Implications of Mean Pulmonary Arterial Wedge Pressure Trajectories in Pulmonary Arterial Hypertension.

Rationale: The mean pulmonary arterial wedge pressure (mPAWP) is the critical hemodynamic factor differentiating group 1 pulmonary arterial hypertension (PAH) from group 2 pulmonary hypertension associated with left heart disease. Despite the discrepancy between the mPAWP upper physiologic normal and current PAH definitions, the implications of the initial mPAWP for PAH clinical trajectory are poorly understood. Objectives: To model longitudinal mPAWP trajectories in PAH over 10 years and examine the clinical and hemodynamic factors associated with trajectory membership. Methods: Adult patients with PAH with two or more right heart catheterizations were identified from a multiinstitution healthcare system in eastern Massachusetts. mPAWP trajectories were constructed via group-based trajectory modeling. Feature selection was performed in least absolute shrinkage and selection operator regression. Logistic regression was used to assess associations between trajectory membership, baseline characteristics, and transplant-free survival. Measurements and Main Results: Among 301 patients with PAH, there were two distinct mPAWP trajectories, termed "mPAWP-high" (n = 71; 23.6%) and "mPAWP-low" (n = 230; 76.4%), based on the ultimate mPAWP value. Initial mPAWP clustered around median 12 mm Hg (interquartile range [IQR], 8-14 mm Hg) in the mPAWP-high and 9 mm Hg (IQR, 6-11 mm Hg) in the mPAWP-low trajectories (P < 0.001). After feature selection, initial mPAWP ⩾12 mm Hg predicted an mPAWP-high trajectory (odds ratio, 3.2; 95% confidence interval, 1.4-6.1; P = 0.0006). An mPAWP-high trajectory was associated with shorter transplant-free survival (vs. mPAWP-low, median, 7.8 vs. 11.3 yr; log-rank P = 0.017; age-adjusted P = 0.217). Conclusions: Over 10 years, the mPAWP followed two distinct trajectories, with 25% evolving into group 2 pulmonary hypertension physiology. Using routine baseline data, longitudinal mPAWP trajectory could be predicted accurately, with initial mPAWP ⩾12 mm Hg as one of the strongest predictors.

Impact of coronary hyperemia on collateral flow correction of coronary microvascular resistance indices.

Recently, a novel method to estimate wedge pressure (Pw)-corrected minimal microvascular resistance (MR) was introduced. However, this method has not been validated since, and there are some theoretical concerns regarding the impact of different physiological conditions on the derivation of Pw measurements. This study sought to validate the recently introduced method to estimate Pw-corrected MR in a Doppler-derived study population and to evaluate the impact of different physiological conditions on the Pw measurements and the derivation of Pw-corrected MR. The method to derive "estimated" hyperemic microvascular resistance (HMR) without the need for Pw measurements was validated by estimating the coronary fractional flow reserve (FFRcor) from myocardial fractional flow reserve (FFRmyo) in a Doppler-derived study population (N = 53). From these patients, 24 had hyperemic Pw measurements available for the evaluation of hyperemic conditions on the derivation of Pw and its effect on the derivation of both "true" (with measured Pw) and "estimated" Pw-corrected HMR. Nonhyperemic Pw differed significantly from Pw measured in hyperemic conditions (26 ± 14 vs. 35 ± 14 mmHg, respectively, P < 0.005). Nevertheless, there was a strong linear relationship between FFRcor and FFRmyo in nonhyperemic conditions (R2 = 0.91, P < 0.005), as well as in hyperemic conditions (R2 = 0.87, P < 0.005). There was a strong linear relationship between "true" HMR and "estimated" HMR using either nonhyperemic (R2 = 0.86, P < 0.005) or hyperemic conditions (R2 = 0.85, P < 0.005) for correction. In contrast to a modest agreement between nonhyperemic Pw-corrected HMR and apparent HMR (R2 = 0.67, P < 0.005), hyperemic Pw-corrected HMR showed a strong agreement with apparent HMR (R2 = 0.88, P < 0.005). We validated the calculation method for Pw-corrected MR in a Doppler velocity-derived population. In addition, we found a significant impact of hyperemic conditions on the measurement of Pw and the derivation of Pw-corrected HMR.NEW & NOTEWORTHY The following are what is known: 1) wedge-pressure correction is often considered for the derivation of indices of minimal microvascular resistance, and 2) the Yong method for calculating wedge pressure-corrected index of microvascular resistance (IMR) without balloon inflation has never been validated in a Doppler-derived population and has not been tested under different physiological conditions. This study 1) adds validation for the Yong method for calculated wedge-pressure correction in a Doppler-derived study population and 2) shows significant influence of the physiological conditions on the derivation of coronary wedge pressure.

Pulmonary Artery Diastolic Pressure as a Surrogate for Pulmonary Capillary Wedge Pressure in Cardiogenic Shock.

BACKGROUND: It is common for clinicians to use the pulmonary artery diastolic pressure (PADP) as a surrogate for the pulmonary capillary wedge pressure (PCWP). Here, we determine the validity of this relationship in patients with various phenotypes of cardiogenic shock (CS). METHODS AND RESULTS: In this analysis of the Critical Care Cardiology Trials Network registry, we identified 1225 people admitted with CS who received pulmonary artery catheters. Linear regression, Bland-Altman and receiver operator characteristic analyses were performed to determine the strength of the association between PADP and PCWP in patients with left-, right-, biventricular, and other non-myocardia phenotypes of CS (eg, arrhythmia, valvular stenosis, tamponade). There was a moderately strong correlation between PADP and PCWP in the total population (r = 0.64, n = 1225) and in each CS phenotype, except for right ventricular CS, for which the correlation was weak (r = 0.43, n = 71). Additionally, we found that a PADP ≥ 24 mmHg can be used to infer a PCWP ≥ 18 mmHg with ≥ 90% confidence in all but the right ventricular CS phenotype. CONCLUSIONS: This analysis validates the practice of using PADP as a surrogate for PCWP in most patients with CS; however, it should generally be avoided in cases of right ventricular-predominant CS.

Post-exercise left atrial conduit strain predicted hemodynamic change in heart failure with preserved ejection fraction.

OBJECTIVES: Left ventricle function directly impacts left atrial (LA) conduit function, and LA conduit strain is associated with exercise intolerance in patients with heart failure with preserved ejection fraction (HFpEF). Pulmonary capillary wedge pressure (PCWP) before and during exercise is the current gold standard for diagnosing HFpEF. Post-exercise ΔPCWP can lead to worse long-term outcomes. This study examined the correlation between LA strain and post-exercise ΔPCWP in patients with HFpEF. METHODS: We enrolled 100 subjects, including 74 with HFpEF and 26 with non-cardiac dyspnea, from November 2017 to December 2020. Subjects underwent echocardiography, invasive cardiac catheterization, and expired gas analysis at rest and during exercise. Arterial blood pressure, right atrial pressure, pulmonary artery pressure, and PCWP were recorded during cardiac catheterization. Cardiac output, stroke volume, pulmonary vascular resistance, pulmonary artery compliance, systemic vascular resistance, and LV stroke work were calculated using standard formulas. RESULTS: Exercise LA conduit strain significantly correlated with both post-exercise ΔPCWP (r = - 0.707, p < 0.001) and exercise PCWP (r = - 0.659; p < 0.001). Exercise LA conduit strain differentiated patients who did and did not meet the 2016 European Society of Cardiology HFpEF criteria with an area under the curve of 0.69 (95% confidence interval, 0.548-0.831) using a cutoff value of 14.25, with a sensitivity of 0.64 and a specificity of 0.68. CONCLUSIONS: Exercise LA conduit strain significantly correlates with post-exercise ΔPCWP and has a comparable power to identify patients with HFpEF. Additional studies are warranted to confirm the ability of LA conduit strain to predict long-term outcomes among patients with HFpEF. CLINICAL RELEVANCE STATEMENT: Exercise left atrial conduit strain was highly associated with the difference of post-exercise pulmonary capillary wedge pressure and may indicate increased mortality risk in patients with heart failure with preserved ejection fraction, and also has comparable diagnostic ability. KEY POINTS: • Left atrial conduit strain is associated with exercise intolerance in patients with heart failure with preserved ejection fraction. • Left atrial conduit strain during exercise can identify patients with heart failure with preserved ejection fraction. • Exercise left atrial conduit strain significantly correlates with the difference of pulmonary capillary wedge pressure during and before exercise which might predict the long-term outcomes of heart failure with preserved ejection fraction patients.

Rest and exercise-stress estimated pulmonary capillary wedge pressure using real-time free-breathing cardiovascular magnetic resonance imaging.

BACKGROUND: Identification of increased pulmonary capillary wedge pressure (PCWP) by right heart catheterization (RHC) is the reference standard for the diagnosis of heart failure with preserved ejection fraction (HFpEF). Recently, cardiovascular magnetic resonance (CMR) imaging estimation of PCWP at rest was introduced as a non-invasive alternative. Since many patients are only identified during physiological exercise-stress, we hypothesized that novel exercise-stress CMR-derived PCWP emerges superior compared to its assessment at rest. METHODS: The HFpEF-Stress Trial prospectively recruited 75 patients with exertional dyspnea and diastolic dysfunction who then underwent rest and exercise-stress RHC and CMR. HFpEF was defined according to PCWP (overt HFpEF ≥15 mmHg at rest, masked HFpEF ≥25 mmHg during exercise-stress). CMR-derived PCWP was calculated based on previously published formula using left ventricular mass and either biplane left atrial volume (LAV) or monoplane left atrial area (LAA). RESULTS: LAV (rest/stress: r = 0.50/r = 0.55, p < 0.001) and LAA PCWP (rest/stress: r = 0.50/r = 0.48, p < 0.001) correlated significantly with RHC-derived PCWP while numerically overestimating PCWP at rest and underestimating PCWP during exercise-stress. LAV and LAA PCWP showed good diagnostic accuracy to detect HFpEF (area under the receiver operating characteristic curve (AUC) LAV rest 0.73, stress 0.81; LAA rest 0.72, stress 0.77) with incremental diagnostic value for the detection of masked HFpEF using exercise-stress (AUC LAV rest 0.54 vs stress 0.67, p = 0.019, LAA rest 0.52 vs stress 0.66, p = 0.012). LAV but not LAA PCWP during exercise-stress was a predictor for 24 months hospitalization independent of a medical history for atrial fibrillation (hazard ratio (HR) 1.26, 95% confidence interval 1.02-1.55, p = 0.032). CONCLUSION: Non-invasive PCWP correlates well with the invasive reference at rest and during exercise stress. There is overall good diagnostic accuracy for HFpEF assessment using CMR-derived estimated PCWP despite deviations in absolute agreement. Non-invasive exercise derived PCWP may particularly facilitate detection of masked HFpEF in the future.

Correlation Between Tissue Doppler Imaging Method (E/e') and Invasive Measurements of Left Ventricular Filling Pressures: A Systematic Review, Meta-Analysis, and Meta-Regression.

OBJECTIVES: Evaluation of pulmonary capillary wedge pressure (PCWP) through right heart catheterization can indirectly provide an estimation of the filling pressure of the left ventricle. Echocardiography can estimate left ventricular compliance using mitral annular tissue Doppler imaging (TDI). The E/e' ratio refers to the correlation between the peak mitral inflow (E-wave) velocity and early diastolic tissue Doppler mitral annular velocity (e'). The main purpose of this systematic review was to establish the correlation between echocardiographic E/e' ratio and PCWP. The correlation between E/e' and left ventricular end-diastolic pressure (LVEDP) was evaluated as a secondary objective. DESIGN: A systematic review and meta-analysis of observational studies was conducted. The search was based on Medline (PubMed), Scopus, and Web of Science. SETTING: Intensive care unit or cardiac intensive care unit. PARTICIPANTS: Adult patients. INTERVENTIONS: Any study comparing the left ventricular filling pressure obtained by cardiac catheterization (reference) and echocardiographic evaluation, in particular TDI analysis (intervention), were included. MEASUREMENTS AND MAIN RESULTS: The pooled analysis included 94 studies from the initially identified 7,304 records. The correlation was 0.48 (95% CI 0.42-0.54, Q = 420.52, I2 = 84.8%) for PCWP and 0.50 (95% CI 0.38-0.60, Q = 210.91, I2 = 89.1%) for LVEDP. CONCLUSIONS: The E/e' ratio moderately correlated with PCWP/LVEDP. The correlation was stable irrespective of the sites where e' was measured, but each site has its own limitations for specific patient subpopulations. The correlation was weak in patients with heart failure with a preserved ejection fraction.

Combined pre- and post-capillary pulmonary hypertension in left heart disease.

Patients with heart failure (HF) often have pulmonary hypertension (PH), which is mainly post-capillary; however, some of them also develop a pre-capillary component. The exact mechanisms leading to combined pre- and post-capillary PH are not yet clear, but the phenomenon seems to start from a passive transmission of increased pressure from the left heart to the lungs, and then continues with the remodeling of both the alveolar and vascular components through different pathways. More importantly, it is not yet clear which patients are predisposed to develop the disease. These patients have some characteristics similar to those with idiopathic pulmonary arterial hypertension (e.g., young age and frequent incidence in female gender), but they share cardiovascular risk factors with patients with HF (e.g., obesity and diabetes), with both reduced and preserved ejection fraction. Thanks to echocardiography parameters and newly introduced scores, more tools are available to distinguish between idiopathic pulmonary arterial hypertension and combined PH and to guide patients' management. It may be hypothesized to treat patients in whom the pre-capillary component is predominant with specific therapies such as those for idiopathic pulmonary arterial hypertension; however, no adequately powered trials of PH-specific treatment are available in combined PH. Early evidence of clinical benefit has been proven in some trials on phosphodiesterase type 5 inhibitors, while data on prostacyclin analogues, endothelin-1 receptor antagonists, and soluble guanylate cyclase stimulators are still controversial.

Echocardiographic assessment of pulmonary capillary wedge pressure in patients with frequent premature ventricular complexes.

BACKGROUND: Premature ventricular complex (PVC) is seen in most individuals. It has been shown that the kinetics-tracking index or Kawasaki-Tanaka index (KT index) strongly predicts pulmonary capillary wedge pressure (PCWP) by noninvasively. KT index was defined as log10 (active LAEF/minimum LAV index). We goaled to assess PCWP non-invasively in patients with frequent PVCs with normal left ventricular systolic functions and to evaluate whether there is an increase in PCWP before systolic and diastolic functions are impaired. METHODS: About 55 patients with frequent PVCs as a patient group and 54 healthy volunteers as a control group were involved to the study. After the conventional echocardiographic examination, the vendor-independent software system (EchoPAC version 202) was used to obtain the time-left atrial volume (LAV) curve. total left atrial emptying function (LAEF), passive LAEF, and active LAEF were calculated to evaluate phasic left atrial (LA) function. In this study, ePCWP was calculated using the KT index, and KT index results and other echocardiographic parameters were compared between study groups. RESULTS: LA anterior-posterior dimension, LA maximum volume index, and LA minimum volume index were significantly larger in the patient group (all p values < .001). Total LAEF were significantly reduced in patients with frequent PVC (p < .001). Estimated pulmonary capillary wedge pressure (ePCWP) by KT index was significantly higher in patients with frequent PVCs (p < .001). CONCLUSIONS: Patients with frequent PVC had increased ePCWP as assessed by KT index.

Pulmonary artery flotation catheter (PAFC) combined with pump-controlled retrograde trial off (PCRTO) as a trial for weaning VA-ECMO patients: A retrospective study.

OBJECTIVES: Pump-controlled retrograde trial off (PCRTO) has been recently proposed as an effective and safe VA-ECMO weaning method. However, reports of haemodynamic monitoring during PCRTO are rare. Therefore, the purpose of this study was to investigate the changes in the left and right heart function during the PCRTO process combined with a pulmonary artery flotation catheter (PAFC). METHODS: Between March 2019 and May 2021, 20 adult VA-ECMO patients who underwent PCRTO in combination with PAFC were enrolled in this study. The patients' general characteristics, PCRTO results, haemodynamic parameters during PCRTO progression, complications, and clinical prognoses were analysed. Those who survived for 48 h after withdrawal and did not require ECMO assistance were defined as the success group, and those who did not survive for 48 h after withdrawal or who required ECMO assistance were defined as the failure group. RESULTS: Of the 20 patients, 13 (65%) were included in the success group, and 7 (35%) were included in the failure group. Compared with the success group, the heart rate (HR) of the failure group was significantly increased 30 min after PCRTO (p < .01), and the pulmonary artery wedge pressure (PAWP) was significantly higher at all time points (p < .01). Compared with pre-PCRTO in the success group, the HR at 2 min in the success group was significantly increased, but decreased to the baseline levels at 15 min and 30 min. The PAWP was also significantly increased at 2 min, but decreased at 15 min and dropped to the baseline level at 30 min in the success group. Compared with pre-PCRTO in the failure group, the HR and PAWP increased significantly at 2 min, 15 min and 30 min in the failure group. No new embolism-related complications were found in the success group after the withdrawal from ECMO. CONCLUSIONS: PCRTO is a safe and reliable VA-ECMO weaning method. Combined with haemodynamic monitoring through PAFC, PCRTO can better assess the cardiac reserve function.

Estimation of Physiologic Pressures: Invasive and Non-Invasive Techniques, AI Models, and Future Perspectives.

The measurement of physiologic pressure helps diagnose and prevent associated health complications. From typical conventional methods to more complicated modalities, such as the estimation of intracranial pressures, numerous invasive and noninvasive tools that provide us with insight into daily physiology and aid in understanding pathology are within our grasp. Currently, our standards for estimating vital pressures, including continuous BP measurements, pulmonary capillary wedge pressures, and hepatic portal gradients, involve the use of invasive modalities. As an emerging field in medical technology, artificial intelligence (AI) has been incorporated into analyzing and predicting patterns of physiologic pressures. AI has been used to construct models that have clinical applicability both in hospital settings and at-home settings for ease of use for patients. Studies applying AI to each of these compartmental pressures were searched and shortlisted for thorough assessment and review. There are several AI-based innovations in noninvasive blood pressure estimation based on imaging, auscultation, oscillometry and wearable technology employing biosignals. The purpose of this review is to provide an in-depth assessment of the involved physiologies, prevailing methodologies and emerging technologies incorporating AI in clinical practice for each type of compartmental pressure measurement. We also bring to the forefront AI-based noninvasive estimation techniques for physiologic pressure based on microwave systems that have promising potential for clinical practice.

Pulmonary Artery Wedge Pressure Formula Using Echocardiography Finding.

This study aims to introduce a new formula for pulmonary artery wedge pressure (PAWP) derived from the pathophysiology of Velocity A (VA) waves. The current formula is the the Nagueh formula. Left ventricular (LV) filling is described as a velocity A (VA) wave. The VA wave represents the filling rate of the end-diastolic blood phase from the left atrium (LA) to the LV which can be determined on echocardiography. Left ventricular end diastolic pressure (LVEDP) is equivalent to LA pressure and is also equivalent to PAWP. The gold standard method for obtaining PAWP values is right heart catheterization. By measuring the VA waves in the bloodstream, a new PAWP formula is obtained, and the PAWP examination can be validated in research and can be compared with several other PAWP formulas that are currently the world's standard formula for calculating pulmonary artery wedge pressure (PAWP).The new PAWP formula is obtained from the conversion of the VA wave. This formula could be validated further in research and used in clinical practice.

The Role of New Pulmonary Artery Wedge Pressure Formula to Predict Diastolic Dysfunction in Obstructive Sleep Apnea.

BACKGROUND: Heart failure (HF) is a common condition with high morbidity and mortality  in  Obstructive Sleep Apnea (OSA), especially in obese patient. The causes of HF are often abnormal conduction pathways, pump filling and/or heart valves. Right heart catheterization using Swan-Ganz catheter remains the gold standard to determine pulmonary hemodynamics, but it is costly and invasive. Herein, we propose a new formula for non-invasive Pulmonary artery wedge pressure (PAWP) measurement using tissue Doppler echocardiography. The purpose of this research is to explore the correlation between the new formula to calculate PAWP to predict diastolic dysfunction in OSA patients. METHODS: A cross-sectional study was conducted in Jakarta, in March until October 2021. Eighty-two subjects were enrolled in the study, consist of 34 females and 48 males. All subjects underwent polysomnography and tissue Doppler echocardiography. Noninvasive measurement of PAWP were obtained from combined assessment of E/e' and left atrial parameters. RESULTS: Based on 82 subjects included, 66 subjects (80.5%) had obstructive sleep apnea, and 16 subjects (19.5%) did not have it. There was a significant difference in PAWP between patients with and without OSA (p value <0.01). Ten subjects OSA (12.1%) had diastolic dysfunction, while all non-OSA subjects had normal diastolic function, with no statistical significance between two groups (p value = 0.20). Diastolic dysfunction significantly associated with PAWP measured using proposed formula  (R = 0.240, p value = 0.030). CONCLUSION: The new formula could be used to indirectly calculate PAWP and predict diastolic dysfunction in OSA. Obstructive sleep apnea is associated with elevated PAWP. The increased risk of diastolic dysfunction in OSA, especially in obesity patient may indicate for the risk of cardiovascular morbidities.

Standard volume infusion unmasked diastolic dysfunction in pediatric heart transplant recipients during surveillance cardiac catheterization, but without echocardiographic correlates.

BACKGROUND: Adult experience evaluating left ventricular diastolic function (LVDFx) includes volume administration during catheterization while obtaining pulmonary capillary wedge pressures (PCWP) or left ventricular end diastolic pressures (LVEDP). Catheterization is inherently challenging in pediatric patients, making echocardiographic assessment ideal. Pediatric echocardiographic studies predicting LVDFx have variable hemodynamic and hydration conditions and have produced inconsistent results. We evaluated the association between simultaneous echocardiographic and catheterization assessment of LVDFx, using a fluid bolus for optimal loading conditions. METHODS: Prospective cohort study of pediatric heart transplant recipients receiving echocardiogram simultaneous with routine cardiac catheterization. Mitral valve inflow velocities, septal and lateral wall tissue Doppler indices, and PCWP and/or LVEDP were obtained and repeated following a 10 ml/kg bolus. Echocardiographic parameters were evaluated for an association with changes in PCWP or LVEDP following the bolus. Abnormal LVDFx was defined as PCWP or LVEDP ≥12 mm Hg. RESULTS: Twenty-nine patients underwent catheterization. Median pre-bolus PCWP and LVEDP were 11.0 mm Hg and 10.0 mm Hg, respectively. After bolus, median PCWP and LVEDP increased to 14.0 mm Hg (p < .001) and 13 mm Hg (p < .001), respectively. Of 21 patients with normal pre-bolus catheterization hemodynamics, 14 (66.7%) increased to abnormal following fluid bolus. Using area under an ROC, no echocardiographic parameter of LVDFx, or their ratios, were associated with predetermined abnormal LVEDP and/or PCWP. CONCLUSION: After bolus, our cohort demonstrated significant increases in LVEDP and/or PCWP, unmasking diastolic dysfunction. Fluid challenges should be considered in pediatric patients undergoing cardiac catheterization with suspected diastolic dysfunction. Echocardiographic measurements were unable to discriminate between normal and abnormal LVEDP and/or PCWP.

The Differential Impact of the Left Atrial Pressure Components on Pulmonary Arterial Compliance-Resistance Relationship in Heart Failure.

BACKGROUND: An increase in the pulmonary capillary wedge pressure (PAWP) has been shown to impact on the inherent relationship between the pulmonary arterial compliance (PAC) and pulmonary vascular resistance (PVR), thus augmenting the pulsatile relative to the resistive load of the right ventricle. However, the PAWP comprises the integration of both the steady and the pulsatile pressure components. We sought to address the differential impact of the these distinct PAWP components on the PAC-PVR relationship in a cohort of patients with heart failure. METHODS AND RESULTS: The study population consisted of 192 patients with hemodynamic findings diagnostic for heart failure. Off-line analysis was performed using the MATLAB software. The steady and pulsatile PAWP components were calculated as mid-A pressure and mean pressure during the V-wave oscillation, respectively. The PAC and PVR were hyperbolically and inversely associated and the subgroup of patients with PAWP above the median (>18 mm Hg) displayed a significant left and downward shift of the curve fit (P < .001). The shift in the PAC-PVR fit between patients with higher versus low steady PAWP was not significant (P = .43). In contrast, there was a significant downward and leftward shift of the PVR-PAC curve fit for the subgroup with a higher pulsatile PAWP (P < .001). Furthermore, only the pulsatile PAWP was significantly associated with the time-constant of the pulmonary circulation, assessed as the PAC × PVR product (P < .001). CONCLUSIONS: In patients with heart failure, the pulsatile rather than the steady PAWP component stands for the previously documented shift of the PAC-PVR relationship occurring at an elevated PAWP.

Hemodynamic changes during transcatheter atrial septal defect closure predict midterm heart failure deterioration in adults.

OBJECTIVES: To investigate whether hemodynamic changes during balloon occlusion test (BOT) predict future heart failure (HF) deterioration after transcatheter atrial septal defect closure (tASD-closure). BACKGROUND: Midterm HF deterioration can sometimes occur after tASD-closure in adults. Whether hemodynamic changes during tASD-closure can help identify patients at risk is unknown. METHODS: This prospective observational study enrolled 86 consecutive adult patients who underwent tASD-closure. Hemodynamic parameters, including pulmonary capillary wedge pressure (PCWP), were measured at baseline, during BOT, and after tASD-closure. The changes in PCWP during BOT and after tASD-closure were defined as ΔPCWP (Occ-Pre) and ΔPCWP (Post-Pre), respectively. Clinical parameters were evaluated before tASD-closure and during the 3-month follow-up. We assessed the occurrence of HF deterioration (HF requiring hospitalization or additional diuretics) during a 2-year follow-up period and categorized patients into HF (+) and HF (-) groups accordingly. The aforementioned parameters were compared between groups. RESULTS: Midterm HF deterioration occurred in 12 patients (13.9%). Compared to the HF (-) group, the HF (+) group presented a significantly higher ΔPCWP (Occ-Pre) (9.5 ± 4.4 mmHg vs. 3.0 ± 3.3 mmHg; p < 0.001) and ΔPCWP (Post-Pre) (4.0 ± 2.8 mmHg vs. 0.6 ± 1.8 mmHg; p = 0.004). Receiver operating characteristic curve analysis showed that the ΔPCWP (Occ-Pre) cutoff value of 5.5 mmHg had excellent ability to predict HF deterioration (Area under the curve 0.886 [0.779-0.993], p < 0.001; sensitivity 0.917, specificity 0.824). CONCLUSIONS: Increases in PCWP during BOT predict midterm HF deterioration after tASD-closure. Close surveillance may be needed in patients with a ΔPCWP (Occ-Pre) >5 mmHg.

Proposal of selective wedge instillation of pulmonary surfactant for COVID-19 pneumonia based on computational fluid dynamics simulation.

BACKGROUND: The most important target cell of SARS-CoV-2 is Type II pneumocyte which produces and secretes pulmonary surfactant (PS) that prevents alveolar collapse. PS instillation therapy is dramatically effective for infant respiratory distress syndrome but has been clinically ineffective for ARDS. Nowadays, ARDS is regarded as non-cardiogenic pulmonary edema with vascular hyper-permeability regardless of direct relation to PS dysfunction. However, there is a possibility that this ineffectiveness of PS instillation for ARDS is caused by insufficient delivery. Then, we performed PS instillation simulation with realistic human airway models by the use of computational fluid dynamics, and investigated how instilled PS would move in the liquid layer covering the airway wall and reach to alveolar regions. METHODS: Two types of 3D human airway models were prepared: one was from the trachea to the lobular bronchi and the other was from a subsegmental bronchus to respiratory bronchioles. The thickness of the liquid layer covering the airway was assigned as 14 % of the inner radius of the airway segment. The liquid layer was assumed to be replaced by an instilled PS. The flow rate of the instilled PS was assigned a constant value, which was determined by the total amount and instillation time in clinical use. The PS concentration of the liquid layer during instillation was computed by solving the advective-diffusion equation. RESULTS: The driving pressure from the trachea to respiratory bronchioles was calculated at 317 cmH2O, which is about 20 times of a standard value in conventional PS instillation method where the driving pressure was given by difference between inspiratory and end-expiratory pressures of a ventilator. It means that almost all PS does not reach the alveolar regions but moves to and fro within the airway according to the change in ventilator pressure. The driving pressure from subsegmental bronchus was calculated at 273 cm H2O, that is clinically possible by wedge instillation under bronchoscopic observation. CONCLUSIONS: The simulation study has revealed that selective wedge instillation under bronchoscopic observation should be tried for COVID-19 pneumonia before the onset of ARDS. It will be also useful for preventing secondary lung fibrosis.

Characteristics of patients meeting the new definition of pre-capillary pulmonary hypertension (Nice 2018) in a single Japanese pulmonary hypertension center.

BACKGROUND: The 6th World Symposium on Pulmonary Hypertension (Nice 2018) proposed a new definition of pre-capillary pulmonary hypertension (PH) as a condition with mean pulmonary artery pressure (mPAP) > 20 mmHg, pulmonary artery wedge pressure ≤ 15 mmHg, and pulmonary vascular resistance (PVR) ≥ 3 Wood units (WU). The characteristics and prognosis of patients with pre-capillary PH, according to this new definition, is unclear. Therefore, we determined the characteristics and survival of patients with borderline pre-capillary PH. METHODS: We retrospectively enrolled 683 patients who underwent their first right heart catheterization at Chiba University, Japan. Among them, 489 patients met the pre-capillary PH requirement with mPAP ≥ 25 mmHg (conventional pre-capillary PH group), while 22 patients met the borderline pre-capillary PH criteria (borderline pre-capillary PH group). Additionally, 16 patients with a mean PAP of 20-25 and PVR of 2-3 WU were also examined. RESULTS: The borderline pre-capillary PH group comprised 4.3% of the total patients with pre-capillary PH, and the majority was in Group 3 (40.9%) or 4 (45.5%). The survival of the borderline pre-capillary PH group tended to be better than that of the conventional pre-capillary PH group. The prognosis of Group3 PH was the worst among the patients with borderline precapillary PH. There was no significant difference in survival between the borderline pre-capillary PH group with PVR ≥ 3 WU and that with PVR of 2-3 2WU, although none of the patients in the latter group died due to right heart failure. CONCLUSIONS: This is the first study conducted in a PH center in an Asian country to reveal the characteristics of patients with pre-capillary PH, according to the Nice 2018 definition. They comprised 4.3% of the total population with pre-capillary PH, and the majority of the pre-capillary PH cases were in either Group3 or 4. The prognosis may be affected by the patients' underlying diseases. Further prospective studies are needed to determine whether the new definition, including the PVR cut-off, is beneficial in clinical practice.

Tissue Doppler Imaging (E/e') and Pulmonary Capillary Wedge Pressure in Patients With Severe Aortic Stenosis.

OBJECTIVE: Although American and European consensus statements advocate using the ratio of the transmitral E velocity and tissue Doppler early diastolic mitral annular velocity (E/e') in the assessment of left-sided heart filling pressures, recent reports have questioned the reliability of this ratio to predict left atrial pressures in a variety of disease states. The authors hypothesized that there is a clinically significant correlation between E/e' and pulmonary capillary wedge pressure (PCWP) in patients with severe aortic stenosis. DESIGN: Retrospective cohort study. PARTICIPANTS: The study comprised 733 consecutive patients with severe aortic stenosis who underwent transcatheter aortic valve replacement for severe aortic stenosis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: PCWP and E/e'ave (average of the lateral and medial annulus tissue Doppler velocities) were measured with a pulmonary artery catheter and transthoracic echocardiography during preprocedural evaluation. Patients were grouped by left ventricular ejection fraction (LVEF) ≥50% and LVEF <50%. Spearman rank correlation, analysis of variance, and t and chi-square tests were used to analyze the data. Seventy-nine patients met the inclusion criteria. There was no significant correlation between E/e'ave and PCWP (n = 79, Spearman r = 0.096; p = 0.3994). This correlation did not improve when ventricular function was considered (LVEF <50%: n = 11, Spearman r = -0.097; p = 0.776 and LVEF ≥50%: n = 68, Spearman r = 0.116; p = 0.345). There was no statistically significant difference in mean PCWP between each range of E/e'ave. CONCLUSION: A clinically relevant relationship between E/e' and PCWP was not observed in patients with severe aortic stenosis.

To Swan or Not to Swan: Indications, Alternatives, and Future Directions.

The pulmonary artery catheter (PAC) has revolutionized bedside assessment of preload, afterload, and contractility using measured pulmonary capillary wedge pressure, calculated systemic vascular resistance, and estimated cardiac output. It is placed percutaneously by a flow-directed balloon-tipped technique through the venous system and the right heart to the pulmonary artery. Interest in the hemodynamic variables obtained from PACs paved the way for the development of numerous less-invasive hemodynamic monitors over the past 3 decades. These devices estimate cardiac output using concepts such as pulse contour and pressure analysis, transpulmonary thermodilution, carbon dioxide rebreathing, impedance plethysmography, Doppler ultrasonography, and echocardiography. Herein, the authors review the conception, technologic advancements, and modern use of PACs, as well as the criticisms regarding the clinical utility, reliability, and safety of PACs. The authors comment on the current understanding of the benefits and limitations of alternative hemodynamic monitors, which is important for providers caring for critically ill patients. The authors also briefly discuss the use of hemodynamic monitoring in goal-directed fluid therapy algorithms in Enhanced Recovery After Surgery programs.

Clinical potential of hemodynamic ramp test by simultaneous echocardiography and right heart catheterization for aortic insufficiency in a patient with continuous-flow left ventricular assist device.

Aortic insufficiency (AI) is an important adverse event in patients with continuous-flow (CF) left ventricular assist device (LVAD) support. AI is often progressive, resulting in elevated 2-year morbidity and mortality. The effectiveness of echocardiographic ramp studies in patients with AI has been unclear. Here, we describe a patient with a CF-LVAD implant who underwent aortic valve replacement (AVR), following assessment of AI using a hemodynamic ramp test with simultaneous echocardiography and right heart catheterization (RHC). The patient was a 21-year-old man with cardiogenic shock due to acute myocarditis, who underwent HeartWare CF-LVAD (HVAD) implantation. Heart failure persisted despite increased doses of diuretics and inotrope, as well as an increased HVAD pump rate. HVAD monitoring revealed a correlation between increased HVAD pump rate and flow at each speed step. A hemodynamic ramp test with simultaneous transthoracic echocardiography and RHC revealed a significant discrepancy between HVAD pump flow and cardiac output (CO) at each speed step; moreover, pulmonary capillary wedge pressure remained high. Therefore, the patient underwent AVR. Subsequently, his low CO symptoms disappeared and inotropes were successfully discontinued. A postoperative hemodynamic ramp test revealed that AVR had successfully closed the loop of blood flow and reduced the discrepancy between HVAD pump flow and CO, thereby increasing CO. The patient was then discharged uneventfully. In conclusion, a hemodynamic ramp test with simultaneous echocardiography and RHC was useful for the evaluation of the causal relationship between AI and low CO, and for selection of surgical treatment for AI in a patient with CF-LVAD.