Significance of Controlling Hypertension in Patients with End-Stage Renal Disease

1. Significance of Controlling Hypertension in Patients with End-Stage Renal Disease Source: Horl WH. Hypertension in end-stage renal disease: Different measures and their prognostic significance. Nephrol Dial Transplant. 2010:1–6.

2. Blood pressure (BP) control might be an important target for the intervention to reduce cardiovascular mortality in the majority of hypertensive patients who start dialysis. • No consensus exists as to lower increased BP in hemodialysis (HD) patients or the level to which BP • should be targeted. • In addition, the accurate assessment of BP is difficult in this patient population. • National Kidney Foundation Disease Outcomes Quality Initiative (NKFKDOQI)- recommended peridialytic BP targets of <140/90 mmHg predialytic and <130/80 mmHg postdialytic results in an increased frequency of intradialytic hypotension. • Peridialytic BP measurements are used for the management of hypertension in the majority of HD patients. • Predialysis systolic BP between 140 and 160 mmHg and a predialysis diastolic BP between 70 and 90 mmHg is recommended in HD patients to reduce the risk of mortality.

3. A study found that a predialysis systolic BP <120 mmHg was associated with a higher risk of mortality compared with the reference group with a predialysis systolic BP between 140 and 159 mmHg. • The patterns of systolic BP, diastolic BP, mean arterial pressure (MAP) and pulse pressure (PP) in HD patients differs markedly with that of the general population. • An increase in systolic BP, diastolic BP, MAP and PP was observed among young HD patients reflecting an acceleration of cardiovascular diseases in these patients. • This suggests that in this subgroup of patients, BP-lowering therapy may be beneficial. • Dry-Weight Reduction in Hypertensive Hemodialysis (DRIP) trial supports the use of home BP measurement in HD patients. • After 18–30 h of completion of the dialysis treatment, home BP measurements are recommended. • In the absence of home BP monitoring among HD patients, intradialytic BP recordings may improve the diagnosis and management of hypertension.

4. Most patients undergoing HD require a number of antihypertensives in order to achieve the appropriate BP. • All classes of antihypertensives are used for controlling hypertension in HD patients; however, only a few HD patients may benefit from loop diuretics. • The metaanalysis by Agarwal and Sinha showed a cardiovascular benefit for hypertensive HD patients from BP lowering. • In a systemic review and meta-analyses of eight trials with data from 1,649 patients and 495 cardiovascular events performed to evaluate the effect of lowering the BP on cardiovascular events and mortality in patients on dialysis, it was found that reduction of BP was associated with lower risk of cardiovascular events, all cause mortality and cardiovascular mortality than control regimens. • This is shown in Table 1.

5. However, this result cannot be generalized for a large number of patients worldwide due to the clinical disparity in trials included for meta-analysis. • Use of angiotensin II receptor blockers (ARBs) reduces the number of deaths from congestive heart failure. • Amlodipine showed a significant reduction in the composite secondary endpoint of all-cause mortality or a cardiovascular event. Owing to hypotension, • hyperkalemia, and adverse metabolic effects with the use • of 􀁅-blockers, this class of drug is sparingly used in highrisk • patients. The treatment with angiotensin-converting • enzyme inhibition or ARB in HD patients shows reduced • left ventricular mass. For subjects without kidney disease • and with or without significant cardiovascular disease • burdens, any form of the BP-reducing therapy profoundly • reduced cardiovascular burdens.

6. A direct relationship between volume status and BP has been recognized in patients with end-stage renal disease (ESRD) treated with dialysis. • An increase in the predialytic systolic BP may reflect hypervolemia. Data from the CLIMB study, which was obtained from 442 subjects in 32,295 sessions and followed up for 6 months, confirmed that an increasing percentage of interdialytic weight gain (IDWG) is associated with a greater predialysis BP and a greater decrease in BP associated with HD. • A 15% or greater extracellular volume increase over the normal in HD patients increases the risk of mortality. • In the CLIMB study it was observed that peritoneal dialysis patients responded positively to a combined therapy of salt restriction (4 g/day, body weight) plus additional ultrafiltration by the addition of hypertonic dextrose solutions, which led to a significant decrease in the systolic and the diastolic BP. In dialysis patients, salt and water overload raises the BP.

7. Lifestyle modification is the key to restrict the dietary sodium intake. • The study have impressively demonstrated • that a dietary salt restriction for >36 months results in a decrease in the following parameters in maintenance HD patients (see Table 2).

8. A study assessed cardiac consequences of two different strategies for BP control in maintenance HD patients. • One group was put on salt a restriction (5 g/day) whereas the other group was given antihypertensive drugs. • Patients in the group who were put on salt restriction had significantly lower IDWG, lower left ventricular mass, lower frequency of left ventricular hypertrophy, better preserved systolic and diastolic functions and lower episodes of intradialytic hypotension in spite of similar systolic and diastolic BP values. • This may be possible as antihypertensive drugs may interfere with the compensatory vasoconstriction in BP maintenance in the face of rapid changes in intravascular volume during conventional HD.

9. Parallel reductions in awake and sleep BP without restoring a nocturnal dipping in HD patients is observed with augmented volume removal therapy. • Volume removal therapy reduces the systolic BP greater than the diastolic BP, which results in the reduction of PP, which has an impact on the survival of HD patients. • An increased death risk is associated with postdialysis PP >60 mmHg, but also for predialysis PP <55 mmHg. Lowering of the PP from before to after HD was associated with lower hospitalization and lower mortality outcomes.

10. Intradialytic hypertension may be a sign of volume excess. • Endothelin excess, sympathetic overactivity, activation of the renin–angiotensin–aldosterone system, or dialysisspecific factors, such as net sodium gain, high dialysate calcium, hypokalemia or removal of hypertensive medications can raise the intradialytic BP. • Though recommendations to treat intradialytic hypertension exist, these recommendations are not validated by studies.

11. In ESRD patients, long, slow, home HD or frequent, short HD sessions or nocturnal HD also result in the reduction of BP and left ventricular hypertrophy. • Thrice-weekly incenter nocturnal HD is an effective strategy to optimize BP, which is supported with a study. • The study found a decrease in the systolic and the diastolic BP in seven maintenance HD patients at 2 years after starting nocturnal HD. • The results are shown in Table 3.

12. Normalization of BP associated with a significant reduction in the use of per patient antihypertensive agents. • The IDWG is associated with cardiovascular mortality. • Thus, lowering dialysate sodium might prevent IDWG and possibly decrease mortality. • To conclude, hypertension should be treated effectively as it affects a vast majority of HD patients. • Normovolemia is the key therapeutic target for hypertension in HD patients that can be achieved by ultrafiltration and dietary salt restriction. • Antihypertensive drugs may reduce cardiovascular complications, but a generalization cannot be made for heterogeneous patients undergoing HD.

13. Comprehensive Basketin Anemia Management