treated interventionally. CardioMEMS is a transcutaneously implanted pressure sensor placed in the pulmonary artery that allows invasive measurement of pulmonary artery pressure and cardiac output. This proof-of-concept study aimed to observe hemodynamic changes as determined by CardioMEMS after transcatheter atrioventricular valve interventions, assess the additional value of CardioMEMS on top of echocardiography, and investigate a potential effect of CardioMEMS on outcome. Patients treated with transcatheter mitral- or tricuspid valve interventions (mitral: TMVR, tricuspid: TTVR) or bicaval valve implantation (bi-CAVI) were recruited. All patients were followed for 12 months. Thirty-six patients were included (4 with CardioMEMS, 32 controls). Patients with CardioMEMS were monitored prior to intervention and 3-12 months thereafter (one received TMVR, one bi-CAVI, one both TMVR and TTVR, and one isolated TTVR). CardioMEMS group: In both patients with TMVR and in the patient with bi-CAVI, mean pulmonary artery pressures decreased (all p < .001) and cardiac output increased significantly (both TMVR p < .001 and bi-CAVI p=.006) while functional parameters, echocardiography, and NT-proBNP were difficult to interpret, unreliable, or both. Changes after TTVR remained inconclusive. Invasive monitoring using CardioMEMS provides important information after mitral- and tricuspid valve interventions. Such data pave the way for a deeper understanding of the prerequisites for optimal patient selection and management for catheter-based interventions.