Non-invasive estimation of pulmonary vascular resistance with cardiac magnetic resonance

García‐Álvarez, Ana; Fernández‐Friera, Leticia; Mirelis, J. González; Sawit, Simonette T; Nair, Ajith; Kallman, Jill; Fuster, Valentín; Sanz, Javier

doi:10.1093/eurheartj/ehr173

Cited by 81 publications

(89 citation statements)

References 30 publications

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“…The linearity of the RVEF-R relationship for RVEF >35% is consistent with the linear relationship observed in mild and moderate PAH. 11 Similar to the linear-R model, the mixed linear model is consistent with the curvilinear RVEF-C relationship observed by Stevens et al 18 In Table 1, we summarize strengths and weaknesses of the three models on the basis of clinical evidence. In Figure 2, we directly compare the results from our models with the empirical correlations derived from the limited clinical data available.…”

Section: Methodssupporting

confidence: 69%

What Does the Time Constant of the Pulmonary Circulation Tell us about the Progression of Right Ventricular Dysfunction in Pulmonary Arterial Hypertension?

2015

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Compliance (C ) and resistance (R ) maintain a unique, inverse relationship in the pulmonary circulation, resulting in a constant characteristic time τ ¼ RC that has been observed in healthy subjects as well as patients with pulmonary arterial hypertension (PAH). However, little is known about the dependence of right ventricular (RV) function on the coupled changes in R and C in the context of this inverse relationship. We hypothesized three simple dependencies of RV ejection fraction (RVEF) on R and C. The first model (linear-R ) assumes a linear RVEF-R relation; the second (linear-C ) assumes a linear RVEF-C relation; and the third one combines the former two in a mixed linear model. We found that the linear-R model and the mixed linear model are in good agreement with clinical evidence. A conclusive validation of these models will require more clinical data. Longitudinal data in particular are needed to identify the time course of ventricular-vascular impairment in PAH. Simple models like the ones we present here, once validated, will advance our understanding of the mechanisms of RV failure, which could improve strategies to manage RV dysfunction in PAH. In understanding the progression of right ventricular (RV) failure in pulmonary arterial hypertension (PAH), a key knowledge gap is the mechanisms that underlie the transition from normal RV function to RV dysfunction and failure and how these transitions are dependent on changes in pulmonary vascular function as the disease progresses. Clinical studies have shown that the mechanical properties of the pulmonary vasculature (i.e., resistance [R] and compliance [C ]) correlate with mortality in PAH. [1][2][3] In addition, an inverse relationship exists between C and R in the pulmonary circulation. 4 The time constant τ ¼ RC has been found to be equal to ∼0.5 s in a large clinical population, including patients with and without PAH, patients with different types of PAH, and patients before and after treatment. 4-7 However, it is unclear how pathological changes in vascular R and C mediate RV dysfunction.Here we formulate three hypothetical models to describe the dependence of RV function on the metrics of pulmonary vascular function R and C. We hypothesize that RV function, expressed as RV ejection fraction (RVEF), depends linearly on R or C or on a combination of both. The results from the three models are evaluated on the basis of relevant clinical evidence. METHODSTo describe the dependence of RV function on R and C, we chose a single metric of RV function. Under normal physiological conditions, known mechanisms of RV autoregulation preserve stroke volume (SV ) and cardiac output (CO) in the face of increased afterload. 8 The maintenance of SV or CO may persist in the adaptively functioning RV in mild or moderate PAH; thus, it would be difficult to correlate these parameters with the early phase of disease. RVEF may be a more sensitive metric of PAH progression than SV and CO. 9 RVEF correlates with mean pulmonary artery pressure 10 and pulmonary...

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Section: Methodssupporting

confidence: 69%

What Does the Time Constant of the Pulmonary Circulation Tell us about the Progression of Right Ventricular Dysfunction in Pulmonary Arterial Hypertension?

2015

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“…23 Thus, an alternative approach is desirable, and several adult CMR studies have shown that septal curvature correlates well with pulmonary artery pressure. 2,5,6,8,9,[24][25][26][27] However, this is the first pediatric CMR study to investigate the relationship between septal curvature and pulmonary hemodynamics. Furthermore, it is the first study to compare septal curvature with simultaneously acquired pulmonary hemodynamic data.…”

Section: Discussionmentioning

confidence: 99%

Real-Time Magnetic Resonance Assessment of Septal Curvature Accurately Tracks Acute Hemodynamic Changes in Pediatric Pulmonary Hypertension

Pandya

Quail

Steeden

et al. 2014

Circ: Cardiovascular Imaging

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Background-This study assesses the relationship between septal curvature and mean pulmonary artery pressure and indexed pulmonary vascular resistance in children with pulmonary hypertension. We hypothesized that septal curvature could be used to estimate right ventricular afterload and track acute changes in pulmonary hemodynamics. Methods and Results-Fifty patients with a median age of 6.7 years (range, 0.45-16.5 years) underwent combined cardiac catheterization and cardiovascular magnetic resonance. The majority had idiopathic pulmonary arterial hypertension (n=30); the remaining patients had pulmonary hypertension associated with repaired congenital heart disease (n=17) or lung disease (n=3). Mean pulmonary artery pressure and pulmonary vascular resistance were acquired at baseline and during vasodilation. Septal curvature was measured using real-time cardiovascular magnetic resonance. There was a strong correlation between mean pulmonary artery pressure and SC min at baseline and during vasodilator testing (r=-0.81 and -0.85, respectively; P<0.01). A strong linear relationship also existed between pulmonary vascular resistance and minimum septal curvature indexed to cardiac output both at baseline and during vasodilator testing (r=-0.88 and -0.87, respectively; P<0.01). Change in septal curvature metrics moderately correlated with absolute change in mean pulmonary artery pressure and pulmonary vascular resistance, respectively (r=0.58 and -0.74; P<0.01). Septal curvature metrics were able to identify vasoresponders with a sensitivity of 83% (95% confidence interval, 0.36-0.99) and a specificity of 91% (95% confidence interval, 0.77-0.97), using the Sitbon criteria. Idiopathic pulmonary arterial hypertension subgroup analysis revealed 3 responders with ΔSC min values of 0.523, 0.551, and 0.568. If the middle value of 0.551 is taken as a cutoff, the approximate sensitivity would be 67% and the specificity would be 93%. Conclusions-Septal curvature metrics are able to estimate right ventricular afterload and track acute changes in pulmonary hemodynamics during vasodilator testing. This suggests that septal curvature could be used for continuing assessment of load in pulmonary hypertension. (Circ Cardiovasc Imaging. 2014;7:706-713.)

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“…PVR was finally calculated by subtraction of calculated PCWP from calculated mPAP divided by cardiac output as determined by phase-contrast imaging in the pulmonary artery. For estimated PVR, the authors found limits of agreement ranging between -5.1 and + 4.6 wood units, which were slightly narrower than those of the validation group in the study of Garcia-Alvarez et al [52,53]. Kreitner et al used a phase-contrast sequence with high temporal resolution in the main pulmonary artery for the assessment of hemodynamics in patients with CTEPH.…”

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confidence: 96%

“…Actually, there are three published MR-based approaches for noninvasive assessment of mPAP and/or PVR ( • " Table 1). Garcia-Alvarez et al presented an MR-based method for the assessment of pulmonary vascular resistance using a derivation and validation cohort with different forms of pulmonary hypertension [52]. Their statistical model is based on standard cine and phase-contrast sequences.…”

mentioning

confidence: 99%

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) – Potential Role of Multidetector-Row CT (MD-CT) and MR Imaging in the Diagnosis and Differential Diagnosis of the Disease

Wirth

Brüggemann

Bostel

et al. 2014

Fortschr Röntgenstr

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Chronic thromboembolic pulmonary hypertension (CTEPH) can be defined as pulmonary hypertension (resting mean pulmonary arterial pressure of 25?mm Hg or more determined at right heart catheterization) with persistent pulmonary perfusion defects. It is a rare, but underdiagnosed disease with estimated incidences ranging from 0.5?% to 3.8?% of patients after an acute pulmonary embolism (PE), and in up to 10?% of those with a history of recurrent PE. CTEPH is the only form of pulmonary hypertension that can be surgically treated leading to normalization of pulmonary hemodynamics and exercise capacity in the vast majority of patients. The challenges for imaging in patients with suspected CTEPH are fourfold: the imaging modality should have a high diagnostic accuracy with regard to the presence of CTEPH and allow for differential diagnosis. It should enable detection of patients suitable for PEA with great certainty, and allow for quantification of PH by measuring pulmonary hemodynamics (mPAP and PVR), and finally, it can be used for therapy monitoring. This overview tries to elucidate the potential role of ECG-gated multidetector CT pulmonary angiography (MD-CTPA) and MR imaging, and summarizes the most important results that have been achieved so far. Generally speaking, ECG-gated MD-CTPA is superior to MR in the assessment of parenchymal and vascular pathologies of the lung, and allows for the assessment of cardiac structures. The implementation of iodine maps as a surrogate for lung perfusion enables functional assessment of lung perfusion by CT. MR imaging is the reference standard for the assessment of right heart function and lung perfusion, the latter delineating typical wedge-shaped perfusion defects in patients with CTEPH. New developments show that with MR techniques, an estimation of hemodynamic parameters like mean pulmonary arterial pressure and pulmonary vascular resistance will be possible. CT and MR imaging should be considered as complementary investigations providing comprehensive information in patients with CTEPH. Citation Format: ??Wirth G, Br?ggemann K, Bostel T et?al. Chronic Thromboembolic Pulmonary Hypertension (CTEPH) ? Potential Role of Multidetector-Row CT (MD-CT) and MR Imaging in the Diagnosis and Differential Diagnosis of the Disease. Fortschr R?ntgenstr 2014; 186: 751???761

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Non-invasive estimation of pulmonary vascular resistance with cardiac magnetic resonance

Cited by 81 publications

References 30 publications

What Does the Time Constant of the Pulmonary Circulation Tell us about the Progression of Right Ventricular Dysfunction in Pulmonary Arterial Hypertension?

What Does the Time Constant of the Pulmonary Circulation Tell us about the Progression of Right Ventricular Dysfunction in Pulmonary Arterial Hypertension?

Real-Time Magnetic Resonance Assessment of Septal Curvature Accurately Tracks Acute Hemodynamic Changes in Pediatric Pulmonary Hypertension

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) – Potential Role of Multidetector-Row CT (MD-CT) and MR Imaging in the Diagnosis and Differential Diagnosis of the Disease

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