Higher Prevalence Of Coronary Artery Disease Research Articles

Screening for silent myocardial ischaemia in type 2 diabetic patients with additional atherogenic risk factors: applicability and accuracy of the exercise stress test.

Coronary artery disease (CAD), a major cause of mortality in patients with type 2 diabetes (T2D), is often diagnosed late because of silent myocardial ischaemia (SMI). Exercise electrocardiogram testing (ECG) stress is the most utilized screening test for SMI. Its applicability and accuracy, which have never been reported in asymptomatic high-risk T2D patients, have been investigated in this study. A cross-sectional study with coronary angiography as the gold standard for detecting CAD was used. Two hundred and six consecutive T2D patients, without symptoms and resting ECG signs of ischaemia but with peripheral vascular disease (PVD) and/or > or = two atherogenic factors, were studied. Ischaemia at ECG stress was indicated by horizontal or downsloping ST segment depression > or =1 mm at 0.08 s after the J point. CAD was defined by stenosis > or =70%. Only 141/206 (68%) patients had a diagnostic test: 27 (19%) tested positive and 114 (81%) tested negative. Coronary angiography in 71 patients (the 27 who tested positive and 44 randomly selected patients who tested negative) indicated a CAD prevalence of 29% and the ECG stress accuracy was 79%. 'False negative' patients (18%) had a higher prevalence (P<0.01) of long duration of diabetes and PVD. This is the first study which provides insights into the applicability and accuracy of ECG stress in screening SMI in high-risk patients with T2D. Due to the high prevalence of CAD, alternative screening tests in patients unable to perform the test and in those with a high chance of being 'false negative' should be looked for and validated.

Subclinical hypothyroidism is associated with coronary artery disease in older persons.

We report the prevalence of coronary artery disease (CAD) associated with subclinical hypothyroidism in older persons. We investigated the prevalence of subclinical hypothyroidism and its association with dyslipidemia and with CAD in 170 women and 110 men, mean age 75 +/- 9 years, in an academic nursing home. Of 280 persons, 18 (6%) had subclinical hypothyroidism, 18 (6%) had treated clinical hypothyroidism, 13 (5%) had subclinical hyperthyroidism, and 231 (83%) were euthyroid. Dyslipidemia occurred in 15 of 18 persons (83%) with subclinical hypothyroidism, in nine of 18 persons (50%) treated for hypothyroidism, in six of 13 persons (46%) with subclinical hyperthyroidism, and in 128 of 231 euthyroid persons (55%) (p <.025 comparing subclinical hypothyroidism with euthyroidism and p <.005 comparing subclinical hypothyroidism with treated hypothyroidism and with subclinical hyperthyroidism). CAD was present in 10 of 18 persons (56%) with subclinical hypothyroidism, in nine of 18 persons (50%) with treated hypothyroidism, in 5 of 13 persons (38%) with subclinical hyperthyroidism, and in 38 of 231 euthyroid persons (16%) (p <.001 comparing subclinical hypothyroidism with euthyroidism; p <.005 comparing treated hypothyroidism with euthyroidism; and p <.05 comparing subclinical hyperthyroidism with euthyroidism). Subclinical hypothyroidism was associated with a high prevalence of dyslipidemia and a high prevalence of CAD.

Usefulness of multislice computed tomography for detecting obstructive coronary artery disease

The latest generation of multislice spiral computed tomography (MSCT) scanners is capable of noninvasive coronary angiography. We evaluated its diagnostic accuracy to detect stenotic coronary artery disease (CAD). In 53 patients with suspected CAD, contrast-enhanced MSCT and conventional angiography were performed. The CT data were acquired within a single breathhold, and isocardiophasic slices were reconstructed by means of retrospective electrocardiographic gating. Coronary segments of ≥2 mm in diameter, measured by quantitative angiography, were evaluated. In 70% of the 358 available segments, image quality was regarded as adequate for assessment. The overall sensitivity, specificity, and positive and negative predictive values to detect ≥50% stenotic lesions in the assessable segments were 82% (42 of 51 lesions), 93% (285 of 307 nonstenotic segments), and 66% and 97%, respectively, regarding conventional quantitative angiography as the gold standard. Proximal segments were assessable in 92%, and distal segments and side branches in 71% and 50%, respectively. Including the undetected lesions in nonassessable segments, overall sensitivity decreased to 61% but remained 82% for lesions in proximal coronary segments. MSCT correctly predicted absent, single, or multiple lesions in 55% of patients. Thus, despite potentially high image quality, current MSCT protocols offer only reasonable diagnostic accuracy in an unselected patient group with a high prevalence of CAD.

Angiographic progression of coronary artery disease in patients with end-stage renal disease.

Patients with end-stage renal disease have an increased risk of developing coronary artery disease (CAD). The cardiovascular mortality of dialysis patients is 10-15 times higher compared with the general population. The aim of our study was to evaluate the morphological progression of coronary arteriosclerosis in this cardiovascular high-risk group by visual assessment and quantitative coronary angiography. Methods and results. In 26 patients with chronic renal failure (age, 47+/-11 years; 15 male; duration of dialysis, 23+/-25 months) the severity of CAD and degree of coronary stenoses were assessed in two coronary angiograms after a mean follow-up interval of 30+/-15 months (12-60). Baseline angiography revealed CAD in 13/22 patients (59%). The second angiography was performed as screening procedure prior to renal transplantation (n=20) and/or as follow-up angiography after coronary angioplasty (n=10). Visual assessment showed a progression defined by the development of haemodynamically relevant stenosis of >50% luminal diameter in 13 patients. Quantitative angiographic evaluation was performed in a total of 45 segments showing >25% narrowing at the second angiogram. A progression (>15% luminal reduction) was found in 17 of 45 segments, a new lesion (initial luminal diameter <20%) was detected in nine segments, resulting in progression or new lesion in 16 patients (62%). Patients with or without progression did not differ in age, duration of dialysis treatment, number of cardiovascular risk factors, or serum total cholesterol and fibrinogen levels. After percutaneous transluminal coronary angioplasty (PTCA) a restenosis was seen in seven of 16 primarily successfully dilated segments. After the second angiography, myocardial revascularization was performed in eight patients (1 PTCA, 7 coronary artery bypass graft). Patients with end-stage renal disease have a high prevalence of CAD. In line with the clinical course, CAD patients on maintenance dialysis undergo rapid angiographic progression of CAD, which results in a high rate of subsequent myocardial revascularizations.

Associations between classical cardiovascular risk factors and coronary artery disease in two countries at contrasting risk for myocardial infarction: the PRIME Study

Purpose: In two countries with contrasting risk for coronary artery disease (CAD)—Northern Ireland and France—a case-control study was performed on baseline data within a cohort study to compare the strength of the associations between CAD prevalence and classical risk factors. Method and results: A sample of 9561 men, aged 50–60 years, was studied: 382 had had myocardial infarction or angina, and 9179 were controls. In both countries, variables associated with CAD were age, body mass index, hypertension, diabetes, family history of myocardial infarction (MI), tobacco consumption, triglycerides, HDL-cholesterol, apolipoprotein A-I and B levels. Logistic regression analyses were conducted using standardized odds ratios. The strength of the associations with CAD was rather similar in the two countries (Northern Ireland versus France) for age [1.26 (1.10–1.45) vs. 1.41 (1.17–1.69)], family history of MI [1.50 (1.04–2.15) vs. 1.83 (0.99–3.37)], hypertension [1.49 (1.13–1.97) vs. 1.67 (1.14–2.44)], diabetes [5.42 (2.53–11.60) vs. 2.24 (1.06–4.73)], tobacco consumption [1.43 (1.27–1.60) vs. 1.39 (1.22–1.58)], HDL-cholesterol [0.80 (0.68–0.94) vs. 0.86 (0.70–1.06)] and triglyceride levels [1.17 (1.01–1.36) vs. 1.10 (0.91–1.32)]. Discrepancies concerned lipoprotein(a) [1.22 (1.06–1.40) vs. 0.96 (0.81–1.15), P<0.01], with stronger associations in Northern Ireland than in France. Conclusion: It is concluded that the higher prevalence of CAD in Northern Ireland cannot be explained by major differences in the susceptibility to classical risk factors; the difference in risk of CAD appears mainly related in Northern Ireland to other risk factors including a worse lipid profile and genetic/environmental interactions.

Real-time intraoperative monitoring of myocardial ischemia in noncardiac surgery.

Real-time intraoperative monitoring of myocardial ischemia in noncardiac surgery.

Body Fat Percent by Bioelectrical Impedance Analysis and Risk of Coronary Artery Disease Among Urban Men with Low Rates of Obesity: The Indian Paradox

Objective: To determine the association between body fat percent and prevalence of coronary artery disease (CAD) and coronary risk factors in subjects with low rates of obesity.Subjects and Methods: We randomly selected 850 men, aged 25 to 64 years. The survey methods were questionnaire and bioelectrical impedance analysis for body composition. Subjects were divided into high-fat (n=357), over-fat (n=230), normal-fat (n=200) and under-fat (n=63) based on criteria of body-fat percent analysis.Results: The prevalence of CAD and the coronary-risk factors hypercholesterolemia, hypertension, diabetes, mellitus and sedentary lifestyle were significantly associated with high and moderate body fat percent despite low body-mass index (23.6±4.1 kg/m2). Mean total cholesterol, triglycerides and blood pressure were significantly associated with high and moderate body fat percent. The prevalence of smoking was weakly but inversely associated with high body-fat percent. Mean HDL cholesterol was positively associated with high body-fat percent. Body mass index was positively associated with high body-fat percent.Conclusions: High and moderate body-fat-percent subjects were associated with high prevalence of CAD and the coronary-risk factors hypertension, diabetes mellitus, higher body-mass index and sedentary lifestyle.

Low Fat Intake and Coronary Artery Disease in a Population with Higher Prevalence of Coronary Artery Disease: The Indian Paradox

Objective: To determine the association between saturated fat intake and prevalence of coronary artery disease (CAD) and coronary risk factors.Design and Setting: Total community cross sectional survey of 20 urban streets out of 196 streets, in the city of Moradabad in north India.Subjects and Methods: Adult population between 25 to 64 years inclusive comprised of 1806 subjects (904 men, 902 women) were divided into three groups according to level of saturated fat intake as assessed by 7-day dietary intake records (very low <7%, low 7 to 10%, high >10% energy (en) per day).Results: We examined the relationship between CAD risk and levels of % en from fat intake. Low (7 to 10% en/day) and high (>10% en/day) saturated fat were positively and significantly associated with higher prevalence of CAD. The prevalence of coronary risk factors (hypertension, hypercholesterolemia, obesity and sedentary lifestyle) were significantly higher among subjects with low and high saturated fat intake compared to subjects with very low (<7%) saturated fat intake. Logistic regression analysis with adjustment for age showed that hypercholesterolemia (OR: men 0.89, women 0.68), hypertension (men 0.92, women 0.56), physical activity (men 0.80, women 0.36), obesity (men 0.82, women 0.88) and smoking (0.70 men) were significant risk factors of CAD. Low and high saturated fat intake were associated with more prestigious occupations, higher and middle income status and better educational levels compared to very low saturated fat intake.Conclusions: The prevalence of CAD and coronary risk factors was higher in urban Indians with low and high saturated fat intake than those with lower saturated fat intake. These findings suggest that the saturated fat intake should be <7% en/day for prevention of CAD in Indians.

Social class and coronary artery disease in a urban population of North India in the Indian lifestyle and heart study

Objective: To determine the association of social class with prevalence of coronary risk factors and coronary artery disease (CAD). Design and setting: Total community cross sectional survey of 20 randomly selected streets in the city of Moradabad. Subjects and methods: 1806 urban (904 men and 902 women) randomly selected subjects aged 25–64 years. The survey methods were physician and dietitian administered questionnaire, physical examination and electrocardiography. All subjects were divided into social classes 1–5 based on attributes of education, occupation, per capita income, housing condition and consumer durables and other family assets. Results: Social classes 1, 2 and 3 were mainly high and middle socioeconomic groups and 3 and 4 low income groups. The prevalence of CAD and coronary risk factors hypercholesterolemia, hypertension, diabetes mellitus and. sedentary lifestyle were significantly higher among social classes 1, 2 and 3 in both sexes compared to lower social classes. Mean serum cholesterol, triglycerides, low density lipoprotein cholesterol and blood pressure were significantly associated with higher and middle social classes. Smoking was significantly associated with lower social classes. Multivariate logistic regression analysis after adjustment of age revealed that social class was positively associated with CAD (odds ratio: men 0.84, women 0.86), hypercholesterolemia (men 0.87, women 0.85), hypertension (men 0.91, women 0.89), diabetes mellitus (men 0.71, women 0.68) and sedentary lifestyle (men 0.68, women 0.66). Smoking was significantly associated with CAD in men. Conclusion: Social class 1, 2 and 3 in an urban population of India have a higher prevalence of CAD and coronary risk factors hypercholesterolemia, hypertension, diabetes mellitus and sedentary lifestyle in both sexes.

Apolipoprotein B, fibrinogen, HDL cholesterol, and apolipoprotein(a) phenotypes predict coronary artery disease in hemodialysis patients.

Patients with end-stage renal disease have a markedly elevated risk for coronary artery disease (CAD). Lipids and most lipoproteins, however, seem to be not predictive for CAD in these patients. Although there is clear evidence that lipoprotein(a) [Lp(a)] is significantly elevated in these patients, no study with a sufficiently large group of hemodialysis patients has investigated the relationship between CAD and Lp(a), as well as the genetically determined apolipoprotein(a) [apo(a)] phenotype. This cross-sectional study determines the prevalence of CAD in relation to the cardiovascular risk profile in an unselected population of 607 hemodialysis patients, of which 33% were diabetic patients. Twenty-six percent (n = 158) of all patients suffered from CAD as diagnosed by a definitive myocardial infarction (n = 102) and/or at least one stenosis >50% of a coronary artery (n = 143). In univariate analysis, several classic risk factors, including the concentration of lipids, lipoproteins, apolipoproteins, and fibrinogen, correlated with CAD. Lp(a) in patients with CAD showed only a tendency to higher levels, without reaching significance, compared with patients without CAD (26.6 +/- 30.8 mg/dl versus 22.1 +/- 30.4 mg/dl, P = 0.10). The frequency of low molecular weight apo(a) isoforms, however, was significantly greater in the group with CAD (34.8% versus 23.6%, P < 0.01). Stepwise logistic regression analysis found seven variables associated with CAD: apolipoprotein B, the low molecular weight apo(a) phenotype, male sex, age, fibrinogen, diabetes mellitus, and HDL cholesterol. The association of these variables with CAD differed depending on age. These results indicate that, besides classic risk factors such as age, sex, and diabetes mellitus, additional factors of the lipoprotein and fibrinolytic system contribute to the high prevalence of CAD in hemodialysis patients.

Epidemiologic study of trace elements and magnesium on risk of coronary artery disease in rural and urban Indian populations.

To determine the association of trace elements and magnesium with risk of coronary artery disease (CAD) in rural and urban populations of India.Cross-sectional surveys on the randomly selected municipal streets in Moradabad city and one village in Moradabad tahsil in North India.There were 162 rural (86 men and 96 women) and 152 urban (80 men and 72 women) subjects between 26 to 65 years of age. Evaluations were obtained by physician- and dietitian-administered, validated questionnaires, physical examination, electrocardiogram and blood examination.The prevalence of CAD and coronary risk factors was 2.5 times higher in the urban population compared to rural subjects (8.6 vs. 3.0%). In rural subjects, dietary intakes and plasma levels of vitamins and minerals were comparable with those of urban subjects except for higher dietary intake of magnesium in rural subjects and higher plasma vitamin A level in urban subjects. In both rural and urban subjects, low serum zinc (80 +/− 82 vs. 110 +/− 11.0 micrograms/dl, p < 0.05) and magnesium levels (1.60 +/− 0.36 vs. 1.71 +/− 0.41 mEQ/L, p < 0.05) and lower zinc/copper ratio (0.58 +/− 0.08 vs. 1.11 +/− 0.25 p < 0.50) were inversely associated with CAD. Serum levels of copper and iron were significantly higher and plasma levels of antioxidant vitamins A, E and C and beta-carotene were significantly lower in patients with CAD compared to the rest of the subjects. In both rural (7.1 +/− 1.2 mg/day) and urban subjects (8.6 +/− 1.6 mg/day), zinc consumption was half of the recommended dietary allowances. Higher prevalence of CAD in urban compared to rural subjects was attributed to higher dietary fat intake and higher prevalence of risk factors in urban subjects.The findings suggest that lower serum levels of zinc and magnesium and lower zinc copper ratio were inversely associated with CAD. It is possible that urban populations with higher risk of CAD may benefit by decreasing dietary fat intake and by increasing their intake of foods rich in zinc and magnesium.

Dietary intake, plasma levels of antioxidant vitamins, and oxidative stress in relation to coronary artery disease in elderly subjects

The prevalence of coronary artery disease (CAD) in the urban population of India is similar to that in developed countries; Indian immigrants in industrialized countries have the highest prevalence of CAD. This is a cross-sectional survey within a random sample of a single urban setting in India. The relation between risk of CAD and plasma levels of vitamins A, C, E, and betacarotene was examined in 72 of 595 elderly subjects (12.1%) with CAD (aged 50 to 84 years). Plasma levels of vitamins A, C, E, and beta-carotene were significantly related to risk of CAD. Smoking (n = 145) and diabetes (n = 70) were the confounding factors. Lipid peroxides were higher in patients with CAD and diabetes, and in those who smoked. The inverse relation between CAD and low plasma vitamin C was substantially reduced after adjustment for smoking and diabetes. Vitamin A and E levels remained independently and inversely related to the risk of CAD after adjustment for age, smoking, diabetes, blood pressure, blood lipoproteins, and relative weight and body mass index. The adjusted odds ratios for CAD between the lowest and highest quintiles of vitamin E levels were 2.53 (95% confidence interval [CI] 1.11 to 5.31), vitamin C, 2.21 (95% CI 1.12 to 3.15), and beta-carotene, 1.72 (95% CI 0.88 to 3.62). The fatty acid composition of the diet, blood lipid levels, central obesity (waist-hip ratio),smoking habits, blood pressure, and plasma insulin levels do not appear to account for high rates of CAD among elderly Indians. The findings suggest that some elderly Indian populations with high rates of CAD can benefit from eating foods rich in antioxidant vitamins A, C, E, and beta-carotene. However, a reduction in vitamin levels may be due to changes in diet and lifestyle after diagnosis of CAD; therefore, more studies are necessary to confirm our findings.

Preoperative cardiac risk assessment for noncardiac surgery

Coronary artery disease (CAD) represents an important risk in patients undergoing elective noncardiac surgical procedures, in whom the stress of surgery and postoperative recovery can represent a significant ischemic burden. Population considerations: Preoperative cardiac assessment should be based on the prevalence of CAD (if known) in the population undergoing the procedure and the institutional event rate for the procedure. Procedures considered high-risk are vascular, intra-abdominal or thoracic, major orthopedic, and any emergency procedures. Individual considerations: Clinical history: A history of angina, congestive heart failure, diabetes mellitus, prior myocardial infarction, ventricular ectopy, and/or elderly (age > 70) are clinical parameters of increased risk. Functional capacity: Good functional capacity is the ability of a 50–70-year-old patient to achieve 6–8 METS of activity without significant symptoms of dyspnea on exertion. Further noninvasive testing: Preoperative testing may include routine treadmill exercise testing, ambulatory ECG monitoring, echocardiographic stress testing with dobutamine or exercise, and/or thallium perfusion imaging. Strategy for high risk patients: Assessing the severity of an abnormality (e.g., with thallium) results in a small percentage of positive test results yielding a high positive predictive value for events. Therefore, more aggressive interventions should be reserved for the most abnormal noninvasive test results, and the severity of the risk assessment should impact the timing of any coronary revascularization procedure, not the decision to proceed to more invasive testing and therapies. In summary, it is important to realize that most of the patients being screened, even vascular surgery patients (with high prevalence of CAD and procedural risk), will be found suitable to go to surgery without additional invasive intervention and cardiac revascularization. Thus good functional capacity and absence of cardiac risk factors should direct 30–40% of this population to elective surgery without further evaluation. The finding of high-risk perfusion scan abnormalities appears to be limited to 15–20% of those patients being recommended for further noninvasive testing. Coronary artery disease (CAD) represents an important risk in patients undergoing elective noncardiac surgical procedures, in whom the stress of surgery and postoperative recovery can represent a significant ischemic burden. Population considerations: Preoperative cardiac assessment should be based on the prevalence of CAD (if known) in the population undergoing the procedure and the institutional event rate for the procedure. Procedures considered high-risk are vascular, intra-abdominal or thoracic, major orthopedic, and any emergency procedures. Individual considerations: Clinical history: A history of angina, congestive heart failure, diabetes mellitus, prior myocardial infarction, ventricular ectopy, and/or elderly (age > 70) are clinical parameters of increased risk. Functional capacity: Good functional capacity is the ability of a 50–70-year-old patient to achieve 6–8 METS of activity without significant symptoms of dyspnea on exertion. Further noninvasive testing: Preoperative testing may include routine treadmill exercise testing, ambulatory ECG monitoring, echocardiographic stress testing with dobutamine or exercise, and/or thallium perfusion imaging. Strategy for high risk patients: Assessing the severity of an abnormality (e.g., with thallium) results in a small percentage of positive test results yielding a high positive predictive value for events. Therefore, more aggressive interventions should be reserved for the most abnormal noninvasive test results, and the severity of the risk assessment should impact the timing of any coronary revascularization procedure, not the decision to proceed to more invasive testing and therapies. In summary, it is important to realize that most of the patients being screened, even vascular surgery patients (with high prevalence of CAD and procedural risk), will be found suitable to go to surgery without additional invasive intervention and cardiac revascularization. Thus good functional capacity and absence of cardiac risk factors should direct 30–40% of this population to elective surgery without further evaluation. The finding of high-risk perfusion scan abnormalities appears to be limited to 15–20% of those patients being recommended for further noninvasive testing.

Preoperative cardiac risk assessment for noncardiac surgery

Coronary artery disease (CAD) represents an important risk in patients undergoing elective noncardiac surgical procedures, in whom the stress of surgery and postoperative recovery can represent a significant ischemic burden. Population considerations: Preoperative cardiac assessment should be based on the prevalence of CAD (if known) in the population undergoing the procedure and the institutional event rate for the procedure. Procedures considered high-risk are vascular, intra-abdominal or thoracic, major orthopedic, and any emergency procedures. Individual considerations: A history of angina, congestive heart failure, diabetes mellitus, prior myocardial infarction, ventricular ectopy, and/or elderly (age > 70) are clinical parameters of increased risk. Functional capacity: Good functional capacity is the ability of a 50-70-year-old patient to achieve 6-8 METS of activity without significant symptoms of dyspnea on exertion. Further noninvasive testing: Preoperative testing may include routine treadmill exercise testing, ambulatory ECG monitoring, echocardiographic stress testing with dobutamine or exercise, and/or thallium perfusion imaging. Strategy for high risk patients: Assessing the severity of an abnormality (e.g., with thallium) results in a small percentage of positive test results yielding a high positive predictive value for events. Therefore, more aggressive interventions should be reserved for the most abnormal noninvasive test results, and the severity of the risk assessment should impact the timing of any coronary revascularization procedure, not the decision to proceed to more invasive testing and therapies. In summary, it is important to realize that most of the patients being screened, even vascular surgery patients (with high prevalence of CAD and procedural risk), will be found suitable to go to surgery without additional invasive intervention and cardiac revascularization. Thus good functional capacity and absence of cardiac risk factors should direct 30-40% of this population to elective surgery without further evaluation. The finding of high-risk perfusion scan abnormalities appears to be limited to 15-20% of those patients being recommended for further noninvasive testing.

Single-photon emission tomography studies of rubidium-81 in the detection of ischaemic heart disease, using a stress-reinjection protocol

The present study was designed to determine the feasibility of using single-photon emission tomography (SPET) imaging with rubidium-81 (T1/2 = 4.54 h) to detect ischaemic heart disease, using a stress-reinjection protocol and a specially constructed 511-keV hexagonal hole collimator for a standard gamma camera. The diagnostic performance of 81Rb SPET in detecting coronary artery disease (CAD) was investigated in 52 patients with a high prevalence of CAD. Coronary arteriography was performed in 34 patients, 25 of whom were classified as having significant stenosis (> or = 50%). At peak exercise (Cornell protocol), 111-222 MBq 81Rb was injected i.v. for stress imaging, and after 3 h of rest, 74-111 MBq was reinjected for rest imaging. The displayed short- and long-axis slices and the polar map images were interpreted qualitatively. In comparison to coronary arteriography, which served as the gold standard, the performance of 81Rb SPET revealed a sensitivity of 95% for the detection of CAD. Images of diagnostic quality were obtained in all patients, these being comparable to thallium-201 SPET images. In conclusion, these results indicate that the described method can be routinely used for the positron emitter 81Rb with a conventional gamma camera and special shielding. 81Rb has the well-known advantages of a potassium analogue and 81Rb SPET permits better visualization, particularly of the posterior wall of the myocardium, due to the higher photon energy. Considering the typical dose of 201Tl used for SPET (74-148 MBq), a 81Rb SPET scan imposes a significantly lower radiation burden on the patient.

Coronary artery disease is highly prevalent among patients with premature peripheral vascular disease

This study was designed to document the prevalence of coronary artery disease (CAD) and associated cardiac complications among patients with symptoms of premature peripheral vascular disease. We studied the peripheral and coronary arterial circulations of 59 consecutive male military veterans diagnosed with premature peripheral vascular disease (age of onset < or = 45 years) affecting the lower extremity. Patients who had not previously undergone coronary angiography underwent exercise stress testing. Patients unable to perform exercise testing and those with abnormal exercise test results underwent coronary angiography. There was no evidence of CAD in 16 patients (29%) on the basis of normal exercise test results (n = 12) or normal coronary angiography results (n = 4). Forty-three patients (71%) had significant (> or = 50% lesion) CAD by coronary catheterization. Cardiac complications were frequent among the 43 patients. Eleven (65%) of the 17 patients with single-vessel CAD had previously documented myocardial infarctions, as did three (75%) of the four patients with two-vessel CAD and 18 (82%) of the 22 patients with three vessel or greater CAD. Three (18%) patients with one-vessel CAD had undergone coronary artery bypass grafting or percutaneous transluminal coronary angioplasty for symptoms, as had one patient (25%) with two-vessel CAD and 19 patients (86%) with three-vessel or greater CAD. Five patients died during the study period, four of myocardial infarction and one of stroke. Premature peripheral atherosclerosis is associated with a high prevalence of CAD. Detection of CAD is important in this group, because cardiac complications are frequent.

Diagnostic value of ambulatory Holter monitoring for the detection of coronary artery disease in patients with variable threshold angina pectoris

Patients with chronic stable angina pectoris may present with either fixed or variable threshold symptoms. To evaluate the diagnostic value of ambulatory Holter monitoring for the detection of coronary artery disease (CAD) in patients with variable threshold angina, 216 consecutive candidates for coronary angiography were investigated prospectively. For comparison, a group of 55 consecutive patients with fixed threshold angina was studied under the same conditions. Patients with prior myocardial infarction or angiographically documented CAD were excluded. Within 4 months of Holter monitoring, the advised coronary angiography was performed in 77% of the patients with variable threshold angina and in 89% of the patients with fixed threshold angina (p < 0.05). The prevalence of CAD was markedly lower in patients with variable threshold angina compared to patients with fixed threshold angina (54 vs 90%, p < 0.001). CAD patients of both subgroups, however, did not differ significantly with respect to the number of obstructed vessels, the Gensini coronary score, the number with impaired left ventricular function (ejection fraction < 50%) or the duration of ischemic episodes during Holter monitoring. Diagnostic accuracy of Holter monitoring did not differ between variable and fixed threshold angina groups (67 vs 78%). In 91% of the patients results obtained by Holter monitoring could be compared to the results of a bicycle stress test. In patients with fixed threshold angina the diagnostic accuracy was similar for both tests (80 vs 80%). In patients with variable threshold angina, the diagnostic accuracy of Holter monitoring exceeded that of the exercise stress test (68 vs 55%, p < 0.01). Thus, due to the high prevalence of CAD in these patients, information from both Holter monitoring and exercise electrocardiography is of limited value in patients with fixed threshold angina, despite the high diagnostic accuracy of the tests. In patients with variable threshold angina, however, a significantly lower prevalence of CAD enhances the diagnostic value of Holter monitoring, whereas the information from conventional exercise electrocardiography remains limited, due to a low sensitivity and a low specificity.

99mTc-2-Methoxy-lsobutyl-Isonitril in der Diagnostik der koronaren Herzkrankheit: Ergebnisse einer Multizenterstudie

A total of 226 patients was studied in a phase-Ill multicenter trial to compare the results of stress/rest 99mTc-MIBI with 201TI scintigraphy and/or coronary arteriography. The evaluation of planar and SPECT imaging was based on a semiquantitative visual scoring. A congruent diagnosis was generated from all planar 201TI and 99mTc-MIBI scintigrams performed in 36 patients. In 62 of 63 patients, SPECT-studies with 99mTc-MIBI and 201TI led to an identical diagnosis. In one patient a positive result was obtained with 201TI-SPECT whereas 99mTc-MIBI was negative. Segmental agreement for 1509 SPECT segments was 85.7%, for 554 planar segments it was 86.6%. In comparison to coronary arteriography, performed in 180 patients, the overall sensitivity for the correct diagnosis of coronary artery disease (CAD) was 86% for planar MIBI scintigraphy or 92% for MIBI-SPECT. Overall specificity was 100% for planar imaging and 57% for SPECT. The low specificity of MIBI-SPECT was probably due to high prevalence of CAD in this study population. In a subgroup of 43 patients, who underwent coronary angiography, identical results were found with 99mTc-MIBI and 201TI. Only one patient showed a positive scintigraphic result with both 99mTc-MIBI and 201TI without angiographically proven stenosis greater than 50% or prior myocardial infarction. Vessel sensitivities in stenosed coronary arteries (&gt;50% stenosis) were 54% for the LAD and 87% for the RCX/RCA areas with MIBI-SPECT, or 51 % or 79% for planar scintigraphy, respectively. Vessel specificities for SPECT were 65% in the U\D or 52% in the RCX/RCA, or 90% or 83% in planar imaging. According to the results of this study, 99mTc-MIBI is of the same diagnostic value as 201TI in nuclear cardiology. Scintigraphy with both radiopharmaceuticals correlates well with the diagnosis of CAD. Therefore, 99mTc-MIBI might be an effective substitute for 201TI for myocardial perfusion scintigraphy.

Predictive value of thallium scintigraphy in coronary artery disease.

To verify the predictive value of thallium exercise scintigraphy, 20 normal individuals and 60 patients with coronary artery disease (CAD) were examined, using a quantitative standard technique and receiver operating characteristic analysis. The sensitivity of thallium scintigraphy for the presence of CAD was 97% for patients with previous infarction and 85% for those without infarction. The sensitivity for the extent of CAD was 93% for vessels perfusing infarcted areas and only 67% for vessels without infarction. In patients without myocardial infarction, sensitivity for the number of diseased vessels decreased with increasing extent of CAD. An underestimation of hemodynamically significant stenoses was proven by a comparison with the results of exercise ventriculography. The predictive value of a normal scintigram at a high prevalence of CAD is as low as the predictive value of an abnormal scintigram at a low prevalence level (screening). Thallium scintigraphy is indicated in patients with a medium prevalence of CAD, e.g., in patients with atypical angina and in asymptomatic patients with pathologic ECG.