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Blood Pressure Control in CKD Patients: Why Do We Fail to Implement the Guidelines?

2010; Elsevier BV; Volume: 55; Issue: 3 Linguagem: Inglês

10.1053/j.ajkd.2009.12.013

1523-6838

Gavin J. Becker, David C. Wheeler,

Dialysis and Renal Disease Management

Related Article, p. 441 Related Article, p. 441 We are continually reminded that in many patients with chronic kidney disease (CKD), blood pressure (BP) is not controlled to the target of < 130/80 mm Hg as recommended in most clinical practice guidelines (Table 1). The challenge is to establish how implementation of clinical practice guidelines can be improved. A high level of patient and physician awareness of the presence of hypertension, as in the Chronic Renal Insufficiency Cohort (CRIC) Study described by Muntner et al5Muntner P. Anderson A. Charleston J. et al.Hypertension awareness, treatment, and control in adults with CKD: results from the Chronic Renal Insufficiency Cohort (CRIC) Study.Am J Kidney Dis. 2010; 55: 441-451Abstract Full Text Full Text PDF PubMed Scopus (246) Google Scholar in this issue of the American Journal of Kidney Diseases, may lead to better control. The CRIC Study recruited 3,612 patients with an estimated glomerular filtration rate of 20-70 mL/min/1.73 m2 (0.33-1.17 mL/min/1.73 m2) not on dialysis therapy. At the time of enrollment, the relevant BP target was achieved in 46% of patients. This compares with 27% of individuals with an increased serum creatinine level in the Third National Health and Nutrition Examination Survey (NHANES III)1Peralta C.A. Hicks L.S. Chertow G.M. et al.Control of hypertension in adults with chronic kidney disease in the United States.Hypertension. 2005; 45: 1119-1124Crossref PubMed Scopus (138) Google Scholar and only 20.3% of patients with stage 3 CKD in the Kidney Early Evaluation Program (KEEP).3Sarafidis P.A. Li S. Chen S.C. et al.Hypertension awareness, treatment, and control in chronic kidney disease.Am J Med. 2008; 121: 332-340Abstract Full Text Full Text PDF PubMed Scopus (222) Google Scholar It seems unlikely that clinician ignorance of relevant BP guidelines has a major role in patients not achieving BP targets because such clinical practice guidelines have been widely available and well publicized since 2003.6Chobanian A.V. Bakris G.L. Black H.R. et al.Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure.Hypertension. 2003; 42: 1206-1252Crossref PubMed Scopus (10343) Google Scholar, 7National Kidney FoundationK/DOQI Clinical Practice Guidelines on Hypertension and Antihypertensive Agents in Chronic Kidney Disease.Am J Kidney Dis. 2004; 43: S1-S290PubMed Google Scholar Furthermore, in the analysis by Muntner et al5Muntner P. Anderson A. Charleston J. et al.Hypertension awareness, treatment, and control in adults with CKD: results from the Chronic Renal Insufficiency Cohort (CRIC) Study.Am J Kidney Dis. 2010; 55: 441-451Abstract Full Text Full Text PDF PubMed Scopus (246) Google Scholar of CRIC participants and a recent report from the Avantage de la Nephroprotection dans l'Insuffisance Renale (AVENIR) cohort study,4Thilly N. Boini S. Kessler M. Briancon S. Frimat L. Management and control of hypertension and proteinuria in patients with advanced chronic kidney disease under nephrologist care or not: data from the AVENIR Study (AVantagE de la Nephroprotection dans l'Insuffisance Renale).Nephrol Dial Transplant. 2009; 24: 934-939Crossref PubMed Scopus (14) Google Scholar although more than half the recruited patients had been seen by a nephrologist, these individuals did not have better BP control than those who had not. It could be argued that nephrologists had been referred patients with BP that was more difficult to control.Table 1Studies of BP Control and Percentage of Participants Achieving BP < 130/80 mm Hg in CKDReference/YearStudyLocationNo. of ParticipantsBP < 130/80 mm Hg (%)Peralta et al1Peralta C.A. Hicks L.S. Chertow G.M. et al.Control of hypertension in adults with chronic kidney disease in the United States.Hypertension. 2005; 45: 1119-1124Crossref PubMed Scopus (138) Google Scholar/2005NHANESUnited States3,21337De Nicola et al2De Nicola L. Minutolo R. Chiodini P. et al.Global approach to cardiovascular risk in chronic kidney disease: reality and opportunities for intervention.Kidney Int. 2006; 69: 538-545Crossref PubMed Scopus (121) Google Scholar/2006TABLE in CKDItaly1,05812Sarafidis et al3Sarafidis P.A. Li S. Chen S.C. et al.Hypertension awareness, treatment, and control in chronic kidney disease.Am J Med. 2008; 121: 332-340Abstract Full Text Full Text PDF PubMed Scopus (222) Google Scholar/2008KEEPUnited States10,81313Thilly et al4Thilly N. Boini S. Kessler M. Briancon S. Frimat L. Management and control of hypertension and proteinuria in patients with advanced chronic kidney disease under nephrologist care or not: data from the AVENIR Study (AVantagE de la Nephroprotection dans l'Insuffisance Renale).Nephrol Dial Transplant. 2009; 24: 934-939Crossref PubMed Scopus (14) Google Scholar/2009AVENIRFrance56625Muntner et al5Muntner P. Anderson A. Charleston J. et al.Hypertension awareness, treatment, and control in adults with CKD: results from the Chronic Renal Insufficiency Cohort (CRIC) Study.Am J Kidney Dis. 2010; 55: 441-451Abstract Full Text Full Text PDF PubMed Scopus (246) Google Scholar/2009CRICUnited States3,61246Note: Studies vary in many factors, including awareness of CKD in patients and clinicians, method of BP measurement, and severity of renal impairment.Abbreviations: AVENIR, Avantage de la Nephroprotection dans l'Insuffisance Renale; BP, blood pressure; CRIC, Chronic Renal Insufficiency Cohort; CKD, chronic kidney disease; KEEP, Kidney Early Evaluation Program; NHANES III, Third National Health and Nutrition Examination Survey; TABLE, TArget Blood Pressure LEvels in Chronic Kidney Disease. Open table in a new tab Note: Studies vary in many factors, including awareness of CKD in patients and clinicians, method of BP measurement, and severity of renal impairment. Abbreviations: AVENIR, Avantage de la Nephroprotection dans l'Insuffisance Renale; BP, blood pressure; CRIC, Chronic Renal Insufficiency Cohort; CKD, chronic kidney disease; KEEP, Kidney Early Evaluation Program; NHANES III, Third National Health and Nutrition Examination Survey; TABLE, TArget Blood Pressure LEvels in Chronic Kidney Disease. Almost certainly in clinical practice, a decision is made to accept a higher BP in some patients after consideration of other factors. Recommendations in clinical practice guidelines are not meant to be followed blindly; they are generally based on broad evidence and should be implemented in the context of the individual patient. For example, many clinicians are less aggressive in their approach to decreasing BP in certain circumstances, such as in the elderly and patients with diabetes. In such individuals, postural hypotension, decreasing glomerular filtration rate, or increasing plasma potassium level can be problematic,8Pickering T.G. Hall J.E. Appel L.J. et al.Recommendations for blood pressure measurement in humans and experimental animals—part 1: blood pressure measurement in humans—a statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research.Circulation. 2005; 111: 697-716Crossref PubMed Scopus (1669) Google Scholar such that the trade-off between the risks and long-term benefits of lower BP may be different than in younger individuals or those without diabetes. The CRIC investigators identified certain risk factors that associate with poor BP control and by doing so help clinicians by indicating which patients should be the focus of attention. However, their analysis cannot discern whether these risk factors predict higher BP because the hypertension was intrinsically more difficult to control or because treatment was less aggressive in their presence. After multivariate adjustment, the elderly, blacks, and patients with higher urinary albumin excretion rates were less likely to achieve target BPs. These observations are largely consistent with the NHANES, in which there was less patient or clinician awareness of hypertension or CKD.1Peralta C.A. Hicks L.S. Chertow G.M. et al.Control of hypertension in adults with chronic kidney disease in the United States.Hypertension. 2005; 45: 1119-1124Crossref PubMed Scopus (138) Google Scholar In clinical practice, other factors present at the time of diagnosis of CKD that influence BP may not be modifiable, such as the age of the patient, presence or absence of diabetes, and severity of kidney damage. This provides a good argument for the earlier diagnosis of CKD, hypertension, and diabetes in an effort to improve achievement of BP targets. From a clinician's viewpoint, what more can we do? Disappointingly, as mentioned, the benefit of review by a nephrologist has not been proved. Most nephrologists will probably see their major role as providing advice about the proper use of antihypertensive medications. Most patients will require several agents; in the CRIC Study, > 3 agents were prescribed in 58% of patients, whereas the mean number of agents in the AVENIR Study was 2.7.4Thilly N. Boini S. Kessler M. Briancon S. Frimat L. Management and control of hypertension and proteinuria in patients with advanced chronic kidney disease under nephrologist care or not: data from the AVENIR Study (AVantagE de la Nephroprotection dans l'Insuffisance Renale).Nephrol Dial Transplant. 2009; 24: 934-939Crossref PubMed Scopus (14) Google Scholar Interestingly, the CRIC investigators found that the higher the BP, the more agents were prescribed, suggesting that clinicians were attempting to gain control, but that their efforts were not universally successful. Types of agents prescribed were analyzed in CRIC, and better control was seen in the 53% of patients administered angiotensin-converting enzyme inhibitors and the 74% on any form of therapy that blocked the renin-angiotensin system, including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker combinations. Given the extensive literature encouraging renin-angiotensin system blockade, one might expect more than three-quarters of patients with CKD to be using these potent antihypertensive agents, and reasons that 26% were not receiving them warrants further study. Patient-related factors were also considered in the CRIC analysis. Ninety-eight percent of CRIC patients reported that they were following some type of lifestyle modification (weight loss, salt intake reduction, alcohol reduction, and exercise, in decreasing proportions). Overall or taken individually, this did not seem to associate with better BP control. Clearly, this issue requires further study; however, patient adherence may be a major issue. Patients with higher income and a higher level of formal education were more likely to achieve better BP control, at least in univariate analysis, in which confounders such as age and race are not considered. Patient adherence to antihypertensive advice and therapy could be affected by both income and education. It has been proposed that patients with chronic physical illnesses make a choice about whether to adhere to a particular element of therapeutic advice depending on their understanding of the cost, risks, and effort of doing so (their concerns) balanced against their perception of the advantageous outcomes hoped for (the necessity).9Horne R. Weinman J. Patients' beliefs about prescribed medicines and their role in adherence to treatment in chronic physical illness.J Psychosom Res. 1999; 47: 555-567Abstract Full Text Full Text PDF PubMed Scopus (1553) Google Scholar Accordingly, the cost and effort of using antihypertensive medications may be (and almost certainly are) barriers to their use in poorer patients, and the need may not be obvious to those with limited formal education. Clinicians need to take these issues into account and should consider limiting the costs of prescribed medications when this is likely to improve compliance. Patient understanding of why compliance with antihypertensive medications is important could be improved by a more concentrated effort to enhance understanding of the consequences of poor BP control. In essential hypertension, a randomized controlled trial has shown that better BP control was achieved when an effort was made to increase patient education.10Roumie C.L. Elasy T.A. Greevy R. et al.Improving blood pressure control through provider education, provider alerts, and patient education—a cluster randomized trial.Ann Intern Med. 2006; 145: 165-175Crossref PubMed Scopus (188) Google Scholar Another study based in Indo-Asia indicated that a combined strategy of home health education with annual training of general practitioners was more effective than either intervention alone or no intervention.11Jafar T.H. Hatcher J. Poulter N. et al.Community-based interventions to promote blood pressure control in a developing country: a cluster randomized trial.Ann Intern Med. 2009; 151: 593-601Crossref PubMed Google Scholar These concepts could be extended further to CKD and might be amply justified by the associated decrease in the cost, in terms of both patient outcomes and health care delivery, because better BP control may improve cardiovascular and renal outcomes. The management of type 1 diabetes may be an appropriate model. Individuals with type 1 diabetes are made aware of the risks related to poor blood glucose control, monitor their own performance, and adjust their own lifestyle and medications accordingly. They are given access to health care advice when necessary, as well as routine formal review, including evidence-based surveillance for adequacy of control (glycated hemoglobin) and complications. In the management of BP in patients with CKD, how often are our patients really aware of the reasons for BP control, the goals of treatment, and their achievement of these? How often do clinicians encourage them to monitor their own BP and even modify their therapy accordingly? Although we lack a circulating marker of recent BP control analogous to glycated hemoglobin (and perhaps we should seek one that reflects recent endothelial or smooth muscle stress), our strategies to involve patients in the control of their own BP are far short of those used for patients with type 1 diabetes. Muntner et al5Muntner P. Anderson A. Charleston J. et al.Hypertension awareness, treatment, and control in adults with CKD: results from the Chronic Renal Insufficiency Cohort (CRIC) Study.Am J Kidney Dis. 2010; 55: 441-451Abstract Full Text Full Text PDF PubMed Scopus (246) Google Scholar also raise the issue of the reliability of isolated clinic visit BP measurement to assess BP control. This applies not only to cross-sectional studies, but also to the care of individual patients. Comparisons, although admittedly few in patients with CKD, have suggested that clinic BP does not correlate well with mean awake ambulatory BP or BP recorded at home by the patient using automated BP monitors,12Andersen M.J. Khawandi W. Agarwal R. Pathogenesis and treatment of kidney disease and hypertension—home blood pressure monitoring in CKD.Am J Kidney Dis. 2005; 45: 994-1001Abstract Full Text Full Text PDF PubMed Scopus (102) Google Scholar, 13Wühl E. Hadtstein C. Mehls O. Schaefer F. et al.Home, clinic, and ambulatory blood pressure monitoring in children with chronic renal failure.Pediatr Res. 2004; 55: 492-497Crossref PubMed Scopus (112) Google Scholar as has been widely accepted in patients with essential hypertension.8Pickering T.G. Hall J.E. Appel L.J. et al.Recommendations for blood pressure measurement in humans and experimental animals—part 1: blood pressure measurement in humans—a statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research.Circulation. 2005; 111: 697-716Crossref PubMed Scopus (1669) Google Scholar In 1 study, ∼30% of patients with CKD with clinic BP ≥ 130/80 mm Hg had a lower mean awake ambulatory BP and 28% with clinic BP < 130/80 mm Hg had a higher mean awake ambulatory BP.12Andersen M.J. Khawandi W. Agarwal R. Pathogenesis and treatment of kidney disease and hypertension—home blood pressure monitoring in CKD.Am J Kidney Dis. 2005; 45: 994-1001Abstract Full Text Full Text PDF PubMed Scopus (102) Google Scholar Ambulatory and home BP assessment may better indicate prognosis than clinic BP in patients with CKD.14Agarwal R. Andersen M.J. Prognostic importance of clinic and home blood pressure recordings in patients with chronic kidney disease.Kidney Int. 2006; 69: 406-411Crossref PubMed Scopus (143) Google Scholar In patients with essential hypertension, it has recently been suggested that when BP is ≥ 130/80 mm Hg in a patient with previously controlled BP, this is more likely to be caused by day-to-day variation than a true loss of BP control.15Keenan K. Hayen A. Neal B.C. Irwig L. Long term monitoring in patients receiving treatment to lower blood pressure: analysis of data from placebo controlled randomised controlled trial.BMJ. 2009; 338: 1492-1498Crossref Scopus (55) Google Scholar We do not know whether this applies in patients with CKD. Accordingly, in cross-sectional studies, some of the spread of BP readings could be caused by these effects, and we should expect variation around a mean (which would be close to the goal being pursued). In the CRIC Study, the distribution of systolic BP was 127 ± 21.9 mm Hg and diastolic BP 71.4 ± 12.8 mm Hg with a Gaussian distribution skewed slightly to the right, particularly for systolic BP. In individual patients, these effects may lead us to either over- or undertreat. A much better understanding of the innate variation in BP in individuals with CKD is required, as well as better comparison of clinic, home, and ambulatory BP. These findings then could be incorporated into future clinical practice guideline recommendations. A new BP guideline relevant to patients with stages 1-5 CKD worldwide is currently being written by a workgroup commissioned by Kidney Disease: Improving Global Outcomes (KDIGO). However rigorous the development process, the impact of this guideline on patient outcomes will depend largely on proper implementation. As KDIGO recognizes, robust implementation strategies need to be developed hand in hand with any new guideline if patients are to benefit. The observations of Muntner et al5Muntner P. Anderson A. Charleston J. et al.Hypertension awareness, treatment, and control in adults with CKD: results from the Chronic Renal Insufficiency Cohort (CRIC) Study.Am J Kidney Dis. 2010; 55: 441-451Abstract Full Text Full Text PDF PubMed Scopus (246) Google Scholar from the CRIC Study indicate that we still have a great deal of work to do in this respect. Drs Becker and Wheeler are co-chairs of the KDIGO workgroup commissioned to develop a guideline on BP and BP-modifying agents in CKD. Financial Disclosure: The authors declare that they have no relevant financial interests. Hypertension Awareness, Treatment, and Control in Adults With CKD: Results From the Chronic Renal Insufficiency Cohort (CRIC) StudyAmerican Journal of Kidney DiseasesVol. 55Issue 3PreviewA low rate of blood pressure control has been reported in patients with chronic kidney disease (CKD). These data were derived from population-based samples with a low rate of CKD awareness. Full-Text PDF