Correspondence

Chest Pain in Women

N Engl J Med 1996; 335:820-821September 12, 1996

Article

To the Editor:

In their review of coronary artery disease in women, Douglas and Ginsburg (May 16 issue)1 define major, intermediate, and minor determinants of coronary artery disease. They define a high-risk group (with a pretest probability of disease of more than 80 percent) that comprises women with two or more major determinants (typical angina, postmenopausal status without hormone replacement, diabetes mellitus, or peripheral vascular disease) or one major determinant and more than one intermediate or minor determinant. The authors recommend for this group an exercise-tolerance test as the initial test. If the result is positive or inconclusive, they recommend subsequent cardiac catheterization. However, if the exercise test is negative, they recommend careful observation without any subsequent diagnostic test.

This approach does not take into consideration Bayes' theorem. If the pretest probability of coronary artery disease is high, then the post-test probability stays in the intermediate range if the exercise test is negative. Compliance with the recommendation of Douglas and Ginsburg to refrain from further testing in the subgroup of postmenopausal women without hormone replacement who have typical angina could result in a low negative predictive value for coronary artery disease, delaying the diagnosis and treatment of patients. Patterson and Horowitz have demonstrated a pretest probability of coronary artery disease of 80 percent in middle-aged women with typical angina.2 In older women, this probability is higher. In this group, a negative exercise-tolerance test reduces the post-test probability to 47 percent. Pooled data from the literature shows that in middle-aged patients who have typical angina (with a pretest probability of coronary artery disease of 85 percent), the post-test probability is 60 percent when the exercise test is negative.3 When the exercise thallium scan is also negative, the post-test probability of coronary artery disease is 30 percent. Two recent studies have demonstrated similar levels of accuracy of exercise testing and thallium perfusion scanning in men and women.4,5

Hence, both middle-aged or older men and women who have typical angina and have negative exercise tests should undergo exercise perfusion scans.

Ilan Auerbach, M.D.
Pierre Chouraqui, M.D.
Michael Motro, M.D.
Chaim Sheba Medical Center, Tel Hashomer 52621, Israel

5 References

1. 1

   Douglas PS, Ginsburg GS. The evaluation of chest pain in women. N Engl J Med 1996;334:1311-1315
   Full Text | Web of Science | Medline

2. 2

   Patterson RE, Horowitz SF. Importance of epidemiology and biostatistics in deciding clinical strategies for using diagnostic tests: a simplified approach using examples from coronary artery disease. J Am Coll Cardiol 1989;13:1653-1665
   CrossRef | Web of Science | Medline

3. 3

   Goldman L. Cost-effective strategies in cardiology. In: Braunwald E, ed. Heart disease: a textbook of cardiovascular medicine. 4th ed. Vol. 2. Philadelphia: W.B. Saunders, 1992:1694-707.
   

4. 4

   Morise AP, Diamond GA, Detrano R, Bobbio M. Incremental value of exercise electrocardiography and thallium-201 testing in men and women for the presence and extent of coronary artery disease. Am Heart J 1995;130:267-276
   CrossRef | Web of Science | Medline

5. 5

   Shaw LJ, Miller DD, Romeis JC, Kargl D, Younis LT, Chaitman BR. Gender differences in the noninvasive evaluation and management of patients with suspected coronary artery disease. Ann Intern Med 1994;120:559-566
   Web of Science | Medline

Author/Editor Response

The authors reply:

To the Editor: We thank Auerbach et al. for their careful reading of our review. We agree with their statement that Bayes' theorem must be taken into account in the interpretation of any test result. Thus, as pointed out, a negative test result in a patient with a high pretest probability of disease results in an intermediate, rather than a low, post-test probability. Two issues remain. First, what exactly is that intermediate level of post-test probability? The article by Patterson and Horowitz1 cited by Auerbach et al. actually draws on data presented in an earlier study2 regarding pretest and post-test probabilities of coronary artery disease in women. Nomograms indicate that the post-test probability of coronary artery disease for a 55-year-old woman with typical chest pain after a negative exercise-tolerance test is 25 to 40 percent, rather than 47 percent. The pooled data from the literature cited by Goldman3 include mostly male subjects and cannot be extrapolated to apply to women. Finally, the data suggest that the pretest likelihood of coronary artery disease in a middle-aged woman with typical chest pain is actually lower than 80 percent: in the Coronary Artery Surgery Study, it was 62 percent,4 which would make the post-test probability even lower.

The second question is difficult: what should be done about an intermediate post-test probability? Although we recommended careful observation, other physicians may be more aggressive in referring patients for subsequent testing. We believe that this is part of the art of medicine rather than the science. That said, it is clear that myocardial perfusion scanning is of incremental value, but it also incurs additional costs and may yield a false positive result. Even Goldman suggests that patients with typical angina proceed directly to catheterization, since a negative thallium exercise test, while reducing post-test probability, still does not remove it from the intermediate range.3 The most cost-effective approach is still unknown. We believe that a conservative approach is justified, since women with negative exercise tests have an excellent prognosis whether or not they have coronary artery disease.5

Pamela S. Douglas, M.D.
Geoffrey S. Ginsburg, M.D., Ph.D.
Beth Israel Hospital, Boston, MA 02215

5 References

1. 1

   Patterson RE, Horowitz SF. Importance of epidemiology and biostatistics in deciding clinical strategies for using diagnostic tests: a simplified approach using examples from coronary artery disease. J Am Coll Cardiol 1989;13:1653-1665
   CrossRef | Web of Science | Medline

2. 2

   Patterson RE, Eng C, Horowitz SF. Practical diagnosis of coronary artery disease: a Bayes' theorem nomogram to correlate clinical data with noninvasive exercise tests. Am J Cardiol 1984;53:252-256
   CrossRef | Web of Science | Medline

3. 3

   Goldman L. Cost-effective strategies in cardiology. In: Braunwald E, ed. Heart disease: a textbook of cardiovascular medicine. 4th ed. Vol. 2. Philadelphia: W.B. Saunders, 1992:1698.
   

4. 4

   Weiner DA, Ryan TJ, McCabe CH, et al. Exercise stress testing: correlations among history of angina, ST-segment response and prevalence of coronary-artery disease in the Coronary Artery Surgery Study (CASS). N Engl J Med 1979;301:230-235
   Full Text | Web of Science | Medline

5. 5

   Weiner DA, Ryan TJ, Parsons L, et al. Long-term-prognostic value of exercise testing in men and women from the Coronary Artery Surgery Study (CASS) registry. Am J Cardiol 1995;75:865-870
   CrossRef | Web of Science | Medline