From the Guidelines
HeartFlow study is primarily indicated for patients with stable chest pain who have intermediate risk of coronary artery disease (CAD) and require further evaluation after an initial coronary CT angiogram. This is based on the most recent and highest quality evidence available, which prioritizes the reduction of morbidity, mortality, and improvement of quality of life as outcomes. The indications for HeartFlow study can be broken down into several key points:
- Patients with intermediate risk of coronary artery disease (CAD) who require further evaluation after an initial coronary CT angiogram 1
- Coronary lesions of uncertain significance (typically 30-70% stenosis) detected on CT angiography 1
- Patients who have contraindications to stress testing, inconclusive stress test results, or when there's a discrepancy between clinical symptoms and other test results
- The study helps cardiologists make more informed decisions about which patients truly need invasive coronary angiography and potential revascularization versus those who can be managed with medical therapy alone 1 Some key considerations for the use of HeartFlow study include:
- The need for a good quality coronary CT scan with minimal motion artifacts
- The study is not appropriate for patients with acute coronary syndromes, previous coronary stents or bypass grafts, or significant arrhythmias that would compromise image quality
- The presence of diabetes mellitus or other clinical atherosclerotic disease may also be a consideration in the decision to use HeartFlow study 1
From the Research
Indications for Heart Flow Study
The indications for a heart flow study, also known as fractional flow reserve computed tomography (FFRct), include:
- Diagnosing myocardial ischemia in patients with suspected stable coronary artery disease (CAD) 2
- Identifying hemodynamically significant CAD 2
- Guiding diagnostic strategies and treatment decisions in patients with suspected CAD 3
- Evaluating coronary artery stenosis and planning potential interventional or surgical therapy 4
- Assessing patients with chest pain and suspected CAD, particularly when anatomy of the heart and thoracic vessels/structures is mandatory 4
Patient Selection
Heart flow study is particularly useful in patients with:
- Intermediate stenosis (30-70% diameter stenosis) 2
- Suspected CAD and new onset chest pain 3
- Normal electrocardiogram and suspected CAD 5
- Known or suspected coronary artery disease undergoing coronary angiography (CAG) 6
Diagnostic Accuracy
The diagnostic accuracy of heart flow study is high, with:
- Area under the receiver-operating characteristic curve of 0.90 for FFRct 2
- Sensitivity and specificity of 86% and 79% for FFRct, respectively 2
- Higher diagnostic accuracy and discrimination compared to coronary CTA alone 2, 3
- Improved diagnostic specificity and accuracy compared to traditional semi-quantitative gated MPI 6