Stress Testing – Outpatient Evaluation for Coronary Artery Disease

Plan to spend at least 30-60 minutes preparing for this talk.  We have not yet created a Learner board so you will need to use the Presenter board to get a gist of the flow for this talk (more on this below). On the PowerPoint, every box with rounded edges and a shadow is an animated button.  You will want to click these to advance through the presentation, rather than just using the arrow keys or scrolling through animations.

This talk can be presented in two ways:

1. Project the “Interactive Board for Presentation”.
or
2. Reproduce a drawing of the presentation on a whiteboard.

With either method, print out copies of the Learner’s Handout so they may follow along during the presentation and take notes as you expand on the decision tree and apply it through the six practice cases. Begin with reviewing the objectives for the session.

Objective 1: One of the most important steps to properly framing this talk is to help learners clarify the clinical question they are attempting to answer.  Click “Clinical Question”.  For outpatients presenting with non-acute chest pain, the provider wants to know if the symptom is due to a flow-limiting coronary lesion (obstructive CAD).  For a patient presenting with acute chest pain to the Emergency Department, the relevant question is if this Acute Coronary Syndrome (ACS) and if the patient will benefit from intensive inpatient management by means of reducing the likelihood of a Major Adverse Cardiac Event (MACE).

Objective 2: Click on “CAD Consortium Score” or “HEART Score” to review and discuss the value of using a clinical scoring system to risk-stratify patients for either of the clinical questions identified by objective 1.  The point to stress here is that these scores are simply a tool that provides a check on our system 1 thinking (intuition).  The scores are not intended to supersede our clinical reasoning and will often misclassify patients.

Objective 3: Click “Diagnosis and Management” to reveal the two talks for the two clinical questions.  This post is exclusively for the outpatient diagnosis of obstructive CAD (stay tuned for the ACS talk).  Click on the flow diagram, which is the focus of this talk.   Risk on this diagram refers to the pre-test probability that the patient has obstructive CAD (clinically relevant CAD).  If the patient is low risk (low pre-test probability), as determined by the CAD Consortium Score, look for alternative explanations.  If the patient is high risk, obtain an ECG and a stress test with imaging.  The purpose of these studies is to rule out high-grade diseases at increased risk for sudden cardiac death, specifically left main or proximal LAD disease.  If there is no evidence of high-grade disease or significant cardiomyopathy, then it is likely appropriate to proceed with medical management and defer a left heart cath (LHC) or coronary CTA till the patient fails medical management.  A patient at intermediate risk (5-70%) warrants stress testing to confirm or rule out obstructive CAD.  The first decision point is if an exercise treadmill test (ETT) is possible.  An ETT is preferred because it is cheap, provides functional information, and allows a provider to assess if the symptom warranting the study is reproducible with exertion.  However, a sufficiently abnormal ECG precludes this option as it will reduce the sensitivity of the test.  Still, if a patient is able to exercise they could still do an exercise stress echo or nuclear (often referred to as myocardial perfusion, nuclear or SPECT) study.  If the patient cannot exercise then pharmacologic stress (echo or nuclear) test is the only option.  Whether a patient receives a stress echo or nuclear study is institutional specific.  Both offer similarly accurate information including ejection fraction.  However, an echo will also assess valve function. If any of these stress tests are positive (but not markedly so) the patient should initiate medical management.  If the test is “markedly positive” or if they fail medical management, then further evaluation of the coronary anatomy with a coronary CTA or LHC is warranted.

Objective 4: The purpose of this portion of the talk is to reinforce the diagnostic pathway of objective 3 and to allow discussion of the nuances to assessing the quality of chess pain.  We purposely provided unclear or incomplete clinical stems to simulate the reality of a common patient's history and to force more discussion.  Ask your learners to work in small teams to review the vignettes, discuss if they believe the chest pain is typical, atypical or non-specific, and determine a risk category (low, intermediate, or high).  Ask them to reflect on how the CAD consortium score compared to their first gestalt assessment.   Then proceed through the clinical data and decision making.  There are no absolutely correct answers here.  Again, this exercise is intended to reinforce the framework and generate discussion of higher-level thinking.

The talk, including cases, will take 40-50 minutes.