Validation of videodensitometric myocardial perfusion assessment

Introduction Invasive methods for assessment of coronary microcirculatory function are time- and instrumentation-consuming tools. Recently, novel computer-assisted videodensitometric methods have been demonstrated to provide quantitative information on myocardial (re)perfusion. The aim of the present prospective study was to evaluate the accuracy of videodensitometry-derived perfusion parameters in patients with stable angina undergoing elective coronary angiography. Methods The study comprised 13 patients with borderline epicardial coronary artery stenosis (40–70%). Coronary flow reserve and index of microcirculatory resistance were measured by using an intracoronary pressure and temperature sensor-tipped guidewire. A videodensitometric quantitative parameter of myocardial perfusion was calculated by the ratio of maximal density (G max ) and the time to reach maximum density (T max ) of the time-density curves in regions of interest on conventional coronary angiograms. Myocardium perfusion reserve was calculated as a ratio of hyperemic and baseline G max /T max . Results At hyperemia a significant increase in G max /T max could be observed (p <0.0001). Significant correlations were found between myocardium perfusion reserve and coronary flow reserve (r =0.82, p =0.0008) and between hyperemic G max /T max and hyperemic index of microcirculatory resistance (r =−0.72, p =0.0058). Conclusions Videodensitometric Gmax/Tmax assessment seems to be a promising method to assess the myocardial microcirculatory state.