The Relationship of Kidney Function, Cardiovascular Morbidity, and All-Cause Mortality: a Prospective Primary Care Cohort Study.

BACKGROUND: Lower-than-normal estimated glomerular filtration rate (eGFR) is associated with the risk for all-cause mortality and adverse cardiovascular events. In this regard, the role of higher-than-normal eGFR is still controversial. OBJECTIVE: Investigate long-term clinical consequences across the levels of eGFR calculated by the creatinine-based Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation among apparently healthy cardiovascular risk subjects. DESIGN: Prospective study. PARTICIPANTS: Participants (n=1747) of a population-based screening and intervention program for cardiovascular risk factors in Finland during the years 2005-2007. MAIN MEASURES: Cardiovascular morbidity and all-cause mortality. KEY RESULTS: Over the 14-year follow-up, subjects with eGFR ≥105 ml/min/1.73 m2 (n=97) had an increased risk for all-cause mortality [HR 2.15 (95% CI: 1.24-3.73)], incident peripheral artery disease [HR 2.62 (95% CI: 1.00-6.94)], and atrial fibrillation/flutter [HR 2.10 (95% CI: 1.21-3.65)] when compared to eGFR category 90-104 ml/min after adjustment for cardiovascular and lifestyle-related risk factors. The eGFR category ≥105 ml/min was also associated with a two-fold increased mortality rate compared to the Finnish general population. CONCLUSIONS: Renal hyperfiltration defined as eGFR ≥105 ml/min/1.73 m2 is a frequent and important finding in patients commonly treated in primary care. These patients should be followed closely for timely interventions, such as strict BP and blood glucose regulation.

Asystole episodes and bradycardia in patients with end-stage renal disease.

BACKGROUND: Knowledge of arrhythmias in patients with end-stage renal disease (ESRD) is mainly based on ambulatory electrocardiography (ECG) studies and observations during haemodialysis (HD). We used insertable cardiac monitors (ICMs) to define the prevalence of arrhythmias, focusing on bradyarrhythmias, in ESRD patients treated with several dialysis modes including home therapies. Moreover, we assessed whether these arrhythmias were detected in baseline or ambulatory ECG recordings. METHODS: Seventy-one patients with a subcutaneous ICM were followed for up to 3 years. Asystole (≥4.0 s) and bradycardia (heart rate <30 bpm for ≥4 beats) episodes, ventricular tachyarrhythmias and atrial fibrillation (AF) were collected and verified visually. A baseline ECG and a 24- to 48-h ambulatory ECG were recorded at recruitment and once a year thereafter. RESULTS: At recruitment, 44 patients were treated in in-centre HD, 12 in home HD and 15 in peritoneal dialysis. During a median follow-up of 34.4 months, 18 (25.4%) patients had either an asystolic or a bradycardic episode. The median length of each patient's longest asystole was 6.6 s and that of a bradycardia 13.5 s. Ventricular tachyarrhythmias were detected in 16 (23%) patients, and AF in 34 (51%) patients. In-centre HD and Type II diabetes were significantly more frequent among those with bradyarrhythmias, whereas no bradyarrhythmias were found in home HD. No bradyarrhythmias were evident in baseline or ambulatory ECG recordings. CONCLUSIONS: Remarkably many patients with ESRD had bradycardia or asystolic episodes, but these arrhythmias were not detected by baseline or ambulatory ECG.

Fluid overload is an independent predictor of atrial fibrillation in end-stage renal disease: A prospective study using insertable cardiac and body composition monitors
.

BACKGROUND: Fluid overload and atrial fibrillation (AF) are frequently encountered in patients with end-stage renal disease (ESRD). We used subcutaneously insertable cardiac monitors (ICM) to detect AF and associated it with the hydration status, determined with a body composition monitor (BCM) in dialysis patients. MATERIALS AND METHODS: 69 patients were recruited. Fluid overload was defined based on BCM measurements as a ratio of overhydration (OH) and extracellular water (OH/ECW) of > 15% at baseline. AF episodes lasting ≥ 2 minutes were collected. RESULTS: 45 in-center hemodialysis patients, 11 on peritoneal dialysis, 12 on home hemodialysis, and 1 predialysis-stage patient were followed up for a median of 2.9 years (25th - 75th percentile 1.9 - 3.1). 29% were overhydrated at baseline, and the percentage remained similar throughout the study. Overhydrated patients had a lower body mass index, a higher prevalence of type 1 diabetes mellitus (DM) and diabetic nephropathy, higher systolic blood pressure, greater ultrafiltration (UF) during dialysis, and a smaller lean tissue index than normohydrated patients. Chronic or paroxysmal AF was known to occur in 20.3% at entry, and a further 33.3% developed AF during the study, with an overall prevalence 53.6%. In univariable logistic regression, OH/ECW > 15% was strongly associated with AF prevalence (OR 6.8, 95% CI 1.7 - 26.5, p = 0.006), as were UF, age, coronary heart disease (CHD), DM, and the echocardiogram-derived ejection fraction and left atrial diameter. In multivariable analyses, OH/ECW > 15% remained an independent predictor of AF alongside age and CHD. CONCLUSION: The occurrence of AF is independently associated with BCM-measured fluid overload, which is common among ESRD patients.

The effect of isolated ultrafiltration on Doppler-derived indices of left ventricular diastolic function.

BACKGROUND: Haemodialysis (HD) is associated with acute changes simultaneously in fluid status (ultrafiltration) and in many biochemical parameters (dialysis). Reports on the effects of these changes on left ventricular (LV) diastolic function are scant. This study evaluated the effect of isolated ultrafiltration (UF) and subsequent HD with minimal fluid removal on Doppler-derived indices of LV diastolic function in patients who were asymptomatic and stable on HD. METHODS: In 11 HD cases, the 5 h treatment session was divided into a 2.5 h period of fluid removal without dialysis (UF phase) and 2.5 h of dialysis with minimal fluid removal (HD phase). We examined the following parameters of LV diastolic function echocardiographically: early rapid filling (Emax), atrial peak filling (Amax), Emax/Amax ratio, isovolumic relaxation time (IVRT) and deceleration time of the E-wave (DT). RESULTS: During the UF phase, Emax decreased from 0.82 +/- 0.2 to 0.62 +/- 0.2 m/s (P = 0.003), Amax decreased from 0.72 +/- 0.2 to 0.63 +/- 0.2 m/s (P = 0.042) and the ratio Emax/Amax did not change (P = NS). During the HD phase, Emax increased from 0.62 +/- 0.2 to 0.72 +/- 0.2 m/s (P = 0.018), Amax increased from 0.63 +/- 0.2 to 0.70 +/- 0.3 m/s (P = NS) and the Emax/Amax ratio remained unchanged (P = NS). IVRT was prolonged in 10 out of 11 patients at the start of the UF phase and it was further prolonged from 142 +/- 40 to 171 +/- 55 ms (P = 0.03) during the UF phase. IVRT did not alter during the HD phase (P = NS). During the UF phase, DT increased from 175 +/- 83 to 244 +/- 119 and it decreased from 244+/-119 to 209 +/- 98 in the HD phase, but both changes were statistically insignificant. No statistically significant correlations were observed between the changes in the Doppler indices of diastolic function and changes in biochemical parameters during the HD phase. CONCLUSIONS: UF affects the parameters Emax, Amax and IVRT used to evaluate LV diastolic function. The changes in Emax and Amax during the HD phase are due to fluid refilling from tissues into the blood space, HD as such having no effect on Doppler indices. However, isolated UF or HD does not affect the Emax/Amax ratio. Emax and IVRT seem to be the most volume-sensitive parameters.