Abstract 2688: Can Stress Echocardiography With Tissue Characterization Evaluate Noncritical Coronary Stenosis? A Validation Study Against Simultaneous Measurement of Fractional Flow Reserve

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Tudor Poerner ◽  
Sisi Vilardi ◽  
Björn Goebel ◽  
Hans R Figulla ◽  
Tim Süselbeck

Aim of this study was to evaluate the ability of different echocardiographic modalities to detect myocardial ischemia due to non-critical coronary stenosis, compared to the fractional flow reserve (FFR) as gold standard. Material and Methods: We investigated 22 consecutive patients presenting with stable angina, negative exercise tests and coronary 1-vessel disease with 50–75% diameter stenosis. TDE/SRI was performed at baseline and at peak hyperemia during 0.14 mg/kg/min adenosine infusion simultaneously with intracoronary FFR measurements. Angioplasty was carried out if FFR < 0.75, repeating TDE/SRI during first balloon inflation. Visual wall motion score, peak systolic values for myocardial velocity (Vs), strain rate (SRs), strain (Ss) and peak overall strain (Smax) were determined in the region of interest. Postsystolic shortening (PSS), accepted as typical marker of acute myocardial ischemia, was defined as (Smax-Ss)/Smax > 0.3, with reduced Ss < 15%. Results: Pathologic FFR < 0.75 was found in 11 patients (Table 1 ), who underwent angioplasty. Myocardial contractility reflected by SRs increased during hyperemia only in the patient group with FFR > 0.75 and decreased markedly during balloon inflation. Hyperemic SRs variation correlated with FFR (r = 0.5, p = 0.018) and predicted significantly pathologic FFR with an area under ROC curve of 0.86 (p <0.01). PSS was identified in 10 of 11 patients during vessel occlusion, but had a low sensitivity (2 of 11 patients with FFR < 0.75) for the more subtle changes during hyperemia. Conclusion: Functional assessment of moderate-to-severe coronary stenosis remains a diagnostic challenge. PSS occurrence cannot serve as a reliable noninvasive alternative to FFR. However, the blunted hyperemic variation of systolic strain rate was able to predict a pathologic FFR, even in this small group of patients. Therefore, TDE/SRI emerges as a promising tool to enhance the diagnostic accuracy of adenosine stress echocardiography. Table 1

Author(s):  
Srdjan B. Aleksandric ◽  
Ana D. Djordjevic‐Dikic ◽  
Milan R. Dobric ◽  
Vojislav L. Giga ◽  
Ivan A. Soldatovic ◽  
...  

Background Functional assessment of myocardial bridging (MB) remains clinically challenging because of the dynamic nature of the extravascular coronary compression with a certain degree of intraluminal coronary reduction. The aim of our study was to assess performance and diagnostic value of diastolic‐fractional flow reserve (d‐FFR) during dobutamine provocation versus conventional‐FFR during adenosine provocation with exercise‐induced myocardial ischemia as reference. Methods and Results This prospective study includes 60 symptomatic patients (45 men, mean age 57±9 years) with MB on the left anterior descending artery and systolic compression ≥50% diameter stenosis. Patients were evaluated by exercise stress‐echocardiography test, and both conventional‐FFR and d‐FFR in the distal segment of left anterior descending artery during intravenous infusion of adenosine (140 μg/kg per minute) and dobutamine (10–50 μg/kg per minute), separately. Exercise–stress‐echocardiography test was positive for myocardial ischemia in 19/60 patients (32%). Conventional‐FFR during adenosine and peak dobutamine had similar values (0.84±0.04 versus 0.84±0.06, P =0.852), but d‐FFR during peak dobutamine was significantly lower than d‐FFR during adenosine (0.76±0.08 versus 0.79±0.08, P =0.018). Diastolic‐FFR during peak dobutamine was significantly lower in the exercise‐stress‐echocardiography test –positive group compared with the exercise‐ stress‐echocardiography test –negative group (0.70±0.07 versus 0.79±0.06, P <0.001), but not during adenosine (0.79±0.07 versus 0.78±0.09, P =0.613). Among physiological indices, d‐FFR during peak dobutamine was the only independent predictor of functionally significant MB (odds ratio, 0.870; 95% CI, 0.767–0.986, P =0.03). Receiver‐operating characteristics curve analysis identifies the optimal d‐FFR during peak dobutamine cut‐off ≤0.76 (area under curve, 0.927; 95% CI, 0.833–1.000; P <0.001) with a sensitivity, specificity, and positive and negative predictive value of 95%, 95%, 90%, and 98%, respectively, for identifying MB associated with stress‐induced ischemia. Conclusions Diastolic‐FFR, but not conventional‐FFR, during inotropic stimulation with high‐dose dobutamine, in comparison to vasodilatation with adenosine, provides more reliable functional significance of MB in relation to stress‐induced myocardial ischemia.


Author(s):  
Giovanni Ciccarelli ◽  
Emanuele Barbato ◽  
Bernard De Bruyne

Fractional flow reserve is an index of the physiological significance of a coronary stenosis, defined as the ratio of maximal myocardial blood flow in the presence of the stenosis to the theoretically normal maximal myocardial blood flow (i.e. in the absence of the stenosis). This flow ratio can be calculated from the ratio of distal coronary pressure to central aortic pressure during maximal hyperaemia. More practically, fractional flow reserve indicates to what extent the epicardial segment can be responsible for myocardial ischaemia and, accordingly, fractional flow reserve quantifies the expected perfusion benefit from revascularization by percutaneous coronary intervention. Very limited evidence exists on the role on fractional flow reserve for bypass grafts.


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