Modalities of Cardiac Stress Test

1. Modalities of Cardiac Stress Test Tiffany T. Nguyen MD April 2014

2. Objectives • To understand the indications and contraindications for stress testing. • To learn the different modalities of cardiac stress test. • To effectively select the optimal cardiac stress test for each patient.

3. Indications Who to stress? • Symptoms suggesting angina. • Acute chest pain • Recent ACS after 3 months of conservative therapy • Known CHD and change in clinical status. • Prior coronary revascularization. • Valvular heart disease. • New heart failure or cardiomyopathy. • Chronic left ventricular dysfunction and CHD who are candidates for revascularization. • Selected arrhythmias • Undergoing non-urgent non-cardiac surgery.

4. Contraindications Who NOT to stress? • Unstable angina • Acute myocardial infarction • Arrhythmia with hemodynamic instability • Aortic dissection • Symptomatic aortic stenosis • Symptomatic severe heart failure • Pulmonary embolism • Myocarditis, Pericarditis

5. Pre-Test Probability ACC/AHA 2012 Guidelines Lowprobability - <10% - no further testing, except for prognostic information. Intermediateprobability - 10-90% - non-invasive testing for diagnosis (exercise ECG as first modality). Highprobability - >90% - non invasive testing for prognosis/management prior to cardiac cath.

6. Two Components • Each cardiac imaging modality has two components: • Stressing agent: treadmill, dobutamine, or adenosine • Imaging agent: EKG, echo, or radionuclide tracer (thallium or technetium)

7. Stressing Agents

8. Imaging Agents

9. Finally … • What is a “MIBI?” What is a “Lexiscan?” • Both are adenosine nuclear stress tests • MIBI: the technetium molecule is attached to sestamibi molecule. The combined sestamibi-Technitium-99 molecule is aka “cardiolite” • Lexiscan: uses a derivative of adenosine called regadenosine, which has 2-3 minute half-life instead of 30sec, so is easier to work with.

10. Sensitivity and Specificity

11. Selecting Modalities Indication Diagnosis or Prognosis Localize Ischemia Exercise? Exercise? no no yes Pharmacologic test with Imaging yes Normal EKG Not on Digoxin No prior revascularization no Exercise Imaging yes Exercise EKG

12. Case Question A 60yo man is evaluated for chest pain of 4 months’ duration. He describes the pain as sharp, located in the left chest, with no radiation or associated symptoms, that occurred with walking one to two blocks and resolves with rest. Occasionally, the pain improves with continued walking or occurs during the evening hours. He has hypertension. Family history does not include cardiovascular disease in any first-degree relatives. His only medication is amlodipine. On physical examination, he is afebrile, blood pressure is 130/80mHg, pulse rate is 72/min, and respiration rate is 12/min. BMI is 28. No carotid bruits are present, and a normal S1 and S2 with no murmurs are heard. Lung fields are clear, and distal pulses are normal. EKG showed normal sinus rhythm.

13. Case Question • Which of the following is the most appropriate diagnostic test to perform next? • Adenosine nuclear perfusion stress test. • Coronary angiography • Echocardiography • Exercise treadmill

14. Take Home Points • Stress testing is indicated for patients with intermediate pre-test probability • Each stress test has two components: an imaging modality and stress modality • When determining which stress test to order, keep in mind their ability to exercise and whether any contraindications are present