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Chest Pain: New Methods Applied to an Old Problem. Jon W. Wahrenberger, MD January 23, 2003. Chest Pain. 5 Million emergency department visits 2 million hospitalizations annually with cost of more than $8 billion Cardiac etiology found in less than one third
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Chest Pain: New Methods Applied to an Old Problem Jon W. Wahrenberger, MD January 23, 2003
Chest Pain • 5 Million emergency department visits • 2 million hospitalizations annually with cost of more than $8 billion • Cardiac etiology found in less than one third • 2% of patients with acute MI are unrecognized and discharged from the ED
Chest Pain • Rapid Dx &Tx = saved muscle = improved outcome • Largest category of loss from malpractice litigation in the emergency department
Goals • Rapid recognition of management of true ACS • Recognition of other life-threatening causes of chest pain • Aortic dissection • Pulmonary embolism • Tension pneumothorax • Minimize cost and hospitalization in patients with chest pain of benign etiology.
Chest Pain Diagnosis • Clinical diagnosis • Diagnosis using computer algorithms • Chest pain centers
“Classic” Angina • Location: central chest • Quality: squeezing, heaviness • Radiation: arm(s), neck, jaw • Associated symptoms: dyspnea, diaphoresis, nausea • Eliciting factors: exertion • Relieving factors: rest, nitroglycerin
Musculoskeletal Gastrointestinal Cardiac Psychiatric Pulmonary Other/unknown Differential Diagnosis
Coronary Heart Disease Stable angina pectoris Unstable angina Myocardial infarction Coronary Vasomotor Disease Variant angina Microvascular angina Pericarditis Myocarditis Valvular Heart Disease Aortic stenosis Mitral stenosis Hypertrophic cardiomyopathy Aortic Dissection Post-pericardiotomy Cardiovascular Chest Pain
Cardiac or not? • If cardiac, how to manage?
Chest Pain Diagnosis: What are we Seeking? • Pathologic: MI or No MI • Management Based: ST Elevation MI or not? • Prognostic • Anatomic: Correlating with cath findings • Functional: Correlating with ischemia • Detailed Diagnosis
Group 1 MI with ST elevation or new LBBB MI without ST elevation Group 2 Unstable angina-high risk Unstable angina – low risk Non-ischemic chest pain Traditional Classification of Pts with CP
Group 1 MI with ST elevation New LBBB Primary PCI or Thrombolytics Group 2 MI without ST elevation and no LBBB Unstable angina – high risk Heparin, GP IIbIIIa inhibitor Ideal Categorization of Patients with CP Group 3 Unstable angina – low risk Heparin, admission Group 4 Non-cardiac chest pain Discharge or Treat as condition warrants
Clinical Evaluation of Chest Pain:Meta Analysis • Medline search from 1980-1998 • Inclusion Criteria: • Evaluation of pts thought to have cardiac ischemia • Tool: history, PE, ECG • Outcome assessed: MI or no MI • Sample size > 200 patients • Statistical methods: pool studies and determine likelihood ratios Panju, et al. JAMA 1998;280:14:1256-1263
Features Decreasing Likelihood of AMI Panju, et al. JAMA 1998;280:14:1256-1263
ECG Features Increasing Likelihood of MI Panju, et al. JAMA 1998;280:14:1256-1263
Clinical Symptoms and Angiographic Disease • Goal: determine correlation between clinical characteristics and angiographic disease • Population: • 65 of 1022 patients undergoing angiography and with normal coronaries • 65 consecutive age-matched controls and with angiographic CAD (> 70 diameter narrowing) • Method: all patients interviewed within 24 hours of angiogram by interviewers blinded to angio results Reference: Cook, et al. Heart 1997;78:142-6
Clinical Symptoms and Angiographic Disease Results: • No correlation between site of pain, radiation, quality of pain, or relief with NTG and presence of disease • Only four clinical variables separated groups: a. Reproducibility with exercise (10/10 v. 1-9/10) b. Lack of rest symptoms (0-1/10 v. 2-10/10) • Duration of 5 minutes or less (5 min. v > 5 min) • Age (<55 v. ≥55) Reference: Cook, et al. Heart 1997;78:142-6
Clinical Symptoms and Angiographic Disease Reference: Cook, et al. Heart 1997;78:142-6
Clinical Symptoms and MI in Patient with Non-diagnostic ECG Goal: measure ability of clinical features to predict AMI or ACS in those with non-diagnostic ECG Study Population: 893 pts presenting to large teaching hospital in the UK with suspected AMI or ACS. Study Protocol: History, PE, ECG & CXR Baseline CK-MB, Trop T at six hours If enzymes negative, stress test and discharge Reference: Goodacre, et al. Acad. Emerg Med 2002;9:20308
Pain site Radiation Nature Duration Associated symptoms Pleuritic Nature Response to exercise Chest wall tenderness Response to NTG Clinical Symptoms and ACS/MI in Patient with Non-diagnostic ECG • Endpoints: • AMI by WHO criteria • ACS defined by AMI on presentation or w/i 6 mo. Reference: Goodacre, et al. Acad. Emerg Med 2002;9:20308
Clinical Symptoms and ACS/MI in Patient with Non-diagnostic ECG Reference: Goodacre, et al. Acad. Emerg Med 2002;9:20308
Chest Pain: Evaluation Based on Prognosis Prediction of Risk for Patients with Unstable Angina Evidence Report/Technology Assessment No. 31 Agency for Healthcare Research and Quality
AHRQ Meta Analysis • MEDLINE search 1966-1998 of studies performing multivariate analysis of clinical and/or ECG predictors of adverse clinical events in patients with suspected or diagnosed unstable angina. • Separate analysis of predictive value of troponin and Chest Pain Units
AHRQ Meta Analysis Clinical Predictors: • Demographics (age, sex, ethnicity) • Medical history (prior MI, CHF, diabetes, etc) • Symptom Characteristics • Initial Exam findings • Initial ECG features Outcomes: Cardiac death, MI, other major cardiac complications
AHRQ Meta Analysis • Demographic features correlating with poor prognosis: • Increasing age • Male gender • Prior Medical Conditions: • Prior MI • Diabetes • (Prior CHF, HTN, smoking) 1
AHRQ Meta Analysis • Symptom characteristics: not predictors • Initial exam features: • Low BP • CHF • Cardiogenic shock 1
Clinical Diagnosis of Chest Pain • Location, quality of pain generally not predictive of cardiac cause • Response to nitroglycerine not a reliable predictor • While radiation and associated symptoms may be predictive, their sensitivity and specificity are quite low • More than a history and physical are needed!
Chest Pain Diagnosis • Clinical diagnosis • Diagnosis using computer algorithms • Chest pain center
Computer Guided Chest Pain Diagnosis • Goldman Chest Pain Protocol • Acute Coronary Ischemia Time-insensitive Predictive instrument (ACI-TIPI)
Goldman Chest Pain Protocol • Computer derived decision aid • Designed to improve triage to CCU • Initially developed in prospective study of 1379 patients presenting with acute chest pain • “Recursive partitioning” used to divide subjects into subgroups correlating with high or low risk of MI Goldman, et al. N Engl J Med 1982;307:588-96
Goldman Chest Pain Protocol Goldman, et al. N Engl J Med 1982;307:588-96
Goldman Chest Pain Protocol • Validated prospectively in second trial of 4770 patients Goldman et al. N Engl J Med. 1988;318:797-803
Goldman Chest Pain Protocol • Advantages: • Higher specificity than MD • Disadvantages: • Predicts only AMI (not USA) • Never shown to alter: • Hospitalization rate • Length of stay • Cost
ACI-TIPI(Acute coronary ischemia time-insensitive predictive instrument) • Predictive protocol incorporated into electrocardiogram with automatic results • “Time insensitive” so can be used either retro- or prospectively Selker, et al. Ann Intern Med 1998;129: 845-55
Age Sex Presence of absence of chest pain or pressure of left arm pain Chest pain as most important symptom ECG Q waves or not Presence and degree of ST elevation or depression Presence or absence of T-wave elevation or inversion ACI-TIPI: Clinical Variables Selker, et al. Ann Intern Med 1998;129: 845-55
ACI-TIPI • Validated in 3 trials: • UCLA Harbor Medical Center N= 189 • University of Geneva N=605 • ACI-TIPI Trial N= 10,689
ACI-TIPI Trial • Clinical trial at 10 U.S. hospitals • ACI-TIPI protocol installed in all ED electrocardiograph machines • Clinical intervention: 7 alternating months of: • ACI-TIPI probability of ischemia provided • ACI-TIPI probability of ischemia not provided • 10,689 patients enrolled Selker, et al. Ann Intern Med. 1998;129:845-55
ACI-TIPI Trial Results • No difference in 30 day mortality • No difference in in-hospital complications • No difference in re-hospitalization rates
Chest Pain Diagnosis • Clinical diagnosis • Diagnosis using computer algorithms • Chest pain centers
Chest Pain in the Emergency Department • 4.5 million annual ED visits for chest pain • About one fourth have true ACS • Treatments for ACS are time sensitive • About 2-4% of acute MIs are missed in the ED • Number one cause of ED related malpractice • Strong bias for admission
Chest Pain Units • Goal: accurately determine presence or absence of acute myocardial ischemia • Rapid efficient treatment of AMI • Avoid unnecessary hospitalization (and cost) • Avoid inappropriate discharge • Logistics: Often associated with and staffed by Emergency room and include telemetry and resuscitation equipment
Chest Pain Units • Heart attack program • Diagnostic (observational) program to rule out MI • Educational outreach program
Out of hospital ECG Continuous/serial ECG Exercise stress ECG CPK (presentation) CPK (serial) CK-MB (presentation) CK-MB (serial) Myoglobin (presentation) Myoglobin (serial) Troponin I (presentation) Troponin I (serial) Troponin T (presentation) Troponin T (serial) Rest echocardiography Stress echocardiography Sestamibi (rest) ACI-TIPI Goldman Chest Pain Protocol Algorithms/protocols Computer based decision aids Diagnostic Strategies in ACS
University of Cincinnati “Heart ER” Strategy