In response to our Perspectives article (Vaishnava, P., Fuster, V., Goldman, M. & Bonow, R. O. Surgery for asymptomatic degenerative aortic and mitral valve disease. Nat. Rev. Cardiol. 8, 173–177 [2011])1 on asymptomatic valve disease, Gilmanov et al. (Gilmanov, D., Mazzone, A., Berti, S. & Glauber, M. Is comorbidity equivalent to symptoms in asymptomatic AS? Nat. Rev. Cardiol. doi:10.1038/nrcardio.2011.203-c1)2 correctly note the often insidious and not easily recognized onset of symptoms in aortic stenosis (AS). We agree that subtle and nonspecific symptoms might not be fully acknowledged by patients, or become falsely attributed to the effects of aging, deconditioning, or comorbidities. Gilmanov et al. also suggest that the “extent of comorbidity” could be considered a “symptom equivalent for prognostic stratification.” Although we agree that comorbidities are common in patients with severe AS, we would caution against this approach of ascribing symptom equivalency to a heterogeneous group of coexisting illnesses. Rather, we would advocate exercise testing with or without echocardiography to risk-stratify asymptomatic patients with AS, by unmasking symptoms and abnormal hemodynamic responses.3,4,5

The occurrence of exercise-limiting symptoms, such as breathlessness, fatigue at low workload, angina, dizziness, or syncope, predicts the development of symptoms, sudden cardiac death, and the need for aortic valve replacement (AVR) among asymptomatic patients with severe AS.6 Like Gilmanov and colleagues, we recognize the potential value of elevated levels of B-type natriuretic peptide in determining the optimum timing of AVR, but caution against firm recommendations for this approach at present.7

We agree that minimally invasive open-heart operative strategies might be an appropriate strategy in appropriately selected patients requiring surgical AVR. However, we feel strongly that transcatheter AVR is not yet ready for asymptomatic patients until more definitive data on feasibility, safety, and long-term efficacy are established.

Contributions

P. Vaishnava and R. O. Bonow wrote the article. All authors reviewed the article prior to submission.