Long-term outcome of conservatively treated patients with borderline coronary lesions--role of the fractional flow reserve measurement.

BACKGROUND: Coronary fractional flow reserve (FFR) has been recommended as one of the functional methods which can be used to establish indications for revascularisation in patients with borderline coronary lesions. AIM: To assess long-term outcome of patients with borderline coronary lesions in whom the decision to implement conservative treatment was based on the results of FFR. METHODS: The study group consisted of 41 patients (13 females, mean age 61+/-9 years) who had CCS class II angina, an isolated borderline (40-70%) coronary lesion and FFR >0.75. All patients received 40 mg of simvastatin, angiotensin converting enzyme inhibitor and aspirin. The follow-up duration ranged from 7 to 32 months (mean 15.2+/-7.1, median 14.5 months). The analysed end-points included cardiac death, myocardial infarction (MI) (with or without ST segment elevation) and revascularisation of the target coronary artery. RESULTS: The mean FFR value in the whole study group was 0.91+/-0.05. Three (7%) patients had complications during follow-up: one patient developed MI, and two had coronary artery stenosis progression, requiring angioplasty. These patients had similar clinical and angiographic characteristics as well as FFR values as patients without complications. Among patients with uneventful outcome, in 33 (87%) anginal symptoms improved whereas in the remaining 5 (13%) patients CCS class did not change. Patients with angina alleviation were older and had higher FFR values than patients without improvement (63+/-8 vs 48+/-6 years, p=0.0005; and 0.92+/-0.05 vs 0.86+/-0.08, p=0.04, respectively). CONCLUSIONS: In patients with borderline coronary lesions and stable angina, angioplasty can be delayed on the basis of the FFR results. This approach is safe and is associated with an asymptomatic long-term follow-up in more than 90% of patients.