Source Document: Our Study Analysis Review Spreadsheet
Narrative: Heart disease remains a major cause of death in western industrialized nations and around the world. It is extremely difficult, however, to reliably forecast which patients with vague or 'soft' symptoms like chest pain will go on to have a true heart problem like a heart attack or death.
In particular chest pain occurring without electrocardiogram changes or biomarker (i.e. troponin) abnormalities is one such 'soft' symptom, and represents the great majority of chest pain patients seen by health care providers. Unfortunately a small proportion of the-se patients will suffer a heart attack or even death, but reliably testing and treating these people without over-testing and over-treating everyone else has proved impossible with current technologies and decision aids.
This review examines the highest quality data available from emergency department evaluation of patients under age 40 who do not have classic cardiac pain, nor classic EKG abnormalities, nor initial biomarker abnormalities*, and who do not have a history of known heart problems. When a physician judged a patient unlikely to have a coronary syndrome and the above criteria were present, the chance of a heart attack or death was extremely small: 2 in 2043. These 2043 patients were pooled from 13 studies. In these data there was 1 heart attack and one death that occurred within 30 days of the initial evaluation. The one death occurred in a patient with metastatic cancer, and it was unclear if the death was related to heart disease. For conservative purposes we counted this death as potentially cardiac.
*Cardiac enzymes used in all contributing studies were either conventional assays of cardiac troponin or CK-MB. Studies using only high-sensitivity troponin assays were excluded. All troponin data in these studies is based on the initial troponin only.
Caveats: These data rely on physician judgment which is generally unstructured, and it is likely that there is considerable variation in judgment. The data are from multiple centers though one center disproportionately contributes, and that is an urban emergency department in Philadelphia where chest pain studies are of unusually high quality with complete data collection and excellent 30-day follow-up. This population may exhibit different characteristics than some others, however the sociodemographic profile of this population (low socio-economic status, high minority) would suggest a higher-than-average risk pro-file rather than a diminished risk profile.
Importantly, because there is no evidence that percutaneous coronary intervention is beneficial outside of emergent use during ST-elevation myocardial infarction (major heart attack), and only weak evidence of a long term benefit with bypass surgery, we do not count 'revascularization' as an important outcome.
It is also important to note that there was variation in the clinical criteria used in the con-tributing trials. In other words, the studies included in this analysis did not all use exactly the same criteria that we use in this review article. At every point in the data collection process where there was ambiguity the most conservative option was chosen. For example, some studies did not specify that the treating physician judge the patient as “low risk”—this criterion was added as a conservative measure to support a low false negative rate.
Author: Harvey Pendell Meyers and David Newman, MD
Published/Updated: September 19, 2010
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