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OUTCOMES OF OFF-PUMP VERSUS ON-PUMP CORONARY ARTERY BYPASS GRAFTING FOR ISCHEMIC HEART DISEASE IN PATIENTS OVER SEVENTY YEARS OF AGE.

Byline: Nasir Ali Khan, Muhammad Waseem, Fida Hussain and Safdar Ali Khan

ABSTRACT

Objective: To evaluate the perioperative characteristics and short term surgical outcomes of off-pump versus on-pump CABG in elderly patients above the age of 70 years with ischemic heart disease.

Study Design: Descriptive cross-sectional study

Place and Duration of Study: This study was conducted at Army Cardiac Centre Lahore from January 2014 to December 2015.

Material and Methods: A total of 129 patients according to inclusion criteria above 70 years of age were included in the study. Patients with combined procedures (CABG with valve repair/ replacement) were excluded from the study. Operative risk of all patients was assessed as per the European System for Cardiac Operative Risk Evaluation (EuroSCORE).

Results: There were 53 patients in the OPCAB group and 76 patients in the CCAB group. The OPCAB group had 6 (11.3%) females and 47 (88.6%) males whereas in CCAB group there were 7 (9.2%) females and 69 (90.7%) males. IABP was used only in CCAB group 12 (15.8%). As regards short term outcomes the OPCAB group had mean extubation time of 228 +- 188.80 min as compared to CCAB group with a mean extubation time of 395.1 +- 489.7 min p value 0.001. Mean length of stay observed in OPCAB group was shorter 3.65 +- 2.63 days against CCAB group 6.5 +- 6.9 days p value 0.01.

Conclusion: Off-pump (OPCAB) coronary artery bypass was associated with reduced adverse events compared with on-pump (CCAB) coronary artery bypass in patients aged >70 years with a trend towards better early survival.

Keywords: Off pump coronary artery bypass grafting, on pump coronary artery bypass grafting, length of stay.

INTRODUCTION

Coronary artery bypass grafting (CABG) is effective at reducing angina and improving survival in appropriate patients with coronary artery disease. With increasing old population and subjecting those to angiographic procedures bring more cases for surgical coronary revascularization. Although majority of the CABG procedures are performed on the arrested heart with the support of cardiopulmonary bypass CPB and the off pump technique performed on the beating heart have been developed in an attempt to avoid neurocognitive and other complications like thought to be associated with cardiopulmonary bypass1. High risk patients including elderly are particularly susceptible to damage initiated by CPB2.

Off Pump Coronary Artery Bypass (OPCAB) as opposed to Conventional Coronary Artery Bypass (CCAB) is associated with short-term and long-term benefits in stroke prevention, atrial fibrillation, wound infection, acute kidney injury in patients at higher risk including the elderly as estimated by European System for Cardiac Risk Evaluation (EuroSCORE)3,5. The ROOBY trial documented insignificant difference between off pump and on pump CABG surgery in the primary short term end points of death or major complications at 30 days4.

MATERIAL AND METHODS

A descriptive cross sectional study was conducted at Army Cardiac Centre Lahore from 2014 to 2015. The study was approved by the institutional ethical review board. All the data were collected prospectively at the time of operation and entered into a database. A total of 129 patients according to inclusion criteria above 70 years of age were included in the study after informed written consent. Patients with combined procedures (CABG with valve repair/ replacement) were excluded from the study. Operative risk of all patients was assessed as per the European System for Cardiac Operative Risk Evaluation (EuroSCORE). All procedures were done through a median sternotomy incision. Left internal mammary artery (LIMA) was used as a conduit in all patients unless contraindicated. A segment of saphenous vein was used as a conduit when required.

OPCAB procedures were conducted with an activated clotting time (ACT) maintained above 300 seconds. The required vessels were exposed with the help of swabs placed under the heart and deep pericardial retraction sutures to lift the heart. Hemodynamic instability resulting from displacement of the heart during OPCAB was managed actively by the anesthetist with a combination of positioning of the operation table, intravenous fluids and pharmacotherapy. After optimal exposure and stabilization with a suction based stabilizer system Octopus 4.3 or Evolution (Medtronic,MN,USA the target vessel was opened. An appropriately sized intra-coronary shunt was placed to maintain perfusion of the dependent myocardium and distal anastomosis performed using 7/0 or 8/0 Prolene (Ethicon JandJ, OH,USA) suture. Proximal anastomosis was achieved using a partial occluding vascular clamp on the ascending aorta, an aortotomy punch and 6/0 or 7/0 Prolene.

The left anterior descending (LAD) artery was grafted first in most cases followed by diagonal, right coronary artery and then finally the obtuse marginal. In patients with severe coronary disease and depressed left ventricular function, proximal anastomosis of a graft was constructed prior to distal anastomosis to achieve 'functional revascularization'.

Conventional CABG was carried out with the use of CPB and an ACT maintained above 500 seconds. Cardiac arrest and myocardial protection strategies employed differed with the operating surgeons' preference. Blood based cardioplegic solution was delivered either antegrade in the aortic root, or, antegrade as well as retrograde through a cannula placed in the coronary sinus. After aortic cross clamp and arrest of the heart, all distal anastomoses were completed first. Inotropic support and intra-aortic balloon pump (IABP) was used during the weaning off process whenever required. Heparin was reversed with protamine in 1:1 ratio at the conclusion of the operation. All the patient were managed and strictly monitored postoperatively similarly in both groups. They were kept on mechanical ventilation till complete cardiorespiratory and neurological recovery.

RESULTS

A total number of 129 patients above the age of 70 years were included in the study. There were 53 patients in the OPCAB group and 76 patients in the CCAB group. The OPCAB group had 6 (11.3%) females and 47 (88.6%) males whereas in CCAB group there were 7 (9.2%) females and 69 (90.7%) males. The distribution of age in OPCAB group was 70.2 (range 70-80 yrs) as opposed to CCAB group 76 yrs (range 70-85 yrs).

The CCAB group had more number of smokers 19 (25%), and hypertensive patients 37 (48.7%) versus OPCAB group 13(24.5%) and 19(25%). The mean ejection fraction in OPCAB group was 50.7% +- 10.27 whereas CCAB group had a lower mean EF 47.4% +- 15.56.

IABP was used only in CCAB group 12 (15.8%). As regards short term outcomes the OPCAB group had mean extubation time of 228 +- 188.80 min as compared to CCAB group with a mean extubation time of 395.1 +- 489.7 min p value 0.001. Mean length of stay observed in OPCAB group was shorter 3.65 +- 2.63 days against CCAB group 6.5 +- 6.9 days p value 0.01.

Table-1: Demographic, Clinical, per and post-operative characteristics of group A and group B

Sr. ####Variables###Group A (Off pump) n = 53###Group B (On pump) n = 76###p value

###Demographic Characteristics

1.###Age (mean, range) years###70.2, 70-80###76.0, 70-85###0.5

2.###Gender###n(%)

###Males###47 (88.6%)###69 (90.7%)###0.55

###Females###6 (11.3%)###7 (9.2%)###0.42

3.###Weight (mean +- SD) kg###70.03 +- 1.19###74.87 +- 1.41###0.7

###Clinical Characteristics

4.###Co-morbids

###Hypertension###34 (64.2%)###37 (48.7%)###0.6

###Diabetes Mellitus###18 (34%)###18 (23.7%)###0.9

5.###Smokers###13 (24.5%)###19 (25%)###0.6

6.###Euro SCORE###6.2 +- 2.04###4.12 +- 2.51###0.1

7.###CCS class###2.16 +- 0.37###2.05 +- 0.63###0.8

8.###NYHA class (mean +- SD)###2.15 +- 0.41###1.98 +- 0.68###0.61

9.###LV ejection fraction (mean +- SD)###50.73 +- 10.27###47.48 +- 15.56###0.42

10.###Poor LV function n(%)###5 (9.4%)###5 (6.6%)###0.65

###Per-Operative Parameters

11.###Lima graft n (%)###40###65 (85%)###0.5

12.###Vein graft (mean+- SD)###2.15 +- 0.93###2.21 +- 1.09###0.8

13.###Antegrade cardioplegia n (%)###-###60 (78.9%)

14.###Ante and retrograde cardioplegia n (%)###-###16 (21.1%)

15.###Endarterectomy n(%)###-###4 (5.3%)

16.###Bypass time (mins) (mean+- SD)###-###112.05 +- 53.09

17.###Cross clamp time (mins) (mean+- SD)###-###65.37 +- 36.60

18.###IABP n (%)###-###12 (15.8%)

###Post operative parameters

19.###Extubation time (mean+- SD) mins###228.6 +- 188.80###395.19 +- 489.75###0.001

20.###Length of stay (mean+- SD) days###3.65 +- 2.63###6.5 +- 6.9###0.01

21.###Fever n (%)###5 (17%)###15(27.6%)###0.02

22.###Sternal Infections n (%)###5 (17%)###0 (0%)###0.006

23.###Re opening n (%)###4 (7.5%)###21(14.5%)###0.001

24.###Dialysis n (%)###1 (1.9%)###4(5.3%)###0.06

25.###Mortality n (%)###(5.7%)###8(10.5%)###0.03

26.###Stroke###0 (0%)###5 (6.57%)###0.01

The number of post-operative mediastinal exploration was relatively higher in CCAB group 21 (14.5%) versus OPCAB group 4 (7.5%) p value 0.001. However, the incidence of surgical site infections was higher in OPCAB group 5 (17%) p value 0.006. A trend toward higher postoperative mortality was observed after CCAB 8 (10.5%) opposed to OPCAB group 3 (5.7%) p value 0.03.

DISCUSSION

Although OPCAB surgery is regarded as a recent advancement in the treatment of ischemic heart disease, but history suggests the initial surgical procedures were performed on beating heart6. Favalaro popularized the coronary artery bypass with saphenous vein grafts using heart lung machine in late sixties7. With the advancement of perfusion technology and myocardial protection techniques, most of the surgeons preferred on-pump surgery with a still heart and blood less field. During cardiopulmonary bypass blood is exposed to synthetic surfaces and shear forces of the pump leading to a whole body inflammatory response which can have potential deleterious effects of varying degrees leading to dysfunction of brain, lungs, kidneys and heart2,3. Embolization of air, particulate matter from atherosclerotic aorta, heart or bypass circuit is another source of complications.

Age is an independent risk factor in patients undergoing coronary artery bypass surgery. Various authors have documented that the off-pump bypass is beneficial in elderly patients and patients with high comorbid conditions7. The elderly patients not only carry comorbidities but also have severe coronary artery disease8. With advances in interventional cardiology there has been drop in potential candidates for isolated coronary artery bypass surgery resulting in shift for high risk cases for bypass surgery. Avoiding cardiopulmonary bypass can be beneficial in this group as the side effects of the pump as well metabolic stress are avoided. It is well known that elderly are particularly susceptible to effects of inflammatory mediators. Most of the published papers reported similar in hospital mortality for CCAB and OPCAB procedures9. However some recent non randomized studies have shown that mortality is higher in patients operated on cardiopulmonary bypass.

In our study, the mortality in the off-pump group was 5.7% and in on-pump group it was 10.5%. All patients in group A were with EoroSCORE >5 with age more than 70, implying a higher risk group. The mortality was 70 years with a trend towards better early survival. However, suboptimal quality of the available studies, particularly the lack of comparability of the study groups, prevents conclusive results on this controversial issue.

CONFLICT OF INTEREST

This study has no conflict of interest to declare by any author.

REFERENCES

1. S.G Raja and G.A Berg, "Impact of off pump coronary artery bypass surgery on systemic inflammation: current best available evidence. Journal of Cardiac Surgery 2007; Vol.22, no.55, 455-455.

2. Selnes OA, Gottesman RF, Grega MA, Baumgartner WA, Zeger SL, McKhann GM. Cognitive and neurologic outcomes after coronary-artery bypass surgery. N Engl J Med 2012;366:250-7.

3. Diegeler A, Doll N, Rauch T, et al. Humoral immune response during coronary bypass grafting: a comparison of limited approach, "off-pump" technique, and conventional cardiopulmonary bypass. Circulation 2000; 102: Suppl 3: III-95-III-100.

4. Shroyer AL, Grover FL, Hattler B, et al. On-pump versus off-pump coronary artery bypass surgery for the Veterans Affairs Randomized On/Off Bypass (ROOBY) Study Group. N Engl J Med 2009; 361:1827-37.

5. Roques F, Michel P, Goldstone AR, Nashef SAM. The logistic EuroSCORE. Eur Heart J 2003; 24:881-2.

6. Vineberg A. Coronary vascular anastomosis by internal mammary artery implantation. Can Med Assoc J 1958; 78:871-9.

7. Favalaro RG. Saphenous vein autograft replacement of severe segmental coronary artery occlusion: operative technique. Ann Thorac Surg 1968;5: 334-9.

8. Hoff SJ, Ball SK, Coltharp WH, Glassford DM Jr, Lea JW IV, Petracek MR. Coronary artery bypass inpatients 80 years and over: is off-pump the operation of choice? Ann Thorac Surg. 2002; 74:S1340-S1343.

9. Hirose H, Amano A, Takahashi A. Off-pump coronary artery bypass grafting for elderly patients. Ann Thorac Surg. 2001; 72:2013-2019.

10. Houlind K, Kjeldsen BJ, Madsen SN, Rasmussen BS, Holme SJ, Schmidt TA, Haahr PE, Mortensen PE; DOORS Study group. The impact of avoiding cardiopulmonary by-pass during coronary artery bypass surgery in elderly patients: the Danish On-Pump Off-Pump Randomization Study (DOORS). Trials. 2009; 10:47-56.

11. Demaria RG, Carrier M, Fortier S, Martineau R, Fortier A, Cartier R, Pellerin M, He'bert Y, Bouchard D, Page' P, Perrault LP. Reduced mortality and strokes with off-pump coronary artery bypass grafting surgery in octogenarians. Circulation. 2002; 106:I5-I10.

12. Stamou SC, Dangas G, Dullum MK, Pfister AJ, Boyce SW, Bafi AS, Garcia JM, Corso PJ. Beating heart surgery in octogenarians: perioperative outcome and comparison with younger age groups. Ann Thorac Surg. 2000; 69: 1140-1145.

13. Athanasiou T, Al-Ruzzeh S, Kumar P, Crossman MC, Amrani M, Pepper JR, Del Stanbridge R, Casula R, Glenville B. Off-pump myocardial revascularization is associated with less incidence of stroke in elderly patients. Ann Thorac Surg. 2004; 77: 745-753.

14. Al-Ruzzeh S, George S, Yacoub M, Amrani M. The clinical outcome of off-pump coronary artery bypass surgery in the elderly patients. Eur J Cardiothorac Surg. 2001;20: 1152-1156.

15. Hattler B, Messenger JC, Shroyer AL, et al. Off-pump coronary artery bypass surgery is associated with worse arterial and saphenous vein graft patency and less effective revascularization: results from the Veterans Affairs Randomized On/Off Bypass (ROOBY) trial. Circulation 2012; 125:2827-35. A. Parolari, F. Alamanni, A. Cannata et al., "Off-pump versus on-pump coronary artery bypass: meta-analysis of currently available randomized trials,

16. "Annals of Thoracic Surgery, vol.76, no.1, pp.37-40, 2003.

17. J. T. Reston, S. J. Tregear, and C. M. Turkelson, "Meta-analysis of short-term and mid-term outcomes following off-pump coronary artery bypass grafting," Annals of Thoracic Surgery, vol. 76, no.5,pp.1510-1515,2003.

18. Lamy A, Devereaux PJ, Prabhakaran D, et al. Off-pump or on-pump coronary artery bypass grafting at 30 days. N Engl J Med 2012;366:1489-97.

19. Moller CH, Perko MJ, Lund JT, et al. No major differences in 30-day outcomes in high-risk patients randomized to off pump versus on-pump coronary bypass surgery: the Best Bypass Surgery Trial. Circulation 2010;121:498-504.

20. Sedrakyan A, Wu AW, Parashar A, Bass EB, Treasure T. Off-pump surgery is associated with reduced occurrence of stroke and other morbidity as compared with traditional coronary artery bypass grafting: a meta-analysis of systematically reviewed trials. Stroke. 2006; 37: 2759-2769.

21. Nathoe HM, Moons KG, van Dijk D, Jansen EW, Suyker WJ, Stella PR, Lahpor JR, van Boven WJ, van Dijk D, Diephuis JC, Borst C. Risk and determinants of myocardial injury during off-pump coronary artery bypass grafting. Am J Cardiol. 2006; 97:1482-1486.

22. Puskas JD, Williams WH, Duke PG, Staples JR, Glas KE, Marshall JJ, Leimbach M, Huber P, Garas S, Sammons BH, McCall SA, Petersen RJ, Bailey DE, Chu H, Mahoney EM, Weintraub WS, Guyton RA. Off-pump coronary artery bypass grafting provides complete revascularization with reduced myocardial injury, transfusion requirements, and length of stay: a prospective randomized comparison of two hundred unselected patients undergoing off-pump versus conventional coronary artery bypass grafting. J Thorac Cardiovasc Surg. 2003; 125:797-808.

23. Maitra G, Ahmed A, Rudra A, et al. Renal dysfunction after off pump coronary artery bypass surgery-risk factors and preventive strategies. Indian J Anaesth 2009; 53: 401-7.

24. Raja SG, Dreyfus GD. Impact of off-pump coronary artery bypass surgery on postoperative renal dysfunction: current best available evidence. Nephrology (Carlton) 2006; 11: 269-73. 21.

25. Weerasinghe A, Athanasiou T, Al-Ruzzeh S, et al. Functional renal outcome in on-pump and off-pump coronary revascularization: a propensity-based analysis. Ann Thorac Surg 2005; 79: 1577-1583.
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Publication:Pakistan Armed Forces Medical Journal
Article Type:Report
Date:Apr 30, 2016
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