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To the Editor,

We appreciate the authors’¹ interest in our article entitled “Congenital absence of the left circumflex artery in a patient presenting with acute inferior myocardial infarction.”² The authors claim that a small left circumflex artery (LCX) is present, originating from a proximal part of the left main coronary artery (LMCA), and the right coronary artery (RCA) seems to end after supplying the posterior wall of the left ventricle. When we checked coronary multislice computerized tomography images, the first branch of LMCA was the diagonal branch of the left anterior descending (Figure 1). The congenital absence of LCX is a very rare anomaly with an incidence of 0.0067%.³ A superdominant right coronary artery (RCA) and sometimes a large diagonal branch supply the inferior, lateral, and posterior walls of the left ventricle in the absence of LCX.⁴ A very large-sized and dominant RCA courses through the left atrioventricular groove and gives branches that supply the posterolateral site of the left ventricle in our case, in concordance with current literature, as shown in Figure 2. Similar cases were presented by Rawala et al⁵ (Figure 3) and Hong et al⁶ (Figures 4 and 5).

Additionally, the authors noted that the length of the LMCA in our case is abnormally long, and the circumflex artery is similar to that reported by Khurana et al⁷ In that case report, 19.2 mm of LMCA length was defined as unusually long. Also, in a study, the mean length of LMCA was reported to be 9.5 mm, and the maximum length was 32 mm.⁸ But in our case, the LMCA length was 36 mm, which is much longer than the maximum length reported in the previously mentioned case report and the study.

The absence of LCX is a challenging diagnosis; it may be misdiagnosed as a complete occlusion of LCX. The diagnosis should be strengthened with multimodality imaging such as conventional coronary angiography and coronary CT angiography.

Footnotes

Declaration of Interests: The authors have no conflicts of interest to declare.

References

1. Xu Z, Zhang Y. Reevaluating the Case of an Allegedly Absent circumflex artery: A Detailed Analysis of İnce et al.’s Report. Anatol J Cardiol. 2024;28(5):258-259.
2. Ince O, Gülşen K, Tuğrul S, Şahin İ, Okuyan E. Congenital absence of the left circumflex artery in a patient presenting with acute inferior myocardial infarction. Anatol J Cardiol. 2020;24(4):E11-E12. https://doi.org/10.14744/AnatolJCardiol.2020.62605
3. Fugar S, Issac L, Okoh AK, Chedrawy C, Hangouche NE, Yadav N. Congenital absence of left circumflex artery: A case report and review of the literature. Case Rep Cardiol. 2017;2017():6579847-. https://doi.org/10.1155/2017/6579847
4. Villa AD, Sammut E, Nair A, Rajani R, Bonamini R, Chiribiri A. Coronary artery anomalies overview: the normal and the abnormal. World J Radiol. 2016;8(6):537-555. https://doi.org/10.4329/wjr.v8.i6.537
5. Rawala MS, Ahmed AS, Iqbal MA, Iqbal A, Budde PK, Rizvi SB. Congenital anomaly of coronary artery: absence of left circumflex artery. J Community Hosp Intern Med Perspect. 2019;9(2):140-142. https://doi.org/10.1080/20009666.2019.1593784
6. Hong PS, Lee YS, Lee JB. Congenital absence of the left circumflex coronary artery in a patient with acute inferior myocardial infarction. Herz. 2014;39(8):957-959. https://doi.org/10.1007/s00059-013-3893-0
7. Khurana R, Pandey NN, Yadav S, Kumar S. Long main stem of left coronary artery with resultant meandering course of left circumflex artery. J Card Surg. 2022;37(7):2110-2111. https://doi.org/10.1111/jocs.16556
8. Fox C, Davies MJ, Webb-Peploe MM. Length of left main coronary artery. Br Heart J. 1973;35(8):796-798. https://doi.org/10.1136/hrt.35.8.796