Efficient Evaluation of Chest Pain Vikranth Gongidi, DO FACC FACOI Indian River Medical Center Vero Beach, FL No Disclosures
Outline Background Chest pain pathway Indications for stress test Stress test modalities
Background 8-10 million patients present to ED in US Annual cost $10-13 billion <10% ultimately diagnosed with Acute Coronary Syndrome Low risk patients (<2% ACS rate) objective cardiac testing is associated with substantial number of falsepositive and non-diagnostic test which leads to invasive testing
Chest pain pathway Develop a path for chest pain evaluation that is efficient and evidence based Various model exist for risk assessment (TIMI, GRACE etc) Most scores are focused on recognising high-risk patients in hospitalised population
Chest pain pathway Risk assessment tools: PURSUIT GRACE TIMI HEART
Risk assessment tools PURSUIT Outdated Designed before the introduction of troponin measurements for clinical use Circulation. 2000;101:2557-2567
Risk assessment tools GRACE Advantage: Based on large population Disadvantage: Calculated with use of a computer, Age affects the score Arch Intern Med. 2003;163:2345-2353
Risk assessment tools TIMI Only binary scores Ignores gray area Even at the lowest score 0 or 1 risk of adverse event is 2.9-4.7% JAMA. 2000;284:835-842
Risk assessment tools HEART Objective info Easy to use (especially in low risk patients) Only one that takes history into account Critical Pathways in Cardiology Vol 9, Num 3, Sept 2010
HEART Score Critical Pathways in Cardiology Vol 9, Num 3, Sept 2010
HEART Score Risk Factors Currently treated DM Current or recent (<90days) smoker Diagnosed/Treated HTN Hypercholesterolemia Family history of CAD Obesity BMI >30 History of atherosclerotic disease Coronary Revascularization Myocardial Infarction Stroke Peripheral Arterial disease Critical Pathways in Cardiology Vol 9, Num 3, Sept 2010
HEART Pathway Combines Heart Score 0 and 3 hour cardiac troponin test Low risk patients discharged from ED
HEART score / Pathways Compared with usual care, use of the HEART Pathway decreased objective cardiac testing at 30 days by 12.1% (P=0.048) and length of stay by 12 hours ( P=0.013) and increased early discharges by 21.3% (P<0.001). No patients identified for early discharge had major adverse cardiac events within 30 days 1 Mahler A et al., The HEART Pathway Randomized Trial: Identifying Emergency Department Patients With Acute Chest Pain for Early Discharge Simon Gregory B. Russell, Circ Cardiovasc Qual Outcomes. 2015;8:2 195-203
Indication for stress test Suspect angina (intermediate to high risk) Acute chest pain Recent ACS (treated conservatively or incomplete revascularization within 3months) Known CAD (new or worsening symptoms) Asymptomatic CABG (>5yrs); PCI (>2yrs) New heart failure or cardiomyopathy New arrhythmia (CBH, Long QT, channelopathies) Non-cardiac surgery (non-emergent)
J Am Coll Cardiol. 2014;63(4):380-406
J Am Coll Cardiol. 2014;63(4):380-406
Stress test modalities Exercise Stress Test (ETT) Stress Echocardiogram Treadmill or Dobutamine Stress Myocardial Perfusion Imaging (MPI) Treadmill, Dobutamine or Pharmacologic Cardiac CTA
Stress test selection factors: 1.) Patient selection and condition is paramount 2.) Availability and ease of test in your facility 3.) Time and cost
Stress test modalities Exercise Treadmill Test Patient selection: 1. Must be able to walk/exercise 2. No significant baseline EKG changes (LBBB,WPW) Sensitivity 68% Specificity 77%
Stress test modalities: ETT Advantage Widely available, Quick to perform, NPO ~1-2hours before test, exercise capacity Disadvantage Patient must be able to follow directions and walk Lower accuracy 73%, Can not localize ischemia to particular area (territory/artery) Can not evaluate LV function Sensitivity and specificity decreases if exercise is submaximal Time/Cost Can be done in one day, usually <30min
Stress test modalities Stress echocardiogram (Exercise or Dobutamine) Patient selection: 1.) Can be done on almost anyone (especially non-walkers or COPD) Sensitivity 81-85% Specificity 79-81%
Stress Echo Advantage Higher sensitivity and specificity than ETT Higher accuracy 84% Quicker test than Nuclear Stress Can evaluate LV function Can localize wall motion abnormalities (and particular artery) Can convert an exercise to pharmacologic stress easily with some delay Disadvantage Patient selection is very important Poor images in very obese patient, large barrel chest Patient cooperation to hold breath and move quickly from treadmill to bed Very Tech dependent Must be able to obtain images within one minute Interpreting physician dependent Time/Cost Can be done in one day, usually 45min - 1hours
Stress test modalities Stress MPI (Exercise, Dobutamine or Pharmacologic) Patient selection 1.) Can be done on anyone 2.) LBBB should have adenosine/regadenoson due to false positive test with exercise Sensitivity 88-90% Specificity 72-82%
Stress MPI (Exercise, Dobutamine or Pharmacologic) Advantage Can be done on almost anyone Higher sensitivity and specificity than ETT Higher accuracy Localize ischemia and ischemia burden Identify infarct (size and local) Can evaluate LV function Disadvantage Relatively expensive Exposure to radiation Body habitus can create artifact Large breast > Anterior defect Large abdomen > Inferior defect NPO for 4-6hours before test If adenosine or regadenoson (Lexiscan) used, no caffeine for 24 hours Time/Cost Can be done in one day (if radio tracer is available and patient is NPO) but usually requires two day stay One day protocols usually take approx < 3hours.
Stress test modalities Cardiac CTA Patient selection 1.) Able to lay down flat on CT table No claustrophobia issues 2.) Requires patient cooperation to hold breath Bring heart rate down to 60 bpm (ideally) Sensitivity 95% Specificity 83%
Cardiac CTA Advantage -Very high sensitivity and specificity -Can identify degree of stenosis and type of plaque (calcified vs soft) -In the intermediate lesions (50-70%), widely used protocols, can not differentiate if the lesion is ischemia inducing Disadvantage -Expensive -Insurance Coverage is highly variable on companies and geographic location -Need to get good heart rate control (ideally 60 bpm or less) -Difficult to perform if there is underlying arrhythmia (atrial fibrillation, freq PAC/ PVC) Image acquisition is based on EKG timing of the R-R interval -Specialized equipment and training necessary -Need at least 64 slice CT -Cardiologist and/or radiologist trained in reading -Radiation exposure -Contrast dye exposure -Need prep if there is contrast allergy -Cautious use in Chronic Kidney Disease patients Time/Cost -Needs to be NPO at least 6 hours -Total time depends on how fast heart control can be achieved
Circulation. 2010;121:2509-2543.
Modality Total Patients Sensitivity Specificity Exercise ECG 24,047 0.68 0.77 Dobutamine echo 2582 0.81 0.79 Treadmill echo 2788 0.85 0.81 Treadmill SPECT Adenosine SPECT 5272 0.88 0.72 2137 0.9 0.82 Coronary CTA 230 0.95 0.83 Gibbons RJ et al. ACC/AHA guidelines update for the management of patients with chronic stable angina. 2002 Budoff MJ et al. JACC 2008; 52: 1724-32
Conclusion: Establish chest pain pathway HEART Pathway Our experience Stress test selection Appropriate to the patient Institutional availability and expertise