Background— We sought to assess the outcome of asymptomatic patients with very severe aortic stenosis. Methods and Results— We prospectively followed 116 consecutive asymptomatic patients (57 women; age, 67±16 years) with very severe isolated aortic stenosis defined by a peak aortic jet velocity (AV-Vel) ≥5.0 m/s (average AV-Vel, 5.37±0.35 m/s; valve area, 0.63±0.12 cm ² ). During a median follow-up of 41 months (interquartile range, 26 to 63 months), 96 events occurred (indication for aortic valve replacement, 90; cardiac deaths, 6). Event-free survival was 64%, 36%, 25%, 12%, and 3% at 1, 2, 3, 4, and 6 years, respectively. AV-Vel but not aortic valve area was shown to independently affect event-free survival. Patients with an AV-Vel ≥5.5 m/s had an event-free survival of 44%, 25%, 11%, and 4% at 1, 2, 3, and 4 years, respectively, compared with 76%, 43%, 33%, and 17% for patients with an AV-Vel between 5.0 and 5.5 m/s ( P II) than those with an AV-Vel between 5.0 and 5.5 m/s (27%; P =0.03). Conclusions— Despite being asymptomatic, patients with very severe aortic stenosis have a poor prognosis with a high event rate and a risk of rapid functional deterioration. Early elective valve replacement surgery should therefore be considered in these patients.

In the western world, calcific aortic stenosis (AS), the most common valvular heart disease, represents a major public health burden.¹ Currently, there is no pharmacological treatment that prevents or slows the progression of AS.² Surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) are the only therapies to significantly improve both survival and symptoms^3,4 and are recommended in symptomatic patients with severe AS.^5,6 Quiz Ref ID The management of patients with asymptomatic severe AS, particularly the choice between early intervention vs watchful waiting, continues to be a matter of debate.^7,8 Current guidelines advocate delaying AVR until symptoms or left ventricular (LV) systolic dysfunction develop.^5,6 However, observational studies in 2010⁹ and 2015¹⁰ have suggested that early elective AVR might improve outcomes in patients with severe asymptomatic AS. This approach has been reinforced by continued advances in surgical techniques and aortic valve prostheses, the advent of TAVR, and the low perioperative mortality and morbidity rates achieved in valve centers of reference.^11,12 However, preemptive surgery before onset of symptoms or LV systolic dysfunction is considered in only a selected group of patients after careful risk stratification. This is at least in part because the evidence for intervention in asymptomatic severe AS is derived from small, heterogeneous, retrospective, single-center studies, which have generally included the need for AVR (not always motivated by the development of symptoms or LV dysfunction) in the composite study end point.^13-20 Moreover, decision making for AVR remains particularly difficult in older patients in whom it is sometimes unclear if the benefits of intervention outweigh the risk.^5,6

We sought to assess the efficacy of a heart valve clinic (HVC) follow-up programme for patients with severe aortic stenosis (AS). Three hundred and eighty-eight consecutive patients with AS (age 71 ± 10 years; aortic-jet velocity 5.1 ± 0.6 m/s) and an indication for aortic valve replacement (AVR) were included. Of these, 290 patients presented with an indication for surgery at their first visit at the HVC and 98 asymptomatic patients who had been enrolled in an HVC monitoring programme developed indications for surgery during follow-up. Time to symptom detection was significantly longer in patients that presented with symptoms at baseline (352 ± 471 days) than in patients followed in the HVC (76 ± 75 days, P < 0.001). Despite being educated to recognize and promptly report new symptoms, 77 of the 98 patients in the HVC programme waited until the next scheduled consultation to report them. Severe symptom onset (NYHA or CCS Class ≥III) was present in 61% of patients being symptomatic at the initial visit and in 34% of patients in the HVC programme (P < 0.001). Delays in referral and symptom reporting as well as symptom denial are common in patients with AS. These findings support the concept of risk stratification to identify patients who may benefit from elective surgery. A structured HVC programme results in the detection of symptoms at an earlier and less severe stage and thus in an optimized timing of surgery.