CT-fractional flow reserve analysis shows significant blockage in patient with chest pain, but conventional tests show no indications of decreased blood flow to the heart.
In July 2022, a 45-year-old male with a six-year history of chest pain went to the emergency room complaining of chest discomfort and shortness of breath over the previous two weeks. He was evaluated by Jacqueline Gray, APRN, and no markers of heart attack were found.
Previously, nuclear stress single-photon emission computerized tomography (SPECT) scan did not indicate any decrease in blood flow to the heart. In 2020, a nuclear stress positron emission tomography/CT (PET/CT) scan did not demonstrate any ischemia or lack of blood supply to the heart. But calcium was noted in the heart arteries on the CT portion. The patient had several risk factors for coronary artery disease.
Nuclear stress tests for ischemia in 2016 and 2020 did not demonstrate lack of blood supply to the heart, but the patient continued to have recurrent chest pain and shortness of breath. Normally, an invasive test may be necessary to identify any significant obstructions and their locations, which would inform treatment that could include additional invasive measures.
The provider team
Jacqueline conferred with Dr. Raible. They decided to proceed with a coronary CT angiogram (CCTA), a possible CT-fractional flow reserve (CT-FFR) analysis and an echocardiogram.
CCTA demonstrated some atherosclerotic plaque in all of the major coronary arteries, with the left anterior descending artery having the most obstruction at greater than 70%. There were plaques in the other arteries, with plaque present in the intermediate 30% to 70% range of narrowing, that required further analysis as to whether blood flow was being restricted.
If significant obstruction were present only in the left anterior descending artery, a coronary stent could be placed in the catheterization lab. If several arteries had significantly obstructed flow, then coronary artery bypass surgery likely would be needed. The CCTA images were submitted for the CT-FFR analysis using HeartFlow.
The CT-FFR HeartFlow analysis showed levels of obstruction and their location.
CT-FFR analysis values are considered abnormal if less than or equal to 0.80. The patient’s left anterior descending artery and diagonal vessels had CT-FFR values of 0.67 and 0.80, the left circumflex and marginal vessels had values of 0.74 and 0.59, and the right coronary artery CT-FFR was 0.80. With multiple vessels involved, the patient likely would require coronary bypass surgery.
Cardiac catheterization with invasive diagnostic coronary angiography confirmed significant obstructive disease. The patient was referred for coronary artery bypass graft surgery with four grafts performed.
The CCTA identified multivessel coronary artery disease. The additional CT-FFR analysis from the baseline coronary CTA data provided the physiologic assessment that determined obstructive disease in all major coronary vessels was restricting blood flow to the heart. As a result, anatomic and functional assessments were determined just from the coronary CT angiogram data at rest without the administration of pharmacologic stress agents or a second scan.
After cardiac bypass surgery, the patient had steady improvement in recovery. He returned to work without recurrence of his previous cardiac symptoms.
Treatment and results may not be representative of all similar cases.