Hybrid imaging methods in the diagnosis of coronary artery disease

The aim of this study was to assess the accuracy of real-time myocardial contrast perfusion imaging (MCPI) during dobutamine stress in the diagnosis and localization of coronary artery disease (CAD) in patients with diabetes. Myocardial contrast echocardiography is a new technique that allows evaluation of myocardial perfusion. Its utility in diabetic patients has not been defined. Dobutamine-atropine stress test was performed in conjunction with MCPI using Optison or Definity at rest and at peak stress in 128 patients with diabetes and suspected CAD who underwent coronary angiography within 1 month. CAD was defined as > or =50% stenosis in one or more coronary artery. MCPI was considered diagnostic of CAD in the presence of reversible perfusion abnormalities. The normalcy rate of MCPI was additionally determined in 18 asymptomatic nondiabetic patients with low probability. CAD was detected in 101 (79%) patients by angiography. Reversible perfusion abnormalities were detected in 90 patients with and 13 patients without CAD. The overall sensitivity of MCPI was 89% (95% CI 83-95), specificity 52% (33-71), and accuracy 81% (75-88). Reversible abnormalities were detected in two or more vascular distributions in 44 of 56 patients with multivessel CAD and in 8 of 63 patients without (sensitivity 68%, specificity 87%, positive predictive value 84%, and accuracy 79%). Regional sensitivity was 75% (65-85) for left anterior descending CAD, 71% (60-83) for left circumflex, and 67% (55-78) for right CAD. MCPI was normal in 16 of the 18 patients with low clinical probability of CAD (normalcy rate 89%). MCPI is a useful noninvasive technique for the diagnosis and localization of CAD in diabetic patients. The extent of perfusion abnormalities can identify patients with multivessel CAD with a moderate sensitivity and high specificity.

ObjectivesCoronary computed tomography angiography (CCTA) has higher diagnostic accuracy than coronary artery calcium (CAC) score for detecting obstructive coronary artery disease (CAD) in patients with stable chest pain, while the added diagnostic value of combining CCTA with CAC is unknown. We investigated whether combining coronary CCTA with CAC score can improve the diagnosis of obstructive CAD compared with CCTA alone.MethodsA total of 2315 patients (858 women, 37%) aged 61.1 ± 10.2 from 29 original studies were included to build two CAD prediction models based on either CCTA alone or CCTA combined with the CAC score. CAD was defined as at least 50% coronary diameter stenosis on invasive coronary angiography. Models were built by using generalized linear mixed-effects models with a random intercept set for the original study. The two CAD prediction models were compared by the likelihood ratio test, while their diagnostic performance was compared using the area under the receiver-operating-characteristic curve (AUC). Net benefit (benefit of true positive versus harm of false positive) was assessed by decision curve analysis.ResultsCAD prevalence was 43.5% (1007/2315). Combining CCTA with CAC improved CAD diagnosis compared with CCTA alone (AUC: 87% [95% CI: 86 to 89%] vs. 80% [95% CI: 78 to 82%]; p < 0.001), likelihood ratio test 236.3, df: 1, p < 0.001, showing a higher net benefit across almost all threshold probabilities.ConclusionAdding the CAC score to CCTA findings in patients with stable chest pain improves the diagnostic performance in detecting CAD and the net benefit compared with CCTA alone.Clinical relevance statementCAC scoring CT performed before coronary CTA and included in the diagnostic model can improve obstructive CAD diagnosis, especially when CCTA is non-diagnostic.Key Points• The combination of coronary artery calcium with coronary computed tomography angiography showed significantly higher AUC (87%, 95% confidence interval [CI]: 86 to 89%) for diagnosis of coronary artery disease compared to coronary computed tomography angiography alone (80%, 95% CI: 78 to 82%, p < 0.001).• Diagnostic improvement was mostly seen in patients with non-diagnostic C.• The improvement in diagnostic performance and the net benefit was consistent across age groups, chest pain types, and genders.

Can apelins guide the diagnosis of coronary artery disease in COPD patients?

Thirty patients undergoing coronary cineangiography for diagnosis or evaluation of coronary artery disease had myocardial blood flow studies pre and post handgrip (isometric) exercise just prior to cineangiography. The handgrip was maintained at one-third maximum effort for three minutes. The patients also had treadmill exercise testing a day or two prior to the study. Treadmill testing was carried out until angina or positive ST-segment changes occurred or the patient attained 90% of predicted maximal heart rate. Of the 30 patients, seven had no coronary artery disease and 23 had significant disease, i.e., greater than 75% occlusion of at least one major coronary artery. Six of the 23 patients (26%) with disease had angina with handgrip and demonstrated a decreased myocardial blood flow, a significantly different response from the patients without agina (P less than 0.001). For the group without angina, the blood flow response was not significantly different from the normal group. Treadmill tests were positive in 19 of the 23 patients with coronary disease (83%). The arterial systolic and diastolic pressure rise was almost identical with the two stresses. The heart rate response, however, was significantly different (P less than 0.001), the rate increase being greater with treadmill exercise. The myocardial blood flow data demonstrate the relative insensitivity of handgrip exercise for the diagnosis of coronary artery disease. In terms of the supply demand ratio (diastolic pressure time/systolic pressure time) concept for subendocardial perfusion, it is possible that the difference between handgrip and treadmill stress may be due to the different heart rate response, more rapid heart rates having a relatively greater effect on diastolic than on systolic time indices, all other factors being equal.

Effective diagnosis and treatment of coronary artery disease (CAD) are key to the management of patients with diabetes. Although the use of specialized cardiac testing for CAD screening in asymptomatic patients varies widely and is the source of current controversy, evidence is emerging on the prevalence and predictors of asymptomatic ischemia in diabetic patients. Accurate diagnosis and risk stratification are essential in symptomatic patients with known or suspected CAD. Noninvasive cardiac testing has an important role in these patients, although evaluation for revascularization with cardiac catheterization is warranted in high-risk circumstances. This article reviews recent information that may help guide the clinician in the appropriate use of cardiac testing in diabetic patients.

Introduction: Heart disease remains the leading cause of death in the United States, with the disease burden particularly high in various racial and ethnic groups. In serving an underserved population comprised largely of Hispanic and African American individuals, it is crucial for an urban public hospital to diagnose heart disease in a resource-efficient and cost-effective manner. The greater positive predictive value of cardiac CT relative to exercise stress testing presents the opportunity for such hospitals to optimize resource utilization in identifying patients with coronary artery disease (CAD). Hypothesis: The positive predictive value of cardiac CT in diagnosing CAD is greater than that of exercise stress testing in the patient population served by an urban public hospital. Methods: Patients at Harbor-UCLA Medical Center (Torrance, California) were identified for inclusion in this observational study on the basis of a positive (i.e., abnormal) exercise stress test result or a positive cardiac CT result, during the period between January 2015 and September 2019. These patients were subsequently referred for invasive coronary artery angiography, with the diagnosis of obstructive CAD established by an indication for revascularization via percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). Data were analyzed using a two-tailed Z-test for two proportions. Results: Seventy-six catheterization laboratory results were analyzed. Fifteen subjects with an abnormal exercise stress test result, out of a total of 41 (36.6%), had an indication for PCI or CABG. Twenty-five cardiac CT imaging subjects, out of a total of 35 (71.4%), had an indication for PCI or CABG. The proportion of positive cardiac CT results with an indication for PCI or CABG was significantly higher than the abnormal exercise stress test proportion (p=0.0024). Conclusions: Among urban public hospital patients who were referred for invasive coronary artery angiography, it was determined that cardiac CT provides a greater positive predictive value in the diagnosis of obstructive CAD than exercise stress testing. This result may help guide the optimal allocation of diagnostic resources in an urban public hospital.

Analysis of multiple noninvasive tests offers the promise of more accurate diagnosis of coronary artery disease, but discordant test responses can occur frequently and, when observed, result in diagnostic uncertainty. Accordingly, 43 patients undergoing diagnostic coronary angiography were evaluated by noninvasive testing and the results subjected to analysis using Bayes' theorem of conditional probability. The procedures used included electrocardiographic stress testing for detection of exercise-induced ST segment depression, cardiokymographic stress testing for detection of exercise-induced precordial dyskinesis, myocardial perfusion scintigraphy for detection of exercise-induced relative regional hypoperfusion, and cardiac fluoroscopy for detection of coronary artery calcification. The probability for coronary artery disease was estimated by Bayes' theorem from each patient's age, sex, and symptom classification, and from the observed test responses. This analysis revealed a significant linear correlation between the predicted probability for coronary artery disease and the observed prevalence of angiographic disease over the entire range of probability from 0 to 100% (P less than 0.001 by linear regression). The 12 patients without angiographic disease had a mean posttest likelihood of only 7.0 +/- 2.6% despite the fact that 13 of the 60 historical and test responses were falsely "positive." In contrast, the mean posttest likelihood was 94.1 +/- 2.8% in the 31 patients with angiographic coronary artery disease, although 45 of the 155 historical and test responses were falsely "negative." In 8 of the 12 normal patients, the final posttest likelihood was under 10% and in 26 of the 31 coronary artery disease patients, it was over 90%. These estimates also correlated well with the pooled clinical judgment of five experienced cardiologists (P less than 0.001 by linear regression). The observed change in probability for disease for each of the 15 different test combinations correlated with their information content predicted according to Shannon's theorem (P less than 0.001 by linear regression). These results support the use of probability analysis in the clinical diagnosis of coronary artery disease and provide a formal basis for comparing the relative diagnostic effectiveness and cost-effectiveness of different test combinations.

Multislice CT angiography represents one of the most exciting technological revolutions in cardiac imaging and it has been increasingly used in the diagnosis of coronary artery disease. Rapid improvements in multislice CT scanners over the last decade have allowed this technique to become a potentially effective alternative to invasive coronary angiography in patients with suspected coronary artery disease. High diagnostic value has been achieved with multislice CT angiography with use of 64- and more slice CT scanners. In addition, multislice CT angiography shows accurate detection and analysis of coronary calcium, characterization of coronary plaques, as well as prediction of the disease progression and major cardiac events. Thus, patients can benefit from multislice CT angiography that provides a rapid and accurate diagnosis while avoiding unnecessary invasive coronary angiography procedures. The aim of this article is present an overview of the clinical applications of multislice CT angiography in coronary artery disease with a focus on the diagnostic accuracy of coronary artery disease; prognostic value of coronary artery disease with regard to the prediction of major cardiac events; detection and quantification of coronary calcium and characterization of coronary plaques. Limitations of multislice CT angiography in coronary artery disease are also briefly discussed, and future directions are highlighted.

Objective To compare low-dose dobutamine electrocardiography (ECG) stress test and echocardiography (ECHO) stress test in the diagnosis of coronary artery disease (CHD).Methods Fifty-six patients with CHD were chosen.They were given dobutamine before test in the speed of 1 μ g/(kg· min ),and gradually increased to 5 μ g/(kg·min).Low-dose dobutamine ECG stress test,ECHO stress test and coronary angiography (CAG) were performed,and the results were compared.The sensitivity,specificity and accuracy of low-dose dobutamine ECG stress test and ECHO stress test were calculated.Results CAG showed 37 cases of patients with coronary artery stenosis.The sensitivity,specificity and accuracy of low-dose dobutamine ECG stress test were 62.16％ (23/37),73.68％ (14/19) and 66.07％ (37/56).The sensitivity,specificity and accuracy of ECHO stress test were 86.49％ (32/37),52.63％ (10/19) and 75.00％ (42/56).There were significant differences in sensitivity and specificity between two test methods (P ＜0.05).Conclusions In the diagnosis of CHD, low-dose dobutamine ECG stress test has high specificity,and ECHO stress test has high sensitivity and accuracy.Combination of them has high clinical value. Key words: Dobutamine; Electrocardiography; Echocardiography; Coronary disease

The purpose of this study was to evaluate the diagnostic accuracy of сoronary сomputed tomography angiography (CCTA) in the diagnosis of stable coronary artery disease (CAD) in patients aged ≥70 years. The study included 390 patients aged ≥70 years with symptoms suggested stable CAD which underwent elective coronary artery angiography (CAG). Initially the prevalence of angiographically significant CAD was estimated according to the gender and chest pain character, and identifications of patients in whom CCTA was appropriate. After that diagnostic accuracy and сost-efficiency of CCTA in the diagnosis of stable CAD in 82 patients with atypical angina and non-anginal chest pain were evaluated. The prevalence of obstructive CAD in patients with typical angina was very high and they were excluded from the final analysis. Among 82 patients with atypical angina and non-anginal pain which underwent CCTA 48 (59%) patients had obstructive CAD. CСTA data matched with results of CAG in all cases. Among 34 patients that had non-obstructive CAD the results of CCTA and CAG matched in 88% cases. CCTA has sensitivity, specificity, positive predictive value, negative predictive value of 100%, 88%, 92% and 100% respectively. The likelihood ratio for positive result was 8.3, likelihood ratio for negative result was 0.3. Positive result increased post-test probabilityof obstructive CAD from 42% to 86%, negative result reduced post-test probabilityof obstructive CAD to 0%. negative CCTA result in patients aged 70 years and older with atypical angina and non-anginal pain allows to exclude the presence of obstructive CAD. The likelihood ratio for positive result indicates a moderately difference between the pre-test and post-test probability of the presence of obstructive CAD. In patients aged ≥70 years with atypical angina or non-anginal chest pain which have inconclusive results of functional testing or unable undergo functional testing CCTA allows to increase diagnostic yield of CAG and reduce the frequency of minor complications and diagnostic evaluation costs.

The introduction of highly active antiretroviral therapy (HAART) has increased human immunodeficiency virus (HIV) patient longevity by 10-15 years. This increased longevity has habituated new cardiovascular complications, in particular, accelerated coronary artery disease (CAD). Although dobutamine stress echocardiography (DSE) is a highly sensitive and specific test for the noninvasive detection of underlying CAD in the general population, its utility in the HIV population remains unknown. The objective of the current study was to assess the validity of DSE for the noninvasive detection of underlying symptomatic CAD in the HIV population using cardiac catheterization as the gold standard. A total of 40 HIV positive patients (mean 49 ± 8 years; 31 males) between 2006 and 2009 inclusively underwent routine DSE and coronary angiography. A positive stress echo with new wall motion abnormalities was detected in 9 (23%) individuals. Coronary angiography, following DSE, detected obstructive CAD in 12 (30%) individuals. For the diagnosis of obstructive CAD, DSE has a sensitivity of 67%, specificity of 97%, positive predictive value (PPV) of 89%, and negative predictive value (NPV) of 87%. In this select HIV population, DSE was highly specific for the noninvasive detection of obstructive CAD.

The cardiointegram: Detection of coronary artery disease in males with chest pain and a normal resting electrocardiogram

The early diagnosis of coronary artery disease (CAD) enables early intervention for the modifiable risk factors of the disease. Coronary artery calcification (CAC) detected incidentally on standard noncontrast chest computed tomography (CT) provides an opportunity for the early diagnosis of CAD. The purpose of this study was to demonstrate that CAC should be routinely reported when evaluating thoracic CT examinations. Routine reporting of CAC will contribute to the early diagnosis of CAD. The present study included 279 patients who underwent conventional coronary angiography (CAG) and CT within one month before undergoing CAG. The CAG and CT images of the patients were evaluated retrospectively. The levels of coronary artery stenosis were determined in reference to the CAG images. The CAC scores of the patients were calculated using the Weston method based on their chest CT images. The mean age of the patients was 63.2 ± 11.5 (range, 41-93) years, and 172 (61.6%) of them were men. The Weston score (WS) was 0 in 18.9% of the patients with obstructive CAD (OCAD), whereas it was ≥ 7 in 27.9% of patients. All patients with a WS of ≥ 7 had OCAD. All patients without luminal stenosis or < 50% stenosis had a WS of < 7. The CAC score is useful for the diagnosis of CAD and OCAD. If CAC is identified on standard noncontrast chest CT, it should be scored and reported accordingly. The WS can be used for CAC scoring.

Not all patients with angina pectoris have coronary artery stenosis. To facilitate the diagnosis of coronary artery disease (CAD), we sought to identify predictive factors of pulse spectrum analysis, which was developed by Wang and is one technique of modern pulse diagnosis. The patients suffered from chest pain and received cardiac catheterization to confirm the CAD diagnosis and Gensini score were recruited. Their pulse waves of radial artery were recorded. Then, by performing a fast Fourier transform, 10 amplitude values of frequency spectrum harmonics were obtained. Each harmonic amplitude was divided by the sum of all harmonic amplitude values, obtaining the relative percentages of 10 harmonics (C1-C10). Subsequently, multivariate logistic regression was conducted with two models and the areas under the receiver operating characteristic curves (ROC) of these 2 models were compared to see if combining the pulse diagnosis parameters with the risk factor of CAD can increase the prediction rate of CAD diagnosis. The predictive factors of CAD severity were analyzed by multivariate linear regression. A total of 83 participants were included; 63 were diagnosed CAD and 20 without CAD. In the CAD group, C1 was greater and C5 was lower than those of the non-CAD group. The CAD risk factors were put alone in Model 1 to perform the multivariate logistic regression analysis which had a prediction rate of 77.1%; while putting the C1 and C5 harmonics together with the risk factors into Model 2, the prediction rate increased to 80.7%. Finally, the area under ROC of Model 1 and Model 2 was 0.788 and 0.856, respectively. Furthermore, left C1, left C5, gender, and presence of hyperlipidemia were predictors of CAD severity. Therefore, pulse spectrum analysis may be a tool to facilitate CAD diagnosis before receiving cardiac catheterization. The harmonics C1 and C5 were favorable predictive indicators.

Aims This systematic literature review (SLR) consolidated economic and healthcare resource utilization (HCRU) evidence for positron emission tomography (PET) and single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) to inform future economic evaluations. Materials and methods An electronic search was conducted in MEDLINE, Embase, and Cochrane databases from 2012–2022. Economic and HCRU studies in adults who underwent PET- or SPECT-MPI for coronary artery disease (CAD) diagnosis were eligible. A qualitative methodological assessment of existing economic evaluations, HCRU, and downstream cardiac outcomes was completed. Exploratory meta-analyses of clinical outcomes were performed. Results The search yielded 13,439 results, with 71 records included. Economic evaluations and comparative clinical trials were limited in number and outcome types (HCRU, downstream cardiac outcomes, and diagnostic performance) assessed. No studies included all outcome types and only one economic evaluation linked diagnostic performance to HCRU. The meta-analyses of comparative studies demonstrated significantly higher rates of early- and late-invasive coronary angiography and revascularization for PET- compared to SPECT-MPI; however, the rate of repeat testing was lower with PET-MPI. The rate of acute myocardial infarction was lower, albeit non-significant with PET- vs. SPECT-MPI. Limitations and conclusions This SLR identified economic and HCRU evaluations following PET- and SPECT-MPI for CAD diagnosis and determined that existing studies do not capture all pertinent outcome parameters or link diagnostic performance to downstream HCRU and cardiac outcomes, thus, resulting in simplified assessments of CAD burden. A limitation of this work relates to heterogeneity in study designs, patient populations, and follow-up times of existing studies. Resultingly, it was challenging to pool data in meta-analyses. Overall, this work provides a foundation for the development of comprehensive economic models for PET- and SPECT-MPI in CAD diagnosis, which should link diagnostic outcomes to HCRU and downstream cardiac events to capture the full CAD scope.