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Off-pump coronary artery bypass in octogenarians
Ann Thorac Surg 2000;70:1786 –97
OUTCOMES 2000 SCIENTIFIC ABSTRACTS
The Relationship Between the Reinfusion of Shed Blood and Stroke in Coronary Artery Bypass Grafting Patients DA Stump, JH Levy, and JM Murkin, for the IMAGE Investigators. It has been previously reported that aprotinin use is associated with fewer overt strokes in patients undergoing coronary artery bypass grafting (CABG). However, the mechanism of the apparent neuroprotective effect of aprotinin is unclear and somewhat controversial [1]. In the initial analysis of the results of the International Multicenter Aprotinin Graft Patency (IMAGE) Trial, it was observed that fewer patients in the full-dose aprotinin treatment group had strokes or CVAs than the placebo group. A further analysis of the pooled aprotinin database confirmed this finding (1.1% vs 2.6%). We report here a reanalysis of the data that suggests a straightforward mechanism. The return of shed blood from cardiotomy suction has been demonstrated to increase the number of detectable cerebral lipid microemboli (LME) by a factor of 6 (14/cm2 vs 92/cm2) [2]. We hypothesized that patients receiving aprotinin would have less shed blood returned and have less evidence of neurologic injury than patients in the placebo group. Results. In a preliminary analysis, the CABG patients in the database were separated into two categories: those who received any blood shed blood and those who received none. There was a striking difference in the neurologic complication rate between the groups, with the group receiving shed blood having over three times the number of strokes and CVAs. Also of interest, only 18% of patients receiving aprotinin had over 300 mL of shed blood returned compared with 46% of the placebo group. These data support the premise that the return of shed blood has a negative effect on patient outcome. Further, but unexplained, there was no increased risk of stroke associated with the return of shed blood in the aprotinin group.
1787
The Role of the Systemic Inflammatory Response on S100b Release and Cognitive Function After Cardiac Surgery With Cardiopulmonary Bypass: The Effect of Zero Balanced Ultrafiltration M de Baar, CCP, JC Diephuis, MD, J Holtkamp, MD, and R Hijman, PhD. University Medical Center, Utrecht, The Netherlands Introduction. The inflammatory response, initiated by cardiopulmonary bypass, may be responsible for S100b elevations after cardiac surgery. The primary objective of this study was to determine the effect of a technique, known to reduce SIRS, the so-called zero-balanced ultrafiltration (ZBUF), on postoperative serum S100b levels. Additionally, this study was designed as a pilot study to assess the possible effects of ZBUF on cognitive function. Methods. After approval, 49 patients undergoing an elective coronary artery bypass grafting were randomly assigned to the study group (ZBUF) or control group. Serum S100b levels were measured 5 minutes after intubation, at the end of bypass, and at 8 and 20 hours after arrival at the intensive care unit. S100b level in the ultrafiltrate was measured at the end of bypass, enabling to calculate the ratio between S100b level in the ultrafiltrate and in blood (serum). Cognitive function was assessed by neuropsychological test battery on the day before the operation and the day before discharge from the hospital. The neuropsychological observers were blinded for the treatment. Results. Immediate postoperative S100b levels were strongly elevated in both groups. S100b was not detectable in the ultrafiltrate, indicating that these results are not obscured by washout of S100b. ZBUF had no relevant effect on cognitive decline.
Table 1. Stroke/CVA Pooled Aprotinin Database Placebo 0/134 (0.0%)a 21/685 (3.1%)a 21/819 (2.6%)b
No reinfusion Reinfusion Overall
p ⫽ 0.04;
a
Aprotinin 2/162 (1.2%) 7/643 (1.1%) 9/805 (1.1%)b
p ⫽ 0.02.
b
Summary. Neuroprotection may be defined as preventing brain injury as well as protecting the brain at the cellular level. Shed blood is a major cause of neurologic insult. Strategies to reduce bleeding and avoid the reinfusion of shed blood are neuroprotective by preventing lipid microembolization and aggravating the systemic inflammatory response. References 1. Murkin et al. J Thorac Cardiovasc Surg 1994;107:554– 61. 2. Stump et al. Ann Thorac Surg 1999;68:1460.
Conclusions. ZBUF during cardiopulmonary bypass does not reduce postoperative S100b release. This result is not affected by washout. ZBUF does not appear to reduce the incidence of neurocognitive deficits. Further study to the effect of ZBUF on cognitive function is not justified; whether SIRS affects cognitive dysfunction remains to be resolved. Issues. Validity of S100b as a marker for cognitive dysfunction.
Off-Pump Coronary Artery Bypass in Octogenarians RG Carlson, MD, JC Schiro, MD, and C Hertz, MSN. Sarasota Memorial Hospital, Sarasota, Florida Introduction. In octogenarians, coronary artery bypass surgery has been associated with increased mortality and morbidity, especially increased stroke rates. We evaluated off-pump techniques in octogenarians and compared the results with a computer-generated matched control group performed with cardiopulmonary bypass (CPB). Methods. Between September 1998 and February 2000, 41 off-pump coronary artery bypass (OPCAB) procedures were performed by two surgeons (83.7 years) using a novel cardiac stabilizer that atraumatically incorporates coronary artery occlusion, and were compared with 70 octogenarians (82.8 years) using CPB before our off-pump experience. Computer-generated matching of comorbidities was performed and postoperative outcomes were compared. Results. There were no severe neurologic events in the OPCAB group compared with 8.5% stroke rate in the CPB group. In the OPCAB group, there was a decreased mortality rate (4.9% vs 7.1%) and reduced atrial fibrillation (14.6% vs 27%). There was also a significant reduction in length of stay (6.5 vs 8.8 days, p ⬍ 0.05). Conclusions. OPCAB is the preferred approach to myocardial revascularization in the high-risk octogenarian group, with a reduction in stroke rate, mortality, and a significant reduction in length of hospital stay.
Cerebral Microembolization After Cardiac Deairing in Children: Is Trendelenburg Better Than Horizontal Head Position? R Rodriguez, MD, PhD, G Cornel, MBBS, N Weerasena, MBBS, and W Splinter, MD. Division of Cardiovascular Surgery, and Department of Anesthesia, Children’s Hospital of Eastern Ontario, Ottawa, Canada Introduction. Residual intracardiac air represents a source of cerebral microembolization in children. Positioning of the patient’s head in Trendelenburg has been suggested for use before aortic declamping. We studied: a) the effects of Trendelenburg head position (THP) on the cerebral microembolic rate as compared with the horizontal head position (HHP) after deairing, and b) the association between embolic rate and the clinical assessment of deairing. Methods. After Internal and External Review Board approval, children requiring surgical exposure of the systemic ventricle were randomized to THP (⫺15) and HHP (0) after standard deairing procedures. Complexity of repair was divided into: group I (single simple lesions) and group II (multiple complex lesions). High-intensity transient Doppler signals (HITS) in the right middle cerebral artery were “counted” within the first 5 minutes after aortic declamping (Release) and from this ending period until cardiopulmonary bypass termination (Residual). A predefined five-point scale was used for blinded assessment of surgical deairing. Results. HITS were identified in 98% of 128 patients (age: 5 days to 206 months). Head position of surgeon did not affect HITS rate ( p⬎0.20). During Residual, HITS count in group II was higher than group I ( p ⫽ 0.01). HITS correlated with the assessment of deairing (Rho ⫽ ⫺0.57, p ⬍ 0.001). Conclusions. THP as a complement of cardiac deairing in children does not degrease the brain microembolic load as compared with HHP. Issues. Cardiac deairing, Trendelenburg head position, and potential sources of microembolization.
OUTCOMES 2000 SCIENTIFIC ABSTRACTS
The Relationship Between the Reinfusion of Shed Blood and Stroke in Coronary Artery Bypass Grafting Patients DA Stump, JH Levy, and JM Murkin, for the IMAGE Investigators. It has been previously reported that aprotinin use is associated with fewer overt strokes in patients undergoing coronary artery bypass grafting (CABG). However, the mechanism of the apparent neuroprotective effect of aprotinin is unclear and somewhat controversial [1]. In the initial analysis of the results of the International Multicenter Aprotinin Graft Patency (IMAGE) Trial, it was observed that fewer patients in the full-dose aprotinin treatment group had strokes or CVAs than the placebo group. A further analysis of the pooled aprotinin database confirmed this finding (1.1% vs 2.6%). We report here a reanalysis of the data that suggests a straightforward mechanism. The return of shed blood from cardiotomy suction has been demonstrated to increase the number of detectable cerebral lipid microemboli (LME) by a factor of 6 (14/cm2 vs 92/cm2) [2]. We hypothesized that patients receiving aprotinin would have less shed blood returned and have less evidence of neurologic injury than patients in the placebo group. Results. In a preliminary analysis, the CABG patients in the database were separated into two categories: those who received any blood shed blood and those who received none. There was a striking difference in the neurologic complication rate between the groups, with the group receiving shed blood having over three times the number of strokes and CVAs. Also of interest, only 18% of patients receiving aprotinin had over 300 mL of shed blood returned compared with 46% of the placebo group. These data support the premise that the return of shed blood has a negative effect on patient outcome. Further, but unexplained, there was no increased risk of stroke associated with the return of shed blood in the aprotinin group.
1787
The Role of the Systemic Inflammatory Response on S100b Release and Cognitive Function After Cardiac Surgery With Cardiopulmonary Bypass: The Effect of Zero Balanced Ultrafiltration M de Baar, CCP, JC Diephuis, MD, J Holtkamp, MD, and R Hijman, PhD. University Medical Center, Utrecht, The Netherlands Introduction. The inflammatory response, initiated by cardiopulmonary bypass, may be responsible for S100b elevations after cardiac surgery. The primary objective of this study was to determine the effect of a technique, known to reduce SIRS, the so-called zero-balanced ultrafiltration (ZBUF), on postoperative serum S100b levels. Additionally, this study was designed as a pilot study to assess the possible effects of ZBUF on cognitive function. Methods. After approval, 49 patients undergoing an elective coronary artery bypass grafting were randomly assigned to the study group (ZBUF) or control group. Serum S100b levels were measured 5 minutes after intubation, at the end of bypass, and at 8 and 20 hours after arrival at the intensive care unit. S100b level in the ultrafiltrate was measured at the end of bypass, enabling to calculate the ratio between S100b level in the ultrafiltrate and in blood (serum). Cognitive function was assessed by neuropsychological test battery on the day before the operation and the day before discharge from the hospital. The neuropsychological observers were blinded for the treatment. Results. Immediate postoperative S100b levels were strongly elevated in both groups. S100b was not detectable in the ultrafiltrate, indicating that these results are not obscured by washout of S100b. ZBUF had no relevant effect on cognitive decline.
Table 1. Stroke/CVA Pooled Aprotinin Database Placebo 0/134 (0.0%)a 21/685 (3.1%)a 21/819 (2.6%)b
No reinfusion Reinfusion Overall
p ⫽ 0.04;
a
Aprotinin 2/162 (1.2%) 7/643 (1.1%) 9/805 (1.1%)b
p ⫽ 0.02.
b
Summary. Neuroprotection may be defined as preventing brain injury as well as protecting the brain at the cellular level. Shed blood is a major cause of neurologic insult. Strategies to reduce bleeding and avoid the reinfusion of shed blood are neuroprotective by preventing lipid microembolization and aggravating the systemic inflammatory response. References 1. Murkin et al. J Thorac Cardiovasc Surg 1994;107:554– 61. 2. Stump et al. Ann Thorac Surg 1999;68:1460.
Conclusions. ZBUF during cardiopulmonary bypass does not reduce postoperative S100b release. This result is not affected by washout. ZBUF does not appear to reduce the incidence of neurocognitive deficits. Further study to the effect of ZBUF on cognitive function is not justified; whether SIRS affects cognitive dysfunction remains to be resolved. Issues. Validity of S100b as a marker for cognitive dysfunction.
Off-Pump Coronary Artery Bypass in Octogenarians RG Carlson, MD, JC Schiro, MD, and C Hertz, MSN. Sarasota Memorial Hospital, Sarasota, Florida Introduction. In octogenarians, coronary artery bypass surgery has been associated with increased mortality and morbidity, especially increased stroke rates. We evaluated off-pump techniques in octogenarians and compared the results with a computer-generated matched control group performed with cardiopulmonary bypass (CPB). Methods. Between September 1998 and February 2000, 41 off-pump coronary artery bypass (OPCAB) procedures were performed by two surgeons (83.7 years) using a novel cardiac stabilizer that atraumatically incorporates coronary artery occlusion, and were compared with 70 octogenarians (82.8 years) using CPB before our off-pump experience. Computer-generated matching of comorbidities was performed and postoperative outcomes were compared. Results. There were no severe neurologic events in the OPCAB group compared with 8.5% stroke rate in the CPB group. In the OPCAB group, there was a decreased mortality rate (4.9% vs 7.1%) and reduced atrial fibrillation (14.6% vs 27%). There was also a significant reduction in length of stay (6.5 vs 8.8 days, p ⬍ 0.05). Conclusions. OPCAB is the preferred approach to myocardial revascularization in the high-risk octogenarian group, with a reduction in stroke rate, mortality, and a significant reduction in length of hospital stay.
Cerebral Microembolization After Cardiac Deairing in Children: Is Trendelenburg Better Than Horizontal Head Position? R Rodriguez, MD, PhD, G Cornel, MBBS, N Weerasena, MBBS, and W Splinter, MD. Division of Cardiovascular Surgery, and Department of Anesthesia, Children’s Hospital of Eastern Ontario, Ottawa, Canada Introduction. Residual intracardiac air represents a source of cerebral microembolization in children. Positioning of the patient’s head in Trendelenburg has been suggested for use before aortic declamping. We studied: a) the effects of Trendelenburg head position (THP) on the cerebral microembolic rate as compared with the horizontal head position (HHP) after deairing, and b) the association between embolic rate and the clinical assessment of deairing. Methods. After Internal and External Review Board approval, children requiring surgical exposure of the systemic ventricle were randomized to THP (⫺15) and HHP (0) after standard deairing procedures. Complexity of repair was divided into: group I (single simple lesions) and group II (multiple complex lesions). High-intensity transient Doppler signals (HITS) in the right middle cerebral artery were “counted” within the first 5 minutes after aortic declamping (Release) and from this ending period until cardiopulmonary bypass termination (Residual). A predefined five-point scale was used for blinded assessment of surgical deairing. Results. HITS were identified in 98% of 128 patients (age: 5 days to 206 months). Head position of surgeon did not affect HITS rate ( p⬎0.20). During Residual, HITS count in group II was higher than group I ( p ⫽ 0.01). HITS correlated with the assessment of deairing (Rho ⫽ ⫺0.57, p ⬍ 0.001). Conclusions. THP as a complement of cardiac deairing in children does not degrease the brain microembolic load as compared with HHP. Issues. Cardiac deairing, Trendelenburg head position, and potential sources of microembolization.