LETTERS: Letters to the Editor
The authors respond:
We agree with Dr. Poole1 that the absolute risk of having a myocardial infarction is very low. This point was reflected in the commentary by Dr. Siscovick2 that accompanied our paper3; it has also been considered in other publications about triggers of myocardial infarction.4–6 For example, sexual activity is recognized as a known trigger of myocardial infarction, but, precisely because of the very low absolute risk, and keeping in mind the potential benefits, most people at risk of having a myocardial infarction are not discouraged of having sex.5,7
However, Dr. Poole missed the point of our study, which explored a biologic mechanism. In theory, any exposure that increases the sympathetic nervous system could trigger a myocardial infarction provided that there is a vulnerable atherosclerotic plaque. Caffeine in coffee is a known stimulant of the sympathetic nervous system. Based on this biologic mechanism, we showed not only that coffee may trigger a myocardial infarction (regardless of the low absolute risk) but also that this effect is modified by habitual intake of coffee and physical activity.3 These two modifiers indicate that some habitual lifestyles make people less susceptible to surges in sympathetic activity. In our view, the consistency between the data and the hypothesized biologic mechanism is a major strength of our study.
It was not our intention to alarm people about having a heart attack after a single cup of coffee. We regret that Dr Poole felt apprehensive about having his daily cup of coffee. It is clear that in order to decrease the absolute risk of myocardial infarction one should focus on the traditional known risk factors: no smoking, healthy diet, weight control, and physical activity—and, by all means, enjoy the small pleasures of life!
Department of Community, Health Brown University, Providence, RI firstname.lastname@example.org
Department of Epidemiology, Harvard School of Public Health, Boston, MA
Edmond K. Kabagambe
Department of Epidemiology, School of Public Health, University of Alabama at Birmingham
Centro Centroamericano de Población, Universidad de Costa Rica
Department of Nutrition, Harvard School of Public Health, Boston, MA
1. Poole C. Coffee and myocardial infarction [letter]. Epidemiology
. 2007;18: xx–xx.
2. Siscovick DS. Triggers of clinical coronary heart disease [editorial]. Epidemiology
3. Baylin A, Hernandez-Diaz S, Kabagambe EK, et al. Transient exposure to coffee as a trigger of a first nonfatal myocardial infarction. Epidemiology
4. Moller J, Ahlbom A, Hulting J, et al. Sexual activity as a trigger of myocardial infarction. A case-crossover analysis in the Stockholm Heart Epidemiology Programme (SHEEP). Heart
5. Muller JE. Sexual activity as a trigger for cardiovascular events: what is the risk. Am J Cardiol
6. Muller JE, Mittleman A, Maclure M, et al. Triggering myocardial infarction by sexual activity. Low absolute risk and prevention by regular physical exertion. Determinants of Myocardial Infarction Onset Study Investigators. JAMA
7. DeBusk R, Drory Y, Goldstein I, et al. Management of sexual dysfunction in patients with cardiovascular disease: recommendations of the Princeton Consensus Panel. Am J Cardiol