Plasma renin and cardiovascular risk: what is the evidence for an association?

Renin is a key component of the renin-angiotensin system (RAS), which plays an important role in the maintenance of blood pressure and electrolyte-volume homeostasis. RAS also plays a role in cardiovascular (CV) disease as a result of effects on inflammation and oxidative stress. There is growing evidence that plasma renin activity may be a marker of CV risk in hypertensive patients. This increase in CV risk likely reflects activation of the RAS as a whole. Patients undergoing treatment for hypertension experience a reactive increase in renin, especially if treated with diuretics, vasodilators or agents that block the RAS. There is not sufficient evidence, however, that this reactive increase in renin is intrinsically harmful for hypertensive patients in whom adequate levels of RAS blockade have been achieved. Indeed, in such patients, additional RAS blockade may not be beneficial and may even increase the risk of adverse events. Plasma renin may be an important prognostic indicator in untreated patients, and one that can be used to help in the choice of antihypertensive treatment. Currently, however, the link between plasma renin and CV risk in treated patients is inconsistent between different populations and in various clinical conditions, calling for further investigation.