Validation of CMR Against Invasive Haemodynamics in Patients With HFpEF

Cardiovascular magnetic resonance (CMR) provides non-invasive, radiation-free and in-depth evaluation of myocardial structure and function. In addition to established tools for assessment of cardiac volume, mass, function and regional myocardial scar with late Gadolinium enhancement (LGE), several novel quantitative CMR parameters will be assessed including T1-mapping or fully quantitative perfusion Imaging.

Blood samples will eventually be analysed for markers related to heart failure (BNP/NT)-pro-BNP, myocardial inflammation and fibrosis (cytokine profiling, Galectin-3, Procollagen Type I and III, hsCRP). Whole blood will be frozen for DNA isolation and genome analysis. Peripheral blood mononuclear cells will be isolated by Ficoll in a subset of patients and will be used for RNA isolation allowing RNA-seq or reverse transcription (RT) - polymerase chain reaction (PCR) analysis.

Measurements will include cavity dimensions, flow velocities, myocardial motion velocity and strain as well as for change of parameters during ergometric stress.

Multiple parameters (including EDPVR, ESPVR, dp/dt min, Tau, Ea) will be derived from the various PV loop assessments and additional relevant parameters will be calculated. Right ventricular and pulmonary pressures including pulmonary vascular resistance will be measured with Swan-Ganz catheters using right venous femoral approach.

"A set of myocardial biopsies for each patient will be stained with Masson Trichrome for qualitative and quantitative assessment of the collagen volume fraction; fat droplets will be identified by red oil staining, Congo Red for amyloid immunohistology will be used to determine total leukocytes (CD45), T-cells (CD3) and monocytes/macrophages (CD68).~A second set of biopsies will be frozen immediately and stored at -80°. Western blot analysis will be performed to determine alterations at the myofilament level including titin isoform composition and phosphorylation status."