Vascular Disease and Risk Stratification for Ischemic Stroke and All-Cause Death in Heart Failure Patients without Diagnosed Atrial Fibrillation: A Nationwide Cohort Study

C21 preserves endothelial function in the thoracic aorta from DIO mice: role for AT2, Mas and B2 receptors

Compound 21 (C21), a selective agonist of angiotensin II type 2 receptor (AT2R), induces vasodilation through NO release. Since AT2R seems to be overexpressed in obesity, we hypothesize that C21 prevents the development of obesity-related vascular alterations. The main goal of the present study was to assess the effect of C21 on thoracic aorta endothelial function in a model of diet-induced obesity (DIO) and to elucidate the potential cross-talk among AT2R, Mas receptor (MasR) and/or bradykinin type 2 receptor (B2R) in this response. Five-week-old male C57BL6J mice were fed a standard (CHOW) or a high-fat diet (HF) for 6 weeks and treated daily with C21 (1 mg/kg p.o) or vehicle, generating four groups: CHOW-C, CHOW-C21, HF-C, HF-C21. Vascular reactivity experiments were performed in thoracic aorta rings. Human endothelial cells (HECs; EA.hy926) were used to elucidate the signaling pathways, both at receptor and intracellular levels. Arteries from HF mice exhibited increased contractions to Ang II than CHOW mice, effect that was prevented by C21. PD123177, A779 and HOE-140 (AT2R, Mas and B2R antagonists) significantly enhanced Ang II-induced contractions in CHOW but not in HF-C rings, suggesting a lack of functionality of those receptors in obesity. C21 prevented those alterations and favored the formation of AT2R/MasR and MasR/B2R heterodimers. HF mice also exhibited impaired relaxations to acetylcholine (ACh) due to a reduced NO availability. C21 preserved NO release through PKA/p-eNOS and AKT/p-eNOS signaling pathways. In conclusion, C21 favors the interaction among AT2R, MasR and B2R and prevents the development of obesity-induced endothelial dysfunction by stimulating NO release through PKA/p-eNOS and AKT/p-eNOS signaling pathways.

Usefulness of CHA2DS2-VASc Score to Predict Stroke Risk Independent of Atrial Fibrillation

The CHA₂DS₂-VASc score is used to predict stroke risk among patients with atrial fibrillation (AF). We examined whether a CHA₂DS₂-VASc score predicts stroke risk among individuals without hospital-diagnosed AF and quantified the magnitude of the association in comparison to AF patients. We used data from population-based medical registries (1995 to 2005) covering all Danish hospitals to identify patients diagnosed with AF (n = 122,980). We matched ≤5 non-AF individuals (n = 612,723) to each AF patient on the individual risk factors included in the CHA₂DS₂-VASc score. We calculated 10-year absolute risk of ischemic and all-cause stroke in AF and non-AF individuals and compared the stroke risk between cohorts within strata of CHA₂DS₂-VASc scores using Cox regression. The 10-year risk of ischemic/all-cause stroke was 4.4%/8.8% among non-AF individuals and 6.2%/12% in AF patients, corresponding to a risk difference of 1.8% for ischemic stroke and 3.3% for all-cause stroke. In both cohorts, the stroke risk correlated with increasing CHA₂DS₂-VASc scores. However, in individuals with CHA₂DS₂-VASc scores ≥5 who were <75 years or male, the absolute risk of ischemic stroke in individuals without AF exceeded the risk in AF patients. In the same subgroups, the hazard ratio approached unity. Similar results were observed for all-cause stroke. The CHA₂DS₂-VASc score was associated with 10-year stroke risk also among individuals without hospital-diagnosed AF. In conclusion, primary prophylactic anticoagulation therapy may be relevant in male and younger non-AF individuals with CHA₂DS₂-VASc scores ≥5. These findings should be confirmed in clinical trials.

Heart Failure and Stroke

PURPOSE

Ischemic stroke significantly contributes to morbidity and mortality in heart failure (HF). The risk of stroke increases significantly, with coexisting atrial fibrillation (AF). An aggravating factor could be asymptomatic paroxysms of AF (so-called silent AF), and therefore, the risk stratification in these patients remains difficult. This review provides an overview of stroke risk in HF, its risk stratification, and stroke prevention in these patients.

RECENT FINDINGS

Stroke risk stratification in HF patients remains an important issue. Recently, the CHA₂DS₂-VASc score, originally developed to predict stroke risk in AF patients, had been reported to be a predictive for strokes in HF patients regardless of AF being present. Furthermore, there are several independent risk factors (e.g., hypertension, diabetes mellitus, prior stroke) described. Based on the current evidence, HF should be considered as an independent risk factor for stroke. The CHA₂DS₂-VASc score might be useful to predict stroke risk in HF patients with or without AF in clinical routine. However, there is only a recommendation for the oral anticoagulation use in patients with concomitant HF and AF, while in patients with HF and no AF, individualized risk stratification is preferred. Current guidelines recommend to prefer non-vitamin Kantagonist anticoagulants over warfarin.

Operationalizing a frailty index using routine blood and urine tests

Background

Uncomplicated frailty instruments are desirable for use in a busy clinical setting. The aim of this study was to operationalize a frailty index (FI) from routine blood and urine tests, and to evaluate the properties of this FI compared to other frailty instruments.

Materials and methods

We conducted a secondary analysis of a prospective cohort study on 306 patients aged ≥65 years hospitalized on geriatric wards. An FI comprising 22 routine blood parameters and one standard urine parameter (FI-Lab), a 50-item FI based on a comprehensive geriatric assessment (FI-CGA), a combined FI (FI-combined [items from the FI-Lab + others from the FI-CGA]), the Clinical Frailty Scale, rule-based frailty definition, and frailty phenotype were operationalized from data obtained during patients’ hospital stays (ie, before discharge [baseline examination]). Follow-up data were obtained up to 1 year after the baseline examination.

Results

The mean FI-Lab score was 0.34±15, with an upper limit of 0.74. The FI-Lab was correlated with all the other frailty instruments (all P<0.001). The FI-Lab revealed an area under the receiver-operating characteristic curve (AUC) for 6-month and 1-year mortality of 0.765 (0.694–0.836) and 0.769 (0.706–0.833), respectively (all P<0.001). Each 0.01 increment in FI-Lab increased the risk (adjusted for age and sex) for 6-month and 1-year mortality by 7.2% and 7.1%, respectively (all adjusted P<0.001). When any of the other FIs (except the FI-combined) were also included in the models, each 0.01 increment in FI-Lab score was associated with an increase in the risk of 6-month and 1-year mortality by 4.1%–5.4% (all adjusted P<0.001).

Conclusion

The FI-Lab showed key characteristics of an FI. The FI-Lab can be applied as a single frailty measure or in combination with/in addition to other frailty instruments.

Cirrhosis patients' stroke risks and adverse outcomes: Two nationwide studies

BACKGROUND & AIMS

The association between liver cirrhosis (LC) and stroke is not completely understood. Our purpose was to evaluate stroke risk and post-stroke outcomes in patients with LC.

METHODS

We identified 6944 adults aged 20 years and older, newly diagnosed with LC, using the Taiwan's National Health Insurance Research Database from 2000 to 2005. The comparison cohort consisted of 27,776 adults without LC, randomly selected by frequency matching in age and sex. Events of new-onset stroke were identified from medical claims during the 2000-2013 follow-up period. Adjusted hazard ratios (HR) and 95% confidence intervals (CIs) of stroke associated with LC were calculated in the multiple Cox proportional hazard model. Another nested stroke cohort study of 21,267 hospitalized stroke patients analyzed adjusted odds ratios (ORs) and 95% CIs of adverse events after stroke, among patients with and without LC, between 2000 and 2009.

RESULTS

The incidences of stroke for people with and without LC were 6.1 and 4.3 per 1000 person-years, respectively. Compared with the non-cirrhotic cohort, the adjusted HR of stroke was 1.55 (95% CI 1.28-1.87) for LC patients. Previous LC was associated with risks of epilepsy (OR 1.30, 95% CI 1.09-1.56), admission to intensive care unit (OR 1.23, 95% CI (1.14-1.32) and in-hospital mortality (OR 1.83, 95% CI 1.63-2.05) after stroke.

CONCLUSIONS

LC was associated with higher risk of stroke, and patients with LC had more complications and mortality after stroke. This susceptible population needs strategies to prevent stroke and post-stroke adverse events.