Letter Regarding Article by Pellikka et al, “Severe Asymptomatic Aortic Stenosis”
To the Editor:
We read with interest the article of Pellikka et al,1 a remarkable follow-up of 622 patients with hemodynamically significant aortic stenosis.
The authors conservatively conclude that “the majority of patients with asymptomatic, hemodynamically significant aortic stenosis will develop symptoms within 5 years,” with no further recommendation about surgery. We think the analysis of their data could suggest a more straightforward conclusion.
In Figure 2 of the article, they show that 72% of asymptomatic patients who underwent surgery survived, versus only 43% of those treated medically (a mortality of approximately 12% per year) (P<0.001).
Death was of cardiac causes in 9.8% of surgical patients versus 30.5% of medical patients (see Table 3).
They state in the Discussion section that “the protective effect of aortic valve surgery was highly significant in the multivariate analysis of predictors of cardiac death and all-cause mortality” (neither odds ratio nor confidence intervals are reported).
However, the most recent American Heart Association/American College of Cardiology guidelines on valvular disease management discourage aortic valve replacement in asymptomatic patients with severe aortic stenosis to prevent sudden death (class III). This is related to the combined risk of surgery and the late complications of a prosthesis (2% to 3% per year) and death directly related to the prosthesis (1% per year) reported in the literature,2–4 which is considered to exceed the possibility of preventing sudden death and prolonging survival in all asymptomatic patients.
Considering the very low mortality directly related to surgery in aortic valve replacement achieved in the majority of cardiothoracic centers nowadays (1.4% in this article1), we think that the new report by Pellikka et al should prompt a vigorous plea in favor of early surgery in asymptomatic patients with severe aortic stenosis, not simply a consideration about the probability that symptoms will sooner or later occur.
Pellikka PA, Sarano ME, Nishimura RA, Malouf JF, Bailey KR, Scott CG, Barnes ME, Tajik AJ. Outcome of 622 adults with asymptomatic, hemodynamically significant aortic stenosis during prolonged follow-up. Circulation. 2005; 111: 3290–3295.
Bonow RO, Carabello B, de Leon AC Jr, Edmunds LH Jr, Fedderly BJ, Freed MD, Gaasch WH, McKay CR, Nishimura RA, O’Gara PT, O’Rourke RA, Rahimtoola SH. ACC/AHA guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients With Valvular Heart Disease). J Am Coll Cardiol. 1998; 32: 1486–1588.
Hammermeister KE, Sethi GK, Henderson WG, Oprian C, Kim T, Rahimtoola S, for the Veterans Affairs Cooperative Study on Valvular Heart Disease. A comparison of outcomes in men 11 years after heart-valve replacement with a mechanical valve or bioprosthesis. N Engl J Med. 1993; 328: 1289–1296.
We appreciate your interest in our study, “Outcome of 622 Adults With Asymptomatic Hemodynamically Significant Aortic Stenosis During Prolonged Follow-Up.”1
We agree that indications for surgery for aortic stenosis should evolve with the knowledge of new data. Nonetheless, on the basis of our study, we may not be able to recommend operation in all patients with severe asymptomatic aortic stenosis, as you have suggested. As demonstrated in a multivariate analysis, aortic valve surgery was independently associated with improved survival (hazard ratio, 0.46; 95% CI, 0.34 to 0.63; P<0.0001). Furthermore, when we considered only the end point of cardiac death, aortic valve surgery was again independently predictive of reduced risk (hazard ratio, 0.41; 95% CI, 0.25 to 0.67; P=0.0003). However, our study was not a randomized trial, and it is possible that the selection of healthier patients for surgery by factors not captured in our database contributed to the apparent independent protective effect of surgery. There were 90 patients in our study who developed symptoms but who, because of age, comorbidities, patient preference, or failure to report these symptoms to the physician, did not undergo aortic valve surgery. The risk of sudden death in the asymptomatic patient in whom surgery was postponed was approximately 1% per year.
We are aware that there will be a new version of the American Heart Association/American College of Cardiology Guidelines for Valvular Heart Disease and that more recent data, including lower operative mortality for aortic valve replacement, better outcomes of valve prostheses, and the knowledge of the natural history of patients with severe aortic stenosis, have been taken into consideration. Nevertheless, without a randomized prospective study, there continues to be a need for clinical judgment in determining the best management for the asymptomatic patient with severe aortic stenosis. Patient age, comorbidities, and personal preference must be considered in making treatment decisions.