Pulmonary Artery Distensibility Research Articles

Association between Thoracic Radiographic Changes and Indicators of Pulmonary Hypertension in Dogs with Heartworm Disease.

Pulmonary hypertension (PH) is a consequence of pulmonary endarteritis during infection with Dirofilaria immitis in dogs. Echocardiography is the technique of choice but is not always accessible to all clinicians. This study aimed to evaluate the association of the radiological findings in dogs with heartworm disease and the presence or absence of echocardiographically characterised PH. The study included 62 heartworm-infected dogs that underwent thoracic radiographs and echocardiography. The studied dogs showed moderate to severe PH when the Right Pulmonary Artery Distensibility (RPAD) Index was <29.5%. The RPAD Index was used for comparison with thoracic radiographs. The Vertebral Heart Size (VHS), right cranial pulmonary artery passing through the fourth rib in the laterolateral projection (CrPA/R4) ratio, and right caudal pulmonary artery to the ninth rib in the dorsoventral projection (CdPA/R9) ratio showed significant differences between dogs with/without PH (p < 0.001). Sensitivity (sen) and specificity (sp) cut-off values were obtained: VHS ≥ 9.53 (sen 93.75%, sp 63.33%); CrPA/R4 ≥ 1.08 (sen 87.5%, sp 70%); and CdPA/R9 ≥ 1.10 (sen 96.88%, sp 76.66%). The CrPA/R4 and CdPA/R9 ratios showed potential as a preliminary screening tool for PH in heartworm-infected dogs, suggesting that they may reliably indicate the presence of PH and guide the decision for further diagnostic testing.

Right main pulmonary artery distensibility on dynamic ventilation CT and its association with respiratory function

BackgroundHeartbeat-based cross-sectional area (CSA) changes in the right main pulmonary artery (MPA), which reflects its distensibility associated with pulmonary hypertension, can be measured using dynamic ventilation computed tomography (DVCT) in patients with and without chronic obstructive pulmonary disease (COPD) during respiratory dynamics. We investigated the relationship between MPA distensibility (MPAD) and respiratory function and how heartbeat-based CSA is related to spirometry, mean lung density (MLD), and patient characteristics.MethodsWe retrospectively analyzed DVCT performed preoperatively in 37 patients (20 female and 17 males) with lung cancer aged 70.6 ± 7.9 years (mean ± standard deviation), 18 with COPD and 19 without. MPA-CSA was separated into respiratory and heartbeat waves by discrete Fourier transformation. For the cardiac pulse-derived waves, CSA change (CSAC) and CSA change ratio (CSACR) were calculated separately during inhalation and exhalation. Spearman rank correlation was computed.ResultIn the group without COPD as well as all cases, CSACR exhalation was inversely correlated with percent residual lung volume (%RV) and RV/total lung capacity (r = -0.68, p = 0.003 and r = -0.58, p = 0.014). In contrast, in the group with COPD, CSAC inhalation was correlated with MLDmax and MLD change rate (MLDmax/MLDmin) (r = 0.54, p = 0.020 and r = 0.64, p = 0.004) as well as CSAC exhalation and CSACR exhalation.ConclusionIn patients with insufficient exhalation, right MPAD during exhalation was decreased. Also, in COPD patients with insufficient exhalation, right MPAD was reduced during inhalation as well as exhalation, which implied that exhalation impairment is a contributing factor to pulmonary hypertension complicated with COPD.Relevance statementAssessment of MPAD in different respiratory phases on DVCT has the potential to be utilized as a non-invasive assessment for pulmonary hypertension due to lung disease and/or hypoxia and elucidation of its pathogenesis.Key points• There are no previous studies analyzing all respiratory phases of right main pulmonary artery distensibility (MPAD).• Patients with exhalation impairment decreased their right MPAD.• Analysis of MPAD on dynamic ventilation computed tomography contributes to understanding the pathogenesis of pulmonary hypertension due to lung disease and/or hypoxia in patients with expiratory impairment.Graphical

Predictive Value of Pulmonary Artery Distensibility for Short-Term Adverse Clinical Outcomes in Patients with Acute Pulmonary Embolism.

We aimed to explore the relationship between pulmonary artery distensibility obtained from computed tomography pulmonary angiography (CTPA) and short-term adverse clinical outcomes in patients with acute pulmonary embolism (APE). We included patients who underwent retrospective electrocardiogram-gated CTPA and were subsequently diagnosed with APE. Patients were categorized into good and poor outcome groups based on short-term clinical outcomes. Pulmonary artery distensibility (AD), right ventricle/left ventricle (RV/LV) ratio, and pulmonary artery obstruction index (PAOI) were measured, and the receiver operating characteristic curves were constructed. Sixty-four patients with APE (good outcome, 46; poor outcome, 18) were enrolled. AD, RV/LV ratio, and PAOI differed significantly between groups (P < 0.05). Pulmonary artery AD in the good outcome group was greater than that in the poor outcome group (P < 0.001). The poor outcome group exhibited a higher RV/LV ratio and PAOI than the good outcome group (P < 0.05). AD and PAOI were independent predictors of adverse clinical outcomes. Areas under the curve for AD and PAOI were 0.860 (95% confidence interval [CI]: 0.750-0.934) and 0.675 (95%CI: 0.546-0.786), and the combined curve of the AD and RV/LV ratio was 0.906 (95%CI: 0.806-0.965). The calibration curve showed a combined curve superior to the other curves. The decision curve showed high clinical application value of the combined curve. Retrospective electrocardiogram-gated CTPA-derived AD could serve as an indicator for predicting short-term adverse clinical outcomes in APE. Combining AD and PAOI has a high predictive value for short-term adverse clinical outcomes.

Right Ventricle Strain Assessed by 2-Dimensional Speckle Tracking Echocardiography (2D-STE) to Evaluate Pulmonary Hypertension in Dogs with Dirofilaria immitis.

Echocardiographic assessment of the right ventricle is helpful for analysing the pathophysiology of heartworm disease and detecting pulmonary hypertension (PH) in dogs. In veterinary cardiology, the study of myocardial deformation using two-dimensional speckle tracking (2D-STE) echocardiography has become increasingly acknowledged as useful for quantifying right ventricular function. The aim of this study was to evaluate the usefulness of myocardial deformation strain of the right ventricular free wall (FWS), global deformation strain of the right ventricle, including the interventricular septum (GS), and tissue motion annular displacement of the tricuspid valve (TMAD) in a cohort of dogs with heartworm (Dirofilaria immitis) disease and to determine cut-off values for detecting the presence of PH. Out of the 93 dogs tested, 71% were diagnosed with heartworm infection. PH was identified in 41% of the infected dogs following the American College of Veterinary Internal Medicine (ACVIM) guidelines, based on the peak tricuspid regurgitation velocity to calculate the tricuspid regurgitation pressure gradient (TRPG), while other routine measurements were used, including the right pulmonary artery distensibility index (RPADi). The 2D-STE mode measurements were determined using Right Ventricular Automated Function Imaging (RV AFI®) software. The statistical analysis showed significant differences in the studied parameters among dogs with and without PH. Additionally, sensitivity (sen) and specificity (sp) cut-off values were obtained (GS ≥ -21.25%, sen 96%, sp 86.4%; FWS ≥ -21.95%, sen 92.56%, sp 95.5%; TMAD ≤ 0.85 cm, sen 70.4%, sp 83.3%). These results demonstrated that GS, FWS, and TMAD could be used as supplementary and alternative variables to conventional echocardiographic measurements when detecting PH in dogs with heartworm disease.

Usefulness of Tissue Doppler Imaging for the Evaluation of Pulmonary Hypertension in Canine Heartworm Disease

Background: Dirofilaria immitis is a nematode that produces proliferative pulmonary endarteritis in dogs due to direct contact of the adult parasites with the intima layer of the pulmonary arteries, leading to irreversible severe structural damage and sustained pulmonary hypertension (PH), which can produce severe cardiorespiratory disorders. The purpose of this study was to assess the diagnostic value of the echocardiography tissue Doppler imaging (TDI) in determining the presence of PH in dogs with heartworm disease. Methods: There were 116 heartworm-infected dogs with PH and 33 healthy dogs included in the study. Based on the right pulmonary artery distensibility index (RPADi) &lt; 29.5%, PH was present in 47.4% of infected dogs. Additionally, the animals were evaluated using other standard alternative echocardiographic measures to estimate PH. Moreover, a total of eight echocardiographic measurements were analysed using the TDI to determine its usefulness in diagnosing PH (E′, A′, S, E′:A′, global TDI, HRI-IVCT, HRI-IVRT, R-TEI). Results: The TDI measurements showed significant differences between dogs with and without PH, demonstrating a positive correlation with respect to the RPADi. In addition, cut-off values for the detection of PH with excellent sensitivity and specificity were found for E′:A′, global TDI, HRI-IVCT, HRI-IVRT and R-TEI. Conclusions: The TDI mode may be useful as an adjunct diagnostic method for the determination of PH in dogs with Dirofilaria immitis.

Diagnostic value of two-dimensional echocardiographic measurements of the pulmonary artery diameter and the pulmonary artery distensibility index to detect pulmonary hypertension in horses

Introduction/objectivesEchocardiographic diagnosis of pulmonary hypertension (PH) in horses is usually based on Doppler interrogation of tricuspid (TR) or pulmonic regurgitation (PR). This study aimed at investigating two-dimensional echocardiographic (2DE) variables, including pulmonary artery diameter (PAD) and pulmonary artery distensibility index (PADI), to diagnose PH. Animals, materials and methods41 healthy horses; 82 horses with TR or PR and normal intracardiac pressure gradients; and 35 horses with TR or PR velocities indicating PH. The 2DE variables were compared between groups, cut-offs for the diagnosis of PH were determined, and conditional inference trees served to identify the variable best predicting PH in the absence of TR or PR. ResultsHorses with PH had larger end-diastolic cross-sectional (short-axis) PAD (PADed-sx) (5.8 ± 1.0 cm; mean ± SD) and smaller PADI[/PADps] (15.4 ± 7.7%) than healthy horses (5.0 ± 0.6 cm, P<0.0001; 20.5 ± 4.4%, P<0.001) and horses with TR or PR but no PH (5.3 ± 0.6 cm, P=0.003; 18.8 ± 4.2%, P=0.005). PADed-sx predicted PH with sensitivity (Se) = 36% and specificity (Sp) = 94% (cut-off 6.0 cm, AUC = 0.668, P=0.002), while PADI[/PADps] predicted PH with Se = 43% and Sp = 92% (cut-off 13.7%, AUC = 0.662, P=0.004). In the absence of TR, PADed-sx and the end-diastolic long-axis aortic diameter-to-PADed-sx ratio (AoDed-lx/PADed-sx) were most suitable to diagnose PH. ConclusionPulmonary artery crosssectional (short-axis) diameter at end-diastole measured in a right-parasternal long axis view of the left ventricular outflow tract and Pulmonary artery distensibility index were moderately specific but not very sensitive to diagnosing PH. Nonetheless, they may be used as complementary indices suggesting PH in the absence of TR or PR.

THE ROLE OF CARDIOVASCULAR MAGNETIC RESONANCE IMAGING IN NONINVASIVE ASSESSMENT OF PULMONARY HYPERTENSION SEVERITY

Objective: Pulmonary hypertension characterized by structural and mechanical changes in pulmonary vascular bed. Invasively calculated pulmonary artery (PA) stiffness indeces are associated with mortality in pulmonary hypertension (PH). CMRI-derived pulmonary artery distensibility (PAD) index reflects vascular remodeling in patients with pulmonary PH. The aim of the study was to evaluate the relationship between noninvasive PAD index and invasive PA stiffness indeces and basic determinants of PH severity. Design and method: We included 48 pts with PH (mean age 42.8± 14.7 yrs, m:f = 13:35): 27 idiopathic pulmonary arterial hypertension pts, 5 pts scleroderma PAH, 6 corrected congenital heart disease and 10 with inoperable CTPEH. All pts underwent 6-min walk test (6MWT), right heart catheterization (RHC), ECHO, CMRI, cardiopulmonary exercise testing (CPX). PA stiffness index and elastic modulus were calculated using data from RHC and CMRI. Pulmonary artery distensibility index (%) were derived from cross-sectional images of the main PA on cardiac magnetic resonance imgaging. Results: We revealed increased PA stiffness index 6.1 (4.6–10.2) and elastic modulus 424 mm Hg (254-678), decreased PAD index in PH pts 10% (9 –16.5). There was a significant negative correlation between PAD index and PA stiffness index (r = –0.90; p &lt; 0.0001), so we derived the formula to calculate the invasive PA stiffness using noninvasive PAD index: PA stiffness index = 102.4/ PAD index. There was also a negative correlation between PAD and elastic modulus (r = –0.91; p &lt; 0,0001). Patients with decreased PAD index &lt; 20 % had higher NT-proBNP level (1558 (738-4341) versus 306 (178-370); p&lt;0.05), also ECHO signs of RV systolic dysfunction:lower TAPSE (1.7 ±0.4 cm versus 2.0±0.4 cm; p = 0,04), tricuspid annular systolic velocity (10±2 versus 12±1 cm/sec; p = 0,007), global RV myocardial deformation (13±4% versus 21±5%; p = 0,001) and RV fractional area change ( 24±7%; p = 0,02) and reduced cardiac output which were determined by RHC (4.0 ± 1.1 versus 4.9 ±1.2 l/min; p &lt; 0,05). Conclusions: Noninvasive CMRI-derived PA distensibility index strongly correlated with PA stiffness indeces, and may be used for noninvasive assessment of PH severity.

Reduced Pulmonary Artery Distensibility Predicts Persistent Pulmonary Hypertension and 2-Year Mortality in Patients with Severe Aortic Stenosis Undergoing TAVR

Post-TAVR persistent pulmonary hypertension (PH) is a better predictor of poor outcome than pre-TAVR PH. In this longitudinal study we sought to evaluate whether pulmonary artery (distensibility (DPA) measured on preprocedural ECG-gated CTA is associated with persistent-PH and 2-year mortality after TAVR. Three hundred and thirty-six patients undergoing TAVR between July 2012 and March 2016 were retrospectively included and followed for all-cause mortality until November 2017. All patients underwent retrospectively ECG-gated CTA prior to TAVR. Main pulmonary artery (MPA) area was measured in systole and in diastole. DPA was calculated as: [(area-MPAmax-area-MPAmin)/area-MPAmax]%. ROC analysis was performed to assess the AUC for persistent-PH. Youden Index was used to determine the optimal threshold of DPA for persistent-PH. Two groups were compared based on a DPA threshold of 8% (specificity of 70% for persistent-PH). Kaplan-Meier, Cox proportional-hazard, and logistic regression analyses were performed. The primary clinical endpoint was defined as persistent-PH post-TAVR. The secondary endpoint was defined as all-cause mortality 2 years after TAVR. Median follow-up time was 413 (interquartiles 339-757) days. A total of 183 (54%) had persistent-PH and 68 (20%) patients died within 2-years after TAVR. Patients with DPA<8% had significantly more persistent-PH (67% vs 47%, p<0.001) and 2-year deaths (28% vs 15%, p=0.006), compared to patients with DPA>8%. Adjusted multivariable regression analyses showed that DPA<8% was independently associated with persistent-PH (OR 2.10 [95%-CI 1.3-4.5], p=0.007) and 2-year mortality (HR 2.91 [95%-CI 1.5-5.8], p=0.002). Kaplan-Meier analysis showed that 2-year mortality of patients with DPA<8% was significantly higher compared to patients with DPA≥8% (mortality 28% vs 15%; log-rank p=0.003). DPA on preprocedural CTA is independently associated with persistent-PH and two-year mortality in patients who undergo TAVR.

Echocardiographic Assessment of the Pulmonary Vein to Pulmonary Artery Ratio in Canine Heartworm Disease.

A total of 151 naturally heartworm-infected and 66 healthy dogs were included in the study. The presence/absence of PH was based on the right pulmonary artery distensibility index (RPAD index < 29.5%), and the PV:PA ratio was echocardiographically measured by the time-motion mode (M mode) and two-dimensional mode (2D mode). Other echocardiographic parameters were also assessed (pulmonary trunk to aorta ratio, tricuspid regurgitation pressure gradient, and AT:ET ratio). The results of the PV:PA ratio showed a highly positive correlation between the M and 2D modes (r = 0.928). The PV:PA ratio obtained by the M mode was identified as the strongest predictor for RPAD index (R2 0.628, p < 0.0001) with a good diagnostic accuracy (AUC = 0.99). The results of PV/PA by the 2D mode showed a similar prediction for the RPAD index (R2 0.606, p < 0.0001) with a good diagnostic accuracy (AUC = 0.98). Both of the 2D and M modes' PV:PA ratios decreased significantly with the presence of PH. A cut-off value of ≤0.845 showed high sensitivity and specificity for the M mode (97% and 94%, respectively) and the 2D mode (96% and 93%, respectively). The PV:PA ratio may be useful as a complementary diagnostic method for the estimation of moderate or severe PH in dogs with heartworm.

Right Pulmonary Artery Distensibility Index in Heartworm Infected Dogs: Are the Different Methods Leading to Same Results?

Canine Heartworm Disease (HWD) is mainly a pulmonary vascular disease. The reduction of the Pulmonary Artery Distensibility (PAD) is an early index of pulmonary vascular disease. Echocardiographic evaluation of the Right Pulmonary Artery Distensibility index (RPADi) is calculated as the percentage change in diameter of the right pulmonary artery (RPA) between systole and diastole. Historically, two main methods have been used for RPADi calculation: The Venco method and Visser method; however, different hybrid methods have also been used by other authors. Therefore, it could be difficult for a clinician to decide which method to apply and how to interpret the results based on the reference values reported. The aim of this study was to compare the RPADi obtained by five different techniques (Venco classic, Venco modified, Visser classic, Visser modified 1, and Visser modified 2). The study design was a retrospective, single center, observational study. Forty-seven client-owned dogs were included. The measurements were performed off-line as an average of three consecutive cardiac cycles by a single investigator blinded to the dogs' diagnosis. The RPADi was satisfactorily obtained by all methods in all dogs. Intra-observer measurement variability was clinically acceptable both for systolic and diastolic measurements. Although the Bland-Altman test showed a statistical agreement between the various methods used to calculate the RPADi, these methods cannot be used interchangeably in a clinical setting. Instead, the measurement method and reference values should always be specified.

Cardiac geometry, as assessed by cardiac magnetic resonance, can differentiate subtypes of chronic thromboembolic pulmonary vascular disease.

Ventricular septal flattening reflects RV pressure overload in pulmonary arterial hypertension. Eccentricity index (EI) and pulmonary artery distensibility (PAD) correlate with pulmonary artery pressure. We assessed the utility of these using cardiac magnetic resonance (CMR) to assess for pulmonary hypertension (PH) in patients with chronic thromboembolic disease. This may allow non-invasive differentiation between patients who have chronic thromboembolic pulmonary hypertension (CTEPH) and those with pulmonary vascular obstructions without PH at rest, known as chronic thromboembolic pulmonary disease (CTEPD). Twenty patients without resting pulmonary hypertension, including ten with chronic thromboembolic disease, and thirty patients with CTEPH were identified from a database at the Scottish Pulmonary Vascular Unit. CMR and right heart catheter had been performed within 96 h of each other. Short-axis views at the level of papillary muscles were used to assess the EI at end-systole and diastole. Pulmonary artery distensibility was calculated using velocity-encoded images attained perpendicular to the main trunk. Eccentricity index at end-systole and end-diastole were higher in CTEPH compared to controls (1.3 ± 0.5 vs. 1.0 ± 0.01; p ≤ 0.01 and (1.22 ± 0.2 vs. 0.98 ± 0.01; p ≤ 0.01, respectively) and compared to those with CTED. PAD was significantly lower in CTEPH compared to controls (0.13 ± 0.1 vs. 0.46 ± 0.23; p ≤ 0.01) and compared to CTED. End-systolic EI and end-diastolic EI correlated with pulmonary vascular hemodynamic indices and exercise variables, including mean pulmonary arterial pressure (R0.74 and 0.75, respectively), cardiac output (R-value -0.4 and -0.4, respectively) NTproBNP (R-value 0.3 and 0.3, respectively) and 6-min walk distance (R-value -0.7 and -0.8 respectively). Pulmonary artery distensibility also correlated with 6-min walk distance (R-value 0.8). Eccentricity index and pulmonary artery distensibility can detect the presence of pulmonary hypertension in chronic thromboembolic disease and differentiate between CTEPH and CTED subgroups. These measures support the use of non-invasive tests including CMR for the detection pulmonary hypertension and may reduce the requirement for right heart catheterization.

Evaluation of Pulmonary Hypertension in Dogs with Heartworm Disease Using the Computed Tomographic Pulmonary Trunk to Aorta Diameter Ratio.

Simple SummaryPulmonary hypertension (PH) is a consequence of proliferative pulmonary endoarteritis caused by the parasite Dirofilaria immitis (heartworm). To date, the diagnosis is carried out through echocardiographic determinations, with the right pulmonary artery distensibility (RPAD) index being the gold standard for diagnosis of PH caused by heartworm. Given the high importance and frequency of PH in dogs, the study of the pulmonary trunk to aorta ratio (PT:Ao) determined by computed tomography (CT) was proposed to assess its usefulness in the diagnosis of PH, compared to the gold standard method. The results show that the PT:Ao ratio was reliable for detecting and staging the severity of moderate to severe PH in dogs with heartworm.Dirofilaria immitis causes proliferative pulmonary endoarteritis that leads to the appearance of chronic precapillary pulmonary hypertension (PH) in dogs. Pulmonary trunk to aorta ratio (PT:Ao ratio) obtained by computed tomography (CT) was studied and the quantitative measure of the diameters of the pulmonary trunk (PT), the descending thoracic aorta (DAo) and ascending thoracic aorta (AAo) were evaluated for the determination of the presence of moderate to severe PH in 59 dogs. The diagnosis of PH was echocardiographically determined, based on the determination of the right pulmonary artery distensibility (RPAD) index (<29.5%), and compared with other parameters for estimating PH. The results showed a very high concordance: 0.976 (p-value 0.000) between the two CT methods (PT:DAo and PT:AAo) with an excellent intraclass correlation coefficient > 0.95. Moreover, cut-off values of ≥1.111 for PT:DAo, and ≥1.057 for PT:AAo were determined for dogs with an RPAD index < 29.5%, which suggests a cut-off value between healthy dogs and the presence of PH. As has been previously published, The PT:Ao ratios did not determine the presence of mild PH, so the measurements cannot be considered useful for the early diagnosis of PH in dogs with heartworm.

Evaluation of acute phase proteins, adiponectin and endothelin-1 to determine vascular damage in dogs with heartworm disease (Dirofilaria immitis), before and after adulticide treatment

Previous studies have shown the existence of an acute phase response in dogs with heartworm (Dirofilaria immitis), probably caused by the vascular inflammation that occurs during the pathogenesis of this disease. In addition, it has been seen that this acute phase response persists after finishing treatment, especially in dogs with pulmonary hypertension (PH). Furthermore, echocardiographic studies have shown that PH and endarteritis appear to persist for at least 10 months after completion of adulticide treatment, suggesting that the vascular changes in these dogs may not be reversible. Therefore, the objective of this study was to evaluate the serum concentrations of different positive acute phase proteins (APP) [C reactive-protein (CRP), haptoglobin and ferritin] and negative APP (albumin and paraoxonase-1 (PON-1)), and the usefulness of the endothelin-1 (ET-1) and adiponectin, in dogs infected by D. immitis to evaluate their usefulness as diagnostic biomarkers of vascular damage and PH and their progression throughout therapy up to 7 months after the end of adulticide treatment. Twenty-five heartworm-infected dogs received adulticide treatment, and serum measurements were performed on the day of diagnosis (day 0), day of discharge (day 90), and 6 months after discharge (day 270). In addition, presence or absence of PH was also echocardiographically determined using the Right Pulmonary Artery Distensibility Index. PH was present in 44% of the dogs on day 0 and day 90, and in 48% of dogs on day 270. Alterations were observed in the concentrations of all APP throughout the study, persisting the alterations in PON-1 and ferritin on day 270. Depending on the presence or absence of PH, CRP showed significant differences throughout the study, as did ET-1. On the other hand, adiponectin did not show variations throughout the study, so it did not seem a useful marker in this disease. These results could reflect the possible persistence of vascular inflammation up to 7 months after finishing treatment, whether or not there was PH, and consolidate the study of APP as useful markers in heartworm disease. Moreover, persistent PH could be the consequent clinical manifestation in dogs with more severe vascular alterations so the study of APP, especially CRP, and ET-1 could be especially advantageous in these patients in the early evaluation of the disease, as well as for the determination of disease severity, monitoring therapeutic responses, and predicting outcomes.

​​Importance of Right Pulmonary Artery Distensibility Index in the Diagnosis and Management of Pulmonary Arterial Hypertension Secondary to Canine Dilated Cardiomyopathy

Background: The measurement of tricuspid regurgitant velocity is the commonly used non-invasive method for the diagnosis of pulmonary hypertension in dogs. It is anticipated that M-mode echocardiographic measurement of right pulmonary artery distensibility (RPAD) index is simple and provides accurate means for the diagnosis of pulmonary arterial hypertension when tricuspid regurgitant velocity is absent. Hence this study was undertaken to evaluate the importance of RPAD index in the diagnosis and management of pulmonary arterial hypertension secondary to dilated cardiomyopathy. Methods: In the present study, a total of 165 dogs were subjected to echocardiography for diagnosis of pulmonary hypertension secondary to dilated cardiomyopathy. The maximum and minimum internal diameter of the right pulmonary artery during systole and diastole were quantified respectively to determine the right pulmonary artery distensibility (RPAD) index in right parasternal short axis M-mode echocardiogram. The M-mode morphology of right pulmonary artery (anterior dicrotic notch) also recorded. Result: Out of 165 dogs ten dogs had pulmonary arterial hypertension with dilated cardiomyopathy. Dogs with pulmonary hypertension showed a significant decrease in the mean right pulmonary artery distensibility index values and Acceleration time/Ejection time (AT/ET) ratio, while the mean tricuspid regurgitant systolic pressure gradient (TRPG) were significantly elevated when compared to the respective control group. The significant difference was observed in the mean values of tricuspid regurgitant systolic pressure gradient and RPAD index before and after the treatment.

Abstract 10288: Reduced Pulmonary Artery Distensibility: A Predictor of Persistent Pulmonary Hypertension and 2-Year Mortality Post-Transcatheter Aortic Valve Replacement in High-Risk Patients with Severe Aortic Stenosis

Introduction: Persistent pulmonary hypertension (PH) post-TAVR is a better predictor of poor outcome than pre-TAVR PH, possibly due to longstanding vascular damage involving loss of pulmonary artery (PA) elasticity. In this study we sought to evaluate whether PA distensibility (D PA ) measured on pre-procedural ECG-gated CTA is associated with persistent-PH and 2-year mortality after TAVR. Hypothesis: Reduced D PA is a predictor of persistent-PH and mortality post-TAVR. Methods: 336 patients undergoing TAVR between July 2012 and March 2016 were retrospectively included. All patients underwent retrospectively ECG-gated CTA of the chest, with reconstruction of 10 phases over the cardiac cycle (0%- 90% of the R-R interval) prior to TAVR. Patients were followed for all-cause mortality. Main pulmonary artery (MPA) area was measured at 20% (area-MPA 20 ) and 80% (area-MPA 80 ) of the R-R interval. D PA was calculated as follows: [(area-MPA 20 -area-MPA 80 )/area-MPA 20 ]%. Persistent-PH was defined as pre-TAVR RVSP&gt;35mmHg which persisted &gt;35mmHg in post-TAVR echocardiography. 2 groups were compared based on D PA &lt;8% (specificity of 70% for persistent-PH). Kaplan-Meier, Cox proportional-hazard and logistic regression analyses were performed. Results: Median follow-up time was 413 (interquartiles 339-757) days. A total of 68 (20%) patients died within 2 years after TAVR and 183 (54%) had persistent-PH. Those with D PA &lt;8% had significantly more atrial fibrillation (50% vs 35%, p&lt;0.001), 2-year deaths (28% vs 15%, p=0.006) and persistent-PH (67% vs 47%, p&lt;0.001), compared to those with D PA &gt;8%. Multivariable regression analyses adjusted for age, sex, STS-score, cardiac risk, frailty≥2 and NYHA≥III, showed that D PA &lt;8% was independently associated with two-year mortality (HR 2.91 [95%-CI 1.5-5.8], p=0.002) and persistent-PH (OR 2.10 [95%-CI 1.3-4.5], p=0.007). Kaplan-Meier analysis showed that mortality of patients with D PA &lt;8% was significantly higher compared to patients with D PA ≥8% (mortality 28% vs 15%; log-rank p=0.003). Conclusion: D PA on pre-procedural CTA is independently associated with persistent-PH and two-year mortality in patients who undergo TAVR and could be a valuable parameter for risk stratification of TAVR candidates.

Branch Pulmonary Artery Regurgitation in Repaired Tetralogy of Fallot: Correlation with Pulmonary Artery Morphology, Distensibility, and Right Ventricular Function.

Background: The aim was to determine the effect of pulmonary artery (PA) morphology on the branch pulmonary artery-regurgitation fraction (BPA-RF), the relationship of pulmonary insufficiency (PI) to BPA-RF and PA-distensibility, and factors (BPA-RF and PA-distensibility) associated with right ventricular function (RVF) in repaired tetralogy of Fallot (rTOF). Methods: A total of 182 rTOF patients (median age 17.1 years) were analyzed for length, angle of PA, BPA-RF, PI, and PA-distensibility, using magnetic resonance imaging. Results: The left PA had a significant greater RF than the right PA (median (interquartile range)): LPA 43.1% (32.6–51.5) and RPA 35.2% (24.7–44.7), p < 0.001. The LPA was shorter with a narrower angle than the RPA (p < 0.001). The anatomy of the branch-PA was not a factor for the greater LPA-RF (odds ratio, 95% confidence interval: CI, p-value): length 0.44 (0.95–2.00), p = 0.28; angle 0.63 (0.13–2.99), p = 0.56. There was a strong positive correlation between PI and BPA-RF-coefficients (95% CI), p-value: LPA 0.78% (0.70–0.86), p < 0.001; RPA 0.78% (0.71–0.84), p < 0.001 and between BPA-RF and distensibility-coefficients (95%CI), p-value: LPA 0.73% (0.37–1.09), p < 0.001; RPA 1.63% (1.22–2.03), p < 0.001, respectively. The adjusted BPA-RF did not predict RVF, RPA (p = 0.434), LPA (p = 0.268). Conclusions: PA morphology is not a significant factor for the differential BPA-RF. The vascular wall in rTOF patients responds to chronic increased intravascular volume by increasing distensibility. BPA-RF is not a determinant of RVF.

Prognostic implications of pulmonary wave reflection and reservoir pressure in patients with pulmonary hypertension

BackgroundRight ventricular (RV) coupling to the pulmonary circulation influences the response of the RV to the increased afterload caused by pulmonary hypertension (PH), which ultimately determines prognosis. A methodology that accounts for pulsatile flow is required when assessing ventriculo-arterial coupling. We applied wave intensity analysis (WIA) methods to assess the compliance of the main pulmonary artery (PA) in patients with or without PH and compared this to PA distensibility, RV function and clinical outcomes. MethodsHigh-fidelity blood pressure and Doppler flow velocity tracings were obtained simultaneously during cardiac catheterisation for suspected PH. RV volumes, main PA distensibility and ventriculo-arterial coupling (Emax/Ea) were analysed using cardiovascular magnetic resonance. ResultsThe study included 17 ​PH patients and 6 controls. Wave speed, reservoir and excess pressure were higher in PH patients compared to controls (p ​< ​0.01 for all). Waveforms relating to RV ejection, microvascular wave reflection and late systolic proximal deceleration were higher in PH patients compared to controls (p ​< ​0.01 for all) and related to echocardiographic findings, including PA Doppler notching and shortened acceleration time. Wave speed, reservoir pressure and excess pressure were strongly correlated to main PA distensibility, RV function and Emax/Ea. A higher total pressure integral was associated with an increased risk of death (all-cause mortality). ConclusionThe reservoir-excess pressure model, in combination with conventional clinical imaging, provides valuable information on the pathophysiology of PH that standard haemodynamic parameters do not. Future studies should further investigate the prognostic implications of WIA in PH, and its potential role in clinical practice.

Reduced Pulmonary Artery Distensibility Is Independently Associated With 2-year Mortality In Transcatheter Aortic Valve Replacement Patients: A Retrospective Longitudinal Study

Introduction: Recent studies have shown that pulmonary artery (PA) distensibility on pre-TAVR ECG-gated CTA scans can detect PH due to left heart disease. In this longitudinal study we sought to evaluate whether PA distensibility measured on pre-procedural CTA is associated with 2-year mortality after TAVR.

Decreased pulmonary artery distensibility as a marker for severity in acute pulmonary embolism patients undergoing ECG-gated CTPA.

To investigate the characteristics of pulmonary artery distensibility(PAD) in patients with acute pulmonary embolism (APE) and to assess whether a relationship exists between PAD and the disease severity. Clinical and radiological data of 30 APE patients who underwent retrospective electrocardiogram (ECG)-gated computed tomography pulmonary angiography (CTPA) with a definite diagnosis of APE were retrospectively reviewed in the present study, including 15 subjects in severe (SPE) group and 15 subjects in non-severe (NSPE) group. PAD and cardiac function parameters were compared between the two groups, their relationships were investigated, and receiver operating characteristic (ROC) curves were used to determine the sensitivity and specificity of the above parameters for the diagnosis of APE severity. The PAD decreased in the following order: NSPE group (6.065 ± 2.114) × 10-3 (%/mmHg), and SPE group (4.334 ± 1.777) × 10-3 (%/mmHg) (P < 0.05). All the cardiac function parameters except RA/LAdiameter showed statistically significant different values between the two groups (P < 0.05). As APE severity increased, the cardiac morphological measurements of RV/LVdiameter, RV/LVarea, RVEDV/LVEDV and RVESV/LVESV increased. There was a weak to moderate negative correlation between PAD and PAmax, PAmin, PA/AAmin, PA/AAmax, RV/LVdiameter, RV/LVarea (r = -0.393 to -0.625), that is, PAD was inversely correlated with cardiac function parameters. There was a moderate negative correlation between PAD and hemoptysis(r = -0.672). The area under the ROC curve (AUC) of PAD was 0.724, the critical value was 4.137 × 10-3 mm/Hg, and the sensitivity and specificity were 60.0% and 93.3%, respectively. PAmin showed the strongest discriminatory power to identify high-risk patients (AUC = 0.827), with the highest sensitivity of 100%, which was also achieved by RA/LAarea. The PAD obtained by retrospective ECG-gated CTPA could be an indicator to be used in the evaluation of the presence and severity of APE.

Evaluation of Right Ventricular Functions and Pulmonary Artery Distensibility in Patients with Pulmonary Hypertension Using Cardiac Magnetic Resonance Imaging

Evaluation of Right Ventricular Functions and Pulmonary Artery Distensibility in Patients with Pulmonary Hypertension Using Cardiac Magnetic Resonance Imaging