Aortic Stenosis - Treatment
The only effective treatment for aortic stenosis is removal of the mechanical obstruction. To this end, only aortic valve replacement (AVR) has been shown to achieve this while reducing mortality.
Transcatheter aortic valve replacement is now FDA approved for those patients who are not surgical candidates due to age and comorbid medical conditions and is being performed successfully in many major medical centers. Aortic valve debridement via surgery or ultrasound debridement is a poor alternative to AVR. High rates or aortic regurgitation occur with these procedures and the aortic stenosis may recur in a large percentage of patients. Pharmacological therapy is in general not effective in aortic stenosis. In fact, in severe aortic stenosis, many of the standard cardiovascular medications such as ACE inhibitors and B-blockers are considered to be relatively contraindicated when hypotension is present from low cardiac output.
Aortic balloon valvuloplasty is very beneficial in congenital aortic stenosis where no calcification of the aortic valve has occurred, however, every other type of aortic stenosis is accompanied by significant calcification and this modality is generally not effective. In adults with aortic stenosis, valvuloplasty does not result in regression of left ventricular hypertrophy. In fact, at 6 months after valvuloplasty about 50% of patients have completely restenosed their aortic valve to the same extent as before the procedure. The procedural mortality rate is 2-5%, similar to that of AVR. In addition, long term studies have shown that the overall mortality of patients undergoing valvuloplasty for aortic stenosis is the same as if they did not have the procedure at all. Therefore, the role of valvuloplasty is limited to palliative treatment of severe aortic stenosis or as a bridge to AVR in patients who are unable to immediately undergo a major surgery.
Surgical AVR is the definitive treatment for all types of aortic stenosis excluding congenital aortic stenosis. Any patient who is symptomatic from aortic stenosis should undergo AVR as soon as possible. AVR is generally not indicated if asymptomatic unless echocardiographic surveillance reveals rapidly progressing aortic stenosis with LV dysfunction or severe calcification of the aortic valve. Even in patients with critical aortic stenosis, AVR is still beneficial and age is never considered a contraindication to surgery. The ejection fraction may double or even return to normal and the LVH frequently regresses. It is rarely ever considered too late to replace the aortic valve in patients with critical aortic stenosis unless coexisting conditions increase the risk of surgery.
A good approach to aortic stenosis is to follow regular echocardiograms and if the mean pressure gradient is > 25 mmHg, repeat the history and physical every 6 months and instruct the patient to notify their physician if any signs or symptoms of aortic stenosis develop.
In general, patients with a low transaortic valve gradient of less than 25 mmHg and advanced heart failure do not improve after AVR. It is thought that in this subgroup irreversible myocardial remodeling has already occurred. However, a minority of these patients do improve significantly after AVR, so the risks of no improvement must be discussed with these patients before AVR is undertaken.