Accurate assessment of right heart function before and after long-term left ventricular assist device implantation.

INTRODUCTION: Because end-stage heart failure (HF) often involves both ventricles even if its initial cause was left-sided heart disease, assessment of RV size, geometry and function before, during and after LVAD implantation is of crucial importance. AREAS COVERED: This review discusses the usefulness, benefits, particular challenges and limits of RV assessment in patients with end-stage HF due to primarily impaired LV function who necessitate LVAD support, with or without an additional RV mechanical support. EXPERT OPINION: Although LV unloading often induces reduction of the pulmonary vascular resistance facilitating RV reverse remodeling and functional improvement, drug-refractory RVF after LVAD implantation is not always avoidable. Therefore, patients who need a temporary or long-term biventri-cular mechanical support should already be identified preoperatively or at the latest intraoperatively. Proper assessment of RV function and its adaptability to hemodynamic overloading before LVAD implantation can predict post-implant RVF, thus helping to avoid complications generated by unforeseen RVF in LVAD recipients. Close monitoring of RV size, geometry and function in LVAD recipients with and without additional RV mechanical support is essential for early recognition of imminent RVF in those without RV support and for detection of RV recovery and weaning decision-making in those with a RV support.

Echocardiographic assessment of the right ventricle: Impact of the distinctly load dependency of its size, geometry and performance.

Right ventricular (RV) size, shape and function are distinctly load-dependent and pulmonary load is an important determinant of RV function in patients with congestive heart failure (CHF) due to primary impaired left ventricular function and in those with pre-capillary pulmonary hypertension (PH). In a pressure overloaded RV, not only dilation and aggravation of tricuspid regurgitation, but also systolic dysfunction leading to RV failure (RVF) can occur already before the development of irreversible alterations in RV myocardial contractility. This explains RV ability for reverse remodeling and functional improvement in patients with post-capillary and pre-capillary PH of a different etiology, after normalization of loading conditions. There is increasing evidence that RV evaluation by echocardiography in relation with its loading conditions can improve the decision-making process and prognosis assessments in clinical praxis. Recent approaches to evaluate the RV in relation with its actual loading conditions by echo-derived composite variables which either incorporate a certain functional parameter (i.e. tricuspid annulus peak systolic excursion, stroke volume, RV end-systolic volume index, velocity of myocardial shortening) and load, or incorporate measures which reflect the relationship between RV load and RV dilation, also taking the right atrial pressure into account (i.e. "load adaptation index"), appeared particularly suited and therefore also potentially useful for evaluation of RV contractile function. Special attention is focused on the usefulness of RV echo-evaluation in relation to load for proper decision making before ventricular assist-device implantation in patients with CHF and for optimal timing of listing procedures to transplantation in patients with end-stage pre-capillary PH.

Assessment of right ventricular adaptability to loading conditions can improve the timing of listing to transplantation in patients with pulmonary arterial hypertension.

BACKGROUND: Right ventricle (RV) performance is load dependent, and right-sided heart failure (RHF) is the main cause of death in pulmonary arterial hypertension (PAH). Prediction of RV worsening for timely identification of patients needing transplantation (Tx) is paramount. Assessment of RV adaptability to load has proved useful in certain clinical circumstances. This study assessed its predictive value for RHF-free and Tx-free outcome with PAH. METHODS: Between 2006 and 2012, all potential Tx candidates with PAH, without RHF at the first evaluation, were selected for follow-up (except congenital heart diseases). At selection and at each follow-up, N-terminal prohormone brain natriuretic peptide (NT-proBNP) and the 6-minute walk distance were measured, and RV adaptability to load was assessed by echocardiography. Collected data were tested for the ability to predict RV stability and Tx-free survival. RESULTS: During a 12-month to 92-month follow-up, RHF developed in 23 of 79 evaluated patients, despite similar medication and no differences in initial RV size and ejection fraction compared with the patients who remained stable. However, unstable patients had an initially lower RV load-adaptation index and afterload-corrected peak global systolic longitudinal strain-rate values as well as higher RV dyssynchrony, tricuspid regurgitation, and NT-proBNP levels (p ≤ 0.01). At certain cutoff values, these variables appeared predictive for 1-year and 3-year freedom from RHF and 3-year Tx-free survival. An RV load-adaptation index reduction of ≥20% showed the highest predictive value (90.0%) for short-term (≤1 year) RV decompensation. CONCLUSIONS: Assessment of RV adaptability to load allows prediction of RV function and Tx-free survival with severe PAH during the next 1 to 3 years. This can improve the timing of listing for Tx.

Pediatric heart allocation and transplantation in Eurotransplant.

Pediatric heart allocation in Eurotransplant (ET) has evolved over the past decades to better serve patients and improve utilization. Pediatric heart transplants (HT) account for 6% of the annual transplant volume in ET. Death rates on the pediatric heart transplant waiting list have decreased over the years, from 25% in 1997 to 18% in 2011. Within the first year after listing, 32% of all infants (<12 months), 20% of all children aged 1-10 years, and 15% of all children aged 11-15 years died without having received a heart transplant. Survival after transplantation improved over the years, and in almost a decade, the 1-year survival went from 83% to 89%, and the 3-year rates increased from 81% to 85%. Improved medical management of heart failure patients and the availability of mechanical support for children have significantly improved the prospects for children on the heart transplant waiting list.

Outlier-based identification of copy number variations using targeted resequencing in a small cohort of patients with Tetralogy of Fallot.

Copy number variations (CNVs) are one of the main sources of variability in the human genome. Many CNVs are associated with various diseases including cardiovascular disease. In addition to hybridization-based methods, next-generation sequencing (NGS) technologies are increasingly used for CNV discovery. However, respective computational methods applicable to NGS data are still limited. We developed a novel CNV calling method based on outlier detection applicable to small cohorts, which is of particular interest for the discovery of individual CNVs within families, de novo CNVs in trios and/or small cohorts of specific phenotypes like rare diseases. Approximately 7,000 rare diseases are currently known, which collectively affect ∼6% of the population. For our method, we applied the Dixon's Q test to detect outliers and used a Hidden Markov Model for their assessment. The method can be used for data obtained by exome and targeted resequencing. We evaluated our outlier-based method in comparison to the CNV calling tool CoNIFER using eight HapMap exome samples and subsequently applied both methods to targeted resequencing data of patients with Tetralogy of Fallot (TOF), the most common cyanotic congenital heart disease. In both the HapMap samples and the TOF cases, our method is superior to CoNIFER, such that it identifies more true positive CNVs. Called CNVs in TOF cases were validated by qPCR and HapMap CNVs were confirmed with available array-CGH data. In the TOF patients, we found four copy number gains affecting three genes, of which two are important regulators of heart development (NOTCH1, ISL1) and one is located in a region associated with cardiac malformations (PRODH at 22q11). In summary, we present a novel CNV calling method based on outlier detection, which will be of particular interest for the analysis of de novo or individual CNVs in trios or cohorts up to 30 individuals, respectively.

Influence of size disparity of transplanted hearts on cardiac growth in infants and children.

OBJECTIVE: We aimed to evaluate the influence of size disparity of the transplanted heart on cardiac growth in infant and child recipients by comparing donor body surface area (BSA) and cardiac dimensions during transplantation to the corresponding parameters of the recipient over a period of time. METHODS: A retrospective review of medical and echocardiographic records of 147 children (5.3 ± 4.0; median, 4.1; range, 1 month-15 years) who underwent orthotopic heart transplantation was done. The patients were divided into age groups as follows: less than 1 year (n = 23), 1 to 2 years (n = 26), more than 2 to 5 years (n = 18), more than 5 to 10 years (n = 27), and more than 10 to 15 years (n = 53). Donor/recipient BSA ratio was determined during transplantation. Cardiac dimensions were measured 30 days after transplantation and compared at 1 year, 2 to 5 years, and 5 to 10 years after transplantation. RESULTS: There were no significant differences in the ventricular end-diastolic diameter, volumes, and mass among those with a donor/recipient BSA ratio of less than 0.80, 0.8 to 1.2, and more than 1.2 (P = .80, .44, and .48, respectively). In all the cardiac dimensions and volumes measured, donor-recipient mismatch did not influence the continuous growth of the heart, as indicated by the measured parameters, in accordance with the recipients' increase in BSA over time. All calculated Z-scores at 1 year, 2 to 5 years, and 6 to 10 years after transplantation were normal when indexed to BSA. CONCLUSIONS: This study demonstrates that despite size disparity of a transplanted heart, it undergoes normal growth in diastolic dimensions, volumes, and myocardial mass over time as appropriate for body growth after cardiac transplantation in infants and children.

New prioritization of heart transplant candidates on mechanical circulatory support in an era of severe donor shortage.

BACKGROUND: Nearly all patients receiving heart transplantation (HTx) in Germany are now those listed in urgent status. In this study we review urgency-based allocation policy for HTx candidates with ventricular assist devices (VADs). METHODS: We retrospectively studied 345 adult candidates for de novo HTx. Group U (n = 160) comprised patients primarily listed in urgent status without VAD. Group VAD-45 (n = 167) comprised patients with intended bridging to HTx who survived >45 days after VAD implantation (after initial drop in survival rates). Among these patients, those who died of stroke or were awarded urgent status due to difficulties of coagulation management (thrombus formation, thromboembolism and bleeding) in the first year after VAD implantation were assigned to Group COAG (n = 36), and those who died or were awarded urgent status due to device-related infection in the same period were assigned to Group INF (n = 31). Actuarial survival rates were studied in each group. RESULTS: Survival rates during support in Group VAD-45 were comparable to those during urgent status in Group U. Bridge-to-transplant rate was 63.9% in Group COAG and 58.1% in Group INF. The post-transplant 3-year survival rate of 85.3% in Group COAG was significantly higher than that in Group INF (46.8%, p < 0.01) and Group U (62.4%, p < 0.05). CONCLUSIONS: Patients who have a VAD for >45 days should be awarded some priority for urgent HTx, which is currently prohibited in Germany. Patients listed in urgent status due to difficulties of coagulation management should be prioritized over those listed for device-related infection to make effective use of limited resources.

Preventing heart injury during negative pressure wound therapy in cardiac surgery: assessment using real-time magnetic resonance imaging.

OBJECTIVE: Heart rupture is a devastating complication to negative pressure wound therapy in cardiac surgery. Also, reduced cardiac output during negative pressure wound therapy has been reported. The present study aimed to examine the effects of negative pressure wound therapy on the position of the heart in relation to the thoracic wall using magnetic resonance imaging in a porcine sternotomy wound model. METHODS: Six pigs had median sternotomy followed by negative pressure wound therapy at -75, -125, and -175 mm Hg. Real-time magnetic resonance imaging movies (10 images/s) were acquired in a midventricular transverse plane or a midsagittal plane during the application of negative pressure wound therapy. RESULTS: Similar finding were observed at all different negative pressures studied. Negative pressure wound therapy caused the heart to be displaced toward the thoracic wall, and in some cases, the right ventricular free wall bulged into the space between the sternal edges, and the sharp edges of the sternum jutted into and deformed the anterior surface of the right ventricular free wall. These events were not affected by the interposition of 4 layers of paraffin gauze dressing but were hindered by the placement of a rigid barrier between the anterior portion of the heart and the inside of the thoracic wall. CONCLUSION: The results show altered position of the heart in relation to the sternum during negative pressure wound therapy. This may explain 2 potentially hazardous events associated with negative pressure wound therapy, namely, risk for heart rupture and reduced cardiac output. Inserting a rigid barrier over the heart may be a protective measure that is clinically practicable.

Who should be delisted from urgent heart transplantation in Germany?

When German heart transplant candidates receive a ventricular assist device (VAD), the indication for Eurotransplant urgency listing is no longer given unless assist device complications occur. We studied survival rates in these patients and compared them with those of patients with urgency listing. The study cohort consists of 377 heart transplant candidates who were listed in urgent status or received a VAD in our center between 2000 and 2007. We defined the following patient groups: group U (n = 193), patients listed in urgent status primarily; group VADinT (n = 219), patients actively listed without urgency (transplantable) after VAD implantation, and group VADinU (n = 99), patients listed in urgent status after VAD implantation. The survival rates during urgent status in groups U and VADinU and those during VAD support without urgency listing in group VADinT were studied. The survival curves of groups U and VADinU were similar, and 1-month survival rates were 97.7% and 95.9%, respectively. One-month survival rate in group VADinT (85.9%) was worse than in group U (p < 0.0001). Survival rates in patients in urgent status both with and without VAD are satisfactory. However, patients with a VAD in "transplantable" status should be rescued under an urgency-based resource allocation algorithm.

Two-dimensional speckle tracking strain analysis for efficacy assessment of myocardial cell therapy.

The subtle effects of transplanted bone marrow cells (BMC) on regional myocardial behavior in patients with ischemic heart disease are difficult to assess. Novel echocardiographic techniques can quantify regional myocardial deformation (strain) and distinguish between passive and active wall motion. We hypothesized that this technique may help delineate cell therapy-induced changes in regional LV contractility that escape clinical routine studies. Twelve patients with coronary artery disease and impaired LV function (LVEF &<35%) underwent CABG surgery plus intramyocardial injection of autologous bone marrow mononuclear cells. Between two and five predefined segments of ischemic myocardium per patient received BMCs, and untreated ischemic segments served as internal controls. Segmental echocardiographic analysis of peak systolic strain by speckle tracking was performed before and 1 year after surgery and compared with standard wall motion analysis. Two patients died during the follow-up period. In the remaining 10 patients, mean LVEF increased from 24.5 +/- 10% to 32.1 +/- 11% (p = 0.02). A moderate improvement of systolic function was noted in ischemic control segments by both wall motion score (WMS) and 2D strain echocardiography (2DSE). In BMC-treated segments, WMS improved slightly, but the data failed to reach statistical significance. As assessed by 2DSE, however, systolic function of BMC-treated segments improved by nearly 100%. 2DSE proved to detect BMC-induced change with 30-fold higher sensitivity than WMS, and the Receiver Operating Characteristic curve (ROC) confirmed the diagnostic precision of 2DSE (area-under-the-ROC = 0.87). We conclude that echocardiographic speckle tracking two-dimensional strain analysis can detect cell therapy-induced changes in regional contractile function that may escape detection by standard wall motion assessment. Thus, 2DSE may be a useful tool for the further development of clinical cardiac cell therapy.

Pediatric heart transplant candidates with failed donor heart allocation after Eurotransplant urgency listing profit from pretransplant mechanical circulatory support bridging.

Due to the Eurotransplant organ allocation policy, urgency listing for heart transplantation (HTx) remains in force until ventricular assist device (VAD) implantation in Germany. We studied the prognosis of HTx candidates after failed donor heart allocation in urgent status. We studied all adult and pediatric (<18 years) HTx candidates who underwent primary HTx after Eurotransplant urgency listing between January 2001 and December 2006 (Group A-uHTx [A-"u"rgent status "HTx"], n = 99; Group P-uHTx [P-"u"rgent status "HTx"], n = 24) and those to whom donor heart was not urgently allocated before VAD implantation or death in the same period (Group A-fHA [A-"f"ailed "H"eart "A"llocation], n = 21, Group P-fHA [P-"f"ailed "H"eart "A"llocation], n = 10). Mortality rate after urgency listing or primary VAD implantation was studied in each group. In adult patients, 1-year mortality rate after urgency listing in Group A-fHA was 56.8% and significantly higher than in Group A-uHTx (30.6%, P < 0.001, log-rank test). After failed urgent heart allocation, 15 out of 21 patients in Group A-fHA had VAD implantation and two patients (9.5%) underwent HTx after VAD implantation. In pediatric patients, 1-year mortality rate in Group P-fHA was 40.0% and significantly higher than in Group P-uHTx (8.5%, P < 0.05). In Group P-fHA, all 10 patients underwent VAD implantation after failed urgent heart allocation and six patients (60.0%, P < 0.01 vs. Group A-fHA, Fisher's exact test) underwent HTx after VAD implantation. After failed urgent donor heart allocation, pediatric HTx candidates seem to profit more from mechanical circulatory support than adults.

Influence of new Eurotransplant heart allocation policy on outcome of heart transplant candidates in Germany.

BACKGROUND: The Eurotransplant community adopted an urgency-based heart allocation algorithm in August 2000. The effect of the new allocation policy on critically ill patients with end-stage heart failure was studied. METHODS: During 1997-1999 (old algorithm) and 2001-2006 (new algorithm), 661 heart transplant candidates received heart transplantation (HTx) or a ventricular assist device (VAD) at our center. Those patients who received VAD or urgent HTx (decompensated) were assigned to Group D-97 (n = 108) and Group D-01 (n = 307) under the old and new algorithm, respectively, and regarded as critically ill. We defined subgroups of critically ill patients as follows: Group VAD-97 (n = 92) and Group VAD-01 (n = 184), who underwent primary VAD implantation under the old and new allocation algorithm, respectively; and Group UTx-97 (n = 16) and Group UTx-01 (n = 123), who underwent urgent HTx under the old and new algorithm. Group survival rates were studied. RESULTS: Group D-01 had significantly higher survival rates than D-97 (61.7% vs 44.4%, 2-year survival; p < 0.001). The ratio of patients with urgent HTx (Group UTx-01) among the patients in Group D-01 was significantly greater than that in Group D-97 (40.1% vs 14.8%, p < 0.001). Survival rates of Group UTx-01 after urgency listing (71.5% for 2-year survival) were significantly better than those after VAD implantation in Groups VAD-01 and VAD-97. CONCLUSIONS: The new heart allocation algorithm has successfully improved survival rates of critically ill patients, enabling these patients to receive urgent HTx.

Effect of modified ultrafiltration on bivalirudin elimination and postoperative blood loss after on-pump coronary artery bypass grafting: assessment of different filtration strategies.

OBJECTIVE: Bivalirudin has a short elimination half-life of approximately 25 to 30 minutes, but no antidote is available. We assessed the effect of four different strategies of modified ultrafiltration after cardiopulmonary bypass on the bivalirudin elimination and postoperative blood loss. METHODS: Five groups of seven patients undergoing elective "on-pump" coronary artery bypass grafting were enrolled in this controlled randomized investigation. The filtration strategies varied with regard to the filtration flow, the filtrate volume, the addition of vacuum suction to the filter system, and the performance of hemodiafiltration. Filtration was started after weaning from cardiopulmonary bypass (CPB). The cumulative postoperative blood drainage at 12 hours was recorded. RESULTS: Bivalirudin half-life in the control group was 0.6 +/- 0.11 hours, and the blood loss was 958 +/- 472 mL. Hemofiltration with a constant flow of 300 mL/m(2) body surface area/min and a filtrate volume of 3000 mL reduced the elimination half-life significantly to 0.47 +/- 0.11 hours. Adding the process of dialysis to hemofiltration resulted in a half-life of 0.52 +/- 0.04 hours and reduced the 12-hour postoperative blood loss significantly, compared to the control group, to 444 +/- 220 mL. The other strategies failed to augment the bivalirudin elimination and postoperative drainage effectively. CONCLUSION: Zero-balanced modified hemodiafiltration without addition of vacuum suction is effective in improving the elimination of bivalirudin after CPB and reducing the postoperative blood loss. Zero-balanced hemodiafiltration should be considered for the augmented elimination of bivalirudin in complex surgical procedures with a high risk of bleeding complications. However, larger investigations are warranted to confirm these results.

Topical negative pressure therapy of a sternotomy wound increases sternal fluid content but does not affect internal thoracic artery blood flow: assessment using magnetic resonance imaging.

OBJECTIVE: Topical negative pressure therapy has excellent healing effects in poststernotomy mediastinitis. Topical negative pressure therapy reduces bacterial counts, increases wound edge microvascular blood flow and granulation tissue formation, and facilitates healing. No study has yet been performed to examine the effect of topical negative pressure on the blood and fluid content in the sternal bone marrow, which is a crucial component in osteitis. METHODS: Eight pigs underwent median sternotomy, left internal thoracic artery harvesting, followed by topical negative pressure treatment. Magnetic resonance imaging was used to quantify both tissue fluid and/or blood content (T2-weighted short tau inversion recovery [T2-STIR]) and internal thoracic artery blood flow (flow quantification). RESULTS: Before application of topical negative pressure, the T2-STIR signal intensity ratio was lower for the left than for the right hemisternum (left, 1.3; right, 2.6), indicating lower levels of tissue fluid content on the left, devascularized side. On application of topical negative pressure, the T2-STIR signal intensity ratio increased immediately for both the sternal bone and the pectoral muscle (left hemisternum after 4 minutes of topical negative pressure: 2.3), leveled off after 4 minutes, and remained unchanged for the ensuing 40 minutes, suggesting movement of fluid and/or blood into the tissue of the wound edge. Topical negative pressure did not affect blood flow in the right internal thoracic artery. CONCLUSIONS: T2-STIR measurements show that topical negative pressure increases sternotomy wound edge tissue fluid and/or blood content. Topical negative pressure creates a pressure gradient that presumably draws fluid from the surrounding tissue to the sternal wound edge and into the vacuum source. This "endogenous drainage" may be one possible mechanism by which osteitis is resolved by topical negative pressure in poststernotomy mediastinitis.

Destiny of candidates for heart transplantation in the Eurotransplant heart allocation system.

OBJECTIVE: We analyzed the prognosis of candidates for heart transplantation (HTx) after being listed with 'urgent status' for donor heart allocation or after ventricular assist device (VAD) implantation without application for urgent status. METHODS: Urgent status as used in this study refers to both the high urgency (HU) status awarded by Eurotransplant until August 31, 2005 and the urgent (U) status that replaced it from then on. Patients who underwent primary VAD implantation between January 2001 and December 2006 and who were listed as transplantable (T) (group VAD-prim, n=159), and patients listed primarily in urgent status before VAD implantation and/or HTx during the same period (group U-prim, n=168) were enrolled in the study. Group U-prim consists of subgroups: group U-HTx (n=123), who underwent primarily HTx in urgent status; group U-VAD (n=25), who underwent primarily VAD implantation in urgent status; patients who died in urgent status before HTx or VAD implantation (n=6); and patients in urgent status without HTx or VAD implantation (n=14). The survival rate in each group was studied. RESULTS: Survival rates after VAD implantation in group VAD-prim were comparable to those after urgent status listing in group U-prim (67.0% vs 68.5% for 1-year survival, 56.6% vs 65.8% for 2-year survival, respectively). Actuarial survival after listing for urgent status in group U-HTx was significantly better than that in group U-VAD (73.7% vs 46.0% for 1-year survival, p<0.05, log-rank test). Actuarial survival during mechanical circulatory support after the VAD implantation (censored at HTx or weaning from the device) in group VAD-prim was significantly better than that in group U-VAD (80.7% vs 56.2% for 3-month survival, p<0.001, log-rank test). CONCLUSIONS: In order to receive urgent HTx, HTx candidates may choose urgency listing without primary VAD implantation at the risk of failed donor heart allocation in urgent status. However, the prognosis of the patients in the latter situation is poor.

Hemodynamic effects of vacuum-assisted closure therapy in cardiac surgery: assessment using magnetic resonance imaging.

OBJECTIVE: The hemodynamic effects of vacuum-assisted closure therapy in cardiac surgery are debated. The aim of the present study was to quantify cardiac output and left ventricular chamber volumes after vacuum-assisted closure using magnetic resonance imaging, which is known to be the most accurate method for quantifying these measures. METHODS: Six pigs had median sternotomy followed by vacuum-assisted closure treatment in the presence and absence of a paraffin gauze interface dressing. Cardiac output and stroke volume were examined using magnetic resonance imaging flow quantification (breath-hold and real-time). Chamber volumes were assessed using cine magnetic resonance imaging. RESULTS: Cardiac output and stroke volume decreased immediately after application of negative pressures of 75, 125, and 175 mm Hg (13% +/- 1% decrease in cardiac output). Interposition of 4 layers of paraffin gauze dressing over the heart during vacuum-assisted closure therapy resulted in a smaller decrease in cardiac output (8% +/- 1%). CONCLUSIONS: Vacuum-assisted closure therapy results in an immediate decrease in cardiac output, although to a lesser extent than shown previously. Covering the heart with a wound interface dressing lessens the hemodynamic effects of vacuum-assisted closure.

Assessment of hemostatic activation during cardiopulmonary bypass for coronary artery bypass grafting with bivalirudin: results of a pilot study.

OBJECTIVE: Bivalirudin has been successfully used as a replacement for heparin during on-pump coronary artery bypass grafting. This study was conducted to assess the effects of the currently suggested protocol for bivalirudin on hemostatic activation during cardiopulmonary bypass with and without cardiotomy suction. METHODS: Ten patients scheduled for coronary artery bypass grafting were enrolled. Bivalirudin was given with a bolus of 50 mg in the priming solution and 1.0 mg/kg for the patient, followed by an infusion of 2.5 mg . kg(-1) . h(-1) until 15 minutes before the conclusion of cardiopulmonary bypass. Cardiopulmonary bypass was performed with a closed system in 5 patients with and in 5 patients without the use of cardiotomy suction. Blood samples were obtained before and after cardiopulmonary bypass. D-dimers, fibrinopeptide A, prothrombin 1 and 2 fragments, thrombin-antithrombin, and factor XIIa were determined. RESULTS: Values for factor XIIa remained almost unchanged in both groups, indicating a minor effect of contact activation. In patients without cardiotomy suction, post-cardiopulmonary bypass values for D-dimers, fibrinopeptide A, prothrombin 1 and 2 fragments, and thrombin-antithrombin were not significantly increased compared with pre-cardiopulmonary bypass values. In patients with cardiotomy suction, values obtained for these parameters had significantly increased compared with pre-cardiopulmonary bypass values and the values obtained in the group without cardiotomy suction after cardiopulmonary bypass. CONCLUSIONS: With this protocol, hemostatic activation during cardiopulmonary bypass was almost completely attenuated when cardiotomy suction was avoided. Cardiotomy suction results in considerable activation of the coagulation system and should therefore be restricted and replaced by cell saving whenever possible.