Randomized, Double-Blind Study Comparing Patient Comfort and Safety Between Iodixanol 320 mg I/mL and Iopamidol 370 mg I/mL in Patients Undergoing Peripheral Arteriography - The COMFORT II Trial.

Numerous clinical trials conducted 10-20 years ago evaluated contrast-induced discomfort. It is unknown whether those data are applicable to current-day clinical practice. This study was performed to provide contemporary contrast-induced patient discomfort data obtained during peripheral arteriography procedures using iso-osmolar iodixanol 320 mg I/mL, compared to low-osmolar iopamidol 370 mg I/mL.Patients receiving iodixanol or iopamidol reported discomfort (heat, coldness, or pain) using a 10-point scale, which was converted to intensity categories: 0 = none; 1-3 = mild; 4-7 = moderate; and 8-10 = severe. Image diagnostic quality was assessed. Patients receiving iodixanol (n = 127; 61% male; mean age, 64 years) had less moderate/severe discomfort (67.7% vs 84.0%; P=.01) than those receiving iopamidol (n = 126; 64% male; mean age, 62 years), with pain contributing predominantly (7.3% vs 44.0%; P<.001) for all injection scores. Patients receiving iodixanol experienced less severe discomfort (16.9% vs 46.4%; P<.001), heat (15.3% vs 36.8%; P<.001), and pain (2.4% vs 23.2%; P<.001) for all injections, compared with patients receiving iopamidol. Image quality was rated as excellent in most patients (iodixanol 86.5% vs iopamidol 82.4%; P=.57). Treatment-emergent adverse events were similar between groups (iodixanol 18.9% vs iopamidol 11.9%; P=.16).Iodixanol injections induced significantly less moderate/severe and severe patient discomfort, heat, or pain than iopamidol, with pain contributing the most. Discomfort did not affect image quality.