Different glomerular filtration rate estimating formula for prescribing DOACs in oldest patients: appropriate dosage and bleeding risk. Post hoc analysis of a prospective cohort

Background

Direct oral anticoagulants (DOACs) pharmacokinetics depends on estimated glomerular filtration rate (eGFR), whose estimation is crucial for optimal risk/benefit balance.

Aims

To assess the concordance among different eGFR formulas and the potential impact on DOACs prescription appropriateness and bleeding risk in oldest hospitalized patients.

Methods

Post hoc analysis of a single-centre prospective cohort study. eGFR was calculated by creatinine-based (MDRD, CKD-EPI_Cr, BIS₁) and creatinine–cystatin-C-based (CKD-EPI_Comb and BIS₂) formulas. Patients were stratified according to eGFR [severely depressed (SD) 15–29; moderately depressed (MD) 30–49; preserved/mildly depressed (PMD): ≥ 50 ml/min/1.73 m²]. Concordance between the different equations was assessed by Cohen’s kappa coefficient.

Results

Among AF patients, 841 (59.2% women, mean age 85.9 ± 6.5 years) received DOACs. By CKD-EPI_Cr equation, 135 patients were allocated in the SD, 255 in the MD and 451 in the PMD group. The concordance was excellent only between BIS 2 and CKD-EPI_Comb and MDRD and CKD-EPI_Cr, while was worse (from good to poor) between the other formulas. Indeed, by adding cystatin-C almost over 1/3 of the patients were reallocated to a worse eGFR class. Bleeding prevalence increased by 2–3% in patients with discordant eGFR between formulas, reallocated to a worse chronic kidney disease (CKD) stage, although without reaching statistical significance. CKD-EPI_Comb resulted the best predictor of bleeding events (AUROC 0.71, p = 0.03).

Discussion

This study highlights the variability in CKD staging according to different eGFR formulas, potentially determining inappropriate DOACs dosing. Although the cystatin-C derived CKDEPI_Comb equation is the most accurate for stratifying patients, BIS₁ may represent a reliable alternative.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-021-01986-w.

Long-term effectiveness and safety of anticoagulation therapy in oldest old, frail people with atrial fibrillation

BACKGROUND

Atrial Fibrillation (AF) represents a major cause of mortality and morbidity in older people; however, oldest-old frail patients are usually excluded from clinical trials. Aim of the study is to evaluate the impact of oral anticoagulation (OAC) therapy on long-term overall survival and clinically relevant bleedings in a large cohort of hospitalised frail, oldest-old patients with AF.

PATIENTS AND METHODS

Prospective, observational, cohort study, evaluating patients consecutively hospitalized for acute illnesses in our Geriatrics Unit (January 2013-July 2017). Participants were divided in two groups, AF and sinus rhythm (SR). Besides recording demographic characteristics and clinical history, comprehensive geriatric assessment (CGA) was obtained.

RESULTS

AF patients [1808/5093 (35.5%), 58.5% women] were older, with higher burden of comorbidity than those with SR. At discharge, HAS-BLED [OR 0.77 (95%CI 0.67-0.90), cognitive impairment [OR 0.92 (95%CI 0.90-0.95)], malnutrition [OR 0.74 (95%CI 0.57-0.97)] and CHA2DS2VASc [OR 1.33 (95%CI 1.20-1.47)] emerged as significant independent predictors of anticoagulant prescription. AF patients showed significantly reduced overall survival (OS) than those with SR (11.4 vs 19.4 months, p<.001). However, anticoagulated AF patients (75.2%) had three-times longer OS than those not anticoagulated (15.0 vs 5.6 months, p<.001), comparable to SR patients after adjustment for potential confounders [HR 1.04 (95%CI 0.99-1.10)]. ED readmittance risk for clinically relevant bleeding did not differ between AF patients receiving or not anticoagulation [HR 1.04 (95%CI 0.76-1.14)] CONCLUSION: anticoagulation therapy was associated with significant increase of long-term OS without increased risk of clinically relevant bleeding. CGA resulted an useful tool in OAC therapy decision-making.

Abstract 068: Ghrelin Restores Nitric Oxide Availability In The Forearm Microcirculation Of Essential Hypertensive Patients

Objective: Essential hypertensive patients (EH) are characterized by endothelial dysfunction caused by a reduced nitric oxide (NO) availability due to reactive oxygen species excess and low-grade inflammatory condition. Ghrelin is a recently identified growth hormone-releasing peptide, with recognized cardiovascular actions. Possible effects on endothelial dysfunction have been never investigated in EH. In this study we evaluated whether exogenous ghrelin can improve endothelial dysfunction in the forearm microcirculation of untreated mild-moderate EH.

Methods: In 9 EH (51.8±8.1 yrs) and 9 normotensive subjects (NS, 50.5±3.5 yrs), we studied the forearm blood flow (FBF, strain-gauge plethysmography) response to intrabrachial acetylcholine (ACh, 0.15-15 mg/100 ml/min) with and without NO synthase blockade by L-NMMA (100 μg/100 ml/min), or the antioxidant vitamin (Vit) C (8 mg/100 ml/min). The protocol was repeated under exogenous ghrelin intra-arterial infusion (200 ng/min, 30’ pre-infusion).

Results: In NS, maximal vasodilation (VD) to ACh (480±20%) was inhibited by L-NMMA (292±22, -39±7%; P<0.001) and unchanged by Vit C (482±34%). Ghrelin failed to modify these vascular responses. In EH, VD to ACh was blunted vs NS (337±45%; P<0.001) and resistant to L-NMMA (313±32, -7±3%). Vit C increased the response to ACh (509±57%; P<0.01 vs ACh alone) and restored the inhibiting effect of L-NMMA (332±42, -34±8%; P<0.001). Ghrelin, while not modifying the basal FBF, it increased (P<0.001) the VD to ACh (448±55%) and restored the inhibitory effect of L-NMMA on ACh (355±43, -20±6%; P<0.001). Vit C only slightly improved VD to ACh under ghrelin infusion (486±45%). In EH ghrelin significantly (P<0.05) decreased plasma venous malodialdehyde (from 6.9±1.5 to 5.2±1.0 μmol/L), lipoperoxides (from 9.1±1.9 to 6.6±2.3 μmol/L) and IL-6 (from 11.1±0.6 to 9.3±1.0 pg/mL) and increased plasma antioxidant capacity (from 407±109 to 630±97 mmol/L). Response to sodium nitroprusside was similar between EH and NS and not affected by ghrelin.

Conclusions: Exogenous ghrelin is able to ameliorate endothelial dysfunction by restoring NO availability in the forearm microcirculation of EH, an effect probably determined by antioxidant and/or anti-inflammatory activities.

Impact of inflammation on vascular disease in hypertension

Low grade inflammation exerts a crucial pathogenic role in hypertension and cardiovascular disease. A large body of evidence indicates that innate and adaptive immune systems, and in particular T cells, are involved. A balance between T-effector lymphocytes and Treg lymphocytes represents a crucial regulatory mechanism that, when altered, favours blood pressure elevation and organ damage development. Of note, Treg lymphocytes exert important anti-inflammatory properties, whose activities guarantees vascular homeostasis and protects the vessel wall from the development of atherosclerosis. In humans, most of evidence ascertaining essential hypertension as a condition of chronic low-grade inflammatory status revealed a strict and independent association between CRP, TNF-α, IL-6 or adhesion molecules and vascular changes in essential hypertensive patients. Evidence of involvement of the immune system in vasculature from patients with hypertension or cardiovascular disease starts to appear in literature. Further investigation on immunity, including the role of T-lymphocytes, will help develop of new therapeutic targets that may improve outcomes in hypertension and cardiovascular disease and discover novel approaches in the treatment of hypertension and vascular disease.

Tumour necrosis factor-alpha participates on the endothelin-1/nitric oxide imbalance in small arteries from obese patients: role of perivascular adipose tissue

AIMS

We assessed the impact of vascular and perivascular tumour necrosis factor-alpha (TNF-α) on the endothelin (ET)-1/nitric oxide (NO) system and the molecular pathways involved in small arteries from visceral fat of obese patients (Obese) and Controls.

METHODS AND RESULTS

Isolated small arteries from 16 Obese and 14 Controls were evaluated on a pressurized micromyograph. Endogenous ET-1 activity was assessed by the ETA blocker BQ-123. TNF-α and NO were tested by anti-TNF-α infliximab (IFX) and N(ω)-nitro-l-arginine methylester (L-NAME). Gene and protein expression of TNF-α, ET-1, ETA, and ETB receptors were determined by RT-PCR and IHC on arterial wall and in isolated adipocytes. Obese showed a blunted L-NAME-induced vasoconstriction, which was potentiated by IFX, and an increased relaxation to BQ-123, unaffected by L-NAME but attenuated by IFX. Perivascular adipose tissue (PVAT) removal reversed these effects. Obese showed intravascular superoxide excess, which was decreased by apocynin (NAD(P)H oxidase inhibitor), L-NAME, and BQ-123 incubations, and abolished by IFX. An increased vascular expression of ET-1, ETA, and ETB receptors, and higher vascular/perivascular TNF-α and TNF-α receptor expression were also detected. The arterial expression and phosphorylation of c-Jun N-terminal kinase (JNK) were higher in Obese vs. Controls, and downregulated by IFX.

CONCLUSIONS

In small arteries of Obese, PVAT-derived TNF-α excess, and an increased vascular expression of ET-1 and ETA receptor, contribute to the ET-1/NO system imbalance, by impairing tonic NO release. Reactive oxygen species excess, via NAD(P)H oxidase activation, induces the endothelial nitric oxide synthase uncoupling, which in turn generates superoxide and impairs NO production. The up-regulated JNK pathway represents a crucial molecular signalling involved in this process.

Abstract 85: Low-grade Inflammation Participates on the Enhanced Vasoconstriction to the Endogenous Endothelin-1 in Small Vessels From Obese Patients

Objective: Obesity is characterized by vascular low-grade inflammation, with an augmented endogenous endothelin(ET)-1-mediated vasoconstriction (VC) and a blunted tonic nitric oxid(NO)-mediated relaxation (VD). We evaluated whether TNF-α, localized in the vascular wall and in perivascular adipocytes (PVA), contributes to the VC induced by endogenous ET-1 and whether this action is mediated by an effect on tonic NO release in small resistance arteries from obese patients (Ob) and controls (Ctrl).

Method: Sample of visceral fat were obtained in 14 Ob (BMI:42.1±3.7) and 14 Ctrl (BMI:25.4±3.6), matched for metabolic profile and blood pressure values, undergoing laparoscopic surgical procedure. Small arteries were investigated on a pressurized micromyograph. Endogenous ET-1 was assessed by vascular response to BQ-123. TNF-α and NO were assessed by Infliximab (IFX) and L-NAME, respectively. Gene and protein expression of TNF-α, ET-1 and ETA receptors were determined by RT-PCR (gene/reference) and IHC (AU) on arterial wall and in PVA.

Results: In Ctrl, L-NAME-induced VC (15.5±0.6%) was not affected by IFX (15.1±0.4%). In contrast, Ob showed a blunted VC to L-NAME (6.0±0.7%; P<0.01 vs Ctrl) which was potentiated (P<0.01) by IFX (12.5±0.8%). In Ob, the VD to BQ-123 (47.0±1.5%) was attenuated (P<0.01) by IFX (29.1±2.4%) and not affected by L-NAME (43,3±0.6%). During IFX co-infusion, L-NAME further reduced the VD to BQ-123 (19.4±3.0%; P<0.01 vs BQ-123+IFX). In Ctrl, VD to BQ-123 was blunted (26.3±1.3%; P<0.01 vs Ob), not affected by IFX (24.1±0.6%) and significantly reduced by L-NAME (12.3±1.1%). Ob showed a significant overexpression of TNF-α respect to Ctrl, either at the level of arterial wall (24.9±19.6 vs 2.8±2.5 AU, P<0.001) or in PVA (2.9±1.8 vs 1.2±0.7 gene/reference, P<0.005). These results were paralleled by a higher arterial expression of ET-1 (45.8±10.3 vs 24.3±15.0 AU, P<0.01) and ETA receptors (69.4±6.0 vs 9.6±2.8 AU, P<0.001) in Ob vs Ctrl.

Conclusion: Small vessels of Ob show an enhanced ETA-mediated VC and a blunted NO-mediated VD. An excess of vascular and perivascular TNF-α, coupled with an increased expression of ET-1 and ETA in the vasculature of Ob, contributes to the enhanced ET-1-mediated VC tone partly by an impairment of tonic NO release.