中危人群双源CT冠脉显像检测冠状动脉狭窄的可靠性

目的探讨冠状动脉(冠脉)双源CT(DSCT)评价冠状动脉性心脏病(冠心病)中危人群冠脉狭窄的准确性。方法选择2006-07-2009-05至我院行冠状动脉造影(冠脉造影)的冠心病中危患者67例,男42例,女25例,分别给予双源CT和冠脉造影检查(不予心率控制)。双盲法对图像资料结果进行比较分析。结果66例获得了清晰的图像。在至少有一处狭窄>50%的患者16例中,15例由双源CT准确发现,敏感性93.8%。在无狭窄>50%的患者50例中,45例由双源CT准确排除,特异性90.0%。双源CT诊断冠脉狭窄≥50%的敏感性为94.3%,特异性98.8%,阳性预测值75.0%,阴性预测值99.8%;诊断冠脉狭窄≥75%的敏感性为94.1%,特异性99.4%,阳性预测值76.2%,阴性预测值99.9%。kappa一致性分析发现双源CT与冠脉造影的结果有较好的一致性(κ=0.79,P<0.01)。结论双源CT判断冠心病中危人群冠脉狭窄情况的敏感性及特异性均较高,可作为此人群筛查的安全、可靠方法。     

64-slice computed tomography coronary angiography in patients with high, intermediate, or low pretest probability of significant coronary artery disease.

OBJECTIVES: We assessed the usefulness of 64-slice computed tomography coronary angiography (CTCA) to detect or rule out coronary artery disease (CAD) in patients with various estimated pretest probabilities of CAD. BACKGROUND: The pretest probability of the presence of CAD may impact the diagnostic performance of CTCA. METHODS: Sixty-four-slice CTCA (Sensation 64, Siemens, Forchheim, Germany) was performed in 254 symptomatic patients. Patients with heart rates > or =65 beats/min received beta-blockers before CTCA. The pretest probability for significant CAD was estimated by type of chest discomfort, age, gender, and traditional risk factors and defined as high (> or =71%), intermediate (31% to 70%), and low (< or =30%). Significant CAD was defined as the presence of at least 1 > or =50% coronary stenosis on quantitative coronary angiography, which was the standard of reference. No coronary segments were excluded from analysis. RESULTS: The estimated pretest probability of CAD in the high (n = 105), intermediate (n = 83), and low (n = 66) groups was 87%, 53%, and 13%, respectively. The diagnostic performance of the computed tomography (CT) scan was different in the 3 subgroups. The estimated post-test probability of the presence of significant CAD after a negative CT scan was 17%, 0%, and 0% and after a positive CT scan was 96%, 88%, and 68%, respectively. CONCLUSIONS: Computed tomography coronary angiography is useful in symptomatic patients with a low or intermediate estimated pretest probability of having significant CAD, and a negative CT scan reliably rules out the presence of significant CAD. Computed tomography coronary angiography does not provide additional relevant diagnostic information in symptomatic patients with a high estimated pretest probability of CAD.     

Usefulness of noninvasive cardiac imaging using dual-source computed tomography in an unselected population with high prevalence of coronary artery disease

The aim of the present study was to evaluate the diagnostic accuracy of a new dual-source computed tomographic scanner generation with 83-ms temporal resolution in cardiac imaging. Fifty-one unselected consecutive patients (mean age 64 +/- 10 years) scheduled for invasive coronary angiography because of suspected or known coronary artery disease (CAD) were examined with dual-source computed tomography (DSCT). All coronary segments were analyzed regarding the presence of coronary artery lesions. The findings were compared with invasive coronary angiography. During computed tomographic examination, mean heart rate was 65 +/- 14 beats/min. Thirteen of 51 patients (25%) did not have sinus rhythm. Mean Agatston score equivalent was 779 (median 358, range 0 to 3,898). Prevalence of CAD was 75%. Based on a coronary segment model, sensitivity was 96%, specificity 87%, positive predictive value 61%, and negative predictive value 99% for the detection of significant lesions (> or =50% diameter stenosis). The main reason for false-positive results was an overestimation of mild lesions by DSCT. In conclusion, our initial data indicate that DSCT allows a high accuracy to exclude relevant coronary stenosis in unselected patients with a high prevalence of CAD and a relevant number with heart rhythm irregularities. However, overestimation of stenosis, especially in cases of calcifications, is still a limitation.     

Impact of clinical presentation and pretest likelihood on the relation between calcium score and computed tomographic coronary angiography

The purpose of the present study was to assess the impact of clinical presentation and pretest likelihood on the relation between coronary calcium score (CCS) and computed tomographic coronary angiography (CTA) to determine the role of CCS as a gatekeeper to CTA in patients presenting with chest pain. In 576 patients with suspected coronary artery disease (CAD), CCS and CTA were performed. CCS was categorized as 0, 1 to 400, and >400. On CT angiogram the presence of significant CAD (≥50% luminal narrowing) was determined. Significant CAD was observed in 14 of 242 patients (5.8%) with CCS 0, in 94 of 260 patients (36.2%) with CCS 1 to 400, and in 60 of 74 patients (81.1%) with CCS >400. In patients with CCS 0, prevalence of significant CAD increased from 3.9% to 4.1% and 14.3% in nonanginal, atypical, and typical chest pain, respectively, and from 3.4% to 3.9% and 27.3% with a low, intermediate, and high pretest likelihood, respectively. In patients with CCS 1 to 400, prevalence of significant CAD increased from 27.4% to 34.7% and 51.7% in nonanginal, atypical, and typical chest pain, respectively, and from 15.4% to 35.6% and 50% in low, intermediate, and high pretest likelihood, respectively. In patients with CCS >400, prevalence of significant CAD on CT angiogram remained high (>72%) regardless of clinical presentation and pretest likelihood. In conclusion, the relation between CCS and CTA is influenced by clinical presentation and pretest likelihood. These factors should be taken into account when using CCS as a gatekeeper for CTA.     

Flash双源CT冠脉成像与心肌灌注显像对冠心病诊断价值的临床研究

目的探讨Flash双源CT冠状动脉成像（DS—CTA）与心肌灌注显像（DS—CTP）一站式检查对冠心病诊断的价值。方法对60例临床考虑冠心病的患者行双源CT检查,所有患者均接受冠状动脉造影检查。以冠状动脉造影为参考标准,根据冠脉造影结果分为狭窄〈50％和狭窄≥50％,计算对于狭窄≥50％者双源CT冠脉成像及联合心肌灌注显像对冠心病诊断的敏感性、特异性、阳性预测值、阴性预测值和准确性。结果60例患者行DSCT冠脉成像与心肌灌注显像,其中59例均显示良好符合诊断要求。以冠状动脉造影为参考标准：①对于血管狭窄≥50％的血管,Flash双源CT诊断敏感性、特异性、阳性预测值和阴性预测值分别为84．O％、92．7％、88．9％和89．1％;②DS—CTA联合DS—CTP诊断冠心病的敏感性、特异性、阳性预测值和阴性预测值分别为96．8％、90．7％％、88．5％和97．5％。结论DS—CTA联合DS—CTP对冠心病具有很高的诊断价值。双源CT这种融合解剖学及功能学成像的“一站式”检查方法在冠心病的诊断及预后方面有重要优势。     

Comparison of the Diamond-Forrester method and Duke Clinical Score to predict obstructive coronary artery disease by computed tomographic angiography

We sought to evaluate the ability of the Diamond and Forrester method (DFM) and the Duke Clinical Score (DCS) to predict obstructive coronary artery disease (CAD) on coronary computed tomographic angiography (CCTA) and the effect of these different risk scores on the appropriateness level using the 2010 Appropriate Use Criteria. Consecutive symptomatic patients who underwent CCTA for evaluation of CAD (n = 114) were classified as having a low, intermediate, or high pretest probability using the DFM and DCS. Using the Appropriate Use Criteria, the indications for CCTA were classified according to the pretest probability and previous testing. The CCTA results were classified as revealing obstructive (≥70% stenosis), nonobstructive (<70%), or no CAD. When the patients' risk was classified using the DFM, 18% were low, 65% intermediate, and 17% high risk. When using the DCS, 53% of patients had a reclassification of their risk, most of whom changed from intermediate to either low or high risk (50% low, 19% intermediate, 35% high risk). The net reclassification improvement for the prediction of obstructive CAD was 51% (p = 0.01). Of the 37 patients who were reclassified as low risk, 36 (97%) lacked obstructive CAD. Appropriateness for CCTA was reclassified for 13% of patients when using the DCS instead of the DFM, and the number of appropriate examinations was significantly fewer (68% vs 55%, p <0.001). In conclusion, reclassification of risk using the DCS instead of the DFM resulted in improved prediction of obstructive CAD on CCTA, especially in low-risk patients. More patients were categorized as having a high pretest probability of CAD, resulting in reclassification of their examination indications as uncertain or inappropriate. These results identify the need for improved pretest risk scores for noninvasive tests such as CCTA and suggest that the method of risk assessment could have important implications for patient selection and quality assurance programs.     

Relationship between noninvasive coronary angiography with multi-slice computed tomography and myocardial perfusion imaging.

OBJECTIVES: The aim of this study was to perform a head-to-head comparison between multi-slice computed tomography (MSCT) and myocardial perfusion imaging (MPI) in patients with an intermediate likelihood of coronary artery disease (CAD) and to compare non-invasive findings to invasive coronary angiography. BACKGROUND: Multi-slice computed tomography detects atherosclerosis, whereas MPI detects ischemia; how these 2 techniques compare in patients with an intermediate likelihood of CAD is unknown. METHODS: A total of 114 patients, mainly with intermediate likelihood of CAD, underwent both MSCT and MPI. The MSCT studies were classified as having no CAD, nonobstructive (<50% luminal narrowing) CAD, or obstructive CAD. Myocardial perfusion imaging examinations were classified as showing normal or abnormal (reversible and/or fixed defects). In a subset of 58 patients, invasive coronary angiography was performed. RESULTS: On the basis of the MSCT data, 41 patients (36%) were classified as having no CAD, of whom 90% had normal MPI. A total of 33 patients (29%) showed non-obstructive CAD, whereas at least 1 significant (> or =50% luminal narrowing) lesion was observed in the remaining 40 patients (35%). Only 45% of patients with an abnormal MSCT had abnormal MPI; even in patients with obstructive CAD on MSCT, 50% still had a normal MPI. In the subset of patients undergoing invasive angiography, the agreement with MSCT was excellent (90%). CONCLUSIONS: Myocardial perfusion imaging and MSCT provide different and complementary information on CAD, namely, detection of atherosclerosis versus detection of ischemia. As compared to invasive angiography, MSCT has a high accuracy for detecting CAD in patients with an intermediate likelihood of CAD.     

Fragmented QRS complex is an independent predictor of plaque burden in patients at intermediate risk of coronary artery disease

ObjectiveWe aimed to evaluate the relationship between fragmented QRS complex and plaque burden in patients presented with typical chest pain and deemed to have intermediate pretest probability of CAD using coronary computed tomography angiography (CCTA).MethodsWe studied electrocardiograms (ECGs) obtained from 172 subjects (47.5 ± 9.5 years, 125 were men) presented with chest pain and had intermediate pretest probability for CAD. The presence was found and evaluation of CAD was performed with CCTA.ResultsSeventy four (43%) of the study cohort had CCTA-documented CAD. Meanwhile the frequency of fQRS in our cohort was (57%). 70 (71.4%) patients with fQRS had CAD compared with only 4 (5.4%) patients without fQRS (p < 0.001). The number of leads with fQRs was correlated with the calcium score (p < 0.005), segment stenosis score, segment involvement score, total plaque score (TPS), and E/e ratio (p < 0.001, for all). Multivariate analysis demonstrated that fQRS was a strong independent predictor for CAD (or = 2.15, p < 0.001). ROC analysis showed that the number of leads ≥3 was the optimal number for predicting CAD (AUC = 0.89, sensitivity 88%, and specificity 83%, p < 0.001).ConclusionFragmented QRS was seen more often in patients with high plaque burden. We suggest that fQRS might provide a useful noninvasive prognosticator for subjects with intermediate pretest probability of CAD for further investigation.     

Comparison of diagnostic accuracy of 64-slice computed tomography coronary angiography in women versus men with angina pectoris

We compared the diagnostic accuracy of 64-slice computed tomographic (CT) coronary angiography to detect significant coronary artery disease (CAD) in women and men. The 64-slice CT coronary angiography was performed in 402 symptomatic patients, 123 women and 279 men, with CAD prevalence of 51% and 68%, respectively. Significant CAD, defined as > or =50% coronary stenosis on quantitative coronary angiography, was evaluated on a patient, vessel, and segment level. The sensitivity and negative predictive value to detect significant CAD was very good, both for women and men (100% vs 99%, p = NS; 100% vs 98%, p = NS), whereas diagnostic accuracy (88% vs 96%; p <0.01), specificity (75% vs 90%, p <0.05), and positive predictive value (81% vs 95%, p <0.001) were lower in women. The per-segment analysis demonstrated lower sensitivity in women compared with men (82% vs 93%, p <0.001). The sensitivity in women did not show a difference in proximal and midsegments, but was significantly lower in distal segments (56% vs 85%, p <0.05) and side branches (54% vs 89%, p <0.001). In conclusion, CT coronary angiography reliably rules out the presence of obstructive CAD in both men and women. Specificity and positive predictive value of CT coronary angiography were lower in women. The sensitivity to detect stenosis in small coronary branches was lower in women compared with men.     

Adenosine technetium-99m sestamibi myocardial perfusion SPECT in women: Diagnostic efficacy in detection of coronary artery disease

Objectives. This study sought to assess the diagnostic efficacy of adenosine technetium-99m (Tc-99m) sestamibi myocardial perfusion single-photon emission computed tomography (SPECT) in a consecutive series of female patients.Background. The utility of adenosine myocardial perfusion SPECT for the detection of coronary artery disease is not well defined in women because most studies have described a predominantly male population with a high prevalence of coronary artery disease.Methods. Of the 201 consecutive female patients in the study group who had undergone adenosine Tc-99m sestamibi myocardial perfusion SPECT, 130 had coronary angiography within 2 months of the nuclear test, and the other 71 had a low likelihood (<10%, mean [±SD] 5 ± 3%) of coronary artery disease. The SPECT protocol used separate acquisition of rest thallium-201 and adenosine Tc-99m sestamibi and was visually analyzed in 20 segments with a semiquantitative five-point scoring system (0 = normal; 4 = absent uptake).Results. The normaley rate in patients with a low likelihood of coronary artery disease was 93% (66 of 71). Among the catheterized group, the overall sensitivity, specificity and predictive accuracy of adenosine sestamibi SPECT for detecting coronary artery disease (⪰50% diameter stenosis) were 93% (87 of 94), 78% (28 of 36) and 88% (115 of 130), respectively. In the 103 patients without a prior myocardial infarction, the sensitivity, specificity and predictive accuracy were 91% (61 of 67), 78% (28 of 36) and 86% (89 of 103), respectively, for detecting ⪰50% diameter stenosis. Of particular interest, the sensitivity and specificity were as high in patients with nonanginal symptoms (93% and 69%, respectively) as in patients with angina (92% and 83%, respectively, p = NS). The sensitivity and specificity among patients with a relatively low (<25%), intermediate (between 25% and 75%) or high prescan likelihood of coronary artery disease (>75%) were similar: 82% and 82%, 93% and 73%, and 95% and 100%, respectively. The sensitivity and specificity for detecting individual diseased vessels (⪰50% diameter stenosis) were, respectively, 76% and 81% for the left anterior descending coronary artery, 44% and 90% for the left circumflex coronary artery and 75% and 77% for the right coronary artery.Conclusions. Adenosine Tc-99m sestamibi SPECT is an efficient protocol with high sensitivity and specificity for the detection of coronary artery disease in women irrespective of presenting symptoms or pretest likelihood of coronary artery disease and a high normaley rate. These findings are of particular clinical relevance because chest pain, anginal or otherwise, has been shown to be a frequent but a less specific marker for coronary artery disease among female patients.     

Prognostic value of multidetector coronary computed tomographic angiography for prediction of all-cause mortality.

OBJECTIVES: The purpose of this study was to examine the association of all-cause death with the coronary computed tomographic angiography (CCTA)-defined extent and severity of coronary artery disease (CAD). BACKGROUND: The prognostic value of identifying CAD by CCTA remains undefined. METHODS: We examined a single-center consecutive cohort of 1,127 patients > or =45 years old with chest symptoms. Stenosis by CCTA was scored as minimal (<30%), mild (30% to 49%), moderate (50% to 69%), or severe (> or =70%) for each coronary artery. Plaque was assessed in 3 ways: 1) moderate or obstructive plaque; 2) CCTA score modified from Duke coronary artery score; and 3) simple clinical scores grading plaque extent and distribution. A 15.3 +/- 3.9-month follow-up of all-cause death was assessed using Cox proportional hazards models adjusted for pretest CAD likelihood and risk factors. Deaths were verified by the Social Security Death Index. RESULTS: The CCTA predictors of death included proximal left anterior descending artery stenosis and number of vessels with > or =50% and > or =70% stenosis (all p < 0.0001). A modified Duke CAD index, an angiographic score integrating proximal CAD, plaque extent, and left main (LM) disease, improved risk stratification (p < 0.0001). Patients with <50% stenosis had the highest survival at 99.7%. Survival worsened with higher-risk Duke scores, ranging from 96% survival for 1 stenosis > or =70% or 2 stenoses > or =50% (p = 0.013) to 85% survival for > or =50% LM artery stenosis (p < 0.0001). Clinical scores measuring plaque burden and distribution predicted 5% to 6% higher absolute death rate (6.6% vs. 1.6% and 8.4% vs. 2.5%; p = 0.05 for both). CONCLUSIONS: In patients with chest pain, CCTA identifies increased risk for all-cause death. Importantly, a negative CCTA portends an extremely low risk for death.     

Influence of coronary computed tomographic angiography on patient treatment and prognosis in patients with suspected stable angina pectoris

We evaluated the influence of coronary computed tomographic angiography (CTA) as a first-line diagnostic test on patient treatment and prognosis. A total of 1,055 consecutive patients with suspected stable angina pectoris (mean age 55 ± 10 years, 56% women) and a low to intermediate pretest likelihood of coronary artery disease (CAD) were included in the present study. The patients were followed for a median of 18 months. The use of downstream diagnostic testing and medical therapy after CTA were recorded. The CTA result was normal in 49%, and nonobstructive and obstructive CAD (≥50% stenosis) was demonstrated in 31% and 15% of the patients, respectively. Coronary CTA was inconclusive in 5% of the patients. The use of antiplatelet therapy decreased with normal findings from CTA, and the use of antiplatelet and lipid-lowering agents increased in patients with CAD. Additional testing was performed in 2% of patients with normal CTA findings and in 7% and 82% of patients with nonobstructive or obstructive CAD, respectively. No patients without CAD, 0.9% of patients with nonobstructive CAD, and 1.9% of patients with obstructive CAD met the primary end point (cardiovascular death and myocardial infarction, p = 0.008). No patients without CAD, 1.5% of patients with nonobstructive CAD, and 30% patients with obstructive CAD met the secondary end point (cardiovascular death, myocardial infarction, and coronary revascularization, p <0.0001). In conclusion, in patients suspected of having angina, the findings from CTA influence patient treatment without resulting in excessive additional testing. Coronary CTA provides important prognostic information, with excellent intermediate-term outcomes in patients with normal CTA findings.     

The Diagnostic Value of ST Segment Analysis in Ambulatory ECG Monitoring Evaluated Using Bayes' Theorem in Patients Screened for Coronary Artery Disease

Background: The diagnostic value of ambulatory ECG monitoring in screening for coronary artery disease has been studied in diverse and usually small groups of patients. There are no studies evaluating the diagnostic value of Holter recorded ST depression using the Bayes' theorem of probability, which accounts for the prevalence of the disease in prespecified populations. Purpose: Applying the Bayes' theorem, this study aimed to examine the diagnostic value of Holterrecorded 1-mm ST depression in patients screened for coronary artery disease (CAD) and to identify groups of patients who may benefit from diagnostic ST segment monitoring in ambulatory ECG recordings. Methods: The ST segment analysis was performed in 24-hour ambulatory ECG monitoring of 460 subjects (375 males; aged 35–65, mean 48.6 years), who were screened for CAD and had coronary angiography. The Bayes' formulae were used to calculate the predictive value of ST segment monitoring (posttest likelihood of CAD) in comparison to pretest likelihood of the disease based on age, gender, and symptoms. Results: The 1-mm ST depression was identified in the ambulatory ECG monitoring in 203 (44%) patients. CAD was angiographically confirmed in 279 (61%) patients. The 1-mm ST depression had 54% sensitivity, 71% specificity, 74% positive predictive value, and 50% negative predictive value for CAD. The Bayes' theorem analysis with adjustment for pretest likelihood of the disease in relation to age, gender, and symptoms showed that 1-mm ST segment depression is significant diagnostically in patients with pretest likelihood of the disease exceeding 75%, i.e., in males aged 35–45 years and females aged 56–65 years, both with typical angina. In other groups of patients regardless of the symptoms, age, and gender, detection of ST segment depression does not improve the diagnostic process. A negative result (absence of ST segment depression) can be helpful, confirming the absence of CAD in patients with 15%–25% pretest likelihood of the disease, i.e., in females aged 35–45 years with atypical angina pains and in males aged 46–55 years with nonanginal chest pains. Conclusions: Based on our observations, the 1-mm ST segment depression detected on 24-hour ambulatory ECG monitoring indicates a high likelihood of CAD in patients with < 75% pretest likelihood of the disease. ST segment analysis in other age and gender relative groups of patients, regardless of the nature of their symptoms, does not significantly improve diagnosis process.     

Comparative ability of myocardial perfusion single-photon emission computed tomography to detect coronary artery disease in patients with and without diabetes mellitus

BACKGROUND: Diabetics generally have more frequent and extensive silent myocardial ischemia than nondiabetics, increasing the importance of noninvasive detection of coronary artery disease (CAD) in this cohort. However, little is known regarding the diagnostic accuracy of myocardial perfusion single-photon emission computed tomography (SPECT) in patients with diabetes. This study was undertaken to compare the diagnostic value of rest thallium-201/stress technetium-99m sestamibi dual-isotope myocardial perfusion SPECT in patients with and without diabetes. METHODS: Of the 203 patients with diabetes and 260 patients without diabetes who underwent dual-isotope myocardial perfusion SPECT with exercise or pharmacologic stress testing, 138 diabetics (12% type 1 diabetics) and 188 nondiabetics had coronary angiography within 6 months of the nuclear test, and 65 diabetics and 72 nondiabetics had a low likelihood (<10%, mean 6% +/- 3% and 6% +/- 3%) of CAD. RESULTS: The angiographic data showed that patients with diabetes had less incidence of 1-vessel disease and a higher incidence of 3-vessel/left main artery disease than patients without diabetes (P <.05). The overall sensitivity and specificity, respectively, of SPECT for detecting CAD with the criterion of >/=50% diameter stenosis were 86% (95 of 111) and 56% (15 of 27) in diabetics, 86% (122 of 142) and 46% (21 of 46) in nondiabetics (P = not significant). With the criterion of >/=70% diameter stenosis the corresponding results were 90% (86 of 96) and 50% (21 of 42) in diabetics, and 91% (108 of 119) and 43% (30 of 69) in nondiabetics, respectively (P = not significant). The normalcy rate for low likelihood patients was 89% (58 of 65) in diabetics and 90% (65 of 72) in nondiabetics (P = not significant). The sensitivity and specificity for individual vessel detection were also similar in patients with and without diabetes (P = not significant) except for a lower sensitivity and a higher specificity for detecting left anterior descending coronary artery disease in the diabetic group (P <.05). CONCLUSION: Dual-isotope myocardial perfusion SPECT has comparable accuracy for the diagnosis of CAD in diabetic and nondiabetic patients.     

Angina pectoris in severe aortic stenosis

We studied the value of angina pectoris as a predictor of significant coronary artery disease (CAD) in very elderly patients with severe aortic stenosis (AS). The study population consisted of patients with age at least 70 years who were referred for balloon aortic valvuloplasty (n = 90 patients). Routine coronary angiography was performed before the valvular intervention. Patients were grouped according to the presence or absence of angina pectoris. Of the patients with angina pectoris, 78% had obstructive (>50% diameter stenosis) CAD on coronary angiogram, while only 17% of patients without angina pectoris had obstructive CAD (p < 0.01). Angina pectoris had a sensitivity of 78% and a specificity of 82% for prediction of obstructive CAD. This suggests that in elderly patients with severe AS, the presence of angina pectoris is a strong determinant of CAD, and the absence of angina strongly suggests absence of obstructive CAD. In a very elderly population, appropriate decision-making with respect to AS management should not await diagnostic coronary angiography.     

Bayesian analysis using fourier transforms of thallium-201 scintiscans to predict the presence of coronary artery disease

Bayes' theorem of conditional probability was applied to the diagnosis of coronary artery disease (CAD) using thallium-201 scintigraphy as the testing procedure. Thallium-201 scintiscans were evaluated with a discriminant function previously developed using the amplitude coefficients of the Fourier transforms of the scams. The technique was applied prospectively to a population of 100 patients undergoing diagnostic coronary arteriography and thallium-201 scintigraphy, including 83 patients with CAD (70% or greater stenosis of luminal diameter) and 17 control subjects. A pretest probability of CAD was determined for each patient from the patient's age, sex and anginal symptoms. The pretest probability was combined with the patient's discriminant score to determine a posttest probability for CAD. For patients with CAD, the mean posttest probability was 0.85. Moreover, 57 of 83 patients (69%) had posttest probabilities exceeding 90%, including 40 patients (48%) with posttest probabilities exceeding 99%. For control subjects, the mean posttest probability was 0.19, with 11 of 17 (65%) having a posttest probability of less than 10%. Overall, 68 subjects had a posttest probability either less than 10% or more than 90% of which 63 were correctly classified (93%). Using a 50% posttest probability as a cutoff for classification, the technique has an 89% sensitivity, an 82% specificity and an overall accuracy of 88%. Therefore, this method objectively distinguishes patients with CAD from control subjects and provides a measure of the certainty of diagnosis. In addition, the discriminant function avoids the problem of inter- and ihtraobserver variability in visually interpreting thallium-201 scans.     

Stress echocardiography is superior to exercise ECG in the risk stratification of patients presenting with acute chest pain with negative Troponin.

OBJECTIVE: To compare exercise electrocardiography (ExECG) and stress echocardiography (SE) in the risk stratification of patients presenting to hospital with cardiac-sounding chest pain, non-diagnostic ECGs and negative cardiac Troponin. METHODS: Patients presenting with acute chest pain were prospectively randomised to early ExECG or SE. A post-test likelihood of CAD was determined by the pre-test likelihood and the result of the stress test. Patients with a low post-test likelihood of CAD were discharged; those with a high post-test probability were considered for coronary angiography. All others were managed according to standard hospital protocols. RESULTS: A total of 302 patients underwent either ExECG or SE. SE identified significantly more patients with a low post-test probability of CAD (80% vs 31%, p<0.0001) and significantly fewer patients with an intermediate post-test likelihood of CAD compared to ExECG (3% vs 47%; p<0.0001). Significantly fewer patients undergoing SE were referred for further tests to exclude or refute the diagnosis of CAD (16% vs 52%; p<0.0001). In total, 36 (12%) had flow limiting CAD demonstrated by coronary angiography. Significant CAD was seen in fewer patients with a positive ExECG than with a positive SE (56% vs 84% (p=0.12)). Event rates were low for both modalities in patients with low post-test probability (3.5% for SE vs 5.1% for ExECG; p=ns) though the number of patients identified as low risk was higher if SE was performed. CONCLUSION: Despite negative cardiac Troponin, 12% of patients with acute chest pain had significant CAD. SE is superior to ExECG in discriminating between those patients with a low and intermediate risk of CAD and correctly identified patients with significant CAD, as well as conferring an excellent prognosis in those considered low risk. SE significantly reduces the requirement for further tests to diagnose CAD compared to ExECG.     

Angiographic coronary artery disease is associated with progressively higher levels of fasting plasma glucose

This study evaluated the association between progressively higher levels of fasting glycemia (G) and insulin resistance parameters with coronary artery disease (CAD) in patients referred for coronary angiography. All 145 patients (age 58.4+/-0.9 years, 51.7% men) underwent clinical and laboratory evaluation before coronary angiography and subjects were divided into four groups: normal (N, <88 mg/dl), high-normal (H-N, 89-99 mg/dl), impaired fasting glucose (IFG, 100-125 mg/dl) and diabetes (DM, >126 mg/dl or known diabetics). Arteriographic evidence of CAD was determined by two criteria: (1) a 30% or greater diameter stenosis in at least one major coronary artery; (2) a 70% or greater diameter stenosis in at least one major coronary artery. HOMA-IR increased progressively according to each group: N=1.74+/-0.2, H-N=3.14+/-0.3, IFG=4.67+/-0.6 and DM=8.00+/-2.9; p=0.001. The proportion of patients with CAD according to both criteria increased with each G level: CAD criteria 1: N=39.4%, H-N=50%, IFG=60% and DM=69.6%, p=0.006; CAD criteria 2: N=27.3%, H-N=30%, IFG=36% and DM=50%, p=0.03. We demonstrated a significant association between subtle disturbances of the glucose metabolism, assessed by subnormal levels of fasting glucose and insulin resistance parameters, and angiographically documented coronary artery disease.     

老年冠状动脉疾病双源CT检查的临床意义

目的探讨双源CT（DSCT）在老年冠状动脉疾病检查中的临床意义。方法对58例有症状拟诊冠心病心绞痛或有冠心病高危因素的老年患者应用DSCT检查。对12例中重度患者行选择性冠状动脉造影（SCA）检查。以SCA检查结果为金标准,探讨2种检查方法在诊断老年冠状动脉疾病方面有无统计学差异。结果 58例老年患者DSCT检查显示冠状动脉583段,狭窄病变126段,其中轻度狭窄病变45段,中度狭窄病变39段,重度狭窄病变39段,闭塞3段。DSCT和SCA在检查冠状动脉中重度狭窄及闭塞上无统计学差异（P〉0.05）。结论 DSCT是一种无创、简便、安全可靠的影像学的检查方法,有较高的敏感性和特异性,在评价老年患者中重度冠脉狭窄上与SCA具有较高的符合性与一致性,值得临床推广。     

Prevalence of multivessel coronary artery disease in patients with diabetes mellitus plus hypothyroidism, in patients with diabetes mellitus without hypothyroidism, and in patients with no diabetes mellitus or hypothyroidism

BACKGROUND: We report the prevalence of significant multivessel coronary artery disease (CAD) (>50% stenosis) in patients with diabetes plus hypothyroidism, in patients with diabetes without hypothyroidism, and in patients without diabetes or hypothyroidism who had significant CAD documented by coronary angiography. METHODS: We performed a retrospective analysis in 100 patients selected randomly with significant CAD documented by coronary angiography to investigate the prevalence of significant multivessel CAD in patients with diabetes, in patients with hypothyroidism, and in patients without diabetes or hypothyroidism. RESULTS: Significant 3-4-vessel CAD was present in 9 of 10 patients (90%), mean age 73 +/- 11 years, with diabetes plus hypothyroidism, in 10 of 25 patients (40%), mean age 63 +/- 9 years, with diabetes without hypothyroidism, and in 10 of 65 patients (15%), mean age 68 +/- 12 years, without diabetes or hypothyroidism (p <.001 comparing diabetes plus hypothyroidism with no diabetes or hypothyroidism; p <.01 comparing diabetes plus hypothyroidism with diabetes without hypothyroidism; and p <.02 comparing diabetes without hypothyroidism with no diabetes or hypothyroidism). Significant 2-4-vessel CAD was present in 10 of 10 patients (100%) with diabetes plus hypothyroidism, in 20 of 25 patients (80%) with diabetes without hypothyroidism, and in 37 of 65 patients (57%) with no diabetes or hypothyroidism (p <.01 comparing diabetes plus hypothyroidism with no diabetes or hypothyroidism; and p <.05 comparing diabetes without hypothyroidism with no diabetes or hypothyroidism). CONCLUSIONS: In patients with diabetes mellitus plus hypothyroidism, the prevalence of 3-vessel or 4-vessel CAD was significantly higher than in patients with diabetes mellitus without hypothyroidism or in patients with no diabetes mellitus or hypothyroidism. In patients with diabetes mellitus without hypothyroidism, the prevalence of 3-vessel or 4-vessel CAD was significantly higher than in patients without diabetes mellitus or hypothyroidism.