Approach to The Low Risk Chest Pain

PatientJohn P Erwin, III, MD, FACC, FAHA

Associate Professor of MedicineScott and White Heart and Vascular

InstituteTexas A&M College of Medicine

Background• 8 million ED visits annually

– At least three times that many presenting to ambulatory clinics

– Only a minority of these patients have a life-threatening condition

• Failure to detect acute coronary syndrome (ACS) and inadvertent discharge of such patients from the ED may exceed 2%– Risk adjusted mortality ratio that is nearly 2-fold that

of patients hospitalized for ACS– Associated with substantial liability

Goals

• Accurate risk stratification• Find the appropriate modality of evaluation

for the circumstance• Patient reassurance• Appropriate utilization of resources• Stay out of court!

Life isn't like a box of chocolates.

It's more like a jar of jalapenos.

What you do today, might burn your butt tomorrow.

NON-CARDIAC DIAGNOSIS

Most Common Non-Cardiac Etiologies of Chest Pain

• Aortic Dissection• Pericarditis• Lung diseases (Don’t miss PTX and PE)• Musculo-skeletal (including cervical and

thoracic disc herniation)• Esophageal (even with normal manometry

studies)• Upper abdominal disease• Psycho-somatic• Functional

See ACC/AHA Guidelines for Chronic Stable Angina

Criteria for Hospital Admission for Chronic Angina

• Worsening ("crescendo") angina attacks

• Sudden-onset angina at rest• Angina lasting more than 15 minutes

Symptoms of unstable angina

See ACC/AHA Guidelines for NSTEMI ACS

See ACC/AHA Guidelines for STEMI

POSSIBLE ACS

1.Immediate ECG

2. Observe

3. Study

Likelihood That Signs and Symptoms Represent an ACS

Secondary to CAD

Likelihood That Signs and Symptoms Represent an ACS

Secondary to CAD

Likelihood That Signs and Symptoms Represent an ACS

Secondary to CAD

1.Immediate ECG

2. Observe

3. Study

1.Immediate ECG

2. Observe

3. Study

RISK SCORES

SIMPLE!!IS THE TROPONIN

ELEVATED (ecg abnormal)?

ED triage of patients with acute chest pain by means of rapid testing for cardiac

troponin I Protocol:• Chest pain less than 12 hours duration

and no STE or new LBBB on ECG• CKMB and TnI within 15 minutes of

evaluation and 4 hours later (or at least 6 hours from onset of chest pain)

Findings:• The overall event rate for patients with

negative troponin I = 0.3%.

NEJM. 337:1648-53. December 4, 1997.

Chest Pain Evaluation Units

Chest pain units manage patients at low risk for myocardial infarction:

1. As effectively as inpatient admission

2. At less cost. West J Med. 2000 December; 173(6): 403–407.

Chest Pain Evaluation Units

• Randomized controlled trial comparing patient satisfaction between those admitted to a chest pain observation unit and controls admitted for routine care – The chest pain unit scored higher than

inpatient management on all 7 satisfaction indices

– Attainment of a statistically significant difference in 4 of these scores.

Ann Emerg Med 1997;29: 109-115.

Exercise Stress Testing in Accelerated Diagnostic Protocols (ADP’s)

Rest Myocardial Pefusion Imaging

Stress Echo

Coronary Calcium ScoringIn patients presenting to the ED with undifferentiated

chest pain, a zero CAC score has been associated with:– a negative predictive value approaching 100%

for early adverse events – This prognostic value was maintained on follow-up

of 4 years. – High sensitivity, low positive predictive value

• often entails additional evaluation. – Increasing CAC is associated with advancing age

and male sex. J Am Coll Cardiol. 2009;53:1642–1650.

Ann Emerg Med. 2010;56:220 –229.

Coronary CT Angiogram(CCTA)

• Provides anatomic rather than functional information regarding coronary patency and produces a noninvasive coronary angiogram.

• In a series of 103 patients presenting to the ED with chest pain, CTCA revealed:– Normal vessels or non-obstructive CAD

(negative predictive value 100%)– None of the patients discharged from the ED

had a major adverse cardiovascular event at 5 months.

Follow-up After Negative Evaluations

• Reconsider the possibility of non-cardiac chest pain etiologies

• In up to 40% of these patients, panic attack or somatoform disorders may be the causative factors

• False negatives are low, but re-take history and address CV risk factors

• Recidivism is high– Still may be a role for angiography (invasive vs CT)

References

• See articles provided for your handouts• Guidelines can all be found and

downloaded at acc.org

Conclusion• Low risk chest pain is the most common

category of chest pain syndromes that primary care providers encounter on a daily basis

• Develop a consistent algorithm of work-up founded upon a thorough H&P

• Good technology available to help us further risk stratify

• If negative work-up for CV cause , treat CV risk factors and address the non-cardiac etiologies of chest pain to help reduce recidivism

An anxious heart weighs a man down,but a kind word cheers him up. --Proverbs 12:25