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

Abstract

Background: 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.

Aims: to perform a correlation and concordance study between quantitative coronary angiography (QCA) and intravascular ultrasound measurements for intermediate and ambiguous lesions.

Methods: 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.

Results: 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 &Altaman diagrams showed however wide limits of agreement, reflecting possibility of large measurements error and confirming the absence of concordance between the two techniques.

Conclusion: 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.