Tc-99m tetrofosmin myocardial SPECT perfusion imaging: comparison of rest-stress and stress-rest protocols

Aim. The purpose of this study was to evaluate the diagnostic value of Tc-99m tetrofosmin SPECT myocardial perfusion scintigraphy rest/stress and stress/rest protocols for the assessment of coronary artery disease (CAD). Methods. 65 patients underwent both rest and stress SPECT imaging in a one-day protocol and coronary angiography within 2 months before or after scintigraphy. Scintigraphic data was obtained according to two different protocols; 1) rest-stress (n=18) and 2) stress-rest (n=47). Results. Scintigraphic evidence for myocardial ischaemia was found in 36 patients (55%). The overall sensitivity to detect CAD (>50% luminal stenosis) was 94% (34/36), specificity 66% (19/24), positive predictive value 77%, negative predictive value 90%. The sensitivity to detect CAD for protocols 1 and 2 were 100% and 93%, specificity 56% and 70%, positive predictive value 69% and 81% and negative predictive value 100% and 88%, respectively. The left anterior descending coronary artery showed a sensitivity (overall, protocol 1 & 2) of 78%, 75% (3/4) and 79% (15/19) and a specificity of 71%, 64% (9/14) and 75% (21/28). The right coronary artery showed a sensitivity (overall, protocol 1 & 2) of 91%, 100% (6/6) and 88% (14/16) and a specificity of 70%, 92% (11/12) and 61% (19/31). The left circumflex coronary artery showed a sensitivity (overall, protocol 1 & 2) of 50%, 67% (2/3) and 46% (6/13) and a specificity of 94%, 100% (15/15) and 91% (31/34). Conclusion. Tc-99m tetrofosmin appears to be a valuable tool in predicting significant CAD. The sensitivity and the positive predictive value are high, making this test highly appropriate for the diagnosis of CAD. The diagnostic value of the individual coronary arteries is high to moderate. No significant differences were found between both protocols.     

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.     

Comparison of optimised planar scintigraphy with SPECT thallium, exercise ECG and angiography in the detection of coronary artery disease

Background: Thallium SPECT has been shown to be more sensitive than planar imaging in the detection of coronary heart disease (CAD) in a number of reported series. Early (< 10 minutes) redistribution on planar imaging has been demonstrated in clinical studies and this may partly contribute to its lower sensitivity. Aim: To determine whether thallium SPECT is superior to planar scintigraphy (with the timing of imaging performed optimally so that it was commenced within five minutes of injection) in the detection of CAD. Methods: Planar and SPECT studies were performed in 44 patients with significant (>70% stenosis) CAD, seven patients with borderline stenoses (50–69%) and in 18 patients with no significant CAD. Results: The sensitivity of planar imaging was 66% which was higher than exercise ECG 54% (ns) but significantly lower than SPECT 86% (ρ<0.005). The specificity of planar thallium scintigraphy was 100% which was higher than SPECT (83%) and significantly higher than exercise ECG 72% (ρ<0.05). SPECT had a significantly higher sensitivity for LAD and single vessel disease than planar imaging and this was unrelated to a history of prior myocardial infarction. Conclusion: Even when planar imaging is timed optimally to minimise the impact of early redistribution, SPECT is more sensitive than either planar imaging or exercise ECG in the detection of CAD, but its specificity is lower.     

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.     

Dipyridamole-atropine stress echocardiography versus exercise SPECT scintigraphy for detection of coronary artery disease in hypertensives with positive exercise test

OBJECTIVES: Many different stress echocardiographic and radionuclide perfusion imaging tests have been proposed for detecting epicardial coronary artery disease (CAD) in hypertensive patients. Their relative diagnostic and prognostic value has not been exactly established. BACKGROUND: A positive exercise electrocardiography test has a low diagnostic specificity in hypertensive patients and warrants for a complementary imaging test to confirm the diagnosis of coronary artery disease. METHODS: Hypertensive patients (n = 53), (29 males, aged 58 +/- 10 years) with normal left ventricular function detected by echocardiography and previous positive exercise test ( > or = 0.15 mV of ST segment depression on 12 lead electrocardiogram) underwent dipyridamole-atropine stress echocardiography (DASE) and thallium-201 stress/ rest myocardial single-photon emission computed tomography (SPECT). All patients had coronary angiography within 15 days and independently of imaging test results. RESULTS: Coronary angiogram showed significant ( > or = 50% qualitatively assessed diameter reduction) epicardial coronary artery disease in 23 (43%) patients. Sensitivity for detection of coronary artery disease was significantly higher for scintigraphy (DASE = 78% versus SPECT = 100%, P < 0.05) while specificity was higher for echo (DASE = 100% versus SPECT = 47%, P < 0.00001). Diagnostic accuracy was also higher for echo (DASE = 91% versus SPECT = 70%, P < 0.01). CONCLUSION: In patients with exercise-nduced ST segment depression, dipyridamole stress echo and SPECT perfusion scintigraphy are both good diagnostic options, with DASE characterized by higher specificity, lower sensitivity, and at least comparable diagnostic accuracy than SPECT.     

锝-氮-氮欧乙替心肌灌注显像对冠心病的诊断评价

目的评价锝-氮-氮欧乙替（^99mTc-N—NOET）心肌灌注显像检测冠心病的价值。方法对42例临床疑诊冠心病患者,行^99mTc-N-NOET运动负荷和再分布心肌灌注显像,所有患者行冠状动脉造影检查。结果在42例患者中,26例冠状动脉造影显示有冠状动脉狭窄病变,其中单支病变10例,二支病变7例,三支病变9例.^99mTc-N-NOET心肌显像检出心肌缺血或心肌梗死21例,未检出异常5例;16例冠状动脉造影正常患者,^99mTc-N-NOET心肌显像正常14例,异常2例.^99mTc-N-NOET心肌灌注显像诊断冠心病的敏感性为81％、特异性为88％、阳性预测值91％,阴性预测值74％,预测准确性为83％。诊断单支、二支和三支冠状动脉病变的敏感性分别为60％（6／10）、86％（6／7）、100％（9／9）。42例均无干扰心肌分辨的肺、肝重度摄取增高者。15min运动负荷显像肺脏摄取高,尤以冠状动脉狭窄患者增高明显。结论 ^99mTc-N-NOET心肌灌注显像检测冠心病敏感性、特异性较高,早期显像肺摄取增加与有意义的冠状动脉病变有关。     

Prospective Comparison of FFR Derived From Coronary CT Angiography With SPECT Perfusion Imaging in Stable Coronary Artery Disease: The ReASSESS Study

Objectives

This study sought to compare the per-patient diagnostic performance of coronary computed tomography angiography (CTA)-derived fractional flow reserve (FFR_CT) with that of single-photon emission computed tomography (SPECT), using a fractional flow reserve (FFR) value of ≤0.80 as the reference for diagnosing at least 1 hemodynamically significant stenosis in a head-to-head comparison of patients with intermediate coronary stenosis as determined by coronary CTA.

Integrated single-photon emission computed tomography and computed tomography coronary angiography for the assessment of hemodynamically significant coronary artery lesions.

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

ATP负荷及运动负荷试验中心电图的变化对冠心病的诊断价值

目的探讨ATP负荷及运动负荷心肌灌注单光子发射计算机体层摄影术(SPECT)中的ECG变化及其对冠心病的诊断价值。方法选择61例疑诊冠心病的患者,并在不同时间分别行ATP负荷及运动负荷SPECT检查,其中46例行冠状动脉造影。收集ATP及运动负荷试验中的ECG资料并进行分析。结果ATP与运动负荷试验中ECG心律失常的发生情况相似(χ2=1.985,P=0.159);ATP负荷试验ST段下降发生率明显低于运动负荷试验(12.5%vs51.8%,χ2=19.813,P<0.001),且下降幅度低。ATP负荷试验ECG诊断冠心病的敏感性明显低于运动负荷试验(28.6%vs71.4%,χ2=7.714,P=0.005),特异性、阳性预测值及阴性预测值与运动负荷试验相似(95.2%vs71.4%,85.7%vs71.4%,57.1%vs71.4%,P>0.05)。结论与运动负荷试验比较,ATP负荷试验ECG诊断冠心病的敏感性低,但特异性及阳性预测值相对较高。     

Dipyridamole body surface potential mapping: noninvasive differentiation of syndrome X from coronary artery disease

Up to 20% to 30% of patients with angina and abnormal stress test have normal coronary arteries at angiography or syndrome X (Sy X). We tested whether body surface potential mapping (BSPM) with intravenous dipyridamole could differentiate patients with Sy X from patients with coronary artery disease (CAD). We compared the effects of intravenous dipyridamole (0.28 mg/kg over 4 min) on BSPM in 17 healthy volunteers (controls) and in 2 groups of patients with angina and abnormal ergometric tests who were referred for angiography: 27 patients with obstructive disease (> or =70% diameter stenosis) in the CAD group, and 17 patients with Sy X. Control subjects were easily differentiated from patients with CAD or Sy X by markedly smaller baseline BSPM DeltaST-T < or = LSD departure areas (P <.001), but the Sy X and CAD groups had similar ST-T departure areas. The average potential integral difference after dipyridamole (APID) differentiated Sy X and CAD patients: the mean APID increased in patients with Sy X and trended negative in the CAD group. The APID(20%-40%) (integrated over 20% to 40% of the ST-T interval) mean value was 0.59 +/- 0.67 microVs in the Sy X group and -0.18 +/- 0.59 microVs in the CAD group (P <.01). At a threshold APID(20%-40%) > 0.17 microVs, the sensitivity and specificity for Sy X was 71% and 78%, respectively; the area under the receiver operating characteristic curve was 0.79 (95% CI 0.64, 0.93). Dipyridamole BSPM is a promising noninvasive diagnostic modality to differentiate patients with Sy X from those with CAD.     

99mTc-MIBI门电路SPECT对冠心病的诊断和心肌存活性评价的作用

为进一步评价99m锝-甲氧基异睛(99mTc-MIBI)门电路和非门电路单光子发射断层显像(SPECT)对冠心病的诊断价值及硝酸甘油介入诊断试验在心肌存活状态评价中的作用,对40例进行运动心肌灌注断层显象,并与冠状动脉(冠脉)造影比较.结果32例冠脉造影显示冠脉有意义狭窄.门电路断层显象对冠心病诊断总的敏感和特异性分别为93.8%和87.5%;非门电路断层显象分别为84.4%和87.5%,两相比较,无显著性差异(P＞0.05).对冠脉病变支数诊断敏感性门电路方法优于非门电路方法(分别为73.8%和62.3%,P＜0.05).特异性均为96.6%.20例进行含服硝酸甘油后静态心肌灌注断层显象,16例心肌梗死病人中有3例为部分可逆性心肌灌注缺损,4例慢性心肌缺血病人,全部有可逆性心肌灌注.表明硝酸甘油介入诊断试验有助于心肌灌注异常可逆性的评估;99mTc-MIBI门电路SPECT和硝酸甘油介入诊断试验是有效的对冠心病无创性诊断和心肌存活状态评价方法.     

201Tl运动负荷心肌显像、运动负荷心电图在冠心病诊断中的价值

目的:评价201Tl运动负荷心肌灌注显像(MPI),运动负荷心电图(ES-ECG)诊断冠心病(CAD)的临床价值。方法:首先以冠状动脉造影术(CAG)为标准(将冠脉管腔狭窄≥50%定为病变血管),96例做过CAG的患者被分为CAD组(n=55)和非CAD组(n=41)。所有患者均行运动负荷MPI和ES-ECG检查。对比分析运动负荷MPI和ES-ECG诊断CAD的灵敏度、特异性、准确性、阳性预测值。结果:运动负荷MPI和ES-ECG诊断CAD的敏感性分别为0.98、0.82;特异性分别为0.85、0.39;准确性分别为0.92、0.64;阳性预测值分别为0.90、0.64;阴性预测值分别为0.97、0.62。结论:运动负荷MPI与CAG有较好的一致性,而ES-ECG是一种较好的筛查方法。     

Dobutamine stress echocardiography compared with dipyridamole thallium-201 single-photon emission computed tomography in detecting coronary artery disease

To compare the diagnostic value of dobutamine stress echocardiographywith dipyridamole thallium-201 single-photon emission computedtomography (SPECT) in detecting coronary artery disease (CAD),we performed both tests on 54 patients who also underwent coronaryarteriography. Dobutamine was infused at an incremental regimenof 5,10,20,30 and 40 µg. kg^-1. min^-1. Dipyridamole wasinfused at a rate of 0.14 mg. kg^-1. min^-1 over 4 min. Dobutaminestress echocardiography detected 40 (93%) and SPECT 42 (98%,P=ns) of the 43 patients with significant CAD, defined as (greaterthan or equal) 50% diameter stenosis. The specificity was 73%(8 of 11) for both tests. The sensitivity for detecting individualcoronary artery stenosis with dobutamine stress echocardiographywas 81% (30 of 37) for the left anterior descending artery,75% (24 of 32) for the right coronary artery, and 61% (17 of28) for the left circumflex artery. For SPECT it was 89%, 97%(P>0.05 vs dobutamine stress echocardiography) and 75%, respectively. Among the 97 stenotic coronary arteries, 17 had mild to moderatestenosis (50%-69% diameter stenosis) and 80 had severe stenosis($$70% diameter stenosis). With dobutamine stress echocardiography,53% of the arteries with mild to moderate stenosis were identifiedvs 78% of those with severe stenosis (P<0.05). With SPECT,the sensitivity was 82% (14 of 17) in mild to moderate stenosisand 89% (71 of 80) in severe stenosis (P=ns). No major sideeffects occurred during either test. Thus, both dobutamine stressand SPECT are highly sensitive for detection and localizationof CAD. However, the sensitivity of dobutamine stress is affectedby the level of stenosis severity.     

Prediction of coronary artery lesions in unstable angina by iodine 123 beta-methyl iodophenyl pentadecanoic acid (BMIPP), a fatty acid analogue, single photon emission computed tomography at rest.

Iodine 123 beta-methyl iodophenyl pentadecanoic acid (123I-BMIPP), a beta-methyl-branched fatty acid analogue, has been proven by experimental studies to reveal abnormalities in fatty-acid-related metabolism. This study was undertaken to validate the accuracy and limitations of 123I-BMIPP imaging at rest in detecting myocardial metabolic abnormalities and predicting coronary lesions in unstable angina (UA). One hundred UA patients without prior myocardial infarction were studied. 123I-BMIPP and thallium 201 chloride (201TlCl) imaging with single photon emission computed tomography (SPECT) and coronary and left ventricular cineangiography (LVC) were performed 1 week after the last episode of angina. There was reduced uptake of 123I-BMIPP imaging in 70 patients, reduced uptake of 201TlCl in 41, and abnormal LVC contraction in 49 patients. There were significant increases in severity scores of 123I-BMIPP imaging along with increases in the number of stenosed coronary arteries and the severity of stenosis in individual coronary arteries. There was a significant reduction in 123I-BMIPP severity scores 1 month after percutaneous transluminal coronary angioplasty (p < 0.01) and a significant correlation between the severity scores of 123I-BMIPP and LVC (r=0. 579, p<0.001). Overall rates of sensitivity and specificity in detecting significant coronary stenosis by 123I-BMIPP imaging were 74% and 86%, respectively, whereas rates of sensitivity and specificity in detecting significant coronary stenosis by 201TlCl were 31% and 91%, respectively. 123I-BMIPP sensitivity increases to 86% if only advanced coronary stenosis of >90% is included. In conclusion, 123I-BMIPP myocardial imaging is an effective method of predicting coronary artery lesions of UA patients without provocative test.     

Differentiating Between Acute Decompensated Aortic Stenosis and Myocardial Infarction

BackgroundPatients with aortic stenosis (AS) are susceptible to myocardial ischemia and often present acutely, making it challenging to differentiate between a type 1 NSTEMI and acute decompensated aortic stenosis. This study aims to evaluate the diagnostic accuracy of Troponin T (TnT) (>5 fold above the upper limit of normal), ischemic ECG and angina, to predict a type 1 non-ST elevation myocardial infarction (NSTEMI) and obstructive coronary artery disease (CAD) among patients with severe AS and acute presentations.MethodsPatients with severe AS and acute symptoms: angina (Canadian Cardiovascular Society Class 3/4), dyspnea (New York Heart Association 4) and/or syncope were included. The endpoints were a type 1 NSTEMI defined by the presence of a coronary thrombus or > 90% stenosis and obstructive CAD defined as >70% stenosis, by computed tomography (CT) and/or invasive coronary angiography (ICA).ResultsOut of 273 patients, 6.2% had a type 1 NSTEMI. Positive TnT, ischemic ECG and angina demonstrated negative predictive values of 95%, 94% and 97% respectively and positive predictive values of 12%, 9% and 13% respectively. Specificity increased with all three metrics (95%), whilst sensitivity and positive predictive value reduced (18% and 19% respectively). 39.2% of patients had obstructive CAD. Positive TnT, ischemic ECG and angina demonstrated sensitivity of 64%, 34% and 41% respectively and specificity of 57%, 77% and 77% respectively.ConclusionsAngina, ischemic ECG and positive TnT are common among patients with AS presenting acutely and often not associated with a type 1 NSTEMI. These metrics, if positive, cannot reliably differentiate between a type 1 NSTEMI and acute decompensated AS. Coronary imaging using either CT or ICA is necessary to make a definitive diagnosis of a type 1 NSTEMI in patients with severe AS.     

Diagonal earlobe crease as a marker of the presence and extent of coronary atherosclerosis.

This study evaluates the association between the presence of diagonal earlobe creases (ELC) and coronary artery disease (CAD). One thousand four hundred twenty-four patients (760 men and 664 women, aged 30 to 80 years) were examined for the presence of ELC and classified into 2 groups: group I control--1,086 consecutive patients who denied symptoms of myocardial ischemia and were admitted to a general hospital for other reasons; group II CAD--338 patients with documented CAD (presence of > or = 70% coronary diameter stenosis at angiography). ELC was present in 304 patients (28%) in group I and 220 (65%) in group II (p < 0.0001). The patients were stratified in age groups to isolate the influence of age because the prevalence of ELC and CAD increased with advancing age (p < 0.0001 for both). This association remained statistically significant in all decades, except for patients aged > 70 years. To further remove the confounding effect of different age and sex distributions between the groups, a direct adjustment of the ELC prevalence was performed. When adjusted for age and sex, the prevalence of creases was still 58% higher in patients with CAD than in control subjects (p < 0.001). The presence of ELC was also related to the extent of CAD as measured by the number of major arteries narrowed (p = 0.015). The observed sensitivity of the sign for the diagnosis of CAD was 65%, the specificity 72%, the positive predictive value 42% and the negative predictive value 87%.     

Relationship between CT coronary angiography and stress perfusion imaging in patients with suspected ischemic heart disease assessed by integrated PET-CT imaging.

BACKGROUND: Although computed tomography (CT) coronary angiography (CTA) provides detailed assessments of the anatomic extent of coronary artery disease (CAD), its value for predicting myocardial ischemia is unclear. We examined the value of CTA to identify the presence of ischemia, as determined by stress perfusion imaging, using integrated positron emission tomography (PET)-CT imaging. METHODS AND RESULTS: We studied 110 consecutive patients (median age, 57 years; 55% male) with suspected CAD undergoing stress rubidium 82 myocardial perfusion PET imaging and CTA in the same setting. Increasing degrees of CTA-detected luminal narrowing (<50%, 50%-70%, and >70%) were associated with reduced sensitivity with commensurate improvements in specificity for identifying myocardial ischemia both on a per-vessel basis and on a per-patient basis. Consequently, with increasing degrees of CTA-detected stenosis severity, the positive predictive value increased (14%, 26%, and 53%, respectively, on a per-vessel basis [P < .001] and 29%, 44%, and 77%, respectively, on a per-patient basis [P = .005]), whereas the negative predictive value was unchanged (97%, 97%, and 96%, respectively, on a per-vessel basis [P = not significant (NS)] and 92%, 91%, and 88%, respectively, on a per-patient basis [P = NS]). Receiver operating characteristic analysis revealed no differences between these 3 anatomic criteria (receiver operating characteristic areas of 0.66 +/- 0.07, 0.73 +/- 0.06, and 0.71 +/- 0.07, respectively [P = NS]) for identifying ischemia. Nearly half of significant angiographic stenoses (47%) occurred without evidence of myocardial ischemia, whereas 50% of normal PET studies were associated with some CTA abnormality. CONCLUSIONS: Despite an excellent negative predictive value, CTA is a poor discriminator of patients with myocardial ischemia. Conversely, a normal stress PET study is a poor discriminator of patients without evidence of non-flow-limiting (subclinical) coronary atherosclerosis. These results suggest potentially complementary roles of CT and perfusion imaging in the evaluation of patients with suspected CAD.     

Coronary anatomy predicts presence or absence of renal artery stenosis. A prospective study in patients undergoing cardiac catheterization for suspected coronary artery disease.

AIMS: This study aimed to determine the prevalence of renal artery stenosis (RAS) and associated risk factors in patients undergoing cardiac catheterization for suspected coronary artery disease (CAD). METHODS: One hundred and seventy-seven consecutive patients (62 females) with a serum creatinine concentration <2.0mg.dl(-1) were studied. Abdominal aortography followed cardiac catheterization to screen for RAS. RESULTS: In 110 patients (62%) CAD and in 19 patients (11%) significant RAS (luminal narrowing of >or=50%) were detected, 12 of whom had high grade (>or=70%) RAS, and two subjects had significant RAS without CAD. Patients with RAS were older (67+/-8 vs 61+/-11 years, mean+/-SD;P =0.004), had higher systolic blood pressure (150+/-15 vs 138+/-20 mmHg;P =0.005), a lower glomerular filtration rate (GFR; 61+/-16 vs 80+/-22 ml.min(-1), P<0.001) and more often diabetes mellitus (69% vs 30%; P=0.004). In multivariate analysis a low GFR and the extent of CAD were independent predictors of RAS. The presence of >2 significant coronary lesions predicted RAS (sensitivity 0.84, specificity 0.77, positive predictive value 0.30, negative predictive value 0.98). CONCLUSION: Screening for RAS in patients with >2 diseased coronary segments has a high diagnostic yield, which is even greater in the presence of a reduced GFR, diabetes mellitus, and elevated systolic blood pressure.     

Endothelial functional and structural impairment in patients with different degrees of coronary artery disease development

Flow-mediated dilatation (FMD) and intima-media thickness (IMT) are noninvasive methods for patient evaluation. In this study we aimed to estimate the correlation between FMD and IMT in patients with different degree of coronary artery disease (CAD) development, and to explore their prognostic significance for the presence of angiographically significant coronary artery stenosis. We included 198 patients divided into five groups according to the degree of CAD development. All patients had FMD and IMT measured, 105 (53.03%) performed a Treadmill test in our clinic, and 146 (73.7%) underwent coronary arteriography (CAG). Patients with significant (> or = 50%) coronary artery stenosis had lower FMD and higher IMT values compared to patients without significant CAD: FMD: 2.78% +/- 2.71% vs 8.24% +/- 5.16%, respectively, P < 0.001; IMT: 0.882 +/- 0.17 mm vs 0.763 +/- 0.16 mm, respectively, P < 0.001. There existed a weak negative correlation between FMD and IMT (correlation coefficient: 0.242, P < 0.001), which was lost in subgroups and after controlling for the presence of significant CAD, number of diseased coronary arteries, and percent coronary artery stenosis. Analyzing the receiver operating characteristic curves we found that FMD values < or = 4.5% had 74% sensitivity, 77% specificity, positive predictive value (PPV) 81.8%, and negative predictive value (NPV) 68%, and IMT values > or = 0.81 mm had sensitivity 71%, specificity 67%, PPV 76.1%, and NPV 63.1% for the presence of significant CAD. Patients with advanced CAD had lower FMD and higher IMT values compared to patients with minor changes. The correlation between FMD and IMT was weak and inconsistent. Both methods demonstrated an acceptable prognostic significance for the presence of significant CAD.     

Myocardial contrast echocardiography for the detection of coronary artery stenosis: a prospective multicenter study in comparison with single-photon emission computed tomography.

OBJECTIVES: The purpose of this study was to compare myocardial contrast echocardiography (MCE) with single-photon emission computed tomography (SPECT) for the detection of significant coronary artery disease (CAD) in patients with symptoms suggestive of CAD. BACKGROUND: Single-photon emission computed tomography is a well-established method of assessing patients with CAD. Myocardial contrast echocardiography is a new technique allowing bedside assessment of myocardial perfusion. We hypothesized that MCE was comparable to SPECT in the assessment of patients with known or suspected CAD. METHODS: A total of 123 patients scheduled for coronary angiography underwent intermediate (mechanical index 0.5) triggered replenishment MCE and SPECT imaging at rest and after vasodilator stress. Coronary angiography was performed within four weeks of stress imaging. RESULTS: In total, 96 of 123 (78%) patients demonstrated CAD (stenosis >/=50%). There was no difference in the sensitivity of MCE compared with SPECT in the detection of CAD (84% vs. 82%; p = NS), and both demonstrated similar specificity (56% vs. 52%, respectively). In patients with multivessel disease, MCE and SPECT also demonstrated similar sensitivity (91% and 88%, respectively) for the detection of CAD. Agreement between MCE and SPECT for the presence or absence of CAD was 73%. CONCLUSIONS: Myocardial contrast echocardiography is comparable to SPECT in the detection of CAD not only on a patient basis but also in the localization of disease by vascular territory in a relatively high-risk population.