Association of Abnormal Serum Potassium Levels with Arrhythmias and Cardiovascular Mortality: a Systematic Review and Meta-Analysis of Observational Studies

PURPOSE

To provide the first systematic review and meta-analysis of observational studies on the association of abnormal serum potassium and cardiovascular outcomes.

METHODS

Medline and ISI Web of Knowledge were systematically searched from inception until November 24, 2017. Data synthesis of relevant studies was performed using random effects model meta-analyses.

RESULTS

Meta-analyses included 310,825 participants from 24 studies. In the older general population, low serum potassium was associated with a 1.6-fold increased risk of supraventricular arrhythmias (risk ratio [95% confidence interval] 1.62 [1.02-2.55]). Contrarily, high serum potassium was associated with increased cardiovascular mortality (CVM) (1.38 [1.14-1.66]). In patients with acute myocardial infarction, the risk of ventricular arrhythmias was increased for high serum potassium (2.33 [1.60-3.38]). A U-shaped association was observed with a composite cardiovascular outcome in hypertensive patients (2.6-fold increased risk with hypokalemia and 1.7-fold increased risk with hyperkalemia), with CVM in dialysis patients (1.1-fold increased risk with hypokalemia and 1.4-fold increased risk with hyperkalemia) and with CVM in heart failure patients (albeit not statistically significant). Further, only hyperkalemia was associated with an increased risk of a composite cardiovascular outcome in both dialysis (1.12 [1.03-1.23]) and chronic kidney disease (1.34 [1.06-1.71]) patients.

CONCLUSIONS

Controlled clinical trials are needed to determine which populations may profit from more frequent potassium-monitoring and subsequent interventions, e.g., change or withdrawal of potassium-influencing drugs, in order to restore normal values and prevent cardiovascular outcomes.

REGISTRATION DETAILS

Registration in PROSPERO (Centre for Reviews and Dissemination University of York, York, UK): CRD42016048897 ( https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=48897 ).

The Symptoms Prevalence, Medical Interventions, and Health Care Service Needs for Patients With End-Stage Renal Disease in a Renal Palliative Care Program

A retrospective study was conducted to evaluate the symptoms prevalence and interventions initiated in the last 2 weeks of life, health care service utilization, and causes of death of patients with end-stage renal disease (ESRD under a renal palliative care (RPC) program. A total of 335 RPC patients were included, of which 226 patients died during the study period. The 5 most prevalent symptoms were dyspnea (63.7%), fatigue (51.8%), edema (48.2%), pain (44.2%), and anorexia (38.1%); and the 5 most prevalent interventions initiated were oxygen (69.5%), parenteral infusion (67.3%), antibiotics (53.5%), bladder catheterization (44.7%), and analgesic (39.8%) in the last 2 weeks of life. Each patient received 3.5 ± 4.4 outpatient clinic visit, 3.4 ± 10.3 home care visits, and 3.1 ± 2.7 hospital admissions. Besides ESRD (51.8%), the most common causes of death were cardiovascular events (18.6%) and infection (17.2%).

Sudden cardiac arrest and sudden cardiac death on dialysis: Epidemiology, evaluation, treatment, and prevention

Sudden cardiac death is the most common cause of death in dialysis patients and is usually preceded by sudden cardiac arrest due to ventricular tachycardia or ventricular fibrillation. A variety of risk factors have been identified that predispose the sudden cardiac arrest and sudden cardiac death in dialysis patients. Primary prevention of sudden cardiac arrest in dialysis patients may be accomplished by avoiding the use of low potassium dialysate. Pharmacotherapy with beta-blockers angiotensin converting enzyme inhibitors and angiotensin receptor blockers and use of implantable cardioverter defibrillators (ICDs) may also prevent sudden cardiac arrest and sudden cardiac death in high-risk dialysis patients. Secondary prevention of sudden cardiac death may be accomplished by similar pharmacotherapy and by the use of ICDs. Indications for ICD use in dialysis patients are similar to those for nondialysis patients; however, survival rates following ICD implantation in dialysis patients are substantially lower than in non-dialysis patients.

β-Blockers for prevention of sudden cardiac death in patients on hemodialysis: a propensity score analysis of the HEMO Study

BACKGROUND

Hemodialysis patients have an elevated risk of sudden cardiac death. Although the efficacy of β-blockers for the prevention of sudden cardiac death has been proven in the general population, little evidence exists in patients with kidney failure.

STUDY DESIGN

Post hoc analysis of the Hemodialysis (HEMO) Study.

SETTING & PARTICIPANTS

Participants enrolled in the HEMO Study from May 1995 to February 2001.

INTERVENTION

β-Blocker use ascertained through self-reported questionnaires and dialysis clinic charts.

OUTCOMES

Sudden cardiac death adjudicated by a committee as a secondary outcome of interest.

MEASUREMENTS

We used Cox proportional hazards regression models, competing risk survival analysis, propensity score matching, and covariate adjustment to study the association of β-blockers with sudden cardiac death.

RESULTS

1,747 patients were included in this study, and 521 were on β-blocker therapy at baseline. Mean age was 58 years, 57% were women, and 39% had ischemic heart disease (IHD) at baseline. Baseline β-blocker use was not associated with lower risk of sudden cardiac death in univariate (cause-specific HR, 0.89; 95% CI, 0.64-1.24), multivariable (cause-specific HR, 0.87; 95% CI, 0.62-1.22), or propensity-matched (cause-specific HR, 0.91; 95% CI, 0.55-1.50) analyses. There was a significant interaction between β-blocker use and sudden cardiac death (interaction P = 0.03) in patients with (cause-specific HR, 0.65; 95% CI, 0.42-1.01) and without IHD (cause-specific HR, 1.61; 95% CI, 0.92-2.80).

LIMITATIONS

Observational nature of the study.

CONCLUSIONS

In hemodialysis patients without preexisting IHD, β-blocker use was not associated with lower risk of sudden cardiac death. However, there was a trend toward benefit in those with IHD.