Internal mammary artery atherosclerosis in segments removed during coronary artery bypass grafting surgery and C.pneumoniae infection.

Objective: Recent studies suggest the association of atherosclerotic cardiovascular disease with Chlamydia pneumoniae infection. We investigated C. pneumoniae DNA in internal mammarian artery (IMA) (used as a coronary bypass conduit) and its relationship with atherosclerosis.

Methods: Sixty-six consecutive patients who underwent coronary artery bypass grafting (CABG) during an eight-month period were included in this study. From all patients, we attempted to obtain surplus segments of harvested IMA grafts. The vessels were examined histopathologically, and presence of C. pneumoniae DNA in IMA grafts was assessed by polymerase chain reaction (PCR).

Results: C. pneumoniae DNA was found in 7 (10.6%) of 66 IMA specimens. The light microscopic examinations of IMA segments from the C. pneumonia positive group showed atherosclerotic intimal changes in four of the seven patients. These atherosclerotic changes were type II in three patients and type III in one patient according to the AHA classification. The rest of the IMA segments from 62 patients did not show any discernible atherosclerotic lesion.

Conclusion: The IMA graft examination by PCR and histopathology may be helpful in the determination of future graft patency for IMA bypass surgery.