Platelet Transfusion in Cardiac Surgery: An Entropy-Balanced, Weighted, Multicenter Analysis

BACKGROUND

Platelet transfusion is common in cardiac surgery, but some studies have suggested an association with harm. Accordingly, we investigated the association of perioperative platelet transfusion with morbidity and mortality.

METHODS

We conducted a retrospective analysis of prospectively collected data from the Australian Society of Cardiac and Thoracic Surgeons National Cardiac Surgery Database. We included consecutive adults from 2005 to 2018 across 40 centers. We used inverse probability of treatment weighting via entropy balancing to investigate the association of perioperative platelet transfusion with our 2 primary outcomes, operative mortality (composite of both 30-day and in-hospital mortality) and 90-day mortality, as well as multiple other clinically relevant secondary outcomes.

RESULTS

Among 119,132 eligible patients, 25,373 received perioperative platelets and 93,759 were considered controls. After entropy balancing, platelet transfusion was associated with reduced operative mortality (odds ratio [OR], 0.63; 99% confidence interval [CI], 0.47-0.84; P < .0001) and 90-day mortality (OR, 0.66; 99% CI, 0.51-0.85; P < .0001). Moreover, it was associated with reduced odds of deep sternal wound infection (OR, 0.57; 99% CI, 0.36-0.89; P = .0012), acute kidney injury (OR, 0.84; 99% CI, 0.71-0.99; P = .0055), and postoperative renal replacement therapy (OR, 0.71; 99% CI, 0.54-0.93; P = .0013). These positive associations were observed despite an association with increased odds of return to theatre for bleeding (OR, 1.55; 99% CI, 1.16-2.09; P < .0001), pneumonia (OR, 1.26; 99% CI, 1.11-1.44; P < .0001), intubation for longer than 24 hours postoperatively (OR, 1.13; 99% CI, 1.03-1.24; P = .0012), inotrope use for >4 hours postoperatively (OR, 1.14; 99% CI, 1.11-1.17; P < .0001), readmission to hospital within 30 days of surgery (OR, 1.22; 99% CI, 1.11-1.34; P < .0001), as well as increased drain tube output (adjusted mean difference, 89.2 mL; 99% CI, 77.0 mL-101.4 mL; P < .0001).

CONCLUSIONS

In cardiac surgery patients, perioperative platelet transfusion was associated with reduced operative and 90-day mortality. Until randomized controlled trials either confirm or refute these findings, platelet transfusion should not be deliberately avoided when considering odds of death.

Platelet Transfusion After Cardiac Surgery

OBJECTIVES

To investigate the independent association of platelet transfusion with hospital mortality and key relevant clinical outcomes in cardiac surgery.

DESIGN

A single-center, propensity score-matched, retrospective, cohort study.

SETTING

At an American tertiary teaching hospital data from the Medical Information Mart for Intensive Care III and IV databases from 2001 to 2019.

PARTICIPANTS

Consecutive adults undergoing coronary artery bypass graft and/or cardiac valvular surgery.

INTERVENTIONS

Platelet transfusion during perioperative intensive care unit (ICU) admission.

MEASUREMENTS AND MAIN RESULTS

Overall, 12,043 adults met the study inclusion criteria. Of these, 1,621 (13.5%) received apheresis-leukoreduced platelets, with a median of 1.19 units per recipient (IQR: 0.93-1.19) at a median of 1.78 hours (IQR: 0.75-4.25) after ICU admission. The platelet count was measured in 1,176 patients (72.5%) before transfusion, with a median count of 120 × 10⁹/L (IQR: 89.0-157.0), and only 53 (3.3%) had platelet counts below 50 × 10⁹/L. After propensity matching of 1,046 platelet recipients with 1,046 controls, perioperative platelet transfusion carried no association with in-hospital mortality (odds ratio [OR]: 1.28; 99% CI: 0.49-3.35; p = 0.4980). However, it was associated with a pattern of decreased odds of suspected infection (eg, respiratory infection, urinary tract infection, septicaemia, or other; OR: 0.70; 99% CI: 0.50-0.97; p = 0.0050), days in the hospital (adjusted mean difference [AMD]: 0.86; 99% CI: -0.27 to 1.98; p = 0.048), or days in intensive care (AMD 0.83; 99% CI: -0.15 to 1.82; p = 0.0290).

CONCLUSIONS

Platelet transfusion was not associated with hospital mortality, but it was associated with decreased odds of suspected infection and with shorter ICU and hospital stays.

The Predictive Role of Intraoperative Blood Transfusion Components in the Prognosis of Heart Transplantation

Purpose

To evaluate the influence of transfusion amount of blood components on the prognosis of patients after heart transplantation (HTx).

Methods

From 1 January 2015 to 31 December 2020, 568 patients underwent HTx in our institute. A total of 416 recipients with complete datasets were enrolled in the study for final statistical analysis according to the inclusion criteria. The optimal cut-off values for intraoperative transfusion of red blood cell (RBC), platelet, and plasma were determined with receiver operating curve analysis. Univariate and multivariate Cox regression analyses were applied to compare baseline data of patients divided by the transfusion amounts of RBC, platelet, and plasma. Propensity score matching was used to enable the direct comparison of outcomes.

Results

The Kaplan–Meier analysis revealed that transfusion amounts of RBC and plasma were independently associated with overall mortality, increased intensive care unit stay time, and major adverse events after transplantation. The multivariate Cox regression analysis suggested that neurological complications (p = 0.001), liver damage (p = 0.011), and respiratory complications (p = 0.044) were independent risk factors for overall mortality after HTx. Combining indicators presented a good predicting effect of peritransplant period mortality (AUC = 0.718).

Conclusion

The mortality of HTx was significantly related to the high-amount transfusion of RBC and plasma. Comprehensively considering the components of blood transfusion obtained better predictive results of peritransplant period survival than solely considering a single component.

Early Chest Re-Exploration for Excessive Bleeding in Post Cardiac Surgery Patients: Does It Matter?

Introduction Re-explorations after open-heart surgery are often required if the patient is bleeding or shows features of cardiovascular instability and does not improve with conservative measures. Our study aims to determine whether timely re-exploration of patients who are bleeding has an impact on the morbidity and mortality of the patients. Methods A retrospective analysis of 75 patients that underwent open-heart surgery and subsequently underwent chest re-exploration for excessive bleeding between March 2018 and March 2020. Patients who were reopened post-op for indications other than excessive bleeding were excluded. Results A total number of cases were 700, out of which 75 (9.3%) patients were reopened, as compared to the literature, which shows worldwide 2-11% being reopened. Post-operative drain output was 1000ml to 1500ml in 47 (62.7%) and more than 1500ml in 28 (37.3%) patients before they were reopened. In 67 (89.3%) patients, three to five units of blood were transfused, and in eight (10.7%) patients, more than five units of blood were transfused. We believe our mortality in the reopened patients was low, because of timely intervention and early re-exploration, and is probably the reason why our figures land in a higher range (2-11%) of reopened cases (9.3%). Reopening time was less than five hours in 49 (65.3%) patients and less than 10 hours in 26 (34.7%) patients in our study. We tried to minimize the loss of blood and re-explored the patients before they lose excessive blood, the average time for reopening in our study was less than 10 hours. The average intensive care unit (ICU) stay was 4.2 days (range three to six days). Wound infections were reported in one of three patients. There was no mortality in these patients. Surgical site of bleeding was identified in 54 (72%) patients and no particular site was found in 21 (28%) patients. Suggesting that it is common to have a surgical bleeder than coagulopathy induced bleeding in post-cardiac surgery patients Conclusions We believe our low mortality (0%) is due to early reopening in patients who are bleeding excessively after cardiac surgery.

Major Bleeding after Surgical Revascularization with Dual Antiplatelet Therapy

OBJECTIVE

Patients with acute coronary syndrome are treated with dual antiplatelet therapy containing acetylsalicylic acid (ASA) and P2Y12 antagonists. In case of urgent coronary artery bypass grafting this might be associated with increasing risks of bleeding complications.

METHODS

Data from 1200 consecutive urgent operations between 2010 and 2018 were obtained from our institutional patient database. For this study off-pump surgery was excluded. The primary composite end point major bleeding consisted of at least one end point: transfusion ≥ 5 packed red blood cells within 24 hours, rethoracotomy due to bleeding, chest tube output >2000 mL within 24 hours. Demographic data, peri-, and postoperative variables and outcomes were compared between patients treated with mono antiplatelet therapy, ASA + clopidogrel (ASA-C) +ticagrelor (ASA-T) or +prasugrel (ASA-P) < 72 hours before surgery. Furthermore, we compared patients with dual antiplatelet therapy with ASA monotherapy.

RESULTS

From 1,086 patients, 475 (44%) received dual antiplatelet therapy. Three-hundred seventy-two received ASA-C (77.7%), 72 ASA-T (15%), and 31 ASA-P (6.5%). Major bleeding (44 vs. 23%, p < 0.0001) was more frequently in patients receiving dual therapy with higher rates of massive drainage loss within 24 hours (23 vs. 11%, p < 0.0001) of mass transfusion (34 vs. 16%, p < 0.0001) and rethoracotomy (10 vs. 5%, p = 0.002) when compared with ASA. In this analysis, ASA-T and ASA-P were not associated with higher bleeding complications compared with ASA-C.

CONCLUSION

Dual antiplatelet therapy is associated with higher rates of major bleeding. Further studies should examine the difference in the prevalence of major bleeding complications in the different dual antiplatelet therapy regimes in patients requiring urgent surgery.

To jump or not to jump? A multicentre propensity-matched study of sequential vein grafting of the heart†

OBJECTIVES

In this propensity-matched study we investigated the outcome after grafting with either a single vein or a sequential vein grafting strategy. Outcomes were primarily risk of reintervention and death in the short, intermediate and long term (10 years).

MATERIALS

In the period from 2000 to 2016, data from 24 742 patients undergoing coronary artery bypass grafting were extracted from the Western Denmark Heart Registry, where data are registered perioperatively. We used a propensity-matched study in which the study groups were matched on parameters primarily from the EuroSCORE. The numbers of patients in both groups after matching were 3380.

RESULTS

Single grafts resulted in significantly more postoperative bleeding and were more time-consuming. No differences were seen regarding in-hospital events such as stroke, acute myocardial infarction, dialysis or arrhythmias. After 30 days, patients in the jump graft group showed an increased rate of reintervention due to ischaemia after adjusting for confounding factors [hazard ratio (HR) 2.08, 95% confidence interval 1.01-4.34]. In addition, after adjusting for known confounders, sequential grafts were found to increase the risk of mortality at 6 months (HR 1.51, 95% confidence limits 1.07-2.11) and 5 years (HR 1.23, 95% confidence limits 1.04-1.46).

CONCLUSIONS

This propensity-matched analysis suggested, although discretely, that a jump graft as a grafting strategy is associated with a slightly increased risk of mortality and early graft failure and that a single grafting strategy to the coronary arteries should be preferred when feasible.

The design of an adaptive clinical trial to evaluate the efficacy of platelets stored at low temperature in surgical patients

BACKGROUND

Storage of platelets at 4°C compared with 22°C may increase both hemostatic activity and storage duration; however, the maximum duration of cold storage is unknown. We report the design of an innovative, prospective, randomized, Bayesian adaptive, "duration finding" clinical trial to evaluate the efficacy and maximum duration of storage of platelets at 4°C.

METHODS

Patients undergoing cardiac surgery and requiring platelet transfusions will be enrolled. Patients will be randomized to receive platelets stored at 22°C up to 5 days or platelets stored at 4°C up to 5 days, 10 days, or 15 days. Longer durations of cold storage will only be used if shorter durations at 4°C appear noninferior to standard storage, based on a four-level clinical hemostatic efficacy score with a NIM of a half level. A Bayesian linear model is used to estimate the hemostatic efficacy of platelet transfusions based on the actual duration of storage at 4°C.

RESULTS

The type I error rate, if platelets stored at 4°C are inferior, is 0.0247 with an 82% probability of early stopping for futility. With a maximum sample size of 1,500, the adaptive trial design has a power of over 90% to detect noninferiority and a high probability of correctly identifying the maximum duration of storage at 4°C that is noninferior to 22°C.

CONCLUSION

An adaptive, duration-finding trial design will generate Level I evidence and allow the determination of the maximum duration platelet storage at 4°C that is noninferior to standard storage at 22°C, with respect to hemostatic efficacy. The adaptive trial design helps to ensure that longer cold storage durations are only explored once substantial supportive data are available for the shorter duration(s) and that the trial stops early if continuation is likely to be futile.

Leukodepleted Packed Red Blood Cells Transfusion in Patients Undergoing Major Cardiovascular Surgical Procedure: Systematic Review and Meta-Analysis

Background

Leukocytes contained in the allogeneic packed red blood cell (PRBC) are the cause of certain adverse reactions associated with blood transfusion. Leukoreduction consists of eliminating leukocytes in all blood products below the established safety levels for any patient type. In this systematic review, we appraise the clinical effectiveness of allogeneic leukodepleted (LD) PRBC transfusion for preventing infections and death in patients undergoing major cardiovascular surgical procedures.

Methods

We searched randomized controlled trials (RCT), enrolling patients undergoing a major cardiovascular surgical procedure and transfused with LD-PRBC. Data were extracted, and risk of bias was assessed according to Cochrane guidelines. In addition, trial sequential analysis (TSA) was used to assess the need of conducting additional trials. Quality of the evidence was assessed using the GRADE approach.

Results

Seven studies met the eligibility criteria. Quality of the evidence was rated as moderate for both outcomes. The risk ratio for death from any cause comparing the LD-PRBC versus non-LD-PRBC group was 0.69 (CI 95% = 0.53 to 0.90; I² = 0%). The risk ratio for infection in the same comparison groups was 0.77 (CI 95% = 0.66 to 0.91; I² = 0%). TSA showed a conclusive result in this outcome.

Conclusions

We found evidence that supports the routine use of leukodepletion in patients undergoing a major cardiovascular surgical procedure requiring PRBC transfusion to prevent death and infection. In the case of infection, the evidence should be considered sufficient and conclusive and hence indicated that further trials would not be required.

Prophylactic Preprocedure Platelet Transfusion Is Associated With Increased Risk of Thrombosis and Mortality

OBJECTIVES

We evaluated thrombosis and mortality rates of hospitalized patients receiving prophylactic platelet transfusion prior to an invasive procedure.

METHODS

Patient age and underlying medical condition(s), preprocedure and postprocedure platelet counts, type of procedure, number of platelet products transfused, and any complications were recorded on every prophylactic platelet given prior to an invasive procedure.

RESULTS

A total of 376 prophylactic transfusion recipients were identified. Nineteen (5%) thrombotic events were identified and 60 (16%) deaths occurred within 30 days of the preprocedure platelet transfusion. Most deaths were due to infection, sepsis, or organ failure, and none were due to bleeding or thrombosis.

CONCLUSIONS

Preprocedure platelet transfusion is associated with an increased risk of thrombosis and 30-day mortality. Whether these findings are due to higher incidences of comorbidities and confounding or to cause and effect is not determinable from these data. This study highlights an association between prophylactic platelet transfusion and thrombosis and poor outcome, including death.

Does a Platelet Transfusion Independently Affect Bleeding and Adverse Outcomes in Cardiac Surgery?

Background

Conflicting results have been reported concerning the effect of platelet transfusion on several outcomes. The aim of this study was to assess the independent effect of a single early intraoperative platelet transfusion on bleeding and adverse outcomes in cardiac surgery patients.

Methods

For this observational study, 23,860 cardiac surgery patients were analyzed. Patients who received one early (shortly after cardiopulmonary bypass while still in the operating room) platelet transfusion, and no other transfusions, were defined as the intervention group. By matching the intervention group 1:3 to patients who received no early transfusion with most comparable propensity scores, the reference group was identified.

Results

The intervention group comprised 169 patients and the reference group 507. No difference between the groups was observed concerning reinterventions, thromboembolic complications, infections, organ failure, and mortality. However, patients in the intervention group experienced less blood loss and required vasoactive medication 139 of 169 (82%) versus 370 of 507 (74%; odds ratio, 1.65; 95% CI, 1.05 to 2.58), prolonged mechanical ventilation 92 of 169 (54%) versus 226 of 507 (45%; odds ratio, 1.47; 94% CI, 1.03 to 2.11), prolonged intensive care 95 of 169 (56%) versus 240 of 507 (46%; odds ratio, 1.49; 95% CI, 1.04 to 2.12), erythrocytes 75 of 169 (44%) versus 145 of 507 (34%; odds ratio, 1.55; 95% CI, 1.08 to 2.23), plasma 29 of 169 (17%) versus 23 of 507 (7.3%; odds ratio, 2.63; 95% CI, 1.50–4.63), and platelets 72 of 169 (43%) versus 25 of 507 (4.3%; odds ratio, 16.4; 95% CI, 9.3–28.9) more often compared to the reference group.

Conclusions

In this retrospective analysis, cardiac surgery patients receiving platelet transfusion in the operating room experienced less blood loss and more often required vasoactive medication, prolonged ventilation, prolonged intensive care, and blood products postoperatively. However, early platelet transfusion was not associated with reinterventions, thromboembolic complications, infections, organ failure, or mortality.

Routine transfusion of platelet concentrates effectively reduces reoperation rate for bleeding and pericardial effusion after elective operations for ascending aortic aneurysm

Patients with ascending aortic aneurysm undergoing complex surgical procedures are at increased risk of early postoperative excessive blood loss. The aim of this study was to analyze safety and efficacy of routine transfusions of platelet (PLT) concentrates in reduction of hemorrhagic postoperative complications. The study involved 396 consecutive patients (289 males and 107 females) with the mean age of 55.9 ± 13.6 years who underwent elective operations for aortic aneurysms. They were divided retrospectively into two groups, without (group A; n = 123) or with the routine use of PLTs (group B; n = 273). PLTs were transfused intraoperatively just after completion of cardiopulmonary bypass. Twelve patients in group A (9.8%) and 10 (3.7%) in group B required re-thoracotomy due to hemorrhage (p = 0.027). Routine transfusions of PLT concentrates reduced postoperative incidence of excessive pericardial effusion from 24.1% in group A to 2.1% in group B (p = 0.002). In a consequence, significantly less units (p < 0.0001) of red blood concentrates and fresh frozen plasma were transfused in group B than in group A. The rates of other adverse events in the early postoperative period did not differ between groups. Patients with pericardial effusion required 6.3 ± 2.7 additional days of hospitalization due to surgical re-intervention. Neither blood transfusion-related infections nor adverse reactions were noted. In conclusion, routine intraoperative transfusions of PLT concentrates in patients with ascending aortic aneurysms significantly reduced a need for re-intervention due to both early bleeding and late cardiac tamponade.