Diagnosis Of Coronary Artery Stenosis Research Articles

Tissue Doppler echocardiography improves the diagnosis of coronary artery stenosis in stable angina pectoris

Aim To determine if colour tissue Doppler imaging (TDI) performed at rest in patients with suspected stable angina pectoris (SAP) is able to predict the presence of significant coronary artery disease (CAD). This study comprises 296 consecutive patients with clinically suspected SAP, no previous cardiac history, and a normal ejection fraction. All patients were examined by colour TDI, exercise electrocardiogram (ECG), and coronary angiography (CAG). Regional longitudinal systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities were measured by colour TDI at six mitral annular sites and averaged to provide global estimates. Duke score (DS), including ST depression, chest pain, and exercise capacity, was used as the outcome of the exercise ECG. Patients with an area stenosis of ≥70% in at least one epicardial coronary artery were categorized as having a significant CAD (n= 108) and were compared with patients without significant CAD (n= 188). Both e' [odds ratio (OR): 1.5 (1.1-1.9, P < 0.01) per cm/s decrease] and s' [OR: 1.7 (1.1-2.5, P < 0.05) per cm/s decrease] remained independent predictors of CAD after multivariable adjustment for baseline, exercise ECG, and conventional echocardiographic parameters. Area under the receiver operating characteristic curve (AUC) for exercise ECG and TDI in combination was significantly higher than AUC for exercise ECG alone (0.84 vs. 0.79, P < 0.01). In patients with suspected SAP colour TDI performed at rest is an independent predictor of significant CAD, and colour TDI improves the diagnostic performance of exercise ECG.

Preliminary study of whole-heart coronary MR angiography in the diagnosis of coronary artery stenosis on 1.5 T

MRI是冠状动脉无创性检查手段之一.早期采用双斜靶容积定位法进行分段采集,因定位复杂、不易推广.全心冠状动脉MR成像(whole-heart coronary magnetic resonance angiography,WH CMRA)克服了定位复杂的缺点,但其诊断冠状动脉狭窄的准确性国内报道较少.笔者结合47例患者资料,评价WH CMRA在诊断冠状动脉狭窄方面的价值和限度。

Diagnostic accuracy of dual-source CT coronary angiography: The effect of average heart rate, heart rate variability, and calcium score in a clinical perspective

Dual-source CT coronary angiography (CTCA) has been used to detect coronary artery disease; however, the factors with potential to affect its diagnostic accuracy remain to be defined. To prospectively evaluate the accuracy of dual-source CTCA in diagnosing coronary artery stenosis according to conventional coronary angiography (CAG), and the effect of average heart rate, heart rate variability, and calcium score on the accuracy of CTCA. A total of 113 patients underwent both dual-source CTCA and CAG. The results were used to evaluate the findings in dual-source CTCA to assess the accuracy in the diagnosis of > or =50% (significant stenosis) and >75% (severe stenosis) of coronary artery according to those by CAG. Patients were divided into subgroups according to their heart rate (HR), HR variability (HRV), and calcium score, and the accuracy of CTCA was further evaluated. The chi-square test was used to analyze the difference in sensitivity and specificity for the detection of > or =50% and >75% coronary stenosis among subgroups. The generalized estimation equation method was used in per-vessel analysis to adjust for within-patient correlation. In all, 113 patients had 338 vessels and 1661 segments evaluated by CAG. Dual-source CTCA displayed 1527 segments (91.9%). Among them, 1468 segments (calcium score by CAG score 1, n=1018; score 2, n=270; score 3, n=180) were assessable in CTCA. On a per-patient analysis, the sensitivity and specificity of CTCA were 93.9% and 93.5% for significant stenosis and 86.9% and 98.1% for severe stenosis. On a per-vessel basis, the sensitivity and specificity were 90.2% and 97.1% for significant and 83.3% and 98.1% for severe stenosis. On a per-segment analysis, the sensitivity and specificity were 90.2% and 97.1% for significant and 83.3% and 98.1% for severe stenosis. Average HR had no effect on the sensitivity and specificity of CTCA (P>0.05); whereas HRV and calcium score had some effect on the sensitivity and specificity of CTCA (P<0.05). On a per-patient, per-vessel, and per-segment basis, dual-source CTCA has a high sensitivity and specificity for the diagnosis of coronary artery stenosis. Average HR has no effect on the diagnostic accuracy of CTCA, while HRV and calcium score have a statistically significant effect on the sensitivity and specificity of CTCA.

Developments in hybrid scanning

Image registration has long been a vital tool in medical imaging, and nuclear cardiology is no exception. Frequently, more than one imaging procedure is used during evaluation of patients for cardiac disease. Coronary angiography is the gold standard for diagnosis of coronary artery stenosis; magnetic resonance imaging (MRI) is performed to determine gross anatomy and function, and single-photon emission computed tomography (SPECT) or positron emission computed tomography (PET) is used to evaluate myocardial perfusion. More recently coronary multislice CT has been added to the armentarium providing the opportunity for noninvasive coronary angiography and detection of coronary artery calcification. Knowing the coronary anatomy is not enough to decide the culprit lesion in the treatment of ischaemic heart disease. Knowledge of the physiology of the coronary artery disease by functional studies like PET and SPECT is crucial. Both anatomical and functional data are equally important. There is no doubt that the combination of the two modalities allow better decision making and an improved final outcome for the patient. Comparison of biplane angiography with myocardial perfusion SPECT and PET images has been a routine practice in reading rooms and cardiology offices since the introduction of the techniques. Countless conferences have been held where physicians debate how the findings of these two modalities relate to each other in individual patients. However, a significant difficulty has been that most of the registration occurred in the minds of physicians as they look at two separate images. In order to solve this problem integrated scanners have developed

Multiple center studyabout the reliability of the low-dose dual-source CT coronary angiography in thestep-and-shoot mode

：Objective To investigatethe accuracy of low-dose dual-source computed tomography (DSCT) coronary angiography inthe step-and-shoot (SAS) mode for the diagnosis of coronary artery stenosis in comparisonwith conventional coronary angingraphy (CCA).Methods Prospective multiple-center study, 46patients[mean age(58±9) years;bedy mass index(BMI) (25±3) kg/m2]underwent both DSCT inthe SAS mode and CCA within 14 days.The inclusion criteria for contrast-enhanced CT: (1)heart rate less than 65 times/rain (bpm).(2) regular sinus rhythm, heart rate fluctuationswithin the range of 6 bpm. (3) holding breath well, breath-hold time is about 12-15 s.Theexclusion criteria:(1) allergy to iodinecontaining contrast medium, nephropathy (serumcreatinine level 120 μmol/L), heart failure and serious arrhythmias.(2) patients with coronary stentsor bypass grafts.(3) heart rate can not be controlled very well (4)the patient could nottake nitroglycerin.(5)BMI 30 kg/m2.(6) other heart disease: carcliomyopathy, valvulardisease etc.Sensitivity, specificity, negative (NPV) and positive predictive value (PPV)were determined with CCA as standard of reference.The Kappa value between the twomodalities and the two observers was calculated.Radiation dose values weremeasured.Results Mean heart rate during scanning was (61±6)bpm.99.19% (614/619) coronarysegments were depicted with a diagnostic image quality. The vessel-based sensitivity,specificity, PPV, and NPV for the diagnosis of coronary artery stenosis were 96.2%(75/78), 88.2% (60/68), 90.4% (75/83), and 95.2% (60/63), respectively.The Kappa valuebetween the two modalities was 0.848 (P=0.000).The mean effective dose of the SAS-CTCA was(2.95± 0.96) rosy(1.26-4.32 mSy).Conclusion In selected patients, DSCT coronaryangiography in the SAS mode have good image quality, which allows for the accuratediagnosis of coronary stenosis at a low radiation dose. Key words: Radiation dosage; Tomography, X-ray computed; Coronaryangiography

Screening strategies for the diagnosis of coronary artery stenosis in patients with cerebral infarction using dual-source spiral CT

This study was to evaluate the benefit of the screening of coronary artery stenosis (CAS) using dual-source CT (DSCT) in patients with cerebral infarction caused by a Large Artery Atherosclerosis (LAA). From November 2007 to February 2008, 34 patients (25 males and 9 females; mean age, 62.4±9.5 years) were enrolled. All of them had ischemic strokes of LAA type but with no cardiac symptoms. All patients underwent coronary CT angiography (CCTA) using DSCT. A significant coronary artery stenosis was defined as the one having more than 50% of luminal narrowing. We evaluated diagnostic accuracy for CAS in stroke patients of LAA with a receiver operating characteristics curve analysis. Of the 34 ischemic stroke patients, 18 (52.9%) had normal coronary arteries, 5 (14.7%) had insignificant CAS, and 11 (32.4%) had a significant CAS. The Agatston scores were more than 400 in 54.5% of the patients with a significant CAS, but less than 40 in 86.9% of the patients without it (p for trend=0.001). For age, the optimal cut-off point for a diagnosis of CAS was 63, which had a sensitivity of 90.9%, a specificity of 69.6%, a positive predictive value of 58.8%, and a negative predictive value of 94.1%, respectively. For the Agatston score, the optimal cut-off was 40, which had 81.8%, 91.3%, 81.8%, and 91.3%, respectively. CCTA using DSCT appears to be a promising screening technique for CAS in patients with an ischemic stroke of LAA.

Non-Stress Echocardiographic Diagnosis of Coronary Artery Stenosis

Non-Stress Echocardiographic Diagnosis of Coronary Artery Stenosis

The first second-generation adenosine drug enters the US market

On 10 April 2008, CV Therapeutics, Inc. of Palo Alto, California, USA, received approval from the US Food and Drug Administration (FDA) for the use of Lexiscan® (regadenoson; CVT-3146), an A2A adenosine receptor (A2AAdoR) agonist, as a pharmacological stress agent in conjunction with radionuclide myocardial perfusion imaging (MPI) in patients unable to undergo adequate exercise stress. Lexiscan® has a higher affinity for A2A adenosine receptors than adenosine and is a more potent coronary vasodilator. It preferentially dilates coronary arteries relative to other vascular beds [1], probably due to the high density of A2AAdoR in the coronary arteries and high receptor reserve at that site [2], resulting in maximal vasodilation induced by the activation of a small percentage of these receptors. MPI is commonly used in the clinical setting for the diagnosis of coronary artery stenosis. The rationale for the use of pharmacologic vasodilators in MPI is based on the differential blood flow response in normal vs. diseased coronary arteries, resulting in a coronary-steal phenomenon. The production of myocardial perfusion defects is reflected in nonhomogeneous distribution of a radiopharmaceutical, which is administered subsequent to the vasodilator agent, detected by a gamma camera, and quantified by a computer utilizing specific software. Adenosine and dipyridamole (an adenosine transport blocker that elevates extracellular adenosine levels) have previously been used as pharmacologic stressors; however, the use of both is associated with adverse effects caused by the activation of A1AdoR in addition to the A2AAdoR. For example, first-degree atrioventricular (AV) block occurs in approximately 10% and second- or third-degree AV block in approximately 4% of patients due to the inhibitory effect of adenosine on the AV nodal conduction [3]. Lexiscan® (Fig. 1), given as a bolus injection, increases coronary blood flow velocity by more than 2.5-fold above baseline for at least 2 min [4], which is ample time for the administration and distribution of a radiopharmaceutical. Fig. 1 Lexiscan® (CVT-3146): Adenosine, 2-[4-[(methylamino)carbonyl]-1H-pyrazol-1-yl]-, monohydrate Experience with regadenoson (Lexiscan®) has shown that it is well-tolerated, as effective as adenosine as a pharmacologic stressor in MPI, and associated with less side effects than adenosine [5]. Lexiscan® is approved 19 and 13 years after the approval of Adenocard® (intravenous adenosine) in 1989 for conversion of paroxysmal supraventricular tachycardia (PSVT) to sinus rhythm and Adenoscan® in 1995 as a pharmacological stress agent in MPI, respectively. The approval of Lexiscan® represents an important milestone in the adenosine research field. It is the first synthetic adenosine receptor ligand approved for medical use. The approval should serve as an impetus for the development of others adenosine and purine nucleotide analogs as novel diagnostic and therapeutic agents.

Comparison of Transaxial Source Images and 3-Plane, Thin-Slab Maximal Intensity Projection Images for the Diagnosis of Coronary Artery Stenosis with Using ECG-Gated Cardiac CT

ObjectiveWe wanted to compare the transaxial source images with the optimized three plane, thin-slab maximum intensity projection (MIP) images from electrocardiographic (ECG)-gated cardiac CT for their ability to detect hemodynamically significant stenosis (HSS), and we did this by means of performing a receiver operating characteristic (ROC) analysis.Materials and MethodsTwenty-eight patients with a heart rate less than 66 beats per minute and who were undergoing both retrospective ECG-gated cardiac CT and conventional coronary angiography were included in this study. The contrast-enhanced CT scans were obtained with a collimation of 16×0.75-mm and a rotation time of 420 msec. The transaxial images were reconstructed at the mid-diastolic phase with a 1-mm slice thickness and a 0.5-mm increment. Using the transaxial images, the slab MIP images were created with a 4-mm thickness and a 2-mm increment, and they covered the entire heart in the horizontal long axis (4 chamber view), in the vertical long axis (2 chamber view) and in the short axis. The transaxial images and MIP images were independently evaluated for their ability to detect HSS. Conventional coronary angiograms of the same study group served as the standard of reference. Four radiologists were requested to rank each image with using a five-point scale (1 = definitely negative, 2 = probably negative, 3 = indeterminate, 4 = probably positive, and 5 = definitely positive) for the presence of HSS; the data were then interpreted using ROC analysis.ResultsThere was no statistical difference in the area under the ROC curve between transaxial images and MIP images for the detection of HSS (0.8375 and 0.8708, respectively; p > 0.05). The mean reading time for the transaxial source images and the MIP images was 116 and 126.5 minutes, respectively.ConclusionThe diagnostic performance of the MIP images for detecting HSS of the coronary arteries is acceptable and this technique's ability to detect HSS is comparable to that of the transaxial source images.

Pitfalls in 16–Detector Row CT of the Coronary Arteries

Recently developed 16-detector row computed tomography (CT) has been introduced as a reliable noninvasive imaging modality for evaluating the coronary arteries. In most cases, with appropriate premedication that includes beta-blockers and nitroglycerin, ideal data sets can be acquired from which to obtain excellent-quality coronary CT angiograms, most often with multiplanar reformation, thin-slab maximum intensity projection, and volume rendering. However, various artifacts associated with data creation and reformation, postprocessing methods, and image interpretation can hamper accurate diagnosis. These artifacts can be related to pulsation (nonassessable segments, pseudostenosis) as well as rhythm disorders, respiratory issues, partial volume averaging effect, high-attenuation entities, inappropriate scan pitch, contrast material enhancement, and patient body habitus. Some artifacts have already been resolved with technical advances, whereas others represent partially inherent limitations of coronary CT angiography. Familiarity with the pitfalls of coronary angiography with 16-detector row CT, coupled with the knowledge of both the normal anatomy and anatomic variants of the coronary arteries, can almost always help radiologists avoid interpretive errors in the diagnosis of coronary artery stenosis.

Combined coronary and perfusion cardiovascular magnetic resonance for the assessment of coronary artery stenosis.

The purpose of this study was to evaluate the feasibility and accuracy of combined coronary and perfusion cardiovascular magnetic resonance (CMR) in the assessment of coronary artery stenosis. Thirty-five consecutive patients (27 men, eight women, age range 34-81 years), undergoing cardiac catheterization, were assessed with 3D coronary CMR and rest-stress perfusion CMR. Significant coronary stenosis was determined by vessel narrowing or signal loss with coronary CMR, and by abnormal contrast enhancement with perfusion CMR. Coronary artery diameter stenosis greater than 50% was considered significant with conventional cardiac catheterization. Seventeen patients had significant coronary artery disease, and in these there were 35 significant stenoses on cardiac catheterization. All left main stem arteries were normal on both cardiac catheterization and coronary CMR. For the diagnosis of coronary artery stenosis, coronary CMR had a sensitivity of 92% for the left anterior descending artery (LAD), 79% for the right coronary artery (RCA), but only 13% for the circumflex coronary artery (LCX). Perfusion CMR had corresponding sensitivities of 69%, 86%, and 63%, respectively. For all arteries the accuracies for coronary and perfusion CMR were 67% and 72%, respectively. Combining coronary and perfusion CMR improved the accuracy to 77%. These data demonstrate that in patients with suspected coronary artery disease, combined coronary and perfusion CMR is feasible, increases the accuracy of detection of significant coronary stenosis, and offers the possibility of combined anatomical and hemodynamic assessment of coronary artery stenosis.

The Combined Use of Adenosine Stress Echocardiography and Myocardial Perfusion Imaging for Diagnosis of Coronary Artery Stenosis in Angina Patients

The Combined Use of Adenosine Stress Echocardiography and Myocardial Perfusion Imaging for Diagnosis of Coronary Artery Stenosis in Angina Patients

Color-coded curved anatomical M-mode analysis of contrast echocardiography: a novel technique for the diagnosis of coronary artery stenosis

Color-coded curved anatomical M-mode analysis of contrast echocardiography: a novel technique for the diagnosis of coronary artery stenosis

Noninvasive Diagnosis of Coronary Artery Stenosis in Women with Limited Exercise Capacity: Comparison of Dobutamine Stress Echocardiography and 99mTc Sestamibi Single-Photon Emission CT

To compare the accuracy of dobutamine stress echocardiography (DSE) and simultaneous 99mTc sestamibi (MIBI) single-photon emission CT (SPECT) imaging for the diagnosis of coronary artery stenosis in women. Seventy women with limited exercise capacity referred for evaluation of myocardial ischemia. DSE (up to 40 microg/kg/min) was performed in conjunction with stress MIBI SPECT. Resting MIBI images were acquired 24 h after the stress test. Ischemia was defined as new or worsened wall motion abnormalities confirmed by DSE and as reversible perfusion defects confirmed by MIBI. Significant coronary artery disease was defined as > or = 50% luminal diameter stenosis. DSE was positive for ischemia in 35 of 45 patients with coronary artery stenosis and in 2 of 25 patients without coronary artery stenosis (sensitivity = 78% CI, 68 to 88; specificity = 92% CI, 85 to 99; and accuracy = 83% CI, 74 to 92). A positive MIBI study for ischemia occurred in 29 patients with coronary artery stenosis and in 7 patients without coronary artery stenosis (sensitivity = 64% CI, 53 to 76; specificity = 72% CI, 61 to 83; and accuracy = 67% CI, 56 to 78 [p < 0.05 vs DSE]). In the 59 vascular regions with coronary artery stenosis, the regional sensitivity of DSE was higher than MIBI (69% CI, 62 to 77 vs 51% CI, 42 to 59, p < 0.05), whereas specificity in the 81 vascular regions without significant stenosis was similar (89% CI, 84 to 94 vs 88% CI, 82 to 93, respectively). DSE is a useful noninvasive method for the diagnosis of coronary artery stenosis in women and provides a higher overall and regional diagnostic accuracy than dobutamine MIBI SPECT in this particular population.

Accuracy of dobutamine stress echocardiography for the diagnosis of coronary artery stenosis in patients with myocardial infarction: the impact of extent and severity of left ventricular dysfunction.

To assess the value of dobutamine stress echocardiography (DSE) in the prediction of the extent and location of coronary artery stenosis in symptomatic patients with old myocardial infarction and to study the impact of the severity of resting wall motion abnormalities (WMA) on the diagnostic accuracy of the test. One hundred and thirty two symptomatic patients with old myocardial infarction. DSE (up to 40 micrograms/kg/min, with atropine up to 1 mg) was performed in all patients. Ischaemia was defined as new or worsened WMA. For each coronary artery, regional wall motion in the corresponding territory was classified as normal, mildly, moderately, or severely impaired according to the wall motion score index. Significant coronary stenosis was defined as > or = 50% diameter stenosis. A positive DSE for ischaemia occurred in 87 of 111 patients with and three of 21 patients without coronary artery stenosis (sensitivity = 78%; CI 71 to 86, specificity = 86%; CI 79 to 92, accuracy = 80%; CI 73 to 87). The accuracy for the diagnosis of individual coronary stenosis was 69% in the presence of normal wall motion and 74%, 74%, and 61% respectively when there was mild, moderate, and severe WMA in the corresponding territories (P = NS). The sensitivity was higher in presence of mild or moderate WMA (73%) than with normal wall motion (53%) or severe WMA (56%, P < 0.05 in both). In territories subtended by a stenotic artery, the regional wall motion score index was not different with or without ischaemia. DSE had a good overall accuracy for the diagnosis of coronary artery stenosis in symptomatic patients with old myocardial infarction. The presence of resting WMA did not limit DSE as a method of eliciting myocardial ischaemia and diagnosing significant coronary artery stenosis in patients with old myocardial infarctions.

Evaluation of hemodynamic effects of nitroglycerin on the utility of transesophageal echocardiography for diagnosis of coronary artery stenosis

We evaluated left anterior descending coronary artery stenosis by transesophageal echocardiography using the acute hemodynamic effects produced by administration of nitroglycerin (NTG) spray in 11 patients with stenosis and 8 subjects without stenosis (normal group). Before administration of NTG, there were no differences in systolic and diastolic blood pressure, heart rate, the diameter of the left main trunk, systolic flow velocity (SFV), diastolic flow velocity (DFV), or the ratio of diastolic flow velocity to systolic flow velocity (DFV:SFV) between the normal and stenosis groups. NTG administration significantly reduced systolic and diastolic blood pressures and significantly increased heart rate and the diameter of the left main trunk in each group. The increase in diameter of the left main trunk was significantly greater in the normal group compared with the stenosis group, despite the lack of significant differences in NTG-induced changes in blood pressure and heart rate between the two groups. NTG significantly increased peak SFV and DFV in both groups. The average NTG-induced change in SFV was similar in both groups, but the increase in DFV was significantly greater in the stenosis group compared with the normal group. Consequently, the DFV:SFV decreased significantly after NTG administration in the normal group but not in the stenosis group. The change in DFV:SFV was significantly different between the two groups. Our results suggest that NTG spray is potentially useful for enhancing the diagnostic utility of transesophageal echocardiography for stenosis of the left descending coronary artery.

A neuro-fuzzy algorithm for diagnosis of coronary artery stenosis

In this paper a method of fuzzy decision making applied to diagnosis of coronary artery stenosis is presented. The method uses a neural network approach for the diagnosis of stenosis in the three main coronary arteries (left anterior descending, right coronary artery, and circumflex). First, the knowledge base domain, 201Tl scintigram training data, is explained and the method of preprocessing the original heart images is given. Next, the method of dealing with the uncertainties present in the data using the fuzzy approach is outlined. Finally, the algorithm and the results are discussed and compared with other approaches.

An expert system for diagnosis of coronary artery stenosis based on 201TI scintigrams using the Dempster-Shafer theory of evidence

An expert system for the diagnosis of stenoses in the three main coronary arteries (left anterior descending, right coronary artery and circumflex) is described. First, the knowledge base domain--201Tl scintigrams--is explained and the method of preprocessing the original heart images is given. Next, the method of dealing with the uncertainties present both in the cardiologist-specified rules and the data using the Dempster-Shafer theory of evidence is explained. Finally, the constructed expert system and the results are discussed and several graphical examples are shown.