The association of ECG and echocardiographic abnormalities with sudden cardiac death in a dialysis patient cohort

Impact of Electrocardiographic Parameters on Sudden Death in Patients Receiving Maintenance Hemodialysis: Ten-Year Outcomes of the Q-Cohort Study

AIM

Sudden death is one of the most common causes of death among hemodialysis patients. Electrocardiography (ECG) is a noninvasive and inexpensive test that is regularly performed in hemodialysis clinics. However, the association between abnormal ECG findings and the risk of sudden death in hemodialysis patients is yet to be fully elucidated. Thus, the aim of this study was to determine the ECG parameters linked to sudden death in patients undergoing hemodialysis.

METHODS

The Q-Cohort Study is a multicenter, longitudinal, observational study of hemodialysis patients. In this study, 1,153 Japanese hemodialysis patients aged ≥ 18 years with ECG data recorded within 1 year of study enrollment were followed up for 10 years. Cox proportional hazards models were used to estimate the multivariate-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for the association between ECG parameters and sudden death.

RESULTS

During the median follow-up period of 9.0 years, 517 patients died, 76 of whom exhibited sudden death. After adjusting for confounding factors, higher heart rate, QT prolongation, and left ventricular hypertrophy as per the Sokolow-Lyon voltage criteria were found to be independently associated with an increased risk of sudden death. The adjusted HRs [95% CIs] for each abnormal ECG parameter were 2.02 [1.05-3.89], 2.10 [1.30-1.77], and 1.91 [1.18-3.09], respectively.

CONCLUSIONS

Higher heart rate, QT prolongation, and left ventricular hypertrophy on ECG have been determined to be associated with an increased risk of sudden death. Therefore, regular ECG recording could enable medical practitioners to identify hemodialysis patients who require intervention to prevent lethal arrhythmia.

The number of valvular insufficiency is a strong predictor of cardiovascular and all-cause mortality in hemodialysis patients

OBJECTIVES

To investigate the relationship between the number of valvular insufficiency (VI) and emergency hospitalization or mortality in maintenance hemodialysis (HD) patients.

METHODS

The maintenance HD patients with cardiac ultrasonography were included. According to the number of VI ≥ 2 or not, the patients were divided into two groups. The difference of emergency hospitalized for acute heart failure, arrhythmia, acute coronary syndrome (ACS) or stroke, cardiovascular mortality, and all-cause mortality between the two groups were compared.

RESULTS

Among 217 maintenance HD patients, 81.57% had VI. 121 (55.76%) patients had two or more VI, and 96 (44.24%) with one VI or not. The study subjects were followed up for a median of 47 (3-107) months. At the end of the follow up, 95 patients died (43.78%), of whom 47 (21.66%) patients died because of cardiovascular disease. Age (HR 1.033, 95% CI 1.007-1.061, P = 0.013), number of VI ≥ 2 (HR 2.035, 95% CI 1.083-3.821, P = 0.027) and albumin (HR 0.935, 95% CI 0.881-0.992, P = 0.027) were independent risk factors for cardiovascular mortality. The three parameters were also independent risk factors for all-cause mortality. The patients with number of VI ≥ 2 were more likely to be emergency hospitalized for acute heart failure (56 [46.28%] vs 11 [11.46%], P = 0.001). On the contrary, the number of VI was not associated with emergency hospitalized for arrhythmia, ACS or stroke. Survival analysis results showed that probability of survival was statistically different in the two groups (P < 0.05), no matter based on cardiovascular mortality or all-cause mortality. Based on age, number of VI ≥ 2 and albumin, nomogram models for 5-year cardiovascular and all-cause mortality were built.

CONCLUSIONS

In maintenance HD patients, the prevalence of VI is prominently high. The number of VI ≥ 2 is associated with emergency hospitalized for acute heart failure, cardiovascular and all-cause mortality. Combining age, number of VI ≥ 2, and albumin can predict cardiovascular and all-cause mortality.

Impact of pulmonary hypertension on arteriovenous fistula failure of hemodialysis patients: A 10 years follow-up cohort study

BACKGROUND

Pulmonary hypertension (PH) is common in patients with end-stage renal disease (ESRD). Arteriovenous fistulas (AVF) creation may involve in the pathogenesis of PH. The aim of this study was to explore the impact of PH after AVF creation on the AVF failure rate in maintenance hemodialysis (MHD) patients.

METHODS

From January 1, 2009, to January 1, 2019, we retrospectively collected data of 578 MHD patients in Guangdong Provincial People's Hospital Blood Purification Center, China. Patients were followed-up until AVF failure or death or May 25, 2020. According to the systolic pulmonary artery pressure (SPAP) within 1 year after the establishment of AVF, the MHD patients were divided into three groups: SPAP ⩽ 35 mmHg, 35 < SPAP < 45 mmHg, SPAP ⩾ 45 mmHg. The primary outcome was AVF failure defined as AVF cannot complete hemodialysis. The secondary outcomes were all-cause mortality.

RESULTS

A total of 578 patients were analyzed. The average age was 60.66 ± 15.34 years (58.1% men). Of these, 26.1% of patients were reported PH. The SPAP exhibited a left-skewed nonparametric distribution and the overall SPAP after the creation of AVF was 39.00 (29.00-52.00) mmHg. The median follow-up was 5.8 (5.5-6.3) years. Overall, 12.8% (74/578) patients were reported AVF failure events. There was no significant difference in AVF failure rate among three groups (p = 0.070). A total of 111 (19.2%) died during the follow-up period. Compared with the SPAP ⩽35 mmHg group, only the all-cause death rate significantly increased in MHD patients with PH (p < 0.001).

CONCLUSIONS

The secondary pulmonary hypertension after AVF creation did not increase the risk of AVF failure in MHD patients, but significantly increased the risk of mortality for this portion of the patients. Future larger sample sizes, multi-center, and prospective trials are needed to make sure which type of access will benefit on their survival for MHD patients with SPAP ⩾35 mmHg.

Deep Learning Using Electrocardiograms in Patients on Maintenance Dialysis

Cardiovascular morbidity and mortality occur with an extraordinarily high incidence in the hemodialysis-dependent end-stage kidney disease population. There is a clear need to improve identification of those individuals at the highest risk of cardiovascular complications in order to better target them for preventative therapies. Twelve-lead electrocardiograms are ubiquitous and use inexpensive technology that can be administered with minimal inconvenience to patients and at a minimal burden to care providers. The embedded waveforms encode significant information on the cardiovascular structure and function that might be unlocked and used to identify at-risk individuals with the use of artificial intelligence techniques like deep learning. In this review, we discuss the experience with deep learning-based analysis of electrocardiograms to identify cardiovascular abnormalities or risk and the potential to extend this to the setting of dialysis-dependent end-stage kidney disease.

The potential of electrocardiography for cardiac risk prediction in chronic and end-stage kidney disease

Cardiovascular mortality is very high in chronic and end-stage kidney disease (ESKD). However, risk stratification data are lacking. Sudden cardiac deaths are among the most common cardiovascular causes of death in these populations. As a result, many studies have assessed the prognostic potential of various electrocardiographic parameters in the renal population. Recent data from studies of implantable loop recordings in haemodialysis patients from five different countries have shed light on a pre-eminent bradyarrhythmic risk of mortality. Importantly, heart block addressed by permanent pacing system was detected in a proportion of patients during the prolonged recording periods. Standard electrocardiogram is inexpensive, non-invasive and easily accessible. Hence, risk prediction models using this simple investigation tool could easily translate into clinical practice. We believe that electrocardiographic assessment is currently under-valued in renal populations. For this review, we identified studies from the preceding 10 years that assessed the use of conventional and novel electrocardiographic biomarkers as risk predictors in chronic and ESKD. The review indicates that conventional electrocardiographic markers are not reliable for risk stratification in the renal populations. Novel parameters have shown promising results in smaller studies, but further validation in larger populations is required.

Chronic kidney disease and peripheral nerve function in the Health, Aging and Body Composition Study

BACKGROUND

Chronic kidney disease (CKD) is associated with poor mobility. Peripheral nerve function alterations play a significant role in low mobility. We tested the hypothesis that early CKD is associated with altered sensory, motor and autonomic nerve function.

METHODS

Participants in the Health, Aging and Body Composition cohort who had kidney function measures in Year 3 (1999-2000) and nerve function measurements at Year 4 (2000-01) were analyzed (n = 2290). Sensory (vibration threshold, monofilament insensitivity to light and standard touch), motor [compound motor action potentials (CMAPs), nerve conduction velocities (NCVs)] and autonomic (heart rate response and recovery after a 400-m walk test) nerve function as well as participant characteristics were compared across cystatin C- and creatinine-based estimated glomerular filtration rate categorized as ≤60 (CKD) or >60 mL/min/1.73 m2 (non-CKD). The association between CKD and nerve function was examined with logistic regression adjusted for covariates.

RESULTS

Participants with CKD (n = 476) were older (77 ± 3 versus 75 ± 3 years; P < 0.05) and had a higher prevalence of diabetes (20.6% versus 13.1%; P < 0.001). CKD was associated with higher odds for vibration detection threshold {odds ratio [OR] 1.7 [95% confidence interval (CI) 1.1-2.7]} and light touch insensitivity [OR 1.4 (95% CI 1.1-1.7)]. CMAPs and NCVs were not significantly different between CKD and non-CKD patients. In adjusted analyses, participants with CKD had higher odds of an abnormal heart rate response [OR 1.6 (95% CI 1.1-2.2)] and poor heart rate recovery [OR 1.5 (95% CI 1.1-2.0)].

CONCLUSIONS

CKD is associated with changes in sensory and autonomic nerve function, even after adjustment for demographics and comorbidities, including diabetes. Longitudinal studies in CKD are needed to determine the contribution of nerve impairments to clinically important outcomes.