Relation of Hypoalbuminemia to Response to Aspirin in Patients With Stable Coronary Artery Disease

Albumin Infusion and Blood Loss After Cardiac Surgery

BACKGROUND

In the recent ALBICS (ALBumin In Cardiac Surgery) trial, 4% albumin used for cardiopulmonary bypass priming and volume replacement increased perioperative bleeding compared with Ringer acetate. In the present exploratory study, albumin-related bleeding was further characterized.

METHODS

Ringer acetate and 4% albumin were compared in a randomized, double-blinded fashion in 1386 on-pump adult cardiac surgery patients. The study end points for bleeding were the Universal Definition of Perioperative Bleeding (UDPB) class and its components.

RESULTS

The UDPB bleeding grades were higher in the albumin group than the Ringer group: "insignificant" (albumin vs Ringer: 47.5% vs 62.9%), "mild" (12.7% vs 8.9%), "moderate" (28.7% vs 24.4%), "severe" (10.2% vs 3.2%), and "massive" (0.9% vs. 0.6%; P < .001). Patients in the albumin group received red blood cells (45.2% vs 31.5%; odds ratio [OR], 1.80; 95% CI, 1.44-2.24; P < .001), platelets (33.3% vs 21.8%; OR, 1.79; 95% CI, 1.41-2.28; P < .001), and fibrinogen (5.6% vs 2.6%; OR, 2.24; 95% CI, 1.27-3.95; P < .05), and underwent resternotomy (5.3% vs 1.9%; OR, 2.95; 95% CI, 1.55-5.60, P < .001) more often than patients in the Ringer group. The strongest predictors of bleeding were albumin group allocation (OR, 2.18; 95% CI, 1.74-2.74) and complex (OR, 2.61; 95% CI, 2.02-3.37) and urgent surgery (OR, 1.63; 95% CI, 1.26-2.13). In interaction analysis, the effect of albumin on the risk of bleeding was stronger in patients on preoperative acetylsalicylic acid.

CONCLUSIONS

Perioperative administration of albumin, compared with Ringer's acetate, resulted in increased blood loss and higher UDBP class. The magnitude of this effect was similar to the complexity and urgency of the surgery.

Preoperative hypoalbuminemia in patients undergoing cardiac surgery: a meta-analysis

The preoperative serum albumin level has been shown to be associated with adverse postoperative complications, meaning that hypoalbuminemia may also be a risk factor. We performed a meta-analysis to evaluate the association of serum albumin levels with survival and complication rates after cardiac surgery. Relevant articles were identified through seven databases. Twenty studies with 22553 patients (hypoalbuminemia group, n = 9903; normal group, n = 12650) who underwent cardiac surgery met the inclusion criteria after screening. The primary outcomes were that hypoalbuminemia was significantly correlated with serious long-term all-cause mortality (hazard ratio [HR]: 1.95 [1.54-2.48]; P < 0.00001) and increased mortality (risk ratio [RR] = 1.91 [1.61-2.27], P < 0.00001). Hypoalbuminemic patients with cardiopathy were more likely to suffer postoperative complications (bleeding, infections, renal injury, and others) than those whose serum albumin levels were normal. Furthermore, hypoalbuminemia increased the time in the intensive-care unit (ICU) (mean difference [MD] = 1.18 [0.49-1.87], P = 0.0008), length of hospital stay (LOS) (MD = 3.34, 95% CI: 1.88-4.80, P < 0.00001), and cardiopulmonary bypass time (CPB) (MD = 12.40 [1.13-23.66], P = 0.03). Hypoalbuminemia in patients undergoing cardiac surgery appears to have a poor all-cause mortality or increased risk of complications. Adjusted perioperative serum albumin levels and treatment strategies for this high-risk population have the potential to improve the survival.

Impaired Clinical Efficacy of Aspirin in Hypoalbuminemic Patients With Diabetes Mellitus

Objective: To investigate the impact of albumin levels on the aspirin efficacy, since aspirin inhibits platelet aggregation (PA) by cyclooxygenase one irreversible acetylation that is less effective in patients with type 2 diabetes mellitus (T2DM).

Patients and Methods: A total of 612 aspirin (100 mg/day)-treated T2DM patients were followed-up for 54.4 ± 7.3 months. The primary endpoint, a composite of cardiovascular events (CVEs) including CV death, myocardial infarction, ischemic stroke and coronary revascularization, was analysed according to baseline values of serum albumin (≥ or < 3.5 g/dL). Serum thromboxane (Tx)B₂ was also measured.

Results: 250 (40.8%) patients had serum albumin < 3.5 g/dL; these patients were overweight and had higher values of fibrinogen (p = 0.009), high sensitivity C-reactive protein (p = 0.001) and fasting plasma glucose (p < 0.0001) compared to those with albumin ≥ 3.5 g/dL. During follow-up, 86 CVEs were recorded, 49 and 37 in patients with serum albumin < or ≥3.5 g/dL, respectively (p = 0.001). At multivariable Cox regression analysis, serum albumin < 3.5 g/dL (hazard ratio [HR] 1.887, 95% confidence interval [CI] 1.136–3.135, p = 0.014), age (HR 1.552 for every 10 years, 95%CI 1.157–2.081, p = 0.003), fasting plasma glucose (HR 1.063, 95%CI 1.022–1.105, p = 0.002) and beta-blocker use (HR 0.440, 95%CI 0.270–0.717, p = 0.001) were associated to CVEs. Serum TxB₂ levels (n = 377) were 0.32 ± 0.12 and 0.24 ± 0.12 ng/ml in patients with albumin < or ≥ 3.5 g/dL, respectively (p < 0.001).

Conclusion: In T2DM patients, the efficacy of aspirin varies according to albumin levels. Hypoalbuminemia associated with impaired TxB₂ inhibition and an increased risk of long-term CVEs.

The Association between Multi-Vessel Coronary Artery Disease and High On-Aspirin Platelet Reactivity

BACKGROUND

Multi-vessel coronary artery disease (MV-CAD) is correlated with worse clinical outcomes compared with single-vessel CAD (SV-CAD). The aim of this study was to evaluate the association between MV-CAD and high on-aspirin platelet reactivity (HAPR) in patients with stable CAD treated with aspirin.

METHODS

The current study is an analysis of prospectively enrolled randomly selected patients with known stable CAD, who were taking aspirin (75-100 mg qd) regularly for at least one month, and had undergone coronary angiography at least 3 months prior to the enrollment to the study.

EXCLUSION CRITERIA

acute coronary syndrome at the time of platelet function testing, active malignancy, acute infection, active inflammatory/rheumatic disease, major surgery in the past 6 months, chronic liver failure, treatment with oral anticoagulation, non-adherence with Aspirin and thrombocytopenia (<100 K/micl). Blood was drawn from the participants and sent for platelet function testing (VerifyNow, Instrumentation Laboratory Company, Bedford, Massachusetts, United States). MV-CAD was defined as >50% stenosis in ≥2 separate major coronary territories per coronary angiography. HAPR was defined as aspirin reaction units (ARU) >550.

RESULTS

Overall, 507 patients were analyzed; age 66.7 ± 11.2, 17.9% women, 223 (44%) had MV-CAD. The rate of HAPR was significantly higher among patients with MV-CAD vs. SV-CAD (14.8% vs. 3.5%, p < 0.001, respectively). Furthermore, a "dose response"-like association was found between the number of stenotic coronary arteries and the rate of HAPR (3.5%, 13.5 and 17.3% for SV-CAD, 2-vessel and 3-vessel disease, respectively). In a multivariate analysis adjusted for potential confounders, MV-CAD was found to be a strong independent predictor of HAPR [OR = 1.8 (95%CI: 1.05-4.7), p = 0.014].

CONCLUSIONS

A significant association between MV-CAD and HAPR was found. Additional studies designed to investigate the mechanisms of HAPR and different therapeutic options for this subset of patients are warranted.

Serum albumin and cardiovascular disease: State-of-the-art review

Cardiovascular disease is the leading cause of death worldwide. Conceptually, endothelial dysfunction, inflammatory conditions and oxidative stress are at the forefront of the onset and development of most cardiovascular diseases, particularly coronary artery disease and heart failure. Serum albumin has many physiological properties, including in particular antioxidant, anti-inflammatory, anticoagulant and anti-platelet aggregation activity. It also plays an essential role in the exchange of fluids across the capillary membrane. Hypoalbuminemia is a powerful prognostic marker in the general population as well as in many disease states. In the more specific context of cardiovascular disease, low serum albumin is independently associated with the development of various deleterious conditions such as coronary artery disease, heart failure, atrial fibrillation, stroke and venous thromboembolism. Low serum albumin has also emerged as a potent prognostic parameter in patients with cardiovascular disease regardless of usual prognostic markers. Remarkably, its potent prognostic value persists after adjusting for causative confounders such as malnutrition and inflammation. This prognostic value probably refers primarily to the syndrome of malnutrition-inflammation and the severity of comorbidities. Nevertheless, several recent meta-analyses strongly support the hypothesis that hypoalbuminemia may act as an unrecognized, potentially modifiable risk factor contributing to the emergence and progression of cardiovascular disease, primarily by exacerbating oxidative stress, inflammation and platelet aggregation, and by favouring peripheral congestion and pulmonary edema. Currently, it is unknown whether prevention and correction of low serum albumin offers a benefit to patients with or at risk for cardiovascular disease, and further studies are critically needed in this setting.