Hemodynamic Effects of Monomeric Nonionic Contrast Media in Pulmonary Angiography in Chronic Thromboembolic Pulmonary Hypertension

Abstract

The purpose of this study was to investigate the hemodynamic safety of the monomeric nonionic contrast agent iomeprol for selective pulmonary angiography in chronic thromboembolic pulmonary hypertension (CTPH), and to investigate the effect of periinterventional oxygen administration. Selective pulmonary digital subtraction angiography was performed in 94 patients with CTPH using six bolus injections of iomeprol (posteroanterior, oblique, and lateral projections; both pulmonary arteries; iomeprol, 25 mL at 13 mL/s). Hemodynamics were obtained with Swan-Ganz catheters, and systolic pulmonary artery pressure (PAsyst) was classified into one of three groups: 30 mm Hg or less (control group), greater than 30 but less than or equal to 60 mm Hg (group 1, moderate pulmonary hypertension), and greater than 60 mm Hg (group 2, severe pulmonary hypertension). At baseline, values for PAsyst were 21.4 +/- 2.3 (control group, n = 8), 49.8+/- 8.5 (group 1, n = 18), and 86.5 +/- 18.9 (group 2, n = 68) mm Hg (p < 0.001). Pulmonary vascular resistance indexes (PVRI) were 222 +/- 105 (control), 703 +/- 364 (group 1), and 1,582 +/- 562 (group 2) dyne x s x cm(-5) x m2 (p < 0.001). The mean cardiac indexes were 3.1 (control), 2.8 (group 1), and 2.3 (group 2) L/min/m2 (p < 0.05). Pulmonary capillary wedge pressure (PCw) indicated healthy left heart function. Periinterventional oxygen inhalation improved oxygen saturation in all groups and slightly reduced pulmonary artery pressure and heart rate. Online measurement of pulmonary artery pressure during contrast bolus injection for angiography showed only a minor increase, predominantly in severe pulmonary hypertension (triangle up [difference] PAsyst: 1.3 +/- 1.9 [control], 2.9 +/- 3.4 [group 1], and 3.8 +/- 4.5 [group 2] mm Hg [p < 0.001]). After completion of angiography, right atrial pressure (RAP) and PAsyst were moderately increased: triangle up RAP: 1.4 (control), 2.6 (group 1, p < 0.001), and 3.0 (group 2, p < 0.001) mm Hg; triangle up PAsyst: 3.2 (control), 7.7 (group 1, p < 0.01), and 8.5 (group 2) mm Hg (p < 0.001). PVRI was significantly higher in group 2 (triangle up PVRI: 188 dyne x s x cm(-5) x m2, p < 0.001). Selective pulmonary angiography using iomeprol is safe without critical pressure peaks during selective contrast bolus injection or significant hemodynamic derangement in severe CTPH. Periinterventional oxygen inhalation improved pulmonary circulation.