High-resolution echocardiography and MRI accurately determined pulmonary hemodynamics and right ventricular mass, offering similar results to high-fidelity catheterization in a rat model of PAH.
Do high-resolution echocardiography and MRI accurately estimate pulmonary artery pressure, cardiac output, and right ventricular mass compared to invasive catheterization in a rat model of pulmonary hypertension?
High-resolution echocardiography and MRI provide accurate, noninvasive assessments of pulmonary hemodynamics and right ventricular remodeling in experimental rat models of pulmonary hypertension.
Effect estimate: r2 = 0.68
p-value: p=<0.001
High-frequency echocardiography and high-field-strength magnetic resonance imaging (MRI) are new noninvasive methods for quantifying pulmonary arterial hypertension (PAH) and right ventricular (RV) hypertrophy (RVH). We compared these noninvasive methods of assessing the pulmonary circulation to the gold standard, cardiac catheterization (micromanometer-tipped catheters), in rats with monocrotaline-induced PAH and normal controls. Closed-chest, Sprague-Dawley rats were anesthetized with inhaled isoflurane (25 monocrotaline, 6 age-matched controls). Noninvasive studies used 37.5-MHz ultrasound (Vevo 770; VisualSonics) or a 9.4-T MRI (Bruker BioSpin). Catheterization used a 1.4-F micromanometer-tipped Millar catheter and a thermodilution catheter to measure cardiac output (CO). We compared noninvasive measures of pulmonary artery (PA) pressure (PAP) using PA acceleration time (PAAT) and CO, using the geometric PA flow method and RV free wall (RVFW) thickness/mass with cardiac catheterization and/or autopsy. Blinded operators performed comparisons using each method within 2 days of another. In a subset of rats with monocrotaline PAH, weekly echocardiograms, catheterization, and autopsy data assessed disease progression. Heart rate was similar during all studies (>323 beats/min). PAAT shortened, and the PA flow envelope displayed systolic "notching," reflective of downstream vascular remodeling/stiffening, within 3 wk of monocrotaline. MRI and echocardiography measures of PAAT were highly correlated (r(2) = 0.87) and were inversely proportional to invasive mean PAP (r(2) = 0.72). Mean PAP by echocardiography was estimated as 58.7 - (1.21 x PAAT). Invasive and noninvasive CO measurement correlated well (r(2) >or= 0.75). Noninvasive measures of RVFW thickness/mass correlated well with postmortem measurements. We conclude that high-resolution echocardiography and MRI accurately determine CO, PAP, and RV thickness/mass, offering similar results as high-fidelity right heart catheterization and autopsy, and that PAAT accurately estimates PAP and permits serial monitoring of experimental PAH. These tools are useful for assessment of the rodent pulmonary circulation and RVH.
Urboniene et al. (Sat,) conducted a other in Experimental pulmonary arterial hypertension (n=31). High-resolution echocardiography and MRI vs. High-fidelity right heart catheterization and autopsy was evaluated on Correlation between pulmonary artery acceleration time (PAAT) measured by echocardiography and invasive mean pulmonary artery pressure (mPAP) (r2 = 0.68, p=<0.001). High-resolution echocardiography and MRI accurately determined pulmonary hemodynamics and right ventricular mass, offering similar results to high-fidelity catheterization in a rat model of PAH.