[Limits of quantitative coronary angiography [QCA] in intermediate stenosis measuring: a correlation and concordance study with intravascular ultrasound [IVUS]]

ABSTRACT

Although coronarography is still the gold standard to evaluate coronary lesions, it remains a bidimensional representation of a tridimensional complex structure, which can represent a source of error in measurements. To perform a correlation and concordance study between quantitative coronary angiography [QCA] and intravascular ultrasound measurements for intermediate and ambiguous lesions. We analysed 40 patients' coronary arteries from March 2009 to November 2011 by both QCA and intravascular ultrasound to perform then a correlation and concordance study. The correlation study confirmed the limits of the angiogram in providing accurate measurements. The correlation coefficient was yet high in reference diameters [r=0,78, p<0,001] and minimal lumen diameters [r=0,58, p<0,001], but was middling for stenosis percentages [r=0,23, p=0,03]. This coefficient was also high for lesions lengths [r=0,51, p=0,01]. Bland and Altaman diagrams showed however wide limits of agreement, reflecting possibility of large measurements error and confirming the absence of concordance between the two techniques. Coronarography though being the most widespread mean of evaluating coronary lesions lacks to provide accurate measurements, which can influence patient's management, especially in case of intermediate lesions