Prescription of antihypertensive agents to haemodialysis patients: time trends and associations with patient characteristics, country and survival in the DOPPS

Prognostic impact of guideline-directed medical therapy in patients with heart failure on regular hemodialysis

BACKGROUND

Renin-angiotensin system inhibitor (RASi) and β-blocker provide prognostic benefits as guideline-directed medical therapy (GDMT) in patients with heart failure and reduced ejection fraction (HFrEF). However, there is limited data for the favorable effects in such patients receiving regular hemodialysis. We aimed to evaluate the prognostic impact of RASi and β-blocker in patients with HFrEF who receive regular hemodialysis.

METHODS

In this retrospective, single-center, observational study, from 2110 consecutive patients hospitalized for HF and who survived to discharge, 97 with HFrEF who received regular hemodialysis were included for analysis. They were classified into three groups according to prescribed medication at discharge following index hospitalization: both RASi and β-blocker (Dual-GDMT group: n = 55), either RASi or β-blocker (Mono-GDMT group: n = 34), and neither RASi nor β-blocker (No-GDMT group: n = 8). The primary endpoint was a composite of all-cause death and rehospitalization for heart failure.

RESULTS

The mean age was 66 years and 79% of the patients were men. During the median follow-up of 501 days, the primary endpoint occurred in 43 patients (44%). Kaplan-Meier analysis revealed that the Dual-GDMT group had the lowest rates of the primary endpoint (log-rank test for trend: p < 0.001). Even after adjustment for diverse covariates (multivariate Cox regression), the Dual-GDMT (hazard ratio [HR]: 0.04, 95% confidence interval (CI): 0.005-0.32) and Mono-GDMT (HR: 0.08, 95% CI: 0.01-0.50) groups had better prognoses than the No-GDMT group.

CONCLUSIONS

The prescription of RASi and/or β-blocker was associated with a lower adverse-event rate after discharge in patients with HFrEF who were on regular hemodialysis.

Vascular calcification by conventional X-ray and mortality in a cohort of predominantly African descent hemodialysis patients

BACKGROUND/OBJECTIVE

There is a lack of studies describing the prevalence of vascular calcification (VC) and its association with mortality in maintenance hemodialysis (MHD) patients of African descent. We investigated if a VC score based on the number of calcified vascular beds was associated with mortality in MHD patients.

METHODS

We analyzed data from 211 MHD patients enrolled from January 2010 to January 2011 in the prospective cohort study, "The Prospective Study of the Prognosis of Chronic Hemodialysis Patients (PROHEMO)," developed in Salvador, BA, Brazil. VC was evaluated using radiographs of the hands, abdomen, hip, and chest; the score was calculated by the number of calcified sites as 0 (absence of calcification), 1 (one calcified site), 2 (two sites), 3 (⩾3 sites). We used Cox's regression to estimate the hazard ratio (HR) and 95% confidence interval (CI) of associations between VC and mortality with adjustments for age and comorbidities.

RESULTS

VC was detected in 114 (54.0%) patients; 37 (17.5%) with a VC score = 1; 21 (10%) with VC score = 2 and 56 (26.5%) with VC score = 3. Compared with VC score = 0, the adjusted hazard of death was 2.67 (95% CI: 1.12, 6.33) for patients with VC score = 1; HR = 2.89 (95% CI: 0.95, 7.63) for VC score = 2; and HR = 3.27 (95% CI: 1.47, 7.28) for VC score = 3.

CONCLUSION

The present study in an African descent MHD population provides support for the VC score based on conventional radiography as a prediction tool for the clinical practice. As shown, the VC score was monotonically and independently associated with mortality.

Blood pressure targets and pharmacotherapy for hypertensive patients on hemodialysis

INTRODUCTION

Hypertension is highly prevalent in patients with end-stage kidney disease on hemodialysis and is often not well controlled. Blood pressure (BP) levels before and after hemodialysis have a U-shaped relationship with cardiovascular and all-cause mortality. Although antihypertensive drugs are recommended for patients in whom BP cannot be controlled appropriately by non-pharmacological interventions, large-scale randomized controlled clinical trials are lacking.

AREAS COVERED

The authors review the pharmacotherapy used in hypertensive patients on dialysis, primarily focusing on reports published since 2000. An electronic search of MEDLINE was conducted using relevant key search terms, including 'hypertension', 'pharmacotherapy', 'dialysis', 'kidney disease', and 'antihypertensive drug'. Systematic and narrative reviews and original investigations were retrieved in our research.

EXPERT OPINION

When a drug is administered to patients on dialysis, the comorbidities and characteristics of each drug, including its dialyzability, should be considered. Pharmacological lowering of BP in hypertensive patients on hemodialysis is associated with improvements in mortality. β-blockers should be considered first-line agents and calcium channel blockers as second-line therapy. Renin-angiotensin-aldosterone system inhibitors have not shown superiority to other antihypertensive drugs for patients on hemodialysis.

Fluid overload is associated with use of a higher number of antihypertensive drugs in hemodialysis patients

INTRODUCTION

Hypertension is multifactorial, highly prevalent in the hemodialysis (HD) population and its adequate control requires, in addition to adequate volume management, often the use of multiple antihypertensive drugs. We aimed to describe the use of antihypertensive agents in a group of HD patients and to evaluate the factors associated with the use of multiple classes (≥3) of antihypertensives.

METHODS

We analyzed the baseline data from the HDFit study. Clinically stable patients with HD vintage between 3 and 24 months without any severe mobility limitation were recruited from sites throughout southern Brazil. Fluid status was measured pre-dialysis with the Body Composition Monitor (BCM; Fresenius, Germany). Fluid overload (FO) was considered when the overhydration index (OH) was greater than 7% of extracellular water (OH/ECW > 7%) and overweight was defined as a body mass index (BMI) greater than 25 kg/m² . Prescriptions of antihypertensive drugs were obtained from participants' reports and medical records. Logistic regression was employed to determine factors associated with excessive use of antihypertensive medication (≥3 classes).

FINDINGS

Of 195 studied patients, 171 with complete data were included (70% male, 53 ± 15 years old, 57% of them with FO). Pre-dialysis systolic blood pressure (SBP) was 150 ± 24 mmHg and patients used a median of 2 (1-3) antihypertensive drugs. Vasodilators (20%) were of lowest prevalence, use of other classes varied from 40% to 53%. Sixty-two (36%) subjects used ≥3 classes and presented a higher prevalence of diabetes and FO, lower prevalence of overweight, and higher SBP. In a logistic regression model age, BMI <25 kg/m² , and OH/ECW > 7% were associated with excessive drug use.

DISCUSSION

More than one-third of participants used ≥3 classes of antihypertensive drugs, and it was associated with older age, BMI <25 kg/m² and FO. Strategies that better manage FO may aid better blood pressure control and avoid the use of multiple antihypertensive medications.

Temporal Trends and Factors Associated with Medication Prescription Patterns in Peritoneal Dialysis Patients

INTRODUCTION

Patients on peritoneal dialysis (PD) suffer from a high burden of comorbidities, which are managed with multiple medications. Determinants of prescription patterns are largely unknown in this population. This study assesses temporal changes and factors associated with medication prescription in a nationally representative population of patients on PD under the universal coverage healthcare system in Brazil.

METHODS

Incident patients recruited in the Brazilian Peritoneal Dialysis Study (BRAZPD) from December 2004 to January 2011, stratified by prior hemodialysis (HD) treatment, were included in the analysis. Multivariable logistic regression was used to assess the association between medication prescription and socioeconomic factors. Yearly prevalent cross-sections were calculated to estimate prescription over time.

RESULTS

Medication prescription was in general higher among patients who had previously received HD, compared with those who started renal replacement therapy (RRT) directly on PD. Prescription increased from baseline to 6 months of PD therapy, particularly in those who did not previously receive HD. After accounting for patient characteristics, significant associations were found between socioeconomic factors, geographic region, and medication prescription patterns. Finally, the prescription of all cardioprotective and anemia medications and phosphate binders increased significantly over time.

CONCLUSION

In a PD population under universal coverage in a developing country, there was an increase in drug prescription during the first 6 months on PD, and a trend toward more liberal prescription of medications in later years. Independent from patient characteristics and comorbidities, socioeconomic factors influenced drug prescriptions that likely impact patient outcome, calling for public health action to decrease potential inequities in management of comorbidities in PD patients.

DOPPS data suggest a possible survival benefit of renin angiotensin-aldosterone system inhibitors and other antihypertensive medications for hemodialysis patients

The benefits of renin angiotensin-aldosterone system inhibitors (RAASi) are well-established in the general population, particularly among those with diabetes, congestive heart failure (CHF), or coronary artery disease (CAD). However, conflicting evidence from trials and concerns about hyperkalemia limit RAASi use in hemodialysis patients, relative to other antihypertensive agents, including beta blockers and calcium channel blockers. Therefore, we investigated prescription patterns and associations with mortality for RAASi and other antihypertensive agents using data from the international Dialysis Outcomes and Practice Patterns Study (DOPPS). Cox regression was used to estimate the effect of the prescription of RAASi and other antihypertensive agents at study entry on mortality in 11,421 incident (120 days or less) hemodialysis and 37,124 prevalent (over 120 days) hemodialysis patients from DOPPS phases 2-5 (2002-2015). Over 95% of RAASi were angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. RAASi prevalence was 39% and varied minimally by CHF and CAD. The adjusted hazard ratio for RAASi (vs. no RAASi) was 0.89 (95% confidence interval 0.80-0.99) among incident and 0.94 (0.90-0.99) among prevalent hemodialysis patients, with no convincing evidence of interaction with diabetes, CAD or CHF. Inverse associations with mortality were also observed for beta blockers and calcium channel blockers, and were stronger for angiotensin receptor blockers than angiotensin-converting enzyme inhibitors, but this latter finding requires further study. Thus, our observations suggest a relatively small survival benefit of RAASi and other antihypertensive agents in hemodialysis patients, though randomized prospective studies are needed to potentially change prescribing criteria.

Interactive Effectiveness of Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers or Their Combination on Survival of Hemodialysis Patients

BACKGROUND

Does the use of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers individually or as a combination confer a survival benefit in hemodialysis patients? The answer to this question is yet unclear.

METHODS

We performed a case-cohort study using data from the Mineral and Bone Disorder Outcomes Study for Japanese CKD stage 5D patients (MBD-5D), a 3-year multicenter prospective case-cohort study, including 8,229 hemodialysis patients registered from 86 facilities in Japan. All patients had secondary hyperparathyroidism, a condition defined as a parathyroid hormone level ≥180 pg/mL and/or receiving vitamin D receptor activators. We compared all-cause mortality rates between those receiving ACEI, ARB, and their combination and non-users with interaction testing. We used marginal structural Poisson regression (causal model) to estimate the causal effect and interaction adjusted for possible time-dependent confounding. Cardiovascular mortality was also evaluated.

RESULTS

Among 3,762 randomly sampled subcohort patients, those taking ACEI, ARB, and their combination at baseline accounted for 4.0, 31.6, and 3.8%, respectively. Over 3 years, 1,226 all-cause and 462 cardiovascular deaths occurred. Compared to non-users, ARB-alone users had a lower all-cause mortality rate (adjusted incident rate ratio [aIRR] 0.62, 95% CI 0.50-0.76), whereas ACEI-alone users showed a statistically similar rate (aIRR 1.01, 95% CI 0.57-1.77). On the contrary, combination users had a greater mortality rate (aIRR 2.56, 95% CI 1.22-5.37), showing significant interaction (p = 0.03). Analysis for cardiovascular mortality showed similar results.

CONCLUSION

Among hemodialysis patients with secondary hyperparathyroidism, unlike ACEI use, ARB use was associated with greater survival than non-use. Conversely, combination use was associated with greater mortality. Controlled trials are warranted to verify the causality factors of these associations.

Impact of drugs on intradialytic hypotension: Antihypertensives and vasoconstrictors

Intradialytic hypotension (IDH) is a common complication of hemodialysis and is associated with numerous adverse outcomes including cardiovascular events, inadequate dialysis, loss of vascular access, and death. It is estimated that approximately 20%-30% of all dialysis sessions are affected by IDH. In seeking ways to reduce the occurrence of IDH, dialysis providers often turn to pharmacological approaches: withholding antihypertensive medications prior to hemodialysis or administering vasoconstrictor medications. This review will focus on what is known about the relation between antihypertensive medications and IDH, and summarize studies that have examined the efficacy of vasoconstrictor medications on IDH, including midodrine, arginine vasopressin, and droxidopa. However, there is currently scant evidence that any pharmacological approach is particularly effective in reducing IDH. Additional studies of potential treatments for IDH are needed, and should examine not only hemodynamic effects such as changes in nadir blood pressure during dialysis, but also on patient-centered and clinical outcomes such as symptoms of IDH, quality of life, and cardiovascular events.

Interplay of volume, blood pressure, organ ischemia, residual renal function, and diet: certainties and uncertainties with dialytic management

Extracellular fluid volume overload and its inevitable consequence, hypertension, increases cardiovascular mortality in the long term by leading to left ventricular hypertrophy, heart failure, and ischemic heart disease in dialysis patients. Unlike antihypertensive medications, a strict volume control strategy provides optimal blood pressure control without need for antihypertensive drugs. However, utilization of this strategy has remained limited because of several factors, including the absence of a gold standard method to assess volume status, difficulties in reducing extracellular fluid volume, and safety concerns associated with reduction of extracellular volume. These include intradialytic hypotension; ischemia of heart, brain, and gut; loss of residual renal function; and vascular access thrombosis. Comprehensibly, physicians are hesitant to follow strict volume control policy because of these safety concerns. Current data, however, suggest that a high ultrafiltration rate rather than the reduction in excess volume is related to these complications. Restriction of dietary salt intake, increased frequency, and/or duration of hemodialysis sessions or addition of temporary extra sessions during the process of gradually reducing postdialysis body weight in conventional hemodialysis and discontinuation of antihypertensive medications may prevent these complications. We believe that even if an unwanted effect occurs while gradually reaching euvolemia, this is likely to be counterbalanced by favorable cardiovascular outcomes such as regression of left ventricular hypertrophy, prevention of heart failure, and, ultimately, cardiovascular mortality as a result of the eventual achievement of normal extracellular fluid volume and blood pressure over the long term.

Vitamin D Receptor Activator Use and Cause-specific Death among dialysis Patients: a Nationwide Cohort Study using Coarsened Exact Matching

Vitamin D receptor activators (VDRA) may exert pleiotropic effects on cardiovascular disease, malignancy, and infections among dialysis patients, but recent studies have mainly focused on cardiovascular outcomes. Among 8,675 patients who started dialysis in 2007 and who survived until January 1, 2010, listed in the Renal Data Registry of the Japanese Society for Dialysis Therapy, 5,365 VDRA users were matched to 3,203 non-users based on clinically relevant variables at the end of 2009 using the coarsened exact matching procedure. Until December 31, 2011, a total of 1,128 deaths occurred, of which 468 (42%) were cardiovascular deaths, 229 (20%) were infection-related deaths, and 141 (12%) were malignancy-related deaths. Multivariable survival analyses accounting for intra-region correlation revealed that VDRA use was significantly associated with lower rates of infection- and malignancy-related deaths [subhazard ratio 0.62 (95% CI, 0.52–0.73) and 0.70 (95% CI, 0.50–0.97), respectively] but not with cardiovascular death [subhazard ratio 0.86 (95% CI, 0.72–1.04)]. Future randomized clinical trials with a sufficient sample size and an adequate follow-up period are warranted to test the clinical effectiveness of VDRA on infection and malignancy, rather than cardiovascular disease, among dialysis patients.

The Healthy People 2020 Objectives for Kidney Disease: How Far Have We Come, and Where Do We Need to Go?

The Healthy People 2020 initiative established goals for patients with CKD and ESRD. We assessed United States progress toward some of these key goals. Using data from the Centers for Medicare and Medicaid Services ESRD database, we created yearly cohorts of patients on incident and prevalent dialysis from 2000 to 2013. Change in event rate or proportion change over the study years was modeled using Poisson regression with adjustment for age, race, sex, and primary cause of ESRD. For all-cause mortality in prevalent patients, Healthy People 2020 sought approximately 0.8% relative annual improvement; actual improvement was 2.7%. Improvement was greatest for patients ages 18-44 years old (3.8%; P<0.01 versus 2.8% for ages 65-74 years old) and 2.3% even for patients ages ≥75 years old. For mortality in incident patients, the relative annual decrease was 2.1% overall, a twofold improvement over the goal; mortality decreased nearly twice as much in black as in white patients (3.2% versus 1.8%; P<0.001). Geographic variation was substantial; the relative annual decrease was 0.6% in the Midwest and more than fourfold greater (2.7%) in the South. Cardiovascular mortality in prevalent patients decreased dramatically at 5.0% per year, far exceeding the annual goal of approximately 0.8%; the decrease was greatest in patients ages ≥75 years old (5.5%; P<0.001 versus ages 65-74 years old; 5.1%). The relative annual increase in percentages of patients with a fistula at dialysis initiation was 2.4%, roughly three times the goal; the increase was greater for black than white patients (3.2% versus 2.3%; P<0.01). Adjusted regional differences varied greater than twofold: 2.0% for the South versus 4.1% for the Midwest. Thus, although gains have been substantial, not all groups have benefitted equally. Goal development for Healthy People 2030 should consider changes in goal paradigms, such as tailoring by geographic region and incorporating patient-centered goals.

Antihypertensive Medication Use in Older Patients Transitioning from Chronic Kidney Disease to End-Stage Renal Disease on Dialysis

BACKGROUND AND OBJECTIVES

The transition from CKD to ESRD can be particularly unstable, with high rates of death and hospitalizations. Few studies have examined medication use during this critical period. We examined patterns of antihypertensive medication use from the four quarters before and eight quarters after incident ESRD treated with maintenance dialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used the US Renal Data System to identify patients aged ≥67 years initiating dialysis for ESRD between January 2008 and December 2010 with Medicare Part D and a low-income subsidy. We ascertained the incidence of AKI and hyperkalemia during each quarter on the basis of having at least 1 payment claim for the condition. We used Poisson regression with robust SEMs to formally test for changes in the trend and level of antihypertensive medication use in a series of intervention analyses.

RESULTS

The number of antihypertensive drugs used increased as patients neared ESRD, peaking at an average of 3.4 in the quarter immediately preceding dialysis initiation, then declining to 2.2 medications by 2 years later. Angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker use was stable at approximately 40%, even among patients with coronary disease and systolic heart failure, and did not correlate with AKI or hyperkalemia. Dialysis initiation was associated with a 40% (95% confidence interval, 38% to 43%) lower adjusted level of diuretic use, which continued to decline after ESRD. Three- and four-drug combinations that included a diuretic were most common before ESRD, whereas after ESRD, one- and two-drug β-blocker or calcium-channel blocker-based combinations were most common.

CONCLUSIONS

The use of antihypertensive medications, particularly angiotensin-converting enzyme inhibitor/angiotensin II receptor blockers and diuretics, may be suboptimal during the transition from CKD to ESRD, especially in patients with coronary disease or systolic heart failure. Future studies are needed to identify strategies to increase the appropriate use of antihypertensive medications during this critical transition period.

Controversies and problems of volume control and hypertension in haemodialysis

Extracellular volume overload and hypertension are important contributors to the high risk of cardiovascular mortality in patients undergoing haemodialysis. Hypertension is present in more than 90% of patients at the initiation of haemodialysis and persists in more than two-thirds, despite use of several antihypertensive medications. High blood pressure is a risk factor for the development of left ventricular hypertrophy, heart failure, and mortality, although there are controversies with some study findings showing poor survival with low-but not high-blood pressure. The most frequent cause of hypertension in patients undergoing haemodialysis is volume overload, which is associated with poor cardiovascular outcomes itself independent of blood pressure. Although antihypertensive medications might not be successful to control blood pressure, extracellular volume reduction by persistent ultrafiltration and dietary salt restriction can produce favourable results with good blood pressure control. More frequent or longer haemodialysis can facilitate volume and blood pressure control. However, successful volume and blood pressure control is also possible in patients undergoing conventional haemodialysis.

Factors affecting outcomes in patients reaching end-stage kidney disease worldwide: differences in access to renal replacement therapy, modality use, and haemodialysis practices

More than 2 million people worldwide are being treated for end-stage kidney disease (ESKD). This Series paper provides an overview of incidence, modality use (in-centre haemodialysis, home dialysis, or transplantation), and mortality for patients with ESKD based on national registry data. We also present data from an international cohort study to highlight differences in haemodialysis practices that affect survival and the experience of patients who rely on this therapy, which is both life-sustaining and profoundly disruptive to their quality of life. Data illustrate disparities in access to renal replacement therapy of any kind and in the use of transplantation or home dialysis, both of which are widely considered preferable to in-centre haemodialysis for many patients with ESKD in settings where infrastructure permits. For most patients with ESKD worldwide who are treated with in-centre haemodialysis, overall survival is poor, but longer in some Asian countries than elsewhere in the world, and longer in Europe than in the USA, although this gap has reduced. Commendable haemodialysis practice includes exceptionally high use of surgical vascular access in Japan and in some European countries, and the use of longer or more frequent dialysis sessions in some countries, allowing for more effective volume management. Mortality is especially high soon after ESKD onset, and improved preparation for ESKD is needed including alignment of decision making with the wishes of patients and families.

The CKD Outcomes and Practice Patterns Study (CKDopps): Rationale and Methods

BACKGROUND

Minimizing clinical complications in patients with advanced chronic kidney disease (CKD) and improving the transition to dialysis therapy and transplantation represents a challenge, requiring reliable evidence regarding the effects of CKD care on outcomes.

STUDY DESIGN

The CKD Outcomes and Practice Patterns Study (CKDopps) is a new international prospective cohort study designed to describe and evaluate variation in nephrologist-led CKD practices.

SETTING & PARTICIPANTS

CKDopps is underway in Brazil, France, Germany, Japan, and the United States. Diverse national samples of nephrology clinics are being recruited based on random selection stratified by geographic region and clinic characteristics. CKDopps aims to enroll 12,200 non-dialysis-dependent patients with CKD (75% and 25% with estimated glomerular filtration rates < 30 and 30-<60mL/min/1.73m(2), respectively) to be followed up for 3 to 5 years.

PREDICTORS

Demographic, comorbid condition, laboratory, and treatment-related variables are collected at 6-month intervals; patient-reported data are collected annually and more frequently near the transition to end-stage kidney disease; nephrologist practice surveys are collected annually.

OUTCOMES

Outcomes include mortality, end-stage kidney disease, other clinical events (eg, acute kidney injury, hospitalizations, infections, cardiovascular events, and transplant wait-listing), and patient-reported outcomes.

RESULTS

For the targeted sample size of 12,200 patients and 160 clinics, CKDopps has 80% power to detect HRs of 1.31 for mortality and 1.19 for mortality or transition to end-stage kidney disease.

LIMITATIONS

CKDopps does not capture care provided in settings outside nephrology clinics (eg, primary care) or patients with CKD not receiving medical care.

CONCLUSIONS

CKDopps is designed to characterize nephrology clinic practice variation and identify practices associated with better outcomes, with particular focus on advanced CKD, transition to end-stage kidney disease, and the patient experience. Because data will be collected during routine clinical care in real-world practice, analyses may yield practical readily implementable findings. CKDopps aims to establish a multinational infrastructure for research, collaboration, and ancillary investigation. Additional countries are encouraged to join.

Effect of calcium channels blockers and inhibitors of the renin-angiotensin system on renal outcomes and mortality in patients suffering from chronic kidney disease: systematic review and meta-analysis

BACKGROUND

The renoprotective effect of inhibitors of renin-angiotensin system (RAS) has been identified through placebo-controlled trials. However, the effect of calcium-channel blockers (CCBs) on renal system is still controversial. Our current meta-analysis includes available evidences to compare the effect of dihydropyridine CCBs and ACEIs or ARBs on renal outcomes and mortality. We also further investigate whether CCBs can be used in combination with inhibitors of RAS to improve the prognosis of patients with chronic kidney disease (CKD).

METHODS AND RESULTS

Electronic databases were searched up to July 2012, for clinical randomized controlled trials, assessing the effect of dihydropyridine CCBs on the incidence of end-stage renal disease (ESRD) and all-cause mortality in contrast to ACEIs or ARBs. Eight clinical trials were included containing 25,647 participants. ESRD showed significantly higher frequency with CCBs therapy compared with ACEIs or ARBs therapy, though blood pressure was decreased similarly in both groups in every trial (OR, 1.25; 95% CI, 1.05-1.48; p = 0.01). In contrast, there was no significant difference in the incidence of all-cause mortality between these two groups, though ACEIs or ARBs exhibited better renoprotective effect compared to CCBs (OR, 0.96; 95% CI, 0.89-1.03; p = 0.24).

CONCLUSIONS

CCBs did not increase all-cause mortality incidence in patients with CKD though they displayed weaker renoprotective, compared to ACEIs or ARBs therapy. Our results suggest the combination of a CCB and an ACEI or ARB should be a preferable antihypertensive therapy in patients with CKD, considering their higher effect in decreasing blood pressure and fewer adverse metabolic problems caused.

Successful treatment of hypertension in anuric hemodialysis patients with a direct Renin inhibitor, aliskiren

OBJECTIVE

A direct renin-inhibitor (DRI), aliskiren, was administered to anuric patients to investigate whether it can be a new optional therapy against hypertension in hemodialysis (HD) patients.

PATIENTS

The patients that received aliskiren comprised 8 males and 2 females with a mean ± SD age of 63 ± 8 years (43-72 years). They were exposed to dialysis therapy for 118 ± 73 months (8-251 months), with diabetes mellitus in 4 cases, chronic glomerulonephritis in 4 cases, and other diagnoses in 2 cases.

METHODS

After the plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were measured before an HD session, aliskiren, 150 mg as an initial dose, was administered to the patients. PRA and PAC were also examined a week after initiating aliskiren. The blood pressure (BP) levels at the start of each HD session for a period of 2 weeks (6 HD sessions) were compared between before and after administration of aliskiren. The change of doses in other antihypertensive agents was also counted.

RESULTS

The averaged reduction of mean blood pressure was 4 ± 5 mmHg, and doses of antihypertensives other than aliskiren were reduced in 4 patients. Of the examined parameters, only the reduction rate of PRA x PAC seemed correlated with the BP lowering effect of aliskiren, which was calculated as the sum of the mean BP reduction in mmHg and drug reduction with 1 tablet (capsule)/day considered to be 10 mmHg.

CONCLUSION

A DRI, aliskiren, was effective even in anuric dialysis patients, and monitoring of PRA and PAC was valuable for selecting cases responsive to aliskiren.

Estimation of Drug Effectiveness by Modeling Three Time-dependent Covariates: An Application to Data on Cardioprotective Medications in the Chronic Dialysis Population

In a population of chronic dialysis patients with an extensive burden of cardiovascular disease, estimation of the effectiveness of cardioprotective medication in literature is based on calculation of a hazard ratio comparing hazard of mortality for two groups (with or without drug exposure) measured at a single point in time or through the cumulative metric of proportion of days covered (PDC) on medication. Though both approaches can be modeled in a time-dependent manner using a Cox regression model, we propose a more complete time-dependent metric for evaluating cardioprotective medication efficacy. We consider that drug effectiveness is potentially the result of interactions between three time-dependent covariate measures, current drug usage status (ON versus OFF), proportion of cumulative exposure to drug at a given point in time, and the patient's switching behavior between taking and not taking the medication. We show that modeling of all three of these time-dependent measures illustrates more clearly how varying patterns of drug exposure affect drug effectiveness, which could remain obscured when modeled by the more standard single time-dependent covariate approaches. We propose that understanding the nature and directionality of these interactions will help the biopharmaceutical industry in better estimating drug efficacy.

Antihypertensive medication exposure and cardiovascular outcomes in hemodialysis patients

BACKGROUND/AIMS

Our understanding of the effectiveness of cardioprotective medications in maintenance dialysis patients is based upon drug exposures assessed at a single point in time. We employed a novel, time-dependent approach to modeling medication use over time to examine outcomes in a large national cohort.

METHODS

We linked Medicaid prescription claims with United States Renal Data System registry data and Medicare claims for 52,922 hypertensive maintenance dialysis patients. All-cause mortality and a combined cardiovascular disease (CVD)-endpoint were modeled as functions of exposure to cardioprotective antihypertensive medications (renin angiotensin system antagonists, β-adrenergic blockers, and calcium channel blockers) measured with three time-dependent covariates (weekly exposure status, proportion of prior weeks with exposure, and number of switches in exposure status) and with propensity adjustment.

RESULTS

Current cardioprotective medication exposure status as compared to not exposed was associated with lower adjusted hazard ratios (AHRs) for mortality, though the magnitude depended upon the proportion of prior weeks with medication (duration) and the number of switches between active and non-active use (switches) (AHR range 0.54-0.90). Combined CVD-endpoints depended upon the proportion of weeks on medication: AHR = 1.18 for 10% and AHR = 0.90 for 90% of weeks. Combined CVD-endpoint was also lower for patients with fewer switches.

CONCLUSIONS

Effectiveness depends not only on having a drug available but is tempered by duration and stability of use, likely reflecting variation in clinical stability and patient behavior.

Molecular regulation of the renin-angiotensin system in haemodialysis patients

BACKGROUND

Blockade of the renin-angiotensin system (RAS) exerts beneficial effects in patients with mild-to-moderate chronic kidney disease, yet evidence suggesting a similar benefit in haemodialysis (HD) patients is not available. Furthermore, knowledge of the effects of RAS blockade on systemic RAS components in HD patients is limited. Analysis of the quantity and dynamics of all known peripheral constituents of the RAS may yield important pathomechanistic information of a widespread therapeutic measure in HD patients.

METHODS

Fifty-two HD patients from the following groups were analysed cross-sectionally: patients without RAS blockade (n = 16), angiotensin-converting enzyme inhibitor (ACEi) users (n = 8), angiotensin receptor blocker (ARB) users (n = 11), patients on ACEi plus ARB (dual blockade, n = 8) and anephric patients (n = 9). Ten healthy volunteers served as controls. Angiotensin metabolites were quantified by mass spectrometry.

RESULTS

In general, HD patients showed a broad variability of RAS activity. Patients without RAS blockade displayed angiotensin metabolite patterns similar to healthy controls. ACEi therapy increased plasma Ang 1-10 and Ang 1-7 concentrations, whereas ARB treatment increased both Ang 1-8 and Ang 1-5, while suppressing Ang 1-7 to minimal levels. Dual RAS blockade resulted in high levels of Ang 1-10 and suppressed levels of other angiotensins. Anephric patients were completely devoid of detectable levels of circulating angiotensins.

CONCLUSION

In HD patients, the activity status of the systemic RAS is highly distorted with the emergence of crucial angiotensin metabolites upon distinct RAS blockade. The characterization of molecular RAS patterns associated with specific RAS interfering therapies may help to individualize future clinical studies and therapies.

Medication among patients with type 1 diabetes and predialytic renal disease

AIMS

To examine use and changes of medication in the three years before start of chronic renal replacement therapy (RRT) among patients with type 1 diabetes, and the association between predialytic medication and survival on RRT.

METHODS

We recorded medication of 496 patients with type 1 diabetes before and after start of RRT in 2000-2006 and followed up until death or end of 2009. Data were retrieved from the Finnish Registry for Kidney Diseases and from the FinDM diabetes database. We evaluated the use of renin-angiotensin system (RAS) blockers, calcium channel blockers, β-blockers, statins, vitamin D, erythropoiesis-stimulating agents, and phosphate binders over three years. The association between predialytic medication and survival was assessed using Cox proportional hazards regression.

RESULTS

Medication increased markedly with progressing renal insufficiency. Almost 70% of the patients used calcium channel blockers and β-blockers before initiating RRT. Use of calcium channel blockers (RR 0.72, 95% CI 0.53-0.95) and vitamin D (RR 0.70, 95% CI 0.52-0.94) at start of RRT were associated with better survival when adjusted for age and sex, but after further adjustment the association lost statistical significance.

CONCLUSIONS

Among type 1 diabetes patients in the predialysis phase, use of medication is abundant. Use of medication appears to keep patients at an equal survival level to those without the same medication. However, due to the observational nature of our study, conclusions regarding the effect of medication on survival must be made with caution.

Patterns in blood pressure medication use in US incident dialysis patients over the first 6 months

BACKGROUND

Several observational studies have evaluated the effect of a single exposure window with blood pressure (BP) medications on outcomes in incident dialysis patients, but whether BP medication prescription patterns remain stable or a single exposure window design is adequate to evaluate effect on outcomes is unclear.

METHODS

We described patterns of BP medication prescription over 6 months after dialysis initiation in hemodialysis and peritoneal dialysis patients, stratified by cardiovascular comorbidity, diabetes, and other patient characteristics. The cohort included 13,072 adult patients (12,159 hemodialysis, 913 peritoneal dialysis) who initiated dialysis in Dialysis Clinic, Inc., facilities January 1, 2003-June 30, 2008, and remained on the original modality for at least 6 months. We evaluated monthly patterns in BP medication prescription over 6 months and at 12 and 24 months after initiation.

RESULTS

Prescription patterns varied by dialysis modality over the first 6 months; substantial proportions of patients with prescriptions for beta-blockers, renin angiotensin system agents, and dihydropyridine calcium channel blockers in month 6 no longer had prescriptions for these medications by month 24. Prescription of specific medication classes varied by comorbidity, race/ethnicity, and age, but little by sex. The mean number of medications was 2.5 at month 6 in hemodialysis and peritoneal dialysis cohorts.

CONCLUSIONS

This study evaluates BP medication patterns in both hemodialysis and peritoneal dialysis patients over the first 6 months of dialysis. Our findings highlight the challenges of assessing comparative effectiveness of a single BP medication class in dialysis patients. Longitudinal designs should be used to account for changes in BP medication management over time, and designs that incorporate common combinations should be considered.

Impact of race on cumulative exposure to antihypertensive medications in dialysis

BACKGROUND

Racial minorities typically have less exposure than non-minorities to antihypertensive medications across an array of cardiovascular conditions in the general population. However, cumulative exposure has not been investigated in dialysis patients.

METHODS

In a longitudinal analysis of 38,381 hypertensive dialysis patients, prescription drug data from Medicaid was linked to Medicare data contained in United States Renal Data System core data, creating a national cohort of dialysis patients dually eligible for Medicare and Medicaid services. The proportion of days covered (PDC) was calculated to determine cumulative exposure to angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), β-blockers, and calcium-channel blockers (CCDs). The factors associated with use of these medications were modeled through weighted linear regression, with derivation of the adjusted odds ratios (AORs) for exposure.

RESULTS

Relative to non-Hispanic Caucasians, African-American, Hispanic, or Other race/ethnicity were significantly associated with less exposure to β-blockers (AOR 0.56-0.69, P < 0.001 in each case) and CCBs (AOR 0.84-0.85, P < 0.001 in each case); African-American race and Hispanic ethnicity had AORs of 0.78 and 0.73 for ACEIs and ARBs, respectively (P < 0.001 in both cases). Collectively, the odds of exposure to each class of medication for minorities was about three-quarters of that for Caucasians.

CONCLUSIONS

Given that dually Medicare-and-Medicaid-eligible dialysis patients have insurance coverage for prescription medications as well as regular contact with health care providers, differences by race in exposure to antihypertensive medications should with time be minimal among patients who are candidates for these drugs. The causes of differences by race in exposure to antihypertensive medications over the course of time should be further examined.

Burden and management of chronic kidney disease in Japan: systematic review of the literature

Background

Chronic kidney disease (CKD) is a common disorder with increasing prevalence worldwide. This systematic literature review aims to provide insights specific to Japan regarding the burden and treatment of CKD.

Methods

We reviewed English and Japanese language publications from the last 10 years, reporting economic, clinical, humanistic, and epidemiologic outcomes, as well as treatment patterns and guidelines on CKD in Japan.

Results

This review identified 85 relevant articles. The prevalence of CKD was found to have increased in Japan, attributable to multiple factors, including better survival on dialysis therapy and a growing elderly population. Risk factors for disease progression differed depending on CKD stage, with proteinuria, smoking, hypertension, and low levels of high-density lipoprotein commonly associated with progression in patients with stage 1 and 2 disease. Serum albumin levels and hemoglobin were the most sensitive variables to progression in patients with stage 3 and 5 disease, respectively. Economic data were limited. Increased costs were associated with disease progression, and with peritoneal dialysis as compared with either hemodialysis or combination therapy (hemodialysis + peritoneal dialysis) treatment options. Pharmacological treatments were found potentially to improve quality of life and result in cost savings. We found no reports of treatment patterns in patients with early-stage CKD; however, calcium channel blockers were the most commonly prescribed antihypertensive agents in hemodialysis patients. Treatment guidelines focused on anemia management related to dialysis and recommendations for peritoneal dialysis treatment and preventative measures. Few studies focused on humanistic burden in Japanese patients; Japanese patients reported greater disease burden but better physical functioning compared with US and European patients.

Conclusion

A dearth of evidence regarding the earlier stages of kidney disease presents an incomplete picture of CKD disease burden in Japan. Further research is needed to gain additional insight into CKD in Japan.

Geographic variation in HMG-CoA reductase inhibitor use in dialysis patients

BACKGROUND

Despite uncertainty about their effectiveness in chronic dialysis patients, statin use has increased in recent years. Little is known about the demographic, clinical, and geographic factors associated with statin exposure in end-stage renal disease (ESRD) patients.

OBJECTIVE

To analyze the demographic, clinical, and geographic factors associated with use of statins among chronic dialysis patients.

DESIGN

Cross-sectional analysis.

SETTING

Prevalent dialysis patients across the U.S.

PARTICIPANTS

55,573 chronic dialysis patients who were dually eligible for Medicaid and Medicare services during the last four months of 2005.

METHODS

Using Medicaid prescription drug claims and United States Renal Data System core data, we examined demographics, comorbid conditions, and state of residence using hierarchical logistic regression models to determine their associations with statin use.

INTERVENTION

Prescription for a statin.

OUTCOME MEASURES

Factors associated with a prescription for a statin.

RESULTS

Statin exposure was significantly associated with older age, female sex, Caucasian (versus African-American) race, body mass index, use of self-care dialysis, diabetes, and comorbidity burden. Moreover, there was substantial state-by-state variation in statin use, with a greater than 2.3-fold difference in adjusted odds ratios between the highest- and lowest-prescribing states.

CONCLUSIONS

Among publicly insured chronic dialysis patients, there were marked differences between states in the use of HMG-CoA reductase inhibitors above and beyond patient characteristics. This suggests substantial clinical uncertainty about the utility of these medications. Understanding how such regional variations impact patient care in this high-risk population is an important focus for future work.

Prognostic significance of left ventricular hypertrophy observed at dialysis initiation depends on the pre-dialysis use of erythropoiesis-stimulating agents

BACKGROUND

Recent experimental studies suggest that erythropoietin promotes beneficial myocardial remodeling during left ventricular hypertrophy (LVH); however, such compensatory capacity may be limited due to insufficient erythropoietin production in chronic kidney disease patients. Thus, this study aimed to explore the effect of pre-dialysis erythropoiesis-stimulating agent (ESA) use on the prognostic significance of LVH in dialyzed patients.

METHODS

This retrospective study included 404 consecutive patients who started dialysis between 2001 and 2009. The interaction of ESA with the association between left ventricular mass index (LVMI) observed at dialysis initiation and all-cause and cardiovascular mortality was analyzed at the end of 2010 using the Cox model.

RESULTS

During a median follow-up of 36.5 months, 164 patients died, 31 of them from heart failure. The frequency of pre-dialysis ESA use was 58.7 % and median LVMI was 160.3 g/m(2). Of interest, patients with the lowest tertile of LVMI had worse survival compared with those with each subsequent tertile. LVMI was inversely associated with all-cause mortality [hazard ratio (HR) 0.991, 95 % confidence interval (CI) 0.988-0.995, P = 0.000] after extensive adjustment including ejection fraction, whereas the prognostic value of LVMI for cardiovascular mortality was dependent on pre-dialysis ESA use [adjusted HR 1.010, 95 % CI 0.999-1.020, P = 0.065 for pre-dialysis ESA(+) and 0.978, 95 % CI 0.967-0.989, P = 0.000 for pre-dialysis ESA(-), respectively].

CONCLUSIONS

Our results suggest that reverse epidemiology may exist between LVH and mortality and that pre-dialysis ESA use may modify the prognostic significance of LVH observed at dialysis initiation for cardiovascular mortality in dialyzed patients.

Blood pressure and blood volume: acute and chronic considerations in hemodialysis

Hypertension is highly prevalent yet poorly controlled in the majority of dialysis patients and represents a significant burden of disease, with rates of morbidity and mortality greater than those in the general population. In dialysis, blood volume plays a critical role in the pathogenesis of hypertension, with expansion of extracellular volume increasingly recognized as an independent risk factor for morbidity and mortality. Within the current paradigm of dialysis prescription the majority of patients remain chronically volume expanded. However, management of blood pressure and volume state is difficult for clinicians with a paucity of randomized evidence adding to the complexity of nonlinear morbidity and mortality associations. With dialysis itself as a significant cardiac stressor, control of volume state is critical to minimize intradialytic hemodynamic instability, aid in preservation of cardiac anatomy and prevent progression to cardiovascular morbidity and mortality. This review explores the relationship of blood volume to blood pressure and potential targets for management in this at risk population.

Instrumental variable analysis

The main advantage of the randomized controlled trial (RCT) is the random assignment of treatment that prevents selection by prognosis. Nevertheless, only few RCTs can be performed given their high cost and the difficulties in conducting such studies. Therefore, several analytical methods for removing the effects of selection bias in observational studies have been proposed. The first aim of this paper is to compare three of those methods: the multivariable risk adjustment method, the propensity score risk adjustment method, and the instrumental variable method. The second aim is to compare the results from observational studies using the instrumental variable method with those from RCTs aiming to answer the same study question.

Modifiable practices associated with sudden death among hemodialysis patients in the Dialysis Outcomes and Practice Patterns Study

BACKGROUND AND OBJECTIVES

Sudden death is common in hemodialysis patients, but whether modifiable practices affect the risk of sudden death remains unclear.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study analyzed 37,765 participants in 12 countries in the Dialysis Outcomes and Practice Patterns Study to explore the association of the following practices with sudden death (due to cardiac arrhythmia, cardiac arrest, and/or hyperkalemia): treatment time [TT] <210 minutes, Kt/V <1.2, ultrafiltration volume >5.7% of postdialysis weight, low dialysate potassium [K(D) <3]), and prescription of Q wave/T wave interval-prolonging drugs. Cox regression was used to estimate effects on mortality, adjusting for potential confounders. An instrumental variable approach was used to further control for unmeasured patient-level confounding.

RESULTS

There were 9046 deaths, 26% of which were sudden (crude mortality rate, 15.3/100 patient-years; median follow-up, 1.59 years). Associations with sudden death included hazard ratios of 1.13 for short TT, 1.15 for large ultrafiltration volume, and 1.10 for low Kt/V. Compared with K(D) ≥3 mEq/L, the sudden death rate was higher for K(D) ≤1.5 and K(D)=2-2.5 mEq/L. The instrumental variable approach yielded generally consistent findings. The sudden death rate was elevated for patients taking amiodarone, but not other Q wave/T wave interval-prolonging drugs.

CONCLUSIONS

This study identified modifiable dialysis practices associated with higher risk of sudden death, including short TT, large ultrafiltration volume, and low K(D). Because K(D) <3 mEq/L is common and easy to change, K(D) tailoring may prevent some sudden deaths. This hypothesis merits testing in clinical trials.

Utilization and costs of cardiovascular disease medications in dialysis patients in Medicare Part D

BACKGROUND

Cardiovascular disease (CVD) is a major source of mortality and morbidity in dialysis patients. Population-level descriptions of CVD medication use are lacking in this population.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Adult dialysis patients in the United States, alive on December 31, 2006, with Medicare Parts A and B and enrollment in Medicare Part D continuously in 2007.

PREDICTOR

CVDs and demographic characteristics.

OUTCOME

≥1 prescription fill during follow-up (2007).

MEASUREMENTS

Average out-of-pocket costs per user per month and average total drug costs per member per month were calculated.

RESULTS

Of 225,635 dialysis patients who met inclusion criteria during the entry period, 70% (n = 158,702) had continuous Part D coverage during follow-up. Of these, 76% received the low-income subsidy. β-Blockers were the most commonly used CVD medication (64%), followed by renin-angiotensin system inhibitors (52%), calcium channel blockers (51%), lipid-lowering agents (44%), and α-agonists (23%). Use varied by demographics, geographic region, and low-income subsidy status. For CVD medications, mean out-of-pocket costs per user per month were $3.44 and $49.59 and mean total costs per member per month were $124.02 and $110.32 for patients with and without the low-income subsidy, respectively.

LIMITATIONS

Information was available for only filled prescriptions under the Part D benefit; information for clinical contraindications was lacking, information for over-the-counter medications was unavailable, and medication adherence and persistence were not examined.

CONCLUSIONS

Most Medicare dialysis patients in 2007 were enrolled in Part D, and most enrollees received the low-income subsidy. β-Blockers were the most used CVD medication. Total costs of CVD medications were modestly higher for low-income subsidy patients, but out-of-pocket costs were much higher for patients not receiving the subsidy. Further study is warranted to delineate sources of variation in the use and costs of CVD medications across subgroups.

Home systolic blood pressure on the morning of dialysis days has prognostic impact for hypertensive hemodialysis patients

Background

Hypertension is a leading cause of cardiovascular (CV) disease in the general population. Although hypertension is very common in maintenance hemodialysis (HD) patients, adequate blood pressure (BP) values and measurement timing have not been defined.

Methods

A total of 49 hypertensive HD patients were recruited. Average age was 63 ± 11 years, and duration of dialysis therapy was 6.2 ± 4.2 years. Dialysis unit BPs and various types of home BPs were separately measured, and which BPs were the most critical markers in evaluating the effect of hypertension on left ventricular hypertrophy and CV events was investigated.

Results

Predialysis systolic BPs were not correlated with any home BPs. Left ventricular mass index (LVMI) had a significant positive correlation with home BPs, especially morning systolic BPs on HD days (P < 0.01) and non-HD days (P < 0.05), on univariate and multivariate analysis. In contrast, predialysis BPs did not correlate with LVMI. During the follow-up period (47 ± 18 months), it was demonstrated that diabetes and home BPs, especially systolic BPs on the morning of HD days, were significant predictors of CV events on multivariate Cox regression analysis. A 10 mmHg increase in BP had a significantly elevated relative risk for CV events.

Conclusions

Home BP, especially systolic BPs in the morning on HD days, can provide pivotal information for management of HD patients.

Angiotensin-converting enzyme inhibitors and cardiovascular outcomes in patients on maintenance hemodialysis

BACKGROUND

Persons with end-stage renal disease (ESRD) on hemodialysis carry an exceptionally high burden of cardiovascular disease. Angiotensin-converting enzyme inhibitors (ACEIs) are recommended for patients on dialysis, but there are few data regarding their effectiveness in ESRD.

METHODS

We conducted a secondary analysis of results of the HEMO study, a randomized trial of dialysis dose and membrane flux in patients on maintenance hemodialysis. We focused on the nonrandomized exposure of ACEI use, using proportional hazards regression and a propensity score analysis. The primary outcome was all-cause mortality. Secondary outcomes examined in the present analysis were cardiovascular hospitalization, heart failure hospitalization, and the composite outcomes of death or cardiovascular hospitalization and death or heart failure hospitalization.

RESULTS

In multivariable-adjusted analyses, there were no significant associations among ACEI use and mortality (hazard ratio 0.97, 95% CI 0.82-1.14), cardiovascular hospitalization, and either composite outcome. Angiotensin-converting enzyme inhibitor use was associated with a higher risk of heart failure hospitalization (hazard ratio 1.41, 95% CI 1.11-1.80). In the propensity score-matched cohort, ACEI use was not significantly associated with any outcomes, including heart failure hospitalization.

CONCLUSIONS

In a well-characterized cohort of patients on maintenance hemodialysis, ACEI use was not significantly associated with mortality or cardiovascular morbidity. The higher risk of heart failure hospitalization associated with ACEI use may not only reflect residual confounding but also highlights gaps in evidence when applying treatments proven effective in the general population to patients with ESRD. Our results underscore the need for definitive trials in ESRD to inform the treatment of cardiovascular disease.

International differences in hemodialysis delivery and their influence on outcomes

There are many variations in the delivery of hemodialysis. These variations include components of conventional dialysis, such as membrane type, dialysis dose, and session duration. In addition, alternative approaches to dialysis, such as hemodiafiltration, nocturnal hemodialysis, and short daily hemodialysis, also may be considered. For some of these practice variations, data exist to support one approach over another (eg, fistulas rather than grafts and catheters), but for many, no such data exist. Very few practice variations have been examined in randomized trials, and we are reliant predominantly on observational data. This review examines some practice variations in hemodialysis delivery, attempting to highlight which of these may be appropriate to consider when optimizing dialysis delivery in the clinic.

Geographic variation in cardioprotective antihypertensive medication usage in dialysis patients

BACKGROUND

Despite their high risk of adverse cardiac outcomes, persons on long-term dialysis therapy have had lower use of antihypertensive medications with cardioprotective properties, such as angiotensin-converting enzyme (ACE) inhibitors/angiotensin receptor blockers (ARBs), β-blockers, and calcium channel blockers, than might be expected. We constructed a novel database that permits detailed exploration into the demographic, clinical, and geographic factors associated with the use of these agents in hypertensive long-term dialysis patients.

STUDY DESIGN

National cross-sectional retrospective analysis linking Medicaid prescription drug claims with US Renal Data System core data.

SETTING & PARTICIPANTS

48,882 hypertensive long-term dialysis patients who were dually eligible for Medicaid and Medicare services in 2005.

FACTORS

Demographics, comorbid conditions, functional status, and state of residence.

OUTCOMES

Prevalence of cardioprotective antihypertensive agents in Medicaid pharmacy claims and state-specific observed to expected ORs of medication exposure.

MEASUREMENTS

Factors associated with medication use were modeled using multilevel logistic regression models.

RESULTS

In multivariable analyses, cardioprotective antihypertensive medication exposure was associated significantly with younger age, female sex, nonwhite race, intact functional status, and use of in-center hemodialysis. Diabetes was associated with a statistically significant 28% higher odds of ACE-inhibitor/ARB use, but congestive heart failure was associated with only a 9% increase in the odds of β-blocker use and no increase in ACE-inhibitor/ARB use. There was substantial state-by-state variation in the use of all classes of agents, with a greater than 2.9-fold difference in adjusted-rate ORs between the highest and lowest prescribing states for ACE inhibitors/ARBs and a 3.6-fold difference for β-blockers.

LIMITATIONS

Limited generalizability beyond study population.

CONCLUSIONS

In publicly insured long-term dialysis patients with hypertension, there were marked differences in use rates by state, potentially due in part to differences in Medicaid benefits. However, geographic characteristics also were associated with exposure, suggesting clinical uncertainty about the utility of these medications.

Treatment of heart failure in long-term dialysis patients: a reappraisal

Heart failure is one of the most frequent cardiac complications in patients with end-stage renal disease receiving long-term hemodialysis or peritoneal dialysis and is associated strongly with a poor prognosis. Despite the significant morbidity and mortality associated with heart failure, there are very limited therapeutic options proved to prevent and treat heart failure in dialysis patients. This limitation largely reflects the paucity of adequately powered prospective randomized clinical trials that have examined the efficacy of different therapeutic options in long-term dialysis patients with heart failure. In this article, the second in a series discussing the management of heart failure in dialysis patients, current therapeutic options for heart failure in the maintenance dialysis population are reviewed and potential novel therapeutic options are discussed.

Perceived barriers to guidelines in peritoneal dialysis

BACKGROUND

Little is known regarding barriers to guideline adherence in the nephrology community. We set out to identify perceived barriers to evidence-based medicine (EBM) and measurement of continuous quality indicators (CQI) in an international cohort of peritoneal dialysis (PD) practitioners.

METHODS

Subscribers to an online nephrology education site (Nephrology Now) were invited to participate in an online survey. Nephrology Now is a non-profit, monthly mailing list that highlights clinically relevant articles in nephrology. Four hundred and seventy-five physicians supplying PD care participated in an online survey assessing their use of EBM and CQI in their PD practice. Ordinal logistic regression was utilized to determine relationships between baseline characteristics and EBM and CQI practices.

RESULTS

The majority of physicians were nephrologists (89.7%), and 50.4% worked in an academic centre. Respondents were from the following geographic regions: 13.5% Canadian, 24% American, 23.8% European, 4.4% Australian, 5.3% South American, 10.7% African and 12.2% Asian. Adherence to PD clinical practice guidelines were generally strong; however, lower adherence was associated with countries with lower healthcare expenditure, not using personal digital assistant (PDA), the longer the physician had been practising and smaller (< 20 patients per centre) PD practice.

CONCLUSIONS

International variation in guideline adherence may be influenced by a country's healthcare expenditure, physician's PDA use and experience, and size of PD practice which may impact future guideline development and implementation.