Microalbuminuria breakthrough under chronic renin-angiotensin-aldosterone system suppression

Microalbuminuria has been shown to be a potent predictor for future development of cardiovascular and renal events that can be prevented by the use of angiotensin-converting enzyme inhibitors (ACEis) or angiotensin receptor blockers (ARBs). Both classes of drugs are now-a-days widely used in the treatment of arterial hypertension since the very early stages of the cardiorenal continuum when only cardiovascular risk factors are detected. We describe here the development of de-novo microalbuminuria in patients chronically treated with either an ACEi or an ARB at adequate doses.

We reviewed the evolution of 1433 patients (mean age 60.5 ± 12.4 years, 50.3% men, 6.6% having type 2 diabetes), arriving in our hospital-based Hypertension Unit previously treated for a least 2 years either with an ACEi or an ARB, at adequate doses, alone or in combination with other antihypertensive drugs.

A total of 184 (16.1%) patients developed new-onset microalbuminuria, whereas macroalbuminuria was detected in 11 (1.0%) patients at the end of follow-up. Albuminuria appeared at any level of blood pressure (BP) from below 130/80 mmHg, albeit the highest percentage was seen when SBP was above 160 mmHg. De-novo microalbuminuria was more frequent in those patients presenting with established cardiovascular disease and predicts the future development of cardiovascular events but was not accompanied by a significant worsening of renal function.

These data indicate that a reappraisal of renin-angiotensin-aldosterone system (RAAS) suppression is required when microalbuminuria appears in patients under chronic RAAS suppression.