Platelets function assessment in patients qualified for cardiac surgery - clinical problems and a newer diagnostic possibilities

Assessment of Platelet Reactivity and Inflammatory Markers in Coronary Artery Bypass Graft Patients Treated with Acetylsalicylic Acid with Flavonoid Supplementation

The recommended pharmacological therapy for patients with coronary artery disease (CAD) treated by coronary artery bypass grafting (CABG) is acetylsalicylic acid (ASA). To improve the antiplatelet effect, supplementation with flavonoids is also recommended. The aim of this study was to estimate anti-aggregation properties of diosmin, in combination with ASA, pre- and postoperatively and assess the relationship of this therapy with inflammatory processes in CAD patients undergoing CABG. The study patients (n = 26) took diosmin (1000 mg/day); the control patients (n = 27) took a placebo. The therapeutic period for taking diosmin was from at least 30 days before to 30 days after CABG. All patients also took 75 mg/day ASA. Platelet aggregation and IL-6, CRP, and fibrinogen concentrations were determined before and 30 days after surgery. Results showed that diosmin did not enhance the anti-aggregation effect of ASA at any assessment time. However, there was a stronger anti-aggregation effect 30 days after surgery that was diosmin independent and was associated with acute-phase markers in the postoperative period. Increased levels of inflammatory markers in the late phase of the postoperative period may provide an unfavorable prognostic factor in long-term follow-up, which should prompt the use of stronger antiplatelet therapy in patients after CABG.

Perioperative care in cardiac surgery

As mortality is now low for many cardiac surgical procedures, there has been an increasing focus on patient centered outcomes such as recovery and quality of life. The Enhanced Recovery After Surgery (ERAS) cardiac society recently published the first set of guidelines for cardiac surgery which will be useful as a starting point to help translate this philosophy for the benefit of those undergoing cardiac surgery. At the same time there are many advances in other areas such as mechanical circulation, diagnostics and quality metrics. We intend here to present a balanced and evidenced based review of selected aspects of current practice, encompassing both UK and international perioperative care with a focus on recent advances. For the convenience of the reader we will adopt the conventional perioperative preoperative, intraoperative and postoperative phases of care. The focus of cardiac surgical practice needs to evolve from mortality to recovery. Those specialists who work in cardiac anaesthesia and critical care are well placed to contribute to these changes. Accompanying this work is the development of technologies to improve recognition of and intervention to prevent early organ dysfunction. Measuring, benchmarking and publishing quality outcomes from cardiac surgical centres is likely to improve services and benefit our patients.

Implementation of Perioperative Point-of-Care Platelet Function Analyses Reduces Transfusion Requirements in Cardiac Surgery: A Retrospective Cohort Study

Background Platelet dysfunction is a common cause of bleeding, perioperative blood transfusion, and surgical re-exploration in cardiac surgical patients. We evaluated the effect of incorporating a platelet function analyzer utilizing impedance aggregometry (Multiplate, Roche, Munich, Germany) into our local transfusion algorithm on the rate of platelet transfusion and postoperative blood loss in patients undergoing coronary artery bypass grafting (CABG) surgery.

Methods Data were collected on patients undergoing CABG surgery from January 2015 to April 2017. Patients who underwent surgery before and after introduction of this algorithm were classified into prealgorithm and postalgorithm groups, respectively. The primary outcome was the rate of platelet transfusion before and after implementation of the Multiplate-based transfusion algorithm. Secondary outcomes included transfusion rate of packed red blood cells, postoperative blood loss at 12 and 24 hours, length of stay in the intensive care unit, and the hospital and mortality.

Results A total of 726 patients were included in this analysis with 360 and 366 patients in the pre- and postalgorithm groups, respectively. Transfusion rates of platelets (p = 0.01) and packed red blood cells (p = 0.0004) were significantly lower following introduction of the algorithm in patients (n = 257) who had insufficient time to withhold antiplatelet agents. Receiver operating characteristic curves defined optimal cutoff points of arachidonic acid and adenosine diphosphate assays on the Multiplate to predict future platelet transfusion were 23AU and 43AU, respectively.

Conclusions The introduction of a Multiplate-based platelet transfusion algorithm showed a statistically significant reduction in the administration of platelets to patients undergoing urgent CABG surgery.