Borderline coronary lesions may lead to serious coronary events--long-term outcome in 65 conservatively treated patients.

BACKGROUND: The choice of optimal therapy in a patient with borderline coronary lesion is difficult. The long-term outcome of conservatively treated patients has not yet been well defined. AIM: To analyse long-term outcome in patients with a borderline lesion in a single coronary artery who were selected for conservative treatment. METHODS: The study group consisted of 65 patients (mean age 59.4+/-7.4 years, 48 males) with (1) stable angina (CCS class I/II), (2) isolated single borderline coronary lesion (40-70% stenosis demonstrated by quantitative coronary angiography) and (3) no demonstrable ischaemia during non-invasive tests. Patients with heart failure, left ventricular ejection fraction <50% or acute coronary syndrome within 6 months preceding the study were not included. All patients were prescribed statins, angiotensin converting enzyme inhibitors and aspirin. Follow-up end-points included cardiac death, new myocardial infarction (MI) with or without ST segment elevation and revascularisation of the target coronary artery. RESULTS: The follow-up duration was 18.4+/-8.5 months (range 12-33, median 18 months). Forty nine (75%) patients remained free from angina during daily activity. Coronary events occurred in 16 (25%) patients, including three (5%) serious complications -- sudden death, new MI with ST elevation and new MI without ST elevation. The remaining 13 (20%) patients underwent percutaneous revascularisation of the target coronary artery. Coronary angiography was repeated in 16 (25%) patients. When the patients were divided into two groups according to the follow-up results (with or without coronary event), no differences in the clinical characteristics, lesion localisation and length or degree of stenosis were noted. CONCLUSIONS: (1) Conservatively treated patients with stable angina and borderline coronary stenosis have a high rate of coronary events, especially revascularisation, during a long-term follow-up. (2) Clinical parameters and quantitative coronary angiography do not identify those patients with borderline coronary lesions who are at increased risk of future coronary events.

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.

Measurement of fractional flow reserve in patients with multi-vessel coronary artery disease and borderline lesions prevents unnecessary revascularisation procedures.

BACKGROUND: Patients with multi-vessel coronary artery disease (CAD) are selected for percutaneous coronary interventions (PCI) or surgical revascularisation. The appropriateness of "ad hoc" PCI of borderline lesions (<70% of lumen diameter) in patients with a multi-vessel CAD has not been proven. However, delayed PCI of another lesion and gaining additional information from non-invasive tests is not a widely accepted strategy. When left anterior descending (LAD) coronary artery is one of the affected vessels, selection for surgical revascularisation is most likely. AIM: To assess long-term outcome in patients with multi-vessel CAD and borderline lesions, including LAD, in whom fractional flow reserve (FFR) in all affected vessels was measured and used for selection for PCI or conservative treatment. METHODS: The study group consisted of 16 patients with stable angina (11 males, mean age 60+/-9 years) with 34 lesions localised in the main epicardial coronary arteries [LAD / left main (LM) / right coronary artery (RCA) / intermediate branch (IB) / circumflex artery (Cx) - 15/1/5/5/8] of which at least two were borderline stenoses. Each lesion underwent FFR measurement. "Ad hoc" PCI was performed when FFR was <0.75, and conservative therapy was instituted when FFR was >0.75. RESULTS: Of 34 lesions, in 8 (23%) the FFR value was <0.75 and these lesions were treated with PCI (LAD/IB/Cx - 3/2/3). In the remaining 26 (77%) lesions, FFR was >0.75 and conservative therapy was instituted. During the mean follow-up of 15+/-6 months (range 6-28 months, median 15 months) in 8 of 9 conservatively treated patients no aggravation of anginal symptoms nor other coronary events were observed. One patient developed acute myocardial infarction due to thrombus occluding a borderline LAD lesion. Of 8 lesions treated with PCI (baseline FFR = 0.63+/-0.10 vs post-PCI FFR = 0.92+/-0.08, p=0.0002), in one case an in-stent restenosis in LAD occurred 9 months after PCI. Of a total of 26 lesions which were conservatively treated (mean FFR 0.91+/-0.05), in 2 (7.7%) the progression of CAD was noted. CONCLUSIONS: In patients with multi-vessel CAD and borderline lesions, FFR measurement identifies those, who can be treated conservatively with a good long-term outcome, and prevents unnecessary PCI.

Measurement of coronary fractional flow reserve. Standard doses of intracoronary adenosine are insufficient to induce maximal hyperaemia.

BACKGROUND: Induction of maximal hyperaemia is a prerequisite for a reliable estimation of fractional flow reserve (FFR) in a moderate coronary artery stenosis. Intracoronary adenosine is the most frequently used agent to achieve maximal hyperaemia. However, an insufficient dose of adenosine may induce only partial hyperaemia, thus artificially increasing the FFR values. AIM: To assess the tolerability and effects on FFR value of increased doses of adenosine. METHODS: FFR was measured in 36 patients with 53 moderate coronary lesions. In order to induce maximal hyperaemia and assess FFR in the targeted coronary artery, intracoronary adenosine in a dose of 30 micro g was administered twice (FFR30). Next, 60 micro g of adenosine was tested twice (FFR60). In addition, in some patients with left coronary artery stenosis, 90 micro g of adenosine was also injected (FFR90). RESULTS: No significant side effects were noted except a transient, self-terminating episode of a second degree atrio-ventricular block in one patient. The mean value of FFR30 was significantly higher than FFR60 (0.854+/-0.152 vs 0.836+/-0.162, p<0.001), and the mean difference between these two measurements was 0.018+/-0.036. In 29 (54.7%) evaluated lesions, FFR30 values were higher than FFR60; in 12 (22.6%) measurements the difference exceeded 0.02, and in 8 (15%) cases - 0.05. The use of 90 micro g of adenosine did not further decrease FFR in any of the cases. CONCLUSIONS: An increase of the adenosine dose from 30 micro g to 60 micro g was well tolerated and caused further decrease in the FFR values which may be of clinical importance in some patients. The use of 90 micro g of adenosine did not further decrease FFR.