Primary prevention of atrial fibrillation with beta-blockers in patients with end-stage renal disease undergoing dialysis

Current Knowledge of Beta-Blockers in Chronic Hemodialysis Patients

Beta-blockers include a large spectrum of drugs with various specific characteristics, and a well-known cardioprotective efficacy. They are recommended in heart failure, hypertension and arrhythmia. Their use in chronic hemodialysis patients is still controversial, mainly because of the lack of specific randomized clinical trials. Large observational studies and two important clinical trials have reported almost unanimously their efficacy in chronic hemodialysis patients, which seems to be related to their levels of dialyzability and cardioselectivity. A recent meta-analysis suggested that high dialyzable beta-blockers are correlated to a reduced risk of all-cause mortality and cardiovascular complications compared with low dialyzable beta-blockers. Despite their benefits, beta-blockers may have adverse effects, such as intradialytic hypotension with low dialyzability beta-blockers or the risk of sub-therapeutic plasma concentration of high dialyzable ones during dialysis sessions. Both cases are linked to adverse cardiovascular events. A solution for both high and low dialyzable drugs could be their administration after dialysis sessions. Futhermore, the bulk of existing literature seems to favor cardioselective beta-blockers with moderate-to-high dialyzability as the ideal agents in dialysis patients, but further, larger studies are needed. This review aims to analyze beta-blockers' characteristics, indications and evidence-based role in chronic hemodialysis patients.

Effects of β-blockers therapy on the 28-day and 3-year survival rates of end-stage renal disease patients with cardiovascular disease: a retrospective cohort study

Background

β-blockers have been used in the treatment of end-stage renal disease (ESRD) patients and cardiovascular disease (CVD) patients, separately. However, the effects of β-blockers on ESRD patients with CVD have not been fully investigated. This study sought to investigate the effects of β-blockers therapy on the 28-day and 3-year survival rates of ESRD patients with pre-existing CVD who were admitted to the intensive care unit (ICU).

Methods

After excluding patients without CVD, receiving a kidney transplant, not admitted to the ICU, and with missing baseline data, this cohort study included 1081 ESRD participants with CVD from the Medical Information Mark for Intensive Care III database. Baseline characteristics, including demographic data and clinical data, were collected. The outcomes were 28-day and 3-year survival rates of the patients. At the 28-day of ICU hospitalization, patients had a mean inpatient hospital stay of 24.7 days. At 3-year, the patients had a median survival time of 489.2 days. Univariate and multivariate Cox regression analyses were used to evaluate the effects of β-blockers therapy on the 28-day and 3-year survival outcomes of ESRD patients with CVD.

Results

The 28-day and 3-year survival rates were 82.8% and 37.9%, respectively. The mean age of the all patients was 68 years, and 642 were male. After adjusting for age, race, hyperlipidemia, dialysis, simplified acute physiological score (SAPS) II, sequential organ failure assessment (SOFA) score, glucocorticoid, hemoglobin, diabetes, hypertension, the 28-day survival rate of the ESRD patients with CVD requiring intensive care who received β-blockers therapy was higher than that of the patients who did not receive the treatment. Similarly, after adjusting for age, race, hyperlipidemia, dialysis, SAPS II, SOFA score, glucocorticoid, hemoglobin, diabetes, hypertension, creatinine, the long-term survival rate of the patients who received β-blockers therapy was also higher than that of those who did not.

Conclusions

β-blockers therapy was associated with increased 28-day and 3-year survival rates in ESRD patients with CVD requiring intensive care. Our findings may provide a theoretical basis for the prognostic impact of β-blockers therapy among patients with ESRD and CVD who were admitted to the ICU.

Risk of ischemic stroke in patients with hypertrophic cardiomyopathy in the absence of atrial fibrillation - a nationwide cohort study

Ischemic stroke (IS) is a catastrophic complication of hypertrophic cardiomyopathy (HCM) with aging. We investigated the incidence of IS in HCM patients without atrial fibrillation (AF) and compared the relative risk of IS with matched general population with AF. This study identified 17,371 HCM patients without AF and utilized propensity-score-matching to identify one-to-one matched control of general population with AF receiving oral anti-coagulants (OACs). During a median follow-up of 7.3 years, 847 (4.9%) subjects experienced IS with the incidence of 0.589/100 person-years. The corresponding matched controls experienced 788 (4.5%) events with the incidence of 0.494/100 person-years. Compared with control, HCM patients had similar risk of IS (Hazard ratios [HRs] 0.965, 95% confidence interval [CI] 0.854-1.091). HCM patients with age above 65 years had a significantly increased risk of IS (age 65-74 years, HR 1.278, 95% CI 1.070-1.335; age ≥75 years, HR 1.757, 95% CI 1.435-2.152). Stratified by CHA₂DS₂-VASc score, HCM subjects with score 0, 1 and 2 had significantly increased risk of IS than control while those with score ≥2 had similar risk as control. Compared with general population with AF, HCM patients without AF had similar risk of IS, suggesting OACs might be necessary in HCM patient without AF.

The clinical effect of arrhythmia monitoring after myocardial infarction (BIO-GUARD|MI):study protocol for a randomized controlled trial

BACKGROUND

The increasing use of implantable cardiac monitors (ICMs) allows early documentation of asymptomatic cardiac arrhythmias that would previously have gone unnoticed. The addition of remote monitoring to cardiac devices means that physicians receive an early warning in cases of new-onset arrhythmias. While remote monitoring has been suggested to increase survival in heart failure patients with implantable defibrillators, trials using ICMs for continuous electrocardiographic monitoring of cardiac arrhythmias in the postmyocardial infarction setting have shown that patients who experienced cardiac arrhythmias such as atrial fibrillation, bradycardia, and ventricular tachyarrhythmia have an increased risk of major adverse cardiac events.

METHODS

The Biomonitoring in patients with preserved left ventricular function after diagnosed myocardial infarction (BIO-GUARD-MI) study is designed to investigate and clarify whether the incidence of major adverse cardiac events can be decreased by early detection and treatment of cardiac arrhythmias using an ICM in patients after myocardial infarction. In addition, the study will allow us to describe the interplay between baseline characteristics, arrhythmias, and clinical events to improve the treatment of this high-risk patient population. The study will enroll and randomize a cohort of high-risk postmyocardial infarction patients with CHA2DS2-VASc score ≥ 4 and left ventricular ejection fraction > 35% to an ICM or conventional treatment. Physicians are provided with suggestions on how to respond to ICM-documented arrhythmias. An estimated 1400 patients will be enrolled and followed until 372 primary endpoints have occurred. In this paper, we describe the literature and rationale behind the design and interventions towards new-onset arrhythmias, as well as future perspectives and limitations for the use of ICMs.

DISCUSSION

Remote monitoring may improve clinical outcome if it uncovers conditions with low symptom burden which cause or indicate an increased risk. A simple and easily implementable response to the information is important. Cardiac arrhythmias frequently start as asymptomatic, shorter lasting, and nightly events. The BIO-GUARD-MI trial represents the first attempt to simplify the response to the rather complex nature of heart arrhythmias.

TRIAL REGISTRATION

Clinical Trials, NCT02341534 . Registered on 19 January 2015.

Myocardial adipose deposition and the development of heart failure with preserved ejection fraction

AIMS

It has been proposed that an increase of myocardial adiposity is related to left ventricular (LV) diastolic dysfunction. The specific roles of myocardial steatosis including epicardial fat and intramyocardial fat for diastolic function are unknown in those patients suffering heart failure (HF) with reduced (HFrEF) or preserved ejection fraction (HFpEF). This study aims to determine the complex relationship between myocardial adiposity in patients with HFrEF or HFpEF.

METHODS AND RESULTS

Using cardiac magnetic resonance imaging (CMRI), myocardial steatosis was measured in 305 subjects (34 patients with HFrEF, 163 with HFpEF, and 108 non-HF controls). We also evaluated cardiac structure and diastolic and systolic function by echocardiography and CMRI. Patients with HFpEF had significantly more intramyocardial fat than HFrEF patients or non-HF controls [intramyocardial fat content (%), 1.56 (1.26, 1.89) vs. 0.75 (0.50, 0.87) and 1.0 (0.79, 1.15), P < 0.05]. Intramyocardial fat amount (%) was higher in HFpEF women than in men [1.91% (1.17%, 2.32%) vs. 1.22 (0.87%, 2.02%), P = 0.01]. When estimated by CMRI (left ventricular peak filling rate), echocardiographic E/e' level, or left atrial volume index, intramyocardial fat correlated with LV diastolic dysfunction parameters in HFpEF patients, and this was independent of age, co-morbidities, body mass index, gender, and myocardial fibrosis (standardized coefficient: β = -0.34, P = 0.03; β = 0.29, P = 0.025; and β = 0.25, P = 0.02, respectively).

CONCLUSIONS

Patients with HFpEF had significantly more intramyocardial fat than HFrEF patients or non-HF controls. Independent of risk factors or gender, intramyocardial fat correlated with LV diastolic dysfunction parameters in HFpEF patients.

Beta-blockers use from the general to the hemodialysis population

Beta-blockers have numerous indications in the general population and are strongly recommended in heart failure, post-myocardial infarction and arrhythmias. In hemodialysis patients, their use is based on weak evidence because of the lack of a sufficient number of randomized clinical trials. The strongest evidence is based on two trials. The first showed better survival with carvedilol in hemodialysis patients with four sessions per week and systolic heart failure. The second found reduced cardiovascular morbidity with atenolol compared to lisinopril in mostly black hypertensive hemodialysis patients. No clinical trials exist regarding myocardial infarction. Large retrospective studies have assessed the benefits of beta-blockers in hemodialysis. A large cohort of hemodialysis patients with new-onset heart failure showed better survival when treated with carvedilol, bisoprolol or metoprolol. Another recent one of 20,064 patients found out that metoprolol compared to carvedilol was associated with less all-cause mortality. There is still uncertainty also regarding the impact of dialysability of beta-blockers on patient's survival. On top of that, many observations suggested that beta-blockers were associated with a reduced rate of sudden cardiac death in hemodialysis patients but recent data show a link between bradycardia and sudden cardiac death questioning the benefit of beta-blockade in this population. Finally, what we know for sure so far is that beta-blockers should be avoided in patients with intradialytic hypotension associated with bradycardia.

Association of Proteinuria and Incident Atrial Fibrillation in Patients With Intact and Reduced Kidney Function

BACKGROUND

Early evidence suggests proteinuria is independently associated with incident atrial fibrillation (AF). We sought to investigate whether the association of proteinuria with incident AF is altered by kidney function.

METHODS AND RESULTS

Retrospective cohort study using administrative healthcare databases in Ontario, Canada (2002-2015). A total of 736 666 patients aged ≥40 years not receiving dialysis and with no previous history of AF were included. Proteinuria was defined using the urine albumin-to-creatinine ratio (ACR) and kidney function by the estimated glomerular filtration rate (eGFR). The primary outcome was time to AF. Cox proportional models were used to determine the hazard ratio for AF censored for death, dialysis, kidney transplant, or end of follow-up. Fine and Grey models were used to determine the subdistribution hazard ratio for AF, with death as a competing event. Median follow-up was 6 years and 44 809 patients developed AF. In adjusted models, ACR and eGFR were associated with AF (P<0.0001). The association of proteinuria with AF differed based on kidney function (ACR × eGFR interaction, P<0.0001). Overt proteinuria (ACR, 120 mg/mmol) was associated with greater AF risk in patients with intact (eGFR, 120) versus reduced (eGFR, 30) kidney function (adjusted hazard ratios, 4.5 [95% CI, 4.0-5.1] and 2.6 [95% CI, 2.4-2.8], respectively; referent ACR 0 and eGFR 120). Results were similar in competing risk analyses.

CONCLUSIONS

Proteinuria increases the risk of incident AF markedly in patients with intact kidney function compared with those with decreased kidney function. Screening and preventative strategies should consider proteinuria as an independent risk factor for AF.