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Context: Cardiogoniometry (CGM) is a noninvasive technique for quantitative three-dimensional vectorial analysis of myocardial depolarization and repolarization. We describe a method of surface electrophysiological cardiac assessment using CGM performed at rest to detect variables helpful in identifying coronary artery disease (CAD) and interplaying factors in patients who underwent coronary artery bypass graft (CABG). Materials and Methods: In this study, all patients with CAD undergoing CABG were enrolled. Echocardiography, CGM, and electrocardiography (ECG) were obtained before surgery and a month later. The ECG and CGM alterations were compared before and after CABG and the accuracy of those two methods was evaluated. Results: In this study, 50 patients were enrolled, of which 33 (66%) were male versus 17 (44%) female, with a mean age of 39.12 ± 60 years. The mean ejection fraction before and after surgery was 44.3 ± 7.9% (range: 20–55) and 40.9 ± 12.5% (20–50), respectively. Before surgery, all patients had sinus rhythm, five cases had left bundle-branch block (LBBB), and one case was with right bundle-branch block (RBBB). Subsequently, after surgery, five cases had LBBB, and two cases were found to have RBBB. The rate of postoperation bleeding was 20%. There was no significant change in echocardiographic characteristics before and after operation (P = 0.81); likewise, no significant change was seen in ECG criteria before and after operation (P = 0.96). A significant correlation was seen regarding CGM characteristics before and after CABG (P = 0.003). Conclusions: A significant association was seen regarding CGM characteristics before and after undergoing an operation. In addition, the specificity and sensitivity of the CGM and ECG before and after operation improved well.

Abstract Background Exercise electrocardiography (ECG) is a noninvasive test aiming at producing ischemic changes. However, resting ECG cannot be adopted in diagnosing myocardial ischemia till ST-segment depressions. Therefore, this study aimed to detect myocardial energy defects in resting ECG using the Hilbert–Huang transformation (HHT) in patients with angina pectoris. Methods Electrocardiographic recordings of positive exercise ECG by performing coronary imaging test (n = 26) and negative exercise ECG (n = 47) were collected. Based on the coronary stenoses severity, patients were divided into three categories: normal,

Aims: There is a paucity of randomized diagnostic studies in women with suspected coronary artery disease (CAD). This study sought to assess the relative value of exercise stress echocardiography (ESE) compared with exercise electrocardiography (Ex-ECG) in women with CAD. Methods and results: Accordingly, 416 women with no prior CAD and intermediate probability of CAD (mean pre-test probability 41%), were randomized to undergo either Ex-ECG or ESE. The primary endpoints were the positive predictive value (PPV) for the detection of significant CAD and downstream resource utilization. The PPV of ESE and Ex-ECG were 33% and 30% (P = 0.87), respectively for the detection of CAD. There were similar clinic visits (36 vs. 29, P = 0.44) and emergency visits with chest pain (28 vs. 25, P = 0.55) in the Ex-ECG and ESE arms, respectively. At 2.9 years, cardiac events were 6 Ex-ECG vs. 3 ESE, P = 0.31. Although initial diagnosis costs were higher for ESE, more women underwent further CAD testing in the Ex-ECG arm compared to the ESE arm (37 vs. 17, P = 0.003). Overall, there was higher downstream resource utilization (hospital attendances and investigations) in the Ex-ECG arm (P = 0.002). Using National Health Service tariffs 2020/21 (British pounds) the cumulative diagnostic costs were 7.4% lower for Ex-ECG compared with ESE, but this finding is sensitive to the cost differential between ESE and Ex-ECG. Conclusion: In intermediate-risk women who are able to exercise, Ex-ECG had similar efficacy to an ESE strategy, with higher resource utilization whilst providing cost savings. Central illustration Randomized controlled trial comparing diagnostic accuracy, efficacy, resource utilization, and costs based on an initial exercise echocardiography strategy vs. an exercise electrocardiography strategy in women with suspected angina. [ABSTRACT FROM AUTHOR]

Background: Exercise electrocardiography (ECG) is a noninvasive test aiming at producing ischemic changes. However, resting ECG cannot be adopted in diagnosing myocardial ischemia till ST-segment depressions. Therefore, this study aimed to detect myocardial energy defects in resting ECG using the Hilbert–Huang transformation (HHT) in patients with angina pectoris. Methods: Electrocardiographic recordings of positive exercise ECG by performing coronary imaging test (n = 26) and negative exercise ECG (n = 47) were collected. Based on the coronary stenoses severity, patients were divided into three categories: normal, < 50%, and ≥ 50%. During the resting phase of the exercise ECG, all 10-s ECG signals are decomposed by HHT. The RT intensity index, composed of the power spectral density of the P, QRS, and T components, is used to estimate the myocardial energy defect. Results: After analyzing the resting ECG using HHT, the RT intensity index was significantly higher in patients with positive exercise ECG (27.96%) than in those with negative exercise ECG (22.30%) (p < 0.001). In patients with positive exercise ECG, the RT intensity index was gradually increasing with the severity of coronary stenoses: 25.25% (normal, n = 4), 27.14% (stenoses < 50%, n = 14), and 30.75% (stenoses ≥ 50%, n = 8). The RT intensity index of different coronary stenoses was significantly higher in patients with negative exercise ECG, except for the normal coronary imaging test. Conclusions: Patients with coronary stenoses had a higher RT index at the resting stage of exercise ECG. Resting ECG analyzed using HHT could be a method for the early detection of myocardial ischemia. [ABSTRACT FROM AUTHOR]

BackgroundThe utility of exercise-induced ST-segment depression for diagnosing ischemic heart disease (IHD) in women is unclear.HypothesisBased on evidence that IHD pathophysiology in women involves coronary vascular dysfunction, we hypothesized that coronary vascular dysfunction contributes to exercise electrocardiography (Ex-ECG) ST-depression in the absence of obstructive coronary artery disease, so-called false positive results. We tested our hypothesis in a pilot study evaluating the relationship between peripheral vascular endothelial function and Ex-ECG.MethodsTwenty-nine asymptomatic women without cardiac risk factors underwent maximal Bruce protocol exercise treadmill testing and peripheral endothelial function assessment using peripheral arterial tonometry (Itamar EndoPAT 2000) to measure reactive hyperemia index (RHI). The relationship between RHI and Ex-ECG ST-segment depression was evaluated using logistic regression and differences in subgroups using 2-tailed t tests.ResultsMean age was 54 ± 7 years, body mass index 25 ± 4 kg/m2 , and RHI 2.51 ± 0.66. Three women (10%) had RHI 0.05). RHI did not predict ST-segment depression.ConclusionsOur pilot study demonstrates high prevalence of exercise-induced ST-segment depression in asymptomatic, middle-aged, overweight women. Peripheral vascular endothelial dysfunction did not predict Ex-ECG ST-segment depression. Further work is needed to investigate the utility of vascular endothelial testing and Ex-ECG for IHD diagnostic and management purposes in women.

Exercise electrocardiography (EET) is a safe and cost-effective method to predict the presence, prognosis, and severity of coronary artery disease (CAD). Various score models have been developed to increase predictive power of EET. In this study, we aimed to evaluate whether adding ST depression duration could have an effect on increasing the value of Duke treadmill score (DTS) in predicting obstructive CAD. In this single centred, cross-sectional study, we evaluated a total of 258 patients who presented with a complaint of chest pain and undergone coronary angiogram in result of a positive EET. DTS was calculated for all the patients. The new score-revised DTS- was calculated by adding total ST depression time to classical DS parameters. We compared area under the curve (AUC) of DTS and revised DTS by Delongi method. Mean age of the group was 58.43 ± 9.37, and 37.2% (n = 96) were female. Mean total ST-depression duration was 171.72 ± 91.43 msec in normal artery group,241.54 ± 118.11 msec in non-obstructive CAD group, and 281.26 ± 113.64 in obstructive CAD group.ST-depression duration in both exercise and recovery, and total ST depression duration were significantly higher in obstructive CAD group than non-obstructive and normal artery groups (p = 0.024, p = 0.01, p < 0.01, and p < 0.01, respectively). Revised DTS had significantly higher predictive value of obstructive CAD compared to classical DS (AUC (95%CI): 0.744 vs. 0.626, p < 0.001). The AUC of DS was significantly lower than the new score (z-score:3.274, p = 0.011). In conclusion, adding ST depression duration to DTS calculation is increasing the discriminative value of DTS to predict obstructive CAD. Benefits of EET within the context of the management of CAD is well-known, hence, it is clear that physicians may use revised DTS. [ABSTRACT FROM AUTHOR]

Introduction: To reduce contacts during the COVID-19 pandemic, we elaborated a protocol for ambulatory referrals for exercise testing that included discharges from the stress test laboratory (STL). Methods and Results: From 403 patients referred for chest pain (68%) or dyspnea (32%), 219 were straight discharged from the STL (54%), without findings of coronary artery disease in 192 (88%), whereas in 120 (29.5%), further visits were recommended. Medical treatment was modified after the tests in 116 patients (29%). Conclusions: A strategy consisting of discharge from the STL for patients with negative/spurious stress test results, making therapeutic recommendations, seems feasible, effective, and overall opportune in the current situation.

Myocardial ischemia (MI) has the highest mortality rate in the world. Traditional noninvasive MI examinations include exercise electrocardiography tests (EETs) and stress echocardiography (SE). Treadmill and dobutamine tests are commonly used as stress protocols. In the present study, 278 patients with suspected MI were examined, 66 of whom were diagnosed with MI and 212 did not show evidence of MI by coronary angiography (CAG)/coronary CT angiography (CCTA). All patients underwent clinical EET and SE evaluations prior to CAG/CCTA. All groups were compared based on specific clinical parameters including age, sex, blood pressure, heart rate, blood oxygen saturation, underlying conditions and ejection fraction/fraction shortening. The data indicated superior diagnostic efficiency of the combined EET+SE method for the diagnosis of suspected MI compared with either EET or SE alone. The sensitivity/specificity/positive predictive value and negative predictive value for detecting MI were excellent compared with those of traditional examinations. The diagnostic efficiency of the combination analysis may reduce the prevalence of MI and medical costs. The present study provided novel insight for the development of methods that may be used for MI detection and prediction. [ABSTRACT FROM AUTHOR]

Background: Type 2 diabetes mellitus (DM) is an established risk factor for cardiovascular events and the development of congestive heart failure (HF). Diastolic dysfunction is considered a precursor of HF and may be diagnosed noninvasively by echocardiography. Diastolic dysfunction is common in well-controlled type 2 diabetic patients without clinically detectable heart disease. Left ventricular diastolic dysfunction represents the earliest preclinical dysfunction and that it can progress to asymptomatic HF. Aim of the Work: The aim of the study is to evaluate if diastolic dysfunction in diabetic patients is due to silent ischemia. Methods: This study included 80 asymptomatic patients with type 2 DM. Echocardiography was done to all patients to assess systolic and diastolic functions. Exercise electrocardiogram (ECG) was done for all patients to detect ischemic heart disease. Coronary angiography was done to patients with positive exercise ECG test. Results: The incidence of diastolic dysfunction was 75%; among the studied groups. Impaired relaxation was detected in 87% and pseudo normal pattern was detected in 13% of subjects with diastolic dysfunction. Patients with normal diastolic function had negative stress exercise test, while those with diastolic dysfunction, 12 patients had positive exercise stress ECG (40%) and 18 patients had negative exercise stress ECG (60%). Conclusion: These findings indicate that coronary artery disease is not uncommon in diabetic patients with diastolic dysfunction and increase markedly in patients with positive stress exercise electrocardiography. [ABSTRACT FROM AUTHOR]

Introduction: Exercise electrocardiography (EET) is frequently used in coronary artery disease, but the specificity of this test is very low. In the literature, parameters such as QT prolongation and QT dispersion which show coronary artery disease and arrhythmia were not sufficiently investigated using EET. The aim of this study was to investigate whether QT interval prolongation or dispersion (QT disp) in a positive EET test could predict critical coronary artery disease (CAD). Material and methods: Patients with a positive exercise test were included in the study. Data regarding QT, QTc (corrected QT interval) and QT disp values before, during and after EET were noted. Critical coronary artery occlusions (= 70%) was recorded from coronary angiographic images. Patients were divided into two groups (critical CAD and non-critical CAD). Results: A total of 192 patients were found to be eligible for the study. There were 126 patients in the non-critical CAD group (group 1) and 66 patients in the critical CAD group (group 2). Recovery QTc, peak QT disp, and recovery QT disp were significantly increased in group 2 (p < 0.001 for each). Also, target heart rate (p = 0.012), basal systolic blood pressure (p = 0.005) and diastolic blood pressure (p < 0.001) were significantly higher in group 1. Recovery QTc (OR = 1.051) and recovery QT disp (OR = 1.117) were determined as the independent predictors for critical CAD. The ROC analysis results indicated that critical CAD could be diagnosed with 90% sensitivity when the recovery QTc cut-off value was set as 404 ms. Conclusions: In patients with positive EET, prolonged QTc and QT disp values measured during the recovery period would predict critical CAD. Thus, the clinical accuracy of EET may be enhanced. [ABSTRACT FROM AUTHOR]

Objectives: We hypothesised that stress echocardiography (SE), may be superior to exercise ECG (ExECG), for predicting CAD and outcome, and cost-beneficial, when performed as initial investigation in newly suspected angina. Methods: All patients seen in 2011, with suspected angina, no history of CAD, pre-test likelihood of CAD of >10% and who underwent SE or ExECG as first line were identified retrospectively. Cost to diagnosis was calculated by adding the cost of all tests, up to and including coronary angiography (CA), on an intention-to-treat basis. Follow-up data on cardiac death and myocardial infarction (MI) were collected, 26 months after the presentation of the last study patient. Results: A total of 456 patients underwent ExECG (224 (49%) negative, 93 (20%) positive, 139 (31%) inconclusive) and 241 underwent SE (200 (83%) negative, 35 (15%) positive, 6 (2%) inconclusive) as first line. In patients subsequently undergoing CA, CAD was present in 46% (37/80) of patients with positive ExECG vs. 72% (23/32) patients with positive SE (p = 0.01). Mean cost to diagnosis was £456 for the ExECG vs. £360 for the SE group (p = 0.002). Over a mean follow-up period of 31 ± 5 months, cardiac events were 2% each in negative SE vs. negative ExECG (p = 0.9). Conclusions: SE is superior to ExECG for prediction of CAD and is cost-beneficial when used as initial test in patients with no history of CAD presenting with suspected angina.

Aims Exercise electrocardiography (ExECG) is widely used in suspected stable angina (SA) as the initial test for the evaluation of coronary artery disease (CAD). We hypothesized that exercise stress echo (ESE) would be efficacious with cost advantage over ExECG when utilized as the initial test. Methods and results Consecutive patients with suspected SA, without known CAD were randomized into ExECG or ESE. Patients with positive tests were offered coronary angiography (CA) and with inconclusive tests were referred for further investigations. All patients were followed-up for cardiac events (death, myocardial infarction, and unplanned revascularization). Cost to diagnosis of CAD was calculated by adding the cost of all investigations, up to and including CA. In the 194 and 191 patients in the ExECG vs. ESE groups, respectively, pre-test probability of CAD was similar (34 ± 23 vs. 35 ± 25%, P = 0.6). Results of ExECG were: 108 (55.7%) negative, 14 (7.2%) positive, 72 (37.1%) inconclusive and of ESE were 181 (94.8%) negative, 9 (4.7%) positive, 1 (0.5%) inconclusive, respectively. Patients with obstructive CAD following positive ESE vs. Ex ECG were 9/9 vs. 9/14, respectively (P = 0.04). Cost to diagnosis of CAD was £266 for ESE vs. £327 for ExECG (P = 0.005). Over a mean follow-up period of 21 ± 5 months, event rates were similar between the two groups. Conclusion In this first randomized study, ESE was more efficacious and demonstrated superior cost-saving, compared with ExECG when used as the initial investigation for the evaluation of CAD in patients with new-onset suspected SA without known CAD. [ABSTRACT FROM AUTHOR]

Asli Tanindi1 Hilal Olgun1 Ayse Tuncel2 Bulent Celik3 Hatice Pasaoglu2 Bulent Boyaci11Department of Cardiology, 2Department of Medical Biochemistry, Faculty of Medicine, 3Department of Statistics, Faculty of Health Sciences, Gazi University, Ankara, TurkeyObjectives: An impaired heart rate response during exercise (chronotropic incompetence) and an impaired heart rate recovery (HRR) after exercise are predictors of cardiovascular risk and mortality. Cystatin C is a novel marker for cardiovascular disease. We aimed to investigate exercise electrocardiographic responses in patients with metabolic syndrome who were without overt diabetes mellitus, in addition to the association of serum cystatin C levels with the exercise electrocardiographic test results.Method: Forty-three consecutive patients admitted to a cardiology outpatient clinic without angina pectoris were recruited if they met criteria for metabolic syndrome but did not have overt diabetes mellitus. Serum cystatin C levels were measured, and all participants underwent exercise electrocardiographic testing. Patients who were found to have ischemia had a coronary angiography procedure.Results: The mean cystatin C level of patients was higher in metabolic syndrome group than healthy controls (610.1 ± 334.02 vs 337.3 ± 111.01 µg/L; P < 0.001). The percentage of patients with ischemia confirmed by coronary angiography was 13.9% in the metabolic syndrome group. Cystatin C levels in the ischemic patients of the metabolic syndrome group were higher than that in nonischemic patients (957.00 ± 375.6 vs 553.8 ± 295.3 µg /L; P = 0.005). Chronotropic incompetence was observed in 30.2% of the patients with metabolic syndrome compared with 16.7% in the control group (P = 0.186). Chronotropic response indices were 0.8 ± 0.18 versus 0.9 ± 0.10 for the two groups, respectively (P = 0.259). HRR was significantly lower in the metabolic syndrome patients compared with the controls (20.1 ± 8.01 vs 25.2 ± 4.5 per min; P , 0.001), and the ST-segment adjustment relative to heart rate(ST/HR index ratio) was 1.4 ± 1.34 versus 0.4 ± 0.31 µV/beat (P < 0.001), respectively. Cystatin C was negatively correlated with the chronotropic response index (CRI) and HRR and was positively correlated with ST/HR index in the entire study population (R = -0.658, -0.346, 0.388, respectively; P < 0.05).Conclusions: A substantial proportion of metabolic syndrome patients without overt diabetes mellitus had silent coronary ischemia in addition to impairment of objective exercise electrocardiographic parameters. In the metabolic syndrome patients without overt diabetes mellitus, cystatin C levels were found to be elevated and the elevation was more pronounced in the subgroup with silent ischemia. Cystatin C was also correlated with HRR and CRI.Keywords: exercise electrocardiography, metabolic syndrome, silent ischemia, cystatin C

The goals of this study were to determine the prevalence and determinants of false-positive exercise tests in athletes. Data from all athletes who visited the Department of Sport Medicine for assessment of sports eligibility during a 1.5-year period were reviewed retrospectively. Potential determinants of (false) positive test results that were evaluated included demographics, cardiovascular risk factors, sports characteristics, resting electrocardiogram ( ECG) abnormalities, and exercise capacity. Data from 1298 athletes were included. In 53 athletes (4.1%), the exercise ECG was classified as positive. Among 38 athletes who were referred to a sports cardiologist for further diagnostic evaluation, 36 (95%) were classified as having a false-positive test result and 2 athletes (5%) required coronary revascularization. Athletes with a false-positive test were older than athletes with a negative test (53 ± 8 vs 45 ± 13 years, P = 0.03). In conclusion, exercise electrocardiography has a low positive predictive value in asymptomatic recreational and competitive athletes, with a false-positive test result being associated with higher age. Given the relatively high prevalence of false-positive test results in this population, efforts should be made to develop strategies aimed at identifying false-positive test results in a simple noninvasive manner. [ABSTRACT FROM AUTHOR]

BACKGROUND: To explore the prognostic performance of coronary computed tomography angiography (CCTA) and exercise electrocardiography (XECG) in asymptomatic subjects. METHODS: We retrospectively enrolled 812 (59 ± 9 years, 60.8% male) asymptomatic subjects who underwent CCTA and XECG concurrently from 2003 through 2009- Subjects were followed-up for major adverse cardiac events (MACE) including cardiac death, nonfatal myocardial infarction, unstable angina, and revascularization after 90 days from index CCTA. RESULTS: The prevalence of occult coronary artery disease (CAD) detected by CCTA was 17.5% and 120 subjects (14.8%) had positive XECG. During a mean follow-up of 37 ± 16 months, nine subjects experienced MACE. In multivariable Cox-regression analysis, only the presence of CAD by CCTA independently predicted future MACE (p = 0.002). Moreover, CAD by CCTA improved the predictive value when added to a clinical risk factor model using the likelihood ratio test (p < 0.001). Notably, the prognostic value of CCTA persisted in the moderate-to-high-risk group as classified by the Duke treadmill score (p = 0.040), but not in the low-risk group (p = 0.991). CONCLUSION: CCTA provides incremental prognostic benefit over and above XECG in an asymptomatic population, especially for those in a moderate-to-high-risk group as classified by the Duke treadmill score. Risk stratification using XECG may prove valuable for identifying asymptomatic subjects who can benefit from CCTA. [ABSTRACT FROM AUTHOR]

Background A recent pilot study suggested that exercise-induced myocardial ischaemia may lead to a delayed release of cardiac biomarkers, so that later sampling, for example, at 4 h after exercise could be used for diagnostic purpose. Materials and methods In an observational study, we enrolled 129 consecutive patients referred for evaluation of a suspected coronary artery disease by rest/stress myocardial perfusion single-photon emission computed tomography. The treating cardiologist used all available clinical information to quantify clinical judgment regarding the presence of myocardial ischaemia using a visual analogue scale twice: prior and after stress testing. BNP levels were determined in a blinded fashion at rest, at peak stress and 4 h after peak stress. The presence of myocardial ischaemia was adjudicated based on perfusion single-photon emission computed tomography and coronary angiography findings by an independent cardiologist. Results Myocardial ischaemia was detected in 58 patients (45%). Patients with myocardial ischaemia had significantly higher BNP levels at all times, compared to patients without ischaemia: BNP rest (99 vs. 61 pg/mL P = 0·007), BNP stress (125 vs. 77 pg/mL P = 0·02) and BNP 4 h (114 vs. 71 pg/mL P = 0·018). Diagnostic accuracy as quantified by the area under the receiver operating characteristics curve ( AUC) was moderate for all time points ( AUC 0·64-0·66). The change in BNP between rest and 4 h did not provide added value, neither to the baseline BNP level nor to clinical judgment. Conclusion In contrast to our hypothesis, myocardial ischaemia did not lead to a differential delayed release of BNP. Late sampling did not seem clinically useful. [ABSTRACT FROM AUTHOR]

Background Limited data are available on the added value of exercise echocardiography (ExEcho) over exercise electrocardiography (ExECG) in patients with suspected acute coronary syndromes (ACS) referred to a chest pain unit. We aimed to assess the incremental value of ExEcho over ExECG in this setting. Methods ExECG and ExEcho were performed in parallel in 1052 patients with suspected ACS, nondiagnostic but interpretable electrocardiograms, and negative serial troponin results. The primary outcome was a composite of coronary death, nonfatal myocardial infarction or unstable angina with angiographic documentation of significant coronary artery disease within 6 months. Results The primary outcome occurred in 2/614 patients (0.3%) with both negative ExECG and ExEcho, 3/60 (5%) with positive ExECG and negative ExEcho, 73/135 (54.1%) with negative ExECG and positive ExEcho, 106/136 (77.9%) with both positive ExECG and ExEcho, and 8/107 (7.5%) with inconclusive results. The addition of ExEcho data to a model based on clinical and ExECG data significantly increased the c statistic from 0.898 to 0.968 (change + 0.070, 95% confidence interval 0.052–0.092), with a continuous net reclassification improvement of 1.56 and an integrated discrimination improvement of 22% ( p < 0.001). Decision curve analysis showed that a strategy of referral to coronary angiography based on ExEcho was associated with the highest net benefit and with the largest reduction in unnecessary coronary angiographies. Conclusion ExEcho provides significant incremental prognostic information and higher net clinical benefit than a strategy based on ExECG in patients referred to a chest pain unit for suspected ACS and negative troponin levels. [ABSTRACT FROM AUTHOR]

Background: Current practice for suspected acute coronary syndrome (ACS) involves troponin testing 10–12 hours after symptom onset to diagnose myocardial infarction (MI). Patients with a negative troponin can be investigated further with computed tomographic coronary angiography (CTCA) or exercise electrocardiography (ECG). Objectives: We aimed to estimate the diagnostic accuracy of early biomarkers for MI, the prognostic accuracy of biomarkers for major adverse cardiac adverse events (MACEs) in troponin-negative patients, the diagnostic accuracy of CTCA and exercise ECG for coronary artery disease (CAD) and the prognostic accuracy of CTCA and exercise ECG for MACEs in patients with suspected ACS. We then aimed to estimate the cost-effectiveness of using alternative biomarker strategies to diagnose MI, and using biomarkers, CTCA and exercise ECG to risk-stratify troponin-negative patients. Data sources: We searched MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations; Cumulative Index of Nursing and Allied Health Literature (CINAHL), EMBASE, Web of Science, Cochrane Central Database of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews (CDSR), NHS Database of Abstracts of Reviews of Effects (DARE) and the Health Technology Assessment database from 1985 (CTCA review) or 1995 (biomarkers review) to November 2010, reviewed citation lists and contacted experts to identify relevant studies. Review methods: Diagnostic studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool and prognostic studies using a framework adapted for the project. Meta-analysis was conducted using Bayesian Markov chain Monte Carlo simulation. We developed a decision-analysis model to evaluate the cost-effectiveness of alternative biomarker strategies to diagnose MI, and the cost-effectiveness of biomarkers, CTCA or exercise ECG to risk-stratify patients with a negative troponin. Strategies were applied to a theoretical cohort of patients with suspected ACS. Cost-effectiveness was estimated as the incremental cost per quality-adjusted life-year (QALY) of each strategy compared with the next most effective, taking a health-service perspective and a lifetime horizon. Results: Sensitivity and specificity (95% predictive interval) were 77% (29–96%) and 93% (46–100%) for troponin I, 80% (33–97%) and 91% (53–99%) for troponin T (99th percentile threshold), 81% (50–95%) and 80% (26–98%) for quantitative heart-type fatty acid-binding protein (H-FABP), 68% (11–97%) and 92% (20–100%) for qualitative H-FABP, 77% (19–98%) and 39% (2–95%) for ischaemia-modified albumin and 62% (35–83%) and 83% (35–98%) for myoglobin. CTCA had 94% (61–99%) sensitivity and 87% (16–100%) specificity for CAD. Positive CTCA and positive-exercise ECG had relative risks of 5.8 (0.6–24.5) and 8.0 (2.3–22.7) for MACEs. In most scenarios in the economic analysis presentation, high-sensitivity troponin measurement was the most effective strategy with an incremental cost-effectiveness ratio (ICER) of less than the £20,000–30,000/QALY threshold (ICER £7487–17,191/QALY). CTCA appeared to be the most cost-effective strategy for patients with a negative troponin, with an ICER of £11,041/QALY. However, when a lower MACE rate was assumed, CTCA had a high ICER (£262,061/QALY) and the no-testing strategy was optimal. Limitations: There was substantial variation between the primary studies and heterogeneity in their results. Findings of the economic model were dependent on assumptions regarding the value of detecting and treating positive cases. Conclusions: Although presentation troponin has suboptimal sensitivity, measurement of a 10-hour troponin level is unlikely to be cost-effective in most scenarios compared with a high-sensitivity presentation troponin. CTCA may be a cost-effective strategy for troponin-negative patients, but further research is required to estimate the effect of CTCA on event rates and health-care costs. Funding: The National Institute for Health Research Health Technology Assessment programme.

The article focuses on a research study conducted to review the outcomes of conventional exercise electrocardiography (XECG), single-photon emission computed tomography (SPECT) and coronary computed tomography angiography (coronary CTA) in patients suffering with stable coronary artery disease (CAD). It concluded that up-front diagnostic performance of coronary (CTA) was better than XECG and SPECT.

Abstract: Background: Myocardial ischemia has been shown to be associated with increased levels of B-type natriuretic peptide (BNP). However, it remains unclear whether and how BNP levels could be used clinically in patients with suspected exercise-induced myocardial ischemia. Methods: We enrolled 274 consecutive patients with suspected exercise-induced myocardial ischemia referred for evaluation by rest/bicycle myocardial perfusion single-photon emission computed tomography (SPECT). All clinical information available to the treating cardiologist was used to quantify the clinical judgment regarding the presence of myocardial ischemia using a visual analogue scale twice: once before and once after bicycle exercise stress testing. BNP measurements were obtained before, immediately after, and 2 hours after stress testing in a blinded manner. The presence of myocardial ischemia was adjudicated on the basis of perfusion SPECT combined with coronary angiography findings. Results: Exercise-induced myocardial ischemia was adjudicated to be present in 103 patients (38%). BNP levels were significantly higher at all time points in patients with myocardial ischemia compared with those without (P < .01 for all). The accuracy of BNP levels as quantified by the area under the receiver operating characteristic curve (AUC) was similar among the time points evaluated (AUC, 0.677-0.697). Combining clinical judgment before exercise testing with BNP levels at rest increased diagnostic accuracy from AUC 0.708 to 0.754 (P = .018). When combining clinical judgment after exercise testing with BNP levels, AUC increased from 0.741 to 0.771 (P = .055). Conclusions: Combining clinical judgment with BNP levels increased the diagnostic accuracy regarding the presence of myocardial ischemia. [Copyright &y& Elsevier]

Background: Electrocardiographic methods still provide the bulk of cardiovascular diagnostics. Cardiac ischemia is associated with typical alterations in cardiac biosignals that have to be measured, analyzed by mathematical algorithms and allegorized for further clinical diagnostics. The fast growing fields of biomedical engineering and applied sciences are intensely focused on generating new approaches to cardiac biosignal analysis for diagnosis and risk stratification in myocardial ischemia. Objectives: To present and review the state of the art in and new approaches to electrocardiologic methods for non-invasive detection and risk stratification in coronary artery disease (CAD) and myocardial ischemia; secondarily, to explore the future perspectives of these methods. Methods: In follow-up to the Expert Discussion at the 2008 Workshop on "Biosignal Analysis" of the German Society of Biomedical Engineering in Potsdam, Germany, we comprehensively searched the pertinent literature and databases and compiled the results into this review. Then, we categorized the state-of-the-art methods and selected new approaches based on their applications in detection and risk stratification of myocardial ischemia. Finally, we compared the pros and cons of the methods and explored their future potentials for cardiology. Results: Resting ECG, particularly suited for detecting ST-elevation myocardial infarctions, and exercise ECG, for the diagnosis of stable CAD, are state-of-the-art methods. New exercise-free methods for detecting stable CAD include cardiogoniometry (CGM); methods for detecting acute coronary syndrome without ST elevation are Body Surface Potential Mapping, functional imaging and CGM. Heart rate variability and blood pressure variability analyses, microvolt T-wave alternans and signal-averaged ECG mainly serve in detecting and stratifying the risk for lethal arrythmias in patients with myocardial ischemia or previous myocardial infarctions. Telemedicine and ambient-assisted living support the electrocardiological monitoring of at-risk patients. Conclusions: There are many promising methods for the exercise-free, non-invasive detection of CAD and myocardial ischemia in the stable and acute phases. In the coming years, these new methods will help enhance state-of-the-art procedures in routine diagnostics. The future can expect that equally novel methods for risk stratification and telemedicine will transition into clinical routine.

Objectives: This study was designed to determine the prognostic value of multidetector coronary computed tomography angiography (CTA) in relation to exercise electrocardiography (XECG) findings. Background: The prognostic usefulness of coronary CTA findings of coronary artery disease in relation to XECG findings has not been explored systematically. Methods: Patients with suspected coronary artery disease who had undergone both coronary CTA and XECG (<90 days between tests) from 2003 through 2009 were enrolled retrospectively. Coronary CTA results were classified according to the severity of maximal stenosis (normal, mild: <40% of luminal stenosis, moderate: 40% to 69%, severe: ≥70%), XECG results were categorized as positive and negative, and Duke XECG score was calculated. Clinical follow-up data were collected for major adverse cardiac events (MACE): cardiac death, nonfatal myocardial infarction, unstable angina requiring hospitalization, and revascularization after 90 days from index coronary CTA. C-statistics were calculated to compare discriminatory values of each test. Results: Among the 2,977 (58 ± 10 years) study patients, 12% demonstrated positive XECG results. By coronary CTA, patients were categorized as normal (56%) or having mild (26%), moderate (13%), or severe (5%) disease. During a median follow-up of 3.3 years (interquartile range: 2.3 to 4.6), 97 MACE were observed and the 5-year cumulative event rate was 3.6% (95% confidence interval: 3.0 to 4.3). Although both XECG (C-statistic: 0.790) and coronary CTA (C-statistic: 0.908) improved risk stratification beyond clinical risk factors (C-statistic: 0.746, p < 0.05 for all), XECG in addition to coronary CTA (C-statistic: 0.907) did not provide better discrimination than coronary CTA alone (p = 0.389). In subgroup analyses, coronary CTA stratified risk of MACE in groups with both positive and negative XECG results (all p < 0.001 for trend). However, positive XECG results predicted risk of MACE on coronary CTA only in the moderate stenosis group (hazard ratio: 2.58, 95% confidence interval: 1.29 to 5.19, p = 0.008) and severe stenosis group (hazard ratio: 2.28, 95% confidence interval: 1.19 to 4.38, p = 0.013). Conclusions: In patients with suspected coronary artery disease, coronary CTA discriminates future risk of MACE in patients independent of XECG results. Compared with coronary CTA, XECG has an additive prognostic value only in patients with moderate to severe stenosis on coronary CTA. [Copyright &y& Elsevier]

Aims Recent data have shown that exercise electrocardiogram (ECG) has no incremental prognostic value over clinical and rest ECG parameters in chest pain patients without a history of coronary artery disease (CAD). The incremental prognostic value of stress echocardiography (SE) in this population is unknown. Methods and results Accordingly, 547 consecutive patients (68 ± 4.9 years) with chest pain but no previous history of CAD, referred for SE (exercise and dobutamine), were identified. Patients were followed up for death and acute myocardial infarction (AMI). At a median follow-up period of 28 months, there were a total of 35 hard cardiac events (5 deaths and 30 non-fatal AMI). Among the prognostic clinical, resting/stress ECG, and SE data, univariate predictors were the Framingham risk score (P = 0.025), diabetes (P = 0.06), hypercholesterolaemia (P = 0.06), stress ECG ischaemia (P = 0.044), stress heart rate (P = 0.019), and SE-determined ischaemic burden (stress–rest wall thickening score index; P < 0.001). In a multivariate model, ischaemic burden was the only independent predictor of events (P < 0.001). SE also showed incremental prognostic value over and above clinical (Framingham's risk score) and stress ECG changes in a global χ2 model. This was true also for patients undergoing only exercise SE (n = 347). Conclusion SE provides both independent and incremental prognostic value for the prediction of hard cardiac events in chest pain patients without a previous history of CAD—over and above clinical, ECG, and stress ECG data. [ABSTRACT FROM AUTHOR]

Abstract: Aim: To prospectively assess the prognostic value of the Stress-Recovery Index (SRI) in women with typical chest pain. Methods: 165 women without known coronary artery disease, who complained of typical chest pain, were exercise tested and prospectively followed-up for the occurrence of cardiac death and nonfatal myocardial infarction. SRI, defined as the difference in absolute values between the area of heart rate-adjusted ST-segment depression during exercise and recovery, was derived in all. Clinical data, resting ejection fraction, and exercise testing data were entered into a sequential Cox''s model; SRI was entered last. Model validation was performed by bootstrap adjusted by the degree of optimism in estimates. Survival curves were set up using Kaplan–Meier method and compared by the log-rank test. Results: During a median follow-up time of 42 months, 19 events (14 cardiac deaths and 5 nonfatal myocardial infarction) were observed. Age (hazard ratio 3.58, 95% CI 0.87–15) and SRI (hazard ratio 0.62, 95% CI 0.42–0.92) were multivariate predictors of outcome. However, the addition of SRI increased the prognostic power of the model on top of clinical and exercise testing variables, as demonstrated by the significant (p =0.003) increase of the area under the ROC curve of the risk function. Survival analysis showed ascending SRI quartiles to identify a significant (p =0.005) increase in event-free survival. Conclusions: SRI is of value in predicting outcome of women with typical chest pain and provides additional prognostic information on the top of clinical and standard exercise testing data. [Copyright &y& Elsevier]

We compared the cost effectiveness of recent approaches [coronary angiography and calcium scoring using computed tomography (CT) and stress magnetic resonance imaging (MRI)] to the diagnosis of coronary artery disease (CAD) with those of the traditional diagnostic modalities [conventional angiography (CATH), exercise ECG, and stress echocardiography] using a decision tree model. For patients with a 10% to 50% pretest likelihood of coronary artery disease, non-invasive coronary angiography using CT was the most cost effective approach, with costs per correctly identified CAD patient of euro4,435 (10% likelihood) to euro1,469 (50% likelihood). Only for a pretest likelihood of 30% to 40% was calcium scoring using CT more cost effective than any of the traditional diagnostic modalities, while MRI was not cost effective for any pretest likelihood. At a pretest likelihood of 60%, CT coronary angiography and CATH were equally effective, while CATH was most cost effective for a pretest likelihood of at least 70%. In conclusion, up to a pretest likelihood for coronary artery disease of 50%, CT coronary angiography is the most cost-effective procedure, being superior to the other new modalities and the most commonly used traditional diagnostic modalities. With a very high likelihood for disease (above 60%), CATH is the most effective procedure from the perspective of society. [ABSTRACT FROM AUTHOR]

Background: There are no reliable non-invasive markers of restenosis after percutaneous transluminal coronary angioplasty (PTCA). The aim of our study was to measure changes in QT interval dispersion after PTCA and to determine whether restenosis subsequently affects QT interval dispersion. Methods and Results: Fifty-six consecutive patients – 41 men and 15 women (mean age: 56.2 ±8.3 years) – with isolated stenosis of the left anterior descending artery who underwent successful PTCA were studied. A symptom-limited treadmill exercise test was performed within 7 days after PTCA and then again before repeated angiography. Repeated coronary angiography revealed restenosis in 15 patients (26.8%) and no signs of significant stenosis in 41 patients (73.2%). QT interval dispersion in the group of patients with restenosis measured before exercise increased from baseline 34 ± 7 to 49 ± 15 ms after 6 months (p < 0.01) and QT interval dispersion measured immediately after exercise increased from baseline 38 ± 4 to 68 ± 21 ms after 6 months (p < 0.001). In contrast, patients without restenosis showed no significant changes in QT interval dispersion measured before (baseline: 34 ± 9 ms; after 6 months 33 ± 12 ms; p = NS) and immediately after exercise (baseline: 34 ± 12 ms; after 6 months: 33 ± 10; p = NS). When QT interval dispersion ≥60 ms (measured 6 months after PTCA procedure) was considered as a potential marker of restenosis, this indicator had very high sensitivity and specificity when measured immediately after exercise (80 and 95% respectively). Conclusions: QT interval dispersion significantly increases in the group of patients with documented restenosis and may be a simple, non-invasive marker of restenosis. However, further studies are needed to confirm this observation. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]