Significance Of Coronary Artery Lesions Research Articles

Fractional Flow Reserve Implications for Clinical Decision Making in Coronary Artery Disease.

Fractional flow reserve (FFR) is regarded as the gold standard for assessing the functional significance of coronary artery lesions. However, its utilization in clinical practice remains limited. This study aims to determine whether FFR results can influence treatment decisions for coronary artery disease compared to visual assessments of angiographic images. We conducted a retrospective study involving 63 patients diagnosed with either chronic coronary syndrome (n = 39, 61.9%) or acute coronary syndrome (n = 24, 38.1%) who underwent an FFR assessment. Three experienced interventional cardiologists (>300 PCI procedures/year) reevaluated 105 ambiguous coronary lesions in these patients, blinded to the FFR results. The objective was to assess lesion significance and determine the treatment strategy based on a visual angiographic evaluation. The three operators reached concordant agreement (≥two operators) to perform PCI in 60 (57.1%) of the evaluated lesions based on the angiographic assessment. Of these, nine lesions (15%) were deemed functionally non-significant by FFR (FFR > 0.80). Conversely, they agreed to defer PCI in 45 (42.9%) lesions, but 4 lesions (8.9%) were found to be functionally significant (FFR ≤ 0.80) and required a re-evaluation for PCI. Visual-guided decision making by interventional cardiologists shows variability and does not always align with the functional significance of coronary lesions as determined by FFR. Incorporating FFR into routine decision making could enhance treatment accuracy and patient outcomes.

A Routine Coronary Angiography before Carotid Endarterectomy as an Example of Interdisciplinary Work: The Immediate Results of the Surgery.

The aim: to evaluate the incidence of obstructive lesions of the coronary arteries during routine coronary angiography (CAG) before carotid endarterectomy (CEA) and the incidence of perioperative complications. Materials and Methods: We examined a continuous sample of 498 patients before CEA who underwent an invasive evaluation of the coronary bed during CAG. Depending on the hemodynamic significance of coronary artery lesions, the patients were divided into three groups: group I-obstructive coronary artery disease (≥70%) (n = 309, 62.0%); group II-non-obstructive lesions of the coronary arteries (<70%) (n = 118, 23.7%); group III-intact coronary arteries (n = 71, 14.3%). The groups were compared with each other according to the data of the preoperative examination (clinical and anamnestic parameters, laboratory data and results of echocardiography), as well as according to the immediate results of the operation. In the hospital period, adverse cardiovascular events were assessed: death, myocardial infarction (MI), stroke, arrhythmias, atrial fibrillation or flutter (AF/AFL) and combined endpoint. Results: The groups differed significantly in the presence of symptoms of angina pectoris, myocardial infarction and myocardial revascularization procedures in their medical history and in the presence of chronic ischemia of the lower extremities. However, in the group of intact coronary arteries, the symptoms of angina were in 14.1% of patients, and a history of myocardial infarction was in 12.7%. Myocardial revascularization before CEA or simultaneously with it was performed in 43.0% of patients. As a result, it was possible to reduce the number of perioperative cardiac complications (mortality 0.7%, perioperative myocardial infarction 1.96%). Conclusions: The high incidence of obstructive lesions in the coronary arteries in our patients and the minimum number of perioperative complications favor routine CAG before CEA.

D-5 | FFR and dFR Correlation at a Single Center

Fractional flow reserve (FFR) is used to determine hemodynamic significance of coronary artery lesions. FFR was validated in a prospective, Bayesian approach where the value of 0.75 was identified to be associated with evidence of myocardial ischemia. FFR, which is based on the ratio between mean distal and proximal coronary pressures during the entire cardiac cycle (including systolic). Since estimation of myocardial flow has a linear relationship only during diastole where myocardial resistance is at its minimum.

Clinical Outcomes of Deferred Revascularisation Using Fractional Flow Reserve in Diabetic Patients

BackgroundFractional flow reserve (FFR) is used to assess the functional significance of coronary artery lesions. Diabetic patients are associated with high burden of atherosclerosis and microvascular dysfunction. We studied the clinical outcomes of diabetic patients who underwent FFR-guided deferred revascularisation. MethodsConsecutive patients from a single large volume centre who underwent FFR assessment were included. Clinical endpoints were prospectively collected using the national electronic care records system. The primary endpoint was defined as the four-year risk of the vessel-oriented composite outcome of cardiac death, vessel-related myocardial infarction (VMI), and vessel-related urgent revascularisation (VUR). Absolute FFR values groups (0.81 to 0.85; 0.86 to 0.90; and >0.90) were used to further stratify patient outcomes. ResultsFFR-guided deferred revascularisation occurred in 860 patients (63%), of whom 159 were diabetic. The primary endpoint was significantly higher in the diabetic compared to the non-diabetic group [HR 1.76 (95%CI 1.08 to 2.88), P = 0.024]. The difference was driven from cardiac death (6.3% vs. 3.0%, P = 0.044) and VMI (5.0% vs. 1.7%, P = 0.012) but not VUR (8.8% vs. 5.1%, P = 0.07). There was a significant decrease in the incidence of the primary endpoint in the diabetic group according to FFR groups (23.6%, 12.3%, 2.4%, P = 0.001) with comparable clinical outcomes in the non-diabetic group (11.8%, 6.4%, 7.4%, P = 0.085). ConclusionsOur study demonstrated an increased risk of death and target vessel MI in diabetic patients undergoing FFR-guided deferred revascularisation compared to non-diabetic group. Nonetheless, FFR remained a useful tool to identify those at future risk, mainly in diabetic patients.

Sex Differences in Adenosine-Free Coronary Pressure Indexes: A CONTRAST Substudy

ObjectivesThe goal of this study was to investigate sex differences in adenosine-free coronary pressure indexes. BackgroundSeveral adenosine-free coronary pressure wire indexes have been proposed to assess the functional significance of coronary artery lesions; however, there is a theoretical concern that sex differences may affect diagnostic performance because of differences in resting flow and distal myocardial mass. MethodsIn this CONTRAST (Can Contrast Injection Better Approximate FFR Compared to Pure Resting Physiology?) substudy, contrast fractional flow reserve (cFFR), obtained during contrast-induced submaximal hyperemia, the instantaneous wave-free ratio (iFR), and distal/proximal coronary pressure ratio (Pd/Pa) were compared with fractional flow reserve (FFR) in 547 men and 216 women. Using FFR ≤0.8 as a reference, the diagnostic performance of each index was compared. ResultsMen and women had similar diameter stenosis (p = 0.78), but women were less likely to have FFR ≤0.80 than men (42.5% vs. 51.5%, p = 0.04). Sensitivity was similar among cFFR, iFR, and Pd/Pa when comparing women and men, respectively (cFFR, 77.5% vs. 75.3%; p = 0.69; iFR, 84.9% vs. 79.4%; p = 0.30; Pd/Pa, 78.8% vs. 77.3%; p = 0.78). cFFR was more specific than iFR or Pd/Pa regardless of sex (cFFR, 94.3% vs. 95.8%; p = 0.56; iFR, 75.6% vs. 80.1%; p = 0.38; Pd/Pa, 80.6% vs. 78.7%; p = 0.69). By receiver-operating characteristic curve analysis, cFFR provided better diagnostic accuracy than resting indexes irrespective of sex (p ≤ 0.0001). ConclusionsDespite the theoretical concern, the diagnostic sensitivity and specificity of cFFR, iFR, and Pd/Pa did not differ between the sexes. Irrespective of sex, cFFR provides the best diagnostic performance.

SEX DIFFERENCES AND ADENOSINE FREE CORONARY PRESSURE INDICES: A CONTRAST SUBSTUDY

Several adenosine-free coronary pressure wire indices have been proposed to assess the functional significance of coronary artery lesions. However, there is a theoretical concern that sex differences may affect diagnostic performance due to differences in resting flow. In the CONTRAST (Can Contrast

Diabetes does not impact the diagnostic performance of contrast-based fractional flow reserve: insights from the CONTRAST study

BackgroundAdenosine-free coronary pressure wire metrics have been proposed to test the functional significance of coronary artery lesions, but it is unexplored whether their diagnostic performance might be altered in patients with diabetes.MethodsWe performed a post-hoc analysis of the CONTRAST study, which prospectively enrolled an international cohort of patients undergoing routine fractional flow reserve (FFR) assessment for standard indications. Paired, repeated measurements of all physiology metrics (Pd/Pa, iFR, contrast-based FFR, and FFR) were made. A central core laboratory analyzed blinded pressure tracings in a standardized fashion.ResultsOf 763 subjects enrolled at 12 international centers, 219 (29%) had diabetes. The two groups were well-balanced for age, clinical presentation (stable or unstable), coronary vessel studied, volume and type of intracoronary contrast, and volume of intracoronary adenosine. A binary threshold of cFFR ≤ 0.83 produced an accuracy superior to both Pd/Pa and iFR when compared with FFR ≤ 0.80 in the absence of significant interaction with diabetes status; indeed, accuracy in subgroups of patients with or without diabetes was similar for cFFR (86.7 vs 85.4% respectively; p = 0.76), iFR (84.2 vs 80.0%, p = 0.29) and Pd/Pa (81.3 vs 78.9%, p = 0.55). There was no significant heterogeneity between patients with or without diabetes in terms of sensitivity and specificity of all metrics. The area under the receiver operating characteristic (ROC) curve was largest for cFFR compared with Pd/Pa and iFR which were equivalent (cFFR 0.961 and 0.928; Pd/Pa 0.916 and 0.870; iFR 0.911 and 0.861 in diabetic and non-diabetic patients respectively).ConclusionscFFR provides superior diagnostic performance compared with Pd/Pa or iFR for predicting FFR irrespective of diabetes (clinicaltrials.gov identifier NCT02184117).

INFLUENCE OF LESION LOCATION ON THE DIAGNOSTIC ACCURACY OF ADENOSINE-FREE CORONARY PRESSURE WIRE MEASUREMENTS: THE CONTRAST (CAN CONTRAST INJECTION BETTER APPROXIMATE FFR COMPARED TO PURE RESTING PHYSIOLOGY?) SUBSTUDY

Several adenosine-free coronary pressure wire indices have been proposed to assess the functional significance of coronary artery lesions; however, there is a theoretical concern that lesion location and the amount of myocardium interrogated may affect diagnostic performance. In a total of 763

Abstract 362: Diagnostic Value of Non-invasive Computed Tomography Perfusion Imaging for Assessing Hemodynamically Significant Native Coronary Artery Lesion: A Meta-analysis

Background: Traditionally, hemodynamic significance of a native coronary artery lesion is determined by invasive coronary angiography and fractional flow reserve. Computed tomography perfusion imaging (CTP) is a novel non-invasive method for determining hemodynamic significance of a coronary artery lesion. The objective of our meta-analysis is to determine the diagnostic performance of CTP with and without computed tomography angiography (CTA) in assessment of hemodynamically significant coronary artery lesions in comparison to invasive angiography. Methods: PubMed was searched through December 2014. Nine original studies were found evaluating the diagnostic performance of CTP with and without CTA to invasive coronary angiography in evaluation of hemodynamic significance of coronary lesions (n=951). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and positive and negative likelihood ratios (LR+ and LR- respectively) were calculated using hierarchical summary receiver operating curves and compared with bivariate random-effects model to accommodate for heterogeneity due to study design, population and diagnostic tests. Results: Total of 951 coronary vessels were evaluated for hemodynamically significant lesions. The sensitivity, specificity, PPV, NPV, LR+ and LR- values for CTP with CTA to diagnose hemodynamically significant coronary artery lesions were 83%, 91.7%, 86.4%, 89.4%, 9.94, and 0.19 respectively. The sensitivity, specificity, PPV, NPV, LR+ and LR- values for CTP alone were 82.9%, 84%. 76.1%, 88.9%, 5.18, and 0.20 respectively. The sensitivity, specificity, PPV, NPV, LR+ and LR- values for CTA alone were 89%, 72%, 64.2%, 92.1%, 3.18, and 0.15 respectively (Figure). Conclusion: The results of our meta-analysis assessing diagnostic value of CTP with or without CTA suggest that adding CTA to CTP significantly improves diagnostic performance of hemodynamic significance of coronary artery lesions compared to CTP alone. CTA with CTP is closely comparable with invasive angiography in assessing hemodynamic significance of coronary artery lesions in patients with stable coronary artery disease.

Fractional flow reserve: Current applications and overview of the available data.

Flow fractional reserve (FFR) allows to evaluate the functional significance of coronary artery lesions, through the ratio of the mean coronary artery pressure after the stenosis to the mean aortic pressure during maximum hyperemia. The actual widely accepted cut-off value is 0.80. Below this value a coronary lesion is considered significant and therefore it requires invasive revascularization. Several studies [in particular Fractional Flow Reserve vs Angiography for Multivessel Evaluation 1 (FAME-1) and FAME-2] have shown the relationship between FFR measurement and hard end-points (death, myocardial infarction, and urgent revascularization). Consequently, FFR evaluation represents the cornerstone in the decision-making in intermediate coronary lesions. Recent studies paved the way for further applications of FFR evaluation in complex and tricky clinical settings. In this paper, we perform an overview of the data regarding contemporary application of FFR. In particular, we review the use of FFR in: left main intermediate stenoses, serial stenoses, evaluation after stenting, guidance in coronary artery bypass surgery, and acute coronary syndrome. All the data presented in our overview confirm the essential role of FFR assessment in the daily clinical practice. The shift from "operator-dependent" to "FFR-dependent" evaluation in intermediate coronary artery stenosis is of paramount importance in order to improve the prognosis of our patients, through the discrimination of the functional role of every single coronary stenosis.

CT angiography (CTA) and diagnostic performance of noninvasive fractional flow reserve: results from the Determination of Fractional Flow Reserve by Anatomic CTA (DeFACTO) study.

Fractional flow reserve (FFR) computed from standard coronary CT scans (FFRCT) is a novel noninvasive method for determining the functional significance of coronary artery lesions. Compared with CT alone, FFRCT significantly improves diagnostic accuracy and discrimination for patients with and without hemodynamically significant coronary artery stenoses. To date, the impact of CT image quality on diagnostic performance of FFRCT is unknown. We evaluated the impact of patient preparation, CT scan protocol, and factors related to image quality on the diagnostic accuracy of FFRCT. We studied stable patients with suspected coronary artery disease (CAD), enrolled from 17 centers, who underwent CT, invasive coronary angiography, FFR, and FFRCT. The accuracy of CT and FFRCT for diagnosis of ischemia was compared against an invasive FFR reference standard. Anatomically obstructive CAD was defined by a stenosis value of at least 50 by CT or invasive coronary angiography, whereas ischemia was defined by an FFR or FFRCT of up to 0.80. Ischemia was assessed at the per-patient and per-vessel levels. Diagnostic performance of FFRCT was then evaluated in relation to patient preparation, including administration before CT of a β-blocker or nitroglycerin, as well as in relation to imaging characteristics, including misalignment, noise, motion, and coronary artery calcium. Among 252 study participants, 137 (54.0%) had an abnormal FFR. Administration of a β-blocker increased FFRCT specificity (51.0% vs 66.0%; p = 0.03) with lower bias (-0.084 vs -0.048; p = 0.008), whereas nitroglycerin pretreatment within 30 minutes of CT was associated with improved specificity (54.0% vs 75.0%; p = 0.013). Misalignment artifacts resulted in impaired sensitivity (43.0% vs 86.0%; p = 0.001) with resultant reductions in overall accuracy (56.0% vs 71.0%; p = 0.03). No differences in diagnostic performance of FFRCT were noted in the presence of coronary motion or increasing coronary artery calcium score. Use of β-blockade and nitroglycerin administration before CT improve diagnostic performance of FFRCT. Diagnostic accuracy of FFRCT is significantly reduced in the setting of misalignment artifacts.

Clinical impact of fractional flow reserve in a real-world cohort of patients

Fractional flow reserve (FFR) is an objective method of assessing the functional significance of coronary artery lesions [1–3]. However, FFR is not widely applied in clinical practice. The aims of the study were to study inter-observer differences in visually-guided treatment decisions for coronary artery lesions, and to assess the clinical impact of FFR in the real-world.

Detection of ischaemic myocardial lesions with coronary CT angiography and adenosine-stress dynamic perfusion imaging using a 128-slice dual-source CT: diagnostic performance in comparison with cardiac MRI

We assessed the diagnostic performance of adenosine-stress dynamic CT perfusion (ASDCTP) imaging and coronary CT angiography (CCTA) for the detection of ischaemic myocardial lesions using 128-slice dual-source CT compared with that of 1.5 T cardiac MRI. This prospective study included 33 patients (61±8 years, 82% male) with suspected coronary artery diseases who underwent ASDCTP imaging and adenosine-stress cardiac MRI. Two investigators independently evaluated ASDCTP images in correlation with significant coronary stenosis on CCTA using two different thresholds of 50% and 70% diameter stenosis. Hypoattenuated myocardial lesions on ASDCTP associated with significant coronary stenoses on CCTA were regarded as true perfusion defects. All estimates of diagnostic performance were calculated and compared with those of cardiac MRI. With use of a threshold of 50% diameter stenosis on CCTA, the diagnostic estimates per-myocardial segment were as follows: sensitivity, 81% [95% confidence interval (CI): 70-92%]; specificity, 94% (95% CI: 92-96%); and accuracy 93% (95% CI: 91-95%). With use of a threshold of 70%, the diagnostic estimates were as follows: sensitivity, 48% (95% CI: 34-62%); specificity, 99% (95% CI: 98-100%); and accuracy, 94% (95% CI: 92-96%). Dynamic CTP using 128-slice dual-source CT enables the assessment of the physiological significance of coronary artery lesions with high diagnostic accuracy in patients with clinically suspected coronary artery disease. Combined CCTA and ASDCTP yielded high accuracy in the detection of perfusion defects regardless of the threshold of significant coronary stenosis.

Fractional flow reserve guided revascularization in daily practice: clinical judgment does not always meet science.

Measurement of the fractional flow reserve (FFR) during invasive coronary angiography is the accepted ''gold standard'' for assessing the functional significance of coronary artery lesions by determination of the characteristics of blood flow proximal and distal to a coronary stenosis during pharmacologically-mediated hyperemia. Abnormal FFR is associated with higher cardiac event rate if the coronary lesion is left untreated. On the other hand, it was shown that patients derived no clinical benefit from revascularization of angiographically obstructive lesions which were hemodynamically insignificant according to FFR (>0.8). This editorial comment refers to an observational cohort study which reported that in approximately 20% of real world patients the treatment strategy chosen was discordant with FFR findings. Our comment discusses these findings and concludes that while the standard of care is to treat patients in accordance with their FFR results (when available), it should be recognized that there are some clinical scenarios that may require a treatment strategy that is discordant with FFR result.

Validation of Minimal Luminal Area Measured by Intravascular Ultrasound for Assessment of Functionally Significant Coronary Stenosis: Comparison With Myocardial Perfusion Imaging

This study sought to evaluate the ability of minimal luminal area (MLA) measured by intravascular ultrasound (IVUS) to assess the functional significance of coronary artery disease. The use of IVUS to determine the functional significance of coronary artery lesions remains a matter for debate. From our prospective IVUS imaging database, between July 2009 and April 2010, 170 coronary lesions in 150 patients who underwent stress myocardial single-photon emission computed tomography (SPECT) performed within 1 month of IVUS evaluation were identified and analyzed. MLA and other parameters were measured by IVUS and compared with the results of myocardial SPECT. Overall, 45 lesions had positive SPECT, and 125 lesions had negative SPECT. The MLA of lesions with positive SPECT was smaller than the MLA of those with negative SPECT (1.7 ± 0.5 mm² vs. 2.3 ± 1.1 mm², p < 0.001). By logistic regression analysis, MLA (odds ratio: 3.1 by decrease of 1 mm², 95% confidence interval [CI]: 1.75 to 5.5, p < 0.01) was an independent predictor of the positive SPECT. Using receiver-operator characteristic curve analysis, the best cutoff value of MLA was ≤ 2.1 mm² with an 86.7% sensitivity, a 50.4% specificity, a 38.6% positive predictive value, and a 91.3% negative predictive value versus lesions with a positive SPECT (area under the curve: 0.690, 95% CI: 0.615 to 0.759, p < 0.01). The best cutoff value of MLA measured by IVUS to predict myocardial ischemia was 2.1 mm². The IVUS-measured MLA appeared to play a limited role in detecting functionally significant lesions assessed by myocardial SPECT.

CURRENT APPROACHES TO EVALUATION OF THE MULTIVESSEL CORONARY ATHEROSCLEROSIS IN PATIENTS WITH CHRONIC ISCHEMIC HEART DISEASE

Aim. To determine the validity of stress echocardiography by fractional reserve blood flow (FFR) as the reference method in detection of coronary arteries requiring revascularization, as well as to optimize the determination of the functional significance of coronary artery lesions in patients with multivessel coronary atherosclerosis. Material and methods. Patients (n=36) with stable angina class 2-3 with multivessel coronary atherosclerosis were included into the study. Stress echocardiography with dobutamine or exercise test (treadmill) was performed in all patients. Selective coronary angiography with subsequent evaluation of FFR was carried out in patients with a positive result of stress echocardiography. Totally 108 arteries (87 with stenosing atherosclerosis) were assessed. Results. According to coronary angiography bi-vessel and three-vessel damages were revealed in 21 (58%) and 15 (42%) patients, respectively. Method of stress echocardiography as compared with FFR shown sensitivity — 58%, specificity — 95%, positive predictive value — 87%, positive predictive value of a negative result — 17%. Method of coronary angiography (as a method to detect significant stenosis by visual assessment of coronary artery) as compared with FFR demonstrated sensitivity 100%, specificity — 30%, positive predictive value — 42%. Conclusion. Stress echocardiography for noninvasive patient examination improves the accuracy of determination for the need and extent of revascularization.

Angiographic and physiologic assessment of coronary flow and myocardial perfusion in the cardiac catheterization laboratory

For many years, coronary angiography has been used to define coronary artery lesions. Angiographic assessment of coronary flow using the TIMI flow grade system (TFG) and the TIMI frame count (TFC) methods have played a significant role in our understanding of coronary artery disease and they have proved useful in prediction of long-term clinical outcomes after myocardial infarction. The availability of invasive techniques to assess the physiological significance of coronary artery lesions allows a more rationale approach to the management of patients, particularly those with intermediate lesions. The TIMI scores and other angiographic parameters such as the TIMI myocardial perfusion grade (TMPG) are now integrated into clinical practice, as are the use of flow wires and pressure recording wires. Other angiographic techniques, (e.g. digital subtraction angiography), which at this time are predominantly research tools, will require software integration into the imaging chain to facilitate real-time analysis. In this article, we provide a comprehensive descriptive review of the different means of assessment of coronary flow in the cardiac catheterization laboratory, focusing on scores deducted from angiography as well as invasive haemodynamic measurements of blood flow and pressure.

Integrated Single-Photon Emission Computed Tomography and Computed Tomography Coronary Angiography for the Assessment of Hemodynamically Significant Coronary Artery Lesions

The purpose of this study was to assess the physiologic significance of coronary artery lesions with an integrated single-photon emission computed tomography (SPECT) and computed tomography coronary angiography (CTCA) device. Myocardial perfusion imaging (MPI) with SPECT is of value for assessing the physiologic significance of coronary lesions. Computed tomography coronary angiography is a new technique to noninvasively detect coronary stenosis, with high sensitivity and negative predictive value (NPV) but lower specificity and positive predictive value (PPV). The experimental SPECT/CTCA hybrid imaging device (Infinia gamma camera and LightSpeed16 CT, General Electric, Milwaukee, Wisconsin) enables concurrent assessment of coronary anatomy and myocardial perfusion. Fifty-six patients with angina pectoris underwent single-session SPECT-MPI and CTCA with the hybrid device and coronary angiography (CA) within 4 weeks. The ability of fused SPECT/CTCA images to diagnose physiologically significant lesions showing >50% stenosis and reversible perfusion defects in the same territory was determined and compared with CTCA stand-alone. Of a total of 224 coronary segments in 56 patients, 12 patients and 54 segments (23%) were excluded from further analysis of CTCA. Overall, 170 coronary segments were evaluated. The sensitivity, specificity, PPV, and NPV of CTCA were 96%, 63%, 31%, and 99%, respectively, as compared with 96%, 95%, 77%, and 99%, respectively, for SPECT/CTCA. Hybrid SPECT/CTCA imaging results in improved specificity and PPV to detect hemodynamically significant coronary lesions in patients with chest pain. Single-photon emission computed tomography/CTCA might play a potentially important role in the noninvasive diagnosis of coronary artery disease and introduce an objective decision-making tool for assessing the need for interventions in each occluded vessel.

Coronary Pathophysiology in the Cardiac Catheterization Laboratory

Abstract While Coronary angiography remains the standard for the diagnosis and treatment of coronary artery disease within the cardiac catheterization lab, many lesion subsets require further investigation to determine their overall significance in causing symptoms. Direct measurement coronary flow and subsequently the ability to measure coronary pressure changes at maximal hyperemia have been developed to provide physiologic data to the catheterization operator which reveal the significance of coronary artery lesions in question and guide treatment. These measures, coronary flow reserve (CFR) and fractional flow reserve (FFR) have been validated against non-invasive tests for myocardial ischemia. Furthermore, FFR has also been studied in its ability to guide percutaneous coronary interventions in single vessel disease, multi-vessel disease, ostial side-branch lesions, and left main lesions.

Emerging technology in stress echocardiography.

Stress echocardiography has seen substantial expansion as a clinically useful tool for evaluation of patients with chest pain syndromes, determining the physiological significance of coronary artery lesions and assessing prognosis in patients known to have coronary disease. Several newly developing technologies show promise for enhancing the accuracy and clinical applicability of the examination. These include automatic edge detection systems, intravenous contrast for enhanced endocardial definition, tissue Doppler imaging, and tissue characterization techniques. Finally, new methods of cardiovascular stress, including combinations of exercise and pharmacological agents as well as newly developed pharmacological agents, also show promise for enhancing the clinical utility of stress echocardiography.