Search

Background The association between raised pulmonary artery pressures, pulmonary vascular resistance (PVR), and right‐sided heart dysfunction is well recognized. The added value of pulsatile indices, specifically pulmonary arterial compliance (PAC) and characteristic impedance, remains unclear. This study aimed to identify the optimal vascular afterload model for predicting right‐sided heart dysfunction in newly diagnosed pulmonary hypertension (PH). METHODS AND RESULTS This was a prospective cohort study of 86 patients with suspected PH (60±16 years; 66 women) who underwent right‐sided heart catheterization and cardiac magnetic resonance imaging. Right ventricular end‐diastolic volume index (RVEDVi) and right atrial (RA) volume index were measured using cardiac magnetic resonance imaging. Vascular resistance, PAC, and characteristic impedance were measured using pulmonary artery pressure from right‐sided heart catheterization and pulmonary artery flow from cardiac magnetic resonance imaging. Optimal model fit was determined by the lowest Akaike Information Criterion value. A total of 58% of patients had a right ventricular ejection fraction

Cardiopulmonary bypass (CPB) is associated with intravascular hemolysis which depletes endogenous nitric oxide (NO). The impact of hemolysis on pulmonary arterial compliance (PAC) and right ventricular systolic function has not been explored yet. We hypothesized that decreased NO availability is associated with worse PAC and right ventricular systolic function after CPB. This is a secondary analysis of an observational cohort study in patients undergoing cardiac surgery with CPB at Massachusetts General Hospital, USA (2014–2015). We assessed PAC (stroke volume/pulmonary artery pulse pressure ratio), and right ventricular function index (RVFI) (systolic pulmonary arterial pressure/cardiac output), as well as NO consumption at 15 min, 4 h and 12 h after CPB. Patients were stratified by CPB duration. Further, we assessed the association between changes in NO consumption with PAC and RVFI between 15min and 4 h after CPB. PAC was lowest at 15min after CPB and improved over time (n = 50). RVFI was highest -worse right ventricular function- at CPB end and gradually decreased. Changes in hemolysis, PAC and RVFI differed over time by CPB duration. PAC inversely correlated with total pulmonary resistance (TPR). TPR and PAC positively and negatively correlated with RVFI, respectively. NO consumption between 15min and 4 h after CPB correlated with changes in PAC (−0.28 ml/mmHg, 95%CI −0.49 to −0.01, p = 0.012) and RVFI (0.14 mmHg*L−1*min, 95%CI 0.10 to 0.18, p < 0.001) after multivariable adjustments. PAC and RVFI are worse at CPB end and improve over time. Depletion of endogenous NO may contribute to explain changes in PAC and RVFI after CPB. • Pulmonary arterial compliance (PAC) gradually increases after cardiopulmonary bypass (CPB). • PAC inversely correlates with total pulmonary resistance (TPR) after CPB. • TPR and PAC positively and negatively correlate with right ventricle function after CPB, respectively. • NO consumption, which reflects changes in hemolysis, independently correlates with PAC and right ventricle function after CPB. • Hemolysis may contribute to changes in PAC and right ventricle function after CPB. [ABSTRACT FROM AUTHOR]

Pulmonary hypertension (PH) is a common and prognostically important complication of mitral regurgitation (MR). Mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) are traditionally used to diagnose PH, however these indices measure static rather than pulsatile load, leading to an incomplete representation of pulmonary vascular load on the right ventricle (RV). Pulmonary arterial compliance (PAC) is one method for quantifying pulsatile load, and is both a stronger predictor of prognosis in left heart failure, as well as a more sensitive measure of early pulmonary vascular dysfunction than PVR. With the expansion of transcatheter mitral and tricuspid valve therapies, there is renewed interest to more accurately define the load imposed by the pulmonary vasculature on the RV, especially in the early phase, prior to the onset of chronic PH. This review discusses the pathophysiology of pH in left heart failure and MR, the utility of PAC as a measure of RV afterload, and its calculation for clinical use and interpretation, underlining the utility of PAC as an adjunct for assessing pulmonary vascular haemodynamics.

Aims: A common feature of various forms of pulmonary hypertension (PH) is progressive decline of pulmonary arterial compliance (CPA), which correlates with reduced survival. In this acute study, we evaluated feasibility, safety and haemodynamic performance of the Aria pulmonary endovascular device in patients with PH associated with left heart disease (PH‐LHD) and chronic lung disease (PH‐CLD). Methods and results: Eight patients with PH‐LHD and 10 patients with PH‐CLD were included in this study. The device was placed in the main pulmonary artery via the right femoral vein and was connected by a catheter to a gas‐filled reservoir outside the body. During systole, gas shifts from the balloon to the reservoir, leading to deflation of the balloon. In diastole, the gas returns from the reservoir to the balloon, leading to balloon inflation and enhancing diastolic blood flow to the distal pulmonary capillary bed. Haemodynamics were assessed at baseline, and again with device off, device on and device off. The primary safety endpoint was the incidence of serious adverse events through 30 days after the procedure. No complications or investigational device‐related serious adverse events occurred. Device activation in PH‐LHD and PH‐CLD patients decreased pulmonary arterial pulse pressure by 5.6 ± 4.2 mmHg (−12%; p = 0.003) and 4.2 ± 2.2 mmHg (−11%; p < 0.001), increased CPA by 0.4 ± 0.2 ml/mmHg (+23%; p = 0.004) and 0.4 ± 0.3 ml/mmHg (+25%; p = 0.001), and increased right ventricular‐to‐pulmonary vascular (RV‐PV) coupling by 0.24 ± 0.18 (+40%; p = 0.012) and 0.11 ± 0.07 (+21%; p = 0.001), respectively. Conclusions: Temporary implantation of the Aria endovascular device was feasible and safe. Device activation resulted in acute improvement of CPA and RV‐PV coupling. [ABSTRACT FROM AUTHOR]

Background: The association between raised pulmonary artery pressures, pulmonary vascular resistance (PVR), and right-sided heart dysfunction is well recognized. The added value of pulsatile indices, specifically pulmonary arterial compliance (PAC) and characteristic impedance, remains unclear. This study aimed to identify the optimal vascular afterload model for predicting right-sided heart dysfunction in newly diagnosed pulmonary hypertension (PH)., Methods and Results: This was a prospective cohort study of 86 patients with suspected PH (60±16 years; 66 women) who underwent right-sided heart catheterization and cardiac magnetic resonance imaging. Right ventricular end-diastolic volume index (RVEDVi) and right atrial (RA) volume index were measured using cardiac magnetic resonance imaging. Vascular resistance, PAC, and characteristic impedance were measured using pulmonary artery pressure from right-sided heart catheterization and pulmonary artery flow from cardiac magnetic resonance imaging. Optimal model fit was determined by the lowest Akaike Information Criterion value. A total of 58% of patients had a right ventricular ejection fraction <50%, 63% had an increased RVEDVi, and 56% had an increased RA volume index. Overall, PVR was the best predictor of right ventricular ejection fraction <50% ( P <0.01), increased RVEDVi ( P <0.01), and RA volume index ( P =0.02). However, for patients with a PVR <240 dynes.s.cm -5 , PAC clinical outperformed PVR in predicting right ventricular ejection fraction <50% ( P =0.02) and increased RVEDVi ( P =0.05). A 3-component model (PVR, PAC clinical , and characteristic impedance) best predicted RA dilatation ( P =0.05). In paired analysis, alternative methods of PAC quantification better predicted increased RVEDVi (PAC decay P =0.02) and RA volume index (PAC area P =0.02). PAC clinical <2.3 mL/mm Hg optimally predicted right-sided heart dysfunction (area under the curve, 0.768) and increased the AUC for PVR in undifferentiated/left-sided PH (0.89 versus 0.72)., Conclusions: Pulsatile vascular afterload measurement improves right-sided heart dysfunction prediction in undifferentiated/left-sided PH. More accurate PAC measurement methods could further enhance prognostic accuracy, while a PVR ≥240 dynes.s.cm -5 remains a valuable threshold for precapillary PH.

Pulmonary hypertension associated with congenital heart disease (CHD-PH) encompasses different conditions confounded by the left-to-right shunt, left heart obstruction, ventricular dysfunction, hypoxia due to airway obstruction, dysplasia/hypoplasia of the pulmonary vasculature, pulmonary vascular obstructive disease, and genetic variations of vasoactive mediators. Pulmonary input impedance consists of the pulmonary vascular resistance (Rp) and capacitance (Cp). Rp is calculated as the transpulmonary pressure divided by the pulmonary cardiac output, whereas Cp is calculated as the pulmonary stroke volume divided by the pulmonary arterial pulse pressure. The plots of Rp and Cp demonstrate a unique hyperbolic relationship, namely, the resistor–capacitor coupling curve, which represents the pulmonary vascular condition. The product of Rp and Cp is the exponential pressure decay, which refers to the time constant. Alterations in Cp are more considerable in CHD patients at an early stage of developing pulmonary hypertension or with excessive pulmonary blood flow due to a left-to-right shunt. The importance of Cp has gained attention because recent reports have shown that low Cp potentially reflects poor prognosis in patients with CHD-PH and idiopathic pulmonary hypertension. It is also known that Cp levels decrease in specific populations, such as preterm infants and trisomy 21. Therefore, both Rp and Cp should be individually evaluated in the management of children with CHD-PH who have different disease conditions.

Background: Right ventricular (RV) afterload is widely assessed by pulmonary vascular resistance (PVR). However, RV afterload is underestimated because PVR does not account for the pulsatile load. The pulsatile load is often evaluated by pulmonary arterial compliance (PAC). The RC (resistance-compliance) time, which is calculated from the product of PVR and PAC, is considered to remain constant under medical therapy. However, little is known on how RC time is affected by invasive therapy in chronic thromboembolic pulmonary hypertension (CTEPH). This study aimed to evaluate change of RC time in patients underwent pulmonary endarterectomy (PEA). Furthermore, we investigated the clinical relevance of RC time. Methods: We reviewed consecutive 50 patients except for death case underwent PEA. Baseline clinical parameters including RC time before performing PEA and follow-up were evaluated. Patients was classified as decrease or non-decrease according to change of RC time. Furthermore, we classified patients into a NYHA I group who had no symptom after treatment and a residual symptom group in order to investigate the relationship of RC time to residual symptoms. Results: RC time was significantly decreased after PEA (0.54 ± 0.16 to 0.45 ± 0.12 sec, p

• Balloon pulmonary angioplasty (BPA) significantly improved pulmonary arterial compliance (C PA) in inoperable CTEPH patients. • The changes of C PA were significantly correlated with improvement of 6-min walk distance (6MWD) in inoperable CTEPH patients with mPAP < 30 mmHg. • C PA can be a useful index in symptomatic CTEPH patients who have lower mPAP. Balloon pulmonary angioplasty (BPA) improved pulmonary arterial compliance (C PA) and exercise tolerance in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). To investigate whether C PA is a useful index to indicate exercise tolerance improvement by BPA in CTEPH patients. The correlation between changes in C PA and improvements in 6-minute walk distance (6MWD) by BPA was retrospectively analyzed in 70 patients (Analysis 1), and it was sequentially analyzed in 46 symptomatic patients who achieved mean pulmonary arterial pressure (mPAP)<30mmHg (Analysis 2). We enrolled 70 patients (female/male:57/13, mean age:59 years) who underwent a total of 352 BPA sessions which significantly increased C PA (1.5±0.8 vs. 3.0±1.0 mL/mmHg) and decreased pulmonary vascular resistance (PVR) (8.0 ± 3.9 vs. 3.6 ± 1.7 wood units). The correlation coefficient between improvement in 6MWD and changes in PVR and C PA were r=0.21 (p=0.09) and r=0.14 (p=0.26) (Analysis 1). In Analysis 2, those were r=0.32 (p=0.06) and r=0.38 (p=0.02), respectively. C PA can be a useful index to indicate the improvement in exercise tolerance by BPA in symptomatic patients with lower mPAP. [ABSTRACT FROM AUTHOR]

BackgroundPulmonary hypertension (PH) is an established risk factor in patients with heart failure (HF). However, right heart catheterisation (RHC) and vasoreactivity testing (VRT) are not routinely recommended in these patients.MethodsThe primary objective of the present study was to explore the impact of VRT using sublingual glyceryl trinitrate (GTN) on transplant/ventricular assist device-free survival in HF patients with post-capillary PH. RHC parameters were correlated retrospectively with the primary outcome.ResultsThe cohort comprised 154 HF patients with post-capillary PH undergoing RHC with GTN-VRT at a tertiary heart failure centre. Multiple parameters were associated with survival. After adjustment for established prognosis-relevant clinical variables from the MAGGIC Score, variables with the most relevant odds ratios (OR) obtained after GTN-VRT were: calculated effective pulmonary arterial (PA) elastance (adjusted OR 2.26, 95%CI 1.30–3.92; p = 0.004), PA compliance (PAC-GTN; adjusted OR 0.45, 95%CI 0.25–0.80; p = 0.006), and total pulmonary resistance (adjusted OR 2.29, 95%CI 1.34–3.93; p = 0.003). Forest plot analysis including these three variables as well as PAC at baseline, delta PAC, and the presence of combined post- and pre-capillary PH revealed prognostic superiority of PAC-GTN, which was confirmed by Kaplan-Meier analysis.ConclusionsIn our cohort of symptomatic HF patients with post-capillary PH, improved PAC after administration of GTN was associated with survival independent of established hemodynamic and clinical risk factors. VRT using GTN may be better described as unloading test due to GTN's complex effects on the circulation. This could be used for advanced prognostication and should be investigated in further studies.

Pulmonary hypertension (PH) is a common and prognostically important complication of mitral regurgitation (MR). Mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) are traditionally used to diagnose PH, however these indices measure static rather than pulsatile load, leading to an incomplete representation of pulmonary vascular load on the right ventricle (RV). Pulmonary arterial compliance (PAC) is one method for quantifying pulsatile load, and is both a stronger predictor of prognosis in left heart failure, as well as a more sensitive measure of early pulmonary vascular dysfunction than PVR. With the expansion of transcatheter mitral and tricuspid valve therapies, there is renewed interest to more accurately define the load imposed by the pulmonary vasculature on the RV, especially in the early phase, prior to the onset of chronic PH. This review discusses the pathophysiology of pH in left heart failure and MR, the utility of PAC as a measure of RV afterload, and its calculation for clinical use and interpretation, underlining the utility of PAC as an adjunct for assessing pulmonary vascular haemodynamics., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2024 Published by Elsevier B.V.)

Background: Pulmonary arterial compliance (PAC) is a prognostic parameter in pulmonary arterial hypertension (PAH) reflecting the elasticity of the pulmonary vessels. Objectives: The objective of this post hoc analysis of a prospective randomized controlled trial (RCT) was to assess the effect of exercise training on PAC and stroke volume (SV) in patients with PAH and persistent/inoperable chronic thromboembolic pulmonary hypertension (CTEPH). Method: From the previous RCT, 43 out of 87 patients with severe PAH (n = 29) and CTEPH (n = 14) had complete haemodynamic examinations at baseline and after 15 weeks by right heart catheterization and were analysed (53% female, 79% World Health Organization functional class III/IV, 58% combination therapy, 42% on supplemental oxygen therapy, training group n = 24, and control group n = 19). Medication remained unchanged for all patients. Results: Low-dose exercise training at 4–7 days/week significantly improved PAC (training group 0.33 ± 0.65 mL/mm Hg vs. control group −0.06 ± 1.10 mL/mm Hg; mean difference 0.39 mL/mm Hg, 95% confidence interval [CI] 0.15–0.94 mL/mm Hg; p = 0.004) and SV (training group 9.9 ± 13.4 mL/min vs. control group −4.2 ± 11.0 mL/min; mean difference 14.2 mL, 95% CI 6.5–21.8 mL; p < 0.001) in the training versus control group. Furthermore, exercise training significantly improved cardiac output and pulmonary vascular resistance at rest, peak oxygen consumption, and oxygen pulse. Conclusions: Our findings suggest that supervised exercise training may improve right ventricular function and PAC at the same time. Further prospective studies are needed to evaluate these findings. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

• The prognostic value of hemodynamics and comorbidities in pulmonary hypertension due to advanced heart failure was explored. • Pulmonary arterial compliance was a significant predictor for outcomes. • Patients burdened with more than 3 comorbidities had worse prognosis. • Obesity and hyperuricemia might be protective predictors for outcomes. The prognostic predictors of pulmonary hypertension (PH) due to advanced heart failure (HF) have yet to be explored. To examine the prognostic value of hemodynamics and comorbidities in this patient group. We retrospectively enrolled consecutive patients with PH due to advanced HF diagnosed by echocardiography and right heart catheterization. Follow-up was performed every 6 months ± 2 weeks. Primary endpoints were all-cause mortality and heart or lung transplantation. In total, 92 patients were included. The mean age was 46.82 years and mean left ventricular ejection fraction (LVEF) was 26.63%. During a median follow-up time of 9.72 months, 66 patients (71.7%) met primary endpoints. Pulmonary arterial compliance (PAC) was a significant predictor for primary endpoints and patients burdened with more than 3 comorbidities had worse prognoses (P = 0.0114). In these patients, PAC can be a potential prognostic predictor and patients with a higher comorbidity burden have worse outcomes. [ABSTRACT FROM AUTHOR]

Introduction: Pulmonary arterial compliance, the dynamic component of pulmonary vasculature, remains inadequately studied in patients with left to right shunts. We sought to study the pulmonary arterial compliance in patients with left to right shunt lesions and its utility in clinical decision-making., Materials and Methods: In this single-centre retrospective study, we reviewed cardiac catheterisation data of consecutive patients of left to right shunt lesions catheterised over one year. In addition to the various other parameters, pulmonary arterial compliance was calculated, as indexed pulmonary flow (Qpi) / (Heart rate × pulse pressure in the pulmonary artery). RC time was also calculated, as the product of pulmonary arterial compliance and pulmonary vascular resistance index. Patients were divided into "operable," "borderline," and "inoperable" based on the decision of the treating team, and the pulmonary arterial compliance values were evaluated in these groups to study if it can be utilised to refine the operability decision., Results: 298 patients (Median age 16 years, 56% <18 years) with various acyanotic shunt lesions were included. Overall, the pulmonary arterial compliance varied with Qpi, pulmonary artery mean pressure, and pulmonary vascular resistance index, but did not vary with age, type of lesion, or transpulmonary gradients. The median pulmonary arterial compliance in patients with normal pulmonary artery pressure (Mean pulmonary artery pressure less than 20 mmHg) was 4.1 ml/mmHg/m 2 (IQR 3.2). The median pulmonary arterial compliance for operable patients was 2.67 ml/mmHg/m 2 (IQR 2.2). Median pulmonary arterial compliance was significantly lower in both inoperable (0.52 ml/mmHg/m 2 , IQR 0.34) and borderline (0.80 ml/mmHg/m 2 , IQR 0.36) groups when compared to operable patients (p < 0.001). A pulmonary arterial compliance value lower than 1.18 ml/mmHg/m 2 identified inoperable patients with high sensitivity and specificity (95%, AUC 0.99). However, in borderline cases, assessment by this value did not agree with empirical clinical assessment.The median RC time for the entire study population was 0.47 S (IQR 0.30). RC time in operable patients was significantly lower than that in the inoperable patients (Median 0.40 IQR 0.23 in operable, 0.73 0.25 in inoperable patients (p < 0.001)., Conclusions: Addition of pulmonary arterial compliance to the routine haemodynamic assessment of patients with shunt lesions may improve our understanding of the pulmonary circulation and may have clinical utility.

Abstract Aims Although pulmonary arterial remolding in pulmonary hypertension (PH) changes the mechanical properties of the pulmonary artery, most clinical studies have focused on static mechanical properties (resistance), and dynamic mechanical properties (compliance) have not attracted much attention. As arterial compliance plays a significant role in determining afterload of the right ventricle, we evaluated how PH changes the dynamic mechanical properties of the pulmonary artery using high-resolution, wideband input impedance (Z PA). We then examined how changes in Z PA account for arterial remodeling. Clarification of the relationship between arterial remodeling and Z PA could help evaluate arterial remodeling according to hemodynamics. Main methods PH was induced in Sprague–Dawley rats with an injection of Sugen5416 (20 mg/kg) and 3-week exposure to hypoxia (10% oxygen) (SuHx). Z PA was evaluated from pulmonary artery pressure and flow under irregular pacing. Pulmonary histology was examined at baseline and 1, 3, and 8 weeks (n = 7, each) after Sugen5416 injection. Key findings SuHx progressively increased pulmonary arterial pressure. Z PA findings indicated that SuHx progressively increased resistance (baseline: 9.3 ± 3.6, SuHx1W: 20.7 ± 7.9, SuHx3W: 48.8 ± 6.9, SuHx8W: 62.9 ± 17.8 mm Hg/mL/s, p < 0.01) and decreased compliance (baseline: 11.9 ± 2.1, SuHx1W: 5.3 ± 1.7, SuHx3W: 2.1 ± 0.7, SuHx8W: 1.9 ± 0.6 × 10−3 mL/mm Hg, p < 0.01). The time constant did not significantly change. The progressive reduction in compliance was closely associated with wall thickening of small pulmonary arteries. Significance The finding that changes in resistance were reciprocally associated with those in compliance indicates that resistant and compliant vessels are anatomically inseparable. The analysis of Z PA might help evaluate arterial remodeling in PH according to hemodynamics. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Objectives: Pulmonary vascular dysfunction is associated with adverse prognosis in patients with the acute respiratory distress syndrome; however, the prognostic impact of pulmonary arterial compliance in acute respiratory distress syndrome is not established.Design, Setting, Patients: We performed a retrospective analysis of 363 subjects with acute respiratory distress syndrome who had complete baseline right heart catheterization data from the Fluid and Catheter Treatment Trial to test whether pulmonary arterial compliance at baseline and over the course of treatment predicted mortality.Main Results: Baseline pulmonary arterial compliance (hazard ratio, 1.18 per interquartile range of 1/pulmonary arterial compliance; 95% CI, 1.02-1.37; p = 0.03) and pulmonary vascular resistance (hazard ratio, 1.28 per interquartile range; 95% CI, 1.07-1.53; p = 0.006) both modestly predicted 60-day mortality. Baseline pulmonary arterial compliance remained predictive of mortality when pulmonary vascular resistance was in the normal range (p = 0.02). Between day 0 and day 3, pulmonary arterial compliance increased in acute respiratory distress syndrome survivors and remained unchanged in nonsurvivors, whereas pulmonary vascular resistance did not change in either group. The resistance-compliance product (resistance-compliance time) increased in survivors compared with nonsurvivors, suggesting improvements in right ventricular load.Conclusions: Baseline measures of pulmonary arterial compliance and pulmonary vascular resistance predict mortality in acute respiratory distress syndrome, and pulmonary arterial compliance remains predictive even when pulmonary vascular resistance is normal. Pulmonary arterial compliance and right ventricular load improve over time in acute respiratory distress syndrome survivors. Future studies should assess the impact of right ventricular protective acute respiratory distress syndrome treatment on right ventricular afterload and outcome. [ABSTRACT FROM AUTHOR]

Background Right ventricular (RV) adaptation to afterload is crucial for patients undergoing continuous-flow left ventricular assist device (cf-LVAD) implantation. We hypothesized that stratifying patients by RV pulsatile load, using pulmonary arterial compliance (PAC), and RV response to load, using the ratio of central venous to pulmonary capillary wedge pressure (CVP:PCWP), would identify patients at high risk for early right heart failure (RHF) and 6-month mortality after cf-LVAD. Methods During the period from January 2008 to June 2014, we identified 151 patients at our center with complete hemodynamics prior to cf-LVAD. Pulsatile load was estimated using PAC indexed to body surface area (BSA), according to the formula: indexed PAC (PACi) = [SV / (PA systolic – PA diastolic )] / BSA, where SV is stroke volume and PA is pulmonary artery. Patients were divided into 4 hemodynamic groups by PACi and CVP:PCWP. RHF was defined as the need for unplanned RVAD, inotropic support ≥14 days or death due to RHF within 14 days. Risk factors for RHF and 6-month mortality were examined using logistic regression and Cox proportional hazards modeling. Results Sixty-one patients (40.4%) developed RHF and 34 patients (22.5%) died within 6 months. Patients with RHF had lower PACi (0.92 vs 1.17 ml/mm Hg/m 2 , p = 0.008) and higher CVP:PCWP (0.48 vs 0.37, p = 0.001). Higher PACi was associated with reduced risk of RHF (adjusted odds ratio [adj-OR] 0.61, 95% confidence interval [CI] 0.39 to 0.94, p = 0.025) and low PACi with increased risk of 6-month mortality (adjusted hazard ratio [adj-HR] 3.18, 95% CI 1.40 to 7.25, p = 0.006). Compared to patients with low load (high PACi) and adequate right heart response to load (low CVP:PCWP), patients with low PACi and high CVP:PCWP had an increased risk of RHF (OR 4.74, 95% CI 1.23 to 18.24, p = 0.02) and 6-month mortality (HR 8.68, 95% CI 2.79 to 26.99, p < 0.001). Conclusions A hemodynamic profile combining RV pulsatile load and response to load identifies patients at high risk for RHF and 6-month mortality after cf-LVAD. [ABSTRACT FROM AUTHOR]

Background: We hypothesized that longitudinal pulmonary arterial deformation during the cardiac cycle reflects pulmonary arterial capacitance. To examine this hypothesis, we assessed whether tissue Doppler-derived pulmonary annular motion could serve as a novel way to evaluate pulmonary arterial capacitance in pediatric patients with ventricular septal defect (VSD).Methods: In this prospective study, pulmonary annular velocity was measured in children (age, 6 months-5 years) with a preoperative VSD (VSD group, n = 35) and age-matched healthy children (Control group, n = 23). Pulmonary artery capacitance was calculated by two methods. Systolic pulmonary arterial capacitance (sPAC) was expressed as the stroke volume/pulmonary arterial pulse pressure. Diastolic pulmonary arterial capacitance (dPAC) was determined according to a two-element windkessel model of the pulmonary arterial diastolic pressure profile.Results: Pulmonary annular velocity waveforms comprised systolic bimodal (s1' and s2') and diastolic e' and a' waves in all participants. The peak velocities of s1', s2', and e' were significantly lower in the VSD group than in the Control group. On multiple regression analysis, sPAC was an independent variable affecting the peak velocities of the s1', s2', and e' waves (β = 0.41, 0.62, and 0.35, respectively). The dPAC affected the s1' wave peak velocity (β = 0.34). The time durations of the s1' and e' waves were independently determined by the sPAC (β = 0.49 and 0.27).Conclusion: Pulmonary annular motion velocity evaluated using tissue Doppler is a promising method of assessing pulmonary arterial capacitance in children with VSD. [ABSTRACT FROM AUTHOR]

Pulmonary hypertension associated with left heart disease is the most common form of pulmonary hypertension. Although its pathophysiology remains incompletely understood, it is now well recognized that the presence of pulmonary hypertension is associated with a worse prognosis. Right ventricular failure has independent and additive prognostic value over pulmonary hypertension for adverse outcomes in left heart disease. Recently, several new terminologies have been introduced to better define and characterize the nature and severity of pulmonary hypertension. Several new treatment options including the use of pulmonary arterial hypertension specific therapies are being considered, but there is lack of evidence. Here, we review the recent advances in this field and summarize the diagnostic and therapeutic modalities of use in the management of pulmonary hypertension associated with left heart disease. [ABSTRACT FROM AUTHOR]

Background Pulmonary hypertension (PH) is often found in cystic fibrosis (CF) patients affected by end-stage lung disease but its impact on outcome remains unclear. Pulmonary arterial compliance (PAC) is an important determinant of right ventricle (RV) workload and it is a strong predictor of survival in other forms of PH. The aim of this study is to investigate whether PAC is a predictor of long-term prognosis in a population of CF patients affected by advanced lung disease. Methods Between 2000 and 2014, 178 patients with CF have been evaluated for lung transplantation in our CF Center. Right heart catheterization (RHC) and follow up data were retrievable and analyzed in 141 of them. PAC was defined as the ratio between stroke volume (SV) and pulse pressure (PP) at heart catheterization. The association of PAC with survival was tested at 4 years and compared to other hemodynamic parameters. Results PH prevalence was 56.4%. Most patients had mild elevation of pulmonary artery pressure (PAP). No difference in mortality was observed in patients with PH compared to patients with normal PAP (HR 0.95: 95% CI 0.49–1.89, p = 0.89). At receiver operating characteristic curve (ROC) analysis, the optimal prognostic cut-off point of PAC was 1.95 ml/mmHg. An impaired PAC (≤ 1.95 ml/mmHg) was a strong independent predictor of long-term mortality (HR 3.44: 95% CI 1.51–7.85: p = 0.003). Conclusions Impaired PAC is associated with poor prognosis in CF patients awaiting lung transplantation. Other traditional hemodynamic parameters add no prognostic information. [ABSTRACT FROM AUTHOR]

Pulmonary hypertension associated with congenital heart disease (CHD-PH) encompasses different conditions confounded by the left-to-right shunt, left heart obstruction, ventricular dysfunction, hypoxia due to airway obstruction, dysplasia/hypoplasia of the pulmonary vasculature, pulmonary vascular obstructive disease, and genetic variations of vasoactive mediators. Pulmonary input impedance consists of the pulmonary vascular resistance (Rp) and capacitance (Cp). Rp is calculated as the transpulmonary pressure divided by the pulmonary cardiac output, whereas Cp is calculated as the pulmonary stroke volume divided by the pulmonary arterial pulse pressure. The plots of Rp and Cp demonstrate a unique hyperbolic relationship, namely, the resistor-capacitor coupling curve, which represents the pulmonary vascular condition. The product of Rp and Cp is the exponential pressure decay, which refers to the time constant. Alterations in Cp are more considerable in CHD patients at an early stage of developing pulmonary hypertension or with excessive pulmonary blood flow due to a left-to-right shunt. The importance of Cp has gained attention because recent reports have shown that low Cp potentially reflects poor prognosis in patients with CHD-PH and idiopathic pulmonary hypertension. It is also known that Cp levels decrease in specific populations, such as preterm infants and trisomy 21. Therefore, both Rp and Cp should be individually evaluated in the management of children with CHD-PH who have different disease conditions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2022 Muneuchi, Ezaki, Sugitani and Watanabe.)

Abstract: Awareness has grown in recent years that right ventricular (RV) function is equally important as left ventricular (LV) function in the setting of left-sided heart disease. RV dysfunction can be the consequence of an increased afterload imposed by the failing LV. The concept of “afterload” is physically most correctly described by vascular input impedance. However, for clinical purposes, afterload is most often modeled to consist of 3 components; pulmonary vascular resistance (PVR), pulmonary arterial compliance (PAC), and characteristic impedance. Whereas PVR is historically most described, PAC (which represents the distensibility of the vasculature) has rapidly gained recognition for its prognostic ability in both pulmonary arterial hypertension and left-sided heart disease. Owing to the specific anatomy of the pulmonary circulation, PVR and PAC have an inverse hyperbolic relationship, which position can be shifted by varying wedge pressures. Knowledge of the afterload components helps one to understand how elevated left-sided filling pressures increase pulsatile load on the RV. An increase in resistive load (known as “reactive” or “out-of-proportion” pulmonary hypertension) ultimately complements the increase in pulsatile load. Perturbations in nitric oxide metabolism are thought to be crucial in this evolution and have therefore been sought as a major therapeutic target. [Copyright &y& Elsevier]

The time constant of the pulmonary circulation, or product of pulmonary vascular resistance (PVR) and compliance (Ca), called the RC-time, has been reported to remain constant over a wide range of pressures, etiologies of pulmonary hypertension, and treatments. We wondered if increased wave reflection on proximal pulmonary vascular obstruction, like in operable chronic thromboembolic pulmonary hypertension, might also decrease the RC-time and thereby increase pulse pressure and right ventricular afterload. Pulmonary hypertension of variable severity was induced either by proximal obstruction (pulmonary arterial ensnarement) or distal obstruction (microembolism) eight anesthetized dogs. Pulmonary arterial pressures (Ppa) were measured with high-fidelity micromanometer-tipped catheters, and pulmonary flow with transonic technology. Pulmonary ensnarement increased mean Ppa, PVR, and characteristic impedance, decreased Ca and the RC-time (from 0.46 ± 0.07 to 0.30 ± 0.03 s), and increased the oscillatory component of hydraulic load (Wosc/Wtot) from 25 ± 2 to 29 ± 2%. Pulmonary microembolism increased mean Ppa and PVR, with no significant change in Ca and characteristic impedance, increased RC-time from 0.53 ± 0.09 to 0.74 ± 0.05 s, and decreased Wosc/Wtot from 26 ± 2 to 13 ± 2%. Pulse pressure increased more after pulmonary ensnarement than after microembolism. Concomitant measurements with fluid-filled catheters showed the same functional differences between the two types of pulmonary hypertension, with, however, an underestimation of Wosc. We conclude that pulmonary hypertension caused by proximal vs. distal obstruction is associated with a decreased RC-time and increased pulsatile component of right ventricular hydraulic load. [ABSTRACT FROM AUTHOR]

Previous studies have documented the normal values of pulmonary arterial compliance (Cp) in animals and adult humans. In the past, variations in Cp and its measurement in children with septal defects has been unknown. In the present study, we found the Windkessel model, which uses compliance and resistance as parameters, to be a useful tool in understanding Cp in pediatric patients. Calculations of Cp were based on the pulmonary arterial diastolic pressure waveform as an exponential function of time. First, Cp was estimated by studying pressure tracings of the main pulmonary artery (MPA) obtained from both routine cardiac catheterization and pressure measured by a catheter-tip manometer, which was performed during a catheterization study of seven children with various congenital heart diseases. Second, 124 children with atrial and ventricular septal defects aged between 45 days and 12 years were studied using the data obtained from routine catheterization. Hemodynamic data were used to calculate pulmonary vascular resistance (Rp), pulmonary arterial time constant (Tp) and Cp. A strong correlation ( r = 0.954) was found in the Cp value estimated by data obtained from routine catheterization and from the catheter-tip manometer study. The present study shows an estimated mean (SEM) Cp in normal children of 1.53 (0.17) ml/mmHg per m2. The estimated mean (SEM) Cp was 1.91 (0.10) and 1.70 (0.11) ml/mmHg per m2 in children with atrial septal defect (ASD) and ventricular septal defect (VSD), respectively. It was found that Cp was significantly ( P = 0.04) higher in female patients with a VSD. Also, a significantly low Cp (0.95 ± 0.06 ml/mmHg per m2) was observed in patients with a VSD and pulmonary hypertension (VSDPH). In conclusion, Cp was calculated by the exponential decay portion of the MPA diastolic pressure waveform. A normal Cp value was observed in ASD and VSD patients and a significantly low Cp was observed in children with a VSDPH. Cp was higher in female VSD patients than in male VSD patients. [ABSTRACT FROM AUTHOR]

Background: Chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary arterial hypertension (PAH) are characterized by elevated pulmonary arterial pressure resulting in right heart failure. Right ventricular (RV) dyssynchrony may be associated with early-stage RV dysfunction; however, the differences in RV dyssynchrony between CTEPH and PAH and the factors contributing to RV dyssynchrony remain unclear., Methods and results: Forty-four patients (CTEPH, 26; PAH, 18) were enrolled in this study. RV dyssynchrony was assessed by determining the standard deviation of the intervals from the peak QRS to peak systolic strain for 6 segments of the RV free and septal wall by using 2-dimensional speckle-tracking echocardiography (RV-6SD). The RV-6SD, pulmonary hemodynamics, echocardiographic findings, and patient demographics in CTEPH and PAH patients were compared and their correlations with RV-6SD were investigated. CTEPH patients were older and had significantly higher pulse pressure of the pulmonary artery (PP), tricuspid valve regurgitation pressure gradient, and RV-6SD, and lower pulmonary arterial compliance (PAC), despite showing comparable pulmonary arterial pressures. Age-adjusted multiple logistic analysis showed that RV-6SD and PAC were predictors of CTEPH rather than PAH. RV-SD6 was positively correlated with PP and RV dimension and negatively correlated with PAC., Conclusions: CTEPH patients showed more evident RV dyssynchrony than PAH patients. Low PAC and a widened PP may delay RV free wall motion and cause RV dyssynchrony.

Background: Pulmonary hypertension (PH) is an established risk factor in patients with heart failure (HF). However, right heart catheterisation (RHC) and vasoreactivity testing (VRT) are not routinely recommended in these patients., Methods: The primary objective of the present study was to explore the impact of VRT using sublingual glyceryl trinitrate (GTN) on transplant/ventricular assist device-free survival in HF patients with post-capillary PH. RHC parameters were correlated retrospectively with the primary outcome., Results: The cohort comprised 154 HF patients with post-capillary PH undergoing RHC with GTN-VRT at a tertiary heart failure centre. Multiple parameters were associated with survival. After adjustment for established prognosis-relevant clinical variables from the MAGGIC Score, variables with the most relevant odds ratios (OR) obtained after GTN-VRT were: calculated effective pulmonary arterial (PA) elastance (adjusted OR 2.26, 95%CI 1.30-3.92; p = 0.004), PA compliance (PAC-GTN; adjusted OR 0.45, 95%CI 0.25-0.80; p = 0.006), and total pulmonary resistance (adjusted OR 2.29, 95%CI 1.34-3.93; p = 0.003). Forest plot analysis including these three variables as well as PAC at baseline, delta PAC, and the presence of combined post- and pre-capillary PH revealed prognostic superiority of PAC-GTN, which was confirmed by Kaplan-Meier analysis., Conclusions: In our cohort of symptomatic HF patients with post-capillary PH, improved PAC after administration of GTN was associated with survival independent of established hemodynamic and clinical risk factors. VRT using GTN may be better described as unloading test due to GTN's complex effects on the circulation. This could be used for advanced prognostication and should be investigated in further studies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Rieth, Grün, Zarogiannis, Kriechbaum, Wolter, Richter, Tello, Krüger, Mitrovic, Rosenkranz, Hamm and Keller.)

Heart failure (HF) is an ongoing crisis reaching epidemic proportions worldwide. About 50% of HF patients have a preserved ejection fraction. Invasive hemodynamics have shown varied results in patients who have HF with preserved ejection fraction (HFpEF). This article attempts to summarize the importance of detecting pulmonary vascular remodeling in HFpEF using invasive hemodynamics. Incorporating newer invasive hemodynamic parameters such as diastolic pulmonary gradient, pulmonary arterial compliance, pulmonary vascular resistance, and pulmonary arterial pulsatility index may improve patient selection for studies used in defining advanced therapies and clinical outcomes. Profiling of patients using invasive hemodynamic parameters may lead to better patient selection for clinical research., Competing Interests: Disclosure Dr N. Nair has no disclosures with relevance to this work., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Combined pulmonary fibrosis and emphysema (CPFE) is a common but under-recognized syndrome characterized with distinct profiles of both pulmonary fibrosis and emphysema. Pulmonary hypertension (PH) is particularly prone to develop as a common complication, leading to exercise limitation and worse prognosis of CPFE. Although the therapy of patients with PH from CPFE cannot be endorsed, an individual treatment may be considerable when accompanying severe PH. We report a case of a 71-year-old male with PH from CPFE, who improved pulmonary arterial compliance (PAC) and exercise capacity in response to pulmonary vasodilator. [ABSTRACT FROM AUTHOR]

Pulmonary arterial compliance (PAC), invasively assessed by the ratio of stroke volume to pulmonary arterial (PA) pulse pressure, is a sensitive marker of right ventricular (RV)-PA coupling that differs across the spectrum of pulmonary hypertension (PH) and is predictive of outcomes. We assessed whether the echocardiographically derived ratio of RV outflow tract velocity time integral to PA systolic pressure (RVOT-VTI/PASP) (a) correlates with invasive PAC, (b) discriminates heart failure with preserved ejection-associated PH (HFpEF-PH) from pulmonary arterial hypertension (PAH), and (c) is associated with functional capacity. We performed a retrospective cohort study of patients with PAH (n = 70) and HFpEF-PH (n = 86), which was further dichotomized by diastolic pressure gradient (DPG) into isolated post-capillary PH (DPG < 7 mmHg; Ipc-PH, n = 54), and combined post- and pre-capillary PH (DPG ≥ 7 mm Hg; Cpc-PH, n = 32). Of the 156 patients, 146 had measurable RVOT-VTI or PASP and were included in further analysis. RVOT-VTI/PASP correlated with invasive PAC overall (ρ = 0.61, P < 0.001) and for the PAH (ρ = 0.38, P = 0.002) and HFpEF-PH (ρ = 0.63, P < 0.001) groups individually. RVOT-VTI/PASP differed significantly across the PH spectrum (PAH: 0.13 [0.010-0.25] vs. Cpc-PH: 0.20 [0.12-0.25] vs. Ipc-PH: 0.35 [0.22-0.44]; P < 0.001), distinguished HFpEF-PH from PAH (AUC = 0.72, 95% CI = 0.63-0.81) and Cpc-PH from Ipc-PH (AUC = 0.78, 95% CI = 0.68-0.88), and remained independently predictive of 6-min walk distance after multivariate analysis (standardized β-coefficient = 27.7, 95% CI = 9.2-46.3; P = 0.004). Echocardiographic RVOT-VTI/PASP is a novel non-invasive metric of PAC that differs across the spectrum of PH. It distinguishes the degree of pre-capillary disease within HFpEF-PH and is predictive of functional capacity.

Background: We hypothesized that longitudinal pulmonary arterial deformation during the cardiac cycle reflects pulmonary arterial capacitance. To examine this hypothesis, we assessed whether tissue Doppler-derived pulmonary annular motion could serve as a novel way to evaluate pulmonary arterial capacitance in pediatric patients with ventricular septal defect (VSD)., Methods: In this prospective study, pulmonary annular velocity was measured in children (age, 6 months-5 years) with a preoperative VSD (VSD group, n = 35) and age-matched healthy children (Control group, n = 23). Pulmonary artery capacitance was calculated by two methods. Systolic pulmonary arterial capacitance (sPAC) was expressed as the stroke volume/pulmonary arterial pulse pressure. Diastolic pulmonary arterial capacitance (dPAC) was determined according to a two-element windkessel model of the pulmonary arterial diastolic pressure profile., Results: Pulmonary annular velocity waveforms comprised systolic bimodal (s1' and s2') and diastolic e' and a' waves in all participants. The peak velocities of s1', s2', and e' were significantly lower in the VSD group than in the Control group. On multiple regression analysis, sPAC was an independent variable affecting the peak velocities of the s1', s2', and e' waves (β = 0.41, 0.62, and 0.35, respectively). The dPAC affected the s1' wave peak velocity (β = 0.34). The time durations of the s1' and e' waves were independently determined by the sPAC (β = 0.49 and 0.27)., Conclusion: Pulmonary annular motion velocity evaluated using tissue Doppler is a promising method of assessing pulmonary arterial capacitance in children with VSD.

The pulmonary circulation is a high-flow/low-pressure system, coupled with a flow generator chamber-the right ventricle-, which is relatively unable to tolerate increases in afterload. A right heart catheterization, using a fluid-filled, balloon-tipped Swan-Ganz catheter allows the measurement of all hemodynamic parameters characterizing the pulmonary circulation: the inflow pressure, an acceptable estimate the outflow pressure, and the pulmonary blood flow. However, the study of the pulmonary circulation as a continuous flow system is an oversimplification and a thorough evaluation of the pulmonary circulation requires a correct understanding of the load that the pulmonary vascular bed imposes on the right ventricle, which includes static and dynamic components. This is critical to assess the prognosis of patients with pulmonary hypertension or with heart failure. Pulmonary compliance is a measure of arterial distensibility and, either alone or in combination with pulmonary vascular resistance, gives clinicians the possibility of a good prognostic stratification of patients with heart failure or with pulmonary hypertension. The measurement of pulmonary arterial compliance should be included in the routine clinical evaluation of such patients.

Background: Patients with normalized mean pulmonary artery pressure (mPAP) after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) do not always regain normal exercise capacity. We evaluated right ventricular function, its interaction with both pulsatile and resistive afterload, and the effect of sildenafil during exercise in these patients., Methods and Results: Fourteen healthy controls, 15 CTEPH patients, and 7 patients with normalized resting mPAP (≤25 mm Hg) post-PEA underwent cardiopulmonary exercise testing, followed by cardiac magnetic resonance imaging with simultaneous invasive mPAP measurement during incremental supine cycling exercise. Peak oxygen consumption and peak heart rate were significantly reduced in post-PEA and CTEPH patients compared to controls. The mPAP-cardiac output slope was steeper in post-PEA patients than in controls and similar to CTEPH. Relative to controls, resting right ventricular ejection fraction was reduced in CTEPH, but not in post-PEA patients. In contrast, peak exercise right ventricular ejection fraction was reduced both in post-PEA and CTEPH patients. Exercise led to reduction of pulmonary arterial compliance in all groups. Nevertheless, resting pulmonary arterial compliance values in CTEPH and post-PEA patients were even lower than those in controls at peak exercise. In post-PEA patients, sildenafil did not affect resting hemodynamics nor right ventricular function, but decreased the mPAP/cardiac output slope and increased peak exercise right ventricular ejection fraction., Conclusions: Exercise intolerance in post-PEA patients is explained by abnormal pulmonary vascular reserve and chronotropic incompetence. The mPAP/cardiac output slope and pulmonary arterial compliance are sensitive measures demonstrating abnormal resistive and pulsatile pulmonary vascular function in post-PEA patients. These abnormalities are partially attenuated with sildenafil., (© 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Survival in patients with pulmonary arterial hypertension (PAH) is closely related to right ventricular (RV) function. Although pulmonary load is an important determinant of RV systolic function in PAH, there remains a significant variability in RV adaptation to pulmonary hypertension. In this report, the authors discuss the emerging concepts of right heart pathobiology in PAH. More specifically, the discussion focuses on the following questions. 1) How is right heart failure syndrome best defined? 2) What are the underlying molecular mechanisms of the failing right ventricle in PAH? 3) How are RV contractility and function and their prognostic implications best assessed? 4) What is the role of targeted RV therapy? Throughout the report, the authors highlight differences between right and left heart failure and outline key areas of future investigation., (Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)