In teaching and practicing the art of physical diagnosis, by slappypappy112


									Examining Older People for Carotid Bruits
Listen to Your Patient, Not Her Neck

I   n teaching and practicing the art of physical diagnosis,
    we must continually ask: What parts of the physical
examination should we keep? And what parts should we
                                                                County, Georgia, found higher risks of stroke in asymp-
                                                                tomatic persons with carotid bruit,10,11 and the risk asso-
                                                                ciated with carotid bruit may decrease with age, especially
put on the shelf? Some time-honored elements of the pe-         in persons older than 70 years.12
riodic physical examination, such as auscultation of the             Nonetheless, Shorr et al. concluded that carotid bruit
lungs or measurement of temperature, are of little diag-        was not a useful indicator of increased stroke risk in their
nostic value when used for screening asymptomatic pa-           study population. Several arguments support this conclu-
tients.1,2 Other elements of the physical examination also      sion. First, many strokes in patients with a unilateral ca-
are of little value when we apply them imperfectly—for ex-      rotid bruit occurred on the contralateral side and thus
ample, when we do not identify a cardiac murmur accu-           were unlikely to be related directly to the lesion causing
rately or fail to detect an enlarged spleen.3,4 Time spent      the bruit. Previous epidemiologic studies have reported
teaching or using skills of little value is time we do not      similar findings.10,11 These findings are consistent with
spend teaching, improving, or practicing skills of greater      other findings that the presence of a bruit does not accu-
value. In this era of corporate medicine, shortened patient     rately reflect the presence of significant stenosis and that
visits, and competing demands, our time is precious.            the absence of a bruit does not rule out carotid disease.8
     Auscultation of the carotid arteries has convention-       Second, the association between carotid bruit and stroke
ally been part of the physical examination, especially for      is confounded by other factors. Figure 1 in the article by
older patients because of their increased risk for cere-        Shorr et al. provides a classic demonstration of
brovascular disease. Should we listen to their carotids         confounding13: the relative risk of stroke in patients with
routinely?                                                      carotid bruit fell when underlying risk of stroke was taken
     Routine auscultation of the carotids has a compelling      into account in a stratified analysis. Finally, the absolute
rationale. In the asymptomatic patient, a bruit may indi-       risk of stroke associated with carotid bruit was small in
cate occult carotid artery stenosis that can be repaired        their patients, and it was not statistically significant in
surgically before it causes stroke, thus preventing the un-     most analyses. Thus, only a slight benefit could be gained
suspecting patient from death or crippling stroke. This ra-     by repairing carotid stenoses that were found in asymp-
tionale is now supported by evidence from an excellent          tomatic patients because carotid bruits were detected.
clinical trial, the Asymptomatic Carotid Artherosclerosis            We agree with Shorr et al. Moreover, the conclusion
Study (ACAS), which found that endarterectomy reduced           that time should not be wasted listening for carotid bruits
the risk over 5 years for ipsilateral stroke, perioperative     most likely is generalizable to other asymptomatic patients
stroke, or death from 11.0% to 5.1%.5 Nonetheless, de-          in the broader population. A recent cost-effectiveness anal-
spite the allure of finding a carotid bruit, some authorities   ysis used the results of the ACAS, which provides the most
have weighed in against screening for carotid disease in        favorable information to date on the potential benefits of
asymptomatic patients.6–8                                       screening for asymptomatic carotid disease.7 This analysis
     In this issue of JGIM, Shorr et al. contribute to our      found that ultrasonographic screening of 65-year-old men
thinking about the value of searching for asymptomatic          would on average extend their quality-adjusted life span by
carotid bruits.9 They used data from the landmark Sys-          approximately 5 days. The costs associated with this strat-
tolic Hypertension in the Elderly Program to study 4,442        egy were so high that routine screening was estimated to
community-dwelling persons who were aged 60 years or            cost $120,000 per quality-adjusted life-year, which is sub-
older and had no history of stroke, transient ischemic at-      stantially more than is usually considered acceptable. This
tack, or myocardial infarction. The annual rates of stroke      conclusion would not be changed substantially by a less
were 1.86% in persons who had carotid bruits noted on           expensive screening method, such as auscultation, even if
enrollment and 1.21% in those without carotid bruits.           it were as accurate as ultrasonography.
Therefore, the absolute risk of stroke was 0.61% higher              In summary, given current data, the time limits of
per year in those with carotid bruits compared with those       clinical practice, and the greater importance of other risk
without carotid bruits, and the relative risk was 1.53          factors such as hypertension and smoking, we cannot
(95% confidence interval [CI] 0.98, 2.40). Also, two sub-       recommend routine carotid auscultation in asymptomatic
groups of patients, those with unilateral bruit and those       patients. Rather, we should concentrate our efforts on
aged 60 to 69 years, had even higher absolute risks (ap-        what we have learned about the efficacy and appropriate-
proximately 1% per year) and relative risks (approxi-           ness of other medical and surgical interventions to de-
mately 2). Although these results did not quite reach the       crease the risk of stroke.14 It is now well established that
conventional standards of statistical significance, they are    aspirin and other platelet inhibitors decrease stroke rates
consistent with earlier studies. Prospective, population-       modestly in high-risk patients, that warfarin prevents
based studies in Framingham, Massachusetts, and Evans           most strokes in persons over age 60 who have atrial fibril-
JGIM                                                      Volume 13, February 1998                                                          141

lation (and that warfarin is more effective than aspirin),                4. Grover SA, Barkun AN, Sackett DL. Does this patient have
that antihypertensive drugs lower stroke rates even in                       splenomegaly? JAMA. 1993;270:2218–21.
                                                                          5. Executive Committee for the Asymptomatic Carotid Atherosclero-
older adults with isolated systolic hypertension, that low-
                                                                             sis Study. Endarterectomy for asymptomatic carotid stenosis.
ering the cholesterol level with statins in patients with                    JAMA. 1995;273:1421–8.
coronary heart disease lowers stroke risk as well, and                    6. Barnett HJM, Meldrum HE, Eliasziw M. The dilemma of surgical
that carotid endarterectomy reduces stroke risk in symp-                     treatment for patients with asymptomatic carotid disease. Ann In-
tomatic persons with more than 70% stenosis. Until we                        tern Med. 1995;123:723–5.
                                                                          7. Lee TT, Solomon NA, Heidenreich PA, Oehlert J, Garber AM. Cost-
learn more, we should make greater use of these manage-
                                                                             effectiveness of screening for carotid stenosis in asymptomatic
ment strategies and not listen for carotid bruits in asymp-                  persons. Ann Intern Med. 1997;126:337–46.
tomatic patients.—LOUISE ARONSON, MD, and C. SETH                         8. Sauve JS, Laupacis A, Ostbye T, Feagan B, Sackett DL. Does this
LANDEFELD, MD, The Division of Geriatrics and the Center                     patient have a clinically important carotid bruit? JAMA. 1993;
on Aging, University of California San Francisco, and the                    270:2843–5.
                                                                          9. Shorr R, Johnson K, Wan J, et al. The prognostic significance of
San Francisco Veterans Affairs Medical Center.
                                                                             asymptomatic carotid bruits in the elderly. J Gen Intern Med. 1998;
                                                                         10. Wolf P, Kannel W. Sorlie P, McNamara P. Asymptomatic carotid bruit
                          REFERENCES                                         and risk of stroke. The Framingham study. JAMA. 1981; 245:1442–5.
                                                                         11. Heyman A, Wilkinson W, Heyden S, et al. Risk of stroke in asymp-
 1. DiGuiseppi C, Atkins D, Woolf S, eds. U.S. Preventive Services           tomatic persons with cervical arterial bruits: a population study in
    Task Force. Guide to Clinical Preventive Services. 2nd ed. Alexan-       Evans County, Georgia. N Engl J Med. 1980;302:838–41.
    dria, Va: International Medical Publishing; 1996.                    12. Van Ruiswyk J, Noble H, Sigmann P. The natural history of ca-
 2. Oboler SK, LaForce FM. The periodic physical examination in              rotid bruits in elderly persons. Ann Intern Med. 1990;112:340–3.
    asymptomatic adults. Ann Intern Med. 1989;110:214–26.                13. Miettinen OS, Cook EF. Confounding: essence and detection. Am
 3. Mangione S, Nieman L. Cardiac auscultatory skills of internal            J Epidemiol. 1981;114:593–603.
    medicine and family practice trainees: a comparison of diagnostic    14. Barnett H, Eliasziw M, Meldrum H. Drugs and surgery in the pre-
    proficiency. JAMA. 1997;278:717–22.                                      vention of ischemic stroke. N Engl J Med. 1995;332:238–48.

To top