Prevalence of coronary artery fistulae after cardiac surgery Comparison between coronary artery bypass grafting, valve surgery, and orthotopic heart transplantation

Coronary artery fistulae (CAF) are anomalous connections from a coronary artery to a recipient pulmonary vessel or cardiac chamber, and are reported in 0.2 % of the general population. The prevalence of CAF in the modern orthotopic heart transplant (OHT) population has been demonstrated to be significantly higher. The mechanism is unknown but one proposal is endothelial and vascular growth factor activation from injury. We hypothesize an incremental increase in CAF prevalence with the complexity of surgery, such that patients who have undergone OHT surgery would have an increased prevalence of CAF, as compared with patients who have undergone coronary artery bypass (CABG) surgery with valve surgery and as compared with patients who have undergone CABG surgery only. Consecutive angiograms of 481 patients after CABG surgery and 432 patients after OHT were reviewed. Patients who had previous valve surgery in addition to CABG were identified. Presence of CAF was determined. The chi-squared test was used for statistical analysis. In all, 436 patients had CABG only (group A), 45 patients had CABG with valve surgery (group B), and 432 patients had OHT (group C). The mean age of patients at the time of surgery for group A, B, and C was 59.0, 66.1, and 55.3 years, respectively. The percentage of male patients was 78.4, 77.8, and 77.1 %, respectively. We found 10 patients (2.3 %) with CAF in group A compared with 4 patients (8.9 %) in group B, and 88 patients (20.4 %) in group C, which was statistically significant (p < 0.001). All CAF were small, were not associated with hemodynamic compromise or significant adverse events, and were managed conservatively. There is an increased prevalence of CAF formation both after CABG and OHT compared with the general population. The higher prevalence of CAF in patients who additionally underwent valve surgery or who underwent OHT may be attributed to differences in surgical complexity. The increased prevalence of CAF formation after OHT compared with CABG should be further investigated.