Evaluation Of Myocardial Damage In Patients With Pulmonary Hypertension By Myocardial Delayed Contrast Enhancement MR Imaging And Its Impact On Cardiac Function

Objective To assess the extent of myocardial damage and its impact on cardiac function in patients with pulmonary hypertension(PH) using myocardial delayed contrast enhancement(DCE) MR imaging.Materials and Methods Sixty patients with PH were confirmed by right heart catheterization(RHC). All patients underwent MR imaging, 8 males and 52 females, aged(39.9±12.5)years. Right ventricle(RV) and left ventricle(LV) end-diastolic and end-systolic volumes(EDV & ESV), ejection fraction(EF), stroke volume(SV), mass, fractional distance change from septum to free-wall(fractional-SFD), fractional tricuspid annulus apex distance change(fractional-TAAD), curvature of interventricular septum(CIVS), and curvature ratio(RC) were obtained by steady-state free precession sequence(FIESTA) images. EDV, ESV, SV, MM were corrected for body surface area(BSA). Ventricular mass index(VMI) was determined as RVMM/LVMM. DCE images were post-processed for calculating DCE MM. Location and characteristics of myocardial DCE were also observed and analyzed. Independent Sample t-Test or Mann-Whitney U Test was used to compare the differences of ventricular function parameters in PH patients with and without DCE.Results DCE was present in 49 patients(81.67%). DCE was confined to the RV insertion points(RVIPs) in 12 patients(24.49%), and extended into the interventricular septum(IVS) in 37 patients(75.51%). DCE was present both anterior and inferior in 43 patients(87.76%). Myocardium DCE tends to occur in the base and middle parts of RV. The base part of the RV involved were in 49 cases(93.88%), the middle part of the RV involved were in 45 cases(91.84%), while only in 19 patients,DCE was present in the apex part of the RV(38.78%).In addition, when DCE was present in the apex, the middle and the base parts were usually involved. All DCE was limited to the mid-wall region of the ventricular myocardium. DCE MM was(3.83±1.93)g, 2.88%(0.25%-6.50%)of the total mass of both RV and LV. For patients with DCE, RV ESVI and VMI were significantly increased(P=0.040, 0.011), while RV EF, fractional-TAAD, CIVS and RC was significantly decreased(P=0.002, 0.001, 0.023, 0.001).Conclusions Myocardial DCE can be used as a reference to evaluate the severity of cardiac function damage in patients with PH.