Dynamic chest radiography as a novel minimally invasive hemodynamic imaging method in patients with heart failure

Purpose: Dynamic chest radiography allows for non-invasive cardiopulmonary blood flow assessment. However, data on its use for heart failure hemodynamic assessment are scarce. We utilized dynamic chest radiography to estimate heart failure hemodynamics. Method: Twenty heart failure patients (median age, 67 years; 17 men) underwent dynamic chest radiography and right heart catheterization. The analyzed images were 16-bit images (grayscale range: 0-65,535). Right atrial, right pulmonary artery, and left ventricular apex pixel values (average of the grayscale values of all pixels within a region of interest) were measured. The correlations of the minimum, maximum, mean, amount of change, and rate of change in pixel values with right atrial pressure, pulmonary artery pressure, pulmonary artery wedge pressure, and cardiac index were analyzed.Results: The mean right atrial pixel value and mean right atrial pressure (R =-0.576, P = 0.008), mean right pulmonary artery pixel value and mean pulmonary artery pressure (R =-0.546, P = 0.013), and left ventricular apex pixel value change rate and mean pulmonary artery wedge pressure (R =-0.664, P = 0.001) or cardiac index (R = 0.606, P = 0.005) were correlated. The left ventricular apex pixel value change rate identified low cardiac index (area under the curve, 0.792; 95% confidence interval, 0.590-0.993; P = 0.031) and low cardiac index with high pulmonary artery wedge pressure (area under the curve, 0.902; 95% confidence interval, 0.000-1.000; P = 0.030). Conclusions: Dynamic chest radiography is a minimally invasive tool for heart failure hemodynamic assessment.