Role of On-site CT-derived FFR in the Management of Suspect CAD Patients

Based on the clinical fact that less stress myocardial perfusion scan are performed rather than stress exercise electrocardiogram (ECG) in China, more patients undergo coronary computed tomographic angiography (CTA) for determining whether they should be sent to catheter lab. However, nearly 30% of patients sent to catheter lab were found without obstructive coronary artery disease (CAD) and this invasive procedure was unnecessary and overused partly. Fortunately, fractional flow reserve (FFR) based non-invasive CT algorithm technology (CT-FFR) showed a great potential in detecting functional myocardial ischemia related to coronary specific lesion (Discovery-Flow, DEFACTO and NXT trial)[1-3]. Moreover, clinical care guided by CT-FFR could provide benefits with equivalent clinical outcomes and lower expenditure, compared with routine clinical care over 1-year follow-up (Platform trial). On the other aspect, ADVANCE trial revealed that CT-FFR modified treatment recommendation was associated with less negative invasive coronary angiography (ICA), predicted revascularization and identified subjects at low risk of adverse events through 90 days in real-world. However, these studies was not randomized designed and selection bias still existed. So our trial aims to evaluate whether CTA/CT-FFR outperforms the regular diagnostic care in ruling out patients without significantly obstructive CAD before catheter lab and improving clinical prognosis during follow-up in a randomized design.

Inclusion criteria

• New-onset chest pain suspicious for CAD
• Coronary CTA result showed that the diameter stenosis is between 30 and 90% in at least one major coronary artery (coronary artery diameter ≥ 2.5 mm)
• Intermediate-to-high pretest probability of CAD based on CAD Consortium Score
• No prior evaluation for this episode of symptoms
• Agree to participate in this clinical study and sign written informed consent

Exclusion criteria

• Diagnosed or suspected acute coronary syndrome requiring hospitalization or emergent testing
• Hemodynamically or clinically unstable condition systolic blood pressure < 90 mmHg or serious atrial or ventricular arrhythmias
• Known CAD with prior myocardial infarction, percutaneous coronary intervention (PCI), coronary artery bypass graft (CABG), or any angiographic evidence of ≥ 50% stenosis in any major coronary artery
• Patients with left main branch stenosis ≥ 50% or major coronary artery stenosis > 90%
• Known severe congenital, valvular (moderate and above), or cardiomyopathy process (hypertrophic cardiomyopathy or reduced systolic left ventricular function ≤ 40%) which could explain cardiac symptoms
• Unable to provide written informed consent or participate in long-term follow-up.