Renal function and aspirin resistance in patients with coronary artery disease

N-Terminal Pro-Brain Natriuretic Peptide and Right Ventricular Diameter Are Related to Aspirin Resistance in Coronary Artery Disease Patients

Background and Objectives: Resistance to ASA (ASAres) is a multifactorial phenomenon defined as insufficient reduction of platelet reactivity through incomplete inhibition of thromboxane A2 synthesis. The aim is to reassess the prevalence and predictors of ASAres in a contemporary cohort of coronary artery disease (CAD) patients (pts) on stable therapy with ASA, 75 mg o.d. Materials and Methods: We studied 205 patients with stable CAD treated with daily dose of 75 mg ASA for a minimum of one month. ASAres was defined as ARU (aspirin reaction units) ≥550 using the point-of-care VerifyNow Aspirin test. Results: ASAres was detected in 11.7% of patients. Modest but significant correlations were detected between ARU and concentration of N-terminal pro-brain natriuretic peptide (NT-proBNP) (r = 0.144; p = 0.04), body weight, body mass index, red blood cell distribution width, left ventricular mass, and septal end-systolic thickness, with trends for left ventricular mass index and prothrombin time. In multivariate regression analysis, log(NT-proBNP) was identified as the only independent predictor of ARU—partial r = 0.15, p = 0.03. Median concentrations of NT-proBNP were significantly higher in ASAres patients (median value 311.4 vs. 646.3 pg/mL; p = 0.046) and right ventricular diameter was larger, whereas mean corpuscular hemoglobin concentration was lower as compared to patients with adequate response to ASA. Conclusions: ASAres has significant prevalence in this contemporary CAD cohort and NT-proBNP has been identified as the independent correlate of on-treatment ARU, representing a predictor for ASAres, along with right ventricular enlargement and lower hemoglobin concentration in erythrocytes.

Association between renal function and platelet reactivity during aspirin therapy in elderly patients with atherosclerotic cardiovascular disease

Background

Aspirin is the key treatment in the secondary prevention of atherosclerotic cardiovascular disease. High on-treatment platelet reactivity (HTPR) to aspirin has been reported to partially account for the enhanced risk of thrombotic events. In particular, HTPR has been described more frequently among elderly patients. The aim of this study was to identify the clinical and biological factors associated with HTPR in a real-life elderly population.

Methods

In this retrospective study, elderly patients with atherosclerotic cardiovascular disease on regular aspirin treatment were enrolled. Cardiovascular risk factors, routine biological parameters, comorbidities, and concomitant medications were recorded. The upper quartile of the platelet aggregation rate, determined by light transmission aggregometry with arachidonic acid, was defined as the HTPR group.

Results

A total of 304 patients were included (mean age 77 ± 8 years, 76% men). Patients in the HTPR group were older than the patients in the non-HTPR group (mean age: 79 ± 7 vs. 76 ± 8 years, p = 0.008). Patients with moderately decreased estimated glomerular filtration rate (eGFR) had a higher frequency of HTPR than patients with slightly decreased eGFR or normal eGFR (35.8, 22.5, 12.2%, respectively, p < 0.05). In multivariate analysis, an independent risk factor for HTPR was the eGFR (OR: 0.984, 95% CI: 0.980–0.988, p < 0.001).

Conclusions

Advanced age and decreased eGFR are correlated with poor pharmacodynamic response to aspirin.

Factors Influencing Aspirin Hyporesponsiveness in Elderly Chinese Patients

Background

Aspirin hyporesponsiveness increases the risk of ischemic events. Therefore, it is important to investigate the factors influencing aspirin hyporesponsiveness.

Material/Methods

Patients aged 60 years or older who did not take aspirin before enrollment were included, with aspirin 100 mg/day administered after enrollment. The arachidonic acid-induced platelet aggregation rate (Ara) was measured by light transmission assay to evaluate aspirin responsiveness. Patients with Ara in the upper quartile after taking aspirin were assigned to the aspirin hyporesponsive group (Ara-Q4).

Results

A total of 292 elderly patients were included. The median value of Ara after taking aspirin was 5.87% (interquartile range 3.86–10.04%). Compared with the aspirin non-hyporesponsive group (Ara-Q1-3, Ara ≤10.04%, n=220), the level of uric acid (UA) (341.30 μmol/L vs. 299.10 μmol/L, p=0.027) and the ratios of β-blockers (9.72% vs. 2.27%, p=0.015) and diuretics (6.94% vs. 1.36%, p=0.036) were higher in the aspirin hyporesponsive group (Ara-Q4, Ara >10.04%, n=72). After multivariate adjustment, the results demonstrated baseline Ara (odds ratio [OR]: 1.030, 95% confidence interval [CI]: 1.004–1.056, p=0.021), UA level (OR: 1.003, 95% CI: 1.000–1.006, p=0.038), and β-blockers use (OR: 5.487, 95% CI: 1.515–19.870, p=0.010) were independently and positively associated with aspirin hyporesponsiveness.

Conclusions

This study found that baseline Ara, UA level, and β-blockers use were independently and positively associated with aspirin hyporesponsiveness in elderly Chinese patients, which needs to be validated in large-scale studies.

The Relationship Between Aspirin Resistance and Carotid Imaging in Young Patients With ST-Segment Elevated Myocardial Infarction: A Cross-Sectional Study

The presence of carotid atherosclerosis accompanied by coronary artery disease is associated with poor prognosis. A subset of patients who take aspirin continue to have recurrent cardiovascular events, which may be due to aspirin resistance (AR). Also, carotid plaques may cause turbulent flow which in turn may lead to platelet activation and poor antiplatelet response. In our study, we aimed to show the prevalence of AR and its relationship between high-risk carotid images in young patients with ST-segment elevated myocardial infarction (STEMI). In our study, we included 112 patients younger than 45 years with STEMI. Aspirin response test was evaluated 1 hour after aspirin intake using multiplate platelet function analyzer, and carotid ultrasonography has been performed to determine carotid intima–media thickness (CIMT) and the presence of carotid plaque. We identified 30.3% AR in young patients with STEMI. Carotid intima–media thickness (P = .002), carotid plaque (P = .012), and high-risk carotid image (P = .015) values are significantly high in patients who have AR. Independent of other risk factors, the presence of carotid plaque and being in the high-risk carotid group were associated with 3.7 times and 3.2 times increased odds for AR, respectively. In young patients with STEMI, physicians should be careful about AR, especially in patients who have carotid plaque and thicker CIMT.

Predictors of high on-aspirin platelet reactivity in elderly patients with coronary artery disease

Objectives

Previous studies have illustrated the link between high on-aspirin platelet reactivity (HAPR) with increasing thrombotic risks. The aim of our study was to investigate relative risk factors of HAPR in elderly patients with coronary artery disease.

Methods

Elderly, hospitalized coronary artery disease patients on regular aspirin treatment were enrolled from January 2014 to September 2016. Medical records of each patient were collected, including demographic information, cardiovascular risk factors, concomitant drugs and routine biological parameters. Arachidonic acid (AA, 0.5 mg/mL) and adenosine diphosphate (ADP, 5 µmol/L) induced platelet aggregation were measured via light transmission assay (LTA) to evaluate antiplatelet responses, referred as LTA–AA and LTA–ADP.

Results

A total of 275 elderly patients were included, with mean age of 77.2±8.1 years, and males accounted for 81.8%. HAPR was defined as LTA–AA in the upper quartile of the enrolled population. HAPR patients tended to have lower renal function (P=0.052). Higher serum uric acid (SUA) level, as well as lower platelet count, hemoglobin and hematocrit were observed in HAPR patients, with a higher proportion of diuretics use (P<0.05). Multivariate analysis revealed that SUA (OR: 1.004, 95% CI: 1.000–1.007, P=0.048), platelet count (OR: 0.994, 95% CI: 0.989–1.000, P=0.045), hematocrit (OR: 0.921, 95% CI: 0.864–0.981, P=0.011) and concomitant P2Y12 receptor inhibitors use (OR: 1.965, 95% CI: 1.075–3.592, P=0.028) were correlated with HAPR. Spearman’s correlation analysis demonstrated an inverse association of LTA–AA with hematocrit (r=−0.234, P<0.001), hemoglobin (r=−0.209, P<0.001) and estimated glomerular filtration rate (r=−0.132, P=0.031).

Conclusion

SUA, platelet count, hematocrit and P2Y12 receptor inhibitors use were independently correlated with HAPR. These parameters might provide novel therapeutic targets for optimizing antiplatelet therapy.

Establishing a predictive model for aspirin resistance in elderly Chinese patients with chronic cardiovascular disease

Background

Resistance to anti-platelet therapy is detrimental to patients. Our aim was to establish a predictive model for aspirin resistance to identify high-risk patients and to propose appropriate intervention.

Methods

Elderly patients (n = 1130) with stable chronic coronary heart disease who were taking aspirin (75 mg) for > 2 months were included. Details of their basic characteristics, laboratory test results, and medications were collected. Logistic regression analysis was performed to establish a predictive model for aspirin resistance. Risk score was finally established according to coefficient B and type of variables in logistic regression. The Hosmer–Lemeshow (HL) test and receiver operating characteristic curves were performed to respectively test the calibration and discrimination of the model.

Results

Seven risk factors were included in our risk score. They were serum creatinine (> 110 μmol/L, score of 1); fasting blood glucose (> 7.0 mmol/L, score of 1); hyperlipidemia (score of 1); number of coronary arteries (2 branches, score of 2; ≥ 3 branches, score of 4); body mass index (20–25 kg/m², score of 2; > 25 kg/m², score of 4); percutaneous coronary intervention (score of 2); and smoking (score of 3). The HL test showed P ≥ 0.05 and area under the receiver operating characteristic curve ≥ 0.70.

Conclusions

We explored and quantified the risk factors for aspirin resistance. Our predictive model showed good calibration and discriminative power and therefore a good foundation for the further study of patients undergoing anti-platelet therapy.

Variation in dietary salt intake induces coordinated dynamics of monocyte subsets and monocyte-platelet aggregates in humans: implications in end organ inflammation

BACKGROUND

Monocyte activation and tissue infiltration are quantitatively associated with high-salt intake induced target organ inflammation. We hypothesized that high-salt challenge would induce the expansion of CD14++CD16+ monocytes, one of the three monocyte subsets with a pro-inflammatory phenotype, that is associated with target organ inflammation in humans.

METHODOLOGY/PRINCIPAL FINDINGS

A dietary intervention study was performed in 20 healthy volunteers, starting with a 3-day usual diet and followed with a 7-day high-salt diet (≥15 g NaCl/day), and a 7-day low-salt diet (≤5 g NaCl/day). The amounts of three monocyte subsets ("classical" CD14++CD16-, "intermediate" CD14++CD16+ and "non-classical" CD14+CD16++) and their associations with monocyte-platelet aggregates (MPAs) were measured by flow cytometry. Blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) was used to evaluate renal hypoxia. Switching to a high-salt diet resulted in CD14++ monocyte activation and a rapid expansion of CD14++CD16+ subset and MPAs, with a reciprocal decrease in the percentages of CD14++CD16- and CD14+CD16++ subsets. In vitro study using purified CD14++ monocytes revealed that elevation in extracellular [Na(+)] could lead to CD14++CD16+ expansion via a ROS dependent manner. In addition, high-salt intake was associated with progressive hypoxia in the renal medulla (increased R2* signal) and enhanced urinary monocyte chemoattractant protein-1 (MCP-1) excretion, indicating a temporal and spatial correlation between CD14++CD16+ subset and renal inflammation. The above changes could be completely reversed by a low-salt diet, whereas blood pressure levels remained unchanged during dietary intervention.

CONCLUSIONS/SIGNIFICANCE

The present work demonstrates that short-term increases in dietary salt intake could induce the expansion of CD14++CD16+ monocytes, as well as an elevation of MPAs, which might be the underlying cellular basis of high-salt induced end organ inflammation and potential thromboembolic risk. In addition, this process seems largely unrelated to changes in blood pressure levels. This finding provides novel links between dietary salt intake, innate immunity and end organ inflammation.