scholarly journals 256 Impact of physiologically diffuse vs. focal pattern of coronary disease on quantitative flow reserve diagnostic accuracy

2021 ◽  
Vol 23 (Supplement_G) ◽  
Author(s):  
Roberto Scarsini ◽  
Simone Fezzi ◽  
Gabriele Pesarini ◽  
Paolo Alberto Del Sole ◽  
Concetta Mammone ◽  
...  

Abstract Aims Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) disagree in ∼20% of intermediate coronary lesions. The physiological pattern of disease has a significant influence on FFR-iFR discordance. However, if the pattern of disease (diffuse vs. focal) impacts on QFR accuracy and on its agreement with FFR and iFR remains unknown. Methods and results 194 unselected patients with 224 intermediate coronary lesions were investigated with iFR, FFR and QFR. The physiological pattern of disease was independently assessed with iFR Scout pullback in all the cases by two expert interventional cardiologists who were blinded to the clinical presentation, patient characteristics, coronary angiography and QFR results. A predominantly physiologically focal pattern was observed in 81 (36.2%) lesions, whereas a predominantly physiologically diffuse was observed in 143 (63.8%) cases. QFR demonstrated a significant correlation (r = 0.581, P < 0.001) and a substantial agreement with iFR, both in diffuse (AUC = 0.798) and in focal (AUC = 0.812) pattern of disease. Disagreement between QFR and iFR was observed in 51 (22.8%) lesions, consisting of iFR+/QFR − (64.7%) and iFR−/QFR + (35.3%). Notably, the physiological pattern of disease was the only variable significantly associated with iFR/QFR disagreement. In particular, coronary lesions with iFR+/QFR− demonstrated a significantly higher prevalence of predominantly physiologically diffuse pattern of disease compared with the subgroup with iFR−/QFR + [81.3% (26 of 32) vs. 55.6% (10 of 18); P = 0.012]. QFR virtual pullback demonstrated an excellent agreement (83.9%) with iFR Scout pullback in classifying the physiological pattern of disease. Conclusions QFR has a good diagnostic accuracy in assessing myocardial ischemia independently of the pattern of coronary disease. However, the physiological pattern of disease has an influence on the QFR/IFR disagreement, which occurs in ∼20% of the cases. The QFR virtual pullback correctly defined the physiological pattern of disease in the majority of the cases using the iFR pullback as reference.

Author(s):  
Roberto Scarsini ◽  
Simone Fezzi ◽  
Gabriele Pesarini ◽  
Paolo Alberto Del Sole ◽  
Gabriele Venturi ◽  
...  

Patients suspected of having epicardial coronary disease are often investigated with noninvasive myocardial ischemia tests to establish a diagnosis and guide management. However, the relationship between myocardial ischemia and coronary stenoses is affected by multiple factors, and there is marked biological variation between patients. The ischemic cascade represents the temporal sequence of pathophysiological events that occur after interruption of myocardial oxygen delivery. The earliest part of the cascade is examined via perfusion imaging, and fractional flow reserve (FFR) is a corresponding index which is specific to the coronary artery. Whereas FFR has come to be regarded a clinical reference standard against which other newer invasive and noninvasive tests are validated, the diagnostic FFR threshold for detecting ischemia was established against a combination of noninvasive ischemia tests that assessed different stages of the ischemic cascade. Moreover, the validity of invasive pressure-derived indices of stenosis severity are contingent on the assumption that pressure is proportional to flow if microvascular resistance is constant, a condition induced by pharmacological intervention or by examining specific segments of the cardiac cycle. Furthermore, myocardial perfusion reserve depends on dynamic modulation of microvascular resistance, and dysfunction of the microvasculature can lead to ischemia even in the absence of epicardial coronary disease.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M.R Bigler ◽  
F Praz ◽  
G.C.M Siontis ◽  
M Stoller ◽  
R Grossenbacher ◽  
...  

Abstract Background In patients with chronic coronary syndrome (CCS), percutaneous coronary intervention (PCI) targets hemodynamically significant stenoses, i.e., those thought to cause ischemia. The hemodynamic severity of a coronary stenosis increases with its tightness and with the myocardial mass of viable myocardium downstream of the stenosis. Besides the structural angiographic approach, assessment of functional relevance by pressure measurements (fractional flow reserve, FFR; instantaneous wave-free ratio, iFR) is recommended. However, visual angiographic assessment continues to dominate the treatment decisions for intermediate coronary lesions. Conversely, intracoronary ECG (icECG) potentially provides an inexpensive, sensitive and direct measure of myocardial ischemia. Purpose The goal of this study was to test the accuracy of intracoronary ECG during pharmacologic inotropic stress to determine coronary lesion severity in comparison to established physiologic indices (FFR/iFR) as well as with quantitatively determined percent diameter stenosis (%S) using biplane coronary angiography. Method This was a prospective, open-label study in patients with CCS. The primary study end point was the maximal change in icECG ST-segment shift during pharmacologic inotropic stress induced by dobutamine plus atropine obtained within 1 minute after the point of maximal heart rate (estimated by the formula 220 - age). IcECG was acquired by attaching an alligator clamp to the angioplasty guidewire positioned downstream of a stenosis. For the pressure-derived ratios, i.e. FFR and iFR, the coronary perfusion pressure downstream of a lesion as well as the aortic pressure were continuously recorded. Results One hundred patients were included in the study. Pearson-Correlation coefficient was significant between icECG and all three comparators (%S p<0.001, iFR p<0.001, FFR p<0.001). Using the FFR threshold of 0.80 defining coronary hemodynamic significance, ROC-analysis of the absolute icECG ST-segment shift showed an area under the curve (AUC) of 0.708±0.053 (p=0.0001, n=100, FFR<0.80 n=41). AUC for iFR was 0.919±0.030 (p<0.0001), for percent diameter stenosis it was 0.867±0.036 (p<0.0001). Conclusions During pharmacologic inotropic stress, intracoronary ECG ST-segment shift provides specific evidence for regional myocardial ischemia irrespective of the etiology and thus, provides an additional (patho-)physiologic information for decision making in borderline coronary lesions. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Swiss Heart Foundation


2021 ◽  
Vol 14 (4) ◽  
pp. 486-488
Author(s):  
Hisao Otsuki ◽  
Junichi Yamaguchi ◽  
Junya Matsuura ◽  
Yusuke Inagaki ◽  
Kazuki Tanaka ◽  
...  

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