Coronary-to-pulmonary artery fistula in adults: Evaluation with thallium-201 myocardial perfusion SPECT.

Objectives: With the increasing use of multi-detector CT, the number of detected cases with coronary-to-pulmonary artery fistula (CPAF) has increased. Several previous studies reported severe cases of angina, but no appropriate tests to evaluate myocardial perfusion for patients with CPAF have been established. We evaluated the hemodynamic characteristics of CPAF using thallium-201 (Tl-201) single photon emission computed tomography (SPECT).
Materials and Methods: Tl-201 SPECT was performed in 17 patients with CPAF, but without evidence of coronary artery disease on coronary computed tomography angiography (CCTA) (age, 58.5±13.3 years; 8 men). Quantitative analysis of scintigraphic data was performed. Additionally, perfusion abnormalities were compared with CCTA findings. Medical records were obtained to define clinical data, diagnostic findings, symptoms, management, follow-up data, and major adverse cardiac events (MACE).
Results: Six patients (35.2%) showed perfusion abnormalities on SPECT studies and could be classified as follows: 3 patients, no reversible ischemia (3/17, 17.6%); 1 patient, mild ischemia (1/17, 5.8%); and 2 patients, moderate ischemia (2/17, 11.7%). During the follow-up, ten patients (58.8%) improved under medical management and 5 patients (29.4%) underwent surgical ligation for CPAF with symptomatic improvement in 4 patients. Seven patients performed follow-up myocardial perfusion SPECT, and symptomatic improvement correlated well with scintigraphic perfusion improvement in 6 patients No MACE was observed.
Clinical Significance: Tl-201 myocardial perfusion SPECT might be useful for determining the hemodynamic status and for risk stratification in patients with CPAF.