Positive Stress Test Results Research Articles

Platelet distribution width and saphenous vein disease in patients after CABG

Platelets are involved in the pathogenesis of atherosclerosis. The inflammatory process in atherosclerosis may cause an increase in red blood cell distribution width (RDW) and platelet distribution width (PDW) values. Therefore, in this study we aimed to investigate whether PDW and RDW are associated with the patency of saphenous vein graft in patients at least 1year after coronary artery bypass graft (CABG) surgery. Patients who had undergone CABG surgery at least 1year previously with at least one saphenous vein graft were included in the study population. Patients were referred to cardiac catheterization for stable anginal symptoms or positive stress test results. Before coronary angiography, all patients referred had routine blood tests including RDW and PDW values. Saphenous vein grafts were found to be patent in 69patients and occluded in 40patients. Although RDW levels were similar between patients with patent and occluded grafts (13.1 ± 1.1% and 13.2 ± 0.7% respectively, p = 0.37), PDW levels were significantly different between the two groups (13.1 ± 1.3% and 14.1 ± 1.1 respectively, p = 0.03). Although time after CABG operation differs significantly between the two groups (p < 0.001), multiple logistic regression analyses showed that PDW levels were found to be significantly associated with the patency of vein graft (β = 1.682, 95%CI 1.117-2.532, p = 0.013). Our results showed that PDW levels were higher in patients with an occluded saphenous vein graft. However no association was found between the saphenous vein graft disease and RDW values. To verify this relationship between PDW values and saphenous vein graft patency, further investigations are needed.

Ganglions of the Wrist and Associated Triangular Fibrocartilage Lesions: A Prospective Study in Arthroscopically-treated Patients

Wrist ganglions are the most common soft tissue tumors of the hand and wrist and can occur at any age. Their etiology remains controversial. A high prevalence of associated intrinsic ligamentous lesions has been described. We hypothesized that painful wrist ganglions are an indicator of an underlying joint abnormality, particularly of lesions of the triangular fibrocartilage complex (TFCC). The aim of our study was to prospectively determine the prevalence of associated TFCC lesions in patients with painful wrist ganglions. Forty-six patients (35 women, 11 men; mean age, 36 ± 11 y; range, 18-57 y) with painful wrist ganglions (20 radiopalmar and 26 dorsal) had surgery from January 2008 to June 2010. There were 18 primary and 28 recurrent ganglions. Clinical examinations, pain score evaluations, disabilities in daily life evaluations, plain radiographs, and magnetic resonance imaging were obtained before arthroscopic resection. Concomitant intrinsic lesions of the wrist were assessed with magnetic resonance imaging and re-evaluated by arthroscopy. All ganglions were successfully resected. Overall, arthroscopy identified 22 TFCC lesions (48%) and 2 intracarpal ligament lesions. The TFCC perforations were more commonly associated with radiopalmar ganglions with a positive ulnocarpal stress test result and with recurrent radiopalmar ganglions. At 1-year follow-up, all patients were meaningfully improved in terms of pain and disabilities in daily life. Arthroscopy allows for the simultaneous treatment of ganglions and other pathologies. Therefore, arthroscopy should be contemplated as the primary treatment option for patients with painful ganglions of the wrist if they are in a radiopalmar location with a positive ulnocarpal stress test and for patients with recurrent radiopalmar ganglions, which are also highly associated with TFCC abnormalities. Therapeutic IV.

The prognostic value of myocardial perfusion scintigraphy compared to coronary angiography in women with positive stress test results

Modern diagnostic strategy in coronary artery disease (CAD) makes it necessary not only to establish a diagnosis but also to assess the cardiovascular risk. It is not clear which strategy should be followed in the case of women with positive ECG stress test results to assess prognosis and start appropriate diagnostics and treatment.The aim of the study was to assess the prognostic value of myocardial perfusion scintigraphy in comparison with coronary angiography in women suspected of CAD and with positive ECG stress test results. The study population comprised 115 women (mean age 58.08 ± 8.8 years) suspected of CAD, with a history of chest pain and positive stress test results, who underwent myocardial perfusion scintigraphy. In 58 women coronary angiography was performed as the next step of the diagnostic procedure. All the patients were interviewed and had a physical examination, including the assessment of the cardiovascular risk in accordance with the SCORE (Systematic Coronary Risk Evaluation) scale and the probability of CAD (POST-TEST) in accordance with the ESC guidelines. The gated single photon emission computed tomography (GSPECT) with Tc-99m-MIBI was considered positive if moderate perfusion changes were observed in at least two segments or severe reversible perfusion disorders were found, regardless of the number of involved segments.The degree of coronary stenosis was assessed visually and changes greater than 50% stenosis of the luminal diameter were considered haemodynamically significant. The evaluation period covered 43.2 ± 30.8 months on average. The sensitivity of myocardial perfusion scintigraphy against cardiovascular events was 100% and the sensitivity of coronary angiography was 92.3%. The specificity was 93.1%and 88.9% respectively. The PPV of scintigraphy for cardiovascular events was 65% and of coronary angiography was 70.6%. The NPV was 100% and 97.6%respectively. The accuracy of myocardial perfusion scintigraphy for cardiovascular events was 93.9% and the accuracy of coronary angiography for cardiovascular events was 89.7%. The survival analysis confirmed the high prognostic value of SPECT and coronary angiography. However, if compared, myocardial perfusion scintigraphy was a better predictor of survival without cardiovascular events than coronary angiography was (c2 = 9.39, p < 0.01).The most important factors in assessing the cardiovascular risk in the study population included: positive result of myocardial perfusion scintigraphy, positive result of coronary angiography,and high SCORE and high POST-TEST values. Myocardial perfusion scintigraphy is superiorto coronary angiography in the prediction of necessary revascularisation procedures in women suspected of coronary artery disease and with positive stress test results.

The prognostic value of myocardial perfusion scintigraphy compared to coronary angiography in women with positive stress test results

BACKGROUND: Modern diagnostic strategy in coronary arterydisease (CAD) makes it necessary not only to establish a diagnosisbut also to assess the cardiovascular risk. It is not clearwhich strategy should be followed in the case of women withpositive ECG stress test results to assess prognosis and startappropriate diagnostics and treatment.The aim of the study was to assess the prognostic value ofmyocardial perfusion scintigraphy in comparison with coronaryangiography in women suspected of CAD and with positive ECGstress test results. MATERIAL AND METHODS: The study population comprised115 women (mean age 58.08 ± 8.8 years) suspected of CAD, witha history of chest pain and positive stress test results, who underwent myocardial perfusion scintigraphy. In 58 women coronaryangiography was performed as the next step of the diagnosticprocedure. All the patients were interviewed and had a physicalexamination, including the assessment of the cardiovascularrisk in accordance with the SCORE (Systematic Coronary RiskEvaluation) scale and the probability of CAD (POST-TEST) inaccordance with the ESC guidelines. The gated single photonemission computed tomography (GSPECT) with Tc-99m-MIBIwas considered positive if moderate perfusion changes wereobserved in at least two segments or severe reversible perfusiondisorders were found, regardless of the number of involved segments.The degree of coronary stenosis was assessed visuallyand changes greater than 50% stenosis of the luminal diameterwere considered haemodynamically significant. RESULTS: The evaluation period covered 43.2 ± 30.8 monthson average. The sensitivity of myocardial perfusion scintigraphyagainst cardiovascular events was 100% and the sensitivity ofcoronary angiography was 92.3%. The specificity was 93.1%and 88.9% respectively.The PPV of scintigraphy for cardiovascular events was 65% and ofcoronary angiography was 70.6%. The NPV was 100% and 97.6%respectively. The accuracy of myocardial perfusion scintigraphy forcardiovascular events was 93.9% and the accuracy of coronaryangiography for cardiovascular events was 89.7%. The survivalanalysis confirmed the high prognostic value of SPECT and coronaryangiography. However, if compared, myocardial perfusionscintigraphy was a better predictor of survival without cardiovascularevents than coronary angiography was (c2 = 9.39, p &lt; 0.01).The most important factors in assessing the cardiovascular riskin the study population included: positive result of myocardialperfusion scintigraphy, positive result of coronary angiography,and high SCORE and high POST-TEST values. CONCLUSIONS: Myocardial perfusion scintigraphy is superiorto coronary angiography in the prediction of necessary revascularisation procedures in women suspected of coronary arterydisease and with positive stress test results.

Cost-effectiveness of a Novel Indication of Computed Tomography of the Coronary Arteries

A common strategy for excluding coronary artery disease among patients presenting with low-risk chest pain is observation unit (OU) admission with serial cardiac biomarkers and stress testing for cardiac risk stratification. Patients with positive- or indeterminate-stress tests are often admitted for cardiac catheterization despite a low likelihood of disease. The aim of this study is to estimate the cost-effectiveness of computed tomography of the coronary arteries (CTCA) in the OU for the evaluation of low-risk chest pain patients with indeterminate- or positive-stress test results. We conducted a decision analytic study to compare health outcomes and costs between 3 cardiac risk-stratification strategies in a population of patients at low cardiac risk admitted to the OU, who later had indeterminate- or abnormal-stress tests. Our population and test characteristics were based on data obtained both from the published literature and from a retrospective cohort review previously performed at our institution. The 3 strategies compared were (1) A CTCA strategy in which patients with positive- or indeterminate-stress tests subsequently underwent CTCA, and only received catheterization if results were positive, (2) A standard-of-care arm in which all patients with positive- or indeterminate-stress tests were admitted for catheterization, and (3) A do-nothing strategy in which all patients were discharged home after stress testing regardless of outcome. Outcomes measured were cost of care and life expectancy. Sensitivity analysis was performed with a multivariate Monte Carlo methodology. Both the CTCA and standard-of-care strategies dominated the do-nothing strategy in the base case. When comparing the standard-of-care with the CTCA strategy, the incremental cost-effectiveness ratio was $3,423,309 per additional year of life gained. Sensitivity analysis showed that below a willingness to pay of $600,000 per additional year of life, CTCA was the most likely strategy to be cost-effective. In this computer-modeled analysis, the addition of CTCA following positive- or indeterminate-stress tests to an OU cardiac risk-stratification pathway for low-risk chest pain patients achieved significant cost savings with a small decrease in life expectancy per patient. Adding CTCA after indeterminate- or positive-stress test results is a cost-effective intervention for further risk-stratifying low-risk chest pain patients in the OU setting before proceeding to traditional coronary angiography.

Relation of Impaired Coronary Microcirculation to Increased Urine Albumin Excretion in Patients With Systemic Hypertension and No Epicardial Coronary Arterial Narrowing

Coronary flow reserve (CFR) is impaired and urinary albumin excretion is increased in patients with essential hypertension. Our aim was to investigate the associations between CFR and cardiac and renal damage in hypertensives. For this purpose we studied 37 never-treated hypertensives (57.9 years old, 16 men) without chest pain but with a positive ischemia stress test result and normal coronary arteries on coronary angiogram. CFR was calculated by a 0.014-inch Doppler guidewire (Flowire, Volcano, San Diego) in the left anterior descending artery in response to bolus intracoronary administration of adenosine (60 μg) as the ratio of hyperemic to basal average peak velocity of the distal vessel. All participants underwent complete echocardiographic study including left ventricular diastolic function evaluation by tissue Doppler imaging (peak early diastolic velocity/peak atrial systolic velocity) and determination of the albumin-to-creatinine ratio (ACR). Hypertensives with low CFR (<2.5, n = 22) compared to those with high CFR (n = 15) exhibited a larger left ventricular mass index by 10.9 g/m(2) (p = 0.045) and ACR values by 10 mg/g (p <0.001). CFR was negatively correlated with logACR (r = -0.511, p = 0.001). LogACR (beta -0.792, p <0.001), male gender (beta 0.313, p = 0.005), left ventricular mass index (beta -0.329, p = 0.007), and peak early diastolic velocity/peak atrial systolic velocity (beta 0.443, p <0.001) were the only independent predictors of CFR in linear regression analysis (adjusted R(2) = 0.672). In conclusion, never-treated asymptomatic hypertensives who exhibit impaired CFR and angiographically normal epicardial arteries are characterized by intrarenal vascular damage as reflected by increased ACR. These findings suggest a plausible role of ACR estimation in the identification of hypertensive subjects with early coronary microvascular dysfunction.

Heart rate variability and turbulence to determine true coronary artery disease in patients with ST segment depression without angina during exercise stress testing

ST segment depression without angina during an exercise stress test causes diagnostic problems, particularly in non-diabetic patients. Heart rate variability (HRV) and heart rate turbulence (HRT) are used to evaluate the changes in cardiac autonomic functions and are also both decreased in patients with coronary artery disease. The aim of this study was determine the values of HRV and HRT that discriminate true coronary artery disease from false positive stress test results. Ninety non-diabetic patients who underwent diagnostic coronary angiography (CA) due to suspected coronary artery disease after ST segment depression without angina during an exercise stress test were enrolled in the study. Prior to CA, 24 hour ambulatory electrocardiogram recordings were taken and HRV and HRT parameters were calculated. Patients were divided into three groups according to the severity of their coronary lesions: (group 1 normal, group 2 non-obstructive and group 3 obstructive. There were no differences among the groups with regards to age, sex, medical history, medications, systolic and diastolic blood pressures, body mass index, fasting glucose, anemia and thyroid status, lipid profile and creatinine clearance. HRV parameters and turbulence slope (TS) were significantly lower while turbulence onset (TO) was significantly higher in group 3 than groups 1 and 2. According to the cut-off values calculated using ROC analysis, SDNN≤69.63 msec, TO > 0.14%, and TS≤2.78 msec/RR have high diagnostic accuracy for predicting obstructive coronary artery disease. HRV and HRT parameters may provide additional information for discriminating between patients who do and do not truly need CA.

Intraoperative Assessment of the Stability of the Distal Tibiofibular Joint in Supination-External Rotation Injuries of the Ankle

This study was designed to assess the sensitivity, specificity, and interobserver reliability of the hook test and the stress test for the intraoperative diagnosis of instability of the distal tibiofibular joint following fixation of ankle fractures resulting from supination-external rotation forces. We conducted a prospective study of 140 patients with an unstable unilateral ankle fracture resulting from a supination-external rotation mechanism (Lauge-Hansen SE). After internal fixation of the malleolar fracture, a hook test and an external rotation stress test under fluoroscopy were performed independently by the lead surgeon and assisting surgeon, followed by a standardized 7.5-Nm external rotation stress test of each ankle under fluoroscopy. A positive stress test result was defined as a side-to-side difference of >2 mm in the tibiotalar or the tibiofibular clear space on mortise radiographs. The sensitivity and specificity of each test were calculated with use of the standardized 7.5-Nm external rotation stress test as a reference. Twenty-four (17%) of the 140 patients had a positive standardized 7.5-Nm external rotation stress test after internal fixation of the malleolar fracture. The hook test had a sensitivity of 0.25 (95% confidence interval, 0.12 to 0.45) and a specificity of 0.98 (95% confidence interval, 0.94 to 1.0) for the detection of the same instabilities. The external rotation stress test had a sensitivity of 0.58 (95% confidence interval, 0.39 to 0.76) and a specificity of 0.96 (95% confidence interval, 0.90 to 0.98). Both tests had excellent interobserver reliability, with 99% agreement for the hook test and 98% for the stress test. Interobserver agreement for the hook test and the clinical stress test was excellent, but the sensitivity of these tests was insufficient to adequately detect instability of the syndesmosis intraoperatively.

Physical fitness cannot be used to predict the likelihood of acute coronary syndromes in ED patients with chest pain

Objective The objective of the study was to explore the association between physical fitness and the likelihood of acute coronary syndrome (ACS) in patients presenting to the emergency department (ED) with chest pain (CP). We hypothesized that the likelihood of ACS would be lower in physically fit patients and higher in patients with exercise-induced CP. Methods The study involved a prospective, descriptive cohort in an academic suburban ED. Subjects were ED patients with CP admitted for suspected ACS. Demographic and clinical data were collected by trained research assistants using standardized forms. Patients were surveyed on level of fitness and whether they had ever experienced anginal type symptoms during exercise. Acute coronary syndrome was considered present if the patient had electrocardiographic evidence of infarction or ischemia; elevated troponin I levels; greater than 70% stenosis of culprit coronary artery; or a positive nuclear, echocardiographic, or treadmill stress test result. Patients readmitted within 30 days for reinfarction, cardiogenic shock, or arrhythmias were also considered to have ACS. The association between physical fitness and ACS was determined using χ 2 tests and odds ratios (ORs). Results One hundred patients were enrolled. Mean age was 55.8 (±15.3) years; 36% were female; 85% were white. Thirteen (13%) patients had positive troponins, 22 of 36 catheterized patients had greater than 70% coronary artery stenosis, and 6 (6%) had abnormal stress test results. There were no deaths or reinfarctions within 30 days. The rate of ACS was similar in patients who were physically fit and those who were not (24% vs 37%; OR, 0.5 [95% confidence interval, 0.2-1.3]) and in patients who had experienced exercise-induced CP and those who had not (32% vs 29%; OR, 1.2 [95% confidence interval, 0.4-3.2]). Neither the frequency nor the intensity of exercise was associated with ACS. Conclusions Physically fit patients with CP were as likely to have ACS as those not physically fit. A history of exercise-induced CP was not associated with an increased likelihood of ACS.

Patients' and Cardiologists' Perceptions of the Benefits of Percutaneous Coronary Intervention for Stable Coronary Disease

It is unclear whether patients understand that percutaneous coronary intervention (PCI) reduces only chronic stable angina and not myocardial infarction (MI) or associated mortality. To compare cardiologists' and patients' beliefs about PCI. Survey. Academic center. 153 patients who consented to elective coronary catheterization and possible PCI, 10 interventional cardiologists, and 17 referring cardiologists. Patients' and cardiologists' beliefs about benefits of PCI. All cardiologists reported beliefs about PCI for patients in hypothetical scenarios. Interventional cardiologists also reported beliefs for study patients who underwent PCI. Of 153 patients, 68% had any angina, 42% had activity-limiting angina, 77% had a positive stress test result, and 29% had had previous MI. The 53 patients who underwent PCI were more likely than those who did not to have a positive stress test result, but angina was similar in both groups. Almost three quarters of patients thought that without PCI, they would probably have MI within 5 years, and 88% believed that PCI would reduce risk for MI. Patients were more likely than physicians to believe that PCI would prevent MI (prevalence ratio, 4.25 [95% CI, 2.31 to 7.79]) or fatal MI (prevalence ratio, 4.83 [CI, 2.23 to 10.46]). Patients were less likely than their physicians to report pre-PCI angina (prevalence ratio, 0.79 [CI, 0.67 to 0.92]). For the scenarios, 63% of cardiologists believed that the benefits of PCI were limited to symptom relief. Of cardiologists who identified no benefit of PCI in 2 scenarios, 43% indicated that they would still proceed with PCI in these cases. The study was small and conducted at 1 center, and information about precatheterization counseling was limited. Cardiologists' beliefs about PCI reflect trial results, but patients' beliefs do not. Discussions with patients before PCI should better explain anticipated benefits. None.

Sex differences in clinical presentation, management and outcome in emergency department patients with chest pain

We sought to assess sex differences in clinical presentation, management and outcome in emergency department (ED) patients with chest pain, and to measure the association between female sex and coronary angiography within 30 days. We conducted a prospective cohort study in an urban academic ED between Jul. 1, 2007, and Apr. 1, 2008. We enrolled patients over 24 years of age with chest pain and possible acute coronary syndrome (ACS). Among the 970 included patients, 386 (39.8%) were female. Compared with men, women had a lower prevalence of known coronary artery disease (21.0% v. 34.2%, p < 0.001) and a lower frequency of typical pain (37.1% v. 45.7%, p = 0.01). Clinicians classified a greater proportion of women as having a low (< 10%) pretest probability for ACS (85.0% v. 76.4%, p = 0.001). Despite similar rates of electrocardiography, troponin T and stress testing between sexes, there was a lower rate of acute myocardial infarction (AMI) (4.7% v. 8.4%, p = 0.03) and positive stress test results (4.4% v. 7.9%, p = 0.03) in women. Women were less frequently referred for coronary angiography (9.3% v. 18.9%, p < 0.001). The adjusted association between female sex and coronary angiography was not significant (odds ratio 0.63, 95% confidence interval 0.37-1.10). Women had a lower rate of AMI and a lower rate of positive stress test results despite similar rates of testing between sexes. Although women were less frequently referred for coronary angiography, these data suggest that sex differences in management were likely appropriate for the probability of disease.

Cost-Effectiveness of Coronary CT Angiography in Evaluation of Patients Without Symptoms Who Have Positive Stress Test Results

Patients without symptoms who have positive stress test results are often referred for diagnostic catheter angiography in an evaluation for coronary artery disease (CAD). The purpose of this study was to use decision tree analysis to determine the cost-effectiveness and radiation dose that would result from performing coronary CT angiography (CTA) before catheterization. A decision tree was constructed to compare the false-negative rates, false-positive rates, costs, and radiation exposure of direct referral of patients for cardiac catheterization with the values associated with performing coronary CTA before catheterization. We assumed that patients referred for coronary CTA proceed to catheterization only when significant disease is identified. Costs for coronary CTA and diagnostic catheterization were obtained from the 2009 physician Medicare fee schedule. Sensitivity, specificity, and radiation dose were obtained by literature review. Cost reduction with coronary CTA depends on the prevalence of coronary artery disease, but overall costs are reduced as long as the prevalence is less than 85%. At a 50% prevalence of coronary artery disease, performing coronary CTA before cardiac catheterization results in an average cost saving of $789 per patient with a false-negative rate of 2.5% and average additional radiation exposure of 1-2 mSv. Performing coronary CTA before cardiac catheterization is a cost-effective strategy in the care of patients without symptoms who have positive stress test results when the probability that the patient has significant coronary artery disease is less than 50%. The false-negative rate with this strategy compares favorably with the false-negative rate of stress testing. The use of coronary CTA in this role can avoid many unnecessary cardiac catheterization procedures.

Relation Between Framingham Risk Categories and the Presence of Functionally Relevant Coronary Lesions as Determined on Multislice Computed Tomography and Stress Testing

Noninvasive assessment of subclinical atherosclerosis by multislice computed tomographic (MSCT) coronary angiography and demonstration of significant, flow-limiting coronary artery disease (CAD) by stress testing may improve patients' risk stratification. However, data relating the complementary information provided by these noninvasive techniques to traditional risk assessment are scarce. In 255 subjects (45% women, mean age 54 +/- 12 years) without known CAD, 64-slice MSCT coronary angiography and stress testing (exercise electrocardiographic test or myocardial perfusion imaging) were performed. Framingham risk score (FRS) was calculated from baseline characteristics (50% low, 22% intermediate, 28% high). Angiograms showing atherosclerosis were classified as obstructive (> or =50% luminal narrowing) CAD or not. Stress tests were classified as normal or abnormal. Multislice computed tomogram identified 155 patients (61%) with CAD, of whom 78 (31%) showed obstructive CAD. A positive stress test result was observed in 36 patients (46%) with obstructive CAD. In line with increasing FRS categories, a significant increase in the prevalence of functionally relevant obstructive CAD was observed (6% low vs 45% intermediate vs 63% high, p <0.001). In conclusion, a strong positive relation exists between FRS and prevalence of functionally relevant obstructive CAD. Selective use of MSCT coronary angiography and stress testing may refine the traditional risk assessment of CAD events, especially in patients deemed at intermediate and high risk.

Cardiovascular complications of obesity surgery in patients with increased preoperative cardiac risk

Background Obesity surgery reduces the incidence of long-term cardiovascular events by modifying the associated risk factors. The derived benefits of weight loss surgery might be counterbalanced by the increased cardiovascular risks in some patients. The primary objective of the present study was to determine the rate of cardiovascular events after obesity surgery in patients considered to have an increased cardiac risk profile at a tertiary referral hospital. Methods A retrospective analysis of the data from consecutive patients who underwent obesity surgery at the Cleveland Clinic Florida was performed. The use of β-blockers, noninvasive stress testing, and perioperative events were assessed. Results The data from 154 patients who had undergone a preoperative cardiac consultation at the Cleveland Clinic Florida before obesity surgery from 2003 to 2006 were analyzed. Most patients were women (n = 108, 69%), and 25 (16%) were >65 years old. The number of patients who received perioperative β-blockers was 72 (47%). Noninvasive stress testing was performed in 78 patients (50%). Of the 78 patients who underwent noninvasive stress testing, 25 (32%) had a positive finding. Only 1 patient with positive stress test results had an obstructive coronary artery lesion found on cardiac catheterization. A total of 5 nonfatal cardiac-related events (3.2%) occurred. The in-hospital mortality rate was 0%. Conclusion Obesity surgery in patients with established coronary heart disease or risk factors is a safe and well-tolerated procedure, with an overall low rate of cardiac events. Noninvasive stress testing in this population resulted in a high rate of false-positive results and uncommonly led to intervention.

The Limited Utility of Routine Cardiac Stress Testing in Emergency Department Chest Pain Patients Younger Than 40 Years

This is a study designed to evaluate the utility of routine provocative cardiac testing in low-risk young adult (younger than 40 years) patients evaluated for an acute coronary syndrome in an emergency department (ED) setting. This was a retrospective observational study of patients aged 23 to 40 years who were evaluated for acute coronary syndrome in an ED-based chest pain unit from March 2004 to September 2007. All patients had serial cardiac biomarker testing to rule out myocardial infarction and then underwent provocative cardiac testing to identify the presence of myocardial ischemia. Patients were excluded from the study if they had known coronary artery disease, had ECG findings diagnostic of myocardial infarction or ischemia, or self-admitted, or tested positive for cocaine use. Of the 220 patients who met inclusion criteria, 6 patients (2.7%; 95% confidence interval 1% to 5.8%) had positive stress test results. Among these 6 patients, 4 underwent subsequent coronary angiography that demonstrated no obstructive coronary disease, suggesting the initial provocative study was falsely positive. For the remaining 2 patients, no diagnostic angiography was performed. Discounting the patients who had negative angiography results, only 2 of 220 study patients (0.9%; 95% confidence interval 0.1% to 3.2%) had a provocative test result that was positive for myocardial ischemia. In our study, a combination of age younger than 40 years, nondiagnostic ECG result, and 2 sets of negative cardiac biomarker results at least 6 hours apart identified a patient group with a very low rate of true-positive provocative testing. Routine stress testing added little to the diagnostic evaluation of this patient group and was falsely positive in all patients who consented to diagnostic coronary angiography (4 of 6 cases).

Diagnostic Uncertainty and Costs Associated With Current Emergency Department Evaluation of Low Risk Chest Pain

Of all stress tests done in low risk Emergency Department observation units (OU), a small, but significant number may be reported as positive or indeterminate. The objective of this study is to quantify the prevalence and costs associated with positive and indeterminate stress tests that result in negative cardiac catheterization. Retrospective observational cohort study over 9 months. All patients undergoing the chest pain protocol who got cardiac stress testing in the OU were eligible for inclusion. Cost data were derived from an institutional activity-based cost system utilizing actual costs. Chart review was completed on all patients with positive and indeterminate stress tests and a randomly chosen sample of those with negative stress tests. Of the 1194 patients who met the inclusion criteria, 1084 (90.8%) had a negative stress test. Sixty-two (5.2%) had a positive stress test, and 48 (4.0%) had an indeterminate stress test. Of all 59 patients who underwent catheterization, 41 (69.5%) were negative cardiac catheterizations. The prevalence among all OU stress test patients of positive or indeterminate stress tests with subsequent negative cardiac catheterization was 41/1194 (3.4%; 95% CI 2.5%-4.6%). The prevalence of significant coronary artery disease at cardiac catheterization was 18/1194 (1.5%; 95% CI 1.0%-2.4%). Patients with a positive or indeterminate stress test who had a negative catheterization incurred increased OU costs ($1385 vs. $1,039, P = 0.012), total costs ($7298 vs. $1562, P < 0.001) and length of inpatient stay (1.83 days vs. 0.00 days) when compared with those who had a negative stress test. The probability of going to the OU and having a positive or indeterminate stress test resulting in a subsequent negative catheterization was double the probability of having a stress test result in catheterization that detected significant coronary artery disease. These patients incurred 5 times the total cost when compared with those patients with negative stress testing. Further investigation is warranted to determine alternative risk stratification methods for these low risk chest pain patients with positive stress tests.

Relationships of the Thrombolysis in Myocardial Infarction Frame Count With Clinical, Hemodynamic and Medicine Variables in Syndrome X Patients

The thrombolysis in myocardial infarction (TIMI) frame count was reported to reflect coronary blood flow and have prognostic value. However, such data in syndrome X was lacking. The purpose of this study was to examine the prognostic value of the TIMI frame count in syndrome X patients, compared with the normal population. The TIMI frame count was measured in 2,049 consecutive patients referred for coronary angiography from March 2003 to February 2005. Among 308 patients with normal coronary angiograms, 44 undergoing the procedure for electrophysiologic studies or valvular heart disease surveys other than angina were designated normal controls. Another 155 patients with positive stress test results were diagnosed as syndrome X. Comparisons of the two groups showed that the syndrome X patients had higher frame counts in the left anterior descending artery (40.9 ± 15.7 vs. 47.8 ± 25.4; p < 0.05) and left circumflex artery (35.2 ± 11.7 vs. 42.0 ± 18.7; p < 0.05). A similar trend was found in the right coronary artery (29.3 ± 13.5 vs. 31.9 ± 15.9; p = 0.2). The TIMI frame count in each artery of the syndrome X group was related to the patients' variables (sex, age, and body mass index), clinical variables (medication use, diabetes, hypertension, hypercholesterolemia, smoking, and family history), and hemodynamic variables (aortic systolic blood pressure and left ventricular end-diastolic pressure). By multivariate analysis, the TIMI frame counts in all arteries were significantly higher in women and lower with angiotensin-converting enzyme inhibitor (ACEI) use (both p < 0.05). The frame count in the left anterior descending was associated with diuretics use ( p < 0.05). Our TIMI frame count data confirm the presence of slow coronary flow in syndrome X patients, especially women. ACEI use shortens the counts in these patients, suggesting that ACEIs have the potential to correct the underlying hemodynamic defects in such patients.

Identifying the Vulnerable Patient with Rupture-Prone Plaque

Atherosclerotic cardiovascular disease is the leading cause of morbidity and mortality in the United States, and the obesity epidemic combined with aging of the population seems destined to increase the burden of this disease. Traditional cardiovascular risk assessment accounts for <50% of the variability in risk in the United States. Therefore, better and more effective identification of persons at high cardiovascular risk is needed. Our understanding of atherosclerosis has shifted from a focal disease whose hallmark is symptoms caused by a severe stenosis to a systemic disease characterized by endothelial dysfunction (ED) and plaque inflammation, with the potential for rupture and thrombosis mainly in those with subcritical stenosis. Under the new paradigm, clinicians require updated strategies to better assess the quality of arterial plaque. Effective tools for primary and secondary prevention of heart attack and stroke include intensive lifestyle modification, blood pressure reduction, and lipid-modifying therapies. These interventions are now understood to decrease plaque inflammation and thereby promote plaque stability. Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) appears to be a specific marker of plaque inflammation that may play a direct role in the formation of rupture-prone plaque. In contrast, traditional risk factors, lipid measurement, and most vascular imaging modalities do not directly assess the acute ischemic potential in the arterial wall. Measuring Lp-PLA(2) levels in human serum or plasma is noninvasive and relatively inexpensive. Lp-PLA(2) may provide additional clinically relevant information that shows which patients have a high level of atherosclerotic disease activity as manifested by vascular inflammation, ED, and increased risk for progression toward rupture-prone plaque.

Role of Coronary Spasm for a Positive Noninvasive Stress Test Result in Angina Pectoris Patients Without Hemodynamically Significant Coronary Artery Disease

A positive noninvasive stress test result is often considered as a false-positive indicator of coronary artery disease (CAD) when coronary angiography reveals no hemodynamically significant CAD. From January 2001 through December 2004, 5474 patients scheduled to undergo exercise electrocardiogram (ECG) [exercise ECG without imaging or exercise ECG with thallium-201 (201Tl) single photon emission tomography (SPECT)] or dipyridamole 201Tl tomography at our outpatient clinic because of chest oppressive sensation were included in this prospective study. Coronary angiography was performed when a noninvasive test result was positive for ischemia or when ischemic chest pain was suspected. Intracoronary methylergonovine testing was performed when spastic angina was suspected and coronary angiography showed no hemodynamically significant CAD. Noninvasive stress testing was positive in 113 (67%) patients with coronary spasm. Of the 53 patients who had positive exercise ECG (exercise ECG with or without imaging), ST depression was found in 50 patients and ST elevationin in 3 patients. Multivessel spasm was found in 6 (15%), 6 (15%), and 7 (21%) of the patients with a positive result on exercise ECG without imaging, exercise ECG with 201Tl SPECT, and dipyridamole 201Tl SPECT, respectively. There was no significant difference in the results of noninvasive stress testing and the number of vessels with coronary spasm (1-vessel spasm versus multivessel spasm) among these 3 noninvasive stress testing groups. Intracoronary ergonovine testing induced coronary spasm in over 50% of patients who had suspected ischemic chest pain, a positive noninvasive stress test, and no hemodynamically significant CAD.

Prognostic Value of Early Exercise Testing After Coronary Stent Implantation

The clinical value of early exercise stress testing (EST) after coronary stenting to predict long-term clinical outcomes is unknown. Of 1,000 unselected patients who underwent coronary stenting, 446 random patients underwent early EST the day after intervention. Clinical long-term outcomes (41 +/- 20 months) were correlated with normal (n = 314 [70%]) or positive (n = 102 [23%]) EST results. Patients with inconclusive test results (n = 30 [7%]) were excluded from the analysis. Overall mortality was significantly higher in patients with positive EST results (9.3% vs 3.9%, p = 0.04). Major adverse cardiac events and cardiac mortality also tended to be higher in patients with positive stress test results (45.4% vs 35.4%, p = 0.08, and 4.1% vs 1.1%, p = 0.05, respectively). Patients with the combination of positive stress test results and incomplete revascularization appeared to be the group at highest risk for major adverse cardiac events (47.1% vs 33.3% for patients with normal stress test results and complete revascularization, p = NS). Negative stress test results reduced (odds ratio 0.329, 95% confidence interval 0.120 to 0.905, p = 0.031) and a lower ejection fraction increased (odds ratio 0.942, 95% confidence interval 0.897 to 0.989, p = 0.017) the risk for death. In conclusion, an early stress test after coronary stenting provides important prognostic information. Positive stress test results, especially in combination with incomplete revascularization, are associated with higher mortality, a trend toward more repeat revascularization procedures, and higher risk for major adverse cardiac events.