Endovascular removal of a large free-floating thrombus of the descending thoracic aorta using the AngioVac system.

Free-floating aortic mural thrombus in the minimally diseased or nonaneurysmal aorta is a rare, clinically significant source of peripheral embolism. We describe a 41-year-old woman with a history of left brachial thromboembolectomy who presented atypical chest pain. Computed tomography angiography and transesophageal echocardiography revealed a 14.0 cm × 1.4 cm mobile mass in the proximal descending thoracic aorta. The thrombus was removed through a minimally invasive catheter-based approach using the AngioVac system.

Redosing of long acting cardioplegic solutions in adult cardiac surgery: A comparative study.

INTRODUCTION: Despite promising results regarding using long-acting cardioplegia in the adult population, little data exists specifically for operations requiring prolonged aortic cross-clamp needing additional doses. In this pilot study, we evaluated the outcomes of patients undergoing surgery with prolonged cross-clamp time based on four different redosing compositions. METHODS: During the period from January 2019 until June 2022, 288 patients undergoing cardiac surgery with an expected cross-clamp time over 60 min were prospectively randomized regarding the type of the cardioplegia used: Group 1 (N = 150)- single-dose del Nido antegrade cardioplegia and Group 2 (N = 138)- single-dose Histidine-Tryptophane-Ketoglutarate (HTK) antegrade cardioplegia. In patients with ischemic time over 60 min, needing a redosing were further analyzed separately in four subgroups: (A) Cold whole blood (CWB) (4:1) (N = 95); (A1: DN-CWB; A2: HTK-CWB) and (B) St Thomas Solution (N = 92) (B1: DN-St Thomas; B2: HTK-St Thomas. Control groups were C1 (DN redosed by DN) and C2 (HTK by HTK). RESULTS: Troponin levels in A1 and B1 groups were significantly lower than in DN-control. Respiratory support time and incidence of atrial fibrillation were significantly lower in Group A1 versus DN-control. CONCLUSIONS: Long-acting cardioplegic techniques are becoming widely utilized in the adult population, with minimal data on redosing methods/compositions for prolonged cases. Due to the small patient population, further investigation is needed to delineate optimal redosing methods, but this report brings to attention the initial success of multiple strategies.

Clinical outcomes of single-dose cardioplegia in high-risk coronary bypass.

BACKGROUND: Despite the increasing popularity of single-dose cardioplegia techniques in coronary artery bypass grafting, the time window for successful reperfusion remains unclear. This study aimed to compare different cardioplegic techniques based on early and 30-day clinical outcomes via thorough monitoring. METHODS: This prospective cohort study included high-risk patients undergoing coronary artery bypass grafting and receiving 3 different types of cardioplegia between January 2017 and June 2019. Group 1 (n = 101) had a single dose of del Nido cardioplegia, group 2 (n = 92) had a single dose of histidine-tryptophane-ketoglutarate, and group 3 (n = 119) had cold blood cardioplegia. Patients were examined perioperatively by memory loop recording and auto-triggered memory loop recording for 30 days, with documentation of predefined events. RESULTS: Interleukin-6 and cardiac troponin levels in group 1 were significantly higher than those in groups 2 and 3. The incidence of predefined events as markers of inadequate myocardial protection was significantly higher group 1, with more frequent atrial fibrillation attacks and more hospital readmissions. The readmission rate was 17.6% in group 1, 9% in group 2, and 8% in group 3. CONCLUSIONS: Our data demonstrate the long-term efficacy of cardioplegic techniques, which may become more crucial in high-risk patients who genuinely have a chance to benefit from adjunct myocardial protection. Patients given del Nido cardioplegia had a significantly more prominent inflammatory response and higher troponin levels after cardiopulmonary bypass. This group had issues in the longer term with significantly more cardiac events and a higher rehospitalization rate.

Comparative Effects of Single-Dose Cardioplegic Solutions Especially in Repeated Doses During Minimally Invasive Aortic Valve Surgery.

OBJECTIVE: This study aims to compare del Nido cardioplegia (DNC) and histidine-tryptophan-ketoglutarate (HTK) cardioplegic solutions in minimally invasive aortic valve replacement (mini-AVR) surgery to discuss the safety level of myocardial protection and rationale for redosing intervals. METHODS: During the period from January 2017 to June 2019, 200 patients undergoing mini-AVR (solely or with concomitant procedures) were prospectively randomized to DNC (n = 100) andHTK (n = 100), both up to 90 minutes ischemic time. Patients with ischemic time over 90 minutes, needing a redosing, were further analyzed in 2 subgroups with DNC-R (n = 30) and HTK-R (n = 36). Sensitive biomarkers, in addition to routine biochemistry, were also documented at baseline (T1), after cessation of cardiopulmonary bypass (T2), and on the first postoperative day (T3). Transmural myocardial biopsies were sampled for staining. RESULTS: No statistical differences could be demonstrated in DNC and HTK groups with up to 90 minutes cross-clamp times in routine biochemical measurements and basic perioperative clinical outcomes. DNC-R showed significantly more arrhythmia/AV block incidence resulting in more extended intensive care unit (ICU) stay. Interleukin-6 and syndecan-1 in DNC and DNC-R groups were substantially higher at T2. Aquaporin-4 levels were significantly lower in the DNC-R group, demonstrating unsatisfactory response of cells to an excessive volume at T2. CONCLUSIONS: DNC and HTK provided acceptable myocardial protection as single-dose applications. DNC-R had significantly unbalanced levels of biomarkers, and more arrhythmia/AV block incidence resulting in more extended ICU stay. For patients who may need redosing HTK may be preferable to DNC.

Minimally Invasive Aortic Valve Replacement on Minimally Invasive Extracorporeal Circulation: Going beyond Aesthetics.

We present our multidisciplinary and multistep strategy in patients undergoing minimally invasive aortic valve replacement (mAVR) on minimally invasive extracorporeal circulation (MiECC) compared with control groups of a single strategy and conventional techniques. This cohort study included high-risk patients (Society of Thoracic Surgeons [STS] risk score >8%) undergoing aortic valve surgery under different strategies during the period from January 2017 until March 2019. Patients were matched for age, gender, body mass index, and STS score: group 1 (MiAVR) based on a minimally invasive technique with J-mini-sternotomy, rapid deployment valve (RDV), and type IV customized MiECC; group 2 (control-mAVR) consisted of minimally invasive technique with only J mini-sternotomy and RDV on a conventional extracorporeal system; group 3 (control-MiECC): full sternotomy and type IV customized MiECC; and group 4 (control): full sternotomy on a conventional extracorporeal system. The MiAVR group had significantly less duration of x-clamp time (35.4 ± 11 minutes), postoperative respiratory support (4.1 ± 1 hour), postoperative hemorrhage (250 ± 50 mL), and intensive care unit stay (1 ± .5 days) than the control-conventional (group 4) group. Seventy-six percent of patients did not receive any blood products in MiAVR (p = .025 vs. group 4). Incidence of atrial fibrillation (8%) and low cardiac output (14%) in MiAVR were significantly better than control. Critics of minimally invasive techniques sustain that potential advantages are offset by a longer cross-clamp and cardiopulmonary bypass duration, which may translate into inferior clinical outcomes. We advocate that our multidisciplinary approach supported by multiple technologies may be associated with faster recovery and superior outcomes than conventional minimally/conventional techniques.

A Cardiopulmonary Bypass Based Blood Management Strategy in Adult Cardiac Surgery.

BACKGROUND: Despite the recent introduction of a number of technical and pharmacologic blood conservation measures, bleeding and allogeneic transfusion remain persistent problems in open-heart surgical procedures. Efforts should be made to decrease or completely avoid transfusions to avoid these negative reactions. METHODS: Our coronary artery bypass grafting database was reviewed retrospectively and a total of 243 patients who underwent cardiac surgery with cardiopulmonary bypass (CPB) were studied in a 12-month period (January-December 2016) after the implementation of the new program, and compared with 275 patients of the previous 12-month period.All the staff involved in the care of the patients were educated about the risks and benefits of blood transfusions and the new transfusion guidelines in a 45-min training. We revised our guidelines for transfusions based on the STS. A transfusion log was created. Reduction in IV fluid volume was targeted. CPB circuitry was redesigned to achieve significantly less prime volume. Results: The proportion of patients transfused with red blood cells was 56% (n =154) in the control group and reduced by 26.8% in the study group (29.2%; 71 patients; P < .01). Blood transfusion rate (1.7 ± 1/3.05 ± 1 units), postoperative hemorrhage (545 ± 50/ 775 ± 55 mL), respiratory support duration (12.4 ± 7/16.8 ± 8 h) and ICU stay (2.2±1.1/ 3.5±1.2 days) were significantly better in the blood conservation group.  Conclusion: These findings, in addition to risks and side effects of blood transfusion and the rising cost of safer blood products, justify blood conservation in adult cardiac operations.

Covalent intermediate in the catalytic mechanism of the radical S-adenosyl-L-methionine methyl synthase RlmN trapped by mutagenesis.

The posttranscriptional modification of ribosomal RNA (rRNA) modulates ribosomal function and confers resistance to antibiotics targeted to the ribosome. The radical S-adenosyl-L-methionine (SAM) methyl synthases, RlmN and Cfr, both methylate A2503 within the peptidyl transferase center of prokaryotic ribosomes, yielding 2-methyl- and 8-methyl-adenosine, respectively. The C2 and C8 positions of adenosine are unusual methylation substrates due to their electrophilicity. To accomplish this reaction, RlmN and Cfr use a shared radical-mediated mechanism. In addition to the radical SAM CX(3)CX(2)C motif, both RlmN and Cfr contain two conserved cysteine residues required for in vivo function, putatively to form (cysteine 355 in RlmN) and resolve (cysteine 118 in RlmN) a covalent intermediate needed to achieve this challenging transformation. Currently, there is no direct evidence for this proposed covalent intermediate. We have further investigated the roles of these conserved cysteines in the mechanism of RlmN. Cysteine 118 mutants of RlmN are unable to resolve the covalent intermediate, either in vivo or in vitro, enabling us to isolate and characterize this intermediate. Additionally, tandem mass spectrometric analyses of mutant RlmN reveal a methylene-linked adenosine modification at cysteine 355. Employing deuterium-labeled SAM and RNA substrates in vitro has allowed us to further clarify the mechanism of formation of this intermediate. Together, these experiments provide compelling evidence for the formation of a covalent intermediate species between RlmN and its rRNA substrate and well as the roles of the conserved cysteine residues in catalysis.

Perioperative blood conservation strategies in pediatric patients undergoing open-heart surgery: impact of non-autologous blood transfusion and surface-coated extracorporeal circuits.

BACKGROUND: The aim of this study was to explore the relative clinical and biomaterial effects of blood transfusions (Tx) and novel low-prime, surface-coated circuitry on perioperative outcome in a pediatric population undergoing cardiac surgery with cardiopulmonary bypass (CPB). METHODS: Over a 12-month period, 80 patients weighing >10 kg undergoing ventricular septal defect (VSD) repair with CPB were prospectively randomized into two groups according to the type of CBP circuit used, then each randomized group was enrolled into two groups again, according to the need for transfusion (N=20): Group 1- Tx-free procedures on low-prime, surface-coated extracorporeal circuitry (FX05, Terumo); Group 2- procedures requiring Tx on coated circuitry; Group 3- Tx-free procedures with standard uncoated circuitry (D902, Sorin); Group 4 (Control)- procedures requiring Tx on uncoated circuitry. Blood samples were collected at baseline (T1), at the end of the CPB (T2) and 24 h (T3) postoperatively. rSO(2) desaturation risk score >6000 (Invos, Somanetics) was calculated by multiplying rSO(2) <50% by time. RESULTS: IL-6 levels (pg/ml) were significantly lower in Groups 1 and 3 versus control at T2 (13±4; 17±5 versus 33±8; p<0.05). CD11b/CD18 levels (%) were significantly lower in Group 1 (12±4) versus control (25±8) at T2 (p<0.05). Respiratory support time (h) was significantly less in Group 1 (11.4±6) versus control (19.8±7) (p<0.05). rSO(2) desaturation risk >6000 (%) was 15.7±9 in Group 1 and 26.8±11 in control (p<0.05). CONCLUSION: Allogenic Tx amplifies the CPB-related inflammatory response. It is feasible to do congenital procedures safely without Tx for patients weighing >10 kg by using combined blood management strategies.

Clinical performance and biocompatibility of hyaluronan-based heparin-bonded extracorporeal circuits in different risk cohorts.

This prospective randomized study compares novel hyaluronan-based heparin-bonded circuits vs. uncoated controls across EuroSCORE patient risk strata including biomaterial evaluation. Over a two-year period, 90 patients undergoing coronary artery bypass grafting were prospectively randomized to one of the two perfusion protocols: Group 1 was treated with hyaluronan-based heparin-bonded preconnected circuits (Vision HFO-GBS, Gish, CA, USA) and Group 2 with identical uncoated controls. Each group was composed of three subgroups (n=15) with respect to preoperative evaluation of low (EuroSCORE 0-2), medium (3-5) and high (6+) risk patients. Blood samples were collected after induction (T1) and heparinization (T2), 15 min after cardiopulmonary bypass start (T3), before cessation of CPB (T4), 15 min after reversal (T5), and the first postoperative day (T6). In high-risk patients, platelet counts demonstrated significant preservation at T4, T5 and leukocyte counts were lower at T5 in hyaluronan group (P

Clinical and biomaterial evaluation of a new condensed dual-function extracorporeal circuit in reoperation for coronary artery bypass surgery.

PURPOSE: This prospective, randomized study compared the clinical performance of three types of circuits: a newly introduced, fully-coated, interchangeable open-closed circuit with a dual configuration (hard shell with a bypass shunt), reduced length, and reduced prime of less than 800 cc (CondECC); a completely coated circuit (ECC); and a similar uncoated, open circuit with standard length and prime (CONT). METHODS: 75 patients undergoing reoperation for coronary revascularization were randomly allocated into three groups (N=25): Group 1: CondECC with shortened tubing, components and an open-closed configuration of low priming volume with a centrifugal pump and a shunt which bypassed the reservoir for closed configuration; Group 2: ECC with a roller pump and hard-shell reservoir; Group 3: CONT. Blood samples for CBC, inflammatory mediators [Interleukin-2 (IL-2), Complement-3a (C3a)] and flow cytometry (CD11b/CD18) were collected after induction (T1) and heparin administration (T2), 15 min after cardiopulmonary bypass (CPB) (T3), before cessation of CPB (T4), 15 min after reversal (T5), and the first postoperative day (T6). RESULTS: Leukocyte counts demonstrated significant increases at T4, T5 in CONT but remained stable in ECC and CondECC (p<0.05). Platelets were preserved better at T4, T5 in both ECC and CondECC study groups (p<0.05). IL-2 and C3a levels were significantly lower at T3, T4, T5 in CondECC and T4, T5 in ECC (p<0.05). Blood protein adsorption analysis demonstrated increased amount of microalbumin on CONT fibers (p<0.05). CONCLUSIONS: The CondECC is a flexible, dual-function, open/closed configuration system that was easy to use, safe and achieved better biocompatibility when compared to coated and uncoated conventional circuits.

Modular behavior of tauD provides insight into the origin of specificity in alpha-ketoglutarate-dependent nonheme iron oxygenases.

Taurine alpha-ketoglutarate dioxygenase (tauD) is one of the best-studied alpha-ketoglutarate (alphaKG)-dependent nonheme iron oxygenases. As with all oxygenases, a fine balance must be struck between generating a species sufficiently reactive for the required chemistry and controlling that species to prevent undesirable side reactions [Klinman JP (2007) Accts Chem Res 40:325-333]. In the case of tauD, the substrate oxidizing species has been shown to be a ferryl-oxo, and the introduction of deuterium at the reactive position of substrate results in an enormous kinetic isotope effect together with a partial uncoupling of oxygen activation from substrate oxidation [Price JC, Barr EW, Glass TE, Krebs C, Bollinger JM (2003) J Am Chem Soc 125:13008-13009]. We have generated a series of site-specific variants at a position that resides directly behind bound substrate (F159 to L, V, A, and G). Decreasing side-chain bulk diminishes the coupling of oxygen activation to C-H cleavage, which is further reduced by substrate deuteration. Despite this impact, oxygen activation remains completely coupled to the oxidative decarboxylation of alphaKG. The concentration of bis-Tris buffer impacts the extent of coupling of oxygen activation to C-H cleavage, implicating the buffer in the uncoupling pathway. These data indicate a critical role for residue 159 in substrate positioning and reaction in tauD and show that minor active-site perturbations in these enzymes could allow for changes in substrate reactivity while maintaining substrate triggering and oxygen binding/activation.

Clinical evaluation of minimized extracorporeal circulation in high-risk coronary revascularization: impact on air handling, inflammation, hemodilution and myocardial function.

OBJECTIVE: We examined intraoperative microembolic signals (GME), inflammatory response, hemolysis, perioperative regional cerebral oxygen saturation (rSO(2)), myocardial protection and desorbed protein amount on oxygenator fibers in high-risk patients undergoing coronary revascularization (CABG) with minimized and conventional cardiopulmonary bypass (CPB). METHODS: Over a ten-month period, 40 Euroscore 6+ patients undergoing CABG were prospectively randomized to one of the two perfusion protocols (N=20): Group 1: minimized extracorporeal circuits (Mini-CPB) (ROCsafe MPC, Terumo, Ann Arbor, MI, USA) and Group 2: conventional extracorporeal circuits (CECC) (Capiox SX18, Terumo, USA). Serum creatinine kinase-MB (CKMB), free hemoglobin, interleukin-6 (IL-6) and C3a levels were measured. Blood samples were collected at T1: following induction of anesthesia; T2: thromboelastography control; T3:15 min after commencement of CPB; T4: before cessation of CPB; T5: 15 min after protamine reversal and T6: ICU. RESULTS: Serum IL-6 levels were significantly lower in the Mini-CPB group at T4 and T5 and C3a levels were significantly less in the Mini-CPB group at T3, T4 and T5 vs. CECC (p<0.01). CKMB levels in coronary sinus blood demonstrated well preserved myocardium in the Mini-CPB group. Percentage expression of neutrophil CD11b/CD18 levels were significantly lower in the Mini-CPB group at T4 and T5 (p<0.05). There were no significant differences in air handling characteristics or free plasma hemoglobin levels in either circuit. rSO(2) measurements were significantly better at T3 and T4 in the Mini-CPB vs. CECC (p<0.05) and always higher in the Mini-CPB during follow-up. Blood protein adsorption analysis of oxygenator membranes demonstrated a significantly increased amount of microalbumin on CECC fibers (p<0.05). CONCLUSION: Mini-CPB provided a comfort and safety level similar to conventional control via satisfactory air handling, attenuated inflammatory response and hemodilution, with a better clinical outcome in patients undergoing high-risk CABG.

Clinical and biomaterial evaluation of hyaluronan-based heparin-bonded extracorporeal circuits with reduced versus full systemic anticoagulation in reoperation for coronary revascularization.

OBJECTIVE: This prospective randomized study compares full and reduced heparinization on novel hyaluronan-based heparin-bonded circuits vs. uncoated controls under challenging clinical setting including biomaterial evaluation. METHODS: 100 patients undergoing reoperation for coronary artery bypass grafting were allocated into two equal groups (n = 50): Group one was treated with hyaluronan-based heparin bonded preconnected circuits (Vision HFOGBS, Gish, California, USA) and Group two with identical uncoated controls (Vision HFO, Gish, USA). In the study group, half of the patients (n = 25) received low-systemic heparin (125 IU/kg, ACT >250 s) or full dose like control group. Blood samples were collected after induction of anesthesia (T1) and heparin administration before cardiopulmonary bypass (CPB) (T2), 15 min after initiation of CPB (T3), before cessation of CPB (T4), 15 min after reversal with protamine (T5), and the first postoperative day at 08: 00 h (T6). RESULTS: Platelet counts were preserved significantly better at T5, T6 in hyaluronan groups (P < 0.05 vs. control). Serum IL-2 levels were significantly lower at T4, T5 in both hyaluronan groups and C3a levels at T4 and T5 only in low-dose group (P < 0.05). Troponin-T levels in coronary sinus blood demonstrated well preserved myocardium in hyaluronan groups. No significant differences in thrombin-antithrombin levels were observed between full and low-dose heparin groups at any time point. Amount of desorbed protein was 1.41 +/- 0.01 in full and 1.43 +/- 0.01 in low dose vs. 1.78 +/- 0.01 mg/dl in control (P < 0.05). CONCLUSION: Hyaluronan-based heparin-bonded circuits provided better clinical outcome and less inflammatory response compared with uncoated surfaces. Reduced systemic heparinization combined with hyaluronan-based heparin-bonded circuits is feasible and clinically well tolerated.

18O kinetic isotope effects in non-heme iron enzymes: probing the nature of Fe/O2 intermediates.

Contrasted here are the competitive 18O/16O kinetic isotope effects (18O KIEs) on kcat/Km(O2) for three non-heme iron enzymes that activate O2 at an iron center coordinated by a 2-His-1-carboxylate facial triad: taurine dioxygenase (TauD), (S)-(2)-hydroxypropylphosphonic acid epoxidase (HppE), and 1-aminocyclopropyl-1-carboxylic acid oxidase (ACCO). Measured 18O KIEs of 1.0102 +/- 0.0002 (TauD), 1.0120 +/- 0.0002 (HppE), and 1.0215 +/- 0.0005 (ACCO) suggest the formation in the rate-limiting step of O2 activation of an FeIII-peroxohemiketal, FeIII-OOH, and FeIV O species, respectively. The comparison of the measured 18O KIEs with calculated or experimental 18O equilibrium isotope effects (18O EIEs) provides new insights into the O2 activation through an inner-sphere mechanism at a non-heme iron center.

Cardiopulmonary bypass recommendations in adults: the northern New England experience.

Using a regional cardiopulmonary bypass (CPB) registry, we compared the practice of CPB at eight northern New England institutions to recently published recommendations. We examined CPB practice among 3597 adult patients undergoing isolated coronary artery bypass grafting surgery from January 2004 to June 2005. Registry variables were used to compare regional CPB practice to recommendations on topics of neurologic protection (pH management, avoidance of hyperthermia, minimizing return of pericardial suction blood, aortic assessment, arterial line filtration), maintenance of euglycemia, reduction of hemodilution, and attenuation of the inflammatory response. We report overall regional practice (regional minimum, maximum). All centers used alpha-stat pH management and arterial line filters. Avoidance of hyperthermia (temperature < 37degrees C) was achieved during 23.4% of procedures (regional minimum, 1.5%; maximum, 83.2%). Minimizing return of pericardial suction blood was achieved in 23.7% of cases (0.7%, 93.6%). Aortic assessment was performed during 45.7% of procedures (1.3%, 98.9%). Maintenance of euglycemia (< 200 mg/dL) was accomplished in 82.7% (57.1%, 97.9%) of cases. Hemodilution (hematocrit < 23% on CPB) was lower for men 32.4% (20.6%, 52.3%) than women 77.9% (64.7% 88.9%). Men were less likely to receive red blood cell transfusions in the operating room (11.0%; 1.8%, 20.9%) than women (54.6%; 30.1%, 70.6%). In an effort to attenuate the inflammatory response, surface coated circuits were used in 83.3% of procedures (8.8%, 100%). During this time, gaps existed between regional CPB practice and recently published recommendations. We continue to prospectively measure CPB practice relating to these recommendations to monitor and improve the care provided to our patients.

Clinical effects of leukofiltration and surface modification on post-cardiopulmonary bypass atrial fibrillation in different risk cohorts.

OBJECTIVE: A manifestation of inflammatory injury to the heart, atrial fibrillation (AF), ranks among the most frequent and potentially life-threatening post-operative complications. METHODS: In a prospective randomized study, 120 patients undergoing CABG were allocated into two groups (N = 60): Group 1: Polymethoxyethylacry late-coated circuits + Leukocyte filters (Terumo,USA); Group 2: CONTROL: Uncoated circuits (Terumo,USA). Each group was further divided into three subgroups (N = 20) with respect to low (Euroscore 0-2), medium (3-5) and high (6+) risk patients. RESULTS: Serum IL-2 levels were significantly lower in the study group at T4 and T5 (p < 0.01). C3a levels showed significant differences in the leukofiltrated group at T4 and T5 (p < 0.05). CPKMB levels demonstrated well-preserved myocardium in the leukofiltration group, post-operatively. AF incidence was 10% (2 patients) in the study and 35% (7 patients) in the control cohorts (p < 0.05). Phagocytic capacity on fibers in filtered patients was significantly lower. CONCLUSION: Leukofiltration and coating significantly reduce the incidence, ventricular rate, and duration of AF after CABG via modulation of systemic inflammatory response and platelet preservation in high risk groups.

Comparison of polymethoxyethylacrylate-coated circuits with leukocyte filtration and reduced heparinization protocol on heparin-bonded circuits in different risk cohorts.

OBJECTIVES: The relative benefits of strategic leukofiltration on polymer-coated and low-dose heparin protocol on heparin-coated circuits were studied across EuroSCORE patient risk strata for three different cohorts. METHODS: In a prospective, randomized study, 270 patients undergoing coronary artery bypass grafting were allocated into three groups (n = 90): Group 1 - polymethoxyethylacrylate-coated circuits + leukocyte filters; Group 2 - polypeptide-based heparin-bonded circuits with reduced heparinization; and Group 3--CONTROL: uncoated circuits. Each group was further divided into three subgroups (n = 30), with respect to low- (EuroSCORE 0-2), medium- (3-5), and high- (6+) risk patients. Blood samples were collected at T1: following induction of anesthesia; T2: following heparin administration; T3: 15 min after CPB; T4: before cessation of CPB; T5: 15 min after protamine reversal; and T6: ICU. RESULTS: In high-risk cohorts, leukocyte counts demonstrated significant differences at T4 and T5 in Group 1, and at T4 in Group 2. Platelet counts were preserved significantly better at T4 and T5 in both groups (p < 0.05 versus control). Serum IL-2 and C3a levels were significantly lower at T3, T4 and T5 in Group 1, and T4 and T5 in Group 2 (p < 0.05). Postoperative bleeding, respiratory support time and incidence of atrial fibrillation were lower in the study groups versus control. Cell counts on filter mesh and heparin-coated fibers/ circuits were significantly higher in the high-risk cohorts versus uncoated fibers. Phagocytic capacity increased on filter mesh, especially in high-risk specimens. SEM evaluation demonstrated better preserved coated circuits. CONCLUSION: Leukofiltration and coating reduced platelet adhesion, protein adsorption, atrial fibrillation and reduced heparinization acted via modulation of systemic inflammatory response in high-risk groups.