A 79-Year-Old Woman With a Known Heart Murmur and New Cardiac Symptoms
A 79-year-old woman returned to the office to report a change in her symptoms. She had come to the practice approximately 2 years previously, at which time a heart murmur had been detected.
Investigation at the time revealed stage C1 aortic stenosis (AS), which is defined as a patient who is entirely asymptomatic but in whom echocardiography manifests the hemodynamic parameters of severe AS—that is, significant calcification of the valve indicated by an aortic valve maximum velocity (Vmax) of 4 m/s or greater and a transvalvular gradient of 40 mm Hg or greater, but a normal ejection fraction (EF) of more than 50%.
History and Physical Examination
Echocardiography findings at that time were as follows: Vmax, 4.2 m/s; transvalvular gradient, 52 mm Hg; and EF, 55%. She had been cautioned to report any symptom change.
She now reported that during a brisk walk or when going up a flight of stairs, she experiences a profound feeling of fatigue as well as moderate shortness of breath that requires her to stop for several minutes and then slowly continue.
Physical examination revealed a healthy-appearing woman with a pulse of 84 beats/min and a blood pressure of 114/75 mm Hg. Findings of the head, eyes, ears, nose, and throat examination were unremarkable. Her chest was clear to percussion and auscultation.
A coarse, holosystolic, rasping murmur was loudest at the cardiac base and radiated into the neck. There was delay and blunting of the carotid pulsations. There was no gallop rhythm. Her joints were normal, and she had no pedal edema.
Echocardiography was performed and revealed severe calcifications, a Vmax of 4.4 m/s, a transvalvular gradient of 57 mm Hg, and an EF of 50%. Laboratory evaluation revealed normal complete blood count and comprehensive metabolic panel findings.
Based on these findings, what is the optimal therapy for this patient?
A. Proceed to immediate transcatheter aortic valve replacement (AVR).
B. Initiate an aggressive medical regimen for congestive heart failure, and reevaluate in 3 to 6 months.
C. Proceed to immediate surgical AVR using a bioprosthetic valve.
D. Proceed to immediate surgical AVR using a mechanical valve.
See answer on next page.
Answer: C. Proceed to immediate surgical AVR using a bioprosthetic valve.
The patient now manifests symptomatic AS such that, regardless of hemodynamic data, the only effective therapy capable of preventing the significant associated 1- and 2-year mortality is replacing her aortic valve. Her AS now is classified as stage D1 (symptomatic; severe hemodynamic parameters with an EF of 50% or above), and she now is a candidate for AVR.1,2
The question is which method of AVR is appropriate and optimal for this patient. Because no medical therapy for symptomatic AS is capable of addressing either the symptoms or the mortality risk, Answer B simply is not correct.
A variety of risk factors need be evaluated to determine the nature of procedure (surgical or transcatheter) and the nature of valve replacement (mechanical or bioprosthetic). Surgical AVR remains the standard unless inoperable comorbidities are present.1-3 Even in today’s older patients, the overall mortality for surgical AVR is less than 3%, and the overall mortality after surgery is similar to an age-matched population without AS.1 The newer approach of transcatheter AVR still should be reserved for patients with a higher surgical risk for the open procedure. The 1- and 3-year survival rates of transcatheter AVR are similar to those of standard surgery, but the risks of perioperative stroke, major vascular complications, and aortic regurgitation with paravalvular leak are much higher with the transvalvular approach.4-6
Our patient had no significant comorbidities and seemed to be a very low-risk candidate such that a transcatheter procedure is not required, so Answer A is incorrect.
Finally, a decision about valve choice needs consideration. Bioprosthetic valves do not require anticoagulation but carry a reoperation risk, whereas mechanical valves last longer but require indefinite anticoagulation. Therefore, the patient’s age at surgery (ie, how long the valve needs to last) and the patient’s anticoagulation risk determine valve choice.1,7 Given that our patient is older than 70 (which is the general age at which bioprostheses are preferred, since eventual reoperation is less likely and indefinite anticoagulation in a geriatric patient is avoided), the use of a bioprosthetic valve and a standard surgical approach—Answer C—is the optimal choice here.
Outcome of the Case
The results of the new echocardiogram had not changed significantly from those of the test performed 2 years prior, with severe calcification and reduced leaflet motion of the aortic valve, a Vmax of 4.4 m/s, a valvular gradient of 57 mm/Hg, and an EF of 50%. However, the appearance of symptoms now has changed her AS stage to D1, which carries a 50% 1-year mortality rate and a greater than 70% 2-year mortality rate. AVR is required.
Cardiac catheterization revealed normal coronary arteries and no unusual anatomy. The patient’s performance status was good, and she underwent successful and uneventful surgical AVR with a bioprosthetic valve. She was well and symptom-free 6 months after surgery.
Take Home Message
Cases of aortic valvular stenosis can be followed with careful monitoring without an extensive mortality risk, so long as the patient is asymptomatic. However, once any of the classical symptoms (angina, syncope, congestive heart failure) ensue, the prognosis quickly worsens, with 2-year mortality exceeding 70%, and sudden death incidence exceeding the surgical mortality risk of 3%. Therefore, AVR is indicated in most cases (with exclusions for patients with profound coexisting morbidity and surgical risk). When surgical risk is deemed low or moderate, surgical AVR likely is still the optimal choice, although transvalvular replacement techniques are available depending on the patient’s specifics.8
Ronald Rubin, MD, is a professor of medicine at the Temple University School of Medicine and is chief of clinical hematology in the Department of Medicine at Temple University Hospital, both in Philadelphia, Pennsylvania.
References:
- Otto CM, Prendergast B. Aortic-valve stenosis—from patients at risk to severe valve obstruction. N Engl J Med. 2014;371(8):744-756.
- Nishimura RA, Otto CM, Bonow RO, et al. 2014 AHA/ACC guideline for the management of patients with valvular heart disease: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014;63(22):2438-2488.
- Walther T, Blumenstein J, van Linden A, Kempfert J. Contemporary management of aortic stenosis: surgical aortic valve replacement remains the gold standard. Heart. 2012;98(suppl 4):iv23-iv29.
- Smith CR, Leon MB, Mack MJ, et al; PARTNER Trial Investigators. Transcatheter versus surgical aortic-valve replacement in high-risk patients. N Engl J Med. 2011;364(23):2187-2198.
- Adams DH, Popma JJ, Reardon MJ, et al; U.S. CoreValve Clinical Investigators. Transcatheter aortic-valve replacement with a self-expanding prosthesis. N Engl J Med. 2014;370(19):1790-1798.
- Kodali SK, Williams MR, Smith CR, et al; PARTNER Trial Investigators. Two-year outcomes after transcatheter or surgical aortic-valve replacement. N Engl J Med. 2012;366(18):1686-1695.
- Eikelboom JW, Connelly SJ, Brueckmann M, et al; RE-ALIGN Investigators. Dabigatran versus warfarin in patients with mechanical heart valves. N Engl J Med. 2013;369(13):1206-1214.
- Reinöhl J, Kaier K, Reinecke H, et al. Effect of availability of transcatheter aortic-valve replacement on clinical practice. N Engl J Med. 2015;373(25):2438-2447.