Comparison of Coronary Computed Tomography Angiography,Fractional Flow Reserve,and Perfusion Imaging for Ischemia Diagnosis

Background

Fractional flow reserve (FFR) computation from coronary computed tomography angiography (CTA) datasets (FFR_CT) has emerged as a promising noninvasive test to assess hemodynamic severity of coronary artery disease (CAD), but has not yet been compared with traditional functional imaging.

Long‐Term Prognostic Significance of Coronary Flow Velocity Reserve in Patients with Significant Coronary Artery Disease Not Involving the Left Anterior Descending Coronary Artery (Results from the SZEGED Study)

Objective: Coronary flow velocity reserve (CFR) by pulsed Doppler echocardiography is a useful hemodynamic index to evaluate the coronary microcirculatory dysfunction in the left anterior descending coronary artery (LAD). The present study was designed to evaluate the long‐term predictive value of CFR for mortality in patients with right (RC) and/or left circumflex coronary artery (CX) stenosis without epicardial LAD disease. Methods: A total of 49 patients with significant RC and/or CX stenosis were enrolled in this prospective follow‐up study. All patients had undergone coronary angiography demonstrating significant RC and/or CX stenosis without LAD disease and dipyridamole stress transoesophageal echocardiography as CFR measurement. Results: The success rate of follow‐up was 43 out of 49 (88%). During a mean follow‐up of 97 ± 29 months, 14 patients suffered cardiovascular deaths (12 sudden cardiac deaths and 2 strokes), and 1 patient died of pulmonal tumor. Patients who died during the follow‐up had significantly lower CFR values (1.85 ± 0.43 vs. 2.31 ± 0.57, P < 0.05). Using ROC analysis, CFR <2.09 had the highest accuracy in predicting cardiovascular survival (sensitivity 80%, specificity 57%, area under the curve 73%, P = 0.003). The logistic regression model identified only CFR as an independent predictor of survival (hazard ratio [HR] 6.26, 95% CI of HR 1.23–19.61, P = 0.024). Conclusions: Long‐term prognostic significance of CFR for the prediction of mortality has been demonstrated during a 9‐year follow‐up in patients with significant coronary artery disease not involving the LAD. (Echocardiography 2010;27:306‐310)     

Short-Term Results and Intermediate-Term Follow-Up of Laser Wire Recanalization of Chronic Coronary Artery Occlusions: A Single-Center Experience

Objectives. This study sought to elucidate the short-term efficacy and intermediate-term outcome of excimer laser recanalization of chronic coronary artery occlusions in patients in whom attempts at mechanical revascularization had failed.

Background. Recanalization of chronic coronary occlusions with the use of a mechanical guide wire fails in 30% to 50% of cases, mostly because of inability to pass the wire through the lesion. The value of using excimer laser energy in this setting has not yet been determined.

Methods. The study group comprised 66 consecutive patients with 68 chronic coronary occlusions. Patients were eligible for inclusion in the study if a previous attempt at mechanical revascularization had failed and if their angiographic status was such that 1) the vessel segment distal to the occlusion could be visualized by way of collateral vessels, 2) the entry point of the occlusion was clearly outlined, and 3) not more than one anatomic bend was expected within the occlusion. Excimer laser energy was applied to the lesion through a 0.018-in. (0.046 cm) fiber-optic guide wire. Adjunctive balloon angioplasty and stenting were performed in all successfully treated patients but one.

Results. Thirty-four occlusions (50%) in 32 patients (48%) could be crossed with the laser wire. Location and age of the occlusion had no adverse influence on the outcome of laser wire recanalization, nor did the presence of bridging collateral vessels, a major side branch at the site of the lesion or a blunt stump of the occlusion. An inverse relation was found between the success rate and the length of the occlusion, such that a 19% reduction of the success rate accompanied each 10-mm increment of the mean occlusion length. Thus, the success rate was 68% for lesions ≤10 mm but only 25% for lesions >30 to ≤40 mm. The presence of a bend in the lesion exceeding 60° was strongly related to procedural failure. During a median angiographic follow-up period of 18 weeks, restenosis >50% (n = 6) or reocclusion (n = 4) was found in 10 of the 32 successfully treated patients, for an intermediate-term success rate of 33% (22 of 66). Clinical follow-up revealed improved anginal status in 21 patients (66%) after a median of 24 weeks. Major complications (death, myocardial infarction, emergency operation) were not encountered.

Conclusions. Successful recanalization of a chronic coronary occlusion by using currently available laser wires can be expected in 50% of selected patients in whom attempts at mechanical revascularization fail. Restenosis or reocclusion accounts for an overall 6-month success rate of 35%.     

The Impact of Downstream Coronary Stenosis on Fractional Flow Reserve Assessment of Intermediate Left Main Coronary Artery Disease: Human Validation

ObjectivesThe aim of this study was to determine the impact of downstream coronary stenosis in the left anterior descending coronary artery (LAD) or left circumflex coronary artery (LCx) on the assessment of fractional flow reserve (FFR) across an intermediate left main coronary artery (LMCA) stenosis in humans with the pressure wire positioned in the nondiseased downstream vessel.BackgroundAccurate assessment of intermediate LMCA disease is critical for guiding decisions regarding revascularization. In theory, FFR across an intermediate LMCA stenosis will be affected by downstream disease, even if the pressure wire is positioned in the nondiseased downstream vessel.MethodsAfter percutaneous coronary intervention of the LAD, LCx, or both, an intermediate LMCA stenosis was created with a deflated balloon catheter. FFR was measured in the LAD and LCx coronary arteries before and after creation of downstream stenosis by inflating an angioplasty balloon within the newly placed stent. The true FFR (FFR_true) of the LMCA, measured in the nondiseased downstream vessel in the absence of stenosis in the other vessel, was compared with the apparent FFR (FFR_app) measured in the presence of stenosis.ResultsIn 25 patients, 91 pairs of measurements were made, 71 with LAD stenosis and 20 with LCx stenosis. FFR_true of the LMCA was significantly lower than FFR_app (0.81 ± 0.08 vs. 0.83 ± 0.08, p < 0.001), although the numerical difference was small. This difference correlated with the severity of the downstream disease (r = 0.35, p < 0.001). In all cases in which FFR_app was >0.85, FFR_true was >0.80.ConclusionsIn most cases, downstream disease does not have a clinically significant impact on the assessment of FFR across an intermediate LMCA stenosis with the pressure wire positioned in the nondiseased vessel.     

冠状动脉计算机体层成像血管造影在冠状动脉疾病的临床应用

冠状动脉计算机体层成像血管造影是诊断冠状动脉疾病的一个优秀无创评价测试工具。虽然冠状动脉造影是冠状动脉粥样硬化性心脏病的金标准,但有充分的证据来支持冠状动脉计算机体层成像血管造影的性价比,而且它的临床应用范围广。本次综述的目的是对冠状动脉计算机体层成像血管造影在冠状动脉疾病临床应用中的诊断准确性和预测价值的概述;对冠状动脉计算机体层成像血管造影的新兴领域,包括双源计算机体层成像、多排螺旋计算机体层成像进行讨论,以及冠状动脉计算机体层成像血管造影的局限性和突出展示其未来的发展方向。     

The Additive Diagnostic Role of Coronary Flow Reserve in Noninvasive Evaluation of Coronary Stenosis on Left Descending Artery Previously Detected by Multislice Computed Tomography

Purpose: Multislice computed coronary angiography (MSCT) provides valuable morphological information about coronary artery disease, but precise quantification of coronary stenosis remains difficult. Transthoracic color Doppler echocardiography (TDE) gives a new insight into the functional significance of coronary luminal narrowing. We have tried to assess the additive value of coronary flow reserve (CFR) determined by TDE over MSCT in prediction of a significant stenosis on the left anterior descending artery (LAD) using the invasive coronary angiography (ICA) as a reference method. Methods: This prospective study included 63 patients in stable cardiac status with previously detected atherosclerotic lesions on LAD by MSCT. CFR assessment by TDE with adenosine infusion was obtained to all patients (feasibility was 96.92%). CFR was determined as ratio between the peak diastolic flow velocity during adenosine infusion and at basal condition, a cutoff value indicating significant stenosis was <2. ICA was preformed to all patients 24–48 hours after CFR. Results: MSCT had sensitivity of 86.36%, specificity 53.66%, positive predictive value 50.00%, negative predictive value 88.00%, and diagnostic accuracy of 65.07% in detection of significant LAD stenosis. CFR had sensitivity 81.81%, specificity 97.06%, positive predictive value 94.74%, negative predictive value 89.19%, and diagnostic accuracy of 91.07%. When the results of both methods were agreed diagnostic accuracy was improved to 92.72%. Conclusion: Additional assessment of CFR by TDE increase diagnostic accuracy of MSCT angiography in detection of significant coronary artery lesions.     

Prospective Comparison of FFR Derived From Coronary CT Angiography With SPECT Perfusion Imaging in Stable Coronary Artery Disease: The ReASSESS Study

Objectives

This study sought to compare the per-patient diagnostic performance of coronary computed tomography angiography (CTA)-derived fractional flow reserve (FFR_CT) with that of single-photon emission computed tomography (SPECT), using a fractional flow reserve (FFR) value of ≤0.80 as the reference for diagnosing at least 1 hemodynamically significant stenosis in a head-to-head comparison of patients with intermediate coronary stenosis as determined by coronary CTA.

A Novel Technique in the Use of Fractional Flow Reserve in Coronary Artery Bifurcation Lesions

The side branch (SB) in bifurcation lesions is a frequently encountered challenge that interventional cardiologists must face. There is great interest in determining fractional flow reserve (FFR) in the SB to help guide treatment decisions; however, difficulty with the pressure guidewire limits its widespread use. We propose a novel technique that will ease the incorporation of FFR in routine evaluation of bifurcation lesions, and allow better assessment of provisional stenting and need for SB intervention. Conventionally, to measure SB FFR, the jailed SB is re-crossed through the stent strut using a pressure wire. Our technique involves the use of a microcatheter and wire exchange within the SB, thereby alleviating some of the technical difficulties associated with the FFR wire. In light of the difficulties and clinical concerns associated with bifurcation lesions, we propose an innovative method to ease the incorporation of FFR to allow better assessment of provisional stenting and need for SB intervention.     

Diagnostic Value of Transluminal Attenuation Gradient for the Presence of Ischemia as Defined by Fractional Flow Reserve and Quantitative Positron Emission Tomography

Objectives

The aim of this study was to investigate the incremental diagnostic value of transluminal attenuation gradient (TAG), TAG with corrected contrast opacification (TAG-CCO), and transluminal diameter gradient (TDG) over coronary computed tomography angiography (CTA)–derived diameter stenosis alone for the identification of ischemia as defined by both the invasive reference standard fractional flow reserve (FFR) and the noninvasive reference standard quantitative positron emission tomography (PET).

Coronary Atherosclerotic Precursors of Acute Coronary Syndromes

Background

The association of atherosclerotic features with first acute coronary syndromes (ACS) has not accounted for plaque burden.