Pulmonary CT perfusion robustly measures cardiac output in the context of multilevel pulmonary occlusion: a porcine study.

BACKGROUND: To validate pulmonary computed tomography (CT) perfusion in a porcine model by invasive monitoring of cardiac output (CO) using thermodilution method. METHODS: Animals were studied at a single center, using a Swan-Ganz catheter for invasive CO monitoring as a reference. Fifteen pigs were included. Contrast-enhanced CT perfusion of the descending aorta and right and left pulmonary artery was performed. For variation purposes, a balloon catheter was inserted to block the contralateral pulmonary vascular bed; additionally, two increased CO settings were created by intravenous administration of catecholamines. Finally, stepwise capillary occlusion was performed by intrapulmonary arterial injection of 75-µm microspheres in four stages. A semiautomatic selection of AFs and a recirculation-aware tracer-kinetics model to extract the first-pass of AFs, estimating blood flow with the Stewart-Hamilton method, was implemented. Linear mixed models (LMM) were developed to calibrate blood flow calculations accounting with individual- and cohort-level effects. RESULTS: Nine of 15 pigs had complete datasets. Strong correlations were observed between calibrated pulmonary (0.73, 95% confidence interval [CI] 0.6-0.82) and aortic blood flow measurements (0.82, 95% CI, 0.73-0.88) and the reference as well as agreements (± 2.24 L/min and ± 1.86 L/min, respectively) comparable to the state of the art, on a relatively wide range of right ventricle-CO measurements. CONCLUSIONS: CT perfusion validly measures CO using LMMs at both individual and cohort levels, as demonstrated by referencing the invasive CO. RELEVANCE STATEMENT: Possible clinical applications of CT perfusion for measuring CO could be in acute pulmonary thromboembolism or to assess right ventricular function to show impairment or mismatch to the left ventricle. KEY POINTS: • CT perfusion measures flow in vessels. • CT perfusion measures cumulative cardiac output in the aorta and pulmonary vessels. • CT perfusion validly measures CO using LMMs at both individual and cohort levels, as demonstrated by using the invasive CO as a reference standard.

Estimation of Right Atrial Pressure by Ultrasound-Assessed Jugular Vein Distensibility in Patients With Heart Failure.

BACKGROUND: Clinical evaluation of central venous pressure is difficult, depends on experience, and is often inaccurate in patients with chronic advanced heart failure. We assessed the ultrasound-assessed internal jugular vein (JV) distensibility by ultrasound as a noninvasive tool to identify patients with normal right atrial pressure (RAP ≤7 mm Hg) in this population. METHODS: We measured JV distensibility as the Valsalva-to-rest ratio of the vein diameter in a calibration cohort (N=100) and a validation cohort (N=101) of consecutive patients with chronic heart failure with reduced ejection fraction who underwent pulmonary artery catheterization for advanced heart failure therapies workup. RESULTS: A JV distensibility threshold of 1.6 was identified as the most accurate to discriminate between patients with RAP ≤7 versus >7 mm Hg (area under the receiver operating characteristic curve, 0.74 [95% CI, 0.64-0.84]) and confirmed in the validation cohort (receiver operating characteristic, 0.82 [95% CI, 0.73-0.92]). A JV distensibility ratio >1.6 had predictive positive values of 0.86 and 0.94, respectively, to identify patients with RAP ≤7 mm Hg in the calibration and validation cohorts. Compared with patients from the calibration cohort with a high JV distensibility ratio (>1.6; n=42; median RAP, 4 mm Hg; pulmonary capillary wedge pressure, 11 mm Hg), those with a low JV distensibility ratio (≤1.6; n=58; median RAP, 8 mm Hg; pulmonary capillary wedge pressure, 22 mm Hg; P<0.0001 for both) were more likely to die or undergo a left ventricular assist device implant or heart transplantation (event rate at 2 years: 42.7% versus 18.2%; log-rank P=0.034). CONCLUSIONS: Ultrasound-assessed JV distensibility identifies patients with chronic advanced heart failure with normal RAP and better outcomes. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03874312.

Agreement between cardiac output estimation with a wireless, wearable pulse decomposition analysis device and continuous thermodilution in post cardiac surgery intensive care unit patients.

PURPOSE: Pulse Decomposition Analysis (PDA) uses integration of the systolic area of a distally transmitted aortic pulse as well as arterial stiffness estimates to compute cardiac output. We sought to assess agreement of cardiac output (CO) estimation between continuous pulmonary artery catheter (PAC) guided thermodilution (CO-CCO) and a wireless, wearable noninvasive device, (Vitalstream, Caretaker Medical, Charlottesville, VA), that utilizes the Pulse Decomposition Analysis (CO-PDA) method in postoperative cardiac surgery patients in the intensive care unit. METHODS: CO-CCO measurements were compared with post processed CO-PDA measurements in prospectively enrolled adult cardiac surgical intensive care unit patients. Uncalibrated CO-PDA values were compared for accuracy with CO-CCO via a Bland-Altman analysis considering repeated measurements and a concordance analysis with a 10% exclusion zone. RESULTS: 259.7 h of monitoring data from 41 patients matching 15,583 data points were analyzed. Mean CO-CCO was 5.55 L/min, while mean values for the CO-PDA were 5.73 L/min (mean of differences +- SD 0.79 ± 1.11 L/min; limits of agreement - 1.43 to 3.01 L/min), with a percentage error of 37.5%. CO-CCO correlation with CO-PDA was moderate (0.54) and concordance was 0.83. CONCLUSION: Compared with the CO-CCO Swan-Ganz, cardiac output measurements obtained using the CO-PDA were not interchangeable when using a 30% threshold. These preliminary results were within the 45% limits for minimally invasive devices, and pending further robust trials, the CO-PDA offers a noninvasive, wireless solution to complement and extend hemodynamic monitoring within and outside the ICU.

Toward Autonomous Pulmonary Artery Catheterization: A Learning-based Robotic Navigation System.

Providing imaging during interventional treatments of cardiovascular diseases is challenging. Magnetic Resonance Imaging (MRI) has gained popularity as it is radiation-free and returns high resolution of soft tissue. However, the clinician has limited access to the patient, e.g., to their femoral artery, within the MRI scanner to accurately guide and manipulate an MR-compatible catheter. At the same time, communication will need to be maintained with a clinician, located in a separate control room, to provide the most appropriate image to the screen inside the MRI room. Hence, there is scope to explore the feasibility of how autonomous catheterization robots could support the steering of catheters along trajectories inside complex vessel anatomies.In this paper, we present a Learning from Demonstration based Gaussian Mixture Model for a robot trajectory optimisation during pulmonary artery catheterization. The optimisation algorithm is integrated into a 2 Degree-of-Freedom MR-compatible interventional robot allowing for continuous and simultaneous translation and rotation. Our methodology achieves autonomous navigation of the catheter tip from the inferior vena cava, through the right atrium and the right ventricle into the pulmonary artery where an interventions is performed. Our results show that our MR-compatible robot can follow an advancement trajectory generated by our Learning from Demonstration algorithm. Looking at the overall duration of the intervention, it can be concluded that procedures performed by the robot (teleoperated or autonomously) required significantly less time compared to manual hand-held procedures.

Characteristics of pulmonary artery catheter use in multicenter ICUs in Japan and the association with mortality: a multicenter cohort study using the Japanese Intensive care PAtient Database.

BACKGROUND: It has been 50 years since the pulmonary artery catheter was introduced, but the actual use of pulmonary artery catheters in recent years is unknown. Some randomized controlled trials have reported no causality with mortality, but some observational studies have been published showing an association with mortality for patients with cardiogenic shock, and the association with a pulmonary artery catheter and mortality is unknown. The aim of this study was to investigate the utilization of pulmonary artery catheters (PACs) in the intensive care unit (ICU) and to examine their association with mortality, taking into account differences between hospitals. METHODS: This is a retrospective analysis using the Japanese Intensive care PAtient Database, a multicenter, prospective, observational registry in Japanese ICUs. We included patients aged 16 years or older who were admitted to the ICU for reasons other than procedures. We excluded patients who were discharged within 24 h or had missing values. We compared the prognosis of patients with and without PAC. The primary outcome was hospital mortality. We performed propensity score analysis to adjust for baseline characteristics and hospital characteristics. RESULTS: Among 184,705 patients in this registry from April 2015 to December 2020, 59,922 patients were included in the analysis. Most patients (94.0%) with a PAC in place had cardiovascular disease. There was a wide variation in the frequency of PAC use between hospitals, from 0 to 60.3% (median 14.4%, interquartile range 2.2-28.6%). Hospital mortality was not significantly different between the PAC use group and the non-PAC use group in patients after adjustment for propensity score analysis (3.9% vs 4.3%; difference, - 0.4%; 95% CI - 1.1 to 0.3; p = 0.32). Among patients with cardiac disease, those with post-open-heart surgery and those in shock, hospital mortality was also not significantly different between the two groups (3.4% vs 3.7%, p = 0.45, 1.7% vs 1.7%, p = 0.93, 4.8% vs 4.9%, p = 0.87). CONCLUSIONS: The frequency of PAC use varied among hospitals. PAC use for ICU patients was not associated with lower hospital mortality after adjusting for differences between hospitals.

A classification system for pulmonary artery catheters.

Flow-directed, balloon-tipped pulmonary artery catheters allow measuring cardiac output and other haemodynamic variables including intracardiac pressures. We propose classifying pulmonary artery catheters by generations and specifying additional measurement modalities. Based on the method used to measure cardiac output, pulmonary artery catheters can be classified into three generations: first-generation using intermittent pulmonary artery thermodilution; second-generation using a thermal filament for automated pulmonary artery thermodilution; and third-generation combining thermal filament-based automated pulmonary artery thermodilution and pulmonary artery pulse wave analysis. Each of these pulmonary artery catheter generations can include additional measurements, such as continuous mixed venous oxygen saturation, right ventricular ejection fraction and end-diastolic volume, and right ventricular pressure. This classification should help define indications for pulmonary artery catheters in clinical practice and research.

A Patient with Class III Obesity and a Body Mass Index of 70.1 kg/m² Requiring Pulmonary Artery Catheterization to Confirm the Diagnosis of Pulmonary Hypertension.

BACKGROUND Intensive care management of patients with morbid obesity has been linked to a higher mortality rate than that of the normal population and can be challenging. Obesity is a recognized risk factor for pulmonary hypertension, but it can prevent cardiac imaging. This report presents the case of a 28-year-old man with class III (morbid) obesity, a body mass index (BMI) of 70.1 kg/m², and heart failure, requiring pulmonary artery catheterization (PAC) to confirm the diagnosis of pulmonary hypertension. CASE REPORT A 28-year-old male patient with a a body mass index (BMI) of 70.1 kg/m² was admitted to the Intensive Care Unit (ICU) for the management of respiratory and cardiac failure. The patient had class III obesity (BMI >50 kg/m²) and heart failure. Due to the difficulties in evaluating hemodynamic status via echocardiography, a pulmonary artery catheter (PAC) was placed, revealing a mean pulmonary artery pressure of 49 mmHg, and a diagnosis of pulmonary hypertension was made. The alveolar partial pressures of oxygen and carbon dioxide were optimized by ventilatory management to reduce pulmonary vascular resistance. The patient was extubated on day 23 and was discharged from the ICU on day 28. CONCLUSIONS Pulmonary hypertension should be considered in the evaluation of obese patients. Using a PAC during the intensive care management of a patient with obesity could aid in the diagnosis of pulmonary hypertension as well as cardiac dysfunction, determine treatment strategies, and evaluate hemodynamic responses to various therapies.

Prospective Evaluation of a Multibeat Analysis Cardiac Index Estimation in Patients With Cardiogenic Shock.

OBJECTIVES: The decision algorithm for managing patients in cardiogenic shock depends on cardiac index (CI) estimates. Cardiac index estimation via thermodilution (CI-TD) using a pulmonary artery catheter is used commonly for obtaining CI in these patients. Minimally invasive methods of estimating CI, such as multibeat analysis (CI-MBA), may be an alternative in this population. DESIGN: A prospective, observational study. SETTING: Cardiac intensive care unit. PARTICIPANTS: Twenty-two subjects in cardiogenic shock provided 101 paired CI measurements. INTERVENTIONS: Measurements were obtained concomitantly by intermittent CI-TD and CI-MBA (Argos Cardiac Output Monitor; Retia Medical, Valhalla, NY). For each CI-TD, CI-MBA estimates were averaged over 1 minute to provide paired values. Bland-Altman and 4-quadrant analyses were performed by plotting changes between successive CI measurements (ΔCI) from each of the 2 methods. Concordance was calculated as a percentage using ΔCI data points from the 2 methods, outside an exclusion zone of 15%. MEASUREMENTS AND MAIN RESULTS: The correlation coefficient between CI-MBA and CI-TD was 0.78 across patients. Mean CI-TD was 2.19 ± 0.46 L/min/m2 and mean CI-MBA was 2.38 ± 0.59 L/min/m2. The mean difference between CI-MBA and CI-TD (bias ± SD) was 0.20 ± 0.47 L/min/m2, and the limits of agreement were -0.72 to 1.11 L/min/m2. The percentage error was 40.0%. The concordance rate was 94%. A secondary analysis of a subgroup of patients during periods of arrhythmia demonstrated a similar accuracy of performance of CI-MBA. CONCLUSIONS: Cardiac index-MBA is not interchangeable with CI-TD. However, CI-MBA provides reasonable correlation and clinically acceptable trending ability compared with CI-TD. Cardiac output-MBA may be useful in trending changes in CI in patients with cardiogenic shock, especially in those whose pulmonary artery catheterization placement carries a high risk or is unobtainable.

Clinical impact of pulmonary artery catheter in patients with cardiogenic shock: A systematic review and meta-analysis.

BACKGROUND: The clinical utility of the pulmonary artery catheter (PAC) for the management of cardiogenic shock (CS) remains controversial. We performed a systematic review and meta-analysis exploring the association between PAC use and mortality among patients with CS. METHODS: Published studies of patients with CS treated with or without PAC hemodynamic guidance were retrieved from MEDLINE and PubMed databases from January 1, 2000, to December 31, 2021. The primary outcome was mortality, which was defined as a combination of in-hospital mortality and 30-day mortality. Secondary outcomes assessed 30-day and in-hospital mortality separately. To assess the quality of nonrandomized studies, the Newcastle-Ottawa Scale (NOS), a well-established scoring system was used. We analyzed outcomes for each study using NOS with a threshold value of >6, indicating high quality. We also performed analyses based on the countries of the studies conducted. RESULTS: Six studies with a total of 930,530 patients with CS were analyzed. Of these, 85,769 patients were in the PAC-treated group, and 844,761 patients did not receive a PAC. PAC use was associated with a significantly lower risk of mortality (PAC: 4.6 % to 41.5 % vs control: 18.8 % to 51.0 %) (OR 0.63, 95 % CI: 0.41-0.97, I2 = 0.96). Subgroup analyses demonstrated no difference in the risk of mortality between NOS ≥ 6 studies and NOS < 6 studies (p-interaction = 0.57), 30-day and in-hospital mortality (p-interaction = 0.83), or the country of origin of studies (p-interaction = 0.08). CONCLUSIONS: The use of PAC in patients with CS may be associated with decreased mortality. These data support the need for a randomized controlled trial testing the utility of PAC use in CS.

The pulmonary artery catheter.

PURPOSE OF REVIEW: To review recently published data on pulmonary artery catheter (PAC) use in critically ill patients and consider optimal use of the PAC in personalized clinical practice. RECENT FINDINGS: Although PAC use has decreased considerably since the mid-1990s, PAC-derived variables can still have an important role in elucidating hemodynamic status and directing management in complex patients. Recent studies have suggested benefit, notably in patients having cardiac surgery. SUMMARY: Only a small number of acutely ill patients require a PAC and insertion should be individualized based on clinical context, availability of trained staff, and the possibility that measured variables will be able to help guide therapy.

[Consensus on the operation of pulmonary artery catheterization].

Right heart catheterization(RHC) is a technique of inserting a catheter into the right heart and pulmonary artery via a peripheral vein, to evaluate hemodynamics and oxygen dynamics. When Swan-Ganz catheter is used, it is called pulmonary artery catheterization (PAC). PAC plays an important role in the diagnosis and evaluation of pulmonary hypertension (PH), and hemodynamic assessment of critically ill patients. We developed this consensus to improve the overall quality of RHC operation, especially the PAC standardization in the diagnosis and evaluation of PH, thereby to promote the diagnosis and treatment of PH in China.

Early pulmonary artery catheterization is not associated with survival benefits in critically ill patients with cardiac disease: An analysis of the MIMIC-IV database.

BACKGROUND: Many studies demonstrated no improved survival in patients with pulmonary artery catheter placement. However, no consistent conclusions have been drawn regarding the impact of pulmonary artery catheter in critically ill patients with heart disease. This study aimed to investigate the association of early pulmonary artery catheter use with 28-day mortality in that population. METHODS: The Multiparameter Intelligent Monitoring in Intensive Care IV (MIMIC-IV) database, a single-center critical care database, was employed to investigate this issue. This study enrolled a total of 11,887 critically ill patients with cardiac disease with or without pulmonary artery catheter insertion. The primary outcome was 28-day mortality. The multivariate regression was modeled to examine the association between pulmonary artery catheter and outcomes. Additionally, we examined the effect modification by cardiac surgeries. Propensity score matching was conducted to validate our findings. RESULTS: No improvement in 28-day mortality was observed among the pulmonary artery catheter group compared to the non-pulmonary artery catheter group (odds ratio 95% confidence interval: 1.18 [1.00-1.38], P = .049). When stratified by cardiac surgeries, the results were consistent. The patients in the pulmonary artery catheter group had fewer ventilation-free days and vasopressor-free days than those in the nonpulmonary artery catheter group after surgery stratification. In the surgical patients, pulmonary artery catheter insertion was not associated with the occurrence of acute kidney injury, and it was associated with a higher daily fluid input (mean difference 95% confidence interval: 0.13 [0.05-0.20], P = .001). In nonsurgical patients, the pulmonary artery catheter group had a higher risk of acute kidney injury occurrence (odds ratio 95% confidence interval: 1.94 [1.32-2.84], P = .001). CONCLUSION: Early pulmonary artery catheter placement is not associated with survival benefits in critically ill patients with cardiac diseases, either in surgical or nonsurgical patients.