Accuracy For Detection Of Coronary Artery Disease Research Articles

Exercise induced reduction in myocardial work predicts significant coronary artery disease in patients with false negative stress echocardiography

Abstract Stress echocardiography (SE) is a reliable technique for the diagnosis of coronary artery disease (CAD) with high sensitivity and specificity. However in patients with small left ventricular (LV) cavity caused by marked concentric hypertrophy the sensitivity of SE is low. We assumed that in patients with false negative SE evaluation of global myocardial work (GW) might detect significant CAD. Methods 238 patents with chest pain (98 female, mean age 61±5 years) without history of CAD were referred to SE for CAD confirmation. 94 (39.5%) patients had negative SE and were enrolled in our study for re-examination. Age and gender matched 50 healthy subjects served as controls. GW index (GWI) was obtained from pressure-strain loops composed from speckle tracking analysis indexed to brachial systolic blood pressure. Global constructive work (GCW) as the sum of positive work due to myocardial shortening during systole and negative work due to lengthening during isovolumic relaxation, global wasted work (GWW) as energy loss by myocardial lengthening in systole and shortening in isovolumic relaxation, and GW efficiency (GWE) as the percentage ratio of constructive work to the sum of constructive work and wasted work were measured after submaximal treadmill SE at the heart rate of 100–110 beats per minute (109±11 s after SE) using EchoPac software by blinded experienced echocardiographer. All patients were referred to coronary angiography after re-examination. Results 42 (44.7%) patients had lower GWI values than the lowest limit of GWI value in controls. These patients had significant reduction in GWI, compared with remaining 52 patients in whom GWI did not differ from those of controls (GWI 1897±112 mmHg% vs 2518±243 mmHg%, p<0.01). GCW, GWE and GWW were comparable between patients with or without reduced GWI (GCW 2283±107mmHg% vs 2321±110 mmHg%, p=NS; GWE 96.9±1.1% vs 97.4±1.2%, p=NS; GWW 57±3 mmHg% vs 53±4 mmHg%, p=NS). 28 (66.7%) of 42 patients with GWI reduction and 8 (15.0%) of 52 patients without GWI reduction had at least one vessel significant CAD. GWI had sensitivity, specificity, and accuracy in detection of CAD 78%, 76%, 77% respectively with 67% positive predictive value, and 85% negative predictive value. 29 (80.5%) patients out of 36 with significant CAD had concentric increase in LVMi compared with true negative SE patients (83±6 g/m2 vs 71±4 g/m2, p<0.01). GWI was the predictor of significant CAD (area under the curve 0.793). Conclusion GWI extends diagnostic power of conventional SE in detection of CAD, especially in patients with smaller LV cavity due to concentric hypertrophy when sensitivity of conventional SE is low. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Committee of Sience at Ministry of Education of Republic of Armenia

Long-Term Prognostic Value of Stress Perfusion Cardiovascular Magnetic Resonance Imaging.

The purpose of this review is to analyze the long-term prognostic value of stress perfusion cardiovascular magnetic resonance (CMR) in patients with suspected or known coronary artery disease (CAD). Stress perfusion CMR provides high diagnostic accuracy for detection of CAD, with high sensitivity and relatively lower specificity. A normal stress perfusion CMR examination is highly predictive of overall low patient risk. Conversely, abnormal stress perfusion CMR results are associated with mortality and increased risk for adverse cardiac-related events. Stress perfusion CMR is a useful and robust tool for risk reclassification across different CAD risk categories, and most significant for patients of intermediate risk. Stress CMR is reliable for excluding clinically significant coronary artery disease in patients presenting with low-risk acute chest pain. An ischemic burden threshold of less than 1.5 cardiac segments has been found to be most appropriate for safe deferral from revascularization therapy. A stress perfusion CMR-guided strategy has been shown to be noninferior compared to fractional flow reserve (FFR) for revascularization in patients with stable CAD. In clinical practice, CMR offers a multiplicity of useful techniques besides stress perfusion which may add significant prognostic value when combined with the findings of the stress test itself. Stress perfusion CMR is an accurate noninvasive diagnostic test for patients with suspected CAD and provides strong prognostic value across different risk categories.

Comparative Study between Multislice Computed Tomography Coronary Angiography and Invasive Coronary Angiography in Diagnosis of Mid and Distal Segment Coronary Artery Stenosis

AbstractBackground: Computed Tomography Coronary Angiog-raphy (CCTA) is a promising method for detection and exclu-sion of obstructive coronary artery stenosis. Mid and distal segments of coronary arteries were chosen because they are usually small in caliber especially distal segment (usually less than 1.5mm) and they are affected by cardiac motion on the contrary, the proximal segment is always away from the myocardium and usually larger in diameter so that it can be easily diagnosed by CCTA.Objective: The purpose of this study was to evaluate the added value of CT coronary angiography for detecting Coro-nary Artery Disease (CAD) in mid and distal segment lesions using invasive coronary angiography as a reference standard.Methods: We prospectively evaluated 20 patients who suspected to have CAD and underwent CTA. we assessed mid and distal segment lesions using invasive coronary angiography as a reference standard. We excluded proximal segment lesion, high calcium score (800), arrhythmias, post percutaneous coronary intervention and post coronary artery bypass graft.Results: A total of 20 subjects underwent both CCTA and ICA (60% were females with mean age: 58.1 years). On a patient based model, the sensitivity, specificity, and positive and negative predictive values to detect mid segment lesions were 88.9%, 95.2%, 88.9%, and 95.2% respectively and for distal lesions were 85%, 100%, 100%, 98.1%, respectively. Diagnosis of mid and distal segment lesions by both CT and coronary angiography showed statistically significant strong positive correlation.Conclusion: CT angiography is a reliable tool and has high accuracy for detection of CAD in both mid and distal segment lesions. Importantly, the high NPV (97%) firmly establishes CCTA as an effective noninvasive method to rule out obstructive coronary artery stenosis in patient with mod-erate pre-test probability.

CAD Detection in Patients With Intermediate-High Pre-Test Probability: Low-Dose CT Delayed Enhancement Detects Ischemic Myocardial Scar With Moderate Accuracy But Does Not Improve Performance of a Stress-Rest CT Perfusion Protocol

This study sought to compare computed tomography delayed enhancement (CTDE) against cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) for detection of ischemic scar and to test the additive value of CTDE as part of a comprehensive multidetector computed tomography (MDCT) stress-rest protocol including computed tomography perfusion (CTP) and computed tomography angiography (CTA) for the diagnosis of significant coronary artery disease (CAD). CTDE has been recently described as a promising tool for noninvasive detection of myocardial scar, similarly to CMR-LGE techniques. Despite its theoretical potential as an adjunctive tool to improve MDCT accuracy for detection of CAD, its clinical performance has not been validated. One hundred five symptomatic patients with suspected CAD (age 62.0 ± 8.0 years, 67% men) underwent MDCT, CMR, and x-ray invasive coronary angiography. The MDCT protocol consisted of calcium scoring, stress CTP under adenosine 140 μg/kg/min, rest CTP+ CTA, and a low-dose radiation prospective scan for detection of CTDE. CMR-LGE was used as the reference standard for assessment of scar. Functionally significant CAD was defined as the presence of ≥90% stenosis/occlusion or fractional flow reserve measurements ≤0.80 in vessels >2 mm. CTDE had good accuracy (90%) for ischemic scar detection with low sensitivity (53%) but excellentspecificity (98%). Positive and negative predictive values were 82% and 91%, respectively. On a patient-based model, MDCT protocol without integration of CTDE results had a sensitivity, specificity, and positive and negative predictive values of 90%, 81%, 80%, and 90%, respectively, for the detection of functionally significant CAD. Addition of CTDE results did not improve MDCT performance (90%, 77%, 77%, and 90%, respectively). CTDE has moderate accuracy for detection of ischemic scar in patients with suspected CAD. Integration of CTDE into a comprehensive MDCT protocol including stress-rest CTP and CTA does not improve MDCT accuracy for detection of significant CAD in intermediate-to-high pre-test probability populations.

Dobutamine stress echocardiography in patients undergoing orthotopic liver transplantation: a pooled analysis of accuracy, perioperative and long term cardiovascular prognosis

Pre-transplant evaluation for orthotopic liver transplantation (OLT) commonly includes a cardiac evaluation using dobutamine stress echocardiography (DSE). We performed a quantitative systematic review assessing DSE's use in detecting coronary artery disease (CAD) and predicting perioperative and long term cardiac events in patients undergoing OLT. Published studies in pubmed were accessed using keyword searches and bibliographic review. Included studies evaluated the use of DSE in patients undergoing OLT, including its accuracy for detection of CAD, and in predicting perioperative and long term cardiac prognosis for both hard (myocardial infarction, cardiac death, cardiac arrest, and asystole) and soft cardiac events (all other events that were cardiovascular in nature). We calculated DSE's sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) in the above areas. We identified 7 studies, including a total of 580 patients, which included 4 accuracy studies (n=110 patients), 4 perioperative studies, and 3 long term studies. Accuracy for CAD included a sensitivity of 0.32, specificity of 0.78, PPV of 0.37, and NPV of 0.75. Accuracy for prediction of perioperative hard and soft cardiac events was a sensitivity of 0.20 and 0, specificity of 0.99 and 0.99, PPV of 0.33 and 0, and NPV of 0.98 and 0.89, respectively. For long term hard and soft cardiac events, sensitivity was 0.5 and 0, specificity 0.99 and 0.98, PPV 0.33 and 0, and NPV 0.99 and 0.96, respectively. DSE has a limited accuracy for the detection of CAD in candidates for OLT. However, among those patients selected for OLT, the negative predictive value of DSE for both perioperative and long term cardiac events is high.

Abstract 8702: Assessment of Coronary Artery Disease by Contraction Front Mapping Analysis with Real Time Three-dimensional Stress Echocardiography with Adenosine: A Comparison with Thallium Scintigraphy

Background: Stress echo with adenosine is not routinely used for the assessment of coronary artery disease (CAD) because of insufficient accuracy. Visual estimation of dyssynchrony with 2-D echo is often difficult because delays <70 ms cannot be detected with human eye. Contraction front mapping (CFM) constructed by real time 3-D echocardiography (RT3DE, ACUSON SC2000) with frame rate of 40 fps provides time-volume analysis for left ventricular (LV) volume, and enables us to assess LV dyssynchrony in only one heart beat. Thus, we evaluated usefulness of stress RT3DE for the detection of CAD. Methods : We performed scintigraphy and CFM at rest and stress with adenosine before angiography in 35 patients with suspected CAD. CFM can automatically divide LV into 16 segments, detect dyssynchrony and provide systolic dyssynchrony index (SDI) from the dispersion of time to minimum (min) regional volume for all 16 segments (average SDI) and maximum (max) dispersion of time to min regional volume (max SDI). Coronary angiography was served as a gold standard. Results : Images suitable for analysis were 34 (Figure). Heart rate and LV ejection fraction were increased at stress by 12% and 11% respectively. The prevalence of CAD was 76%. Diagnostic accuracy (88% for echo vs. 87% for scintigraphy), sensitivity (88% vs. 88%) and specificity (88% vs.85%) for the detection of CAD were similar between stress RT3DE and sintigraphy. There was no significant difference in the ability to detect single- or multi-vessel disease between RT3DE and scintigraphy. Although average SDI was similar at rest and at stress (6.6±4.0% vs.7.2±4.0%) max SDI was significantly increased at stress (22±10% vs. 18±8%, p<0.05). Conclusion: CFM constructed by stress RT3DE as a promising technique to quantify LV dyssynchrony in only one heart beat confers similar diagnostic accuracy in detection of CAD to scintigraphy and may be useful in the clinical setting for the evaluation of patients with suspected CAD.

Real-time myocardial perfusion imaging for pharmacologic stress testing: Added value to single photon emission computed tomography

Little is known about the incremental value of real-time myocardial contrast echocardiography (MCE) as an adjunct to pharmacologic stress testing. This study was performed to evaluate the diagnostic value of MCE to detect abnormal myocardial perfusion by technetium Tc 99m sestamibi-single photon emission computed tomography (SPECT) and anatomically significant coronary artery disease (CAD) by angiography. Myocardial contrast echocardiography was performed at rest and during vasodilator stress in consecutive patients (N = 120) undergoing SPECT imaging for known or suspected CAD. Myocardial opacification, wall motion, and tracer uptake were visually analyzed in 12 myocardial segments by 2 pairs of blinded observers. Concordance between the 2 methods was assessed using the kappa statistic. Of 1356 segments, 1025 (76%) were interpretable by MCE, wall motion, and SPECT. Sensitivity of wall motion was 75%, specificity 83%, and accuracy 81% for detecting abnormal myocardial perfusion by SPECT (kappa = 0.53). Myocardial contrast echocardiography and wall motion together yielded significantly higher sensitivity (85% vs 74%, P < .05), specificity of 83%, and accuracy of 85% (kappa = 0.64) for the detection of abnormal myocardial perfusion. In 89 patients who underwent coronary angiography, MCE and wall motion together yielded higher sensitivity (83% vs 64%, P < .05) and accuracy (77% vs 68%, P < .05) but similar specificity (72%) compared with SPECT for the detection of high-grade, stenotic (> or = 75%) coronary lesions. Assessment of myocardial perfusion adds value to conventional stress echocardiography by increasing its sensitivity for the detection of functionally abnormal myocardial perfusion. Myocardial contrast echocardiography and wall motion together provide higher sensitivity and accuracy for detection of CAD compared with SPECT.