A vigorous 61-year-old man presents for a preemployment physical examination.He has no symptoms of angina pectoris or congestive heart failure (CHF).
A vigorous 61-year-old man presents for a preemployment physical examination.He has no symptoms of angina pectoris or congestive heart failure (CHF).HISTORYThe patient has no history of diabetes, hypertension, or other significantillness. He maintains an active lifestyle that includes golf and tennis. Hetakes aspirin, 81 mg/d, which was prescribed for cardiovascular prophylaxis.His father had "some form of heart trouble" in his later years.PHYSICAL EXAMINATIONThe patient appears healthy. Respiration rate is 16 breaths per minute;heart rate, 72 beats per minute; and blood pressure, 105/70 mm Hg. Chest isclear. Heart beat is regular; however, a grade 2/3 rasping systolic ejectionmurmur is audible at the base with radiation to the neck. Carotid pulses aredampened and delayed. There is no edema, and results of the remainder ofthe examination are normal.LABORATORY AND IMAGING RESULTSResults of laboratory studies performed before the patient's visit wereunremarkable; however, an ECG showed voltage criteria for left ventricularhypertrophy. A cardiac ultrasound scan, prompted by the physical examinationresults, yields the following findings:
Which of the following is the most appropriate next step for this patient?
Refer him for cardiac catheterization and surgical evaluation for valvereplacement.
Refer him for exercise stress testing under monitored conditions.
Initiate medical therapy with simvastatin, atenolol, and digoxin andrepeat the ultrasound scan in 6 months.
Arrange for follow-up at 3- to 6-month intervals with echocardiography--as long as the aortic valve gradient remains below 65 mm Hg.
CORRECT ANSWER: B
This patient has
one of the most commonvalvular diseases. The narrow pulse pressure, the typicalcoarse systolic ejection-type murmur with radiation to theneck, and the delay and dampening of the carotid pulsesare all strong clinical clues to the diagnosis. Appropriately,these findings prompted an echocardiographic evaluationto assess disease severity; the study documented severalof the proven indicators of severe aortic stenosis. Theseinclude:
Thus, this patient manifests clear echocardiographicevidence of severe aortic stenosis even though he hasnone of thesymptoms traditionallyassociatedwith the condition--namely,angina, syncope,and CHF symptoms,which correlatewith mediansurvivals of 5years, 3 years,and 2 years, respectively.
Patientssuch asthis man are saidto have "asymptomaticbut severeaortic stenosis."A body of experience and literature supports a numberof management options for these patients.One strategy is to operate on all patients as soon asphysiologic criteria for severe aortic stenosis have beendocumented (choice A). This approach reduces mortalityin patients who have angina, syncope, or CHF symptoms.It has also been recommended for patients with asymptomaticbut hemodynamically severe aortic stenosis, becausesudden death occurs in 1% to 2% of such patients.
However, this aggressive approach poses the risk of a 1%surgical and perioperative mortality rate, along with a riskof prosthetic valve complications (valve dysfunction, endocarditis,and complications of anticoagulation), which occurat a rate of 1% per year and necessitate reoperation andvalve replacement.
Thus, most authorities do not recommendimmediate valve replacement for all patients withasymptomatic but severe disease.Medical therapy as an alternative to surgery (choiceC) can essentially be dismissed. There is
effective medicaltherapy for aortic stenosis, and the agents mentionedin choice C might even be counterproductive.Careful monitoring (choice D) is always a good ideain patients with aortic stenosis that is not yet known tobe hemodynamically severe. However, it is inadequate inthose with asymptomatic but severe aortic stenosis--again, because of the small but troubling percentage whoexperience rapid clinical deterioration or sudden death.Moreover, the 65 mm Hg gradient cutoff in choice D iswell past the point at which symptoms and deteriorationoccur in almost all patients.Evolving data suggest that exercise testing under theclose supervision of a physician is a safe and effective wayto identify patients who need surgery now rather thanlater.
However, this approach is suitable only for asymptomaticpatients; exercise testing is unwarranted and dangerousin patients with symptomatic aortic stenosis.
One study found that roughly one third of patientswith asymptomatic but severe aortic stenosis manifestedsymptoms for the first time at exercise testing; this placedthem in the symptomatic group, for whom surgical interventionis recommended. The remaining patients could besafely monitored at 6-month intervals with echocardiography(to detect worsening gradients or ejection fractions,and transaortic flow velocities of greater than 3 m/s) andexercise testing to detect symptoms that the patients hadnot mentioned--or had not experienced because of a lessactive lifestyle.
Thus, choice B is correct.
Outcome of this case.
The patient underwent exercisetesting. No unexpected low exercise tolerance, hemodynamicinstability, or latent symptoms were noted. Hewill be followed up with echocardiography and exercisetesting every 6 months, unless symptoms occur in theinterval.
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