Chlorthalidone for Hypertension in Advanced Chronic Kidney Disease.

BACKGROUND: Little evidence has been available to support the use of thiazide diuretics to treat hypertension in patients with advanced chronic kidney disease. METHODS: We randomly assigned patients with stage 4 chronic kidney disease and poorly controlled hypertension, as confirmed by 24-hour ambulatory blood-pressure monitoring, in a 1:1 ratio to receive chlorthalidone at an initial dose of 12.5 mg per day, with increases every 4 weeks if needed to a maximum dose of 50 mg per day, or placebo; randomization was stratified according to previous use of loop diuretics. The primary outcome was the change in 24-hour ambulatory systolic blood pressure from baseline to 12 weeks. Secondary outcomes were the change from baseline to 12 weeks in the urinary albumin-to-creatinine ratio, N-terminal pro-B-type natriuretic peptide level, plasma renin and aldosterone levels, and total body volume. Safety was also assessed. RESULTS: A total of 160 patients underwent randomization, of whom 121 (76%) had diabetes mellitus and 96 (60%) were receiving loop diuretics. At baseline, the mean (±SD) estimated glomerular filtration rate was 23.2±4.2 ml per minute per 1.73 m2 of body-surface area and the mean number of antihypertensive medications prescribed was 3.4±1.4. At randomization, the mean 24-hour ambulatory systolic blood pressure was 142.6±8.1 mm Hg in the chlorthalidone group and 140.1±8.1 mm Hg in the placebo group and the mean 24-hour ambulatory diastolic blood pressure was 74.6±10.1 mm Hg and 72.8±9.3 mm Hg, respectively. The adjusted change in 24-hour systolic blood pressure from baseline to 12 weeks was -11.0 mm Hg (95% confidence interval [CI], -13.9 to -8.1) in the chlorthalidone group and -0.5 mm Hg (95% CI, -3.5 to 2.5) in the placebo group. The between-group difference was -10.5 mm Hg (95% CI, -14.6 to -6.4) (P<0.001). The percent change in the urinary albumin-to-creatinine ratio from baseline to 12 weeks was lower in the chlorthalidone group than in the placebo group by 50 percentage points (95% CI, 37 to 60). Hypokalemia, reversible increases in serum creatinine level, hyperglycemia, dizziness, and hyperuricemia occurred more frequently in the chlorthalidone group than in the placebo group. CONCLUSIONS: Among patients with advanced chronic kidney disease and poorly controlled hypertension, chlorthalidone therapy improved blood-pressure control at 12 weeks as compared with placebo. (Funded by the National Heart, Lung, and Blood Institute and the Indiana Institute of Medical Research; CLICK ClinicalTrials.gov number, NCT02841280.).

Myocardial strain is associated with adverse cardiac events in patients treated with chimeric antigen receptor (CAR) T-cell therapy.

BACKGROUND: Cardiovascular events, including heart failure and arrhythmias, following chimeric antigen receptor (CAR) T-cell therapy are increasingly recognized. Although global longitudinal strain (GLS) has demonstrated prognostic utility for other cancer therapy-related cardiac dysfunction, less is known regarding the association of GLS with adverse cardiac events following CAR T-cell therapy. OBJECTIVES: To determine the association of baseline GLS with adverse cardiovascular events in adults receiving CAR-T cell therapy. METHODS: Patients who had an echocardiogram within 6 months prior to receiving CAR T-cell therapy were retrospectively identified. Clinical data and cardiac events were collected via chart review. Echocardiograms were analyzed offline for GLS, left ventricular ejection fraction, and Doppler parameters. Multivariable logistic regression was used to determine the association between adverse cardiovascular events and echocardiographic parameters. RESULTS: Among 75 CAR T-cell therapy patients (mean age 63.9, 34.7% female), nine patients (12%) experienced cardiac events (CEs) including cardiovascular death, new/worsening heart failure, and new/worsening arrhythmia within 1 year of treatment. In univariable models, higher baseline GLS (OR 0.78 [0.63, 0.96], p = .021) was associated with a lower risk of CE and higher baseline mitral E/e' (OR 1.40 [1.08, 1.81], p = .012) was associated with a higher risk of CE. After adjusting for age and LDH, higher baseline GLS (OR 0.65 [0.48-0.88], p = <.01) was associated with a lower risk of CE and higher baseline mitral E/e' (OR 1.56 [1.06, 2.29], p = .024) was associated with a higher risk of CE. CONCLUSION: Lower GLS and higher mitral E/e' on a baseline echocardiogram were associated with higher risk for CEs in patients receiving CAR T-cell therapy.

Atherosclerotic Cardiovascular Disease or Heart Failure: First Cardiovascular Event in Adults With Prediabetes and Diabetes.

BACKGROUND: Individuals with prediabetes and diabetes are at increased risk of atherosclerotic cardiovascular disease (ASCVD) and heart failure (HF). Whether ASCVD or HF is more likely to occur first in these populations within different race-sex groups is unknown. OBJECTIVE: To determine the competing risk for the first cardiovascular event by subtype in Black and white men and women with prediabetes and diabetes. METHODS: Individual-level data from adults without ASCVD or HF were pooled from 6 population-based cohorts. We estimated the competing cumulative incidences of ASCVD, HF and noncardiovascular death as the first event in middle-aged (40-59 years) and older (60-79 years) adults, stratified by race and sex, with normal fasting plasma glucose (FPG < 100 mg/dL), prediabetes (FPG 100-125 mg/dL) and diabetes (FPG ≥ 126 mg/dL or on antihyperglycemic agents) at baseline. Within each race-sex group, we estimated risk the adjusted hazard ratio of ASCVD, HF and noncardiovascular death in adults with prediabetes and diabetes relative to adults with normoglycemia after adjusting for cardiovascular risk factors. RESULTS: In 40,117 participants with 638,910 person-years of follow-up, 5781 cases of incident ASCVD and 3179 cases of incident HF occurred. In middle-aged adults with diabetes, competing cumulative incidence of ASCVD as a first event was higher than HF in white men (35.4% vs 11.6%), Black men (31.6% vs 15.1%) and white women (24.3% vs 17.2%) but not in Black women (26.4% vs 28.4%). Within each group, the adjusted hazard ratio of ASCVD and HF was significantly higher in adults with diabetes than in adults with normal FPG levels. Findings were largely similar in middle-aged adults with prediabetes and older adults with prediabetes or diabetes. CONCLUSIONS: Black women with diabetes are more likely to develop HF as their first CVD event, whereas individuals with diabetes from other race-sex groups are more likely to present first with ASCVD. These results can inform the tailoring of primary prevention therapies for either HF- or ASCVD-specific pathways based on individual-level risk.

Association of fasting glucose with lifetime risk of incident heart failure: the Lifetime Risk Pooling Project.

BACKGROUND: Given the rising prevalence of dysglycemia and disparities in heart failure (HF) burden, we determined race- and sex-specific lifetime risk of HF across the spectrum of fasting plasma glucose (FPG). METHODS: Individual-level data from adults without baseline HF was pooled from 6 population-based cohorts. Modified Kaplan-Meier analysis, Cox models adjusted for the competing risk of death, and Irwin's restricted mean were used to estimate the lifetime risk, adjusted hazard ratio (aHR), and years lived free from HF in middle-aged (40-59 years) and older (60-79 years) adults with FPG < 100 mg/dL, prediabetes (FPG 100-125 mg/dL) and diabetes (FPG ≥ 126 mg/dL or on antihyperglycemic agents) across race-sex groups. RESULTS: In 40,117 participants with 638,910 person-years of follow-up, 4846 cases of incident HF occurred. The lifetime risk of HF was significantly higher among middle-aged White adults and Black women with prediabetes (range: 6.1% [95% CI 4.8%, 7.4%] to 10.8% [95% CI 8.3%, 13.4%]) compared with normoglycemic adults (range: 3.5% [95% CI 3.0%, 4.1%] to 6.5% [95% CI 4.9%, 8.1%]). Middle-aged Black women with diabetes had the highest lifetime risk (32.4% [95% CI 26.0%, 38.7%]) and aHR (4.0 [95% CI 3.0, 5.4]) for HF across race-sex groups. Middle-aged adults with prediabetes and diabetes lived on average 0.9-1.6 and 4.1-6.0 fewer years free from HF, respectively. Findings were similar in older adults except older Black women with prediabetes did not have a higher lifetime risk of HF. CONCLUSIONS: Prediabetes was associated with higher lifetime risk of HF in middle-aged White adults and Black women, with the association attenuating in older Black women. Black women with diabetes had the highest lifetime risk of HF compared with other race-sex groups.

Immune Dysregulation in Myocardial Fibrosis, Steatosis, and Heart Failure: Current Insights from HIV and the General Population.

PURPOSE OF REVIEW: HIV is an independent risk factor for heart failure (HF). Cardiac imaging studies in people with HIV (PWH) have identified myocardial pathologies, namely fibrosis and steatosis, that likely contribute to the higher risk of HF. In this review, we survey existing epidemiological, clinical, and mechanistic literature to identify potential pathways that may contribute to the burden of myocardial fibrosis and steatosis among PWH. RECENT FINDINGS: Multiple cohort studies over the past 20 years have demonstrated a roughly 2-fold higher risk of incident HF in PWH, as well as a disproportionate burden of myocardial fibrosis and steatosis in PWH without HF. Both myocardial fibrosis and steatosis are known contributors to HF in adults without HIV. Pathways involving the NLRP3 inflammasome, TGF-ß1, and adipocyte dysfunction are known to play a crucial role in the development of myocardial fibrosis and steatosis. Upregulation of these pathways in HIV due to direct effects of viral proteins, persistent immune dysregulation, gut epithelial breakdown and dysbiosis, and toxicities from antiretroviral therapy may contribute to myocardial dysfunction in HIV. Understanding these pathways may lead to more precise diagnostic and therapeutic targets to curb HF in PWH. During the past three decades, observational and mechanistic studies have provided important insights into risk factors and pathways that may contribute to the increased HF risk in PWH. Future work is needed to characterize these pathways more precisely in mechanistic studies of PWH, with the goal of ultimately deriving valuable targets for prevention, early diagnosis, and treatment of HF in PWH.

Design and Baseline Characteristics of the Chlorthalidone in Chronic Kidney Disease (CLICK) Trial.

BACKGROUND: Hypertension often accompanies chronic kidney disease (CKD), and diuretics are widely prescribed to reduce blood pressure (BP). Chlorthalidone (CTD) is a thiazide-like diuretic and an effective antihypertensive drug, yet little data exist to support its use in treating hypertension in individuals with advanced CKD. METHODS: Chlorthalidone in Chronic Kidney Disease (CLICK) is a phase II, single-institution, multicenter, double-blind randomized control trial to test the hypothesis that CTD improves BP, through reduction of extracellular fluid volume, and results in target organ protection in patients with stage 4 CKD and poorly controlled hypertension. After a single-blind placebo run-in for 2 weeks and confirmation of hypertension by 24-h ambulatory blood pressure (ABP), patients are randomized to either placebo or CTD 12.5 mg once daily (QD) followed by dose escalation. Randomization is stratified by prior loop diuretic use, and the double-blind phase lasts 12 weeks. With a total of 160 patients, the study will have ≥80% power to detect a 6 mm Hg difference in systolic 24-h ABP between the 2 treatment groups. RESULTS: Between June 2016 and October 2019, 131 patients have been randomized. The baseline characteristics are as follows: average age 65.8 years, 79% men, 36% Black, 79% with diabetes, mean eGFR 23.2 mL/min/1.73 m2, median urine albumin/creatinine ratio 923 mg/g, average number of BP medications 3.4, 60% on loop diuretics, and 24-h ABP averaged 141.7/73.8 mm Hg. CONCLUSION: Among patients with stage 4 CKD and uncontrolled hypertension, CLICK should answer the question whether CTD is safe and effective.

The histone demethylase Jmjd3 sequentially associates with the transcription factors Tbx3 and Eomes to drive endoderm differentiation.

Stem cell differentiation depends on transcriptional activation driven by lineage-specific regulators as well as changes in chromatin organization. However, the coordination of these events is poorly understood. Here, we show that T-box proteins team up with chromatin modifying enzymes to drive the expression of the key lineage regulator, Eomes during endodermal differentiation of embryonic stem (ES) cells. The Eomes locus is maintained in a transcriptionally poised configuration in ES cells. During early differentiation steps, the ES cell factor Tbx3 associates with the histone demethylase Jmjd3 at the enhancer element of the Eomes locus to allow enhancer-promoter interactions. This spatial reorganization of the chromatin primes the cells to respond to Activin signalling, which promotes the binding of Jmjd3 and Eomes to its own bivalent promoter region to further stimulate Eomes expression in a positive feedback loop. In addition, Eomes activates a transcriptional network of core regulators of endodermal differentiation. Our results demonstrate that Jmjd3 sequentially associates with two T-box factors, Tbx3 and Eomes to drive stem cell differentiation towards the definitive endoderm lineage.

Setting the dry weight and its cardiovascular implications.

Volume overload is common and associated with adverse outcomes in the hemodialysis population including systemic hypertension, pulmonary hypertension, left ventricular hypertrophy, and mortality. Since the beginning of the era of maintenance dialysis, prescribing and maintaining a dry weight remains the standard of care for managing volume overload on hemodialysis. Reducing dry weight even by relatively small amounts has been shown to improve blood pressure and has been associated with reductions in left ventricular hypertrophy. Maintaining an adequately low dry weight requires attention to sodium intake and adequate time on dialysis, as well as a high index of suspicion for volume overload. Reducing dry weight can provoke decreased cardiac chamber filling and is associated with risks including intradialytic hypotension. The ideal method to minimize intradialytic morbidity is unknown, but more frequent dialysis should be considered. Experimental methods of assessing volume status may allow identification of patients most likely both to tolerate and to benefit from dry weight reduction, but further study is needed.

Masked Uncontrolled Hypertension in CKD.

Masked uncontrolled hypertension (MUCH) is diagnosed in patients treated for hypertension who are normotensive in the clinic but hypertensive outside. In this study of 333 veterans with CKD, we prospectively evaluated the prevalence of MUCH as determined by ambulatory BP monitoring using three definitions of hypertension (daytime hypertension ≥135/85 mmHg; either nighttime hypertension ≥120/70 mmHg or daytime hypertension; and 24-hour hypertension ≥130/80 mmHg) or by home BP monitoring (hypertension ≥135/85 mmHg). The prevalence of MUCH was 26.7% by daytime ambulatory BP, 32.8% by 24-hour ambulatory BP, 56.1% by daytime or night-time ambulatory BP, and 50.8% by home BP. To assess the reproducibility of the diagnosis, we repeated these measurements after 4 weeks. Agreement in MUCH diagnosis by ambulatory BP was 75-78% (κ coefficient for agreement, 0.44-0.51), depending on the definition used. In contrast, home BP showed an agreement of only 63% and a κ coefficient of 0.25. Prevalence of MUCH increased with increasing clinic systolic BP: 2% in the 90-110 mmHg group, 17% in the 110-119 mmHg group, 34% in the 120-129 mmHg group, and 66% in the 130-139 mmHg group. Clinic BP was a good determinant of MUCH (receiver operating characteristic area under the curve 0.82; 95% confidence interval 0.76-0.87). In diagnosing MUCH, home BP was not different from clinic BP. In conclusion, among people with CKD, MUCH is common and reproducible, and should be suspected when clinic BP is in the prehypertensive range. Confirmation of MUCH diagnosis should rely on ambulatory BP monitoring.

Visceral Congestion in Heart Failure: Right Ventricular Dysfunction, Splanchnic Hemodynamics, and the Intestinal Microenvironment.

PURPOSE OF REVIEW: Visceral venous congestion of the gut may play a key role in the pathogenesis of right-sided heart failure (HF) and cardiorenal syndromes. Here, we review the role of right ventricular (RV) dysfunction, visceral congestion, splanchnic hemodynamics, and the intestinal microenvironment in the setting of right-sided HF. We review recent literature on this topic, outline possible mechanisms of disease pathogenesis, and discuss potential therapeutics. RECENT FINDINGS: There are several mechanisms linking RV-gut interactions via visceral venous congestion which could result in (1) hypoxia and acidosis in enterocytes, which may lead to enhanced sodium-hydrogen exchanger 3 (NHE3) expression with increased sodium and fluid retention; (2) decreased luminal pH in the intestines, which could lead to alteration of the gut microbiome which could increase gut permeability and inflammation; (3) alteration of renal hemodynamics with triggering of the cardiorenal syndrome; and (4) altered phosphate metabolism resulting in increased pulmonary artery stiffening, thereby increasing RV afterload. A wide variety of therapeutic interventions that act on the RV, pulmonary vasculature, intestinal microenvironment, and the kidney could alter these pathways and should be tested in patients with right-sided HF. The RV-gut axis is an important aspect of HF pathogenesis that deserves more attention. Modulation of the pathways interconnecting the right heart, visceral congestion, and the intestinal microenvironment could be a novel avenue of intervention for right-sided HF.

Thiazides in advanced chronic kidney disease: time for a randomized controlled trial.

PURPOSE OF REVIEW: Chronic kidney disease is common, associated with increased cardiovascular risk, and frequently complicated by hypertension, requiring multiple agents for control. Thiazides are naturally attractive for use in this population; unfortunately, they are classically thought to be ineffective in advanced chronic kidney disease based on both theoretical considerations and the earliest studies of these agents. This report reviews the studies of thiazide use in chronic kidney disease since the 1970s, including five randomized controlled trials, all of which report at least some degree of efficacy. RECENT FINDINGS: Two recent studies add further evidence for the utility and efficacy of thiazides in chronic kidney disease. Of these two, one used gold standard ambulatory blood pressure monitoring in patients with poorly controlled hypertension and advanced chronic kidney disease and found chlorthalidone reduces blood pressure. The second is the largest study to date of thiazides in chronic kidney disease; adding a fixed low-dose chlorthalidone as the first diuretic to the antihypertensive regimen improved blood pressure. SUMMARY: These numerous small but positive studies reinforce the need for a randomized trial to demonstrate safety and efficacy of thiazides in advanced chronic kidney disease.

Adverse effects of conventional thrice-weekly hemodialysis: is it time to avoid 3-day interdialytic intervals?

BACKGROUND: Maintenance hemodialysis is typically scheduled thrice weekly due to simple logistic reasons; thus, the vast majority of hemodialysis patients receive renal replacement therapy for two shorter 2-day intervals and a longer 3-day interval. As compared to the 2-day interval, we review the ill effects of the longer 3-day interdialytic interval in this report. SUMMARY: Large-scale observational studies show that both cardiovascular-related hospital admissions and mortality occur more frequently on the day following the long interdialytic interval than on any other day of the week. Although the reasons for excess mortality are obscure, several pathophysiologic mechanisms may be involved, such as a greater magnitude of change during the long interdialytic interval in the following parameters: volume status, electrolyte and acid-base status, arterial wall and left ventricle mechanics. These data raise the need for re-examining the issue of timing and frequency of prescribed dialysis regimens in an attempt to improve patient outcomes. Although enhanced-frequency and/or extended-time dialysis schedules may mitigate the risks of the long interdialytic interval, the benefit of such dialytic modalities on survival is not yet proven. Key Message: This article summarizes currently available epidemiologic and pathophysiologic evidence on the adverse effects related to the long interdialytic interval of thrice-weekly hemodialysis and discusses the need to research further alternative dialysis practices that could mitigate these risks.

Thiazide Diuretics in Chronic Kidney Disease.

Widely prevalent in the general population, chronic kidney disease (CKD) is frequently complicated with hypertension. Control of hypertension in this high-risk population is a major modifiable cardiovascular and renal risk factor but often requires multiple medications. Although thiazides are an attractive agent, guidelines have previously recommended against thiazide use in stage 4 CKD. We review the updated guidelines on thiazide use in advanced CKD, the antihypertensive mechanism of thiazides, and the clinical studies of thiazides in CKD. Older uncontrolled studies have shown that metolazone reduces blood pressure in CKD, but more recently small randomized controlled trials of hydrochlorothiazide in CKD have shown significant improvement in mean arterial pressure of 15 mmHg. Two recent uncontrolled studies of chlorthalidone including one that used ambulatory blood pressure monitoring found significant improvements in blood pressure. These findings all suggest that thiazides may be efficacious even in advanced CKD; however, electrolyte abnormalities were common in the studies reviewed so close monitoring is necessary during use. Adequately powered randomized trials are now needed before the routine use of thiazide diuretics in advanced CKD can be recommended.

Chlorthalidone for poorly controlled hypertension in chronic kidney disease: an interventional pilot study.

To test the hypothesis that thiazide-type diuretics effectively lower blood pressure (BP) in moderate to advanced chronic kidney disease (CKD; estimated GFR 20-45 ml/min/ 1.73 m(2)), after confirming poorly controlled hypertension with 24-hour ambulatory BP monitoring, chlorthalidone was added to existing medications in a dose of 25 mg/day, and the dose doubled every 4 weeks if the BP remained elevated. The average age of the 14 subjects was 67.5 years, a median of 4 antihypertensive drugs were used and estimated GFR was 26.8 ± 8.8 ml/min/1.73 m(2). Twelve subjects completed the 12-week treatment phase, and the 24-hour BP, which was 143.1/75.1 mm Hg at baseline, was reduced by 10.5/ 3.1 mm Hg (p = 0.01/p = 0.17). Home BP prior to initiating chlorthalidone was 152.4/82.6 mm Hg and fell at 4, 8, and 12 weeks by 10.2/4.8, 13.4/6.0, and 9.4/3.7 mm Hg (all p < 0.05). Maximal reduction in body weight and total body volume (measured by air displacement plethysmography) was seen at 8 weeks, concurrent with the maximal elevation in serum creatinine concentration and plasma renin activity. Albuminuria was significantly reduced by 40-45%. Adverse events were seen following chlorthalidone therapy in 7 subjects who experienced 18 events as follows: hypokalemia (n = 4), hyperuricemia (4), hyponatremia (3), transient creatinine changes (3), dizziness (2), hyperglycemia (1), and constipation (1). One subject had ischemic stroke during the study. In conclusion, among people with moderate to advanced CKD with poorly controlled hypertension, chlorthalidone may significantly reduce BP via volume contraction; a randomized trial is needed to define the risks and benefits. Adverse effects may occur within a few weeks and should be carefully monitored.

Hypertension in hemodialysis patients treated with atenolol or lisinopril: a randomized controlled trial.

BACKGROUND: The purpose of this study was to determine among maintenance hemodialysis patients with echocardiographic left ventricular hypertrophy and hypertension whether in comparison with a ß-blocker-based antihypertensive therapy, an angiotensin converting enzyme-inhibitor-based antihypertensive therapy causes a greater regression of left ventricular hypertrophy. METHODS: Subjects were randomly assigned to either open-label lisinopril (n = 100) or atenolol (n = 100) each administered three times per week after dialysis. Monthly monitored home blood pressure (BP) was controlled to <140/90 mmHg with medications, dry weight adjustment and sodium restriction. The primary outcome was the change in left ventricular mass index (LVMI) from baseline to 12 months. RESULTS: At baseline, 44-h ambulatory BP was similar in the atenolol (151.5/87.1 mmHg) and lisinopril groups, and improved similarly over time in both groups. However, monthly measured home BP was consistently higher in the lisinopril group despite the need for both a greater number of antihypertensive agents and a greater reduction in dry weight. An independent data safety monitoring board recommended termination because of cardiovascular safety. Serious cardiovascular events in the atenolol group occurred in 16 subjects, who had 20 events, and in the lisinopril group in 28 subjects, who had 43 events {incidence rate ratio (IRR) 2.36 [95% confidence interval (95% CI) 1.36-4.23, P = 0.001]}. Combined serious adverse events of myocardial infarction, stroke and hospitalization for heart failure or cardiovascular death in the atenolol group occurred in 10 subjects, who had 11 events and in the lisinopril group in 17 subjects, who had 23 events (IRR 2.29, P = 0.021). Hospitalizations for heart failure were worse in the lisinopril group (IRR 3.13, P = 0.021). All-cause hospitalizations were higher in the lisinopril group [IRR 1.61 (95% CI 1.18-2.19, P = 0.002)]. LVMI improved with time; no difference between drugs was noted. CONCLUSIONS: Among maintenance dialysis patients with hypertension and left ventricular hypertrophy, atenolol-based antihypertensive therapy may be superior to lisinopril-based therapy in preventing cardiovascular morbidity and all-cause hospitalizations. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases; ClinicalTrials.gov number: NCT00582114).

Mechanisms of antihypertensive effect of chlorthalidone in advanced chronic kidney disease-a causal mediation analysis.

BACKGROUND: Chlorthalidone in chronic kidney disease (CLICK) randomized trial demonstrated a robust reduction in systolic blood pressure (BP) in stage 4 chronic kidney disease (CKD). Here we explore the mechanisms underlying the antihypertensive effect of chlorthalidone. METHODS: In this prespecified analysis, we analyzed the contributions of baseline levels of 24-hour urinary sodium and aldosterone and the changes from baseline to 4 weeks in the multiple mediators reflecting volume status in a causal mediation analysis framework. Baseline levels of these mediators served as covariates. No power calculationfor this analysis was performed. RESULTS: Of the 160 patients randomized, 140 (87.5%) were included in this analysis. Compared to placebo, chlorthalidone within 4 weeks reduced weight -1.5 % (95% CI -2.2 to -0.7) and volume -1.4 % (95% CI -2.2 to -0.6), stimulated plasma renin 40.5% (95% CI 25.4 to 57.4%) and serum aldosterone 40.2% (95% CI 11.7% to 76%), and reduced plasma NT-pro BNP levels -19.4% (95% CI -33.8% to -1.9%). Mediation analysis revealed the following results: for weight change, the total effect on systolic BP was -10.8 mmHg (95% CI -16 to -5.7), of which weight change (indirect effect) accounted for -0.9 mmHg (95% CI -4.2 to 2.5) and BP change independent of weight (direct effect) accounted for -10 mmHg (-15.7 to - 4.2). Thus, the percent mediation was 8.1% (95% CI -22.4 to 38.5). Baseline excretion of 24-hour sodium or aldosterone or any of the changes in the above mediators examined accounted for <2 mmHg BP drop and were not significant for any of the mediators. CONCLUSION: Chlorthalidone improved BP control among patients with advanced CKD independently of baseline urinary sodium, aldosterone, weight loss, or changes in the renin-angiotensin system or NT-pro BNP. (Funded by the National Heart Lung and Blood Institute; CLICK ClinicalTrials.gov number, NCT02841280).

Designing target trials using electronic health records: A case study of second-line disease-modifying anti-rheumatic drugs and cardiovascular disease outcomes in patients with rheumatoid arthritis.

BACKGROUND: Emulation of the "target trial" (TT), a hypothetical pragmatic randomized controlled trial (RCT), using observational data can be used to mitigate issues commonly encountered in comparative effectiveness research (CER) when randomized trials are not logistically, ethically, or financially feasible. However, cardiovascular (CV) health research has been slow to adopt TT emulation. Here, we demonstrate the design and analysis of a TT emulation using electronic health records to study the comparative effectiveness of the addition of a disease-modifying anti-rheumatic drug (DMARD) to a regimen of methotrexate on CV events among rheumatoid arthritis (RA) patients. METHODS: We used data from an electronic medical records-based cohort of RA patients from Northwestern Medicine to emulate the TT. Follow-up began 3 months after initial prescription of MTX (2000-2020) and included all available follow-up through June 30, 2020. Weighted pooled logistic regression was used to estimate differences in CVD risk and survival. Cloning was used to handle immortal time bias and weights to improve baseline and time-varying covariate imbalance. RESULTS: We identified 659 eligible people with RA with average follow-up of 46 months and 31 MACE events. The month 24 adjusted risk difference for MACE comparing initiation vs non-initiation of a DMARD was -1.47% (95% confidence interval [CI]: -4.74, 1.95%), and the marginal hazard ratio (HR) was 0.72 (95% CI: 0.71, 1.23). In analyses subject to immortal time bias, the HR was 0.62 (95% CI: 0.29-1.44). CONCLUSION: In this sample, we did not observe evidence of differences in risk of MACE, a finding that is compatible with previously published meta-analyses of RCTs. Thoughtful application of the TT framework provides opportunities to conduct CER in observational data. Benchmarking results of observational analyses to previously published RCTs can lend credibility to interpretation.