Instinct Guides ER Docs Treating Heart Patients

Instinct probably guides the average ER doctor when treating more than just the heart patients but there is no documented evidence to clarify this theory. There is, however, documented evidence that instinct must be driving many of the calls to admit ordered by emergency department (ED) doctors when faced with a patient reporting chest pain.

Chest pain is one of the most frequently voiced complaints in the ED at Wake Forest University Baptist Medical Center, where Chadwick Miller, MD, led a research team to analyze physician responses to patients presenting with the possibility of heart attack (myocardial infarction). Miller is an assistant professor of emergency medicine at the medical center.

Heart attack patients were categorized in one of three groups, based on diagnosis at the time of admission:

No MI: No Myocardial Infarction. Patient came to the hospital with symptoms of heart attack but troponin levels were normal
EMI: Evolving Myocardial Infarction. Symptoms present but troponin levels not elevated. Troponin levels do become elevated later, showing evidence of heart attack, but may not begin rising until 12 hours after initial examination
NSTEMI: Non-ST segment Elevation Myocardial Infarction. Troponin levels elevated upon initial exam, evidence that a heart attack occurred in the very recent past, anywhere from a few hours to a few days before the patient was examined in the ED.

The blood’s concentration of troponin increases when the heart muscle is damaged during a heart attack.

Although they appear identical upon first examination, No MI and EMI diagnoses require different treatment strategies, with the best outcome a result of the quickest action. One sure way to diagnose EMI is with two troponin tests taken within a 12-hour time span but waiting that long to initiate preventive measures is too long. The study revealed that an initial diagnosis of EMI meant the patient received more immediate, aggressive care in triage than the No MI patients.

The question is if a doctor can discern the differences and send the No MI patient home to recover or have the EMI patient hospitalized immediately so preventive measures can begin at once. And, if the answer to that question is yes, ED doctors can tell the difference between the two, the next question is how do they do it?

Miller’s team studied records of 17,000 patients enrolled in a medical registry called i*trACS. Of the entire enrollment group, only 4,136 of the registered patients had gotten two troponin tests within 12 hours. Everyone else who got troponin levels tested, either once or on a different schedule, was eliminated from analysis. Also excluded were children younger than 18 and pregnant women.

How did the doctors fare? Upon initial impression, the patients were diagnosed as follows:

No MI: These patients were considered at 52% increased risk of heart attack than someone showing no symptoms of heart attack
EMI: 76% greater risk of heart attack
NSTEMI: 71% greater risk

Miller says his team’s analysis revealed an encouraging pattern of vigorous treatment when EMI was diagnosed, even though troponin levels were not elevated at the time of evaluation. By attributing EMI to the greatest risk of heart attack, even when laboratory evidence indicated otherwise, Miller feels it is definitely a matter of instinct, not technology, saving lives in EDs every day.

The Emergency Medicine Journal carries full details of the Miller study in its July 24 edition.

Schering-Plough Pharmaceuticals and Millenium Pharmaceuticals awarded an educational grant to support the operation of the i*trACS registry.

Source: Wake Forest University Baptist Medical Center

Filed under: Heart Disease, Medical Research