Renin-angiotensin system blockade in aortic stenosis?

Renin-angiotensin system blockade in aortic stenosis?

Renin-angiotensin system blockade in aortic stenosis? Conventionally afterload reducing agents like angiotensin converting enzyme inhibitors and angiotensin receptor blockers are not favoured in severe aortic stenosis because a fall in systemic vascular resistance may even lead to syncope in these individuals with a relatively fixed cardiac output. Now Nadir AM and associates [Nadir AM et al. Impact of Renin-Angiotensin System Blockade Therapy on Outcome in Aortic Stenosis. J Am Coll Cardiol 2011 58: 570-576] have come out with an interesting observation from a retrospective analysis that renin-angiotensin blockade may in fact be useful in aortic stenosis. They could identify over two thousand one hundred patients with aortic stenosis from a database which was linked to health informatics database with information on dispensed prescribing, morbidity and mortality. About one third of these patients were on angiotensin receptor blockers or angiotensin receptor blockers. The investigators found that over a mean follow up of over four years, there was a significantly lower all cause mortality and few cardiovascular events in those on angiotensin converting enzyme inhibitors or angiotensin receptor blockers. It is possible that patients with co-existing coronary artery disease and myocardial ischemia could have had a cardioprotective effect from the angiotensin converting enzyme (ACE) inhibitor therapy. Atherosclerotic plaque stabilization and consequent reduction in cardiovascular events could be a contributory factor. Antiarrhythmic effect of higher potassium levels during this therapy is also plausible as aortic stenosis patients can have arrhythmic substrates.

It has been noted earlier that ACE inhibitors can reduce aortic valve calcification [O’Brien KD et al. Angiotensin-converting enzyme inhibitors and change in aortic valve calcium. Arch Intern Med 2005;165:858-862].