Targeting the renin angiotensin system in dialysis patients

Patients on chronic dialysis therapy have a dramatic excess cardiovascular risk compared to any other population, including those with overt diabetic nephropathy. Despite this, patients on dialysis are almost invariably excluded from trials evaluating the cardioprotective effect of novel treatments. Consistent evidence is available that inhibitors of the renin-angiotensin system, such as angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs), are more cardioprotective than other antihypertensive agents in patients with chronic renal disease or diabetes (with or without renal involvement), but whether this applies also to patients on dialysis is unknown. However, clear evidence is available that ACE inhibitors and ARBs reduce morbidity and mortality in patients on dialysis with heart failure (HF) or atrial fibrillation (AF). Moreover, these drugs may preserve residual renal function in those with preterminal kidney failure as well as vascular access and peritoneal membrane function in those on extracorporeal or peritoneal dialysis, respectively. These drugs also show an excellent tolerability profile in this population. Thus, ACE inhibitors and ARBs are indicated in patients on dialysis with HF or AF. Available evidence suggests that they should be first-choice therapy in patients on dialysis with hypertension, though trials are still needed to formally demonstrate their superior cardioprotective effect over other antihypertensives in this population.