Search

End points that are repeatable and sensitive to change are important in pulmonary arterial hypertension (PAH) for clinical practice and trials of new therapies. In 42 patients with PAH, test–retest repeatability was assessed using the intraclass correlation coefficient and treatment effect size using Cohen’s d statistic. Intraclass correlation coefficients demonstrated excellent repeatability for MRI, 6 min walk test and log to base 10 N-terminal pro-brain natriuretic peptide (log10NT-proBNP). The treatment effect size for MRI-derived right ventricular ejection fraction was large (Cohen’s d 0.81), whereas the effect size for the 6 min walk test (Cohen’s d 0.22) and log10NT-proBNP (Cohen’s d 0.20) were fair. This study supports further evaluation of MRI as a non-invasive end point for clinical assessment and PAH therapy trials.Trial registration number NCT03841344.

This study aimed to determine the prognostic value of cardiovascular magnetic resonance (CMR) in patients with heart failure with preserved ejection fraction and associated pulmonary hypertension (pulmonary hypertension-HFpEF). Patients with pulmonary hypertension-HFpEF were recruited from the ASPIRE registry and underwent right heart catheterisation (RHC) and CMR. On RHC, the inclusion criteria was a mean pulmonary artery pressure (MPAP) ≥ 25 mmHg and pulmonary arterial wedge pressure > 15 mmHg and, on CMR, a left atrial volume > 41 ml/m2 with left ventricular ejection fraction > 50%. Cox regression was performed to evaluate CMR against all-cause mortality. In this study, 116 patients with pulmonary hypertension-HFpEF were identified. Over a mean follow-up period of 3 ± 2 years, 61 patients with pulmonary hypertension-HFpEF died (53%). In univariate regression, 11 variables demonstrated association to mortality: indexed right ventricular (RV) volumes and stroke volume, right ventricular ejection fraction (RVEF), indexed RV mass, septal angle, pulmonary artery systolic/diastolic area and its relative area change. In multivariate regression, only three variables were independently associated with mortality: RVEF (HR 0.64, P

Rationale: Pulmonary arterial hypertension (PAH) is a life-shortening condition. The European Society of Cardiology and European Respiratory Society and the REVEAL (North American Registry to Evaluate Early and Long-Term PAH Disease Management) risk score calculator (REVEAL 2.0) identify thresholds to predict 1-year mortality. Objectives: This study evaluates whether cardiac magnetic resonance imaging (MRI) thresholds can be identified and used to aid risk stratification and facilitate decision-making. Methods: Consecutive patients with PAH (n = 438) undergoing cardiac MRI were identified from the ASPIRE (Assessing the Spectrum of Pulmonary Hypertension Identified at a Referral Center) MRI database. Thresholds were identified from a discovery cohort and evaluated in a test cohort. Measurements and Main Results: A percentage-predicted right ventricular end-systolic volume index threshold of 227% or a left ventricular end-diastolic volume index of 58 ml/m2 identified patients at low (10%) risk of 1-year mortality. These metrics respectively identified 63% and 34% of patients as low risk. Right ventricular ejection fraction >54%, 37–54%, and

Background Pulmonary hypertension (PH) is debilitating disease characterized by a progressive increase in pulmonary arterial pressure (PAP) that leads to right ventricular (RV) failure and death. Mixed venous oxygen saturation (SVO2) represents the oxygen saturation of blood returning to the lungs before reaching the alveolo-capillary units. SVO2 is strongly associated with clinical outcomes in PH. The relationship of non-invasive CMR metrics to this prognostically relevant parameter in patients with PH are unknown. Purpose This study sought to develop an early understanding of which CMR volumetric and flow parameters are most associated with SVO2. Methods Eighteen (n=18) patients were prospectively recruited at a large tertiary PH unit. The SVO2 was measured during right heart catheterisation. All patients had CMR on the 1.5 T scanner (HDx scanner, GE Healthcare, Waukesha, Wisconsin, USA), using an 8-channel cardiac coil. Subjects were scanned in the supine position with electrocardiogram (ECG) gating. CMR protocol included long and short axis cines and through-plane pulmonary artery phase contrast acquisition. The velocity encoded images were analysed for the following: mean pulmonary artery (MPA) systolic velocity, MPA stroke volume, MPA wall shear stress (WSS) and wall shear rate (WSR). The 4 chamber cine was used to measure end-diastolic right atrial (RA) area. RV volumes were analysed using standard methods. Stepwise multiple regression model of significantly associated parameters (p Results The left ventricular and RV volumetric functional parameters demonstrated no association to SVO2 (p>0.05) in any of the participants. However, a negative association was shown between RA area and SVO2 (R=−0.57, p=0.01). The only other parameter which correlated with SVO2 was MPA stroke volume (R=0.5, p=0.03). In stepwise multiple regression, both parameters demonstrated independent association to SVO2. The predictive values generated by a combined model demonstrated high correlation to measured SVO2 (R=0.73, p Conclusion(s) RA area and MPA stroke volume are independently associated with SVO2. A novel CMR prediction model comprised of these two metrics, demonstrates high association to the measured SVO2 by invasive haemodynamic study. Further work to determine reproducibility and reliability is needed before this method becomes an important prognostic tool for PH patients.

Background Pulmonary hypertension (PH) is defined by a resting mean pulmonary artery pressure (mPAP) ≥25 mmHg by right heart catheterization. Systolic pulmonary artery pressures are used as surrogate non-invasive markers of PH. A direct prediction tool of non-invasive mPAP would provide the capacity to diagnose disease through non-invasive means. It remains unclear if a multi-parametric cardiac magnetic resonance (CMR) integrated approach can provide an accurate measure of invasive mPAP. Purpose This study sought to develop a novel CMR model using both established and newly derived CMR metrics for estimating mean pulmonary artery pressure. Methods 18 patients were prospectively recruited at a large tertiary PH unit. All patients underwent right heart catheterisation (RHC) and CMR on the 1.5 T scanner (HDx scanner, GE Healthcare, Waukesha, Wisconsin, USA), using an 8-channel cardiac coil. CMR protocol included long and short axis cines and through-plane pulmonary artery phase contrast acquisition. The velocity encoded images were analysed for the following: mean pulmonary artery pan-systolic velocity (PASV), MPA stroke volume, MPA wall shear stress (WSS) and wall shear rate (WSR). The 4-chamber cine was used to measure end-diastolic right atrial area. Right ventricular volumes were analysed using standard methods. Stepwise multiple regression model of significantly associated parameters (p Results Mean age of the 18 patients was 68.78±7.46 years (44% males). The following CMR metrics demonstrated significant association to the measured mPAP: RA area (r=0.65 p=0.03); MPA mean pan-systolic velocity (r=−0.57 p=0.01); RVEDV (r=0.52 p=0.03); RVEF (r=−0.40 p=0.10); RVESV (r=0.58 p=0.01). In stepwise multiple regression, only two parameters demonstrated independent association to mPAP - RA Area and MPA mean pan-systolic velocity. The predicted mPAP demonstrated good correlation to the measured mPAP (R=0.76, p Conclusion(s) Mean pulmonary artery systolic velocity and right atrial area are independently associated with mPAP. Ournovel CMR prediction model for mPAP, comprising of these two metrics, demonstrates high association to the measured mPAP by invasive haemodynamic study.

Purpose To assess interventricular septal (IVS) angle in the identification of combined pre- and postcapillary pulmonary hypertension (Cpc-PH) in patients with pulmonary hypertension (PH) due to left-sided heart disease. Materials and Methods In this retrospective study, consecutive, incident patients suspected of having PH underwent same-day right-sided heart catheterization (RHC) and MRI at a PH referral center between April 2012 and April 2017. The diagnostic accuracy of the IVS angle to identify Cpc-PH in patients with pulmonary arterial wedge pressure (PAWP) greater than 15 mmHg was assessed by using receiver operator characteristic curves, sensitivity, specificity, and negative and positive predictive values. IVS angle also was assessed as a predictor of all-cause mortality by using Cox uni- and multivariable proportional hazards regression. Results A total of 708 patients underwent same-day MRI and RHC, and 171 patients had PAWP greater than 15 mmHg. Mean age was 70 years (range, 21-90 years) (women: mean age, 69 years; range, 21-88 years) (men: mean age, 71 years; range, 43-90 years). Systolic IVS angle correlated with diastolic pulmonary gradient (DPG) (r = 0.739, P.001). Receiver operating characteristic curve analysis showed septal angle enabled identification of Cpc-PH (DPG ≥ 7), with an area under the receiver operating characteristic curve of 0.911 (P.001). A 160° threshold, derived from the first half of patients with raised PAWP, enabled identification of a DPG of at least 7 mmHg with 67% sensitivity and 93% specificity (P.001) in the second cohort of patients with raised PAWP. IVS angle was predictive of all-cause mortality (standardized univariable hazard ratio, 1.615; P.01). Conclusion The systolic interventricular septal angle is elevated in patients with combined pre- and postcapillary pulmonary hypertension and enables one to predict those patients who have PH due to left-sided heart disease who have an increased risk of death. Published under a CC BY 4.0 license. Online supplemental material is available for this article.

Introduction: Pulmonary arterial hypertension (PAH) is a severe, low survival and rapidly progressive disease, characterised by an increase in the distal vascular resistance and decrease in the compliance. Right heart catheterisation (RHC) is the standard procedure for the PAH diagnosis and regular response to therapy assessment. Although the severe RHC associated risks are reduced, minimising the number of the interventions is highly desirable for improving patients9 life quality. Aim: The aim of the current study is to evaluate whether non-invasive measures of pulmonary vascular resistance and compliance can be used to assess the response to treatment in PAH patients. Methods: 93 patients diagnosed with PAH at RHC, underwent magnetic resonance imaging (MRI) of the main pulmonary artery at baseline and one year follow-up. At baseline, 56 patients were treatment naive and 37 on PAH therapy. A 3-element Windkessel model, using as input MRI flow and area waveforms, was implemented to compute the pulmonary resistance, R Wk and compliance, C Wk (Lungu et al., J Biomech 2014; 47:2941-7). R Wk and C Wk were compared at baseline with invasive pulmonary resistance, PVR, and vascular compliance, C SV computed as stroke volume to pulse pressure ratio. Results: At baseline, R Wk correlated with PVR (p Wk correlated with C SV (p Wk (p Wk (p Conclusion: The non-invasive proposed metrics have the potential to assess the response to PAH therapy, reducing the RHC interventions at follow-up.

Introduction: T1 elevation has been observed in the right ventricular (RV) insertion points of pulmonary hypertension (PH) patients and animal models (Spruijt, O., et al., JCMR, 2015; 17(1): 44; Garcia-Alvarez, A., et al., JACC, 2015. 8(1):76-82) however the association with cardiac remodelling and function metrics in patients with PH is incompletely understood. Objective: To characterise native myocardial T1 values in patients with PH in comparison to right ventricular function and remodelling. Method: 204 patients with suspected PH (59±17 years, 56% F) and 34 healthy volunteers (50±15 years, 50% F) underwent MRI at 1.5T, including a Modified Look Locker Inversion Recovery T1 mapping sequence. 142/204 patients had a diagnosis of PH and PCWP Results: Patients with PH had elevated myocardial T1 values compared to healthy volunteers (superior RV insertion point: p=0.004; inferior RV insertion point: p=0.005). Within patients with PH, systolic septal angle correlated positively with RV insertion point T1 (superior: r= 0.258, p=0.003; inferior: r=0.291, p=0.021) and septal T1 (r=0.188, p=0.031). RV insertion point T1 correlated with RV mass index (superior: r=0.293 p=0.001; inferior: r=0.173, p=0.043). Conclusion: T1 elevation correlates with a larger RV mass and a greater septal angle in patients with PH.

CTEPH is a potentially curable cause of pulmonary hypertension. V/Q scintigraphy is recommended for screening but requires exposure to ionising radiation. 3D lung perfusion MRI has been shown to have similar sensitivity for diagnosing CTEPH, compared to planar perfusion scintigraphy, however planar imaging has now been largely replaced by SPECT. Our aim was to assess the diagnostic accuracy of MRI perfusion against perfusion SPECT in CTEPH screening. METHODS & RESULTS: One year of consecutive suspected CTEPH patients attending a PH centre with perfusion MRI, perfusion SPECT and CTPA within 14 days were included. MR, SPECT and CTPA were independently analysed by two blinded radiologists. Disagreements were corrected by consensus. 74 suspected CTEPH patients attended for perfusion MRI, SPECT and CTPA. 46 were diagnosed with CTEPH/CTED at the PH MDT. 3D MRI lung perfusion correctly identified all patients, (100% sensitivity), compared to 96% sensitivity for SPECT. There was 1 indeterminate SPECT case and 2 indeterminate MRI cases. DISCUSSION: Lung perfusion MRI has increased sensitivity compared with perfusion scintigraphy in CTEPH. As MRI does not use ionising radiation and is an established part of the PH patient pathway it is a worthy screening test for suspected CTEPH.

Objective.Pulmonary arterial hypertension (PAH) is a life-threatening complication of connective tissue diseases (CTD). Our aim was to compare the diagnostic utility of noninvasive imaging modalities, i.e., magnetic resonance imaging (MRI), computed tomography (CT), and echocardiography, in evaluation of these patients.Methods.In total, 81 consecutive patients with CTD and suspected PH underwent cardiac MRI, CT, and right heart catheterization (RHC) within 48 hours. Functional cardiac MRI variables [ventricle areas and ratios, delayed myocardial enhancement, position of the interventricular septum, right ventricular mass, ventricular mass index (VMI), and pulmonary artery distensibility] were all evaluated. The pulmonary artery size, pulmonary artery/aortic ratio (PA/Ao), left and right ventricular (RV) diameter ratio, RV wall thickness, and grade of tricuspid regurgitation were measured on CT. Tricuspid gradient (TG) and size of the RV were assessed using echocardiography.Results.In our study of 81 patients with CTD, 55 had PAH, 22 had no PH, and 4 had PH owing to left heart disease. There was good correlation between mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR) measured by RHC and VMI derived from MRI (mPAP, r = 0.69, p < 0.001; PVR, r = 0.78, p < 0.001) and systolic area ratio (mPAP, r = 0.69, p < 0.001; PVR, r = 0.68, p < 0.001) and TG derived from echocardiography (mPAP, r = 0.84, p < 0.001; PVR, r = 0.76, p < 0.001). In contrast, CT measures showed only moderate correlation. MRI and echocardiography each performed better as a diagnostic test for PAH than CT-derived measures: VMI ≥ 0.45 had a sensitivity of 85% and specificity 82%; and TG ≥ 40 mm Hg had a sensitivity of 86% and specificity 82%. Univariate Cox regression analysis showed the MRI measurements were better at predicting mortality. Patients with RV end diastolic volume < 135 ml had a better prognosis than those with a value > 135 ml, with a 1-year survival of 95% versus 66%, respectively.Conclusion.In patients with CTD and suspected PAH, cardiac MRI and echocardiography have greater diagnostic utility than CT in the assessment of patients with suspected PAH, and MRI has prognostic value.

To evaluate the utility of 1.5-T noncontrast magnetic resonance (MR) imaging of the lung parenchyma and to compare it with computed tomography (CT) in the assessment of interstitial lung disease and other morphologic lung abnormalities.Institutional review board approval was obtained for retrospective image analysis. A total of 236 patients who underwent MR imaging and CT as part of their assessment for suspected pulmonary hypertension were included in this study. Lung MR imaging was performed with a 1.5-T system as a stack of axial two-dimensional balanced steady-state free precession (bSSFP) acquisitions. Two radiologists independently evaluated CT and MR images for various morphologic abnormalities, such as pulmonary fibrosis, pleural and mediastinal disease, solid lesions, bronchial disease, and emphysema. Κ statistics were used to measure interobserver agreement.Sensitivity and specificity of MR imaging in the identification of pulmonary fibrosis (n = 46) were 89% (95% confidence interval: 77%, 96%) and 91% (95% confidence interval: 76%, 98%), respectively, when compared with CT. In comparison to CT, MR imaging depicted 75% of ground-glass opacities. Nine of the 12 noncalcified nodules were identified on MR images. Lung nodules (75%, κ = 0.71) and effusions (100%, κ = 0.89) were also well visualized on MR images. MR imaging was however less effective in depicting emphysema (16%, κ = 0.60) and minor fibrosis (67%, κ = 0.79).This study shows bSSFP MR imaging is inferior to CT in imaging parenchymal lung disease; however, this study does demonstrate for the first time a potential role for the bSSFP sequence as an alternative radiation-free noncontrast imaging modality for use in patients with pulmonary fibrosis.

To evaluate the diagnostic accuracy of contrast-enhanced MR angiography (CE-MRA) and the added benefit of unenhanced proton MR angiography compared with CT pulmonary angiography (CTPA) in patients with chronic thromboembolic disease (CTE). A 2 year retrospective study of 53 patients with chronic thromboembolic pulmonary hypertension who underwent CTPA and MRI for suspected pulmonary hypertension and a control group of 36 patients with no CT evidence of pulmonary embolism. The MRI was evaluated for CTE and the combined diagnostic accuracy of ce-MRA and unenhanced proton MRA was determined. CE-MRA generated lung perfusion maps were also assessed. The overall sensitivity and specificity of CE-MRA in diagnosing proximal and distal CTE were 98% and 94%, respectively. The sensitivity improved from 50% to 88% for central vessel disease when CE-MRA images were analysed with unenhanced proton MRA. The CE-MRA identified more stenoses (29/18), post-stenosis dilatation (23/7) and occlusions (37/29) compared with CTPA. The CE-MRA perfusion images showed a sensitivity of 92% for diagnosing CTE. CE-MRA has high sensitivity and specificity for diagnosing CTE. The sensitivity of CE-MRA for visualisation of adherent central and lobar thrombus significantly improves with the addition of unenhanced proton MRA which delineates the vessel wall.

Background A transpulmonary gradient (TPG)>12mmHg is thought to represent evidence of vascular change beyond that expected from passive pulmonary venous congestion in patients with pulmonary hypertension and left heart disease (PH-LHD). However recent studies found those with a diastolic pressure gradient (DPG) >6 to have a worse survival. This has led to a change in the recent guidelines suggesting 2 types of PH-LHD: “isolated post-capillary PH” (pulmonary arterial wedge pressure (PAWP)>15 mm Hg and DPG 15 mm Hg and DPG≥7 mmHg). It would be advantageous if a non-invasive method of predicting DPG could be found for both prognostication and to identify potential patients for clinical trials of targeted therapies. Our aim was investigate the utility of cardiac magnetic resonance (CMR) imaging for estimation of DPG in patients with PH-LHD.

The volumetric flow rate (VFR) waveform over the cardiac cycle in the cerebral vasculature is a significant factor in many studies, which involve cerebrovascular function. Perhaps contrary to expectation, the literature in this area is sparse and the characteristics of blood flow waveforms are ill defined. A better understanding of the variation of blood flow rate and pulsatility may aid our knowledge of risk factors involved in diseases and conditions, such as stroke, arteriovenous malformation, or aneurysm rupture. This study sought to characterise the blood flow waveform over the cardiac cycle at levels within the carotid artery and basilar artery (BA) in a normal cohort. The study cohort consisted of 22 subjects (recruitment age: 20 to 40 years) with no history of vascular disease (median age=26 years, interquartile range=25 to 32 years). Two-dimensional quantitative phase-contrast magnetic resonance imaging was performed on each subject at nine anatomic locations within the carotid artery and BA. Significant differences in pulsatility were present within the carotid tree. Archetypal VFR waveforms were established for this group at the nine locations. A normal individual's VFR waveform at a location within the carotid tree can be estimated by taking the group's archetypal waveform for that location, and scaling by the individual's average flow rate.

Background Chronic thromboembolic pulmonary hypertension (CTEPH) is a complication of pulmonary embolism potentially curable by surgery. Perfusion scintigraphy is currently advocated as the imaging modality of choice to exclude CTEPH due to its high sensitivity. We have evaluated the diagnostic utility of lung perfusion MRI. Methods Consecutive patients attending a pulmonary hypertension referral centre undergoing lung perfusion MRI, perfusion scintigraphy, CT pulmonary angiography (CTPA) and right heart catheterisation within 14 days were identified. Results Of 132 patients, 78 were diagnosed as having CTEPH. Lung perfusion MRI correctly identified 76 patients as having CTEPH with an overall sensitivity of 97%, specificity 92%, positive predictive value 95% and negative predictive value 96% compared with perfusion scintigraphy (sensitivity 96%, specificity 90%) and CTPA (sensitivity 94%, specificity 98%). No cases of surgically accessible CTEPH were missed with either modality. Conclusions Lung perfusion MRI has high sensitivity equivalent to perfusion scintigraphy in diagnosing CTEPH but does not require ionising radiation, making it an attractive initial imaging modality to assess patients with suspected CTEPH.