title: The importance of trabecular hypertrophy in right ventricular adaptation to chronic pressure overload.
abstract: To assess the contribution of right ventricular (RV) trabeculae and papillary muscles (TPM) to RV mass and volumes in controls and patients with pulmonary arterial hypertension (PAH). Furthermore, to evaluate whether TPM shows a similar response as the RV free wall (RVFW) to changes in pulmonary artery pressure (PAP) during follow-up. 50 patients underwent cardiac magnetic resonance (CMR) and right heart catheterization at baseline and after one-year follow-up. Furthermore 20 controls underwent CMR. RV masses were assessed with and without TPM. TPM constituted a larger proportion of total RV mass and RV end-diastolic volume (RVEDV) in PAH than in controls (Mass: 35 ± 7 vs. 25 ± 5 %; p < 0.001; RVEDV: 17 ± 6 vs. 12 ± 6 %; p = 0.003). TPM mass was related to the RVFW mass in patients (baseline: R = 0.65; p < 0.001; follow-up: R = 0.80; p < 0.001) and controls (R = 0.76; p < 0.001). In PAH and controls, exclusion of TPM from the assessment resulted in altered RV mass, volumes and function than when included (all p < 0.01). Changes in RV TPM mass (β = 0.44; p = 0.004) but not the changes in RVFW mass (p = 0.095) were independently related to changes in PAP during follow-up. RV TPM showed a larger contribution to total RV mass in PAH (~35 %) compared to controls (~25 %). Inclusion of TPM in the analyses significantly influenced the magnitude of the RV volumes and mass. Furthermore, TPM mass was stronger related to changes in PAP than RVFW mass. Our results implicate that TPM are important contributors to RV adaptation during pressure overload and cannot be neglected from the RV assessment.
authors.affiliation: Department of Pulmonary Diseases, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands, m.vandeveerdonk@vumc.nl.
authors.forename: Mariëlle C
authors.initials: MC
authors.lastname: van de Veerdonk
authors.forename: Sophie A
authors.initials: SA
authors.lastname: Dusoswa
authors.forename: J Tim
authors.initials: JT
authors.lastname: Marcus
authors.forename: Harm-Jan
authors.initials: HJ
authors.lastname: Bogaard
authors.forename: Onno
authors.initials: O
authors.lastname: Spruijt
authors.forename: Taco
authors.initials: T
authors.lastname: Kind
authors.forename: Nico
authors.initials: N
authors.lastname: Westerhof
authors.forename: Anton
authors.initials: A
authors.lastname: Vonk-Noordegraaf
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D000368:Aged; D062186:Arterial Pressure; D006328:Cardiac Catheterization; D065627:Familial Primary Pulmonary Hypertension; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D017380:Hypertrophy, Right Ventricular / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D010210:Papillary Muscles / Q000473:pathology* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011651:Pulmonary Artery / Q000503:physiopathology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013997:Time Factors; D016278:Ventricular Function, Right; D020257:Ventricular Remodeling