Objectives: The aim of this study was to assess native T1 mapping in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) before and 6 months after balloon pulmonary angioplasty (BPA) and compare the results with right heart function and pulmonary haemodynamics.
Methods: Magnetic resonance imaging at 1.5 T and right heart catheterisation were performed in 21 consecutive inoperable CTEPH patients before and 6 months after BPA. T1 values were measured within the septal myocardium, the upper and lower right ventricular insertion points, and the lateral wall at the basal short-axis section. In addition, the area-adjusted septal native T1 time (AA-T1) was calculated and compared with right ventricular function (RVEF), mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR).
Results: The mean AA-T1 value decreased significantly after BPA (1,045.8 ± 44.3 ms to 1,012.5 ± 50.4 ms; p < 0.001). Before BPA, native T1 values showed a moderate negative correlation with RVEF (r = -0.61; p = 0.0036) and moderate positive correlations with mPAP (r = 0.59; p < 0.01) and PVR (r = 0.53; p < 0.05); after BPA correlation trends were present (r = -0.21, r = 0.30 and r = 0.35, respectively).
Conclusions: Native T1 values in patients with inoperable CTEPH were significantly lower after BPA and showed significant correlations with RVEF and pulmonary haemodynamics before BPA. Native T1 mapping seems to be indicative of reverse myocardial tissue remodelling after BPA and might therefore have good potential for pre-procedural patient selection, non-invasive therapy monitoring and establishing a prognosis.
Key points: • BPA is a promising treatment option for patients with inoperable CTEPH • Native septal T1 values significantly decrease after BPA and show good correlations with right ventricular function and haemodynamics before BPA • Prognosis and non-invasive therapy monitoring might be supported in the future by native T1 mapping.
Keywords: Angioplasty; Magnetic resonance imaging; Pulmonary embolism; Pulmonary hypertension.