Hypertension in Patients Receiving Dialysis: A Review of the Current Clinical Approach

Abstract

Cardiovascular disease is a leading cause of morbidity and mortality in end-stage renal disease (ESRD). Hypertension plays a major contributory role, resulting in progressive left ventricular hypertrophy, and increasing the risk of sudden cardiac death. The prevalence and pathophysiological mechanisms differ fundamentally from the non-dialysis-dependent population. Sodium restriction can be as effective as antihypertensive medication in mitigating the haemodynamic effects resulting from impaired sodium handling. Tailoring dialysate sodium may enhance diffusion and facilitate greater sodium elimination where dietary measures alone prove ineffective. Unlike hypertension in the wider population, volume overload plays a major pathophysiological role in ESRD. Probing dry weight in patients on dialysis who are seemingly euvolaemic enables clinically significant blood pressure (BP) reduction, and translates to improvements in markers of future cardiovascular morbidity and mortality. Pharmacotherapy remains an important aspect in controlling hypertension in dialysis. Although no large-scale studies have identified the optimal medical therapy, numerous meta-analyses and randomised control trials (RCT) have demonstrated the efficacy of angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARB), calcium channel blockers, β-blockers, and hydralazine/isosorbide dinitrate in the treatment of hypertension in ESRD. Whether the beneficial haemodynamic properties of mineralocorticoid receptor antagonists outweigh the risk of hyperkalaemia is the subject of ongoing RCTs. Numerous meta-analyses have demonstrated that adequate pharmacological control of BP translates to improved cardiovascular morbidity and mortality. The fluctuation of volume status in the inter/intra-dialytic period complicates the diagnosis of hypertension in ESRD. As with patients not receiving dialysis, 24-hour blood pressure monitoring appears to have the greatest sensitivity in diagnosing hypertension and predicting outcomes from hypertension. Where resources are limited, home BP monitoring appears to have the greatest value.