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Proposed risk-adjusted national cardiac surgical database
Asia Pacific
Heart J 1999;8(1)
Abstracts Of The Cardiothoracic Section 13th Inter Annual ScientQic Congress. RACS
Myocardial Calcium Control Using A Na+/H+Exchange Inhibitor vs Low Calcium In Cardioplegic Solutions Y. Fukuhiro,
S. Pepe, M. Wowk, R. Ou, F.L. Rosenfeldt
Cardiac Surgical Research Unit, Baker Medical Research Institute and Alfred Hospital, Melbourne, Victoria
Background:
Results: Low Ca++ CP (0.25mM Ca++) significantly
Ca++ overload plays an important role in the pathogenesis of ischaemia/reperfusion injury. The standard technique to control Ca++ overload has been to reduce ionised calcium in the cardioplegic solutions (CP). Recent reports suggest that Na+/H+ exchange inhibitors can also prevent Ca++ overload. We set out to compare 3 crystalloid cardioplegic solutions (CP) which might minimise Ca++ overload in comparison with standard cardioplegia: 1) low Ca++ CP; 2) citrate CP (to reduce ionised Ca++); 3) addition of the Na+/H+ exchange inhibitor HOE642 (HOE). Methods: Isolated working rat hearts perfused with oxygenated KrebsHenseleit buffer were subjected to 60 min of cardioplegic arrest and reperfusion. Aortic flow (AF) was measured before and after ischaemia. Myocardial high energy phosphates were measured after reperfusion.
improved recovery of postischaemic function in comparison with standard CP (1 .OmM Ca++); (%AF: 47.6k1.7 vs 58.3*2.5%, ~~0.05). Citrate CP significantly impaired postischaemic function (%AF: without citrate vs citrate, 58.3k2.5 vs 22.4+6.2%, ~~0.05). Addition of HOE (1 PM) to CP significantly improved postischaemic function (without HOE vs with HOE, 47.6&l .7 vs 62.4+1.7%, ~~0.05). Cardiac high-energy phosphate levels after arrest and reperfusion were significantly reduced by citrate CP. Conclusions: Lowering Ca++ in CP is beneficial. The use of citrate to chelate Ca++ is detrimental in the crystalloid perfused rat heart. HOE in CP is just as efficacious in preserving the myocardium as is directly reducing Ca++.
Coronary Surgery Rationing In New Zealand: Outcome Analysis Of Delaying CABG In Surgical Candidates H.S. Pannu, B.S. Mallya, P.J. Raudkivi, T.M. Agnew, T.L. Whitlock, S. Stone, D.A. Haydock Department of Cardiothoracic Surgery & Cardiology, Green Lane Hospital, Auckland, New Zealand
Background:
In May 1996 the New Zealand Government introduced a coronary scoring system to ration coronary surgery in the public sector. Methods: 130 patients with coronary scores less than 35 were removed from the bypass waiting list (BWL) and put on a 6-monthly review list. We have reviewed the progress of these 130 patients over a 20-month period. Results: 70 patients (53%) have undergone CABG surgery (61 public, 9 private) during follow-up despite being removed from the waiting list. 24 of these 70 CABG
patients presented with acute coronary syndromes (13 with unstable angina and 6 with myocardial infarcts). Eighteen repeat coronary care admissions (in 13 patients) and 15 repeat coronary angiograms (in 14 patients) were necessary before they had CABG procedures. Five patients died: 1 following CABG, 3 sudden deaths and 1 following MI. Conclusions: The N.Z. scoring system fails to ration appropriately when the threshold for entry to surgery is set at 35 points.
Proposed Risk-adjusted National Cardiac Surgical Database B. Buxton,’
F. Rosenfeldt?
J. Smith? J. Fuller 3
Department of Cardiac Surgery, Austin & Repatriation Medical Centre,’ Heidelberg; Baker Medical Research Institute, Alfred Hospital,2 Prahran; Epworth Hospital,3 Richmond, Victoria
Background:
Accurate recordings of death, complications and risk stratification are essential for quality control and for allocation of health resources. Unadjusted mortality and morbidity figures have little or no meaning. Definitions of risk factors and major complications have been a major problem in the past.
The use of the Society of Thoracic Surgeons (STS) definitions has provided uniformity.1 Methods: Major predictors of operative mortality in patients with coronary artery disease have been defined using logistic regression as: age, ventricular function, reoperation and surgical priority.* Less important variables include
57
Asia Pacific
Heart J 1999;8(1)
Abstracts Of The Cardiothoracic Section 13th Inter Annual Scientific Congress, RACS
number of vessels grafted, diabetes, peripheral and cerebral vascular disease, and so on. The proposal is to extract patient identification and important predictive variables from existing hospital databases in Australia. Patient deaths will be matched with a National Death Index (NDI) held at the Australian Institute of Health and Welfare, which records all deaths occurring in Australia since 1980. Death and other outcomes will be analysed and risk adjusted for the major predictive variables. Conclusions: The development of a risk-adjusted national database linked with the ND1 will provide
accurate and important national figures for operative mortality and major complications which may be used for quality control and improvement of standards.3 References 1. 2.
3.
STS on the Web. Definitions of Terms of the Society of Thoracic Surgeons National Cardiac Surgery Database. Jones RH, Kesler K, Phillips HR, et al. Long-term survival benefits of CABG and percutaneous transluminal angioplasty in patients with coronary artery disease. JTCS;3:5:1013-25. Jelfs P. International Death Index. An important resource for epidemiologist. Australian Institute of Health and Welfare, Canberra.
Simultaneous Coronary Artery Bypass Grafting And Carotid Endarterectomy On Cardiopplmonary Bypass Using Hypothermia M. Matlmr, D. Marshman Royal North Shore Hospital, Sydney, New South Wales attacks and 2 prior strokes. Seven had bilateral carotid stenoses, including 2 with contralateral occlusions. Nine patients had unstable angina, 16 had triple-vessel or left main disease, and 9 had depressed ejection fraction (x0.5). Results: Nineteen patients had a single carotid endarterectomy, and 1 had bilateral carotid endarterectomies. The average number of distals performed was 3.4. The mean bypass time was 108 min and mean aortic cross-clamp time was 77 min, including a mean carotid clamp time of 17 min. There were no postoperative transient or permanent neurological events and no myocardial infarctions. Mortality was zero. Conclusions: Our results suggest that this is a safe, sensible and logical approach to combined CABG surgery and carotid endarterectomy.
Background: Combined coronary revascularisation and carotid endarterectomy is indicated in patients with critical stenoses in both systems. The carotid endarterectomy is usually performed before CPB is instituted. We describe our technique of performing carotid endarterectomy on CPB whilst the aortic crossclamp is applied. Hypothermia and haemodilution are used for cerebral protection. The distal anastomoses are performed during periods of cooling and re-warming, carotid endarterectomy being performed at maximum hypothermia with the aortic cross-clamp applied. Methods: Twenty patients (mean age, 70 years) over a 4year period with symptomatic or asymptomatic carotid stenoses greater than 80% with coexistent significant coronary artery disease, were treated in this way. 14 patients had asymptomatic bruits, 5 transient ischaemic
Histopathology Of The Radial Artery: A Conduit For CABG P. Ruengsakulrach,i
R. Sinclair? I. Gordon?
B. Buxtoni
Department of Cardiac Surgery,1 Department of Pathology ? Austin & Repatriation Medical Centre, and Department of Mathematics and Statistics? University of Melbourne, Victoria Background; The purposes of this study were to determine the histopathology, morphometry and risk factors for development of intimal hyperplasia and atherosclerosis in the radial artery (RA) and to compare the morphometry of the distal and proximal RA. Methods: Segments of RA, obtained from 135 patients who underwent coronary artery surgery, were examined by histopathologp and morphometric analysis. The severity of disease was evaluated by the percentage of luminalnarrowing and the intimal thickness index. Risk factors were determined by stepwise linear and logistic regression. Forty-four paired specimens of distal and
proximal RA were compared morphometrically. Results: The incidence of intimal hyperplasia, atherosclerosis and medial calcification in the distal RAs was 94.1% (127/135), 5.2% (7/135) and 12.6% (17/135), respectively. The majority of the RAs (120/135, 88.9%) had less than 30% luminal narrowing. Factors found to be significant (~~0.05) predictors of intimal hyperplasia in RAs were peripheral vascular disease, smoking, age and diabetes. Medial calcification was only predicted by age. There was no significant difference in the percentage of luminal narrowing in RAs with and without medial calcification. Comparative morphometric analysis
58
Heart J 1999;8(1)
Abstracts Of The Cardiothoracic Section 13th Inter Annual ScientQic Congress. RACS
Myocardial Calcium Control Using A Na+/H+Exchange Inhibitor vs Low Calcium In Cardioplegic Solutions Y. Fukuhiro,
S. Pepe, M. Wowk, R. Ou, F.L. Rosenfeldt
Cardiac Surgical Research Unit, Baker Medical Research Institute and Alfred Hospital, Melbourne, Victoria
Background:
Results: Low Ca++ CP (0.25mM Ca++) significantly
Ca++ overload plays an important role in the pathogenesis of ischaemia/reperfusion injury. The standard technique to control Ca++ overload has been to reduce ionised calcium in the cardioplegic solutions (CP). Recent reports suggest that Na+/H+ exchange inhibitors can also prevent Ca++ overload. We set out to compare 3 crystalloid cardioplegic solutions (CP) which might minimise Ca++ overload in comparison with standard cardioplegia: 1) low Ca++ CP; 2) citrate CP (to reduce ionised Ca++); 3) addition of the Na+/H+ exchange inhibitor HOE642 (HOE). Methods: Isolated working rat hearts perfused with oxygenated KrebsHenseleit buffer were subjected to 60 min of cardioplegic arrest and reperfusion. Aortic flow (AF) was measured before and after ischaemia. Myocardial high energy phosphates were measured after reperfusion.
improved recovery of postischaemic function in comparison with standard CP (1 .OmM Ca++); (%AF: 47.6k1.7 vs 58.3*2.5%, ~~0.05). Citrate CP significantly impaired postischaemic function (%AF: without citrate vs citrate, 58.3k2.5 vs 22.4+6.2%, ~~0.05). Addition of HOE (1 PM) to CP significantly improved postischaemic function (without HOE vs with HOE, 47.6&l .7 vs 62.4+1.7%, ~~0.05). Cardiac high-energy phosphate levels after arrest and reperfusion were significantly reduced by citrate CP. Conclusions: Lowering Ca++ in CP is beneficial. The use of citrate to chelate Ca++ is detrimental in the crystalloid perfused rat heart. HOE in CP is just as efficacious in preserving the myocardium as is directly reducing Ca++.
Coronary Surgery Rationing In New Zealand: Outcome Analysis Of Delaying CABG In Surgical Candidates H.S. Pannu, B.S. Mallya, P.J. Raudkivi, T.M. Agnew, T.L. Whitlock, S. Stone, D.A. Haydock Department of Cardiothoracic Surgery & Cardiology, Green Lane Hospital, Auckland, New Zealand
Background:
In May 1996 the New Zealand Government introduced a coronary scoring system to ration coronary surgery in the public sector. Methods: 130 patients with coronary scores less than 35 were removed from the bypass waiting list (BWL) and put on a 6-monthly review list. We have reviewed the progress of these 130 patients over a 20-month period. Results: 70 patients (53%) have undergone CABG surgery (61 public, 9 private) during follow-up despite being removed from the waiting list. 24 of these 70 CABG
patients presented with acute coronary syndromes (13 with unstable angina and 6 with myocardial infarcts). Eighteen repeat coronary care admissions (in 13 patients) and 15 repeat coronary angiograms (in 14 patients) were necessary before they had CABG procedures. Five patients died: 1 following CABG, 3 sudden deaths and 1 following MI. Conclusions: The N.Z. scoring system fails to ration appropriately when the threshold for entry to surgery is set at 35 points.
Proposed Risk-adjusted National Cardiac Surgical Database B. Buxton,’
F. Rosenfeldt?
J. Smith? J. Fuller 3
Department of Cardiac Surgery, Austin & Repatriation Medical Centre,’ Heidelberg; Baker Medical Research Institute, Alfred Hospital,2 Prahran; Epworth Hospital,3 Richmond, Victoria
Background:
Accurate recordings of death, complications and risk stratification are essential for quality control and for allocation of health resources. Unadjusted mortality and morbidity figures have little or no meaning. Definitions of risk factors and major complications have been a major problem in the past.
The use of the Society of Thoracic Surgeons (STS) definitions has provided uniformity.1 Methods: Major predictors of operative mortality in patients with coronary artery disease have been defined using logistic regression as: age, ventricular function, reoperation and surgical priority.* Less important variables include
57
Asia Pacific
Heart J 1999;8(1)
Abstracts Of The Cardiothoracic Section 13th Inter Annual Scientific Congress, RACS
number of vessels grafted, diabetes, peripheral and cerebral vascular disease, and so on. The proposal is to extract patient identification and important predictive variables from existing hospital databases in Australia. Patient deaths will be matched with a National Death Index (NDI) held at the Australian Institute of Health and Welfare, which records all deaths occurring in Australia since 1980. Death and other outcomes will be analysed and risk adjusted for the major predictive variables. Conclusions: The development of a risk-adjusted national database linked with the ND1 will provide
accurate and important national figures for operative mortality and major complications which may be used for quality control and improvement of standards.3 References 1. 2.
3.
STS on the Web. Definitions of Terms of the Society of Thoracic Surgeons National Cardiac Surgery Database. Jones RH, Kesler K, Phillips HR, et al. Long-term survival benefits of CABG and percutaneous transluminal angioplasty in patients with coronary artery disease. JTCS;3:5:1013-25. Jelfs P. International Death Index. An important resource for epidemiologist. Australian Institute of Health and Welfare, Canberra.
Simultaneous Coronary Artery Bypass Grafting And Carotid Endarterectomy On Cardiopplmonary Bypass Using Hypothermia M. Matlmr, D. Marshman Royal North Shore Hospital, Sydney, New South Wales attacks and 2 prior strokes. Seven had bilateral carotid stenoses, including 2 with contralateral occlusions. Nine patients had unstable angina, 16 had triple-vessel or left main disease, and 9 had depressed ejection fraction (x0.5). Results: Nineteen patients had a single carotid endarterectomy, and 1 had bilateral carotid endarterectomies. The average number of distals performed was 3.4. The mean bypass time was 108 min and mean aortic cross-clamp time was 77 min, including a mean carotid clamp time of 17 min. There were no postoperative transient or permanent neurological events and no myocardial infarctions. Mortality was zero. Conclusions: Our results suggest that this is a safe, sensible and logical approach to combined CABG surgery and carotid endarterectomy.
Background: Combined coronary revascularisation and carotid endarterectomy is indicated in patients with critical stenoses in both systems. The carotid endarterectomy is usually performed before CPB is instituted. We describe our technique of performing carotid endarterectomy on CPB whilst the aortic crossclamp is applied. Hypothermia and haemodilution are used for cerebral protection. The distal anastomoses are performed during periods of cooling and re-warming, carotid endarterectomy being performed at maximum hypothermia with the aortic cross-clamp applied. Methods: Twenty patients (mean age, 70 years) over a 4year period with symptomatic or asymptomatic carotid stenoses greater than 80% with coexistent significant coronary artery disease, were treated in this way. 14 patients had asymptomatic bruits, 5 transient ischaemic
Histopathology Of The Radial Artery: A Conduit For CABG P. Ruengsakulrach,i
R. Sinclair? I. Gordon?
B. Buxtoni
Department of Cardiac Surgery,1 Department of Pathology ? Austin & Repatriation Medical Centre, and Department of Mathematics and Statistics? University of Melbourne, Victoria Background; The purposes of this study were to determine the histopathology, morphometry and risk factors for development of intimal hyperplasia and atherosclerosis in the radial artery (RA) and to compare the morphometry of the distal and proximal RA. Methods: Segments of RA, obtained from 135 patients who underwent coronary artery surgery, were examined by histopathologp and morphometric analysis. The severity of disease was evaluated by the percentage of luminalnarrowing and the intimal thickness index. Risk factors were determined by stepwise linear and logistic regression. Forty-four paired specimens of distal and
proximal RA were compared morphometrically. Results: The incidence of intimal hyperplasia, atherosclerosis and medial calcification in the distal RAs was 94.1% (127/135), 5.2% (7/135) and 12.6% (17/135), respectively. The majority of the RAs (120/135, 88.9%) had less than 30% luminal narrowing. Factors found to be significant (~~0.05) predictors of intimal hyperplasia in RAs were peripheral vascular disease, smoking, age and diabetes. Medial calcification was only predicted by age. There was no significant difference in the percentage of luminal narrowing in RAs with and without medial calcification. Comparative morphometric analysis
58