Hematologic parameters, atherosclerotic progression, and prognosis in patients with previous coronary artery bypass grafting (from the Post CABG Trial)

Effects of Preoperative WBC Count on Post-CABG Surgery Clinical Outcome

OBJECTIVE

White blood cells (WBCs) play a major role in inflammation, with effects on the vascular wall, the microvascular blood flow, and endothelial cells and endothelial function. Previous studies have shown that a high WBC count may increase the risk of cardiovascular complication rate and mortality after coronary artery bypass graft (CABG) surgery. The aim of the study was to evaluate the association between preoperative WBC count and the post-CABG clinical outcome.

METHODS

A retrospective study that was based on 239 patients who underwent CABG surgery in our medical center. Statistical analysis estimated the effect of WBC count in postoperative clinical outcomes, including atrial fibrillation, length of stay, readmission rate, and death.

RESULTS

The preoperative WBC count was associated with longer hospitalization length (B = 0.392, P < 0.01). A preoperative WBC count >8150/μL predicted a longer stay (Z = 2.090, P = 0.03). A low lymphocyte count was associated with atrial fibrillation (B = -0.543, P = 0.03). Female patients were older (Z = 2.920, P < 0.01), had impaired renal function (Z = -3.340, P < 0.01), and had a higher rate of postoperative atrial fibrillation (df 2 = 3.780, P = 0.05) and readmission (df 2 = 5.320, P = 0.02).

CONCLUSIONS

Preoperative WBC count may have an effect on the postoperative clinical outcome in patients undergoing CABG. Surgeons should pay more attention to patients' WBC count and sex and plan surgery and postoperative management accordingly.

HMG CoA reductase inhibitors (statins) for preventing acute kidney injury after surgical procedures requiring cardiac bypass

BACKGROUND

Acute kidney injury (AKI) is common in patients undergoing cardiac surgery among whom it is associated with poor outcomes, prolonged hospital stays and increased mortality. Statin drugs can produce more than one effect independent of their lipid lowering effect, and may improve kidney injury through inhibition of postoperative inflammatory responses.

OBJECTIVES

This review aimed to look at the evidence supporting the benefits of perioperative statins for AKI prevention in hospitalised adults after surgery who require cardiac bypass. The main objectives were to 1) determine whether use of statins was associated with preventing AKI development; 2) determine whether use of statins was associated with reductions in in-hospital mortality; 3) determine whether use of statins was associated with reduced need for RRT; and 4) determine any adverse effects associated with the use of statins.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 13 January 2015 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared administration of statin therapy with placebo or standard clinical care in adult patients undergoing surgery requiring cardiopulmonary bypass and reporting AKI, serum creatinine (SCr) or need for renal replacement therapy (RRT) as an outcome were eligible for inclusion. All forms and dosages of statins in conjunction with any duration of pre-operative therapy were considered for inclusion in this review.

DATA COLLECTION AND ANALYSIS

All authors extracted data independently and assessments were cross-checked by a second author. Likewise, assessment of study risk of bias was initially conducted by one author and then by a second author to ensure accuracy. Disagreements were arbitrated among authors until consensus was reached. Authors from two of the included studies provided additional data surrounding post-operative SCr as well as need for RRT. Meta-analyses were used to assess the outcomes of AKI, SCr and mortality rate. Data for the outcomes of RRT and adverse effects were not pooled. Adverse effects taken into account were those reported by the authors of included studies.

MAIN RESULTS

We included seven studies (662 participants) in this review. All except one study was assessed as being at high risk of bias. Three studies assessed atorvastatin, three assessed simvastatin and one investigated rosuvastatin. All studies collected data during the immediate perioperative period only; data collection to hospital discharge and postoperative biochemical data collection ranged from 24 hours to 7 days. Overall, pre-operative statin treatment was not associated with a reduction in postoperative AKI, need for RRT, or mortality. Only two studies (195 participants) reported postoperative SCr level. In those studies, patients allocated to receive statins had lower postoperative SCr concentrations compared with those allocated to no drug treatment/placebo (MD 21.2 µmol/L, 95% CI -31.1 to -11.1). Adverse effects were adequately reported in only one study; no difference was found between the statin group compared to placebo.

AUTHORS' CONCLUSIONS

Analysis of currently available data did not suggest that preoperative statin use is associated with decreased incidence of AKI in adults after surgery who required cardiac bypass. Although a significant reduction in SCr was seen postoperatively in people treated with statins, this result was driven by results from a single study, where SCr was considered as a secondary outcome. The results of the meta-analysis should be interpreted with caution; few studies were included in subgroup analyses, and significant differences in methodology exist among the included studies. Large high quality RCTs are required to establish the safety and efficacy of statins to prevent AKI after cardiac surgery.

Is leukocytosis a predictor for recurrence of ischemic events after coronary artery bypass graft surgery? A cohort study

Objective. Studies have shown that inflammation plays an important role in pathogenesis of coronary artery disease. The present study was designed to evaluate the role of high WBC count before CABG in predicting the risk of ischemic events after CABG. Methods and Results. This prospective study was carried out on 380 patients who underwent CABG surgery. Ninety seven patients (25.5%) had recurrent ischemic event. Mean WBC count before CABG surgery in patients with recurrent ischemic event was 7267 mic/lit ± 1863, which was significantly higher than the others, with a mean WBC count of 6721 mic/lit ± 1734 (P = 0.011). Patients with a WBC count more than 6000 mic/lit were at the highest risk for recurrent ischemic event (OR = 2.11, 95% CI = 1.18–3.44, P = 0.009). After adjustment for age, sex, family history, smoking, hyperlipidemia, Logestic Euro score, post opretive enzyme release (CK.mb), arterial graft and BMI, the relationship between the group with WBC count higher than 6000 mic/lit and recurrent of ischemic event remained significant (OR = 2.25, 95% CI = 1.2 to 4, P = 0.005). Conclusions. High WBC count before CABG surgery is an independent risk factor for ischemic events one year after the surgery.

Hematologic parameters and angiographic progression of coronary atherosclerosis

Hematologic parameters have prognostic importance in cardiovascular disease. However, the relation between atherosclerosis progression and hematologic parameters is not well defined. A total of 394 patients requiring repeat coronary angiography were included in the study. According to angiography, patients were divided into 2 groups, progressive (n = 196) and nonprogressive (n = 198) diseases. Hematologic parameters including mean platelet volume (MPV) and neutrophil/lymphocyte (N/L) ratio were measured. Glucose, creatinine, and cholesterol were significantly higher in the progressive group. Mean platelet volume count was similar in both groups. The N/L ratio was significantly higher in the progressive group (5.0 ± 5.1 vs 3.2 ± 3; P = .001). In multivariate analysis, the N/L ratio was significantly related with progression (relative risk [RR]: 2.267, 95% CI: 1.068-4.815, P = .03). Progression rate was significantly high in patients with high N/L ratio (39% vs 56%). Our results suggest that the N/L ratio is a predictor of progression of atherosclerosis.

Inflammation and thrombosis in essential thrombocythemia and polycythemia vera: different role of C-reactive protein and pentraxin 3

We tested the hypothesis that levels of pentraxin high sensitivity C-reactive protein and pentraxin 3 might be correlated with cardiovascular complications in patients with essential thrombocythemia and polycythemia vera. High sensitivity C-reactive protein and pentraxin 3 were measured in 244 consecutive essential thrombocythemia and polycythemia vera patients in whom, after a median follow up of 5.3 years (range 0-24), 68 cardiovascular events were diagnosed. The highest C-reactive protein tertile was compared with the lowest (>3 vs. <1 mg/L) and correlated with age (P=0.001), phenotype (polycythemia vera vs. essential thrombocythemia, P=0.006), cardiovascular risk factors (P=0.012) and JAK2V617F allele burden greater than 50% (P=0.003). Major thrombosis rate was higher in the highest C-reactive protein tertile (P=0.01) and lower at the highest pentraxin 3 levels (P=0.045). These associations remained significant in multivariate analyses and indicate that blood levels of high sensitivity C-reactive protein and petraxin 3 independently and in opposite ways modulate the intrinsic risk of cardiovascular events in patients with myeloproliferative disorders.