Effects of enhanced versus reduced vasodilating treatment on brachial and central blood pressure in patients with chronic kidney disease: a randomized controlled trial

Aortic Calcification is Associated With the Difference Between Invasive Central and Cuff-Measured Brachial Blood Pressure in Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) is associated with accelerated vascular calcification and increased central systolic blood pressure when measured invasively (invCSBP) relative to cuff-based brachial systolic blood pressure (cuffSBP). The contribution of aortic wall calcification to this phenomenon has not been clarified. We, therefore, examined the effects of aortic calcification on cuffSBP and invCSBP in a cohort of patients representing all stages of CKD.

METHODS

During elective coronary angiography, invCSBP was measured in the ascending aorta with a fluid-filled catheter with simultaneous recording of cuffSBP using an oscillometric device. Furthermore, participants underwent a non-contrast computed tomography scan of the entire aorta with observer-blinded calcification scoring of the aortic wall ad modum Agatston.

RESULTS

We included 168 patients (mean age 67.0 ± 10.5, 38 females) of whom 38 had normal kidney function, while 30, 40, 28, and 32 had CKD stages 3a, 3b, 4, and 5, respectively. Agatston scores adjusted for body surface area ranged from 48 to 40,165. We found that invCSBP increased 3.6 (95% confidence interval 1.4-5.7) mm Hg relative to cuffSBP for every 10,000-increment in aortic Agatston score. This association remained significant after adjustment for age, diabetes, antihypertensive treatment, smoking, eGFR, and BP level. No such association was found for diastolic BP.

CONCLUSIONS

Patients with advanced aortic calcification have relatively higher invCSBP for the same cuffSBP as compared to patients with less calcification. Advanced aortic calcification in CKD may therefore result in hidden central hypertension despite apparently well-controlled cuffSBP. ClinicalTrials.gov identifier: NCT04114695.

Urinary acid-base excretion deciphers high acid load from colonic bicarbonate loss in intestinal failure patients with ileocolonic anastomosis - Guidance for composition of parenteral support

BACKGROUND & AIMS

Acid-base disturbances are common in short bowel (SB) patients due to increased intestinal bicarbonate loss. However, the resulting systemic acid load has not been quantified. Base excess is used to monitor metabolic acid-base disturbances but inadequately reflects the acid load. Our aim was to investigate the systemic acid/base load in SB-patients to obtain quantitative estimates to guide the composition of parenteral support.

METHODS

We calculated total acid load in SB patients by summing 24-h urinary net acid excretion (NAE) and the provision of base equivalents in parenteral support. We then compared differences among anatomical SB-types: jejunostomy (SB-J), jejunocolostomy (SB-JC), and jejunoileostomy (SB-JIC). 47 urine samples from 34 SB patients were analyzed for bicarbonate (HCO3-), ammonium (NH4+), and titratable acid (TA) concentrations. NAE was calculated as (TA + NH4+) - HCO3-. Mixed-effects repeated-measures models were used to statistically examine differences between SB-types and associations with parenteral nutrition and NAE. A healthy cohort served as control.

RESULTS

In comparison to SB-J, SB-JC patients had a 4.1 mmoL/l lower base excess (95% CI: -6.3 to -1.8) and an 84.5 mmol/day higher total acid load (CI: 41.3 to 127.7). There were no significant differences between SB-JIC and SB-J regarding base excess, NAE, or total acid load. Higher amounts of infused acetate, sodium, and chloride, but not the acetate/chloride ratio, were associated with lower NAE and higher base excess.

CONCLUSIONS

Due to increased colonic bicarbonate loss, patients with SB-JC have a ∼4.4-fold higher acid load than healthy controls. The ion transport mechanisms mediating this bicarbonate loss from the remaining colon need further experimental investigation. NAE could be a useful tool to adjust base infusion in SB.

Prediction of CKD Progression and Cardiovascular Events Using Albuminuria and Pulse Wave Velocity

INTRODUCTION

Chronic kidney disease (CKD) is associated with cardiovascular disease (CVD) and death. Albuminuria is an established risk factor, but additional biomarkers predicting CKD progression or CVD are needed. Arterial stiffness is an easily measurable parameter that has been associated with CVD and mortality. We evaluated the ability of carotid-femoral pulse wave velocity (PWV) and urine albumin-creatinine (UAC) ratio to predict CKD progression, cardiovascular events, and mortality in a cohort of CKD patients.

METHODS

In CKD stage 3-5 patients, PWV and UAC were measured at baseline. CKD progression was defined as 50% decline in estimated glomerular filtration rate (eGFR), initiation of dialysis, or renal transplantation. A composite endpoint was defined as CKD progression, myocardial infarction, stroke, or death. Endpoints were analyzed using Cox regression analysis adjusted for possible confounders.

RESULTS

We included 181 patients (median age 69 [interquartile range 60-75] years, 67% males) with a mean eGFR of 37 ± 12 mL/min/1.73 m2 and UAC 52 (5-472) mg/g. Mean PWV was 10.6 m/s. Median follow-up until first event was 4 (3-6) years with 44 and 89 patients reaching a CKD progression or composite endpoint, respectively. UAC (g/g) significantly predicted both CKD progression (HR 1.5 [1.2; 1.8]) and composite endpoints (HR 1.4 [1.1; 1.7]) in adjusted Cox regression. In contrast, PWV (m/s) was not associated with neither CKD progression (HR 0.99 [0.84; 1.18]) nor the composite endpoint (HR 1.03 [0.92; 1.15]).

CONCLUSION

In an aging CKD population, UAC predicted both CKD progression and a composite endpoint of CKD progression, cardiovascular events, or death, while PWV did not.

Invasive validation of the Antares algorithm for determining central blood pressure based on upper arm oscillometric pulse waves in patients with type 2 diabetes

INTRODUCTION

Antares is a pulse wave analysis (PWA) algorithm designed to allow a non-invasive estimation of central (aortic) blood pressure (cBP) using automated oscillometric blood pressure (BP) devices. Diabetes may affect elastic and muscular arteries differently, resulting in disparate pulse wave characteristics in central and peripheral arteries, which may limit the accuracy of PWA devices. The aim of our study was to evaluate the accuracy of Antares for estimating cBP as compared with invasively measured cBP in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

In this study, consecutive patients undergoing elective coronary angiography were recruited between November 2017 and September 2020. In 119 patients with type 2 diabetes, cBP was measured invasively and simultaneously determined non-invasively using the custo screen 400 device with the integrated Antares algorithm.

RESULTS

The mean difference between the estimated and invasively measured cBP was 1.2±6.3 mmHg for central systolic BP (cSBP), 1.0±4.3 mmHg for central mean arterial pressure (cMAP) and 3.6±5.7 mmHg for central diastolic BP (cDBP). High correlations were found between estimated cBP and invasively measured cBP (cSBP: r=0.916; cMAP: r=0.882; cDBP: r=0.791; all p<0.001).

CONCLUSIONS

The present study suggests that the Antares algorithm incorporated into the custo screen 400 device can estimate cBP with high accuracy turning a conventional oscillometric BP device into a type II device for the non-invasive estimation of cBP, which is applicable in patients with type 2 diabetes. Integration of Antares into commercially available BP devices could facilitate the introduction of cBP into routine clinical practice as a part of disease and risk management.