Prognostic value of late gadolinium enhancement mass index in patients with pulmonary arterial hypertension

Abstract

Purpose: Dysfunction of the right ventricle (RV) is an important determinant of survival in patients with pulmonary arterial hypertension (PAH). The presence of late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) at RV insertion points (RVIPs) has been found in majority of PAH patients and was associated with parameters of RV dysfunction. We hypothesize, that more detailed quantification of LGE may provide additional prognostic information.

Material and methods: Twenty-eight stable PAH patients (mean age 49.9 ​± ​15.9 years) and 12 healthy subjects (control group, 44.8 ​± ​13.5 years) were enrolled into the study. Septal LGE mass was quantified at the RVIPs and subsequently indexed by subject's body surface area. Mean follow-up time of this study was 16.6 ​± ​7.5 months and the clinical end-point (CEP) was defined as death or clinical deterioration.

Results: Median LGE mass index (LGEMI) at the RVIPs was 2.75 ​g/m2 [1.41-4.85]. We observed statistically significant correlations between LGEMI and hemodynamic parameters obtained from right heart catheterization - mPAP (r ​= ​0.61, p ​= ​0.001); PVR (r ​= ​0.52, p ​= ​0.007) and from CMR - RVEF (r ​= ​-0.54, p ​= ​0.005); RV global longitudinal strain (r ​= ​0.42, p ​= ​0.03). Patients who had CEP (n ​= ​16) had a significantly higher LGEMI (4.49 [2.75-6.17] vs 1.67 [0.74-2.7], p ​= ​0.01); univariate Cox analysis confirmed prognostic value of LGEMI. Furthermore, PAH patients with LGEMI higher than median had worse prognosis in Kaplan-Meier analysis (log-rank test, p ​= ​0.0006).

Conclusions: The body surface indexed mass of LGE at RV septal insertion points are suggestive of RV hemodynamic dysfunction and could be a useful non-invasive marker of PAH prognosis.

Keywords: Catheterization; Gadolinium; Magnetic resonance imaging; Prognosis; Pulmonary hypertension.