By Amar Krishnaswamy and Murat Tuzcu
Without aortic valve replacement, patients with severe, symptomatic aortic stenosis experience a 50% mortality rate at 1–2 years. Recent advances in transcatheter aortic valve replacement have shown efficacy and safety in patients with high or prohibitive surgical risk, bringing a new treatment to patients who were not previously considered for surgical aortic valve replacement. In large part due to rising interest in the management of patients with aortic stenosis, and the anticipated diffusion of transcatheter aortic valve replacement, balloon aortic valvuloplasty has seen a resurgence in recent years.
There are a number of situations in which balloon aortic valvuloplasty may be considered. In patients with severe aortic stenosis who are haemodynamically unstable, and for whom urgent aortic valve replacement is not feasible, balloon aortic valvuloplasty may serve as a “bridge” to valve replacement. Similarly, we have also seen significant functional improvement in patients after balloon aortic valvuloplasty so that patients initially unable to undergo aortic valve replacement have improved to a point that transcatheter or surgical aortic valve replacement could be performed safely. In patients who require urgent non-cardiac surgery, balloon aortic valvuloplasty may be considered as a temporising measure in the hope of reducing the risks of perioperative haemodynamic changes associated with anesthesia.
A number of patients with severe aortic stenosis have other comorbidities, such as chronic obstructive pulmonary disease or liver or kidney disease, that make it difficult to discern the degree to which aortic stenosis contributes to their symptoms. In such cases, balloon aortic valvuloplasty may provide a therapeutic answer; improvement of symptoms points to aortic stenosis as the driver of symptoms and may push for a more definitive valve replacement option. Finally, in patients without any option for either transcatheter or surgical aortic valve, balloon aortic valvuloplasty may be considered as a palliative measure.
Procedural success with balloon aortic valvuloplasty is typically defined as a 50% reduction in mean aortic valve gradient and a 25% increase in aortic valve area; most patients usually experience almost 50% increase in aortic valve area. Unfortunately, as implied in the indications above, the durability of balloon aortic valvuloplasty is only temporary and restenosis generally occurs within a period of 6–12 months. Therefore, balloon aortic valvuloplasty as a stand-alone procedure is limited, and overall survival is significantly improved when valvuloplasty is used as a bridge to valve replacement.
It should be noted that balloon aortic valvuloplasty carries some risk. The 30-day mortality associated with the procedure may be up to 10%, usually due to either aortic regurgitation (as a complication of the balloon procedure) or persistent heart failure. Other complications include peripheral vascular complications (due to the size of the devices used and concomitant incidence of peripheral arterial disease), aortic dissection, stroke, need for permanent pacemaker implantation, and cardiac arrest. In patients who present a need for repeat balloon aortic valvuloplasty, the procedure can be performed with similar risks and outcome as the first procedure.
Overall, balloon aortic valvuloplasty holds an important place in the treatment of patients with severe aortic stenosis. In our experience, balloon aortic valvuloplasty is most often performed to bridge severely symptomatic patients to transcatheter or surgical aortic valve replacement, or to better understand the contribution of aortic stenosis to functional limitation in patients with multiple comorbidities. Balloon aortic valvuloplasty has tremendous potential to alleviate symptoms and provide an opportunity for functional improvement that allows definitive treatment with aortic valve replacement and improved quality and quantity of life in patients with severe aortic stenosis.
Amar Krishnaswamy and Murat Tuzcu, Cleveland Clinic, USA