11-13-2018: Review this post first: Determining Low Risk Chest Pain Using The Modified Heart Score From Emergency Medicine Cases #64
Posted on March 27, 2016 by Tom Wade MD
Recently, I posted My Minicourse Review of The Evaluation Of Chest Pain For Primary Care Clinicians
Posted on October 31, 2018 by Tom Wade MD
The post is outstanding and has information not in my minicourse post.
Here are excerpts from 10 Opportunities For Reducing Missed MIs:
The RVQP’s [The Emergency Department Return Visit Quality Program (RVQP) 2017 evaluation [report] [Link is to the report PDF] included 175 cases of AMI, of which 85 (49%) resulted in the identification of a quality issue/adverse event as judged by the staff of the facility where the care was provided. These included general themes and AMI–related themes—including education about high-risk patient profiles, protocols for repeating troponins, follow-up protocols, and education and follow-up for patients who leave against medical advice (LAMA). The report on the program’s second year has just been released and explores in greater detail the program’s three sentinel diagnoses (revisits due to AMI, subarachnoid hemorrhage, and sepsis in children following initial visits due to chest pain, headache, and fever or flu-like illness, respectively) and how hospitals are learning from return visits to promote QI.
1. Strategies to minimize Leaving Without Being Seen (LWBS) and Leaving Against Medical Advice (LAMA)
2. Triage ECG protocol including patients with epigastric discomfort
When a patient presents to the ED with chest pain it is standard protocol for a nurse or ECG technician to perform an ECG and in many cases to draw blood to assess troponin levels. But with the recognition of “atypical” presentations of AMI, especially epigastric pain, some EDs are expanding their medical directives for ECGs to include certain patients with epigastric discomfort (e.g., older patients, those with risk factors).
3. Physician education on atypical presentations and electronic reminders for high risk patients
AMI has classically been described as exertional chest pressure, and cases that don’t conform to this have been labelled “atypical.” But there is a growing literature questioning this false dichotomy.
Large studies have found that one-third of AMI patients experience no chest pain and one in 20 has atypical pain (e.g., pleuritic or reproducible).[6,7]*
So-called atypical AMI is neither rare nor benign; because AMI without chest pain is more common with age and with comorbidities such as diabetes and congestive heart failure, and because of delays in recognition and treatment, it carries a higher mortality rate.*
Women have often been described as presenting with atypical symptoms because they are more likely to experience non-chest pain AMI symptoms such as shortness of breath, fatigue, weakness, dizziness, epigastric pain/nausea, or muscle aches—and this likelihood rises and converges among men and women with age.As a consequence, some EDs are implementing serial ECG protocols to detect dynamic changes, while others are organizing educational opportunities to improve physician interpretation skills. *
* Emphasis added
4. Serial ECG protocol and physician education in ECG interpretation
The ECG is central to the diagnosis of AMI, but it is only a brief snapshot of a dynamic process of ischemia. For this reason the initial ECG is diagnostic only in slightly more than half of AMI cases, making serial ECGs essential. Even if ECGs detect ischemia, they must be properly interpreted—and a significant number of patients discharged from the ED with AMI have abnormal ECGs in retrospect.[11,12]
The RVQP reflects the literature, with a number of cases having only one ECG performed and a few having new abnormalities identified in retrospect—including mild ST elevation, ST depression, inverted T waves, and Wellen’s sign.*
Wellens syndrome is a pattern of deeply inverted or biphasic T waves in V2-3, which is highly specific for a critical stenosis of the left anterior descending artery (LAD).
Patients may be pain free by the time the ECG is taken and have normally or minimally elevated cardiac enzymes; however, they are at extremely high risk for extensive anterior wall MI within the next few days to weeks.
Due to the critical LAD stenosis, these patients usually require invasive therapy; do poorly with medical management; and may suffer MI or cardiac arrest if inappropriately stress tested.
Rhinehart et al (2002) describe the following diagnostic criteria for Wellens syndrome:
- Deeply-inverted or biphasic T waves in V2-3 (may extend to V1-6)
- Isoelectric or minimally-elevated ST segment (< 1mm)
- No precordial Q waves
- Preserved precordial R wave progression
- Recent history of angina
- ECG pattern present in pain-free state
- Normal or slightly elevated serum cardiac markers
5. Repeat troponin protocol including troponins that rise but remain below the diagnostic threshold for AMI
Troponin is also central in the diagnosis of AMI, and like the ECG it is a dynamic marker that can change over time. A number of chart reviews identified the lack of a repeat troponin measurement, and a couple identified challenges in interpreting levels that were rising but remained within the normal range. Some EDs are developing protocols for repeat troponin measurement, while others are revisiting their protocols to include troponins that rise but remain below the diagnostic threshold for AMI.
6. HEART Score protocol to risk stratify patients for disposition decisions
After a non-diagnostic ECG and negative troponin, most patients presenting with possible AMI are discharged from the ED—some with follow-up in outpatient cardiology clinics. But this practice can miss some patients with unstable angina who are at high risk of AMI and would benefit from expedited tests and inpatient monitoring and management. There are numerous risk stratification tools such as the HEART Score  (recently validated in a Canadian ED ), which helps stratify patients with chest pain into those at low risk who can safely be discharged and those at moderate or high-risk who would benefit from inpatient consultation.
Similarly, this chart review identified a number of sentinel cases of unstable angina with a moderate or high HEART Score who may have benefited from admission on the index visit. As a result, some EDs are standardizing the HEART Score to risk stratify patients into inpatient or outpatient follow-up.
See Resource (2) below about using the Modified Heart Score.
(2) Determining Low Risk Chest Pain Using The Modified Heart Score From Emergency Medicine Cases #64
Posted on March 27, 2016 by Tom Wade MD
(3) Backus BE, Six AJ, Kelder JC, Bosschaert MA, Mast EG, Mosterd A, et al. A prospective validation of the HEART score for chest pain patients at the emergency department [PubMed Abstract] [Full Text HTML] [Full Text PDF]. Int J Cardiol. 2013;168(3):2153-2158.
(4) Andruchow J, McRae A, Abedin T, Wang D, Innes G, Lang E. Validation of the HEART score in Canadian emergency department chest pain patients using a high-sensitivity troponin T assay [Abstract]. CJEM. 2017;19(S1):S61-S62.