Source Document: Hollander JE, et al. Coronary computed tomographic angiography for rapid discharge of low-risk patients with potential acute coronary syndromes. Ann Emerg Med. 2009; 53:295-304. (n=568). Goldstein JA, et al. A randomized controlled trial of multi-slice coronary computed tomography for evaluation of acute chest pain. J Am Coll Cardiol. 2007;49:863-871. Personal communication with J Hollander (n=approx 700 additional subjects using same methods as Reference 1, "Coronary computed tomographic angiography for rapid discharge of low-risk patients with potential acute coronary syndromes").
Narrative: Heart disease remains a major cause of death in western industrialized nations and around the world. Health care providers have traditionally found it difficult to reliably forecast which patients with vague or 'soft' symptoms of possible heart disease will actually have a heart problem. Chest pain that is not reproducible with exertion, and that is not occurring in the setting of electrocardiogram changes that are typical of active heart disease, is one such 'soft' symptom.
It is clear that a small proportion of these patients will suffer a heart attack or even a death, but reliably forecasting these outcomes without over-treating an unacceptable proportion has proved impossible with current technologies and decision aids. This review examines the highest quality data available from emergency department evaluation of patients age 40 and above who do not have classic cardiac pain, nor classic EKG abnormalities. When an emergency physician judged the patient unlikely to have a coronary syndrome and the above criteria were present, the chance of a heart attack or death was extremely small, roughly 1 in 250. In these data there were no cardiovascular deaths that occurred within 30 days of the initial evaluation (there was one death due to motor vehicle accident and one due to other chronic disease), although there were 5 heart attacks (5/1400≅0.4%). All occurred during hospital evaluation after admission for the chest pain.
Caveats: These data rely on physician judgment which is generally unstructured, and it is likely that there is considerable variation in judgment patterns. The data are from multiple centers though one center disproportionately contributes, and that is an urban ED in Philadelphia where chest pain studies are of unusually high quality with uncommonly complete data collection and 30-day follow-up success. 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 profile rather than a diminished risk profile. There are also small numbers of patients <40 who are included in this cohort, though this group is reviewed in a separate NNB review.
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 seems particularly unlikely to us that these interventions could have an impact on short-term, 30-day outcomes. In these data, however, there were 14 revascularization procedures (13 stents and 1 bypass surgery) or roughly 1% of the population. In general, patients who have had 'soft' chest pain, and in whom testing such as coronary angiography or stress testing demonstrates coronary narrowing (a relatively common finding even in asymptomatic persons), were treated as though the coronary narrowing is the cause of their chest pain. This is unlikely to be the case, but the conservative approach of most practitioners is to presume this. Therefore we do not consider revascularization procedures to be either of likely therapeutic benefit, nor of likely relevance to the two important outcomes that patients hope to avoid, death and heart attack.
Author: David Newman, MD
Published/Updated: September 21, 2010
