Page 44 - Assessing right ventricular function and the pulmonary circulation in pulmonary hypertension Onno Anthonius Spruijt

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heart failure, and significant parenchymal lung disease. Patients recruited at the VU University Medical Center had a diagnosis of idiopathic or familial PAH and underwent cardiac magnetic resonance (CMR) as part of a prospective study to evaluate the role of CMR in the management of PAH, for which medical ethical consent approval was obtained.
The composite endpoint of the study was death or lung transplantation. Death was verified through the national Social Security Death Index and transplantation through chart review. Data collection included demographics, 6-min walking distance (6MWD), estimated glomerular filtration rate, N- terminal pro–B-type natriuretic peptide (NTproBNP) levels, diffusion capacity of carbon monoxide, and hemodynamics. Renal function was estimated using the modified diet and renal equation [10]. For purposes of standardization, data were collected on the first outpatient visit after stabilization on disease-modifying medications (prostanoids, endothelin receptor blockers, or phosphodiesterase inhibitors). We chose this time point for 2 reasons. First, this time point corresponded to the same day patients completed echocardiography, 6MWD, and laboratory testing (metabolic panel and NT- proBNP). In addition, the baseline right heart catheterization was often obtained within a 3- to 6- month time frame of this visit.
Echocardiography
Digitized echocardiographic studies were analyzed by the Stanford Cardiovascular Institute biomarker and phenotypic core laboratory in accordance with published guidelines of the American Society of Echocardiography (ASE) [11]. All measures were averaged over 3 cycles, and RV or RA size measures were indexed to body surface area. RV end-diastolic and end-systolic areas, as well as RA size, were measured from the apical 4-chamber view (Figure 1). RV function was quantified using right ventricular fractional area change (RVFAC), tricuspid annular systolic excursion (TAPSE), and right ventricular myocardial performance index (RVMPI), as previously described [11-13]. RA size was measured at end-systole (RAmax), pre-atrial contraction (RApre-A), and end-diastole (RAmin) (Figure 2), and total, passive, and active RAEF were calculated as follows:
RAEFtotal = (RAmax - RAmin) / RAmax RAEFpassive = (RAmax - RApre-A) / RAmax RAEFactive = (RApre-A - RAmin) / RApre-A