Ryan Radecki from EM Lit of Note is here to deconstruct the HEART score, utility of stress tests in low risk patients, and his approach to low risk chest pain. As a bonus, Ryan is also the wordsmith for the show notes.

There is no such thing as “zero-risk” chest pain:

Once you learn to stop worrying and love again, where are we going with “low-risk” chest pain?

Simply put, most of our observation chest pain evaluations represent low-value care:

Step 2: Shared decision-making.
After making a diagnosis regarding acute MI in the Emergency Department – or, at least, to the extent hs-Troponin permits such an answer – outcome prognostication begins.

Most folks are familiar with TIMI for risk-stratification, despite not being derived in the Emergency Department. While it is still a reasonable to assess overall risk with TIMI, most folks are moving to the HEART score, while a few other protocols/algorihtms – EDACS, MACS, Vancouver, modified Goldman – are also vying for use.

There’s a lovely synergy between identifying a patient as “low risk” and the negative predictive value of negative troponin testing in the Emergency Department. Patients discharged with negative – particularly undetectable troponins – will have event rates at a fraction of a percent, and even lower if only AMI or cardiac-death are included. This is why HEART is described, primarily, as a single-troponin strategy.

These are the sorts of numbers to present to patients in the context of shared decision-making as part of changing the routine conversation about admission into one about discharge. Returning autonomy to the patient to make an informed choice about further care – and documenting such – allows the patient to assume the risks of their self-determination. Adding mention of the frequency of false- positives in a low-risk population – roughly as frequent as the true positives – is also valuable.

There are still quirks with HEART – mostly that patients, in theory, can have ischemic EKGs or elevated troponins and still remain “low risk”. These instances ought to be extremely rare in practice – and clinicians will have to make prudent individualized decisions given the clinical context. The fantastic Stephen Smith, of Hennepin County, also frequently reminds me true unstable angina is still an important troponin-negative. These are near-critical occlusions of the coronary circulation, and the key to diagnosis – and missed diagnosis – is correctly interpreting the EKG and performing serial EKGs in the Emergency Department.

Lastly, it is important to note the AHA Guidelines, as well as prudent longitudinal medical care, recommend patients still have follow-up for additional diagnostics or management, as indicated. Patients at low-risk and with negative biomarkers are at profoundly low-risk for events in, at least, the very short term. Of 11,230 patients observed and with negative biomarkers in Ohio community hospitals, only 20 had a potentially preventable poor outcome related to hospitalization. Narrowed down to the 7,266 patients with entirely normal EKGs and vital signs, 4 had poor outcomes – 2 of which were noncardiac, and 2 of which were iatrogenic. Patients, particularly low-risk, are almost certainly safer outside the hospital than in!

Stress Test Utility Citations:
"Safety of a rapid diagnostic protocol with accelerated stress testing" 

“The Association Between Pretest Probability of Coronary Artery Disease and Stress Test Utilization and Outcomes in a Chest Pain Observation Unit” 

“The incremental value of stress testing in patients with acute chest pain beyond serial cardiac troponin testing”

hs-Troponin Citations:
“Multicenter Evaluation of a 0-Hour/1-Hour Algorithm in the Diagnosis of Myocardial Infarction With High-Sensitivity Cardiac Troponin T”

“High-sensitivity cardiac troponin I at presentation in patients with suspected acute coronary syndrome: a cohort study”

“Implications of Introducing High-Sensitivity Cardiac Troponin T Into Clinical Practice”

“Prospective validation of a 1-hour algorithm to rule-out and rule-in acute myocardial infarction using a high-sensitivity cardiac troponin T assay”

“Does undetectable troponin I at presentation using a contemporary sensitive assay rule out myocardial infarction? A cohort study”

“Troponin Elevations Only Detected With a High-sensitivity Assay: Clinical Correlations and Prognostic Significance” 

“High-sensitivity versus conventional troponin for management and prognosis assessment of patients with acute chest pain” 

“Undetectable High Sensitivity Cardiac Troponin T Level in the Emergency Department and Risk of Myocardial Infarction” 

"Validation of High-Sensitivity Troponin I in a 2-Hour Diagnostic Strategy to Assess 30-Day Outcomes in Emergency Department Patients With Possible Acute Coronary Syndrome"

"Early rule out of acute myocardial infarction in ED patients: value of combined high-sensitivity cardiac troponin T and ultrasensitive copeptin assays at admission"

"Increasingly Sensitive Assays for Cardiac Troponins"

“One-hour rule-out and rule-in of acute myocardial infarction using high-sensitivity cardiac troponin T.”

"High-sensitivity troponin T for early rule-out of myocardial infarction in recent onset chest pain"

“Serial changes in highly sensitive troponin I assay and early diagnosis of myocardial infarction.”

HEART Score Citations:
“Identifying Patients Suitable for Discharge After a Single-Presentation High- Sensitivity Troponin Result: A Comparison of Five Established Risk Scores and Two High-Sensitivity Assays”

“The HEART Pathway Randomized Trial – Identifying Emergency Department Patients With Acute Chest Pain for Early Discharge”

“2014 AHA/ACC Guideline for the Management of Patients With Non-ST-Elevation Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines” 

"A prospective validation of the HEART score for chest pain patients at the emergency department"

"Improving risk stratification in patients with chest pain: the Erlanger HEARTS3 score"

Unstable Angina Citations:
“Unstable angina still exists. Beware.” 

“A Case of Clinical Unstable Angina in the ED”

“Unstable Angina: Dr. Braunwald asks if it is time for a Requiem”

Safety of Chest Pain Discharge Citation:

“Risk for Clinically Relevant Adverse Cardiac Events in Patients With Chest Pain at Hospital Admission”