Initiation of Dialysis Is Associated With Impaired Cardiovascular Functional Capacity

Background The transition to dialysis period carries a substantial increased cardiovascular risk in patients with chronic kidney disease. Despite this, alterations in cardiovascular functional capacity during this transition are largely unknown. The present study therefore sought to assess ventilatory exercise response measures in patients within 1 year of initiating dialysis. Methods and Results We conducted a cross‐sectional study of 241 patients with chronic kidney disease stage 5 from the CAPER (Cardiopulmonary Exercise Testing in Renal Failure) study and from the intradialytic low‐frequency electrical muscle stimulation pilot randomized controlled trial cohorts. Patients underwent cardiopulmonary exercise testing and echocardiography. Of the 241 patients (age, 48.9 [15.0] years; 154 [63.9%] men), 42 were predialytic (mean estimated glomerular filtration rate, 14 mL·min −1 ·1.73 m −2 ), 54 had a dialysis vintage ≤12 months, and 145 had a dialysis vintage >12 months. Dialysis vintage ≤12 months exhibited a significantly impaired cardiovascular functional capacity, as assessed by oxygen uptake at peak exercise (18.7 [5.8] mL·min −1 ·kg −1 ) compared with predialysis (22.7 [5.2] mL·min −1 ·kg −1 ; P <0.001). Dialysis vintage ≤12 months also exhibited reduced peak workload, impaired peak heart rate, reduced circulatory power, and increased left ventricular mass index ( P <0.05 for all) compared with predialysis. After excluding those with prior kidney transplant, dialysis vintage >12 months exhibited a lower oxygen uptake at peak exercise (17.0 [4.9] mL·min −1 ·kg −1 ) compared with dialysis vintage ≤12 months (18.9 [5.9] mL·min −1 ·kg −1 ; P =0.033). Conclusions Initiating dialysis is associated with a significant impairment in oxygen uptake at peak exercise and overall decrements in ventilatory and hemodynamic exercise responses that predispose patients to functional dependence. The magnitude of these changes is comparable to the differences between low‐risk New York Heart Association class I and higher‐risk New York Heart Association class II to IV heart failure

Short-term metal particulate exposures decrease cardiac acceleration and deceleration capacities in welders: a repeated-measures panel study

Objective: Acceleration (AC) and deceleration (DC) capacities measure heart rate variability during speeding up and slowing down of the heart, respectively. We investigated associations between AC and DC with occupational short-term metal PM2.5 exposures. Methods: A panel of 48 male welders had particulate matter less than 2.5 microns in diameter (PM2.5) exposure measurements over 4–6 h repeated over 5 sampling periods between January 2010 and June 2012. We simultaneously obtained continuous recordings of digital ECG using a Holter monitor. We analysed ECG data in the time domain to obtain hourly AC and DC. Linear mixed models were used to assess the associations between hourly PM2.5 exposure and each of hourly AC and DC, controlling for age, smoking status, active smoking, exposure to secondhand smoke, season/time of day when ECG reading was obtained and baseline AC or DC. We also ran lagged exposure response models for each successive hour up to 3 h after onset of exposure. Results: Mean (SD) shift PM2.5 exposure during welding was 0.47 (0.43) mg/m3. Significant exposure–response associations were found for AC and DC with increased PM2.5 exposure. In our adjusted models without any lag between exposure and response, a 1 mg/m3 increase of PM2.5 was associated with a decrease of 1.46 (95% CI 1.00 to 1.92) ms in AC and a decrease of 1.00 (95% CI 0.53 to 1.46) ms in DC. The effect of PM2.5 on AC and DC was maximal immediately postexposure and lasted 1 h following exposure. Conclusions: There are short-term effects of metal particulates on AC and DC

Three-Year Survival after Transcatheter Aortic Valve Replacement: Findings from the Marshfield Aortic Valve Experience (MAVE) Study

Background: Transcatheter aortic valve replacement (TAVR) is a rapidly evolving treatment for severe aortic stenosis. However, uncertainties exist for optimal valve selection as there are few long-term studies comparing patient survival by valve type.Objective: We hypothesized that self-expandable valves (SEV) would provide a survival advantage over balloon expandable valves (BEV), as SEV continue to expand and might better accommodate to the anatomy of the aortic valve over time.Methods: We examined outcomes according to valve type from a rural tertiary referral center between 2012 and 2017.Results: Out of 269 patients, 77 deaths (28.6%) occurred over the study period with 6 deaths by 1 month post-TAVR and 37 deaths by 1 year post-TAVR. The median observation time for survivors was 21.5 months. The probability of survival at 3 years was 60.7% and 61.9% for patients who underwent treatment with SEV and BEV, respectively. There was no statistically significant difference in overall patient survival with or without adjustment for factors such as age, sex, race, and aortic valve area. Additionally, in a secondary analysis restricted to those patients treated in later years (2015-2017) survival among patients with BEV appeared superior (HR=0.456, P=0.015).Conclusion: Patients who underwent TAVR at a rural medical center with SEV showed similar survival compared to those who received a BEV. Superior survival was observed among those who received BEV versus SEV between 2015 and 2017

An epigenome-wide association analysis of cardiac autonomic responses among a population of welders

ABSTRACT DNA methylation is one of the potential epigenetic mechanisms associated with various adverse cardiovascular effects; however, its association with cardiac autonomic dysfunction, in particular, is unknown. In the current study, we aimed to identify epigenetic variants associated with alterations in cardiac autonomic responses. Cardiac autonomic responses were measured with two novel markers: acceleration capacity (AC) and deceleration capacity (DC). We examined DNA methylation levels at more than 472,506 CpG probes through the Illumina Infinium HumanMethylation450 BeadChip assay. We conducted separate linear mixed models to examine associations of DNA methylation levels at each CpG with AC and DC. One CpG (cg26829071) located in the GPR133 gene was negatively associated with DC values after multiple testing corrections through false discovery rate. Our study suggests the potential functional importance of methylation in cardiac autonomic responses. Findings from the current study need to be replicated in future studies in a larger population