Commissural Malalignment as a predictor of coronary artery abnormalities in patients with transposition of great arteries

Abstract

Background

In patients with transposition of the great arteries (TGA), commissural malalignment (CM) between semilunar valves may be associated with abnormal coronary (CA) pattern. We intend to assess the degree of CM with incidence of unusual CA anatomy.

Methods

We proposed a ratio to measure the distance of both ends of the anterior facing sinuses of the pulmonary valve from the facing commissure of the aortic valve. We labeled it as D1 and D2 distance. A ratio (C ratio) of the smaller distance (either D1 or D2 whichever is shorter) over the sum of both D1 and D2 was taken (D1 or D2 whichever is shorter / D1 + D2). We related this ratio with the incidence of the unusual CA anatomy in D-TGA patients.

Results

We had a total of 158 patients. We defined the point beyond which the C-Ratio becomes significantly associated with abnormal coronary artery pattern, this represents the median effective level (EL50). The EL50 of the C-Ratio was found to be equal to 31% (0.31). The prediction revealed that the CA pattern would most probably be usual when there is a minor commissural malalignment (C-Ratio less than the EL50) and most probably be unusual when there is a major malalignment (C-Ratio is greater than the EL50). The sensitivity was 71% and the specificity 88% (p-value < 0.0001).

Conclusions

The C-Ratio helps to categorize the degree of CM as minor (less than 0.31) or major (more than 0.31). A higher C-Ratio predicts a higher incidence of unusual CA pattern.