Artery Stenosis Of Intermediate Severity Research Articles

350 - Comparison of the instantaneous wave-free ratio and resting Pd/Pa with fractional flow reserve to assess coronary artery stenosis of intermediate severity

350 - Comparison of the instantaneous wave-free ratio and resting Pd/Pa with fractional flow reserve to assess coronary artery stenosis of intermediate severity

Assessment of left anterior descending artery stenosis of intermediate severity by fractional flow reserve, instantaneous wave-free ratio and non-invasive coronary flow reserve

Ninety-four stable consecutive patients (mean age, 68±10years; 19 women) with angiographic proximal or mid LAD stenosis of intermediate severity (40-70% diameter stenosis on quantitative coronary angiography), were prospectively studied. They underwent IFR that was calculated as a trans-lesion pressure ratio during a specific period of baseline diastole, FFR with intracoronary bolus adenosine (180μg), and CFR using intravenous adenosine (140μg/kg/min over 2min) in the distal part of the LAD, the same day. CFR was defined as hyperemic peak diastolic LAD flow velocity divided by baseline flow velocity and FFR as distal pressure divided by mean aortic pressure during maximal hyperemia. The mean values of IFR, FFR, and CFR were 0.88±0.07, 0.81±0.09, and 2.4±0.6 respectively. A significant correlation was found between CFR and FFR (R=0.63, curvilinear relationship), FFR and IFR (R=0.6, linear relationship), and between CFR and IFR (R=0.5) (all, P<0.01). Using a ROC curve analysis, the best cut-off to detect a significant lesion based on FFR assessment (FFR≤0.8, N=31) was IFR≤0.88 with a sensitivity (Se) of 74%, specificity (Sp) of 73%, AUC 0.81±0.04; and CFR≤2 with a Se=77%, Sp=89%, AUC 0.88±0.04, (all, P<0.001). Based on these cut-offs, discordant results between CFR and FFR were observed in 14 cases (agreement 85%), between CFR and IFR in 26 cases (agreement 72%), and between IFR and FFR in 26 cases (agreement 72%). In stable patients with LAD stenosis of intermediate severity, non-invasive CFR is a useful tool to detect a significant lesion based on FFR. Furthermore, there was a better correlation and agreement between CFR and FFR than with IFR.

Fractional flow reserve and intravascular ultrasound in the assessment of moderate coronary lesions: a comparative study

Objective The aim of this study was to assess intermediate coronary lesions as detected by visual estimation in coronary angiography using two invasive modalities: fractional flow reserve (FFR) and intravascular ultrasound. Background The significance of coronary artery stenosis of intermediate severity can be difficult to determine. The management of intermediate coronary lesions, defined by a diameter stenosis of more than 40% to less than 70%, continues to be a therapeutic dilemma for cardiologists. The two-dimensional representation of the arterial lesion provided by angiography is limited in distinguishing intermediate lesions that require stenting from those that simply need appropriate medical therapy. Patients and methods Thirty patients with intermediate coronary stenosis on coronary angiography were subjected to a noninvasive stress test, either exercise myocardial perfusion imaging or stress echocardiography, and the results were compared with those of intravascular ultrasound and FFR. Results In this study, 30 patients were subjected to FFR measurement. Twelve of 14 patients had an FFR of less than 0.80; reversible ischemia was detected on the stress test. In contrast, only two of 16 patients with an FFR of more than 0.80 had a negative stress test for reversible myocardial ischemia. FFR value has a sensitivity and a specificity of 85.7 and 87.5%, respectively, in predicting the results of a noninvasive stress test, with a positive predictive value and negative predictive value of 85.7 and 87.5%, respectively, with an accuracy of 86.7%. It is also showed that the best cutoff value for the minimal luminal area that is concordant with FFR values is less than 4.5 mm 2 , which has a sensitivity and a specificity of 57.1 and 56.3%, respectively, and positive predictive value of 53.3% and negative predictive value of 60%. Conclusion In patients with coronary stenosis of intermediate severity, FFR appears to be a useful index for assessment of the functional severity of coronary artery stenosis in comparison with a noninvasive stress test and can be used as a guide before coronary revascularization.

Comparison between non-invasive coronary flow reserve and fractional flow reserve to assess the functional significance of left anterior descending artery stenosis of intermediate severity

Comparison between non-invasive coronary flow reserve and fractional flow reserve to assess the functional significance of left anterior descending artery stenosis of intermediate severity

Comparison Between Non-Invasive Coronary Flow Reserve and Fractional Flow Reserve to Assess the Functional Significance of Left Anterior Descending Artery Stenosis of Intermediate Severity

Assessment of the functional significance of left anterior descending coronary artery (LAD) stenosis of intermediate severity (50%-70% diameter stenosis) is challenging. The aim of this study was to compare the value of noninvasive coronary flow reserve (CFR) with that of invasive fractional flow reserve (FFR) in the setting of LAD stenosis of angiographic intermediate severity. Fifty stable consecutive patients (mean age, 63 ± 13 years; 11 women; mean left ventricular ejection fraction, 61 ± 10%) with angiographic proximal LAD stenoses of intermediate severity (55.5 ± 5% diameter stenosis on quantitative coronary angiography), no previous anterior myocardial infarction, and various vascular risk factors were prospectively studied. They underwent FFR assessment with intracoronary bolus adenosine (150 μg), and CFR assessment using intravenous adenosine (140 μg/kg/min over 2 min) in the distal part of the LAD on the same day in nearly all patients. CFR was defined as hyperemic peak diastolic LAD flow velocity divided by baseline flow velocity (normal value >2), and FFR was defined as distal pressure divided by mean aortic pressure during maximal hyperemia (normal value >0.8). The mean FFR and CFR were 0.84 ± 0.07 and 2.7 ± 0.75, respectively, in the whole population. Concordant results between FFR and CFR were seen in 44 patients (88%) and discordant results in six patients (12%). There was a significant correlation between CFR and FFR (r= 0.59, P < .01). A better correlation was found between FFR and percentage LAD diameter stenosis, and lesion length (all P values < .05), than between CFR and the same anatomic markers of stenosis severity (all P values= NS). The sensitivity, specificity, and positive and negative predictive values of CFR >2 to detect a nonsignificant lesion defined by normal FFR were 95%, 69%, 90%, and 82%, respectively. In patients with LAD stenosis of intermediate severity, discordant results between noninvasive CFR and FFR were not unusual, and the anatomic determinants of the stenosis were better correlated to FFR than to CFR. However, CFR, which is a global evaluation of the coronary tree, has very high sensitivity to detect a nonsignificant lesion, despite the high prevalence of vascular risk factors.

128 Comparison between non invasive coronary flow reserve and fractional flow reserve in the setting of left anterior descending artery stenosis of intermediate severity

The functional significance of left anterior descending artery (LAD) stenosis of angiographic intermediate severity (IS) (50–70% diameter stenosis) is challenging. to compare the value of non-invasive coronary flow reserve (CFR) to the invasive fractional flow reserve (FFR) in patients (pts) with LAD stenosis of IS. 46 consecutive pts (mean age 63 ± 13 years, 11 females, mean LVEF 63 ± 8%) with various risk factors (diabetes 17%, hypertension 52%, smoking 28%, dyslipidemia 74%), no previous anterior myocardial infarction, and with an LAD stenosis of IS (55 ± 5% diameter stenosis, QCA) were prospectively studied. They underwent FFR with intracoronary bolus adenosine (150 μg), 3 cms distal to the stenosis, and CFR using intravenous adenosine (140 μg/kg/min over 2 min), in the distal part of the LAD, the same day in nearly all cases. CFR was defined as hyperemic peak diastolic LAD flow velocity divided by baseline flow velocity (normal value ≥ 2) and FFR was defined as distal pressure divided by mean aortic pressure during maximal hyperemia (normal value ≥ 0.8). The mean FFR and CFR were 0.84 ± 0.07 and 2.8 ± 0.7 respectively. Concordant results between FFR and CFR were seen in 39 cases (85%) and discordant results in 7 cases (15%). There was a weak correlation between CFR and FFR (r = 0.43, p < 0.01). A better correlation was found between FFR and LAD diameter stenosis (r = −0.42, p < 0.01) than between CFR and LAD diameter stenosis (r = −0.23, p = 0.1), and between FFR and lesion length (r = −0.39, p < 0.05) than between CFR and lesion length (r = −0.27, p = 0.1). However, the sensitivity and the positive predictive value of CFR ≥2 to detect a non significant lesion defined by a normal FFR were high (94.5% and 87.5% respectively) in this setting. In pts with LAD stenosis of IS, discordant results between CFR and FFR were not unusual, and the anatomic determinants of the stenosis are better correlated to FFR than to CFR. However, CFR which is a global evaluation of the coronary tree has a very high sensitivity to detect a non significant lesion, despite the high prevalence of vascular risk factors.

Correlation between coronary computed tomographic angiography and fractional flow reserve

Coronary CT angiography (CCTA) has become an important modality to evaluate the presence of coronary artery disease. Coronary artery stenosis of intermediate severity remains a therapeutic dilemma. Measurement of fractional flow reserve (FFR) during coronary angiography is the most established technique to determine the hemodynamic severity of a coronary artery lesion. The aim of this study was to compare CCTA with FFR. In 56 coronary artery stenoses (42 patients) we performed CCTA, quantitative coronary angiography and FFR. CCTA measurements included diameter stenosis (DS, %), area stenosis (AS, %), minimal lumen diameter (MLD, mm), minimal lumen area (MLA, mm(2)), lesion length (LL, mm), plaque volume (mm(3)) and burden (%). FFR averaged 0.81±0.14, and 10 lesions had an abnormal FFR (<0.75). We found significant correlations between FFR and DS (r=-0.67, p<0.001), AS (r=-0.68, p<0.001), MLD (r=0.58, p<0.001), MLA (r=0.53, p<0.001), LL (r=-0.36, p=0.02), plaque volume (r=-0.36, p=0.02) and plaque burden (r=-0.59, p<0.001). By multivariate regression analysis AS and LL were the strongest determinants of an abnormal FFR. The optimal cut-off value for AS was >73% (sensitivity 90%, specificity 80%, negative predictive value 97%, and positive predictive value 50%) and for LL >10mm (sensitivity 60% and specificity 49%). This study demonstrates that quantitative CCTA is correlated to FFR. Using our CCTA criteria of abnormality, significant coronary artery stenoses can be ruled out with a high negative predictive value.

Prognostic value of transthoracic coronary flow reserve in medically treated patients with proximal left anterior descending artery stenosis of intermediate severity

Prognostic value of transthoracic coronary flow reserve (T-CFR) is not established in patients with left anterior descending artery (LAD) stenosis of intermediate severity. Objective is to determine the prognosis value of T-CFR>2 in medically treated patients with angiographically intermediate [50-70% QCA (quantitative coronary angiography)] proximal LAD stenosis. Among 110 consecutive patients with intermediate LAD stenosis who underwent prospectively T-CFR in the distal part of the LAD after intravenous administration of adenosine to assess the functional significance of the stenosis, 80 patients had T-CFR>2 and were treated medically without revascularization (Group 1). Among the 30 patients who had T-CFR<2, an additional dobutamine stress echocardiography (DSE) was performed: 15 had a negative DSE; were treated medically and served as a comparative group (Group 2), and 15 had a positive DSE; underwent LAD revascularization, and were excluded from further analysis. All patients completed follow-up (16+/-10 months). During the follow-up period (range 6-45 months), 76 patients (95%) remained free of death or LAD-related event in Group 1, vs. 12 patients (80%) in Group 2. By Kaplan-Meier method, at 30 months the per cent estimated survival free from death or target vessel-related events was 92+/-4% in Group 1 and 44+/-22% in Group 2 (P<0.01). By multivariate analysis, T-CFR remained the only independent predictor of death or LAD-related events. In patients with proximal LAD stenosis of intermediate severity and T-CFR>2, deferral of revascularization is associated with low event rate.

Evaluation of Left Anterior Descending Coronary Artery Stenosis of Intermediate Severity Using Transthoracic Coronary Flow Reserve and Dobutamine Stress Echocardiography

The physiologic significance of left anterior descending coronary artery (LAD) stenosis of intermediate angiographic severity is of clinical importance and difficult to assess. Assessment of coronary flow reserve (CFR) by Doppler transthoracic echocardiography (TTE) is a new tool and could allow rapid, noninvasive evaluation of stenosis severity in this setting. We sought to evaluate the value of CFR measurement determined by TTE, compared with dobutamine stress echocardiography (DSE), in the setting of LAD stenosis of intermediate angiographic severity. A total of 51 consecutive stable patients in sinus rhythm (33 men; age 65 +/- 12 years; left ventricular ejection fraction 59 +/- 7%) with no previous anterior myocardial infarction and with an angiographic proximal LAD stenosis of intermediate severity (56 +/- 8% quantitative coronary angioplasty) were prospectively studied. Coronary flow velocity was measured in the distal part of the LAD by TTE at rest and during continuous infusion of 0.14 mg/kg/min of adenosine over 2 minutes, using a multifrequency transducer, in the modified parasternal or 3-apical view. CFR was calculated as the ratio of hyperemic to basal mean (mean CFR) and peak (peak CFR) diastolic flow velocity. DSE was performed immediately after the adenosine test to assess ischemia in the LAD territory (percent maximum predicted heart rate = 94 +/- 8). Adequate recording of CFR was possible in 46 patients. Of the 35 patients with a CFR of 2 or more (peak CFR = 2.7 +/- 0.6), DSE was normal in 34. Of the 11 patients with a CFR less than 2 (peak CFR = 1.7 +/- 0.2), 7 had an abnormal response with DSE in the LAD territory. In this range of intermediate stenosis, there was a poor correlation between percent LAD diameter stenosis and CFR. For patients with positive DSE, CFR was 1.6 +/- 0.2 compared with 2.7 +/- 0.6 for patients with normal DSE (P < .05). The sensitivity, specificity, and the positive and negative predictive values of TTE CFR for detecting ischemia on DSE were 88%, 89%, 64%, and 97%, respectively, with an overall agreement of 89% between the two tests. Given its high negative predictive value, noninvasive CFR could be a useful aid in reaching clinical decisions promptly at the bedside in patients with moderately severe lesions of the proximal LAD.