CKD Progression and Mortality among Hispanics and Non-Hispanics

Although recommended approaches to CKD management are achieved less often in Hispanics than in non-Hispanics, whether long-term outcomes differ between these groups is unclear. In a prospective longitudinal analysis of participants enrolled into the Chronic Renal Insufficiency Cohort (CRIC) and Hispanic-CRIC Studies, we used Cox proportional hazards models to determine the association between race/ethnicity, CKD progression (50% eGFR loss or incident ESRD), incident ESRD, and all-cause mortality, and linear mixed-effects models to assess differences in eGFR slope. Among 3785 participants, 13% were Hispanic, 43% were non-Hispanic white (NHW), and 44% were non-Hispanic black (NHB). Over a median follow-up of 5.1 years for Hispanics and 6.8 years for non-Hispanics, 27.6% of all participants had CKD progression, 21.3% reached incident ESRD, and 18.3% died. Hispanics had significantly higher rates of CKD progression, incident ESRD, and mean annual decline in eGFR than did NHW (P<0.05) but not NHB. Hispanics had a mortality rate similar to that of NHW but lower than that of NHB (P<0.05). In adjusted analyses, the risk of CKD progression did not differ between Hispanics and NHW or NHB. However, among nondiabetic participants, compared with NHB, Hispanics had a lower risk of CKD progression (hazard ratio, 0.61; 95% confidence interval, 0.39 to 0.95) and incident ESRD (hazard ratio, 0.50; 95% confidence interval, 0.30 to 0.84). At higher levels of urine protein, Hispanics had a significantly lower risk of mortality than did non-Hispanics (P<0.05). Thus, important differences in CKD progression and mortality exist between Hispanics and non-Hispanics and may be affected by proteinuria and diabetes.

Racial/ethnic differences in atrial fibrillation symptoms, treatment patterns, and outcomes: Insights from Outcomes Registry for Better Informed Treatment for Atrial Fibrillation Registry

BACKGROUND

Significant racial/ethnic differences exist in the incidence of atrial fibrillation (AF). However, less is known about racial/ethnic differences in quality of life (QoL), treatment, and outcomes associated with AF.

METHODS

Using data from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation, we compared clinical characteristics, QoL, management strategies, and long-term outcomes associated with AF among various racial/ethnic groups.

RESULTS

We analyzed 9,542 participants with AF (mean age 74 ± 11 years, 43% women, 91% white, 5% black, 4% Hispanic) from 174 centers. Compared with AF patients identified as white race, patients identified as Hispanic ethnicity and those identified as black race were younger, were more often women, and had more cardiac and noncardiac comorbidities. Black patients were more symptomatic with worse QoL and were less likely to be treated with a rhythm control strategy than other racial/ethnic groups. There were no significant racial/ethnic differences in CHA2DS2-VASc stroke or ATRIA bleeding risk scores and rates of oral anticoagulation use were similar. However, racial and ethnic minority populations treated with warfarin spent a lower median time in therapeutic range of international normalized ratio (59% blacks vs 68% whites vs 62% Hispanics, P < .0001). There was no difference in long-term outcomes associated with AF between the 3 groups at a median follow-up of 2.1 years.

CONCLUSION

Relative to white and Hispanic patients, black patients with AF had more symptoms, were less likely to receive rhythm control interventions, and had lower quality of warfarin management. Despite these differences, clinical events at 2 years were similar by race and ethnicity.

High-sensitivity cardiac troponin I and incident coronary heart disease among asymptomatic older adults

OBJECTIVE

High-sensitivity cardiac troponin I (hs-cTnI) is a novel biomarker of myocardial injury and ischaemia. Our objective was to ascertain correlates of hs-cTnI and its incremental prognostic utility for incident coronary heart disease (CHD) among older asymptomatic subjects.

METHODS

We performed a cohort study among 1135 asymptomatic control participants in the ADVANCE (Atherosclerotic Disease, VAscular FunctioN and GenetiC Epidemiology) study at Kaiser Permanente Northern California and Stanford University, with follow-up through 31 December 2014. Hs-cTnI was measured in stored baseline (2002-2004) serum samples.

RESULTS

After a median follow-up of 11.3 years, 164 CHD events were documented. The most significant correlates of hs-cTnI were black race, body mass index, hypertension, LDL cholesterol and estimated glomerular filtration rate (eGFR) (R(2)=0.16) After adjustment for race/ethnicity, education level, diabetes status, ATP-III Framingham risk score (FRS), C reactive protein and eGFR, each 1 SD increment of log-transformed Hs-cTnI was associated with 1.11 (95% CI 1.01 to 1.23, p=0.04) increased hazard of CHD. The c-statistic increased to 0.70 from 0.68 (p=0.16) and the category-based net reclassification index was 18% (95% CI 8% to 30%) after adding hs-cTnI to the model containing the ATP-III FRS.

CONCLUSIONS

Hs-cTnI conveys incremental prognostic information for incident CHD among asymptomatic older adults.

Mild prolonged chronic hyponatremia and risk of hip fracture in the elderly

BACKGROUND

Hip fractures are among the most serious bone fractures in the elderly, producing significant morbidity and mortality. Several observational studies have found that mild hyponatremia can adversely affect bone, with fractures occurring as a potential complication. We examined if there is an independent association between prolonged chronic hyponatremia (>90 days duration) and risk of hip fracture in the elderly.

METHODS

We performed a retrospective cohort study in adults >60 years of age from a prepaid health maintenance organization who had two or more measurements of plasma sodium between 2005 and 2012. The incidence of hip fractures was assessed in a very restrictive population: subjects with prolonged chronic hyponatremia, defined as plasma sodium values <135 mmol/L, lasting >90 days. Multivariable Cox regression was performed to determine the hazard ratio (HR) for hip fracture risk associated with prolonged chronic hyponatremia after adjustment for the propensity to have hyponatremia, fracture risk factors and relevant baseline characteristics.

RESULTS

Among 31 527 eligible patients, only 228 (0.9%) had prolonged chronic hyponatremia. Mean plasma sodium was 132 ± 5 mmol/L in hyponatremic patients and 139 ± 3 mmol/L in normonatremic patients (P < 0.001). The absolute risk for hip fracture was 7/282 in patients with prolonged chronic hyponatremia and 411/313 299 in normonatremic patients. Hyponatremic patients had a substantially elevated rate of hip fracture [adjusted HR 4.52 (95% CI 2.14-9.6)], which was even higher in those with moderate hyponatremia (<130 mmol/L) [adjusted HR 7.61 (95% CI 2.8-20.5)].

CONCLUSION

Mild prolonged chronic hyponatremia is independently associated with hip fracture risk in the elderly population, although the absolute risk is low. However, proof that correcting hyponatremia will result in a reduction of hip fractures is lacking.

Cognitive Impairment and Progression of CKD

BACKGROUND

Cognitive impairment is common among patients with chronic kidney disease (CKD); however, its prognostic significance is unclear. We assessed the independent association between cognitive impairment and CKD progression in adults with mild to moderate CKD.

STUDY DESIGN

Prospective cohort.

SETTING & PARTICIPANTS

Adults with CKD participating in the CRIC (Chronic Renal Insufficiency Cohort) Study. Mean age of the sample was 57.7±11.0 years and mean estimated glomerular filtration rate (eGFR) was 45.0±16.9mL/min/1.73m(2).

PREDICTOR

Cognitive function was assessed with the Modified Mini-Mental State Examination at study entry. A subset of participants 55 years and older underwent 5 additional cognitive tests assessing different domains. Cognitive impairment was defined as a score > 1 SD below the mean score on each test. Covariates included demographics, kidney function, comorbid conditions, and medications.

OUTCOMES

Incident end-stage renal disease (ESRD) and incident ESRD or 50% decline in baseline eGFR.

RESULTS

In 3,883 CRIC participants, 524 (13.5%) had cognitive impairment at baseline. During a median 6.1 years of follow-up, 813 developed ESRD and 1,062 developed ESRD or a ≥50% reduction in eGFR. There was no significant association between cognitive impairment and risk for ESRD (HR, 1.07; 95% CI, 0.87-1.30) or the composite of ESRD or 50% reduction in eGFR (HR, 1.06; 95% CI, 0.89-1.27). Similarly, there was no association between cognitive impairment and the joint outcome of death, ESRD, or 50% reduction in eGFR (HR, 1.06; 95% CI, 0.91-1.23). Among CRIC participants who underwent additional cognitive testing, we found no consistent association between impairment in specific cognitive domains and risk for CKD progression in adjusted analyses.

LIMITATIONS

Unmeasured potential confounders, single measure of cognition for younger participants.

CONCLUSIONS

Among adults with CKD, cognitive impairment is not associated with excess risk for CKD progression after accounting for traditional risk factors.

Association of Age to Mortality and Repeat Revascularization in End-Stage Renal Disease Patients: Implications for Clinicians and Future Health Policies

BACKGROUND

The clinical effects of age occur over an age continuum, yet age as a primary predictor is often analyzed using arbitrary age cut-points.

OBJECTIVE

To assess whether transformation of a continuous variable such as age using a spline function can uncover nonlinear associations between age and cardiovascular outcomes.

DESIGN

Observational retrospective cohort study in 1015 Kaiser Permanente Northern California patients with end-stage renal disease after index coronary revascularization. Age, the primary predictor, was modeled by 5 different techniques: 1) dichotomized at 65 years or older; 2) at 80 years or older (as a sensitivity analysis); 3) categorized as younger than 55 years (reference), 55 to 64, 65 to 74, and 75 years or older; 4) linear (every 5 years) variable; and 5) nonlinear by transformation into a cubic spline. Age categories were changed in a sensitivity analysis.

MAIN OUTCOME MEASURES

Primary and secondary outcomes were all-cause mortality and repeat revascularization, respectively.

RESULTS

Graphical assessment demonstrated that age dichotomized at either 65 years and older or 80 years and older led to loss of information. Categorized age underestimated or overestimated risk at the extremes of age. A sensitivity analysis demonstrated that an arbitrary change in the age category led to a different conclusion. Age modeled linearly adequately represented mortality risk but was suboptimal with repeat revascularization. Only the cubic spline demonstrated the nonlinear association between age and repeat revascularization.

CONCLUSION

Employing the continuous variable age as a case study, we have demonstrated that the use of flexible transformations, such as spline functions, can unearth clinically meaningful associations that would not have been possible otherwise. Future research should determine whether incorporation of these methods can improve decision making at a population level.

Comparison of the ATRIA, CHADS2, and CHA2DS2-VASc stroke risk scores in predicting ischaemic stroke in a large Swedish cohort of patients with atrial fibrillation

AIMS

Better stroke risk prediction is needed to optimize the anticoagulation decision in atrial fibrillation (AF). The ATRIA stroke risk score (ATRIA) was developed and validated in two large California community AF cohorts. We compared the performance of the ATRIA, CHADS₂, and CHA₂DS₂-VASc scores in a national Swedish AF (SAF) cohort.

METHODS AND RESULTS

We examined all Swedish patients hospitalized, or visiting a hospital-based outpatient clinic, with a diagnosis of AF from July 2005 through December 2010. Variables were determined from comprehensive national databases. Risk scores were assessed via C-index (C) and net reclassification improvement (NRI). The cohort included 152 153 AF patients not receiving warfarin. Overall, 11 053 acute ischaemic strokes were observed with mean rate 3.2%/year, higher than the 2%/year in the California cohorts. Using entire point scores, ATRIA had a good C of 0.708 (0.704-0.713), significantly better than CHADS₂ 0.690 (0.685-0.695) or CHA₂DS₂-VASc 0.694 (0.690-0.700). Using published cut-points for low/moderate/high risk, C deteriorated but ATRIA remained superior. Net reclassification improvement favoured ATRIA 0.16 (0.14-0.17) vs. CHADS₂ and 0.21 (0.20-0.23) vs. CHA₂DS₂-VASc. Net reclassification improvement decreased when cut-points were altered to better fit the cohort's stroke rates.

CONCLUSION

In this SAF cohort, the ATRIA score predicted ischaemic stroke risk better than CHADS₂ or CHA₂DS₂-VASc. However, relative performance of the categorical scores varied by population stroke rates. Score cut-points may need to be optimized to better fit local population stroke rates.

Incidence and timing of potentially high-risk arrhythmias detected through long term continuous ambulatory electrocardiographic monitoring

Background

Ambulatory electrocardiographic (ECG) monitoring is the standard to screen for high-risk arrhythmias. We evaluated the clinical utility of a novel, leadless electrode, single-patient-use ECG monitor that stores up to 14 days of a continuous recording to measure the burden and timing of potentially high-risk arrhythmias.

Methods

We examined data from 122,815 long term continuous ambulatory monitors (iRhythm ZIO® Service, San Francisco) prescribed from 2011 to 2013 and categorized potentially high-risk arrhythmias into two types: (1) ventricular arrhythmias including non-sustained and sustained ventricular tachycardia and (2) bradyarrhythmias including sinus pauses >3 s, atrial fibrillation pauses >5 s, and high-grade heart block (Mobitz Type II or third-degree heart block).

Results

Of 122,815 ZIO® recordings, median wear time was 9.9 (IQR 6.8–13.8) days and median analyzable time was 9.1 (IQR 6.4–13.1) days. There were 22,443 (18.3 %) with at least one episode of non-sustained ventricular tachycardia (NSVT), 238 (0.2 %) with sustained VT, 1766 (1.4 %) with a sinus pause >3 s (SP), 520 (0.4 %) with a pause during atrial fibrillation >5 s (AFP), and 1486 (1.2 %) with high-grade heart block (HGHB). Median time to first arrhythmia was 74 h (IQR 26–149 h) for NSVT, 22 h (IQR 5–73 h) for sustained VT, 22 h (IQR 7–64 h) for SP, 31 h (IQR 11–82 h) for AFP, and 40 h (SD 10–118 h) for HGHB.

Conclusions

A significant percentage of potentially high-risk arrhythmias are not identified within 48-h of ambulatory ECG monitoring. Longer-term continuous ambulatory ECG monitoring provides incremental detection of these potentially clinically relevant arrhythmic events.

Abstract TMP90: Limited Use of Oral Anticoagulant Therapy in Patients with Atrial Fibrillation After Ischemic Stroke

Introduction: Oral anticoagulants (OAC) prevent stroke in patients with atrial fibrillation (AF) yet many are not prescribed OAC. Exploring barriers to OAC among AF patients at high stroke risk might identify opportunities to intervene.

Hypothesis: Old age, fall risk, and comorbidity will be strong barriers to use of OAC even among survivors of acute ischemic stroke (IS).

Methods: Inpatient and 1-year follow-up of patients sustaining an acute IS within the ATRIA and ATRIA-CVRN community-based AF cohorts (1996-2009; n=46,806). MD chart reviewers recorded use of OAC (warfarin) at discharge (96% complete), reasons for non-use, and modified Rankin disability score at discharge. Logistic regression identified patient features associated with non-use of OAC. Follow-up recorded 1-year mortality and recurrent IS.

Results: Of 1,405 AF patients discharged alive after IS, 44% (619) were not prescribed OAC despite a median CHA2DS2-VASc score of 5. The most frequent (non-mutually exclusive) reasons for non-use of OAC included risk of falls (26.7%), poor prognosis (19.3%), bleeding history (17.1%), patient/family refusal (14.9%), older age (11.0%) and dementia (9.4%). Logistic regression identified older age (OR 9.0, 95% CI 5.0-16.0 for age ≥85 vs. <65 yrs) and increased disability on discharge (OR 12.6, 95% CI 5.8-27.2 for severe deficit vs. no deficit) as the strongest independent clinical features associated with non-use of OAC at discharge. One-year mortality for those not receiving OAC at discharge was 43%--far higher than risk of recurrent IS (7.7%).

Conclusions: Despite very high stroke risk, >40% of AF/IS patients were not discharged on OAC. The dominant reasons for non-use of OAC were fall risk, poor prognosis, bleeding history, patient refusal, older age, and dementia. The high 1-year mortality rate confirmed these patients’ high comorbidity burden. Effective mitigation of fall risk or the improved safety profiles of newer anticoagulants might increase use of OACs. However, despite the substantial stroke protection benefit from OACs, understandable obstacles to OAC remain for many older and complex AF patients.

Abstract WP303: Stability of High-Quality Warfarin Anticoagulation in a Community-Based Atrial Fibrillation Cohort: The ATRIA Study

Introduction: Warfarin reduces stroke risk in atrial fibrillation (AF), but increases bleed risk. Frequent testing with dose adjustment is needed to maintain INR levels in the therapeutic range of 2.0-3.0. Novel anticoagulants (NOACs) now challenge warfarin as stroke-preventive therapy for AF. They are available at fixed doses but costlier. Warfarin anticoagulation at a time in therapeutic range (TTR) ≥70% is similarly effective and safe as NOACs. It is unclear whether AF patients with TTR ≥70% will remain stably anticoagulated and avoid the need to switch to a NOAC. We assessed stability of warfarin anticoagulation in AF patients with an initial TTR ≥70% primarily managed by anticoagulation clinics.

Hypothesis: AF patients who achieve TTR ≥70% in the first 6 months of warfarin therapy will maintain high TTR subsequently.

Methods: Within the community-based ATRIA cohort of AF patients, we identified 2521 new warfarin users who continued warfarin therapy over 15 months. We excluded months 1-3 to achieve stable dose. For patients with TTR1 (months 4-9) ≥70% (TTR by Rosendaal method), we describe the distribution of TTR2 (months 10-15) and assess multivariable (logistic regression) correlates of persistent TTR ≥70%.

Results: Of 1074 patients with TTR1 ≥70%, 57% (95%CI: 53-61%) persisted with TTR2 ≥70% (Figure). Of multiple patient features, only initial TTR1 ≥90%, aOR [95% CI]: 1.43 [1.05,1.93]); and heart failure aOR: 0.78 [0.57, 1.06]) independently predicted TTR2 ≥70%.

Conclusions: Nearly 60% of AF patients with high quality initial 6-month TTR on warfarin will maintain TTR ≥70% over the next 6 months. A minority deteriorate to very poor TTR. Patient features do not strongly predict deterioration. Our analyses support watchful waiting for AF patients with initial high quality warfarin anticoagulation before switching to a NOAC.

Abrupt Decline in Kidney Function Before Initiating Hemodialysis and All-Cause Mortality: The Chronic Renal Insufficiency Cohort (CRIC) Study

BACKGROUND

It is not clear whether the pattern of kidney function decline in patients with chronic kidney disease (CKD) may relate to outcomes after reaching end-stage renal disease (ESRD). We hypothesize that an abrupt decline in kidney function prior to ESRD predicts early death after initiating maintenance hemodialysis therapy.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

The Chronic Renal Insufficiency Cohort (CRIC) Study enrolled men and women with mild to moderate CKD. For this study, we studied 661 individuals who developed chronic kidney failure that required hemodialysis therapy initiation.

PREDICTORS

The primary predictor was the presence of an abrupt decline in kidney function prior to ESRD. We incorporated annual estimated glomerular filtration rates (eGFRs) into a mixed-effects model to estimate patient-specific eGFRs at 3 months prior to initiation of hemodialysis therapy. Abrupt decline was defined as having an extrapolated eGFR≥30mL/min/1.73m(2) at that time point.

OUTCOMES

All-cause mortality within 1 year after initiating hemodialysis therapy.

MEASUREMENTS

Multivariable Cox proportional hazards.

RESULTS

Among 661 patients with CKD initiating hemodialysis therapy, 56 (8.5%) had an abrupt predialysis decline in kidney function and 69 died within 1 year after initiating hemodialysis therapy. After adjustment for demographics, cardiovascular disease, diabetes, and cancer, abrupt decline in kidney function was associated with a 3-fold higher risk for death within the first year of ESRD (adjusted HR, 3.09; 95% CI, 1.65-5.76).

LIMITATIONS

Relatively small number of outcomes; infrequent (yearly) eGFR determinations; lack of more granular clinical data.

CONCLUSIONS

Abrupt decline in kidney function prior to ESRD occurred in a significant minority of incident hemodialysis patients and predicted early death in ESRD.

Anemia and risk for cognitive decline in chronic kidney disease

Background

Anemia is common among patients with chronic kidney disease (CKD) but its health consequences are poorly defined. The aim of this study was to determine the relationship between anemia and cognitive decline in older adults with CKD.

Methods

We studied a subgroup of 762 adults age ≥55 years with CKD participating in the Chronic Renal Insufficiency Cohort (CRIC) study. Anemia was defined according to the World Health Organization criteria (hemoglobin <13 g/dL for men and <12 g/dL for women). Cognitive function was assessed annually with a battery of six tests. We used logistic regression to determine the association between anemia and baseline cognitive impairment on each test, defined as a cognitive score more than one standard deviation from the mean, and mixed effects models to determine the relation between anemia and change in cognitive function during follow-up after adjustment for demographic and clinical characteristics.

Results

Of 762 participants with mean estimated glomerular filtration rate of 42.7 ± 16.4 ml/min/1.73 m², 349 (46 %) had anemia. Anemia was not independently associated with baseline cognitive impairment on any test after adjustment for demographic and clinical characteristics. Over a median 2.9 (IQR 2.6–3.0) years of follow-up, there was no independent association between anemia and change in cognitive function on any of the six cognitive tests.

Conclusions

Among older adults with CKD, anemia was not independently associated with baseline cognitive function or decline.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-016-0226-6) contains supplementary material, which is available to authorized users.

Sinus Node Dysfunction Is Associated With Higher Symptom Burden and Increased Comorbid Illness: Results From the ORBIT-AF Registry

Background

Patients with sinus node dysfunction (SND) have increased risk of atrial tachyarrhythmias, including atrial fibrillation (AF). To date, treatment patterns and outcomes of patients with SND and AF have not been well described.

Hypothesis

Patients with SND and AF have higher risk of adverse cardiovascular outcomes.

Methods

Sinus node dysfunction was defined clinically, based on treating physician. Treatment patterns were described and logistic regression analysis performed to assess outcomes.

Results

Overall, 1710 (17.7%) out of 9631 patients had SND at enrollment. Patients with SND and AF had increased comorbid medical illnesses, more severe symptoms (European Heart Rhythm Association class IV: 17.5% vs 13.9%; P = 0.0007), and poorer quality of life (median 12‐month Atrial Fibrillation Effect on Quality of Life score: 79.6 vs 85.2; P = 0.0008). There were no differences in AF management strategy between patients with SND and those without (rate control, 69.7% vs 67.7%; rhythm control, 30.0% vs 32.0%; P = 0.11). After adjustment, patients with SND were more likely than those without SND to progress from paroxysmal AF at baseline to persistent or permanent AF at any follow‐up, or persistent AF at baseline to permanent AF at any follow‐up (odds ratio: 1.23, 95% confidence interval: 1.01‐1.49, P = 0.035). However, there was no association between SND and major risk‐adjusted outcomes.

Conclusions

Sinus node dysfunction is present in 1 of 6 patients with AF and is associated with increased comorbidities and higher symptom burden. However, SND is not associated with an increase in major risk‐adjusted outcomes.

Gastrointestinal symptoms, inflammation and hypoalbuminemia in chronic kidney disease patients: a cross-sectional study

Background

Few studies have focused on investigating hypoalbuminemia in patients during earlier stages of chronic kidney disease (CKD). In particular, little is known about the role of gastrointestinal (GI) symptoms. Our goal in this paper is to study how GI symptoms relate to serum albumin levels in CKD, especially in the context of and compared with inflammation.

Methods

We performed a cross-sectional study of 3599 patients with chronic kidney disease enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study. All subjects were asked to complete the Modification of Diet in Renal Disease (MDRD) study patient symptom form. Our main predictor is GI symptom score. Serum level of C-reactive protein (CRP) was measured as well. Main outcome measures are serum albumin levels and prevalence of hypoalbuminemia.

Results

Of the participants assessed, mean serum albumin was 3.95 ± 0.46 g/dL; 12.7 % had hypoalbuminemia. Patients with lower estimated glomerular filtration rate (eGFR) were likely to have more GI symptoms (apparent at an eGFR <45 ml/min/1.73 m²). Patients with worse GI symptoms had lower dietary protein intake. GI symptoms, like inflammation, were risk factors for lower serum albumin levels. However, adding GI symptom score or CRP into the multivariable regression analysis, did not attenuate the association between lower eGFR and lower albumin or hypoalbuminemia.

Conclusions

Increased prevalence of GI symptoms become apparent among CKD patients at relatively high eGFR levels (45 ml/min/1.73 m²), long before ESRD. Patients with more severe GI symptoms scores are more likely to have hypoalbuminemia. But our data do not support GI symptoms/decreased protein intake or inflammation as being the main determinants of serum albumin level in CKD patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0209-z) contains supplementary material, which is available to authorized users.

Metabolic Dyslipidemia and Risk of Coronary Heart Disease in 28,318 Adults With Diabetes Mellitus and Low-Density Lipoprotein Cholesterol <100 mg/dl

The risk of future coronary heart disease (CHD) in subjects with diabetes and "metabolic dyslipidemia" (high triglyceride [TGs] and low high-density cholesterol levels) remains a matter of concern. Little is known regarding the risk of CHD for this phenotype with low-density lipoprotein cholesterol (LDL-C) levels <100 mg/dl. We analyzed a diabetes cohort of 28,318 members (aged 30 to 90 years) of Kaiser Permanente Northern California during 2002 to 2011 (192,356 person-years [p-y] follow-up), with LDL-C levels <100 mg/dl and without known CHD. We compared the incidence and hazard ratios (HRs) for CHD events in groups using Cox models: normal high-density lipoprotein (HDL) and TG (reference; n = 7,278, 25.7%); normal HDL and high TG (≥ 150 mg/dl; n = 4,484,15.8%); low HDL (≤ 50 mg/dl for women and ≤ 40 mg/dl for men) and normal TG (n = 4,048, 14.3%); low HDL and high TG (metabolic dyslipidemia; n = 12,508, 44%). Patients with metabolic dyslipidemia had the highest age-adjusted CHD events/1,000 p-y (12.7/1,000 p-y and 19.0/1,000 p-y for women and men, respectively). After multivariate adjustment for age, gender, ethnicity, hypertension, smoking, statin use, duration of diabetes, and hemoglobin A1c, we observed an increased CHD risk in women (HR 1.35, 95% confidence interval 1.14 to 1.60) and men (HR 1.62, 95% confidence interval 1.43 to 1.83) with metabolic dyslipidemia compared to those with normal HDL and TG. Even in subjects with an LDL-C <100 mg/dl, presence of metabolic dyslipidemia in adults with diabetes is associated with an increased risk of CHD. In conclusion, effective CHD prevention strategies are needed for adults with diabetes and metabolic dyslipidemia.

Change in Measured GFR Versus eGFR and CKD Outcomes

Measured GFR (mGFR) has long been considered the gold standard measure of kidney function, but recent studies have shown that mGFR is not consistently superior to eGFR in explaining CKD-related comorbidities. The associations between longitudinal changes in mGFR versus eGFR and adverse outcomes have not been examined. We analyzed a subset of 942 participants with CKD in the Chronic Renal Insufficiency Cohort Study who had at least two mGFRs and two eGFRs determined concurrently by iothalamate and creatinine (eGFRcr) or cystatin C, respectively. We compared the associations between longitudinal changes in each measure of kidney function over 2 years and risks of ESRD, nonfatal cardiovascular events, and all-cause mortality using univariate Cox proportional hazards models. The associations for all outcomes except all-cause mortality associated most strongly with longitudinal decline in eGFRcr. Every 5-ml/min per 1.73 m(2) decline in eGFRcr over 2 years associated with 1.54 (95% confidence interval, 1.44 to 1.66; P<0.001) times higher risk of ESRD and 1.23 (95% confidence interval, 1.12 to 1.34; P<0.001) times higher risk for cardiovascular events. All-cause mortality did not associate with longitudinal decline in mGFR or eGFR. When analyzed by tertiles of renal function decline, mGFR did not outperform eGFRcr in the association with any outcome. In conclusion, compared with declines in eGFR, declines in mGFR over a 2-year period, analyzed either as a continuous variable or in tertiles, did not consistently show enhanced association with risk of ESRD, cardiovascular events, or death.

The Contemporary Safety and Effectiveness of Lower Extremity Bypass Surgery and Peripheral Endovascular Interventions in the Treatment of Symptomatic Peripheral Arterial Disease

BACKGROUND

Treatment for symptomatic peripheral artery disease includes lower extremity bypass surgery (LEB) and peripheral endovascular interventions (PVIs); however, limited comparative effectiveness data exist between the 2 therapies. We assessed the safety and effectiveness of LEB and PVI in patients with symptomatic claudication and critical limb ischemia.

METHODS AND RESULTS

In a community-based clinical registry at 2 large integrated healthcare delivery systems, we compared 883 patients undergoing PVI and 975 patients undergoing LEB between January 1, 2005 and December 31, 2011. Rates of target lesion revascularization were greater for PVI than for LEB in patients presenting with claudication (12.3±2.7% and 19.0±3.5% at 1 and 3 years versus 5.2±2.4% and 8.3±3.1%, log-rank P<0.001) and critical limb ischemia (19.1±4.8% and 31.6±6.3% at 1 and 3 years versus 10.8±2.5% and 16.0±3.2%, log-rank P<0.001). However, in comparison with PVI, LEB was associated with increased rates of complications up to 30 days following the procedure (37.1% versus 11.9%, P<0.001). There were no differences in amputation rates between the 2 groups. Findings remained consistent in sensitivity analyses by using propensity methods to account for treatment selection.

CONCLUSIONS

In patients with symptomatic peripheral artery disease, in comparison with LEB, PVI was associated with fewer 30-day procedural complications, higher revascularization rates at 1 and 3 years, and no difference in subsequent amputations.

Assessment of algorithms to identify patients with thrombophilia following venous thromboembolism

INTRODUCTION

Routine testing for thrombophilia following venous thromboembolism (VTE) is controversial. The use of large datasets to study the clinical impact of thrombophilia testing on patterns of care and patient outcomes may enable more efficient analysis of this practice in a wide range of settings. We set out to examine how accurately algorithms using International Classification of Diseases 9th Revision (ICD-9) codes and/or pharmacy data reflect laboratory-confirmed thrombophilia diagnoses.

MATERIALS AND METHODS

A random sample of adult Kaiser Permanente Colorado patients diagnosed with unprovoked VTE between 1/2004 and 12/2010 underwent medical record abstraction of thrombophilia test results. Algorithms using "ICD-9" (positive if a thrombophilia ICD-9 code was present), "Extended anticoagulation (AC)" (positive if AC therapy duration was >6 months), and "ICD-9 & Extended AC" (positive for both) criteria to identify possible thrombophilia cases were tested. Using positive thrombophilia laboratory results as the gold standard, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value of each algorithm were calculated, along with 95% confidence intervals (CIs).

RESULTS

In our cohort of 636 patients, sensitivities were low (<50%) for each algorithm. "ICD-9" yielded the highest PPV (41.5%, 95% CI 26.3-57.9%) and a high specificity (95.9%, 95% CI 94.0-97.4%). "Extended AC" had the highest sensitivity but lowest specificity, and "ICD-9 & Extended AC" had the highest specificity but lowest sensitivity.

CONCLUSIONS

ICD-9 codes for thrombophilia are highly specific for laboratory-confirmed cases, but all algorithms had low sensitivities. Further development of methods to identify thrombophilia patients in large datasets is warranted.

Comparative Effectiveness of Statin Therapy in Chronic Kidney Disease and Acute Myocardial Infarction: A Retrospective Cohort Study

BACKGROUND

Whether there is a kidney function threshold to statin effectiveness in patients with acute myocardial infarction is poorly understood. Our study sought to help fill this gap in clinical knowledge.

METHODS

We undertook a new-user cohort study of the effectiveness of statin therapy by level of estimated glomerular filtration rate (eGFR) in adults who were hospitalized for myocardial infarction between 2000 and 2008. Data came from the Cardiovascular Research Network. The primary clinical outcomes were 1-year all-cause mortality and cardiovascular hospitalizations, with adverse outcomes of myopathy and development of diabetes mellitus. We calculated incidence rates, the number needed to treat, and used Cox proportional hazards regression with propensity score matching and adjustment to control for confounding, with testing for variation of effect by level of kidney function.

RESULTS

Compared with statin non-initiators (n = 5583), statin initiators (n = 5597) had a lower propensity score-adjusted risk for death (hazard ratio 0.79; 95% confidence interval [CI], 0.71-0.88) and cardiovascular hospitalizations (hazard ratio 0.90; 95% CI, 0.82-1.00). We found little evidence of variation in effect by level of eGFR (P = .86 for death; P = .77 for cardiovascular hospitalization). Adverse outcomes were similar for statin initiators and statin non-initiators. The number needed to treat to prevent 1 additional death over 1 year of follow-up ranged from 15 (95% CI, 11-28) for eGFR <30 mL/min/1.73 m(2) requiring statin treatment over 2 years to prevent 1 additional death, to 67 (95% CI, 49-118) for patients with eGFR >90 mL/min/1.73 m(2).

CONCLUSIONS

Our findings suggest that there is potential for important public health gains by increasing the routine use of statin therapy for patients with lower levels of kidney function.

Anticoagulation in atrial fibrillation: impact of mental illness

OBJECTIVES

To characterize warfarin eligibility and receipt among Veterans Health Administration (VHA) patients with and without mental health conditions (MHCs).

STUDY DESIGN

Retrospective cohort study.

METHODS

This observational study identified VHA atrial fibrillation (AF) patients with and without MHCs in 2004. We examined unadjusted MHC-related differences in warfarin eligibility and warfarin receipt among warfarin-eligible patients, using logistic regression for any MHC and for specific MHCs (adjusting for sociodemographic and clinical characteristics).

RESULTS

Of 125,670 patients with AF, most (96.8%) were warfarin-eligible based on a CHADS2 stroke risk score. High stroke risk and contraindications to anticoagulation were both more common in patients with MHC. Warfarin-eligible patients with MHC were less likely to receive warfarin than those without MHC (adjusted odds ratio [AOR], 0.90; 95% CI, 0.87-0.94). The association between MHC and warfarin receipt among warfarin-eligible patients varied by specific MHC. Patients with anxiety disorders (AOR, 0.86; 95% CI, 0.80-0.93), psychotic disorders (AOR, 0.77; 95% CI, 0.65-0.90), and alcohol use disorders (AOR 0.62, 95% CI 0.54-0.72) were less likely to receive warfarin than patients without these conditions, whereas patients with depressive disorders and posttraumatic stress disorder were no less likely to receive warfarin than patients without these conditions.

CONCLUSIONS

Compared with patients with AF without MHCs, those with MHCs are less likely to be eligible for warfarin receipt and, among those eligible, are less likely to receive such treatment. Although patients with AF with MHC need careful assessment of bleeding risk, this finding suggests potential missed opportunities for more intensive therapy among some individuals with MHCs.