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

Advance care planning for patients with end-stage kidney disease on dialysis: narrative review of the current evidence, and future considerations

Patients with end-stage kidney disease (ESKD) have a high symptom-burden and high rates of morbidity and mortality. Despite this, evidence has shown that this patient group does not have timely discussions to plan for deterioration and death, and at the end of life there are unmet palliative care needs. Advance care planning is a process that can help patients share their personal values and preferences for their future care and prepare for declining health. Earlier, more integrated and holistic advance care planning has the potential to improve access to care services, communication, and preparedness for future decision-making and changing circumstances. However, there are many barriers to successful implementation of advance care planning in this population. In this narrative review we discuss the current evidence for advance care planning in patients on dialysis, the data around the barriers to advance care planning implementation, and interventions that have been trialled. The review explores whether the concepts and approaches to advance care planning in this population need to be updated to encompass current and future care. It suggests that a shift from a problem-orientated approach to a goal-orientated approach may lead to better engagement, with more patient-centred and satisfying outcomes.

Clinical Associations between Serial Electrocardiography Measurements and Sudden Cardiac Death in Patients with End-Stage Renal Disease Undergoing Hemodialysis

The rate of sudden cardiac death (SCD) for hemodialysis (HD) patients is significantly higher than that observed in the general population and have the highest risk for arrhythmogenic death. In this multi-center study, patients starting hemodialysis in each hospital were enrolled; they underwent regular check-ups in an open-patient clinic. We examined serial electrocardiography (ECG) data in patients undergoing HD and determined their associations with the occurrence of SCD. Of 678 enrolled subjects who underwent serial ECG before and after hemodialysis, 291 died and 39 developed SCD. In all subjects, the QT peak-to-end (QTpe) interval at all leads and QRS duration were shortened after hemodialysis. The SCD group showed a significant change in the QTpe interval of the inferior, anterior, and lateral leads before and after hemodialysis compared with the survivor group (p < 0.001). In the pre-hemodialysis ECG, SCD patients had significantly longer QTpe intervals in all leads (p < 0.001) and a longer QRS duration (92.6 ± 14.0 vs. 100.6 ± 14.9 ms, p = 0.015) than survivors. In conclusion, patients with a longer QTpe interval before hemodialysis and large changes in ECG parameters after hemodialysis might be at a higher risk of SCD. Therefore, changes in the ECG before and after hemodialysis could help to predict SCD.

αKlotho attenuates cardiac hypertrophy and increases myocardial fibroblast growth factor 21 expression in uremic rats

In chronic kidney disease (CKD), evidence suggests that soluble αKlotho (sKlotho) has cardioprotective effects. Contrariwise, high circulating levels of fibroblast growth factor 23 (FGF23) are related to uremic cardiomyopathy development. Recently, it has been demonstrated that sKlotho can act as a soluble FGF23 co-receptor, allowing sKlotho to modulate FGF23 actions in the myocardium, leading to the activation of cardioprotective pathways. Fibroblast growth factor 21 (FGF21) is a cardiomyokine with sKlotho-like protective actions and has never been evaluated in uremic cardiomyopathy. Here, we aimed to evaluate whether recombinant αKlotho (rKlotho) replacement can attenuate cardiac remodeling in an established uremic cardiomyopathy, and to explore its impact on myocardial FGF21 expression. Forty-six male Wistar rats were divided into three groups: control, CKD-untreated, and CKD treated with rKlotho (CKD + KL). CKD was induced by 5/6 nephrectomy. From weeks 4–8, the control and CKD-untreated groups received vehicle, whereas the CKD + KL group received subcutaneous rKlotho replacement (0.01 mg/kg) every 48 h. Myocardial remodeling was evaluated by heart weight/tibia length (HW/TL) ratio, echocardiographic parameters, myocardial histomorphometry, and myocardial expression of β-myosin heavy chain (MHCβ), alpha smooth muscle actin (αSMA), transient receptor potential cation channel 6 (TRPC6), and FGF21. As expected, CKD animals had reduced levels of sKlotho and increased serum FGF23 levels. Compared to the control group, manifest myocardial remodeling was present in the CKD-untreated group, while it was attenuated in the CKD + KL group. Furthermore, cardiomyocyte diameter and interstitial fibrotic area were reduced in the CKD + KL group compared to the CKD-untreated group. Similarly, rKlotho replacement was associated with reduced myocardial expression of TRPC6, MHCβ, and αSMA and a higher expression of FGF21. rKlotho showed cardioprotective effects by attenuating myocardial remodeling and reducing TRPC6 expression. Interestingly, rKlotho replacement was also associated with increased myocardial FGF21 expression, suggesting that an interaction between the two cardioprotective pathways needs to be further explored.

Impact statement

This study aimed to evaluate whether rKlotho replacement can attenuate cardiac remodeling in a post-disease onset therapeutic reasoning and explore the impact on myocardial FGF21 expression. This study contributes significantly to the literature, as the therapeutic effects of rKlotho replacement and FGF21 myocardial expression have not been widely evaluated in a setting of uremic cardiomyopathy. For the first time, it has been demonstrated that subcutaneous rKlotho replacement may attenuate cardiac remodeling in established uremic cardiomyopathy and increase myocardial expression of FGF21, suggesting a correlation between αKlotho and myocardial FGF21 expression. The possibility of interaction between the αKlotho and FGF21 cardioprotective pathways needs to be further explored, but, if confirmed, would point to a therapeutic potential of FGF21 in uremic cardiomyopathy.

The assessment of P-wave dispersion and myocardial repolarization parameters in patients with chronic kidney disease

Objective: The risks of sudden death and cardiac arrhythmia are increased in patients with chronic kidney disease (CKD). Here, we aimed to evaluate the indicators of arrhythmias, such as p-wave dispersion (P-WD), QTc dispersion, Tp-e and Tp-e/QT ratio in patients with CKD stages 3–5 on no renal replacement therapy (RRT).

Material and methods: One-hundred and thirty three patients with CKD stages 3–5 and 32 healthy controls were enrolled into the study. No patients received RRT. QTc dispersion, P-WD and Tp-e interval were measured using electrocardiogram and Tp-e/QT ratio was also calculated.

Results: Mean age rates were found similar in patients and controls (60.8 ± 14.2 and 61 ± 12.9 y, p = .937, respectively). Compared patients with controls, P-WD (45.85 ± 12.42 vs. 21.17 ± 6.6 msec, p < .001), QTc-min (366.99 ± 42.31 vs. 387.15 ± 20.5 msec, p < .001), QTc dispersion (71.13 ± 27.95 vs. 41.25 ± 14.55 msec, p < .001), Tp-e maximum (81.04 ± 10.34 vs. 75.49 ± 10.9 msec, p < .001), Tp-e minimum (62.25 ± 7.58 vs. 54.8 ± 6.72 msec, p < .001) and Tp-e/QTc ratio (0.19 ± 0.02 vs. 0.18 ± 0.01, p = .001) were found to be different. QTc-max and Tp-e interval were found to be similar in both groups.

Conclusion: P-WD and QTc dispersion, Tp-e interval and Tp-e/QTc ratio were found to be increased in with CKD stages 3–5 on no RRT.

Uremic Cardiomyopathy: A New Piece in the Chronic Kidney Disease-Mineral and Bone Disorder Puzzle

Cardiovascular diseases are the main cause of death in chronic kidney disease (CKD) patients. In dialysis patients, sudden cardiac death accounts for 40% of all deaths. In these patients, sudden cardiac death is usually secondary to an underlying cardiomyopathy, which is clinically identified by the high prevalence of left ventricular hypertrophy and the resultant mechanical and electrical dysfunction. CKD-related cardiomyopathy has a multifactorial pathophysiology. Recent evidence has highlighted the central pathophysiological role of chronic kidney disease-mineral and bone disorder (CKD-MBD) with hyperphosphatemia and high fibroblast growth factor 23 (FGF23) levels in these patients. Further, since CKD is known to be an αKlotho deficiency state, experimental studies have demonstrated that the deleterious effects of FGF23 can be minimized by reestablishing adequate soluble Klotho levels. Herein, we present a review that addresses not only the development of the understanding of CKD-related cardiomyopathy pathophysiology, but also explores the recent data that identify the triad of hyperphosphatemia, high FGF23 levels and αKlotho deficiency as playing a central role on it. Taken together, the data suggest that the uremic cardiomyopathy can be considered a new piece in the CKD-DMO puzzle.

Reduction in depressive symptoms in primary prevention ICD scheduled patients - One year prospective study

OBJECTIVE

Implantable Cardioverter Defibrillators (ICDs), have previously been associated with the onset of depression and anxiety. The aim of this one-year prospective study was to evaluate the rate of new onset psychopathological symptoms after elective ICD implantation.

METHODS

A total of 158 consecutive outpatients who were scheduled for an elective ICD implantation were diagnosed and screened based on the Mini International Neuropsychiatric Interview (MINI). Depression and anxiety were evaluated using the Hamilton Rating Scales for Depression (HAM-D) and Anxiety (HAM-A). Patient's attitude toward the ICD device was evaluated using a Visual Analog Scale (VAS).

RESULTS

Patients' mean age was 64±12.4years; 134 (85%) were men, with the majority of patients performing the procedure for reasons of 'primary prevention'. According to the MINI diagnosis at baseline, three (2%) patients suffered from major depressive disorder and ten (6%) from dysthymia. Significant improvement in HAM-D mean scores was found between baseline, three months and one year after implantation (6.50±6.4; 4.10±5.3 and 2.7±4.6, respectively F(2100)=16.42; p<0.001). There was a significantly more positive attitude toward the device over time based on the VAS score [F(2122)=53.31, p<0.001].

CONCLUSIONS

ICD implantation significantly contributes to the reduction of depressive symptoms, while the overall mindset toward the ICD device was positive and improved during the one-year follow-up.

Prognostic Benefits of Carvedilol, Bisoprolol, and Metoprolol Controlled Release/Extended Release in Hemodialysis Patients with Heart Failure: A 10-Year Cohort

BACKGROUND

Heart failure is a highly prevalent cardiovascular complication among patients receiving long-term hemodialysis, but the benefits of carvedilol, bisoprolol, and metoprolol controlled release/extended release on the outcomes of these patients remain unclear. In this study, we address the use of these 3 β-blockers and their associations with mortality.

METHODS AND RESULTS

Long-term hemodialysis patients, aged ≥35 years, with new-onset heart failure and receiving various medications were identified through the use of 1999-2010 data from the Taiwan National Health Insurance Research Database. From the total of 4435 heart failure patients, we selected 1700 new users of the 3 β-blockers (study group) and 1700 nonusers (control group), by using matched cohorts according to their propensity scores, and then compared the 5-year all-cause mortality rates by using Cox proportional hazard regressions and time-dependent covariate adjustment. During 3944 person-years of follow-up, 666 (39.2%) deaths occurred within the study group, compared with 918 (54%) deaths during 2893 person-years of follow-up in the control group. The 5-year mortality rate for the study (control) group was 54.5% (70.3%); P<0.001. Adjusted hazard regression analyses revealed that the therapeutic effects of β-blockers remained significant for all-cause mortality (hazard ratio 0.80, 95% CI 0.72 to 0.90). Subgroup analyses revealed that patients in the study group receiving β-blockers plus renin-angiotensin system antagonists exhibited the lowest mortality rate, while the highest mortality rate was found among patients in the control group receiving neither β-blockers nor renin-angiotensin system antagonists.

CONCLUSIONS

This study demonstrates that the 3 β-blockers were associated with improved survival in long-term hemodialysis patients with heart failure.

Do implantable cardioverter defibrillators contribute to new depression or anxiety symptoms? A retrospective study

OBJECTIVE

In this retrospective cross-sectional study, we evaluated the existence of psychiatric symptoms which appeared after implantation of an implantable cardioverter defibrillator (ICD).

METHODS

Patients with ICDs were diagnosed using the Mini International Neuropsychiatric Interview (MINI) and were excluded if they had any psychiatric diagnosis prior to ICD implantation. Depression and anxiety were evaluated using the HAM-D and HAM-A rating scales and their attitude towards the ICD using a visual analog scale (VAS). Ninety five ICD patients with mean age of 66 years (±11.5) were recruited, 80 (84%) were men.

RESULTS

Four (4%) patients were diagnosed with new-onset MDD and one patient (1%) with anxiety. Twenty seven (28%) were found to have significant depressive symptoms (HAM-D >8), without MDD diagnosis; half of them attributing these symptoms to the device. Seven (8%) patients experienced phantom shocks and had relatively higher depressive scores (HAM-D 10.3 vs. 5.8; F = 3.696; p = 0.058). The MDD rates in our study were rather consistent with those reported for cardiac patients.

CONCLUSIONS

We suggest that ICD contributed little, if any, additional depressive or anxiety symptoms after implantation. We found that the overall attitude towards the device was positive and that shocks and phantom shocks were related to depressive symptoms.

[Cardiac arrest in dialysis patients: Risk factors, preventive measures and management in 2015]

Patients undergoing hemodialysis have a 10 to 20 times higher risk of sudden cardiac arrest (SCA) than the general population. Sudden cardiac death is a rare event (approximately 1 event per 10,000 sessions) but has a very high mortality rate. Epidemiological data comes almost exclusively from North American studies; there is a great lack of European data on the subject. Ventricular arrhythmia is the main mechanism of sudden cardiac deaths in dialysis patients. These patients develop increased sensitivity mainly due to a high prevalence of severe ischemic heart disease and left ventricular hypertrophy and to a frequent trigger event: electrolytic and plasma volume shifts during dialysis sessions. Unfortunately, accurate predictive markers of SCA do not exist, however some primary prevention trials using beta-blockers or angiotensin II receptor blockers are encouraging, while the use of implantable cardioverter defibrillators in the population of chronic dialysis patients remains controversial. Identification of patients at risk, minimizing trigger events such as electrolytic shifts and improving team skills in the diagnosis and initial resuscitation with the latest recommendations from 2010 seem necessary to reduce incidence and improve survival in this high risk population. Organization of European studies would also allow a more accurate view of this reality in our dialysis units.

Hydrogen-rich saline improves survival and neurological outcome after cardiac arrest and cardiopulmonary resuscitation in rats

BACKGROUND

Sudden cardiac arrest is a leading cause of death worldwide. Three-fourths of cardiac arrest patients die before hospital discharge or experience significant neurological damage. Hydrogen-rich saline, a portable, easily administered, and safe means of delivering hydrogen gas, can exert organ-protective effects through regulating oxidative stress, inflammation, and apoptosis. We designed this study to investigate whether hydrogen-rich saline treatment could improve survival and neurological outcome after cardiac arrest and cardiopulmonary resuscitation, and the mechanism responsible for this effect.

METHODS

Sprague-Dawley rats were subjected to 8 minutes of cardiac arrest by asphyxia. Different doses of hydrogen-rich saline or normal saline were administered IV at 1 minute before cardiopulmonary resuscitation, followed by injections at 6 and 12 hours after restoration of spontaneous circulation, respectively. We assessed survival, neurological outcome, oxidative stress, inflammation biomarkers, and apoptosis.

RESULTS

Hydrogen-rich saline treatment dose dependently improved survival and neurological function after cardiac arrest/resuscitation. Moreover, hydrogen-rich saline treatment dose dependently ameliorated brain injury after cardiac arrest/resuscitation, which was characterized by the increase of survival neurons in hippocampus CA1, reduction of brain edema in cortex and hippocampus, preservation of blood-brain barrier integrity, as well as the decrease of serum S100β and neuron-specific enolase. Furthermore, we found that the beneficial effects of hydrogen-rich saline treatment were associated with decreased levels of oxidative products (8-iso-prostaglandin F2α and malondialdehyde) and inflammatory cytokines (tumor necrosis factor-α, interleukin-1β, and high-mobility group box protein 1), as well as the increased activity of antioxidant enzymes (superoxide dismutase and catalase) in serum and brain tissues. In addition, hydrogen-rich saline treatment reduced caspase-3 activity in cortex and hippocampus after cardiac arrest/resuscitation.

CONCLUSIONS

Hydrogen-rich saline treatment improved survival and neurological outcome after cardiac arrest/resuscitation in rats, which was partially mediated by reducing oxidative stress, inflammation, and apoptosis.

Near-term prediction of sudden cardiac death in older hemodialysis patients using electronic health records

BACKGROUND AND OBJECTIVES

Sudden cardiac death is the most common cause of death among individuals undergoing hemodialysis. The epidemiology of sudden cardiac death has been well studied, and efforts are shifting to risk assessment. This study aimed to test whether assessment of acute changes during hemodialysis that are captured in electronic health records improved risk assessment.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data were collected from all hemodialysis sessions of patients 66 years and older receiving hemodialysis from a large national dialysis provider between 2004 and 2008. The primary outcome of interest was sudden cardiac death the day of or day after a dialysis session. This study used data from 2004 to 2006 as the training set and data from 2007 to 2008 as the validation set. The machine learning algorithm, Random Forests, was used to derive the prediction model.

RESULTS

In 22 million sessions, 898 people between 2004 and 2006 and 826 people between 2007 and 2008 died on the day of or day after a dialysis session that was serving as a training or test data session, respectively. A reasonably strong predictor was derived using just predialysis information (concordance statistic=0.782), which showed modest but significant improvement after inclusion of postdialysis information (concordance statistic=0.799, P<0.001). However, risk prediction decreased the farther out that it was forecasted (up to 1 year), and postdialytic information became less important.

CONCLUSION

Subtle changes in the experience of hemodialysis aid in the assessment of sudden cardiac death and are captured by modern electronic health records. The collected data are better for the assessment of near-term risk as opposed to longer-term risk.

How safe is renal replacement therapy? A national study of mortality and adverse events contributing to the death of renal replacement therapy recipients

BACKGROUND

Patients receiving treatment with renal replacement therapy (RRT) have high mortality, and ensuring patient safety in this population is difficult. We aimed to estimate the incidence and nature of medical adverse events contributing to the death of patients being treated with RRT.

METHODS

This population registry-based retrospective case review study included all patients being treated with RRT for established renal failure in Scotland and who died between 1 January 2008 and 30 June 2011. Deaths were reviewed by consultant nephrologists using a structured questionnaire to identify factors contributing to death occurring in both the inpatient and outpatient setting. Reviewers were able to use any information source deemed relevant, including paper and electronic clinical records, mortality and morbidity meetings and procurator fiscal (Scottish coroner) investigations. Deaths occurring in 2008 and 2009 where avoidable factors were identified that may have or did lead to death of a patient were subject to further review and root cause analysis, in order to identify recurrent themes.

RESULTS

Of 1551 deaths in the study period, 1357 were reviewed (87.5%). Cumulative RRT exposure in the cohort was 2.78 million person-days. RRT complications were the primary cause of death in 28 (2.1%). Health-care-associated infection had contributed to 9.6% of all deaths. In 3.5% of deaths, factors were identified which may have or did contribute to death. These were both organizational and human error related and were largely due to five main causes: management of hyperkalaemia, prescribing, out of hours care, infection and haemodialysis vascular access.

CONCLUSIONS

Adverse events contributing to death in RRT recipients mainly relate to the everyday management of common medical problems and not the technical aspects of RRT. Efforts to avoid harm in this population should address these ubiquitous causes of harm.

Standardising dialysate potassium does not increase patient risk

BACKGROUND

Rapid intradialytic potassium shifts during haemodialysis have been associated with increased mortality and morbidity. Standardising dialysate potassium to 2 mmol/l may decrease the potassium shift.

OBJECTIVE

To examine the effect of standardising dialysate potassium to 2 mmol/l for all chronic dialysis treatments.

DESIGN

Pre- and post-intervention comparison of monthly serum potassium.

PARTICIPANTS

Ninety-seven individuals, of whom 56 patients could be matched across both data collection periods.

METHODS

Serum potassium data were categorised based on a target range 3.5-6.0 mmol/l. Overall pre- and post-intervention mean scores were compared using a paired samples t-test. Data for patients routinely prescribed dialysate potassium 1 mmol/l pre-intervention (n = 6) underwent paired samples t-test to compare their mean serum potassium pre- and post-intervention.

RESULTS

There was no statistically significant change in serum potassium post-intervention. The majority of patients remained within the target range, including the subset of patients who had a history of high serum potassium during the pre-intervention period.

CONCLUSIONS

A standard potassium dialysate of 2 mmol/l may reduce intradialytic serum potassium shifts and may assist in standardising safer work practices.

The impact of hemodialysis on the dispersion of ventricular repolarization

BACKGROUND

Sudden cardiac death is prevalent in chronic hemodialysis (HD) patients while the dialysis process may have arrhythmogenic potential. We sought to examine the effect of HD on conventional electrocardiographic parameters as well as on novel indexes of repolarization, given that increased spatial dispersion of repolarization is related to ventricular arrhythmias.

METHODS

We recorded clinical, echocardiographic, and laboratory parameters as well as electrocardiographic indexes before and after a single HD session. Specifically, we calculated the QTc interval, the QRS duration, the T peak-to-end (Tpe) interval, and the Tpe/QT ratio.

RESULTS

The study population consisted of 66 chronic HD patients (mean age: 68.9 ± 11.8 years, 40 males). Heart rate, blood pressure, QRS duration, QTc interval, and QT dispersion did not change significantly after the HD session. However, the Tpe interval and the Tpe/QT ratio increased significantly (80 [65-90] ms vs 85 [77.5-100] ms; P = 0.04, and 0.21 [0.18-0.24] vs 0.25 [0.21-0.28]; P = 0.05, respectively). Correlation analysis and multiple regression analysis failed to show significant associations between the baseline parameters and the baseline values of Tpe and Tpe/QT or between the change of the laboratory parameters during HD and the corresponding change of the Tpe and the Tpe/QT values. No significant arrhythmias were observed during the HD sessions.

CONCLUSIONS

HD induces an increase in novel markers of spatial dispersion of ventricular repolarization. Whether the assessment of these indexes of heterogeneity of repolarization at baseline or their change during HD has a prognostic value with regard to future untoward events, remains to be elucidated.