Undiagnosed Coronary Artery Disease Research Articles

Electrocardiogram-based artificial intelligence to identify prevalent coronary artery disease

Abstract Background Coronary artery disease (CAD) often goes undetected for years before it manifests and results in substantial morbidity and mortality. Some patients have neither typical risk factors nor symptomatic angina despite progressive disease. Purpose Develop a deep-learning model to detect prevalent CAD and identify people at risk for adverse events using electrocardiograms (ECG) in a primary care setting. Methods We developed a convolutional neural network using 12-lead ECG waveforms to discriminate the presence of CAD defined using diagnostic codes ("ECG2CAD"). ECG2CAD was trained on 764,670 ECGs from 137,199 individuals at the Massachusetts General Hospital (MGH). Model performance for discrimination of prevalent CAD was measured using AUROC and AUPRC, and compared against a model comprising age and sex, as well as the Pooled Cohort Equations (PCE), in three test sets independent of model training: MGH, Brigham and Women’s Hospital (BWH) and UK Biobank. ECG2CAD was assessed across subgroups of age, sex and self-reported ethnicity and for incident CAD-related events in the BWH primary care subset. Results ECG2CAD was evaluated in MGH (N=18,706 [N=6,051 cases], age 57±16 years), BWH (N=88,270 [N=27,898 cases], age 57±16 years), and UK Biobank (N=42,147 [N=1,509 cases], age 65±8 years). ECG2CAD consistently discriminated prevalent CAD (MGH: AUROC 0.782, AUPRC 0.639; BWH: AUROC 0.747, AUPRC 0.588; UK Biobank: AUROC 0.760, AUPRC 0.155) and incrementally improved upon both a model based on age and sex (p<0.01) and the PCE (p<0.01) in MGH and BWH. In the BWH primary care subset (N=51,808), model performance was consistent in subgroups defined by age, sex and self-reported ethnicity/race. The incorporation of ECG2CAD in addition to age and sex consistently improved discrimination (AUROC delta of 0.011-0.086) in all subgroups. In the BWH primary care subset with over 10 years of follow-up, we observed that either the presence of ECG2CAD-predicted CAD (HR 2.18, 95% CI 2.00-2.38, P<0.001) and ICD-based known CAD (HR 2.13, 95% CI 1.86-2.45, P<0.001) were associated with increased risk for incident myocardial infarction. The presence of both definitions was associated with an almost five-fold increase in risk (HR 4.97, 95% CI 4.51-5.48, P<0.001). The risk of incident adverse events was highest among people in the top quintile of ECG-based predicted risk (high risk) compared with people from quintile 4-2 (intermediate risk) or the lowest quintile (low risk), even when excluding those with known prevalent CAD at baseline. Conclusions Artificial intelligence-enabled analysis of the 12-lead ECG may facilitate efficient identification of individuals with possible undiagnosed CAD and inform downstream testing and preventive measures.

Clinical Characteristics of Undiagnosed Coronary Artery Disease (uCAD) in Individuals Initiating Hemodialysis

Clinical Characteristics of Undiagnosed Coronary Artery Disease (uCAD) in Individuals Initiating Hemodialysis

Artificial Intelligence in Coronary Artery Calcium Scoring Detection and Quantification.

Coronary artery calcium (CAC) is a marker of coronary atherosclerosis, and the presence and severity of CAC have been shown to be powerful predictors of future cardiovascular events. Due to its value in risk discrimination and reclassification beyond traditional risk factors, CAC has been supported by recent guidelines, particularly for the purposes of informing shared decision-making regarding the use of preventive therapies. In addition to dedicated ECG-gated CAC scans, the presence and severity of CAC can also be accurately estimated on non-contrast chest computed tomography scans performed for other clinical indications. However, the presence of such "incidental" CAC is rarely reported. Advances in artificial intelligence have now enabled automatic CAC scoring for both cardiac and non-cardiac CT scans. Various AI approaches, from rule-based models to machine learning algorithms and deep learning, have been applied to automate CAC scoring. Convolutional neural networks, a deep learning technique, have had the most successful approach, with high agreement with manual scoring demonstrated in multiple studies. Such automated CAC measurements may enable wider and more accurate detection of CAC from non-gated CT studies, thus improving the efficiency of healthcare systems to identify and treat previously undiagnosed coronary artery disease.

Systematic review and meta-analysis of prevalence of undiagnosed major cardiac comorbidities in COPD.

It is often stated that heart disease is underdiagnosed in COPD. Evidence for this statement comes from primary studies, but these have not been synthesised to provide a robust estimate of the burden of undiagnosed heart disease. A systematic review of studies using active diagnostic techniques to establish the prevalence of undiagnosed major cardiac comorbidities in patients with COPD was carried out. MEDLINE, Embase, Scopus and Web of Science were searched for terms relating to heart failure (specifically, left ventricular systolic dysfunction (LVSD), coronary artery disease (CAD) and atrial fibrillation), relevant diagnostic techniques and COPD. Studies published since 1980, reporting diagnosis rates using recognised diagnostic criteria in representative COPD populations not known to have heart disease were included. Studies were classified by condition diagnosed, diagnostic threshold used and whether participants had stable or exacerbated COPD. Random-effects meta-analysis of prevalence was conducted where appropriate. In general, prevalence estimates for undiagnosed cardiac comorbidities in COPD had broad confidence intervals, with significant study heterogeneity. Most notably, a prevalence of undiagnosed LVSD of 15.8% (11.1-21.1%) was obtained when defined as left ventricular ejection fraction <50%. Undiagnosed CAD was found in 2.3-18.0% of COPD patients and atrial fibrillation in 1.4% (0.3-3.5%). Further studies using recent diagnostic advances, and investigating therapeutic interventions for patients with COPD and heart disease are needed.

Zinc Phosphide Poisoning Precipitating Undiagnosed Coronary Artery Disease: Successfully Managed

Zinc phosphide is a rodenticide which reacts with gastric acid and produces phosphine gas which produces systemic effects. We present the case of a 32-year-old patient with alleged history of zinc phosphide ingestion. After 15 h of ingestion, he was brought to us following initial supportive care outside. All routine investigations were done. Electrocardiogram showed antero–inferior wall acute myocardial infarction with right bundle branch block. The patient developed chest pain on the next day of admission. Coronary angiography revealed stenosis of the left anterior descending artery with clot. Percutaneous coronary angioplasty with stenting was done. He was discharged in a stable condition. Zinc phosphide poisoning precipitating acute coronary syndrome is a rare entity. Although patients may not present with initial chest pain, still they need intensive monitoring.

P1.11-17 Osteoporosis, Coronary Artery Calcification, and COPD in a Lung Cancer Screening Cohort

The US Preventative Services Task Force recommends annual lung cancer screening with low-dose CT scans in adults aged 55-80 who are current smokers (or have quit within the past 15 years) with a >30 pack-years history. The advent of lung cancer screening programs provides an opportunity to assess the resultant CT scans for signs of smoking-related diseases other than lung-cancer. We aimed assess the prevalence of Chronic Obstructive Pulmonary Disease (COPD), coronary artery calcification, and osteoporosis within a lung cancer screening cohort. We recruited subjects from the National Jewish Health Lung Cancer Screening (LCS) Program. In addition to the LCS CT-scan, participants completed a DXA scan, spirometry, a sit-to-stand test, and reported their medical history. Participants were classified by GOLD (Global Initiative for Chronic Obstructive Lung Disease) spirometry grade to correlate lung function, and co-morbid disease. One hundred and thirty-five subjects participated in the study (68 males, 67 females). Mean age was 64.0 (5.8) years, and 32.6% were current smokers. 51% of the cohort had moderate to severe COPD (GOLD 2 or greater). While those who were GOLD 3 or 4 had all been previously diagnosed with COPD, 34% of those classified as GOLD 2 and 85% of GOLD 1 participants had not been previously diagnosed. Undiagnosed coronary artery disease (CAD) was common in the population. Eighty-three percent of those with CAC scores over 1000 did not report a prior diagnosis of CAD. Osteoporosis, or its precursor osteopenia, is present in a large proportion of the LCS cohort. The prevalence of osteoporotic disease increases with increasing COPD severity. Thirty-seven percent of GOLD 3 participants, and 44% of GOLD 4 participants have a Z-score of less than -2.5 (osteoporosis). Osteopenia (Z-score<-1.0) is more common, seen in 100% of GOLD 4 participants, 68% of GOLD 3 participants, 56% of GOLD 2 participants, 27% of GOLD 1, 65% of normal spirometry (GOLD 0), and 32% of PRISm participants. Increasing spirometric disease was associated with reduced physical function as measured by the sit-to-stand test and the SF-36 physical score. Patients enrolled in LCS programs often have disease other than lung cancer that may be detected using a low-dose chest CT scan. Clinicians should consider using these CT scans to screen for osteoporosis and coronary artery disease. Given the prevalence of undiagnosed COPD in LCS patients, further research should investigate a potential benefit of screening these patients for COPD using spirometry.

A HAIR OF THE DOG THAT BIT YOU: A CASE OF PASTEURELLA BACTEREMIA

SESSION TITLE: Wednesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Pasteurella is a Gram-negative coccobacillus that is commonly transmitted from cat and dog bites, and causes a wide spectrum of diseases in humans. With more people keeping pets, there is an increased risk of possible infection with zoonotic organisms. Here, we present a case of septic shock caused by Pasteurella bacteremia. CASE PRESENTATION: A 59 year-old female with no known medical history and no medical follow-up presented with her dog following a motor vehicle accident. Vitals revealed hypotension, atrial fibrillation with rapid ventricular response, fever, and respiratory distress. Physical exam revealed multiple open wounds on her lower extremities with clinical signs of cellulitis. She was intubated for hypoxic respiratory failure and found to have combined distributive and cardiogenic shock, aortic stenosis and insufficiency, and pulmonary edema. The patient was admitted to the Intensive Care Unit where she received intravenous vasopressors, Vancomycin and Piperacillin/Tazobactam. Blood cultures were positive for gram-negative rods, and speciation revealed Pasteurella multocida. She was transitioned to Ceftriaxone and steadily improved. She was eventually weaned off vasopressor support, extubated, and transferred to the general medical floors. DISCUSSION: The most common infections caused by Pasteurella multocida are local wound infections following animal bites or scratches. Cats are the source of infection in 60-80% of cases and dogs in the majority of the remainder. While local skin infections are the most common result of Pasteurella multocida, bacteremia has been shown to occur in 25-50% of patients with pneumonia, meningitis, and septic arthritis. Severe Pasteurella infections are uncommon and appear more frequently in elderly patients and those with underlying chronic diseases such as cardiovascular disease, diabetes mellitus, AIDS, malignancy, cirrhosis and chronic kidney disease. Studies have shown 70% of systemic infections in those greater than 50 years of age and 21% in ages 20-50 years. In our patient’s case, it is suspected that the route of infection was via the skin, as the patient’s dog was witnessed to be licking her lower extremity wounds. Mortality in severe disease (i.e. septicemia) is estimated to be roughly 28%. This case is unique in that our patient had no signs of immunocompromise, but given undiagnosed coronary artery disease, she may have had increased susceptibility to developing severe infection. CONCLUSIONS: Adequate hygiene is essential in preventing transmission from pets. Due to the high mortality of severe Pasteurella infection, and the increasing number of pets, it is important to have a high suspicion for pet-related infections. Reference #1: Fajfar-Whetstone, C. J., et al. "Pasteurella multocida septicemia and subsequent Pasteurella dagmatis septicemia in a diabetic patient.” Journal of clinical microbiology 33.1 (1995): 202-204 DISCLOSURES: No relevant relationships by George Elkomos-Botros, source=Web Response No relevant relationships by Ayelet Hilewitz, source=Web Response No relevant relationships by Sameer Khanijo, source=Web Response

Risk of undiagnosed coronary artery disease associated with infrapopliteal artery occlusion from a multicenter study.

Peripheral artery disease (PAD) is associated with high cardiovascular mortality. Which part of PAD with lower extremities is related to coronary artery disease (CAD) remains unknown. We hypothesized that PAD including infrapopliteal artery (IPA) occlusion was associated with CAD. A total of 260 patients who have no history of CAD or the anginal symptom, complain of the claudication or critical limb ischemia and underwent peripheral angiography were retrospectively analyzed. IPA occlusion was diagnosed with peripheral angiography, and CAD was diagnosed with the coronary angiography. A multivariate logistic regression analysis was performed to determine the predictors of silent CAD. Among them, a total of 146 patients (56.2%) had IPA occlusion. Baseline characteristics were significantly different between two groups as to the proportions of age, male, dyslipidemia (with vs. without IPA occlusion; 72.4 ± 10.8 vs. 69.1 ± 10.2; 62.3% vs. 75.4%; 38.6% vs. 52.6%, respectively, all comparisons P < 0.05). Notably, the prevalence of CAD was significantly higher in patients with IPA occlusion (50.7% vs. 34.2%, P = 0.008). On a multivariate analysis, IPA occlusion was an independent predictor for the presence of silent CAD (OR, 1.94; CI, 1.09-3.44, P = 0.024), but aortoiliac artery occlusion (OR, 1.16; CI, 0.53-2.56, P = 0.71) and femoropopliteal artery occlusion (OR, 1.02; CI, 0.57-1.83, P = 0.96) were not. IPA occlusion was associated with silent CAD. Vascular surgeons, interventional radiologists, as well as interventional cardiologists should recognize IPA occlusion as a risk factor of silent CAD.

Undiagnosed coronary artery disease in long-term type 1 diabetes. The Dialong study

AimsWe studied the total prevalence of obstructive coronary artery disease (CAD), undiagnosed CAD and absent CAD in persons with ≥45-year duration of type 1 diabetes (T1D) versus controls, and associations with mean HbA1c, LDL-cholesterol and blood pressure over 2–3 decades. MethodsWe included 76% (n = 103) of all persons with T1D diagnosed ≤1970 attending a diabetes center and 63 controls without diabetes. We collected 20–30 years of HbA1c, LDL-cholesterol and blood pressure measurements. Participants without previously diagnosed coronary heart disease (CHD) underwent Computed Tomography Coronary Angiography (CTCA). Undiagnosed obstructive CAD was defined as any coronary stenosis >50% on CTCA, absent CAD as no detected plaque, and total obstructive CAD as either obstructive CAD on CTCA or previous CHD diagnosis. ResultsThe prevalence of undiagnosed, absent and obstructive CAD was 24% (21/88), 16% (14/88) and 35% (36/103) in T1D versus 10% (6/60), 50% (30/60) and 14% (9/63) in controls (all p < 0.05). Mean HbA1c was associated with undiagnosed obstructive CAD (OR 2.30 95% C.I. 1.13–4.69), while mean LDL-cholesterol was inversely associated with absent CAD (0.12, 0.04–0.43). ConclusionsThe prevalence of undiagnosed obstructive CAD was high (24%) in this cohort of long-term survivors with T1D. Mean LDL-cholesterol and HbA1c were associated with CAD.

Cardiac assessment within 5 years of lymphoma treatment can detect patients with high risk of cardiotoxicity and undiagnosed coronary artery disease.

e19562Background: Cardiotoxicity afflicts 10-20% of cancer survivors thus compromising long term survival. Based on ASCO guidelines cancer patients (pts) are considered at increased risk of develop...

Correlation between immunological-inflammatory markers and endothelial disfunction in the early stage of coronary heart disease

Classical risk factors for endothelial dysfunction (ED), such as age, gender, total cholesterol, high-density lipoprotein cholesterol, systolic blood pressure, and smoking history are utilised for the Framingham score and Systemic Coronary Risk Estimation (SCORE) for evaluation of the 10-year cardiovascular risk in routine practice. Nonetheless, pro-inflammatory mediators are deeply involved in the initiation and the progression of ED and coronary artery disease (CAD), and act additionally or independently of metabolic factors before clinical manifestations of the disease appear. C-reactive protein, a marker of intimal thickening of the myeloid-related protein 8/14 heterodimer, monocyte chemotactic protein 1, interleukin-15, the cytotoxic mediator, granulysin, and the matrix metalloproteinase 9 could be valuable, single, fast, and non-invasive laboratory tools for ED deterioration degree assessment. We propose to investigate the impact of pro-inflammatory biomarkers on ED, measured by previously established clinical methods in patients with yet undiagnosed CAD and at medium risk for an acute coronary event. It could be useful to measure and correlate the concentration of particular inflammatory markers in peripheral blood samples and the results of the Framingham and SCORE charts, multi-slice computed tomography coronary angiography, echocardiography, brachial artery flow-mediated dilatation, carotid-femoral pulse wave velocity, ankle-brachial index, carotid wall thickening, myocardial perfusion scintigraphy, and particularly, cardiac magnetic resonance imaging. The goal would be that the degree of correlation between particular inflammatory markers and the results of some methods for the assessment of ED or cardiac ischaemic imaging could be emphasised and pro-inflammatory markers positioned in the pathogenetic algorithm of CAD.

Clinical Features and Prognosis of Type 2 Myocardial Infarction in Acutely Decompensated Diabetic Patients

BackgroundAfter the introduction of the universal definition of myocardial infarction, the incidence and diagnosis of type 2 myocardial infarction have risen dramatically, yet there are no clear guidelines on clinical management. Diabetic patients are at high risk for developing type 2 myocardial infarction when admitted in a decompensated state, and they are also at high risk for future cardiovascular events. MethodsWe performed a retrospective analysis of 1058 patients admitted with diabetic ketoacidosis or hyperosmolar hyperglycemic state between 2011 and 2016. Patients were included if they had cardiac troponin I measured within 24 hours of admission, were older than 18 years of age, and had no evidence of acute coronary syndrome on admission. Baseline characteristics, admission laboratory test results, major adverse cardiovascular events, cardiac stress testing, and coronary angiography data up to 1 year after admission were reviewed. Patients were categorized into 2 groups: those with and those without type 2 myocardial infarction. The study had 2 endpoints: mortality and major adverse cardiac events (MACE) at 1 year and an abnormal result on stress test or coronary angiography at 1 year. ResultsOf the 845 patients who met the inclusion criteria, 133 patients (15%) had type 2 myocardial infarction on admission. Patients with type 2 myocardial infarction were at a significantly higher risk for mortality and MACE at 1 year than those without. Patients with type 2 myocardial infarction were also at higher risk for developing an abnormal result on stress test or coronary angiography within 1 year of admission as compared with those without type 2 myocardial infarction (40% vs 24%; odds ratio 2; P = .0699). ConclusionAcutely decompensated diabetic patients with type 2 myocardial infarction are at increased risk for death and MACE. These patients may also be at risk for undiagnosed coronary artery disease.

Automated characterization of coronary artery disease, myocardial infarction, and congestive heart failure using contourlet and shearlet transforms of electrocardiogram signal

Undiagnosed coronary artery disease (CAD) progresses rapidly and leads to myocardial infarction (MI) by reducing the blood flow to the cardiac muscles. Timely diagnosis of MI and its location is significant, else, it expands and may impair the left ventricular (LV) function. Thus, if CAD and MI are not picked up by electrocardiogram (ECG) during diagnostic test, it can lead to congestive heart failure (CHF). Therefore, in this paper, the characterization of three cardiac abnormalities namely, CAD, MI and CHF are compared. Performance of novel algorithms is based on contourlet and shearlet transformations of the ECG signals. Continuous wavelet transform (CWT) is performed on normal, CAD, MI and CHF ECG beat to obtain scalograms. Subsequently, contourlet and shearlet transformations are applied on the scalograms to obtain the respective coefficients. Entropies, first and second order statistical features namely, mean (Mni), min (Mini), max (Mxi), standard deviation (Dsti), average power (Pavgi), inter-quartile range (IQRi), Shannon entropy (Eshi), mean Tsallis entropy (Emtsi), kurtosis (Kuri), mean absolute deviation (MADi), and mean energy (Ωmi), are extracted from each contourlet and shearlet coefficients. Only significant features are selected using improved binary particle swarm optimization (IBPSO) feature selection method. Selected features are ranked using analysis of variance (ANOVA) and relieff techniques. The highly ranked features are subjected to decision tree (DT) and K-nearest neighbor (KNN) classifiers. Proposed method has achieved accuracy, sensitivity and specificity of (i) 99.55%, 99.93% and 99.24% using contourlet transform, and (ii) 99.01%, 99.82% and 98.75% using shearlet transform. Among the two proposed techniques, contourlet transform method performed marginally better than shearlet transform technique in classifying the four classes. The proposed CWT combined with contourlet-based technique can be implemented in hospitals to speed up the diagnosis of three different cardiac abnormalities using a single ECG test. This technique, minimizes the unnecessary diagnostic tests required to confirm the diagnosis.

Side Effects of CV Medications Following Hospitalization for ACS Are Associated With More Frequent Health-Care Contacts.

Patients hospitalized for first acute coronary syndrome (ACS) are frequently discharged on multiple new medications. The short-term tolerability of these medications is unknown. This single-center cohort study assessed 30-day health-care utilization and how it may be impacted by medication prescribing trends. We included Olmsted County patients presenting with ACS and previously undiagnosed coronary artery disease in 2008 to 2009. All health-care contacts were reviewed 30 days after index hospital discharge for potential adverse medication effects including documented hypotension or bradycardia, or symptoms likely attributed to the medications. The study included 86 patients; their mean age was 63 (standard deviation: 15.5 years). Antianginal or antihypertensive cardiovascular (CV) medications were prescribed to 98% of patients at discharge; 76% were prescribed 2 or more. There were 233 health-care contacts in 30 days; 90 (39%) of these contacts were unscheduled. More CV medications tended to be prescribed to patients with unscheduled contacts, both pre-ACS ( P = .045) and upon hospital discharge ( P = .051). Hypotension and/or bradycardia at follow-up occurred in 52 patients (60%). Surprisingly, there was no association between hypotension and/or bradycardia at follow-up and increased health-care utilization ( P = .12). Potential adverse drug effects were reported in 34 (40%) patients. These patients had significantly more total health-care contacts ( P < .001) and unscheduled health-care contacts (median 0 vs 1.5; P < .001). Symptoms of adverse drug effects were associated with more frequent health-care utilization after ACS. Clinicians need to consider this while striving to increase patient compliance with post-ACS medications and optimize care transitions.

Cardiac risk assessment before non-cardiac surgery

Cardiovascular events account for half of the deaths related to non-cardiac surgery. Identification of a patient's risk and perioperative management appropriate to that risk is important to optimize the clinical outcome of surgery. Key concepts of preoperative cardiac risk assessment are contained within American and European guidelines. Risk indices stratify patients according to clinical and surgery-specific predictors. The most widely used is the Lee index; however, all have limitations. Patients at intermediate and high risk following risk index stratification and assessment of functional capacity require further non-invasive assessment to detect myocardial ischaemia using, for instance, exercise electrocardiography, myocardial perfusion scintigraphy, or stress echocardiography. It can be difficult, however, to decide which technique and predictor is most effective and local practice differs. Invasive coronary angiography is not recommended unless it would be performed in the absence of surgery. Appropriate pain management should be considered in all patients and beta-blockade may improve the outcome in intermediate- and high-risk patients. Identifying patients with risk factors or previously undiagnosed coronary artery disease enables the preoperative cardiac risk assessment to guide long-term treatment.

Screening for Coronary Artery Disease in Type 2 Diabetes

Sensitive tools are available to diagnose occult ischemic and atherosclerotic coronary disease, yet screening for coronary artery disease (CAD) has not been shown to reduce cardiac events in patients with type 2 diabetes mellitus (T2DM). Professional guidelines are inconsistent regarding CAD screening recommendations, but it is suggested that those at highest risk (10-yr risk ≥20%) for cardiac events may benefit. We reviewed bibliographies of professional CAD screening guidelines, review articles, and clinical trials published within the last 10 yr, although we have included relevant older studies. We excluded studies that did not focus on T2DM or explicitly analyze that subgroup. Although screening for coronary ischemia or atherosclerosis does provide incremental prognostic information in patients with T2DM and previously undiagnosed CAD, this has not been found to significantly impact outcomes. This appears to result from comparable efficacy of revascularization and optimal medical therapy in stable CAD. Limited evidence supports the hypothesis that those with more severe CAD (three-vessel, left main, proximal left anterior descending) amenable to bypass surgery may be potential beneficiaries of screening. However, the low prevalence of such candidates in the asymptomatic population, continuing advances with percutaneous intervention, and the lack of prospective trials makes such a recommendation currently unsupportable. Findings to date do not support widespread screening for CAD in patients with T2DM. A future strategy identifying those at highest risk as screening candidates may ultimately be effective, but the optimal method for selecting those subjects or subsequent treatment is unknown.

Background and rationale for mechanism of action, efficacy, and safety of fingolimod (Gilenya), the first oral therapy for remitting-relapsing multiple sclerosis

Background and rationale for mechanism of action, efficacy, and safety of fingolimod (Gilenya), the first oral therapy for remitting-relapsing multiple sclerosis

Low-risk Young Adult Patients With Chest Pain May Not Benefit From Routine Cardiac Stress Testing

Low-risk emergency department (ED) chest pain patients with a nondiagnostic electrocardiogram (ECG) and negative cardiac biomarkers are commonly evaluated with cardiac stress testing to detect undiagnosed coronary artery disease. Provocative testing incurs certain costs and may require additional time investment either in the ED or in an observation setting. Recent research has questioned the utility of provocative testing in young adults with negative cardiac biomarkers and nondiagnostic ECG. We sought to evaluate the utility of cardiac stress testing in our population of young adult patients with chest pain. We performed a retrospective chart review of all chest pain patients aged 40 years and younger who were admitted to our ED observation unit over the 14-month period between April 2006 and May 2007. We included all patients who were admitted to the observation unit for serial biomarkers and provocative testing and had normal or nondiagnostic ECG, no history of coronary disease, and an initial negative troponin. We recorded baseline characteristics and stress test results of these patients and reviewed the patient charts for the 30-day period following discharge to identify repeat hospital visits and adverse events. We used Bayesian analysis to estimate the rate of true-positive stress testing in this population, using the only prior study of unit patients showing as high as 2 of 220 patients testing positive as a prior estimate. A total of 36 patients met inclusion criteria; average age was 34.6 years old (range: 22-40 years) and 61% were male. Patient risk factors included hypertension (19%), diabetes (6%), family history (42%), and smoking (44%). All patients had negative serial cardiac biomarkers and a negative treadmill stress echocardiogram. Thirty-day follow-up demonstrated no adverse cardiac events. We performed Bayesian analysis through the addition of the 36 patients to the 220 patients represented by prior data. The posterior probability distribution changed slightly in location and scale gave a median estimated rate of positive stress testing in this population of 1.04% (95% credible interval, 0.24%-2.78%). The population of chest pain patients younger than 40 years with no history of coronary disease, a nondiagnostic ECG, and negative serial biomarkers may not benefit from provocative testing. Our findings complement those reported previously on the limited utility of cardiac stress testing in this population.

Coronary Artery Disease in a Young USAF Pilot: Screening for Premature Artherosclerosis

Clinically significant coronary artery disease (CAD) in military and civilian pilots may result in disasterous consequences. Pilots with undiagnosed CAD occasionally suffer acute coronary syndrome (ACS) inflight. In single-pilot operations, ACS often ends in crew and passenger fatality. Current standards for assessing the presence of CAD are inadequate. In other nations, additional modalities are used to assess pilots for CAD. A 38-year-old F-16 pilot with no cardiac risk factors presents with chest pain following an 8-hour flight. Angiogram reveals significant single lesion stenosis. The pilot undergoes coronary artery bypass graft. Significant CAD is present in a very small minority of young pilots and more so in older pilots and those with cardiac risk factors. Exercise treadmill test (ETT) followed by multislice computed tomography (MSCT), in lieu of coronary angiography, is highly sensitive and specific in the diagnosis of CAD. MSCT has been implemented by the German Air Force with good results.

191: Low-Risk Young Adult Patients With Chest Pain May Not Benefit From Routine Cardiac Stress Testing: A Bayesian Analysis

Low risk emergency department chest pain patients with a non-diagnostic ECG and negative cardiac biomarkers are commonly evaluated with cardiac stress testing to detect undiagnosed coronary artery disease. Provocative testing incurs certain costs and may require additional time investment either in the emergency department or in an observation setting. Recent research has questioned the utility of provocative testing in young adults with negative cardiac biomarkers and non-diagnostic EKG. We sought to evaluate the utility of cardiac stress testing in our population of young adult patients with chest pain.