Does fractional flow reserve overestimate severity of LAD lesions?

BACKGROUND: Fractional Flow Reserve (FFR) is increasingly used to estimate the severity of coronary stenoses, prior to coronary revascularization. However, it has been suggested that FFR overestimates the severity of Left Anterior Descending (LAD) lesions. Our aim was to verify whether in patients without ischemia on Myocardial Perfusion Imaging, FFR of the LAD is more often abnormal in comparison to FFR of other coronary arteries. METHODS: Prospective cohort study of consecutive patients who underwent FFR measurement because of persistent or worsening of angina complaints, within 6 months after normal Myocardial Perfusion Imaging. FFR measurements of a graft or diagonal branch were excluded. A FFR ≤ 0.80 denoted a functionally relevant stenosis. RESULTS: In 133 patients, 167 FFR measurements were performed, of which 85 in the LAD. Mean age of the patients was 64.8 ± 10.5 years, 40% were women. There were no differences in baseline characteristics between patients undergoing LAD and non-LAD measurements. An abnormal FFR was observed in 35.3% of the LAD measurements, compared to 9.8% in the non-LAD measurements (P = 0.001). Also after adjusting for age and gender, the FFR remained more frequently abnormal in the LAD with OR 5.2 (95% CI 2.2 to 12.3). Of the abnormal FFR LAD measurements, 70% were visually considered non-obstructive on invasive angiography. CONCLUSIONS: In selected patients without ischemia on MPI, FFR measurement of the LAD is significantly more often abnormal. The majority of these patients has no obstructive lesions on invasive angiography. Possibly, FFR overestimates severity of LAD lesions, with risk of unnecessary revascularization.

Influence of coronary calcification on hyperemic response during fractional flow reserve measurements.

AIM: During invasive fractional flow reserve (FFR) adenosine and nitrates are used to obtain maximal hyperemia. Severe coronary artery calcification (CAC) is associated with impaired vasodilation. We investigated the hyperemic response during FFR in vessels with severe versus mild CAC. METHODS AND RESULTS: We retrospectively selected 236 patients who underwent both CAC scoring and invasive FFR. FFR was performed in 304 vessels with intermediate stenoses. Delta (Δ) FFR, the pressure gradient before the administration of adenosine minus FFR after the administration of adenosine, was used to investigate the hyperemic response. Mean age of the total population was 65 ±â€¯10 years, 65% was male. Median CAC score was 510 (range 0 to 6141). Mean pressure gradient before the administration of adenosine was comparable in vessels with severe versus mild CAC. FFR was more often ≤0.80 in vessels with severe CAC (p = 0.045). Patients with a large Δ FFR were younger (p = 0.05). There was no association between Δ FFR and severity of calcifications. Regression analysis did not demonstrate an association between CAC score and the hyperemic response (p = 0.49). CONCLUSION: We did not find an association between the severity of CAC and the hyperemic response during invasive FFR.

Coronary artery stenoses more often overestimated in older patients: Angiographic stenosis overestimation in elderly.

BACKGROUND: Angiographic overestimation of coronary artery stenosis severity may result in unnecessary revascularization and is possibly more prevalent with increasing age. AIM: To identify whether age is an independent clinical predictor for angiographic overestimation of a coronary artery stenosis. METHODS: Fractional flow reserve (FFR) of 335 coronary lesions was performed in 260 consecutive patients with stable coronary artery disease (CAD). Overestimation was defined as an angiographically significant stenosis, with normal FFR (>0.80). Age was analysed as both continuous variable and quartiles. The highest age quartile was compared to the remaining quartiles. Multivariable analyses were performed to adjust for differences in baseline variables. RESULTS: Mean age of the total population was 65±10years, overestimation was observed in 11%. Mean age of patients with overestimation was 69±11years, compared to 65±10years in those without overestimation (p=0.01). Overestimation was observed significantly more often in the highest age quartile (22%) in comparison with the younger patients (8.0%) (p<0.001). The adjusted odds ratio for overestimation in the highest quartile group was 3.15 (95% confidence interval: 1.48-6.69). CONCLUSION: Increasing age is a strong and independent predictor for angiographic overestimation of the severity of a coronary stenosis. Functional measurement of coronary artery stenoses should be considered more often, particularly in elderly to avoid unnecessary revascularization.

Angiographic underestimation of disease severity in the left anterior descending artery: a fractional flow reserve analysis.

OBJECTIVES: This study compared the prevalence of angiographic underestimation of left anterior descending artery (LAD) lesions with non-LAD lesions. BACKGROUND: Coronary angiography cannot assess the functional severity of a coronary stenosis. Previous studies suggested that lesions of the LAD are more often angiographically underestimated, but evidence is limited. MATERIALS AND METHODS: Fractional flow reserve (FFR) was performed in 335 coronary lesions (187 LAD lesions and 148 non-LAD lesions). A visually estimated diameter stenosis of at least 70% was considered functionally significant. An FFR value of up to 0.80 was considered significant. Multivariable analyses were carried out. RESULTS: Angiographically, LAD lesions as well as non-LAD lesions were considered functionally significant in 29% (P=0.94). FFR showed significant stenosis of the LAD in 52% compared with 24% in non-LAD lesions (P<0.001). Underestimation was observed in 30% of LAD lesions compared with 11% in non-LAD lesions (P<0.001). The adjusted odds ratio for underestimation in LAD lesions in comparison with non-LAD lesions was 3.48 (95% confidence interval 1.89-6.41; P<0.001). CONCLUSION: Underestimation of the functional severity of a coronary stenosis is more common in LAD lesions. FFR should be performed more often for intermediate stenosis of the LAD.