Syphilitic Proximal Coronary Stenosis with Discordant Serology: Diagnostic Validation by Optical Coherence Tomography

Jingjie Xiong¹Ting Gan²Jing Hu³Wenhu Liu¹Xuehua Wang¹Han li¹Jiaxi Lv¹Ni Xiong¹Yanli Huang¹Qianyi Liu¹Huili Yin¹Yan Wang¹Ya Wang^1*Zhaohui Wang^1*

• ¹Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
• ²Beijing Anzhen Hospital Affiliated to Capital Medical University, Beijing, China
• ³Huazhong University of Science and Technology Tongji Medical College Union Hospital, Wuhan, China

Cardiovascular syphilis, a late manifestation of Treponema pallidum infection, remains a diagnostic challenge, particularly when serological tests are discordant. We report a case of a 70-year-old male with recurrent chest tightness and discordant syphilis serology (non-reactive RPR, reactive TPPA). Coronary angiography revealed a critical stenosis at the distal left main coronary artery, specifically involving the ostio-proximal segment of the left anterior descending (LAD) artery.. Critically, the absence of systemic atherosclerosis was evidenced by a coronary artery calcium score of zero and normal carotid intima-media thickness. Optical coherence tomography (OCT) provided definitive diagnostic clarity by revealing microstructural features pathognomonic for syphilitic vasculitis: vasa vasorum obliteration, elastic lamina fragmentation, and adventitial fibrosis with microcalcifications. These findings were distinct from atherosclerotic plaque. The patient successfully underwent OCT-guided percutaneous coronary intervention followed by targeted antibiotic therapy. This case highlights the indispensable role of OCT in establishing the etiology of non-atherosclerotic proximal coronary stenosis, underscoring that cardiovascular syphilis must be considered even with non-reactive non-treponemal tests in late-stage disease.