- Oral presentation
- Open Access
Quantification of pulmonary edema in heart failure using MRI: invasive validation and evaluation in HFpEF and HFrEF patients
© Thompson et al. 2016
- Published: 27 January 2016
- Heart Failure Patient
- Filling Pressure
- Water Density
- NYHA Class
- Diagnostic Cardiac Catheterization
Pulmonary edema is a cardinal feature of heart failure (HF), reflecting impaired ventricular filling. The associated increase in left ventricular end-diastolic pressure (LVEDP) results in accumulation of fluid in the interstitium/alveolae. MRI signal is directly proportional to water density (WD) and is thus an attractive tool for quantitative assessment of edema. The primary goals of the current study were to: (1) evaluate the relationship between MRI-derived lung WD and invasively measured LVEDP in patients with HF and (2) characterize lung WD in healthy controls, patients at risk for HF and HF patients with NYHA class I-III symptoms.
Consecutive patients with HF referred for a diagnostic cardiac catheterization (LVEDP or wedge pressure measured) were screened for enrollment in the validation arm of the study (19 patients recruited). Patients underwent MRI within 2 hrs of catheterization for comparison of MRI-derived lung WD and filling pressures. 226 additional subjects from the Alberta HEART study (BMC Cardiovasc Disord. 2014 Jul 25;14:91) included: healthy controls N = 56, at-risk for HF N = 58, HF with preserved LVEF (HFpEF) N = 64 and reduced LVEF (HFrEF) (< 50%) N = 48, who were evaluated with the same lung water imaging protocol.
Imaging was performed on a Siemens Sonata 1.5T (Siemens Healthcare, Erlangen, Germany). Lung water was measured using a half-Fourier single-shot turbo spin echo (HASTE) pulse sequence. 128 × 66 matrix, 8 mm slice, 4/8 ths partial Fourier, 780 Hz/pixel bandwidth, 12 ms TE, image acquisition during diastasis, body coil excite/receive. Lung image signal intensities from a single sagittal slice in the right lung were normalized to units of water density using a liver region as a reference signal (70% liver WD assumed, J Appl Physiol. 1959;14:1005-8).
Increased lung WD is significantly associated with increased filling pressures in HF patients, and WD can be estimated as part of a standard clinical CMR exam. Increased lung water is associated with worsening NYHA Class, independent of LVEF.
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