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Background Prolonged QT interval in hemodialysis patients may be associated with sudden cardiac death, however, few studies examined the longitudinal associations of modifiable factors such as serum and dialysate concentrations of calcium, potassium, and magnesium with corrected QT (QTc) prolongation in incident hemodialysis patients. Methods In 330 in-center hemodialysis participants from the PACE study who were followed up for one year, we examined the associations of predialysis serum electrolytes (total calcium [Ca], corrected Ca [cCa], ionized Ca [iCa], potassium [K], magnesium [Mg]), dialysate (dCa and dK), and serum-to-dialysate gradient measures with QTc interval and prolongation (≥460 ms in women and ≥ 450 ms in men). Results At the first study visit, 47% had QTc prolongation. Lower iCa and K were associated with longer QTc interval independent of potential confounders (QTc difference = 8.55[95% CI: 2.13, 14.97] ms for iCa; QTc difference = 9.89[1.58, 18.20] ms for K). Lower iCa was also associated with a higher risk of QTc prolongation. At 1 year of follow-up, 31% had persistent QTc prolongation. In longitudinal analyses, the associations of iCa and K with QTc interval remained significant, and lower K was associated with a higher risk of QTc prolongation while the association of iCa with QTc prolongation was borderline statistically significant. Serum Mg, dCa or dK, and respective gradients were not associated with QTc interval or prolongation. Conclusion Prolonged QTc is very common in incident hemodialysis participants and persists over follow-up. Ionized Ca and K are consistently inversely associated with QTc prolongation, which suggests closer monitoring for a low calcium or potassium level to mitigate risk. Electronic supplementary material The online version of this article (10.1186/s12882-019-1282-5) contains supplementary material, which is available to authorized users.

Background Apparent treatment-resistant hypertension (aTRH) is a common condition associated with risk of cardiovascular events. However, the risk of cardiovascular mortality associated with aTRH in the US population is unknown. We aimed to assess the risk of cardiovascular disease (CVD) mortality associated with aTRH in the US population. Methods We analyzed data from 6357 adult hypertensive participants of the National Health and Nutrition Examination Survey (1988–1994 and 1999–2010) linked to the National Death Index. Based on presence of uncontrolled hypertension [blood pressure (BP) ≥140/90 mmHg] and the number of antihypertensives prescribed, we classified participants into the following groups: non-aTRH (BP

Background Higher left ventricular mass (LV) strongly predicts cardiovascular mortality in hemodialysis patients. Although several parameters of preload and afterload have been associated with higher LV mass, whether these parameters independently predict LV mass, remains unclear. Methods This study examined a cohort of 391 adults with incident hemodialysis enrolled in the Predictors of Arrhythmic and Cardiovascular Risk in End Stage Renal Disease (PACE) study. The main exposures were systolic and diastolic blood pressure (BP), pulse pressure, arterial stiffness by pulse wave velocity (PWV), volume status estimated by pulmonary pressures using echocardiogram and intradialytic weight gain. The primary outcome was baseline left ventricular mass index (LVMI). Results Each systolic, diastolic blood, and pulse pressure measurement was significantly associated with LVMI by linear regression regardless of dialysis unit BP or non-dialysis day BP measurements. Adjusting for cardiovascular confounders, every 10 mmHg increase in systolic or diastolic BP was significantly associated with higher LVMI (SBP β = 7.26, 95 % CI: 4.30, 10.23; DBP β = 10.05, 95 % CI: 5.06, 15.04), and increased pulse pressure was also associated with higher LVMI (β = 0.71, 95 % CI: 0.29, 1.13). Intradialytic weight gain was also associated with higher LVMI but attenuated effects after adjustment (β = 3.25, 95 % CI: 0.67, 5.83). PWV and pulmonary pressures were not associated with LVMI after multivariable adjustment (β = 0.19, 95 % CI: −1.14, 1.79; and β = 0.10, 95 % CI: −0.51, 0.70, respectively). Simultaneously adjusting for all main exposures demonstrated that higher BP was independently associated with higher LVMI (SBP β = 5.64, 95 % CI: 2.78, 8.49; DBP β = 7.29, 95 % CI: 2.26, 12.31, for every 10 mmHg increase in BP). Conclusions Among a younger and incident hemodialysis population, higher systolic, diastolic, or pulse pressure, regardless of timing with dialysis, is most associated with higher LV mass. Future studies should consider the use of various BP measures in examining the impact of BP on LVM and cardiovascular disease. Findings from such studies could suggest that high BP should be more aggressively treated to promote LVH regression in incident hemodialysis patients. Electronic supplementary material The online version of this article (doi:10.1186/s12882-015-0131-4) contains supplementary material, which is available to authorized users.

Background Sudden cardiac death occurs commonly in the end-stage renal disease population receiving dialysis, with 25% dying of sudden cardiac death over 5 years. Despite this high risk, surprisingly few prospective studies have studied clinical- and dialysis-related risk factors for sudden cardiac death and arrhythmic precursors of sudden cardiac death in end-stage renal disease. Methods/Design We present a brief summary of the risk factors for arrhythmias and sudden cardiac death in persons with end-stage renal disease as the rationale for the Predictors of Arrhythmic and Cardiovascular Risk in End Stage Renal Disease (PACE) study, a prospective cohort study of patients recently initiated on chronic hemodialysis, with the overall goal to understand arrhythmic and sudden cardiac death risk. Participants were screened for eligibility and excluded if they already had a pacemaker or an automatic implantable cardioverter defibrillator. We describe the study aims, design, and data collection of 574 incident hemodialysis participants from the Baltimore region in Maryland, U.S.A.. Participants were recruited from 27 hemodialysis units and underwent detailed clinical, dialysis and cardiovascular evaluation at baseline and follow-up. Cardiovascular phenotyping was conducted on nondialysis days with signal averaged electrocardiogram, echocardiogram, pulse wave velocity, ankle, brachial index, and cardiac computed tomography and angiography conducted at baseline. Participants were followed annually with study visits including electrocardiogram, pulse wave velocity, and ankle brachial index up to 4 years. A biorepository of serum, plasma, DNA, RNA, and nails were collected to study genetic and serologic factors associated with disease. Discussion Studies of modifiable risk factors for sudden cardiac death will help set the stage for clinical trials to test therapies to prevent sudden cardiac death in this high-risk population.

Background There have been major changes in the management of anemia in US hemodialysis patients in recent years. We sought to determine the influence of clinical trial results, safety regulations, and changes in reimbursement policy on practice. Methods We examined indicators of anemia management among incident and prevalent hemodialysis patients from a medium-sized dialysis provider over three time periods: (1) 2004 to 2006 (2) 2007 to 2009, and (3) 2010. Trends across the three time periods were compared using generalized estimating equations. Results Prior to 2007, the median proportion of patients with monthly hemoglobin >12 g/dL for patients on dialysis 0 to 3, 4 to 6 and 7 to 18 months, respectively, was 42%, 55% and 46% declined to 41%, 54%, and 40% after 2007, and declined more sharply in 2010 to 34%, 41%, and 30%. Median weekly Epoeitin alpha doses over the same periods were 18,000, 12,400, and 9,100 units before 2007; remained relatively unchanged from 2007 to 2009; and decreased sharply in the patients 3–6 and 6–18 months on dialysis to 10,200 and 7,800 units, respectively in 2010. Iron doses, serum ferritin, and transferrin saturation levels increased over time with more pronounced increases in 2010. Conclusion Modest changes in anemia management occurred between 2007 and 2009, followed by more dramatic changes in 2010. Studies are needed to examine the effects of declining erythropoietin use and hemoglobin levels and increasing intravenous iron use on quality of life, transplantation rates, infection rates and survival.

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.

Background Evidence is lacking to inform providers’ and patients’ decisions about many common treatment strategies for patients with end stage renal disease (ESRD). Methods/design The DEcIDE Patient Outcomes in ESRD Study is funded by the United States (US) Agency for Health Care Research and Quality to study the comparative effectiveness of: 1) antihypertensive therapies, 2) early versus later initiation of dialysis, and 3) intravenous iron therapies on clinical outcomes in patients with ESRD. Ongoing studies utilize four existing, nationally representative cohorts of patients with ESRD, including (1) the Choices for Healthy Outcomes in Caring for ESRD study (1041 incident dialysis patients recruited from October 1995 to June 1999 with complete outcome ascertainment through 2009), (2) the Dialysis Clinic Inc (45,124 incident dialysis patients initiating and receiving their care from 2003–2010 with complete outcome ascertainment through 2010), (3) the United States Renal Data System (333,308 incident dialysis patients from 2006–2009 with complete outcome ascertainment through 2010), and (4) the Cleveland Clinic Foundation Chronic Kidney Disease Registry (53,399 patients with chronic kidney disease with outcome ascertainment from 2005 through 2009). We ascertain patient reported outcomes (i.e., health-related quality of life), morbidity, and mortality using clinical and administrative data, and data obtained from national death indices. We use advanced statistical methods (e.g., propensity scoring and marginal structural modeling) to account for potential biases of our study designs. All data are de-identified for analyses. The conduct of studies and dissemination of findings are guided by input from Stakeholders in the ESRD community. Discussion The DEcIDE Patient Outcomes in ESRD Study will provide needed evidence regarding the effectiveness of common treatments employed for dialysis patients. Carefully planned dissemination strategies to the ESRD community will enhance studies’ impact on clinical care and patients’ outcomes.

Background This is the first study that has examined non-cardiac incidental findings in research cardiac computed tomography (CT) of hemodialysis patients and their relationship with patient characteristics. Methods We performed a cross-sectional analysis in the Predictors of Arrhythmic and Cardiovascular Events in End-Stage Renal Disease (PACE) study, a prospective cohort study on incident hemodialysis patients. Non-cardiac structures in the cardiac CT scan were reviewed and evaluated. The type and frequencies of non-cardiac incidental CT findings were summarized. Univariate and multivariate logistic regression were performed to analyze the associations between gender, older age, obesity, history of cardiovascular disease (CVD), smoking status, history of chronic pulmonary disease and history of cancer with presence of any incidental CT findings and, separately, pulmonary nodules. Results Among the 260 participants, a total of 229 non-cardiac incidental findings were observed in 145 participants (55.8% of all participants). Of these findings, pulmonary nodules were the most common incidental finding (24.2% of all findings), and 41.3% of them requiring further follow-up imaging per radiology recommendation. Vascular and gastrointestinal findings occurred in 11.8% and 15.3% of participants, respectively. Participants 65 years or older had a higher odds of any incidental findings (Odds Ratio (OR) =2.55; 95% Confidence Intervals (CI) 1.30, 4.99) and pulmonary nodules (OR = 4.80; 95% CI 2.51, 9.18). Prior history of CVD was independently and significantly associated with any incidental findings (OR = 2.00; 95% CI 1.19, 3.40); but not with the presence of pulmonary nodules. Conclusions We demonstrate that the prevalence of incidental findings by cardiac CT scanning is extremely high among patients on hemodialysis. Further investigations to follow-up on the high occurrence of incidental findings during our research study and potentially clinical studies raises important practical, ethical and medico-legal issues that need to be carefully considered in research projects using imaging studies.