Native myocardial T1 correlates with right ventricular remodelling in patients with pulmonary hypertension

Introduction: T1 elevation has been observed in the right ventricular (RV) insertion points of pulmonary hypertension (PH) patients and animal models (Spruijt, O., et al., JCMR, 2015; 17(1): 44; Garcia-Alvarez, A., et al., JACC, 2015. 8(1):76-82) however the association with cardiac remodelling and function metrics in patients with PH is incompletely understood. Objective: To characterise native myocardial T1 values in patients with PH in comparison to right ventricular function and remodelling. Method: 204 patients with suspected PH (59±17 years, 56% F) and 34 healthy volunteers (50±15 years, 50% F) underwent MRI at 1.5T, including a Modified Look Locker Inversion Recovery T1 mapping sequence. 142/204 patients had a diagnosis of PH and PCWP Results: Patients with PH had elevated myocardial T1 values compared to healthy volunteers (superior RV insertion point: p=0.004; inferior RV insertion point: p=0.005). Within patients with PH, systolic septal angle correlated positively with RV insertion point T1 (superior: r= 0.258, p=0.003; inferior: r=0.291, p=0.021) and septal T1 (r=0.188, p=0.031). RV insertion point T1 correlated with RV mass index (superior: r=0.293 p=0.001; inferior: r=0.173, p=0.043). Conclusion: T1 elevation correlates with a larger RV mass and a greater septal angle in patients with PH.