Development and results of Puglia adult cardiac surgery registry.

AIMS: To evaluate the feasibility of a cardiac surgery registry and to describe patients' characteristics, type of procedures performed, incidence of postoperative complications with short and middle-term mortality. METHODS: A database with clinical information and details on cardiac surgical operations was implemented by Puglia Health Regional Agency to collect data of each cardiac surgery procedure performed in the seven adult cardiac surgery centres of the region. Health regional agency personnel guaranteed data accuracy and quality control procedures. Mortality after the discharge was evaluated for residents in Puglia by linking clinical data to the Health Information System. RESULTS: From January 2011 to December 2012, 6429 operations were performed. All operations were included in the registry with very high completeness of collected data (95.3% per patient). The majority of the operations performed were coronary artery bypass graft alone (41.1%), valve surgery alone (26.2%), coronary artery bypass graft and valve surgery (11.4%), or valve with other surgery (11.8%). During a median follow-up of 12 months (interquartile range 6-18 months), 211 deaths were detected after the discharge. Overall, cumulative mortality from the operation was 8.2% at 6 months and 9.5% at 12 months. CONCLUSION: Implementation of a regional clinical registry of cardiac surgery is feasible with a great level of accuracy and the evaluation of mid-term mortality overcomes the limited value of hospital mortality. An accurate cardiac surgery registry elicits epidemiologic evaluations, comparisons between expected and observed mortality, incidence of postoperative complications and encourages a reliable public reporting.

Antithrombin administration in patients with low antithrombin values after cardiac surgery: a randomized controlled trial.

BACKGROUND: Antithrombin (AT) concentrations are reduced after cardiac surgery with cardiopulmonary bypass compared with the preoperative levels. Low postoperative AT is associated with worse short- and mid-term clinical outcomes. The aim of the study is to evaluate the effects of AT administration on activation of the coagulation and fibrinolytic systems, platelet function, and the inflammatory response in patients with low postoperative AT levels. METHODS: Sixty patients with postoperative AT levels of less than 65% were randomly assigned to receive purified AT (5000 IU in three administrations) or placebo in the postoperative intensive care unit. Thirty patients with postoperative AT levels greater than 65% were observed as controls. Interleukin 6 (a marker of inflammation), prothrombin fragment 1-2 (a marker of thrombin generation), plasmin-antiplasmin complex (a marker of fibrinolysis), and platelet factor 4 (a marker of platelet activation) were measured at six different times. RESULTS: Compared with the no AT group and control patients, patients receiving AT showed significantly higher AT values until 48 hours after the last administration. Analysis of variance for repeated measures showed a significant effect of study treatment in reducing prothrombin fragment 1-2 (p=0.009; interaction with time sample, p=0.006) and plasmin-antiplasmin complex (p<0.001; interaction with time sample, p<0.001) values but not interleukin 6 (p=0.877; interaction with time sample, p=0.521) and platelet factor 4 (p=0.913; interaction with time sample, p=0.543). No difference in chest tube drainage, reopening for bleeding, and blood transfusion was observed. CONCLUSIONS: Antithrombin administration in patients with low AT activity after surgery with cardiopulmonary bypass reduces postoperative thrombin generation and fibrinolysis with no effects on platelet activation and inflammatory response.

Anti-inflammatory strategies to reduce acute kidney injury in cardiac surgery patients: a meta-analysis of randomized controlled trials.

Acute kidney injury (AKI) after cardiac operations is a serious complication associated with postoperative mortality. Multiple factors contribute to AKI development, principally ischemia-reperfusion injury and inflammatory response. It is well proven that glucocorticoid administration, leukocyte filter application, and miniaturized extracorporeal circuits (MECC) modulate inflammatory response. We conducted a systematic review of randomized controlled trials (RCTs) in which one of these inflammatory system modulation strategies was used, with the aim to evaluate the effects on postoperative AKI. MEDLINE and Cochrane Library were screened through November 2011 for RCTs in which an inflammatory system modulation strategy was adopted. Included were trials that reported data about postoperative renal outcomes. Because AKI was defined by different criteria, including biochemical determinations, urine output, or dialysis requirement, we unified renal outcome as worsening renal function (WRF). We identified 14 trials for steroids administration (931 patients, WRF incidence [treatment vs. placebo]: 2.7% vs. 2.4%; OR: 1.13; 95% CI: 0.53-2.43; P = 0.79), 9 trials for MECC (947 patients, WRF incidence: 2.4% vs. 0.9%; OR: 0.47; 95% CI: 0.18-1.25; P = 0.13), 6 trials for leukocyte filters (374 patients, WRF incidence: 1.1% vs. 7.5%; OR: 0.18; 95% CI: 0.05-0.64; P = 0.008). Only leukocyte filters effectively reduced WRF incidence. Not all cardiopulmonary bypass-related anti-inflammatory strategies analyzed reduced renal damage after cardiac operations. In adult patients, probably other factors are predominant on inflammation in determining AKI, and only leukocyte filters were effective. Large multicenter RCTs are needed in order to better evaluate the role of inflammation in AKI development after cardiac operations.

Activation of the receptor activator of the nuclear factor-κB ligand pathway during coronary bypass surgery: comparison between on- and off-pump coronary artery bypass surgery procedures.

OBJECTIVES: The receptor activator of the nuclear factor kappa-B (NF-κB) ligand (RANKL), its membrane receptor RANK and its decoy receptor osteoprotegerin (OPG) are all members of the tumour necrosis factor family involved in bone metabolism and immune response. We evaluated the activation of the OPG/RANKL/RANK pathway in patients undergoing cardiac surgery with and without cardiopulmonary bypass (CPB). METHODS: Twenty consecutive patients undergoing elective coronary artery surgery were enrolled in the study and assigned either to the on-pump or to the off-pump group. Pre- and postoperative serum levels of OPG and RANKL were evaluated by enzyme-linked immunosorbent assay; gene expression of OPG, RANKL, RANK and NF-κB p50 subunits were determined by real-time polymerase chain reaction in peripheral blood T-cells and monocytes. RESULTS: Serum levels of OPG significantly increased after surgery in both groups, whereas serum levels of RANKL did not differ over time. T-cells from the on-pump group showed increased gene expression of OPG, RANKL and RANK after the intervention, whereas no mRNA variation for these genes was detected in T-cells from off-pump patients. Gene expression of p50 subunit increased in T-cells and monocytes from both groups. CONCLUSIONS: Cardiac surgery induces the activation of the OPG/RANKL/RANK pathway; both on- and off-pump procedures are associated with increased postoperative OPG serum levels and up-regulation of the NF-κB p50 subunit.

Hemostasis alterations in patients with acute aortic dissection.

BACKGROUND: Surgery for acute aortic dissection (AAD) is frequently complicated by excessive postoperative bleeding and blood product transfusion. Blood flow through the nonendothelialized false lumen is a potential trigger for the activation of the hemostatic system; however, the physiopathology of the aortic dissection induced coagulopathy has never been precisely studied. The aim of the present study is the evaluation of the coagulation and fibrinolytic systems and platelet activation in patients undergoing surgery for AAD. METHODS: Eighteen patients undergoing emergent surgery for Stanford type A AAD were enrolled in the study. The activation of the coagulation and fibrinolytic systems and platelet activation were evaluated at 6 different time points before, during, and after the operation, measuring prothrombin fragment 1.2 (F1.2), plasmin-antiplasmin complex, and platelet factor 4, respectively. RESULTS: All measured biomarkers were increased before, during, and after the operations indicating a systemic activation of coagulation, fibrinolysis, and platelets. These changes were pronounced even preoperatively (T0), and soon after the beginning of cardiopulmonary bypass (T1) when the influence of hypothermia and prolonged cardiopulmonary bypass time were not yet involved. Time from symptom onset to intervention inversely correlated with preoperative F1.2 (r=-0.75; p=0.002) and plasmin-antiplasmin levels (r=-0.57; p=0.034). CONCLUSIONS: Blood flow through the false lumen is a powerful activator of the hemostatic system even before the operation. This remarkable activation may influence postoperative outcome of AAD patients.

Protective effects of steroids in cardiac surgery: a meta-analysis of randomized double-blind trials.

OBJECTIVE: Cardiac surgery and cardiopulmonary bypass (CPB) induce an acute inflammatory response contributing to postoperative morbidity. The use of steroids as anti-inflammatory agents in surgery using CPB has been tested in many trials and has been shown to have good anti-inflammatory effects but no clear clinical advantages for the lack of an adequately powered sample size. The aim of this study was to evaluate the effects of steroid treatment on mortality and morbidity after cardiac surgery. DESIGN: A systematic meta-analysis of randomized double-blind trials (RDBs). SETTING: A university hospital. PARTICIPANTS: Adult patients who underwent cardiac surgery. MEASUREMENTS AND MAIN RESULTS: A trial search was performed through PubMed and Cochrane databases from 1966 to January 2009. Among 104 clinical trials reviewed, 31 RDB trials (1,974 patients) were considered suitable to be analyzed. A quality assessment of the trials was performed using the Jadad score. The types of steroid used in these trials were methylprednisolone (51.4%), dexamethasone (34.3%), hydrocortisone (5.7%), prednisolone (2.9%), or a combination of methylprednisolone and dexamethasone (5.7%). Steroid prophylaxis provided a protective effect preventing postoperative atrial fibrillation (odds ratio = 0.56; confidence interval [CI] 0.44-0.72, p < 0.0001), reducing postoperative blood loss (mean difference = -204.2 mL; CI from -287.4 to -121 mL; p < 0.0001), and reducing intensive care unit (mean difference = -6.6 hours; CI from -10.5 to -2.7 hours, p = 0.0007) and overall hospital stay (mean difference = -0.8 days; CI from -1.4 to -0.2 days, p = 0.01). Steroid prophylaxis had no effect on postoperative mortality, mechanical ventilation duration, re-exploration for bleeding, and postoperative infection. CONCLUSIONS: A systematic review of RDB trials reveals that steroid prophylaxis may reduce morbidity after cardiac surgery and does not increase the risk of postoperative infections.

Preoperative cardiac troponin I to assess midterm risks of coronary bypass grafting operations in patients with recent myocardial infarction.

BACKGROUND: The optimal timing for coronary artery bypass grafting (CABG) in patients with recent acute myocardial infarction (AMI) is unclear. Cardiac troponin I (cTnI) is a widely accepted biomarker of myocardial damage. The objective of this study was to determine whether preoperative cTnI values could be used to determine risk stratification for CABG operations in patients with recent AMI. METHODS: Evaluated were 184 patients who sustained an AMI within 21 days of undergoing nonurgent CABG operations. They were divided into two groups according to their preoperative cTnI values: 117 patients with cTnI of 0.15 ng/mL or less and 67 with cTnI exceeding 0.15 ng/mL. Associations between study variables and events were assessed with logistic regression modelling. Time from AMI to operation was evaluated to define preoperative cTnI variation. RESULTS: Values of cTnI tended to decrease when the interval between AMI and the operation increased. Preoperative cTnI values were significantly associated with a higher incidence of major postoperative complications (low cardiac output syndrome, intraaortic balloon pump necessity, mechanical ventilation >72 hours, acute renal failure, in-hospital mortality). Perioperative myocardial damage was more pronounced in patients with cTnI exceeding 0.15 ng/mL. Multivariate analyses revealed cTnI exceeding 0.15 ng/mL was an independent predictor for 6-month mortality (odds ratio, 3.7; p = 0.043). CONCLUSIONS: Preoperative cTnI exceeding 0.15 ng/mL in patients with recent AMI undergoing CABG is associated with higher postoperative myocardial damage and is a strong determinant of postoperative morbidity and mortality within the 6-month period.

Coagulation-fibrinolysis changes during off-pump bypass: effect of two heparin doses.

BACKGROUND: To date, no study has tested the effect of different heparin dosages on the hemostatic changes during off-pump coronary artery bypass graft (OPCABG) surgery, and a wide variety of empirical anticoagulation protocols are being applied. We tested the effect of two different heparin dosages on the activation of the hemostatic system in patients undergoing OPCABG procedures. METHODS: Forty-two patients eligible for OPCABG procedures were assigned in a randomized fashion to low-dose heparin (150 IU/kg) or high-dose heparin (300 IU/kg). Prothrombin fragment 1+2, plasmin/alpha(2)-plasmin inhibitor complex, D-dimer, soluble tissue factor, tissue factor pathway inhibitor, total thrombin activatable fibrinolysis inhibitor (TAFI), and activated TAFIa were assayed by specific enzyme-linked immunosorbent assays at six different timepoints, before, during, and after surgery. Platelet function was evaluated by means of an in vitro bleeding time test, platelet function analyzer-100. RESULTS: The OPCABG surgery was accompanied by significant changes of all plasma biomarkers, indicative of systemic activation of coagulation and fibrinolysis. A significant increase in circulating TAFIa was detected perioperatively and postoperatively, and multiple regression analysis indicated that prothrombin F1+2 but not plasmin/alpha(2)-antiplasmin complex was independently associated with TAFIa level. Platelet function analyzer-100 values did not change significantly after OPCABG. All hemostatic changes were similar in the two heparin groups, even perioperatively, when the difference in anticoagulation was maximal. CONCLUSIONS: Both early and late hemostatic changes, including TAFI activation, are similarly affected in the low-dose and high-dose heparin groups, suggesting that the increase in heparin dosage is not accompanied by a better control of clotting activation during OPCABG surgery.

Diagnosis of acute aortic dissection by D-dimer: the International Registry of Acute Aortic Dissection Substudy on Biomarkers (IRAD-Bio) experience.

BACKGROUND: D-dimer has been reported to be elevated in acute aortic dissection. Potential use as a "rule-out" marker has been suggested, but concerns remain given that it is elevated in other acute chest diseases, including pulmonary embolism and ischemic heart disease. We evaluated the diagnostic performance of D-dimer testing in a study population of patients with suspected aortic dissection. METHODS AND RESULTS: In this prospective multicenter study, 220 patients with initial suspicion of having acute aortic dissection were enrolled, of whom 87 were diagnosed with acute aortic dissection and 133 with other final diagnoses, including myocardial infarction, angina, pulmonary embolism, and other uncertain diagnoses. D-dimer was markedly elevated in patients with acute aortic dissection. Analysis according to control disease, type of dissection, and time course showed that the widely used cutoff level of 500 ng/mL for ruling out pulmonary embolism also can reliably rule out aortic dissection, with a negative likelihood ratio of 0.07 throughout the first 24 hours. CONCLUSIONS: D-dimer levels may be useful in risk stratifying patients with suspected aortic dissection to rule out aortic dissection if used within the first 24 hours after symptom onset.

D-dimers are not always elevated in patients with acute aortic dissection.

In patients with acute aortic dissection, an early diagnosis is essential to anticipate aortic rupture, cardiac tamponade, organ ischemia and improve surgical results. A specific blood laboratory marker able to rule out the presence of aortic dissection has not been identified yet. Recently, several studies suggested using D-dimers as a negative predicting test to rule out diagnosis of acute aortic dissection in patients presenting with chest pain. In 61 patients with confirmed aortic dissection, preoperative D-dimers were assayed and correlated with time from symptom onset and extension of the false lumen dissection (according with De Bakey classification). Abnormal D-dimers values were considered those being greater than 400 microg/l. D-dimers values were above 400 microg/l in 50 patients (82%) and below 400 microg/l in 11 patients (18%). There was no correlation between preoperative D-dimers values and time from symptoms onset (r = -0.232; P = 0.1). We found that D-dimers are not always elevated in patients presenting with acute aortic dissection. Given the potential devastating effects of denying the diagnosis of acute aortic dissection with consequent delay of adequate treatment, a word of caution regarding the negative predictive value of D-dimer test in the diagnosis of aortic dissection seems warranted.

BNP in mitral valve restrictive annuloplasty for ischemic mitral regurgitation.

Restrictive annuloplasty with undersized mitral rings is used to correct functional mitral regurgitation (MR) in patients with ischemic left ventricular dysfunction. Seventeen patients with severe coronary artery disease, previous myocardial infarction, moderate/severe functional MR and heart failure symptoms were prospectively evaluated. All patients received CABG associated with restrictive annuloplasty. Preoperatively and 6 months after the operation, clinical evaluation, echocardiography and blood sampling for BNP measurement were performed. Operative mortality occurred in 1 patient. MR degree decreased from 3.8+/-0.3 to 1.0+/-0.7 (p<0.01), LVEF increased from 36+/-11% to 43+/-8% (p<0.05), left ventricular end diastolic diameters changed from 54.7+/-5.2 mm to 51.5+/-5.8 mm (p=0.51). NYHA class improved from 2.94+/-1.02 to 1.21+/-0.42 (p<0.01). Mean plasma BNP levels decreased from 471+/-248 pmol/l to 55.6+/-52.8 pmol/l (p<0.05). Restrictive mitral annuloplasty is a safe procedure to be associated to CABG operation. We demonstrated mid-term reduction of BNP plasma values after MR correction thus suggesting the effectiveness of surgical treatment in modifying natural history of the disease.

Antithrombin after cardiac surgery: implications on short and mid-term outcome.

BACKGROUND: Antithrombin (AT) drop during cardiac surgery has been described. The causes and the effects of this phenomenon are not clear. The objective of the study is to evaluate the relationship of AT postoperative values on short and mid-term outcome after cardiac surgery. METHODS: Between January and June 2005, 405 patients, who underwent cardiac operations at our Institution had AT values available preoperatively and postoperatively. Using Receiver Operating Characteristic curves, a cut-off equal to 63.7% for ICU-arrival AT was chosen in order to divide the entire population in two groups (117 patients with ICU-arrival AT < 63.7%, Low AT group, and 288 patients with ICU-arrival AT > or = 63.7%, High AT group). Objective of the study was to evaluate the predictive role of ICU-arrival AT < 63.7% on in-hospital mortality and morbidity and on 18 months follow-up after cardiac surgery. RESULTS: ICU-arrival AT was significantly lower than preoperative AT (90.7 +/- 16.3% vs. 71.2 +/- 15.1%, P < 0.0001). Patients in the Low AT group were older, more often female, had a worse Euroscore and required longer CPB duration and cross clamp time. They had significantly higher preoperative and postoperative D-dimer levels. ICU arrival AT < 63.7% was not associated with increased in-hospital mortality but it was an independent risk factor for longer mechanical ventilation, need of inotropic support, excessive bleeding and blood products transfusion. ICU arrival-AT < 63.7% was associated with worse survival during 18 months follow up (92.3% vs. 85.4% in the High AT and Low AT group, respectively, P = 0.05). CONCLUSIONS: Low AT after cardiac surgery is associated with higher incidences of peri-operative complications and worse survival in the mid-term. Future studies should clarify the pathophysiologic mechanism of this findings and possible therapeutic directions.

Preliminary experience with the smooth muscle troponin-like protein, calponin, as a novel biomarker for diagnosing acute aortic dissection.

AIMS: The early diagnosis of acute aortic dissection (AD) remains challenging. We sought to determine the utility of the troponin-like protein of smooth muscle, calponin, as a diagnostic biomarker of acute AD. METHODS AND RESULTS: Immunoassays against calponin (acidic, basic, and neutral isoforms) were developed and the levels were compared in a convenience sample of 59 patients with radiographically proven AD [34 males, age 59 +/- 15 (SD) years] vs. 158 patients suspected of having AD at presentation (116 males, age 63 +/- 15 years) but whose final diagnosis was not AD. Basic calponin, which is the most specific and abundant in smooth muscle, and acidic calponin, respectively, showed greater than two-fold and three-fold elevations in patients with acute AD. Diagnostic performance as determined by receiver-operating characteristics curve analysis showed that both acidic and basic calponin have the potential to detect AD in the first 24 h [respective areas under the curve (AUCs) 0.63 and 0.58], with superior performance of basic calponin (when compared with acidic) in the initial 6 h (respective AUCs 0.63 and 0.67). CONCLUSION: Circulating calponin levels were elevated in acute AD compared with controls. These biomarkers have the potential for use as an early diagnostic biomarker for acute AD.

Myocardial injury after off-pump coronary artery bypass grafting operation.

OBJECTIVE: Perioperative myocardial ischemia is less pronounced in off-pump coronary artery bypass (OPCAB) compared to on-pump coronary artery bypass; however, the threshold over which the postoperative release of cardiac troponin I (cTnI) release and creatine kinase-MB (CK-MB) after OPCAB should be considered clinically relevant is unknown. The study was designated to evaluate if perioperative myocardial damage, measured by means of postoperative release of cTnI and CK-MB, has an influence on short- and mid-term outcome after OPCAB operations. METHODS: Two hundred and sixty-one unselected patients undergoing OPCAB had cTnI and CK-MB measured preoperatively and nine times postoperatively. Postoperative peak values were evaluated and the 80th percentiles were used to segregate the population into two groups for each marker. The following cut-offs were used: 7.1 ng/dl for cTnI peak and 36.3 ng/dl for CK-MB peak. RESULTS: Patients with cTnI>7.1 ng/ml (n=51) and CK-MB>36.3 ng/ml (n=48) had a longer mechanical ventilation and ICU length of stay. Nevertheless, hospital mortality did not differ between groups. Survival after 3 years was 92.8+/-2.3% and 81.8+/-6.2 for patients with postoperative cTnI peak7.1 ng/ml, respectively (p=0.003). It was 93+/-2.2% and 80+/-6.8% for patients with CK-MB36.3 ng/ml, respectively (p=0.005). Adjusted hazard ratios for mid-term mortality were HR 2.7 (CI 1-7.6), p=0.05 for cTnI>7.1 ng/dl and HR 3.1 (CI 1-9.1), p=0.04 for CK-MB>36.3 ng/ml. CONCLUSION: Perioperative myocardial damage should not be considered an innocuous event following OPCAB operations since the survival rate over 3 years is significantly worse in patients with the highest postoperative peak release of cTnI and CK-MB.

Post-traumatic blunt rupture of the aorta: endo-aortic stenting therapy.

With the increased use of the endovascular approach, the management and outcome of traumatic aortic injuries have changed dramatically over the past 10 years. Understanding pathogenic mechanism underlying aortic injury is critical in choosing the kind of stent-graft to be used. The possible mechanisms of non-penetrating blunt trauma of the aorta have been studied for a long time and are not completely clarified yet. The principal hypotheses concern the differential acceleration and deceleration movements exerting in horizontal and/or longitudinal planes, associated with the abrupt increase of endoluminal pressure and direct or indirect compression of the thoracic aorta from the ribcage structures. When blunt chest trauma causes direct compression of the sternum and spine with a sudden increase in endoluminal pressure, the rupture more frequently involves the ascending aorta or the descending thoracic aorta downstream the isthmus area. On the other hand, when the trauma generates differential acceleration and deceleration movements the rupture involves more frequently the isthmus because this region represents one of the points of fixity of the aorta through the junction of the ligamentum arteriosus and the first ribs. The following presentation is aimed at illustrating some of the possible pathophysiological mechanisms of post-traumatic blunt rupture of the aorta and the indications for its endovascular treatment.

Preoperative C-reactive protein predicts mid-term outcome after cardiac surgery.

BACKGROUND: C-reactive protein (CRP) is a known risk factor for cardiovascular events in the healthy population and in patients with coronary artery disease. High CRP levels before cardiac surgery are associated with worse short-term outcome, but its role after discharge home remains unknown. The study objective was to evaluate the effect of CRP on short-term and mid-term outcome after cardiac surgery. METHODS: From August 2000 to May 2004, values for preoperative CRP were available for 597 unselected patients undergoing cardiac operations. CRP was used to divide this cohort in two groups: a low inflammatory status (LHS) group of 354 patients with CRP of less than 0.5 mg/dL, and a high inflammatory status (HIS) group of 243 patients with a CRP of 0.5 mg/dL or more. Follow-up lasted a maximum of 3 years (median, 1.8 +/- 1.5 years) and was 92.6% complete. RESULTS: In-hospital mortality was 8.2% in the HIS group and 3.4% in the LIS group (odds ratio [OR], 2.61; p = 0.02). Incidence of postoperative infections was 16.5% in the HIS group and 5.1% in the LIS group (OR, 3.25; p = 0.0001). Sternal wound infections were also more frequent in the HIS group (10.7% versus 2.8%; OR, 3.43; p = 0.002). During follow-up, the HIS group had worse survival (88.5% +/- 2.9% versus 91.9% +/- 2.5%; OR, 1.93; p = 0.05) and a higher need of hospitalization for cardiac-related causes (73.6% +/- 6% versus 86.5% +/- 3.2%; OR, 1.82; p = 0.05). CONCLUSIONS: Patients undergoing cardiac surgery with a CRP level of 0.5 mg/dL or more are exposed to a higher risk of in-hospital mortality and postoperative infections. Despite surgical correction of cardiac disease, a high preoperative CRP value is an independent risk factor for mid-term survival and hospitalization for cardiac causes.

Activation of the coagulation system during coronary artery bypass grafting: comparison between on-pump and off-pump techniques.

OBJECTIVE: The activation of the coagulation and fibrinolytic systems and platelet function in patients undergoing coronary artery bypass surgery on-pump or off-pump techniques was compared. METHODS: Thirty-two patients were randomly assigned to on-pump or off-pump coronary artery bypass grafting. Heparin was given at the same dose. Activation of the coagulation and fibrinolytic systems was evaluated by measurement of several markers. Platelet function was evaluated by in vitro bleeding time test. Blood samples were collected at 7 different times, up to postoperative day 6. RESULTS: Overall tissue factor production was similar in the two groups. Thrombin formation was more elevated in the on-pump group (P < .001), particularly during the operation; prothrombin fragment 1.2 discharge values were higher than the preoperative ones (P = .002). Levels of tissue-plasminogen activator showed no difference between the groups (P = .1). D-dimers release was higher in the on-pump group (P = .0002). In vitro bleeding time was longer in the on-pump group (P < .0001), particularly in the first 24 hours; it was not prolonged in the off-pump group. In both groups, regardless of aspirin treatment, discharge in vitro bleeding times were lower than the preoperative ones (P < .01). CONCLUSION: Although the extrinsic coagulation pathway is similarly activated, thrombin formation is more pronounced in patients having on-pump bypass grafting. Patients subjected to off-pump bypass grafting have normally functioning platelets and a weak activation of the fibrinolytic system. At discharge, both groups have preserved platelet function and increased thrombin formation. Further studies with angiographic evaluation are needed to establish a correlation between coagulation parameters, platelet function, and graft patency.

Hemodynamics in off-pump surgery: normal versus compromised preoperative left ventricular function.

OBJECTIVE: Off-pump coronary surgery (OPCABG), avoiding cardiopulmonary bypass and cardioplegic arrest, seems to be a better choice in patients with poor baseline cardiac function. Since cardiocirculatory collapse could be induced by heart displacement in this group of patients at high risk, a greater pathophysiologic understanding of the hemodynamic derangements occurring in such patients is needed. METHODS: Twenty-eight elective OPCABG patients were evaluated for hemodynamic changes induced by heart displacement, using arterial thermodilution to measure cardiac output and global end-diastolic volume. Hemodynamic parameters were recorded: at baseline; during proper exposure and stabilization of each vessel; and at the end of surgery. Patients were divided into two groups, according to baseline ejection fraction (EF): group A (EF>30%; N=16), group B (EF< or =30%; N=12). RESULTS: Heart displacement induced a significant drop in the cardiac and stroke index, with a lesser decrease of mean arterial pressure because of raised systemic vascular resistance. Preload, measured as global end diastolic volume, significantly decreased in group A, while it remained unchanged or increased in group B. Linear regression between the preload index and left ventricular stroke work was significant only in group A. CONCLUSIONS: Patients with poor baseline cardiac function can well tolerate OPCABG. However, the pathophysiologic modifications underlying the hemodynamic changes are different compared to those in patients with good preoperative cardiac performance.

Blood damage related to cardiopulmonary bypass: in vivo and in vitro comparison of two different centrifugal pumps.

Cardiopulmonary bypass (CPB) induces hemolysis and the activation of the inflammatory and coagulation systems. Several components of the CPB equipment may contribute to such phenomenon. We tested the effects of two differently designed centrifugal pumps (Bio-Pump, Medtronic and Revolution, Cobe) on several markers of hemolysis, coagulation, and inflammation: plasma free hemoglobin,prothrombin fragment 1.2, platelet factor 4, and P-selectin. Twenty patients requiring coronary artery bypass grafting were randomized to undergo CPB with one of the study centrifugal pumps, and 10 experiments (5 for each pump) were performed with a closed loop circuit to assess pumps' performances over 6 circulation hours using human blood. CPB induced a significant elevation of all the tested markers. Neither in the in vivo nor in the in vitro study were significant differences observed between the groups. Because the Revolution centrifugal pump, which was recently designed and distributed, produced results comparable with those obtained with the BioPump, it should be considered as safe as the Bio-Pump to perform clinical CPB.