Rajko Radovancevic

Lowering the hemoglobin threshold for transfusion in coronary artery bypass procedures: effect on patient outcome.

BACKGROUND: There is controversy regarding the application of transfusion triggers in cardiac surgery. The goal of this study was to determine if lowering the hemoglobin threshold for red cell (RBC) transfusion to 8 g per dL after coronary artery bypass graft surgery would reduce blood use without adversely affecting patient outcome.

Arteriovenous malformation and gastrointestinal bleeding in patients with the HeartMate II left ventricular assist device

BACKGROUND In this study we investigated gastrointestinal (GI) bleeding and its relationship to arteriovenous malformations (AVMs) in patients with the continuous-flow HeartMate II (HMII) left ventricular assist device (LVAD). METHODS The records of 172 patients who received HMII support between November 2003 and June 2010 were reviewed. Patients were considered to have GI bleeding if they had 1 or more of the following symptoms: guaiac-positive stool; hematemesis; melena; active bleeding at the time of endoscopy or colonoscopy; and blood within the stomach at endoscopy or colonoscopy. The symptom(s) had to be accompanied by a decrease of >1 g/dl in the patients hemoglobin level. The location of the bleeding was identified as upper GI tract, lower GI tract or both according to esophagogastroduodenoscopy, colonoscopy, small-bowel enteroscopy or mesenteric angiography. Post-LVAD implantation anti-coagulation therapy consisted of warfarin, aspirin and dipyridamole. RESULTS Thirty-two of the 172 patients (19%) had GI bleeding after 63 ± 62 (range 8 to 241) days of HMII support. Ten patients had GI bleeding from an AVM; these included 3 patients who had 2 bleeding episodes and 2 patients who had 5 episodes each. Sixteen patients had upper GI bleeding (10 hemorrhagic gastritis, 4 gastric AVM, 2 Mallory-Weiss syndrome), 15 had lower GI bleeding (6 diverticulosis, 6 jejunal AVM, 1 drive-line erosion of the colon, 1 sigmoid polyp, 1 ischemic colitis) and 1 had upper and lower GI bleeding (1 colocutaneous and gastrocutaneous fistula). All GI bleeding episodes were successfully managed medically. CONCLUSIONS Arteriovenous malformations can cause GI bleeding in patients with continuous-flow LVADs. In all cases in this series, GI bleeding was successfully managed without the need for surgical intervention.

Results of HeartMate II left ventricular assist device implantation on renal function in patients requiring post-implant renal replacement therapy

BACKGROUND Renal function is often compromised in patients with advanced heart failure. METHODS We evaluated renal function in heart failure patients supported by the HeartMate II (Thoratec Corporation, Pleasanton, CA) continuous-flow left ventricular assist device (LVAD) who required renal replacement therapy (RRT) by continuous venovenous hemofiltration dialysis (CVVHD) or hemodialysis, or both. Indications for RRT included oliguria (urine < 400 ml/day) unresponsive to diuretic therapy for > 24 hours with a creatinine level > 2.0 mg/dl or 1.5 times that of the pre-implant creatinine level, severe acidemia, and volume overload. RESULTS Of 107 consecutive patients who underwent HeartMate II implantation at our center and had been supported for > 30 days, 15 (13 men and 2 women) required post-implant RRT. Of the 15 patients, 3 received CVVHD and 12 received CVVHD and hemodialysis. Renal function improved within 2 months of support compared with average values before support (creatinine clearance, 64 ± 39 vs 92 ± 55 ml/min, p = 0.041; glomerular filtration rate, 46.9 ± 20.7 vs 73.2 ± 38.9 ml/min/1.73 m(2); p = 0.032). Renal function improved after HeartMate II implantation in 10 patients, and RRT was removed. Of these 10 patients, 2 underwent heart transplantation 4 months after RRT was removed, 1 underwent heart and kidney transplantation 4 years later, 2 died at home of conditions unrelated to renal function 6 months after RRT was removed, and 5 are awaiting heart transplantation, with good quality of life. CONCLUSIONS In this study, patients who experienced clinical recovery after the LVAD implant had subsequent recovery of renal function after continuous-flow LVAD support.

Blood use in patients undergoing repeat coronary artery bypass graft procedures: multivariate analysis

BACKGROUND: The prevailing clinical opinion is that patients undergoing repeat coronary artery bypass graft (CABG) operation require more blood transfusions than do patients undergoing primary CABG operation. To determine the extent of this increased demand and the variables responsible for it, the cases of 196 patients who had undergone primary procedures and 65 patients who had had repeat procedures at the same institution were reviewed.

Increased leukocyte-platelet interactions during circulatory support with left ventricular assist devices.

The interaction of circulating monocytes and platelets may contribute to thrombosis and inflammation in heart failure. We studied platelet and monocyte activation in 15 patients with end-stage heart failure who underwent left ventricular assist device (LVAD) placement. Blood samples were collected before and at 3, 7, 14, 21, 30, 60, 90, and 180 days after LVAD implantation. We used flow cytometry to measure the expression of platelet surface glycoprotein receptors, platelet activation markers, monocyte markers, the formation of platelet complexes with monocytes (MPC), granulocytes, and lymphocytes, and platelet glycoprotein (GP) IIIa (PLA1/A2) polymorphism. The average preoperative percentage of CD62P-positive platelets was 27% ± 17%; CD63-positive platelets, 9.7% ± 8.1%; thrombospondin-positive platelets, 9.9% ± 6.8%; and MPCs, 10.3% ± 4.3%. No significant changes were noted in the percent of activated platelets with the three markers. Percentage of MPCs increased over time and peaked at day 21 (26.3% ± 10.6%, p = 0.0028). In about 40% of patients, activation markers remained high up to 60 days after implantation. We found a significant positive correlation between MPC and CD14 (R = 0.60, p = 0.011), and a negative correlation between MPC and P-selectin glycoprotein ligand-1 (PSGL-1) (R = −0.84, p < 0.0001), and between CD14 and PSGL-1 (R = −0.46, p = 0.022) indicating monocyte activation. These results indicate increased platelet and monocyte activation and interactions in patients undergoing long-term LVAD support.

Morphologic changes in the aortic wall media after support with a continuous-flow left ventricular assist device

BACKGROUND Continuous-flow left ventricular assist devices (LVADs) provide durable, reliable, energy-efficient long-term support. However, the biologic effects of continuous flow are not completely known. Therefore, we examined aortic wall morphology in patients with heart failure before and after prolonged circulatory support with a continuous-flow LVAD. METHODS After applying a partial aortic occlusion vascular clamp in the lower half of the ascending aorta, we removed samples of aortic wall tissue and then attached the outflow graft of the pump. Samples were obtained from 11 patients (9 men and 2 women, mean age 65 ± 7 years) with severe heart failure at the time of LVAD implantation. We obtained matched specimens at explantation after heart transplantation (n = 5) or autopsy (n = 6). These specimens were removed from the distal ascending aorta, remote from the aortic anastomotic site. Tissue sections were stained with hematoxylin and eosin, Movats pentachrome and Massons trichrome. Smooth muscle actin immunohistochemistry was performed on all sections. To evaluate the morphology of the aortic wall media, we quantitatively graded tissue sections for medial thickness, medial degenerative changes, smooth muscle cell (SMC) disorientation and depletion, elastic fiber fragmentation and depletion, medial fibrosis and atherosclerotic changes. RESULTS The mean duration of support was 140 ± 136 days (range 87 to 580 days). The histologic evaluation and comparison of specimens obtained before and after LVAD support showed significantly increased foci of medial degeneration, SMC depletion, elastic fiber fragmentation, medial fibrosis and atherosclerotic changes after LVAD support. Mean medial thickness was not significantly different after LVAD support. We observed similar changes between samples obtained at transplantation and those obtained at autopsy. CONCLUSIONS After continuous-flow LVAD support, the morphology of the aortic wall media was altered in all of our patients. The clinical relevance of these findings is unknown.

Analysis of prolonged storage on coagulation Factor (F)V, FVII, and FVIII in thawed plasma: Is it time to extend the expiration date beyond 5 days?

BACKGROUND: According to AABB standards, fresh‐frozen plasma (FFP) should be thawed at 30 to 37°C and expire after 24 hours. An increase in the aggressive management of trauma patients with thawed plasma has heightened the risk of plasma waste. One way to reduce plasma waste is to extend its shelf life, given that the full range of therapeutic efficacy is maintained. We evaluated the effect of prolonged storage at 1 to 6°C on the activity of Factor (F)V, FVII, and FVIII in plasma thawed at 37 or 45°C.

Significance of anaemia in patients with advanced heart failure receiving long-term mechanical circulatory support

The aim of this study was to analyse the prognostic impact of anaemia in patients receiving long‐term left ventricular assist device (LVAD) support.

Comparison of intravenous ganciclovir and cytomegalovirus hyperimmune globulin pre-emptive treatment in cytomegalovirus-positive heart transplant recipients.

BACKGROUND We compared the use of intravenous ganciclovir and cytomegalovirus hyperimmune globulin (CMVIG) as a pre-emptive treatment for cytomegalovirus (CMV)-positive heart transplant recipients. METHODS Of 59 CMV-seropositive adult heart transplant recipients enrolled in Group 1, 37 tested positive for pp65 antigen within 12 weeks post-transplantation. These patients were randomized to receive either intravenous ganciclovir (n = 23) or CMVIG (n = 14). Group 2 included 133 CMV-seropositive heart transplant recipients who were not tested for CMV antigenemia and who received no anti-CMV therapy. RESULTS CMV disease developed in 0 of 59 patients from Group 1, and in 27 of 133 patients (20%) in Group 2 (p = 0.0001). The incidence of superinfections was lower in Group 1 (0.28 +/- 0.46) than in Group 2 (1.10 +/- 1.33) (p = 0.01). The 2 groups did not differ with regard to incidence of rejection (0.7 +/- 0.9 in Group 1 vs 1.0 +/- 1.2 in Group 2; p = NS), transplant coronary artery disease at 1 year (14% in Group 1 vs 16% in Group 2; p = NS) or post-transplant lymphoproliferative disease (0% in Group 1 vs 2% in Group 2; p = NS). Ganciclovir and CMVIG therapies were associated with similar rates of rejection (0.52 +/- 0.6 with ganciclovir vs 0.50 +/- 0.60 with CMVIG; p = NS), superinfection (0.30 +/- 0.48 with ganciclovir vs 0.25 +/- 0.46 with CMVIG; p = NS), and transplant coronary artery disease at 1 year (13% with ganciclovir vs 14% with CMVIG, p = NS). CONCLUSIONS The pre-emptive anti-CMV approach is superior to prophylaxis in CMV-seropositive heart transplant recipients. Both ganciclovir and CMVIG are equally effective.

Urgent exchange of a HeartMate II left ventricular assist device after percutaneous lead fracture.

In four of our patients implanted with the HeartMate II left ventricular assist device (LVAD), fraying and fracture of the percutaneous leads internal wires led to pump failure. The patients included two adolescent males (age, 15 and 17 years), one adult male (age, 78 years), and one adult female (age, 49 years). The damage was attributed to patient-related twisting or kinking of the lead. The patients had been supported by the LVAD for 6-18 months before the lead was damaged. In each case, audible and visual alarms were activated, and the pump temporarily continued to function well. The patients were rushed to the hospital, and the pumps were exchanged. All four patients recovered uneventfully and were discharged from the hospital 10-14 days later. They continued to do well on LVAD support for up to 639 days after the initial implant procedure. These events show the importance of educating LVAD patients to avoid excessive twisting or kinking of the devices driveline.