Reduction in hospitalisation rates following simultaneous carotid endarterectomy and coronary artery bypass grafting; experience from a sing
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《交互式心脏血管和胸部手术》
Department of Vascular Surgery, University Hospital ‘Sestre Milosrdnice’, 10000 Zagreb, Vinogradska 29, Croatia
Abstract
The aim of this study was to compare hospital, clinical, and health care cost among patients undergoing reversed staged procedure coronary artery bypass grafting without cardiopulmonary bypass (off-pump CABG) first and carotid endarterectomy (CEA) second (control group), compared with patients who had simultaneous CEA and off-pump CABG (study group). From January 1, 2000 to December 31, 2004, 53 consecutive patients underwent combined operations at a single institution. Reversed staged procedures were used in the first 23 patients (January 2000–September 2003), and the next 30 patients (September 2003–September 2004) received the one-stage operations. The two groups were similar with respect to baseline characteristics. An internal control system was implemented at the University Clinic Cardiovascular Department (UCCD) in order to compare staged versus simultaneous CEA/OPCABG. The objectives of the internal control system were two-fold: (1) to collect clinical outcomes, resource utilization on patients undergoing reverse-staged or simultaneous OPCABG/CEA and (2) to compare reverse-staged OPCABG/CEA patients, to patients receiving simultaneous CEA/OPCABG in a UCCD. Study patients spent statistically significantly less time in the hospital than control patients (10 vs. 17.9 days). The difference in the mean annual cost of simultaneous versus staged surgery was estimated to be –11.417 Euros (9.619 vs. 21.028 Euros).
Key Words: Coronary artery disease; Carotid occlusive disease; Coronary revascularization; Vascular reconstruction; Hospitalizations; Cost-effectiveness
1. Introduction
Despite significant advances in the pharmacological, carotid and coronary artery angioplasty and stent placement, and surgical management of coronary artery disease (CAD), and concomitant carotid occlusive disease (COD), this remains a condition with exceptionally high rates of morbidity [1–4]. These patients have frequent, lengthy hospitalization. The increasing incidence of concomitant CAD and COD result in significant healthcare costs, with 70% of these attributable to hospital care [5–9]. Simultaneous carotid endarterectomy (CEA) and off-pump coronary artery bypass grafting (OPCABG) show reduced postoperative morbidity and costs. For a population of CAD/COD patients remaining refractory to conventional drug treatment, access to therapies such as simultaneous CEA/OPCABG remains restricted [10,11]. Simultaneously CEA/OPCABG may not generally be indicated in patients with asymptomatic angina following myocardial infarction, with severe ventricular dysfunction (ejection fraction less than 30%), single vessel disease, primary symptoms reflects congestive failure rather than angina, asymptomatic COD [12]. Consequently in these patients postoperative healthcare costs significantly enlarged. To control costs an internal control system for allocation of costs which represent the first step towards total quality management system (TQMS) in a university cardiovascular surgery department was implemented [13–15]. We report results from a single centre, comparing the early and mid-term outcomes for high-risk patients undergoing a reversed-staged versus simultaneous surgical approach for COD/CAD, and examining whether simultaneous (one anesthesia, one hospitalization) versus reverse-staged surgical approach results in clinical improvement in terms of allocation of the resources and hospital costs.
2. Materials and methods
Study approval was obtained from local ethics committee, and written informed consent was obtained from all participants. Patients were reviewed at month 1, and thereafter at 3-monthly intervals post-procedure, with study parameters recorded at each review. For all patients, resource utilization data (e.g. hospital admissions, physician visits, procedures, medications) were collected at baseline, 30 days post-surgery and every three months post-surgery for 1 year. Patient-specific costing information was also obtained from the Croatian Health Organization from initial hospitalization to discharge. The case report forms used to collect the data are presented in Table 1.
This 2-year study includes 53 consecutive patients (44 men and 9 women with mean age of 65.4±5.9 years) who underwent reversed staged and simultaneous CEA/OPCABG at our institution. The first 23 patients (coronary artery revascularization was the primary indication for operation; refused to sign approval for simultaneous surgical approach) had reversed-staged surgical procedure between September 2002 and September 2004, and the following 30 patients underwent a simultaneous surgical procedure between September 14, 2003 and September 30, 2004 (during the same period we have performed 149 isolated CEA – all of first 23 patients underwent CEA; and 66 isolated OPCABG). In all consecutive patients CEA procedures were performed in loco regional anesthesia.
In patients with concomitant coronary and carotid disease (in Croatia there are 8–10% such patients), primary application of stents cannot be recommended even in the unproblematic regions such as the carotid arteries due the high cost of the devices. Our current experiences on not more than 10 patients, in team work with our invasive-radiologists, are in accordance with other centers and outline the same advantages of endovascular treatment. Currently, we are unsure whether there is any evidence to suggest that carotid artery stenting (CAS) is equivalent to the traditional gold standard of CEA and we are not dealing with CAS in this report.
2.1. Patient selection
Study subjects were recruited from consecutive patients admitted to our institution. The simultaneous procedure was the preferred therapeutic approach when the obstructing lesions were equally severe in the two vascular territories and when symptoms (cardiac and neurological) were present.
Inclusion criteria for OPCABG were: NYHA symptom class III or IV; ejection fraction not less than 30%; coronary syndrome needed revascularization; in the previous history no evidence of performed CABG; 6-min hall walk test was 195±114 m prior to surgery; echo cardiogram was documented at baseline and mean left ventricular end diastolic dimension prior to surgery was 6.6±0.2 cm; QRS duratition greater than 130 ms; mean duration of symptom 4.5 years.
Inclusion criteria for CEA were: Color Doppler flow imaging (CDFI) characteristics irrespective of symptoms were: stenosis >70%; ulceration or ulcer thrombosis; thrombosis of the stenotic site; echolucency-gray scale median (GSM) 25–32; soft-core or lipoid plaque; plaque hemorrhage; frayed plaque; the angiographic measurement methods used in the North American Symptomatic Carotid Endarterectomy Trial (NASCET) were used to remeasure carotid stenoses in the European Carotid Surgery Trial (ECST)-qualifying angiograms and to reproduce the stenosis groupings as they were reported for NASCET, because the original ECST method resulted in higher degrees of stenosis than the technique used in NASCET and the Asymptomatic Carotid Atherosclerosis Study (ACAS).
The neurological inclusion criteria were: No disturbances found on four subscales of the Freiburger Personality Inventory (FPI). A transient loss of consciousness in the supine position, preceded by an aura, followed by confusion or amnesia, diplopia, limb weakness, sensory deficits, or speech difficulties.
2.2. Procedure
CEA procedures were done in locoregional anesthesia. The block was performed using bupivacain 0.5%, lidocain 2% with epinephrine 1:200 000. Intraoperatively lidocain 1% with epinephrine or fentanyl intravenously were added when required. Analgetic efficiency was assessed using visual analogue scale (VAS) pre and intraoperatively. Incision and exposure of the carotid bifurcation area. Before clamping heparin (100 IU/kg) was administered. This was followed by carotid endarterectomy, and placement of a patch graft or direct suture depending on which technique was applied, and protamine sulfate was administered to achieve an activated clotting time of 250–300 s. The incision was closed in the usual manner. Then, a routine median sternotomy was performed. The heart was exposed and stabilized with the aid of a retractor and stabilizer. Heparin (100 IU/kg) was administered prior to the start of the first anastomosis to achieve an activated clotting time of 250–300 s. The target coronary vessel was exposed and snared above the anastomotic site using a Gore-Tex suture with a soft plastic snugger to prevent coronary artery injury. The artery was opened, and the distal anastomosis was fashioned. An intracoronary shunt was used with release of the snare to allow distal perfusion. On completion, the proximal anastomoses of vein grafts were performed with partial aortic clamping. On completion of that operation, protamine was given to restore the preoperative value of the activated clotting time.
2.3. Post-procedural care and definitions
Cardiovascular monitoring included the use of a Swan-Ganz pulmonary artery catheter and continuous electrocardiographic monitoring during the first 72 h. Routine standard biochemical and hematological profiles and repeat chest radiographs were also made. Complete perioperative subsystem clinical outcome was recorded. Clinical diagnosis of perioperative MI was confirmed by fulfillment of electrocardiographic and biochemical criteria, and a significant elevation of levels of the myocardial-specific isoenzyme of creatine kinase. Chest infection was defined as the presence of fever with purulent sputum requiring antibiotic therapy.
2.4. Statistical analysis
Data are presented as the mean±standard deviation unless otherwise specified. Paired Student t-tests were used for statistical analysis of the NYHA functional class. Statistical analysis of categorical variables was performed using the 2 or Fisher's exact tests, and continuous data were analyzed with two-sample t-test where appropriate.
3. Results
3.1. Patient population
Baseline and operative characteristics are shown in Tables 2 and 3, respectively.
No differences were observed between groups in regard to mean number of grafts placed and distribution of grafts. In the control group, there were three hospital deaths. One patient died of postoperative low cardiac output syndrome on day 6. Two patients died as a result of multiorgan failure on days 10 and 11. In the study group, one patient died of multiorgan failure. The 30-day mortality rate was 15% and 5% for the control group and study groups, respectively (P=0.25). Postoperative complications are shown in Table 4.
The control group had a significantly higher incidence of cardiac-related events, inotropic support requirement, longer intubation times, and chest infection episodes (all, P<0.05 versus study group). Total blood loss and transfusion requirements were significantly lower in the study group (P<0.001) along with a shorter duration in intensive care unit and hospital stays (P<0.001).
The estimated actuarial 1-year survival rates were 80±9% and 95±5% for the control and study groups, respectively (P=0.13). The 1-year survival rates were 75±10% and 89±8% for the control group and study group, respectively (P=0.22). Details of onset of complications in both groups are listed in Table 5.
Mean NYHA functional class at baseline was 3.3±0.5, which improved to 2.3±0.5 at month 1 (P=0.02). This significant improvement persisted at 3 (2.1±0.3), 6 (2.1±0.3) and 12 months (2.1±0.4).
Distribution of the pre/postoperative level of stroke and cognitive dysfunction showed statistically significant improvements (morbidity 0). Results of CDFI examinations of the internal carotid arteries (ICA) recorded pathologic findings in all patients (COD) and postoperatively in none of study and control group patients.
3.2. Resource utilization and costs
As shown in Table 6, study patients analyzed in this report spent statistically significantly less time in the hospital (10 days) than control group (17.9 days) patients. Length of stay (LOS) in the ICU was also statistically different between study (0.3 days) and control (5.08 days) patients.
As shown in Table 7, in terms of one year resource utilization after the initial hospitalization, control group patients visited specialists more often than study group patients and had more diagnostic tests. Control group patients had significantly more neurological visits than study group patients.
In terms of loss of productivity following CAD/COD repair, the mean number of days taken off work among all employed patients was 45 days (range 0–134). For the purpose of the number of days taken off from work was averaged to all patients and thus the mean paid days off work for the study group was 6.83 days and for the control group 12.2 days. The second measure used to capture productivity losses, the average number of hours of care provided by others, indicates that 14 h (control group) and 19 h (study group) of care were provided by relatives or others. None of these differences were significant across treatment groups. Table 7 also summarizes the utilization of selected resources between both groups.
As shown in Table 8, the total mean 1-year cost with study group patients (Euro 11.417) was statistically lower than the 1-year cost of control group patients.
3.3. Single center evaluation interim cost-effectiveness analysis
Using the preliminary results from the single center evaluation, an incremental cost-effectiveness ratio was calculated to compare reversed-staged versus simultaneous CEA/OPCABG.
Based on the preliminary data collected from these 53 patients, the difference in the mean annual costs was estimated at Euro 1.963 (21.028–9.610). The difference in adjusted QALYs between groups was 0.066 (0.843–0.777). This led to an incremental cost-effectiveness ratio of 29.741 per QALY (1.963/0.066).
It should be noted that the simultaneous CEA/OPCABG cost estimates may be over-estimated due to the higher complication rate and extended length of stay for a few patients.
4. Discussion
The small number of patients for whom one year of follow-up data was available at time of analysis (n=53) limits the generalizability of these results, and comparability of the UCCD experience to other centers. Several limitations associated with this analysis are to be considered when interpreting the results. First, these results are based on a deterministic cost-effectiveness model and the final model must be a fully probabilistic model. Second, not included in this study is an extensive sensitivity analysis around the base case deterministic cost-effectiveness estimates to fully explore the impact of uncertainty on our results. And finally, there is concern over the comparability of simultaneous and staged patients available from the systematic literature review.
Even when the data from all the patients are available and analyzed, it should be emphasized that this single center evaluation is not a randomized controlled trial and there is a potential issue of selection bias as characteristics of patients may be different at time of repair.
An alternative approach for comparing the cost-effectiveness of staged versus simultaneous CEA/OPCABG is to develop a global economic model (ISO 9001–2000) which integrates clinical endpoints and will include an adjustment for base line imbalances between staged and simultaneous CEA/OPCABG patients in the systematic literature review.
Further long-term results from randomized controlled trials comparing simultaneous to staged CEA/OPCABG would be required to confirm our findings.
References
Pullicino P, Halperin J. Combining carotid endarterectomy with coronary bypass surgery: Is it worth the risk. Neurology 2005; 64:1332–1333.
Nakamura Y, Kawachi K, Imagawa H, Hamada Y, Takano S, Tsunooka N, Sakoh M, Kumon Y. Combined carotid endarterectomy and cardiac surgery for concomitant and cardiac disease. Ann Thorac Cardiovasc Surg 2003; 9:180–183.
Zannad F, Briancon S, Juilliere Y, Mertes PM, Villemont JP, Alla F, Virion JM. the EPICAL investigators. Incidence, clinical and etiological features, and outcomes of advanced chronic heart failure: the EPICAL Study. J Am Coll Cardiol 1999; 33:734–742.
Antunes PE, Anacleto G, de Oliveira JM, Eugenio L, Antunes MJ. Staged carotid and coronary surgery for concomitant carotid and coronary artery disease. Eur J Cardiothorac Surg 2002; 21:181–186.
Murray JHW, Rhodes G. An evaulation of the cost of heart failure to the National Health Service in the UK. Br J Med Econ 1993; 6:99–100.
Zacharias A, Schwann TA, Riordan CJ, Clark PM, Martinez B, Durham SJ, Engoren M, Habib RH. Operative and 5-year outcomes of combined carotid and coronary revascularization: review of a large contemporay experience. Ann Thorac Surg 2002; 73:491–497.
Benetis R, Girdauskas E, Kinduris S, Ereminiene E. Combined coronary artery bypass grafting and carotid endarterectomy:early postoperative results and perspectives. Medicina (Kaunas) 2003; 39:390–398.
Reuthebuch O, Lang A, Groscurth P, Lachat M, Turina M, Zund G. Advanced training model for beating heart coronary artery surgery: the Zurich heart-trainer. Eur J Cardiothorac Surg 2002; 22:244–248.
Farooq MM, Reil TD, Gelabert HA, Ahn SS, Baker JD, Moore WS, Quinones-Baldrich WJ, Freischlag JA. Combined carotid endarterectomy and coronary bypass: a decade experience at UCLA. Cardiovasc Surg 2001; 9:339–344.
Naylor AR, Cuffe RL, Rothwell PM, Bell TF. A systematic review of outcomes following staged and synchronous carotid endarterectomy and coronary artery bypass. Eur J Vasc Endovasc Surg 2003; 25:380–389.
Roach GW, Kanchuger M, Mangano CM. Adverse cerebral outcomes after coronary bypass surgery. N Engl J Med 1996; 335:1857–1863.
Roques F, Nashef SA, Michel P, Gauducheau E, de Vincentiis C, Baudet E, Cortina J, David M, Faichney A, Gabrielle F, Gams E, Harjula A, Jones MT, Pintor PP, Salamon R, Thulin L. Risk factors and outcome in European cardiac surgery: analysis of the EuroSCORE multinational database of 19030 patients. Eur J Cardiothorac Surg 1999; 15:816–822.
Beholz S, Konertz W. Improvement in cost effectiveness and customer satisfaction by a quality management system according to EN ISO 9001:2000. Interact CardioVasc Thorac Surg 2005; 4:569–573.
Biflinger TV, Reda H, Giron F, Seifert FC, Ricotta JJ. Coronary and carotid operations under prospective standardized conditions: incidence and outcome. Ann Thorac Surg 2000; 69:1792–1798.
Gaudino M, Glieca F, Luciani N, Cellini C, Morelli M, Spatuzza P, Di Mauro M, Alessandrini F, Possati G. Should severe monolateral asymptomatic carotid artery stenosis be treated at the time of coronary artery bypass operation. Eur J Cardiothorac Surg 2001; 19:619–626.(Narcis Hudorovi)
Abstract
The aim of this study was to compare hospital, clinical, and health care cost among patients undergoing reversed staged procedure coronary artery bypass grafting without cardiopulmonary bypass (off-pump CABG) first and carotid endarterectomy (CEA) second (control group), compared with patients who had simultaneous CEA and off-pump CABG (study group). From January 1, 2000 to December 31, 2004, 53 consecutive patients underwent combined operations at a single institution. Reversed staged procedures were used in the first 23 patients (January 2000–September 2003), and the next 30 patients (September 2003–September 2004) received the one-stage operations. The two groups were similar with respect to baseline characteristics. An internal control system was implemented at the University Clinic Cardiovascular Department (UCCD) in order to compare staged versus simultaneous CEA/OPCABG. The objectives of the internal control system were two-fold: (1) to collect clinical outcomes, resource utilization on patients undergoing reverse-staged or simultaneous OPCABG/CEA and (2) to compare reverse-staged OPCABG/CEA patients, to patients receiving simultaneous CEA/OPCABG in a UCCD. Study patients spent statistically significantly less time in the hospital than control patients (10 vs. 17.9 days). The difference in the mean annual cost of simultaneous versus staged surgery was estimated to be –11.417 Euros (9.619 vs. 21.028 Euros).
Key Words: Coronary artery disease; Carotid occlusive disease; Coronary revascularization; Vascular reconstruction; Hospitalizations; Cost-effectiveness
1. Introduction
Despite significant advances in the pharmacological, carotid and coronary artery angioplasty and stent placement, and surgical management of coronary artery disease (CAD), and concomitant carotid occlusive disease (COD), this remains a condition with exceptionally high rates of morbidity [1–4]. These patients have frequent, lengthy hospitalization. The increasing incidence of concomitant CAD and COD result in significant healthcare costs, with 70% of these attributable to hospital care [5–9]. Simultaneous carotid endarterectomy (CEA) and off-pump coronary artery bypass grafting (OPCABG) show reduced postoperative morbidity and costs. For a population of CAD/COD patients remaining refractory to conventional drug treatment, access to therapies such as simultaneous CEA/OPCABG remains restricted [10,11]. Simultaneously CEA/OPCABG may not generally be indicated in patients with asymptomatic angina following myocardial infarction, with severe ventricular dysfunction (ejection fraction less than 30%), single vessel disease, primary symptoms reflects congestive failure rather than angina, asymptomatic COD [12]. Consequently in these patients postoperative healthcare costs significantly enlarged. To control costs an internal control system for allocation of costs which represent the first step towards total quality management system (TQMS) in a university cardiovascular surgery department was implemented [13–15]. We report results from a single centre, comparing the early and mid-term outcomes for high-risk patients undergoing a reversed-staged versus simultaneous surgical approach for COD/CAD, and examining whether simultaneous (one anesthesia, one hospitalization) versus reverse-staged surgical approach results in clinical improvement in terms of allocation of the resources and hospital costs.
2. Materials and methods
Study approval was obtained from local ethics committee, and written informed consent was obtained from all participants. Patients were reviewed at month 1, and thereafter at 3-monthly intervals post-procedure, with study parameters recorded at each review. For all patients, resource utilization data (e.g. hospital admissions, physician visits, procedures, medications) were collected at baseline, 30 days post-surgery and every three months post-surgery for 1 year. Patient-specific costing information was also obtained from the Croatian Health Organization from initial hospitalization to discharge. The case report forms used to collect the data are presented in Table 1.
This 2-year study includes 53 consecutive patients (44 men and 9 women with mean age of 65.4±5.9 years) who underwent reversed staged and simultaneous CEA/OPCABG at our institution. The first 23 patients (coronary artery revascularization was the primary indication for operation; refused to sign approval for simultaneous surgical approach) had reversed-staged surgical procedure between September 2002 and September 2004, and the following 30 patients underwent a simultaneous surgical procedure between September 14, 2003 and September 30, 2004 (during the same period we have performed 149 isolated CEA – all of first 23 patients underwent CEA; and 66 isolated OPCABG). In all consecutive patients CEA procedures were performed in loco regional anesthesia.
In patients with concomitant coronary and carotid disease (in Croatia there are 8–10% such patients), primary application of stents cannot be recommended even in the unproblematic regions such as the carotid arteries due the high cost of the devices. Our current experiences on not more than 10 patients, in team work with our invasive-radiologists, are in accordance with other centers and outline the same advantages of endovascular treatment. Currently, we are unsure whether there is any evidence to suggest that carotid artery stenting (CAS) is equivalent to the traditional gold standard of CEA and we are not dealing with CAS in this report.
2.1. Patient selection
Study subjects were recruited from consecutive patients admitted to our institution. The simultaneous procedure was the preferred therapeutic approach when the obstructing lesions were equally severe in the two vascular territories and when symptoms (cardiac and neurological) were present.
Inclusion criteria for OPCABG were: NYHA symptom class III or IV; ejection fraction not less than 30%; coronary syndrome needed revascularization; in the previous history no evidence of performed CABG; 6-min hall walk test was 195±114 m prior to surgery; echo cardiogram was documented at baseline and mean left ventricular end diastolic dimension prior to surgery was 6.6±0.2 cm; QRS duratition greater than 130 ms; mean duration of symptom 4.5 years.
Inclusion criteria for CEA were: Color Doppler flow imaging (CDFI) characteristics irrespective of symptoms were: stenosis >70%; ulceration or ulcer thrombosis; thrombosis of the stenotic site; echolucency-gray scale median (GSM) 25–32; soft-core or lipoid plaque; plaque hemorrhage; frayed plaque; the angiographic measurement methods used in the North American Symptomatic Carotid Endarterectomy Trial (NASCET) were used to remeasure carotid stenoses in the European Carotid Surgery Trial (ECST)-qualifying angiograms and to reproduce the stenosis groupings as they were reported for NASCET, because the original ECST method resulted in higher degrees of stenosis than the technique used in NASCET and the Asymptomatic Carotid Atherosclerosis Study (ACAS).
The neurological inclusion criteria were: No disturbances found on four subscales of the Freiburger Personality Inventory (FPI). A transient loss of consciousness in the supine position, preceded by an aura, followed by confusion or amnesia, diplopia, limb weakness, sensory deficits, or speech difficulties.
2.2. Procedure
CEA procedures were done in locoregional anesthesia. The block was performed using bupivacain 0.5%, lidocain 2% with epinephrine 1:200 000. Intraoperatively lidocain 1% with epinephrine or fentanyl intravenously were added when required. Analgetic efficiency was assessed using visual analogue scale (VAS) pre and intraoperatively. Incision and exposure of the carotid bifurcation area. Before clamping heparin (100 IU/kg) was administered. This was followed by carotid endarterectomy, and placement of a patch graft or direct suture depending on which technique was applied, and protamine sulfate was administered to achieve an activated clotting time of 250–300 s. The incision was closed in the usual manner. Then, a routine median sternotomy was performed. The heart was exposed and stabilized with the aid of a retractor and stabilizer. Heparin (100 IU/kg) was administered prior to the start of the first anastomosis to achieve an activated clotting time of 250–300 s. The target coronary vessel was exposed and snared above the anastomotic site using a Gore-Tex suture with a soft plastic snugger to prevent coronary artery injury. The artery was opened, and the distal anastomosis was fashioned. An intracoronary shunt was used with release of the snare to allow distal perfusion. On completion, the proximal anastomoses of vein grafts were performed with partial aortic clamping. On completion of that operation, protamine was given to restore the preoperative value of the activated clotting time.
2.3. Post-procedural care and definitions
Cardiovascular monitoring included the use of a Swan-Ganz pulmonary artery catheter and continuous electrocardiographic monitoring during the first 72 h. Routine standard biochemical and hematological profiles and repeat chest radiographs were also made. Complete perioperative subsystem clinical outcome was recorded. Clinical diagnosis of perioperative MI was confirmed by fulfillment of electrocardiographic and biochemical criteria, and a significant elevation of levels of the myocardial-specific isoenzyme of creatine kinase. Chest infection was defined as the presence of fever with purulent sputum requiring antibiotic therapy.
2.4. Statistical analysis
Data are presented as the mean±standard deviation unless otherwise specified. Paired Student t-tests were used for statistical analysis of the NYHA functional class. Statistical analysis of categorical variables was performed using the 2 or Fisher's exact tests, and continuous data were analyzed with two-sample t-test where appropriate.
3. Results
3.1. Patient population
Baseline and operative characteristics are shown in Tables 2 and 3, respectively.
No differences were observed between groups in regard to mean number of grafts placed and distribution of grafts. In the control group, there were three hospital deaths. One patient died of postoperative low cardiac output syndrome on day 6. Two patients died as a result of multiorgan failure on days 10 and 11. In the study group, one patient died of multiorgan failure. The 30-day mortality rate was 15% and 5% for the control group and study groups, respectively (P=0.25). Postoperative complications are shown in Table 4.
The control group had a significantly higher incidence of cardiac-related events, inotropic support requirement, longer intubation times, and chest infection episodes (all, P<0.05 versus study group). Total blood loss and transfusion requirements were significantly lower in the study group (P<0.001) along with a shorter duration in intensive care unit and hospital stays (P<0.001).
The estimated actuarial 1-year survival rates were 80±9% and 95±5% for the control and study groups, respectively (P=0.13). The 1-year survival rates were 75±10% and 89±8% for the control group and study group, respectively (P=0.22). Details of onset of complications in both groups are listed in Table 5.
Mean NYHA functional class at baseline was 3.3±0.5, which improved to 2.3±0.5 at month 1 (P=0.02). This significant improvement persisted at 3 (2.1±0.3), 6 (2.1±0.3) and 12 months (2.1±0.4).
Distribution of the pre/postoperative level of stroke and cognitive dysfunction showed statistically significant improvements (morbidity 0). Results of CDFI examinations of the internal carotid arteries (ICA) recorded pathologic findings in all patients (COD) and postoperatively in none of study and control group patients.
3.2. Resource utilization and costs
As shown in Table 6, study patients analyzed in this report spent statistically significantly less time in the hospital (10 days) than control group (17.9 days) patients. Length of stay (LOS) in the ICU was also statistically different between study (0.3 days) and control (5.08 days) patients.
As shown in Table 7, in terms of one year resource utilization after the initial hospitalization, control group patients visited specialists more often than study group patients and had more diagnostic tests. Control group patients had significantly more neurological visits than study group patients.
In terms of loss of productivity following CAD/COD repair, the mean number of days taken off work among all employed patients was 45 days (range 0–134). For the purpose of the number of days taken off from work was averaged to all patients and thus the mean paid days off work for the study group was 6.83 days and for the control group 12.2 days. The second measure used to capture productivity losses, the average number of hours of care provided by others, indicates that 14 h (control group) and 19 h (study group) of care were provided by relatives or others. None of these differences were significant across treatment groups. Table 7 also summarizes the utilization of selected resources between both groups.
As shown in Table 8, the total mean 1-year cost with study group patients (Euro 11.417) was statistically lower than the 1-year cost of control group patients.
3.3. Single center evaluation interim cost-effectiveness analysis
Using the preliminary results from the single center evaluation, an incremental cost-effectiveness ratio was calculated to compare reversed-staged versus simultaneous CEA/OPCABG.
Based on the preliminary data collected from these 53 patients, the difference in the mean annual costs was estimated at Euro 1.963 (21.028–9.610). The difference in adjusted QALYs between groups was 0.066 (0.843–0.777). This led to an incremental cost-effectiveness ratio of 29.741 per QALY (1.963/0.066).
It should be noted that the simultaneous CEA/OPCABG cost estimates may be over-estimated due to the higher complication rate and extended length of stay for a few patients.
4. Discussion
The small number of patients for whom one year of follow-up data was available at time of analysis (n=53) limits the generalizability of these results, and comparability of the UCCD experience to other centers. Several limitations associated with this analysis are to be considered when interpreting the results. First, these results are based on a deterministic cost-effectiveness model and the final model must be a fully probabilistic model. Second, not included in this study is an extensive sensitivity analysis around the base case deterministic cost-effectiveness estimates to fully explore the impact of uncertainty on our results. And finally, there is concern over the comparability of simultaneous and staged patients available from the systematic literature review.
Even when the data from all the patients are available and analyzed, it should be emphasized that this single center evaluation is not a randomized controlled trial and there is a potential issue of selection bias as characteristics of patients may be different at time of repair.
An alternative approach for comparing the cost-effectiveness of staged versus simultaneous CEA/OPCABG is to develop a global economic model (ISO 9001–2000) which integrates clinical endpoints and will include an adjustment for base line imbalances between staged and simultaneous CEA/OPCABG patients in the systematic literature review.
Further long-term results from randomized controlled trials comparing simultaneous to staged CEA/OPCABG would be required to confirm our findings.
References
Pullicino P, Halperin J. Combining carotid endarterectomy with coronary bypass surgery: Is it worth the risk. Neurology 2005; 64:1332–1333.
Nakamura Y, Kawachi K, Imagawa H, Hamada Y, Takano S, Tsunooka N, Sakoh M, Kumon Y. Combined carotid endarterectomy and cardiac surgery for concomitant and cardiac disease. Ann Thorac Cardiovasc Surg 2003; 9:180–183.
Zannad F, Briancon S, Juilliere Y, Mertes PM, Villemont JP, Alla F, Virion JM. the EPICAL investigators. Incidence, clinical and etiological features, and outcomes of advanced chronic heart failure: the EPICAL Study. J Am Coll Cardiol 1999; 33:734–742.
Antunes PE, Anacleto G, de Oliveira JM, Eugenio L, Antunes MJ. Staged carotid and coronary surgery for concomitant carotid and coronary artery disease. Eur J Cardiothorac Surg 2002; 21:181–186.
Murray JHW, Rhodes G. An evaulation of the cost of heart failure to the National Health Service in the UK. Br J Med Econ 1993; 6:99–100.
Zacharias A, Schwann TA, Riordan CJ, Clark PM, Martinez B, Durham SJ, Engoren M, Habib RH. Operative and 5-year outcomes of combined carotid and coronary revascularization: review of a large contemporay experience. Ann Thorac Surg 2002; 73:491–497.
Benetis R, Girdauskas E, Kinduris S, Ereminiene E. Combined coronary artery bypass grafting and carotid endarterectomy:early postoperative results and perspectives. Medicina (Kaunas) 2003; 39:390–398.
Reuthebuch O, Lang A, Groscurth P, Lachat M, Turina M, Zund G. Advanced training model for beating heart coronary artery surgery: the Zurich heart-trainer. Eur J Cardiothorac Surg 2002; 22:244–248.
Farooq MM, Reil TD, Gelabert HA, Ahn SS, Baker JD, Moore WS, Quinones-Baldrich WJ, Freischlag JA. Combined carotid endarterectomy and coronary bypass: a decade experience at UCLA. Cardiovasc Surg 2001; 9:339–344.
Naylor AR, Cuffe RL, Rothwell PM, Bell TF. A systematic review of outcomes following staged and synchronous carotid endarterectomy and coronary artery bypass. Eur J Vasc Endovasc Surg 2003; 25:380–389.
Roach GW, Kanchuger M, Mangano CM. Adverse cerebral outcomes after coronary bypass surgery. N Engl J Med 1996; 335:1857–1863.
Roques F, Nashef SA, Michel P, Gauducheau E, de Vincentiis C, Baudet E, Cortina J, David M, Faichney A, Gabrielle F, Gams E, Harjula A, Jones MT, Pintor PP, Salamon R, Thulin L. Risk factors and outcome in European cardiac surgery: analysis of the EuroSCORE multinational database of 19030 patients. Eur J Cardiothorac Surg 1999; 15:816–822.
Beholz S, Konertz W. Improvement in cost effectiveness and customer satisfaction by a quality management system according to EN ISO 9001:2000. Interact CardioVasc Thorac Surg 2005; 4:569–573.
Biflinger TV, Reda H, Giron F, Seifert FC, Ricotta JJ. Coronary and carotid operations under prospective standardized conditions: incidence and outcome. Ann Thorac Surg 2000; 69:1792–1798.
Gaudino M, Glieca F, Luciani N, Cellini C, Morelli M, Spatuzza P, Di Mauro M, Alessandrini F, Possati G. Should severe monolateral asymptomatic carotid artery stenosis be treated at the time of coronary artery bypass operation. Eur J Cardiothorac Surg 2001; 19:619–626.(Narcis Hudorovi)