Project description: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 (<5%) and high (>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 <37% identified 21%, 43%, and 36% of patients at low, intermediate, and high risk, respectively, of 1-year mortality. At follow-up cardiac MRI, patients who improved to or were maintained in a low-risk group had a 1-year mortality <5%. Percentage-predicted right ventricular end-systolic volume index independently predicted outcome and, when used in conjunction with the REVEAL 2.0 risk score calculator or a modified French Pulmonary Hypertension Registry approach, improved risk stratification for 1-year mortality.Conclusions: Cardiac MRI can be used to risk stratify patients with PAH using a threshold approach. Percentage-predicted right ventricular end-systolic volume index can identify a high percentage of patients at low-risk of 1-year mortality and, when used in conjunction with current risk stratification approaches, can improve risk stratification. This study supports further evaluation of cardiac MRI in risk stratification in PAH.
Project description:Rationale: Patients with bronchopulmonary dysplasia (BPD)-associated pulmonary hypertension (PH) have increased morbidity and mortality. Noninvasive assessment relies on echocardiograms (echos), which are technically challenging in this population. Improved assessment could augment decisions regarding PH therapies.Objectives: We hypothesized that neonatal cardiac magnetic resonance imaging (MRI) will correlate with BPD severity and predict short-term clinical outcomes, including need for PH therapies for infants with BPD.Methods: A total of 52 infants (31 severe BPD, 9 moderate BPD, and 12 with either mild or no BPD) were imaged between 39 and 47 weeks postmenstrual age on a neonatal-sized, neonatal ICU-sited 1.5-T magnetic resonance (MR) scanner. MR left ventricular eccentricity index (EI), main pulmonary artery-to-aorta (PA/AO) diameter ratio, and pulmonary arterial blood flow were determined. Echos obtained for clinical indications were reviewed. MRI and echo indices were compared with BPD severity and clinical outcomes, including length of stay (LOS), duration of respiratory support, respiratory support at discharge, and PH therapy.Measurements and Main Results: PA/AO ratio increased with BPD severity. Increased PA/AO ratio, MR-EI, and echo-EIs were associated with increased LOS and duration of respiratory support. No correlation was seen between pulmonary arterial blood flow and BPD outcomes. Controlling for gestational age, birth weight, and BPD severity, MR-EI was associated with LOS and duration of respiratory support. Increased PA/AO ratio and MR-EI were associated with PH therapy during hospitalization and at discharge.Conclusions: MRI can provide important image-based measures of cardiac morphology that relate to disease severity and clinical outcomes in neonates with BPD.
Project description:ObjectivesTo provide a comprehensive overview of all reported cardiac magnetic resonance (CMR) findings that predict clinical deterioration in pulmonary arterial hypertension (PAH).MethodsMEDLINE and EMBASE electronic databases were systematically searched for longitudinal studies published by April 2015 that reported associations between CMR findings and adverse clinical outcome in PAH. Studies were appraised using previously developed criteria for prognostic studies. Meta-analysis using random effect models was performed for CMR findings investigated by three or more studies.ResultsEight papers (539 patients) investigating 21 different CMR findings were included. Meta-analysis showed that right ventricular (RV) ejection fraction was the strongest predictor of mortality in PAH (pooled HR 1.23 [95 % CI 1.07-1.41], p?=?0.003) per 5 % decrease. In addition, RV end-diastolic volume index (pooled HR 1.06 [95 % CI 1.00-1.12], p?=?0.049), RV end-systolic volume index (pooled HR 1.05 [95 % CI 1.01-1.09], p?=?0.013) and left ventricular end-diastolic volume index (pooled HR 1.16 [95 % CI 1.00-1.34], p?=?0.045) were of prognostic importance. RV and LV mass did not provide prognostic information (p?=?0.852 and p?=?0.983, respectively).ConclusionThis meta-analysis substantiates the clinical yield of specific CMR findings in the prognostication of PAH patients. Decreased RV ejection is the strongest and most well established predictor of mortality.Key points• Cardiac magnetic resonance imaging is useful for prognostication in pulmonary arterial hypertension. • Right ventricular ejection fraction is the strongest predictor of mortality. • Serial CMR evaluation seems to be of additional prognostic importance. • Accurate prognostication can aid in adequate and timely intensification of PAH-specific therapy.
Project description:AimsWe sought to identify metabolic pathways associated with right ventricular (RV) adaptation to pulmonary hypertension (PH). We evaluated candidate metabolites, previously associated with survival in pulmonary arterial hypertension, and used automated image segmentation and parametric mapping to model their relationship to adverse patterns of remodelling and wall stress.Methods and resultsIn 312 PH subjects (47.1% female, mean age 60.8 ± 15.9 years), of which 182 (50.5% female, mean age 58.6 ± 16.8 years) had metabolomics, we modelled the relationship between the RV phenotype, haemodynamic state, and metabolite levels. Atlas-based segmentation and co-registration of cardiac magnetic resonance imaging was used to create a quantitative 3D model of RV geometry and function-including maps of regional wall stress. Increasing mean pulmonary artery pressure was associated with hypertrophy of the basal free wall (β = 0.29) and reduced relative wall thickness (β = -0.38), indicative of eccentric remodelling. Wall stress was an independent predictor of all-cause mortality (hazard ratio = 1.27, P = 0.04). Six metabolites were significantly associated with elevated wall stress (β = 0.28-0.34) including increased levels of tRNA-specific modified nucleosides and fatty acid acylcarnitines, and decreased levels (β = -0.40) of sulfated androgen.ConclusionUsing computational image phenotyping, we identify metabolic profiles, reporting on energy metabolism and cellular stress-response, which are associated with adaptive RV mechanisms to PH.
Project description:BackgroundIn patients with pulmonary hypertension (PH), duration of vortical blood flow along the main pulmonary artery enables estimation of the mean pulmonary arterial pressure (mPAP) non-invasively. It remains to date not known, if this method is applicable in patients with pulmonary arterial hypertension (PAH) and abnormal aortic-to-pulmonary shunting.Case presentationThe present case analyzes the effect of a patent ductus arteriosus (PDA) on pulmonary artery flow patterns in PAH (mPAP from right heart catheterization, 75 mmHg). PH-associated vortical blood flow, which is typically observed rotating in a clockwise direction when viewed in right ventricular outflow tract orientation, was found nested in PDA left-to-right shunting. Even though rotating counter-clockwise, duration of vortical flow translated into correct non-invasive mPAP estimate.ConclusionsThis case indicates that PH-associated vortex rotation is not restricted to clockwise direction, and that vortex-based estimation of elevated mPAP might also be feasible in patients with PAH and PDA.
Project description:Prior work has described the relationship between pulmonary vascular pruning on computed tomography (CT) scans and metrics of right-sided heart dysfunction in smokers. In this analysis, we sought to look at pruning on a lobar level, as well as examine the effect of the arterial and venous circulation on this association.Automated vessel segmentation applied to noncontrast CT scans from the COPDGene Study in 24 subjects with cardiac magnetic resonance imaging scans was used to create a blood volume distribution profile. These vessels were then manually tracked to their origin and characterized as artery or vein.Assessment of pruning on a lobar level revealed associations between pruning and right ventricular function previously not observed on a global level. The right ventricular mass index, the right ventricular end-systolic volume index, and pulmonary arterial-to-aorta ratio were associated with both arterial and venous pruning, whereas right ventricular ejection fraction was associated with only arterial pruning.Lobar assessment and segmentation of the parenchymal vasculature into arterial and venous components provide additional information about the relationship between loss of vasculature on CT scans and right ventricular dysfunction.
Project description:BACKGROUND:Right ventricular (RV) function is a major determinant of outcome in patients with pulmonary hypertension. Cardiac magnetic resonance (CMR) is gold standard to assess RV ejection fraction (RVEFCMR), however this is a crude measure. New CMR measures of RV function beyond RVEFCMR have emerged, such as RV lateral atrio-ventricular plane displacement (AVPDlat), maximum emptying velocity (S'CMR), RV fractional area change (FACCMR) and feature tracking of the RV free wall (FWSCMR). However, it is not fully elucidated if these CMR measures are in parity with the equivalent echocardiography-derived measurements: tricuspid annular plane systolic excursion (TAPSE), S'-wave velocity (S'echo), RV fractional area change (FACecho) and RV free wall strain (FWSecho). The aim of this study was to compare regional RV function parameters derived from CMR to their echocardiographic equivalents in patients with pulmonary hypertension and to RVEFCMR. METHODS:Fifty-five patients (37 women, 62?±?15?years) evaluated for pulmonary hypertension underwent CMR and echocardiography. AVPDlat, S'CMR, FACCMR and FWSCMR from cine 4-chamber views were compared to corresponding echocardiographic measures and to RVEFCMR delineated in cine short-axis stack. RESULTS:A strong correlation was demonstrated for FAC whereas the remaining measurements showed moderate correlation. The absolute bias for S' was 2.4?±?3.0?cm/s (relative bias 24.1?±?28.3%), TAPSE/AVPDlat 5.5?±?4.6?mm (33.2?±?25.2%), FWS 4.4?±?5.8% (20.2?±?37.5%) and for FAC 5.1?±?8.4% (18.5?±?32.5%). In correlation to RVEFCMR, FACCMR and FWSecho correlated strongly, FACecho, AVPDlat, FWSCMR and TAPSE moderately, whereas S' had only a weak correlation. CONCLUSION:This study has demonstrated a moderate to strong correlation of regional CMR measurements to corresponding echocardiographic measures. However, biases and to some extent wide limits of agreement, exist between the modalities. Consequently, the equivalent measures are not interchangeable at least in patients with pulmonary hypertension. The echocardiographic parameter that showed best correlation with RVEFCMR was FWSecho. At present, FACecho and FWSecho as well as RVEFCMR are the preferred methods to assess and follow up RV function in patients with pulmonary hypertension. Future investigations of the CMR right ventricular measures, beyond RVEF, are warranted.
Project description:Hypertension is associated with microvascular and macrovascular brain injury but its direct influence on the cerebral circulation is not fully clear. Our objective was to investigate the association of hypertension with global and regional cerebral vasoreactivity to CO(2) using continuous arterial spin labeling MRI, independent of stroke and white matter hyperintensities. Participants (n=62; mean age: 66.7±1.0 years, 55% women, 84% white, 65% hypertension, 47% stroke) underwent arterial spin labeling perfusion MRI during normal breathing, 5% CO(2) rebreathing, and hyperventilation, as well as 24-hour ambulatory blood pressure monitoring. Vasoreactivity was the slope of the regression between cerebral perfusion and end-tidal CO(2). White matter hyperintensity volumes were quantified. Nighttime dipping was calculated as the percentage decline in nighttime/daytime blood pressure. After accounting for stroke and white matter hyperintensity volume, hypertensive participants had lower global vasoreactivity (1.11±0.13 versus 0.43±0.1 mL/100 g per minute per millimeter of mercury; P=0.0012). Regionally, this was significant in the frontal, temporal, and parietal lobes. Higher mean systolic blood pressure was associated with lower vasoreactivity (decreased by 0.11 U/10-mm Hg increase in systolic blood pressure; P=0.04), but nighttime dipping was not (P=0.2). The magnitude of decrease in vasoreactivity in hypertension without stroke was comparable to the magnitude of decrease in vasoreactivity in stroke without hypertension. Hypertension has a direct negative effect on the cerebrovascular circulation independent of white matter hyperintensities and stroke that is comparable to that seen with stroke. Because lower vasoreactivity is associated with poor outcomes, studies of the impact of antihypertensive on vasoreactivity are important.
Project description:Pulmonary arterial hypertension (PAH) remains a severe clinical condition despite the availability over the past 15?years of multiple drugs interfering with the endothelin, nitric oxide and prostacyclin pathways. The recent progress observed in medical therapy of PAH is not, therefore, related to the discovery of new pathways, but to the development of new strategies for combination therapy and on escalation of treatments based on systematic assessment of clinical response. The current treatment strategy is based on the severity of the newly diagnosed PAH patient as assessed by a multiparametric risk stratification approach. Clinical, exercise, right ventricular function and haemodynamic parameters are combined to define a low-, intermediate- or high-risk status according to the expected 1-year mortality. The current treatment algorithm provides the most appropriate initial strategy, including monotherapy, or double or triple combination therapy. Further treatment escalation is required in case low-risk status is not achieved in planned follow-up assessments. Lung transplantation may be required in most advanced cases on maximal medical therapy.