Association between aortic knob width and invasively measured aortic pulse pressure

BACKGROUND Aortic knob width (AKW), which can be measured easily in simple radiography, is associated with the degree of dilatation and tortuosity of the aortic arch. Pulsatile stress influences aortic geometry. This study was carried out to investigate whether AKW can represent invasively measured aortic pulse pressure (APP). METHODS A total of 252 patients who underwent invasive coronary angiography (ICA) for the evaluation of coronary artery disease were enrolled. AKW was defined as the perpendicular length from the lateral margin of the main bronchus to the most prominent edge of the aortic knob on chest radiography. APP was measured at the ascending aorta using a pigtail catheter immediately before ICA. RESULTS When patients were divided into two groups according to the median value of APP (69 mmHg), AKW was significantly greater in patients with higher APP (≥69 mmHg) than in those with lower APP (