Electron beam CT and cost-efficient diagnosis of coronary artery disease

Summary Background: Electron beam CT (EBCT) can acquire rapid, multiple thin-section tomograms of the beating heart in synchrony with the electrocardiogram and quantify coronary calcification without intravenous contrast. Coronary calcification is an active process exclusively associated with atherosclerotic plaque formation and regulated in a manner similar to the calcification of bone. Clinical studies have demonstrated that EBCT coronary calcification (1) follows a pattern similar to the epidemiology of coronary artery disease (CAD), (2) has a high sensitivity (90–95 %) for coronary plaque and significant angiographic coronary stenoses, and (3) has the potential to assess the prognosis of patients with coronary atherosclerotic disease. Coronary calcium area or “score” correlates best with overall plaque burden within the coronary system. However, coronary calcium is of limited value in distinguishing coronary stenosis on a segment-by-segment basis. EBCT and CAD: Due to spiraling health care costs, there is a need for cost-efficient strategies in the diagnosis and stratification of patients with known or suspected CAD. There are two major patient groups in which EBCT calcium scanning has a potential for cost-efficient application: (1) in asymptomatic, high-risk patients, identification of significant plaque burden may direct judicious use of long-term drug therapy or further investigation to those individuals most likely to benefit from an aggressive risk factor modification and medical program; (2) in patients with chest pain syndromes but no prior CAD, EBCT calcium scanning compares favorably with conventional diagnostic methods. In particular, using receiver operating characteristic analysis, the sensitivity and specificity of an EBCT calcium score of 80 in detecting obstructive CAD are both about 85 %. Using a theoretical model, EBCT calcium scanning was found to be the most cost-effective approach to diagnosis in populations with a low-to-moderate likelihood of obstructive CAD when compared with treadmill exercise, stress thallium, and stress echocardiography. Conclusions: EBCT calcium scanning is not a substitute for coronary angiography, but it has clear advantages over other more traditional diagnostic methods for CAD. In particular, it can be performed conveniently and inexpensively in most patients. Additionally, the site and extent of calcification are intimately related to the atherosclerotic plaque burden. The analyses presented suggest that it may also provide a cost-effective clinical alternative in specific subsets of the population. Eingegangen am 15. Januar 1996 Angenommen am 27. Februar 1996     

Plaque volume,composition, and fraction versus ischemia and outcomes in patients with coronary artery disease

BackgroundThe various plaque components have been associated with ischemia and outcomes in patients with coronary artery disease (CAD). The main goal of this analysis was to test the hypothesis that, at patient level, the fraction of non-calcified plaque volume (PV) of total PV is associated with ischemia and outcomes in patients with CAD. This ratio could be a simple and clinically useful parameter, if predicting outcomes.MethodsConsecutive patients with suspected CAD undergoing coronary computed tomography angiography with selective positron emission tomography perfusion imaging were selected. Plaque components were quantitatively analyzed at patient level. The fraction of various plaque components were expressed as percentage of total PV and examined among patients with non-obstructive CAD, suspected stenosis with normal perfusion, and those with reduced myocardial perfusion. Clinical outcomes included all-cause mortality and myocardial infarction.ResultsIn total, 494 patients (age 63 ​± ​9 years, 55% male) were included. Total PV and all plaque components were significantly larger in patients with reduced myocardial perfusion compared to patients with normal perfusion and those with non-obstructive CAD. During follow-up 35 events occurred. Patients with any plaque component ​≥ ​median showed worse outcomes (log-rank p ​< ​0.001 for all). In addition, low-attenuation plaque ​≥ ​median was associated with worse outcomes independent of total PV (adjusted HR: 2.754, 95% CI: 1.022–7.0419, p ​= ​0.045). The fractions of the various plaque components were not associated with outcomes.ConclusionLarger total PV or any plaque component at patient level are associated with abnormal myocardial perfusion and adverse events. The various plaque components as fraction of total PV lack additional prognostic value.     

Prognostic value of 64-slice coronary angiography in diabetes mellitus patients with known or suspected coronary artery disease compared with a nondiabetic population

PURPOSE: This study aimed to determine the prognostic value of coronary angiography with multislice computed tomography (MSCT) in a population of diabetic subjects with known or suspected ischaemic heart disease compared with a nondiabetic control population. MATERIALS AND METHODS: Forty-nine patients with type 2 diabetes mellitus (DM) [group 1; mean age 67.7+/-8.8 years; 32 men; mean body mass index (BMI) 28+/-3.9] and 49 patients without DM (group 2, with similar demographic and clinical characteristics) were studied with MSCT coronary angiography to exclude the presence of ischaemic coronary artery disease (CAD). Each group comprised 26 patients (53%) with no history of ischaemic coronary disease and 23 patients (47%) with a history of myocardial infarction and/or myocardial revascularisation. Clinical follow-up was performed by analysing correlations between the rate of cumulative cardiac events (cardiac death, nonfatal myocardial infarction, unstable angina, and myocardial revascularisation), the severity of CAD identified on MSCT, and the presence of DM as a cardiovascular risk factor. RESULTS: At mean follow-up of 20 months, univariate analysis of survival showed significant differences between the two groups (group 1 vs. group 2, p=0.046). Moreover, the cumulative cardiac event rate correlated significantly with the presence of significant CAD (>50% stenosis) in both groups (group 1: p=0.003; group 2: p=0.0004). CONCLUSIONS: Event-free survival is significantly lower in the diabetic population compared with the normal control population (p=0.046) and is closely correlated with the presence of significant CAD. MSCT is an effective method for stratifying such risk and, together with high diagnostic accuracy, provides additional prognostic value.     

Assessment of coronary artery disease and calcified coronary plaque burden by computed tomography in patients with and without diabetes mellitus

Purpose

To compare the coronary atherosclerotic burden in patients with and without type-2 diabetes using CT Coronary Angiography (CTCA).

Methods and Materials

147 diabetic (mean age: 65?±?10?years; male: 89) and 979 nondiabetic patients (mean age: 61?±?13?years; male: 567) without a history of coronary artery disease (CAD) underwent CTCA. The per-patient number of diseased coronary segments was determined and each diseased segment was classified as showing obstructive lesion (luminal narrowing >50%) or not. Coronary calcium scoring (CCS) was assessed too.

Results

Diabetics showed a higher number of diseased segments (4.1?±?4.2 vs. 2.1?±?3.0; p??400 (p?p?p?p?=?0.003) and obstructive CAD (12.5% vs. 3.8%, p?=?0.01). Among patients with CCS????10 all diabetics with obstructive CAD had a zero CCS and one patient was asymptomatic.

Conclusions

Diabetes was associated with higher coronary plaque burden. The present study demonstrates that the absence of coronary calcification does not exclude obstructive CAD especially in diabetics.     

Prognostic value of Morise clinical score, calcium score and computed tomography coronary angiography in patients with suspected or known coronary artery disease

Purpose

Our aim was to determine the prognostic value of computed tomography coronary angiography (CTCA), coronary artery calcium scoring (CACS) and Morise clinical score in patients with known or suspected coronary artery disease (CAD).

Materials and methods

A total of 722 patients (480 men; 62.7±10.9 years) who were referred for further cardiac evaluation underwent CACS and contrast-enhanced CTCA to evaluate the presence and severity of CAD. Of these, 511 (71%) patients were without previous history of CAD. Patients were stratified according to the Morise clinical score (low, intermediate, high), to CACS (0?C10, 11?C100, 101?C400, 401?C1,000, >1,000) and to CTCA (absence of CAD, nonsignificant CAD, obstructive CAD). Patients were followed up for the occurrence of major events: cardiac death, nonfatal myocardial infarction, unstable angina and revascularisation.

Results

Significant CAD (>50% luminal narrowing) was detected in 260 (36%) patients; nonsignificant CAD (<50% luminal narrowing) in 250 (35%) and absence of CAD in 212 (29%). During a mean follow-up of 20±4 months, 116 events (21 hard) occurred. In patients with normal coronary arteries on CTCA, the major event rate was 0% vs. 1.7% in patients with nonsignificant CAD and 7.3% in patients with significant CAD (p<0.0001). Three hard events (14%) occurred in patients with CACS??100 and two (9.5%) in patients with intermediate Morise score; one revascularisation was observed in a patient with low Morise score. At multivariate analysis, diabetes, obstructive CAD and CACS >1,000 were significant predictors of events (p<0.05).

Conclusions

An excellent prognosis was noted in patients with a normal CTCA (0% event rate). CACS ??100 and low-intermediate Morise score did not exclude the possibility of events at follow-up.     

Added value of coronary artery calcium score as an adjunct to gated SPECT for the evaluation of coronary artery disease in an intermediate-risk population.

The coronary artery calcium (CAC) score is a readily and widely available tool for the noninvasive diagnosis of atherosclerotic coronary artery disease (CAD). The aim of this study was to investigate the added value of the CAC score as an adjunct to gated SPECT for the assessment of CAD in an intermediate-risk population. METHODS: Seventy-seven prospectively recruited patients with intermediate risk (as determined by the Framingham Heart Study 10-y CAD risk score) and referred for coronary angiography because of suspected CAD underwent stress (99m)Tc-tetrofosmin SPECT myocardial perfusion imaging (MPI) and CT CAC scoring within 2 wk before coronary angiography. The sensitivity and specificity of SPECT alone and of the combination of the 2 methods (SPECT plus CAC score) in demonstrating significant CAD (>/=50% stenosis on coronary angiography) were compared. RESULTS: Forty-two (55%) of the 77 patients had CAD on coronary angiography, and 35 (45%) had abnormal SPECT results. The CAC score was significantly higher in subjects with perfusion abnormalities than in those who had normal SPECT results (889 +/- 836 [mean +/- SD] vs. 286 +/- 335; P < 0.0001). Similarly, with rising CAC scores, a larger percentage of patients had CAD. Receiver-operating-characteristic analysis showed that a CAC score of greater than or equal to 709 was the optimal cutoff for detecting CAD missed by SPECT. SPECT alone had a sensitivity and a specificity for the detection of significant CAD of 76% and 91%, respectively. Combining SPECT with the CAC score (at a cutoff of 709) improved the sensitivity of SPECT (from 76% to 86%) for the detection of CAD, in association with a nonsignificant decrease in specificity (from 91% to 86%). CONCLUSION: The CAC score may offer incremental diagnostic information over SPECT data for identifying patients with significant CAD and negative MPI results.     

Prognostic value of computed tomography coronary angiography in patients with suspected coronary artery disease: a 24-month follow-up study

The aim of this study was to determine the predictive value of 64-slice computed tomography coronary angiography (CTCA) for major cardiac events in patients with suspected coronary artery disease (CAD). A total of 187 consecutive patients (119 men, age 62.5 ± 10.5 years) without known heart disease underwent single-source 64-slice CTCA (Somatom Sensation 64, Siemens) for clinical suspicion of CAD. Patients underwent follow-up for the occurrence of cardiac death, nonfatal myocardial infarction, unstable angina and cardiac revascularization. In total, 2,822 coronary segments were assessed. Forty-two segments (1.5%) were not assessable because of insufficient image quality. Overall, CTCA revealed absence of CAD in 65 (34.7%) patients, nonobstructive CAD (coronary plaque ≤50%) in 87 (46.5%) patients and obstructive CAD (>50%) in 35 (18.8%) patients. A total of 20 major cardiac events (3 myocardial infarctions, 16 cardiac revascularizations, 1 unstable angina) occurred during a mean follow-up of 24 months. One noncardiac death occurred. Seventeen events occurred in the group of patients with obstructive CAD and three events occurred in the group of nonobstructive CAD. The event rate was 0% among patients with normal coronary arteries at CTCA. CTCA has a 100% negative predictive value for major cardiac events at 24-month follow-up in patients with normal coronary arteries.     

Diagnostic accuracy of dual-source computed tomography in the diagnosis of coronary artery disease

PURPOSE: The aim of this study was to evaluate the diagnostic accuracy of dual-source computed tomography (DSCT) with reference to invasive coronary angiography in the diagnosis of coronary artery disease (CAD) on a per-patient as well as on a per-segment basis. MATERIALS AND METHODS: Thirty-five patients with known or suspected CAD underwent both DSCT (Somatom Definition, Siemens Medical Solutions) and quantitative x-ray coronary angiography (QCA). Parameters of CT acquisition were gantry rotation time 0.330 seconds (ie, temporal resolution 83 milliseconds), tube voltage 120 kV, tube current 560 mA with ECG-triggered tube current modulation and full current at 70% of the cardiac cycle for heart rates below 70 beats per minute or full current between 30% and 80% for higher and arrhythmic heart rates. The pitch was also adapted to the heart rate, ranging from 0.2 to 0.43. Volume and flow rate of contrast material (Ultravist 370, Schering AG) were adapted to the patient's body weight. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DSCT in the detection or exclusion of significant CAD (ie, stenoses >50%) were evaluated on a per-patient and per-segment basis. RESULTS: All 35 CT angiograms were of diagnostic image quality. QCA demonstrated significant CAD in 48% (n = 17) and nonsignificant disease or normal coronary angiograms in 52% (n = 18) of the patients. Sensitivity, specificity, PPV, and NPV of DSCT on a per-patient basis were 100%, 89%, 89%, and 100%, respectively. On a per-segment basis, 473 of 481 coronary artery segments were assessable (98%). QCA demonstrated stenoses >50% in 32 segments (7%), and no disease or nonsignificant disease in 433 segments (93%). For the detection of stenoses >50% on a per-segment basis, DSCT showed a sensitivity, specificity, PPV, and NPV of 88%, 98%, 78%, and 99%, respectively. CONCLUSIONS: The comparison of coronary DSCT with QCA shows a very robust image quality and a high diagnostic accuracy in a patient-based as well as a per-segment analysis. Maximal sensitivity and NPV in the per-patient analysis show the strength of the technique in ruling out significant CAD.     

Does coronary calcium score zero reliably rule out coronary artery disease in low-to-intermediate risk patients? A coronary CTA study

BackgroundObjective was to assess if coronary calcium score (CCS) zero (<1.0AU) reliably rules out coronary artery disease (CAD) by coronary CTA; and if a difference between CCS zero and ultralow CCS (0.1–0.9AU) exists.Methods6439 low-to-intermediate ASCVD-risk patients (57.9 ± 11.1 years; 44.4% females) who underwent CTA and CCS were enrolled. Coronary CTAs were evaluated for: (1) stenosis severity (CADRADS: <25%, 25–49%, 50–69%, 70–99%, and 100%), (2) mixed-plaque burden, and (3) high-risk-plaque-(HRP)-criteria. Primary endpoints were all-cause and cardiovascular (CV) mortality, secondary endpoint MACE.ResultsOverall 1451 (22.5%) had CCS<1.0 AU. Among them, 1289 had CCS zero and 162 ultralow CCS (0.1–0.9AU). In CCS zero patients, 25.9% had CAD, 5.1% > 50% and 20.8% less than 50% stenosis, 6.8% had HRP with min 2 criteria, respectively. LAP<30HU, LAP<60HU, Napkin-Ring-Sign, Spotty calcification and PR were found in 1.3%, 3.7%, 2.8%, 2.3% and 8.2%.CAD prevalence was with 87.7% markedly higher in the ultralow CCS (p < 0.001) group, >50% stenosis (16.6%), total plaque burden (p < 0.001) and HRP-criteria rates were higher (up to 19.1%) (p < 0.001, respectively).All-cause mortality was similar (2.7% and 1.9%) in CCS 0 and ultralow patients (mean follow-up 6.6 ± 4.2 years). Composite MACE (n = 7, 0.48%) was higher than CV-mortality (n = 1, 0.06%, p = 0.038, OR 1.08–1.6). More HRP were found on 128-slice-dual-source-CTA compared to 64-slice (p < 0.001). There were no differences in CTA findings between patients with and without chest pain, but more females were symptomatic.ConclusionEarly signs of CAD on CTA are frequent in CCS zero and even present in the majority of ultralow CCS (0.1–0.9AU) patients, who should not be downgraded to CCS zero patients. High-risk plaque and >50% stenosis rate is low but not negligible; and MACE rate very low.     

Aortic atherosclerosis detected with electron-beam CT as a predictor of obstructive coronary artery disease

RATIONALE AND OBJECTIVES: Several studies have demonstrated an association between coronary and aortic atherosclerosis. Aortic atherosclerosis is easily quantified by means of electron-beam computed tomography (CT). The aim of this study was to evaluate the usefulness of measurement of aortic atherosclerosis with electron-beam CT as an independent predictor of obstructive coronary artery disease (CAD). MATERIALS AND METHODS: Ninety-seven patients (67 men, 30 women; mean age, 61 years +/- 12) were enrolled and underwent electron-beam CT with and without contrast material. Coronary artery calcification was quantified with nonenhanced electron-beam CT by means of Agatston score. CAD was defined as luminal narrowing of the coronary artery by at least 70%, as measured with electron-beam angiography. Aortic atherosclerosis was quantified by measuring raised lesions of the aortic wall (plaque) and wall thickening (volume and thickness) in the midportion of the descending thoracic aorta (10 contiguous sections), as depicted at contrast material-enhanced CT angiography. RESULTS: Aortic plaque and calcification were detected only in patients who were at least 58 years old. The presence of aortic plaque was predictive of obstructive CAD, independent of coronary artery calcification. The sensitivity of aortic plaque (raised lesions) for obstructive CAD was 89% in patients at least 58 years old, and the specificity was 63%. Aortic calcification had a sensitivity of 56% and a specificity of 72% for diagnosis of obstructive CAD. CONCLUSION: This study demonstrated that aortic plaque detected with contrast-enhanced electron-beam CT was a more consistent predictor of obstructive CAD than other independent aortic variables. Aortic calcification depicted on nonenhanced CT images was highly specific for obstructive CAD.     

Triage of patients with suspected coronary artery disease using multislice computed tomography

RATIONALE AND OBJECTIVES: Several studies have shown that multislice computed tomography (MSCT) has a high sensitivity and specificity for detecting coronary artery stenoses. The aim of the present study was to investigate whether MSCT can reliably triage patients with suspected coronary artery disease (CAD) to coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), or no revascularization. MATERIALS AND METHODS: A total of 123 patients with suspected CAD who were referred for conventional coronary angiography (CATH) additionally underwent MSCT (16*0.5 mm detector collimation). Therapeutic decisions made on the basis of CATH and MSCT strictly following current guidelines for treatment of CAD were compared with decisions made by a cardiac surgeon and an interventional cardiologist. Only MSCTs with at least adequate image quality in all coronary segments were included in the analysis (94/123). RESULTS: Decisions made on the basis of MSCT and CATH according to guidelines did not differ significantly (agreement of 88%, 82 of 94, P = .319). The therapeutic decisions made by the interventional cardiologist and the cardiac surgeon based on CATH differed significantly (overall agreement of 79%, 74 of 94 cases, P < .001; cardiologist: 78% PCI and 22% CABG versus surgeon: 38% PCI and 62% CABG), whereas there was 100% agreement regarding decisions for or against invasive treatment. CONCLUSIONS: MSCT shows good agreement with CATH in triaging patients with suspected CAD to CABG, PCI, or no revascularization. The choice of revascularization procedure is significantly more strongly influenced by whether an interventional cardiologist or a cardiac surgeon makes the decision than by the diagnostic test on which the decision is based.     

CT冠状动脉成像在冠心病诊断中的应用

目的:研究CT冠状动脉成像在冠心病早期诊断冠状动脉狭窄定性定量判读的作用。方法:对34例临床未发生急性冠脉综合征的冠心病患者,先后进行冠状动脉造影、128排双源CT冠状动脉成像。以冠状动脉造影为"金标准",计算CT冠状动脉成像敏感性、特异性、阳性预测值、阴性预测值。结果:①与冠状动脉造影相比,CT冠状动脉成像的敏感性为68%,特异性为97%,阳性预测值为89%,阴性预测值为90%。②CT冠状动脉成像有65个血管段图像质量差,约占12%,造成图像质量差的原因主要为钙化,心跳、呼吸伪影,少部分为管腔显示不良。结论:冠心病早期诊断中,CT冠状动脉成像可用作冠状动脉造影前筛选,CT冠状动脉成像阴性的患者不必行冠状动脉造影检查;CT冠状动脉成像阳性的患者,可行冠状动脉造影进一步确认病变。     

Diagnostic performance of stress perfusion and delayed-enhancement MR imaging in patients with coronary artery disease

PURPOSE: To prospectively determine the accuracy of a combined magnetic resonance (MR) imaging approach (stress first-pass perfusion imaging followed by delayed-enhancement imaging) for depicting clinically significant coronary artery stenosis (> or = 70% stenosis) in patients suspected of having or known to have coronary artery disease (CAD), with coronary angiography serving as the reference standard. MATERIALS AND METHODS: The committee on human research approved the study protocol, and all participants gave written informed consent. This study was HIPAA compliant. Forty-seven patients (38 men and nine women; mean age, 63 years +/- 5.3 [standard deviation]) scheduled for coronary angiography were prospectively enrolled: 33 were suspected of having CAD (group A) and 14 had experienced a previous myocardial infarction and were suspected of having new lesions (group B). The MR imaging protocol included cine function, gadolinium-enhanced stress and rest first-pass perfusion MR imaging, and delayed-enhancement MR imaging. Myocardial ischemia was defined as a segment with perfusion deficit at stress first-pass perfusion MR imaging and no hyperenhancement at delayed-enhancement imaging. Myocardial infarction was defined as an area with hyperenhancement at delayed-enhancement imaging. RESULTS: One patient was excluded from analysis because of poor-quality MR images. Coronary angiography depicted significant stenosis in 30 of 46 patients (65%). In a per-vessel analysis (n = 138), stress first-pass perfusion MR imaging and delayed-enhancement imaging yielded sensitivity of 0.87, specificity of 0.89, and accuracy of 0.88, when compared with coronary angiography. The diagnostic accuracy of stress first-pass perfusion MR imaging and delayed-enhancement imaging was slightly better than that of stress and rest first-pass perfusion MR imaging in the entire population (0.88 vs 0.85), in group A (0.86 vs 0.82), and in group B (0.93 vs 0.90). CONCLUSION: Stress first-pass perfusion MR imaging followed by delayed-enhancement imaging is an accurate method to depict significant coronary stenosis in patients suspected of having or known to have CAD.     

Spectrum of collateral findings in multislice CT coronary angiography

PURPOSE: The aim of the study was to investigate the prevalence of the noncardiac collateral findings during multislice computed tomography coronary angiography (MSCT-CA). MATERIALS AND METHODS: Six hundred and seventy patients undergoing MSCT-CA with 16-slice and 64-slice CT scanners for suspected atherosclerotic disease of the coronary arteries were retrospectively reviewed. All data sets obtained with a large field of view (FOV) were analysed by two radiologists using standard mediastinal and lung window settings. Collateral findings were divided according to clinical importance into nonsignificant, remarkable and compulsory to be investigated. RESULTS: Eighty-five percent of patients revealed coronary artery disease (CAD). Only 138/670 (20.6%) were without any additional finding. An additional 1,234 findings were recorded: nonsignificant 332 (26.9%), mild 821 (66.53%), compulsory for study 81 (6.56%). A total of 81 patients (12.08%) had significant noncardiac pathology requiring clinical or radiological follow-up. Among these, newly discovered pathologies were revealed in two patients (2.46%). CONCLUSIONS: A significant number of noncardiac findings might have been missed in MSCT-CA scans; the appropriate approach should be as a team trained in cardiology and radiology.     

Coronary 64-slice CT angiography predicts outcome in patients with known or suspected coronary artery disease

The aim of this study was to assess the prognostic value of 64-slice CT angiography (CTA) in patients with known or suspected coronary artery disease (CAD). Sixty-four-slice coronary CTA was performed in 220 patients [mean age 63 ± 11 years, 77 (35%) female] with known or suspected CAD. CTA images were analyzed with regard to the presence and number of coronary lesions. Patients were followed-up for the occurrence of the following clinical endpoints: death, nonfatal myocardial infarction, unstable angina, and coronary revascularization. During a mean follow-up of 14 ± 4 months, 59 patients (27%) reached at least one of the predefined clinical endpoints. Patients with abnormal coronary arteries on CTA (i.e., presence of coronary plaques) had a 1st-year event rate of 34%, whereas in patients with normal coronary arteries no events occurred (event rate, 0%, p < 0.001). Similarly, obstructive lesions (≥50% luminal narrowing) on CTA were associated with a high first-year event rate (59%) compared to patients without stenoses (3%, p < 0.001). The presence of obstructive lesions was a significant independent predictor of an adverse cardiac outcome. Sixty-four-slice CTA predicts cardiac events in patients with known or suspected CAD. Conversely, patients with normal coronary arteries on CTA have an excellent mid-term prognosis.     

Flow-mediated vasodilation predicts the presence and extent of coronary artery disease assessed by stress thallium imaging

BACKGROUND: Endothelial function can be measured by flow-mediated vasodilation (FMD) of the brachial artery and has been associated with cardiac risk factors (RF) and angiographically defined coronary artery disease (CAD). Stress single photon emission computed tomography (SPECT) imaging is commonly used to study patients with CAD. We sought to study the relationship between endothelial dysfunction by FMD and stress thallium SPECT to detect CAD. METHODS AND RESULTS: Fifty-five consecutive patients with chest pain syndrome referred for stress SPECT and eleven healthy control subjects had FMD measured on the brachial artery by standard techniques. The main outcome was the percent of brachial artery diameter dilation from baseline and the number of perfusion defects by SPECT. In subjects with no RF, those with RF but no defects, and those with defects, the mean FMD was 18.88% +/- 2.31%, 7.85% +/- 1.66%, and 5.91% +/- 1.07%, respectively (P < .05). A significant correlation was found between the number of thallium defects and degree of FMD impairment (r = -0.40, P < .01). An FMD cutoff value of less than 7.5% had a 72.5% sensitivity and 73.1% specificity in predicting the presence of any thallium defects. After RF adjustment, FMD remained as the strongest predictor of scintigraphic CAD (odds ratio, 10.96; 95% confidence interval, 2.82-57.31). CONCLUSION: FMD independently predicts the presence and extent of scintigraphic CAD.     

How accurate is atherosclerosis imaging by coronary computed tomography angiography?

Invasive coronary plaque imaging such as intravascular ultrasound and optical coherence tomography has been widely used to observe culprit or non-culprit coronary atherosclerosis, as well as optimize stent sizing, apposition and deployment. Coronary computed tomographic angiography (CTA) is non-invasively available to assess coronary artery disease (CAD) and has become an appropriate strategy to evaluate patients with suspected CAD. Given recent technologies, semi-automated plaque software is available to identify coronary plaque stenosis, volume and characteristics and potentially allows to be used for the assessment of more details of plaque information, progression and future risk as a surrogate tool of the invasive imaging modalities. This review article aims to focus on various evidence in coronary plaque imaging by coronary CTA and describes how accurate coronary CTA can classify coronary atherosclerosis.     

Prognostic outcome of routine clinical noninvasive multidetector-row computed tomography coronary angiography in patients with suspected coronary artery disease: a 2-year follow-up study

Purpose

The aim of the study was to assess the prognostic value of multidetector-row CT coronary angiography (MDCT-CA) in patients with suspected coronary artery disease (CAD) in a routine clinical context.

Materials and methods

A total of 125 patients (82 men, age 57.4±10.3 years) with suspected CAD underwent MDCT-CA. All patients were assessed for cardiovascular risk factors, symptoms and coronary calcium score. A 2-year follow-up study for the occurrence of major adverse cardiac events was performed.

Results

According to the Morise pretest score, 76 patients (60.8%) were at intermediate risk. Patients with suspected CAD presented the following prognostic outcome (p<0.0001): in 41 patients with normal coronary arteries at MDCT-CA, the event rate was 0%; five of 49 patients with nonobstructive CAD had major cardiac events; two of 35 patients with obstructive CAD suffered cardiac death and 19 underwent revascularisation. At multivariate analysis, the presence of obstructive CAD is the only significant independent prognostic variable (hazard ratio, 10.1393; 95% confidence interval 3.2189?C31.9379; p<0.0001).

Conclusions

Routine clinical MDCT-CA provides an excellent prognostic value at 2-year follow-up in patients with normal coronary arteries. The cardiac event rate increases with CAD severity.     

舟山地区患者股动脉粥样硬化与冠心病关系

目的研究舟山地区患者股动脉粥样硬化与冠心病的关系。方法对300例冠状动脉造影的舟山地区患者作双侧股动脉超声检查,根据冠脉造影结果分为正常组及冠心病组,冠心病组根据冠状动脉病变支数分为一、二、三支病变组(3个亚组)。测量股动脉后壁内中膜厚度(IMT)、斑块厚度及粥样斑块发生率。结果(1)冠心病组IMT,斑块积分及斑块发生率明显高于正常对照组(P<0.01)。(2)随冠脉病变支数增加,斑块积分及IMT增加,亚组间比较差异有显著性(P<0.01)。(3)以IMT>0.85mm和(或)出现粥样斑预测冠心病,特异性75.5%,敏感性86.1%,阳性预测率87.9%。结论舟山地区患者股动脉粥样硬化严重程度与冠心病发生率成正比;通过股动脉超声检查可为冠心病的诊断提供依据。