|Year : 2019 | Volume
| Issue : 4 | Page : 1323-1327
Short-term outcomes of emergency coronary artery bypass grafting
Abouelmakarem M Abdelmoaty1, Ahmed L Dokhan2, Aly H Taher1, Medhat R Nashy2
1 Department of Cardiothoracic Surgery, Faculty of Medicine, Menoufia University, Menoufia, Egypt
2 Department of Cardiac Surgery, National Heart Institute, Giza, Egypt
|Date of Submission||19-Aug-2018|
|Date of Decision||01-Oct-2018|
|Date of Acceptance||09-Oct-2018|
|Date of Web Publication||31-Dec-2019|
Abouelmakarem M Abdelmoaty
Yousef Bin Hammoud Street, Salmyia, Kuwait City 20002
Source of Support: None, Conflict of Interest: None
This study aims to evaluate short-term outcomes of emergency coronary artery bypass grafting (CABG) surgery, about inotropic support, complications, and early postoperative morbidity and mortality.
Outcomes of emergency CABG surgery for critical left main coronary artery disease.
Patients and methods
Forty patients were examined from October 2013 to May 2018. Those included were those who underwent emergency CABG; patients with left main coronary artery disease more than 90% or left main equivalent more than 90%,; and all patients undergoing coronary artery bypass surgery.
Most of our patients had severe chest pain before surgery. Sixteen (40%) patients showed severe chest pain in one or two steps. Fourteen (35%) patients show severe pain during rest, Hemo-dynamic (HD) instability (32.5%), need for inotropes (32.5%), need for intra-aortic balloon pump counterpulsation (67.5%), postoperative bleeding (7.5%), arrhythmia (10%), myocardial infarction (2.5%), renal impairment (2.5%), stroke (2.5%), and in hospital postoperative mortality (2.5%).
The study shows a statistically significant difference in the improvement of ejection fraction% in the study group through the whole period of study with a P value of 0.047.
Our study demonstrated that the patients undergoing emergency CABG have a significant higher preoperative risk especially with myocardial impairment. A reasonable and favorable clinical outcome can be achieved when those patients tolerate the surgery and survive. Also, we assume that establishing hemodynamic stability in conjunction with the cardiologist prior to surgery significantly influences the surgical outcome.
Keywords: acute myocardial infarction, coronary artery bypass grafting, emergency coronary artery bypass grafting, left main coronary artery, left main equivalent
|How to cite this article:|
Abdelmoaty AM, Dokhan AL, Taher AH, Nashy MR. Short-term outcomes of emergency coronary artery bypass grafting. Menoufia Med J 2019;32:1323-7
|How to cite this URL:|
Abdelmoaty AM, Dokhan AL, Taher AH, Nashy MR. Short-term outcomes of emergency coronary artery bypass grafting. Menoufia Med J [serial online] 2019 [cited 2020 Jun 6];32:1323-7. Available from: http://www.mmj.eg.net/text.asp?2019/32/4/1323/274246
| Introduction|| |
Acute occlusion of the left main coronary artery (LMCA) is a rare but serious condition, which carries a very high mortality rate due to massive acute myocardial infarction (AMI). Most of these patients with this clinical setting may suffer from sudden death or profound cardiogenic shock due to malignant arrhythmia or pump failure .
Although uncommon, LMCAD is a constant topic of discussion between cardiac surgeons and interventional cardiologists. This discussion began in 1975, when Gorlin and Cohen first compared a surgical approach for Left main coronary artery (LM) stenosis to any other treatment options and reported that coronary artery bypass grafting (CABG) showed significant benefits over medical therapy in the treatment of LMCAD .
Definition of emergency CABG according to most of literatures is the procedure required immediately in the first 24 h after hospitalization to minimize the chance of further clinical deterioration. Examples include but are not limited to: worsening HD, sudden chest pain, anatomy, intra-aortic balloon pump (IABP), unstable angina with intravenous nitroglycerin or rest angina, congestive heart failure, and AMI .
The NOBLE and EXCEL trials examined the role of CABG versus percutaneous coronary intervention (PCI) in LMCAD and had discordant findings with the NOBLE trial demonstrating superiority with surgery and the EXCEL trial demonstrating noninferiority of PCI. While the NOBLE trial had a longer follow-up, the overall follow-up time in both trials was relatively short. At best, PCI can be considered in LMCAD either in patients who are not surgical candidates or potentially in high-risk patients with low SYNTAX scores. The optimal revascularization strategy for LMCAD will continue to be an issue of investigation in the future, and the results of long-term follow-up must be sought after and carefully examined to best assess the true comparative effectiveness of CABG versus PCI in patients with LMCAD .
This study aims to evaluate short-term outcomes of emergency CABG surgery. It also dealt with inotropes, problems, and early postoperative results.
| Patients and Methods|| |
This study was approved by the Ethics Committee. This prospective study was conducted on 40 patients in Menoufia Faculty of Medicine and National Heart Institute from 2013 to 2018. Informed consent was taken from each patient. All patients had critical LMCAD more than 90% or left main equivalent more than 90%, which is hemodynamically stable or hemodynamically unstable and is irresponsive to intense medical treatment. The patients were listed for CABG. They were deemed to be at high surgical risk based on risk profiling after calculating the European System for Cardiac Operative Risk (Euro SCORE). All patients underwent coronary artery bypass surgery via full median sternotomy, harvesting of left internal mammary artery (LIMA) with long saphenous vein harvesting and full bypass with single aortic cross-clamping and interpreted warm antegrade blood cardioplegia.
Exclusion criteria were redo CABG, combined other lesions as valvular lesions, left ventricular aneurysm, ventricular septal rupture, dissection or perforation of coronaries, and ejection fraction (EF) less than 30%. Those with severe decompensated liver, respiratory disease, and chronic renal failure were also excluded.
Patient's medical history including age, sex, New York Heart Association classification, and preoperative risk factors were recorded. Echocardiography was done for all patients and assessment was done for all patients before surgery, on discharge, and 6 months after. Intraoperative data: total cardiopulmonary bypass (CPB) time, cross-clamp time, myocardial protection, number of distal anastomoses; postoperative data: use of inotropic support, insertion of IABP, duration of mechanical ventilation, ICU stay, postoperative complication (hemorrhage, reopening, infection, etc.), postoperative echocardiography, wards stay, and in-hospital morbidity and mortality.
Overall mortality during hospital stay from the intervention was the primary endpoint. Secondary endpoints included overall mortality within 6 months and the incidence of postoperative bleeding which require reopening, postoperative myocardial infarction, defined as CK-MB that exceeds five times the upper normal limit with or without new Q waves, stroke, defined as any new persistent neurological deficit and postoperative arrhythmia.
The data were collected, tabulated, and statistically analyzed by using the statistical package for the social sciences, version 20.0 (SPSS statistics, Version 20.0; IBM Corp., Armonk, New York, USA). Quantitative data were expressed as mean ± SD. Qualitative data were expressed as frequency and percentage, the following tests were done: independent-samples t test of significance was used when comparing between two means. χ2 test of significance was used to compare proportions between two qualitative parameters. P value less than or equal to 0.05 was considered significant. P value less than or equal to 0.001 was considered as highly significant. P value more than 0.05 was considered insignificant.
| Results|| |
Baseline characteristics, mean patients' age was 52.21 ± 7.19, 25 (63.3%) patients were men and 15 (36.7%) were women [Table 1].
Procedural data mean CPB time 107.3 ± 26.6 and clamp time (AXC) 79.4 ± 26.1, cardioplegia type: warm antegrade blood cardioplegia in all studied patients. We examined 40 patients, eight patients had two (20%) distal anastomoses of the study group, 21 patients had three (21%) distal anastomoses, and 11 patients had four distal anastomoses, 27.5% of the study group. All patients had LIMA and saphenous vein graft; only six patients had radial artery graft who were hemodynamically stable preoperatively [Table 2].
Clinical outcomes and postoperative follow-up data: use of the inotropes postoperatively (40%), IABP postoperatively (67.5%), postoperative bleeding (7.5%); seven patients showed postoperative arrhythmias, 10% of all cases; in two patients who had postoperative atrial fibrillation cordarone infusion started as a loading and then maintained and subsided predischarge without starting warfarin, one patient had supraventricular tachycardia without hemodynamic instability, and one patient had persistent ventricular fibrillation and died during the ICU stay.; MI (2.5%), renal impairment (2.5%), stroke (2.5%), and in-hospital postoperative mortality (2.5%) were monitored. Mean ventilation time was (6–120 h) 8.87 ± 52 and ICU stay time was (3–10 days) 5.69 ± 27 [Table 3].
Echocardiographic outcomes: we lost 1/40 of our patient population representing about 2.5% mortality; 39 patients were discharged free of symptoms with a predischarge ECHO measurement of their EFs as follows: for group A 17 patients had initial EF 50–60%, one patient had transient decrease of EF to become between 40 and 49%, at predischarge ECHO; however, at 6 months ECHO follow-up 21 patients were between 50 and 60%, 16 between 40 and 49%, and another two between 30 and 39%; of the 12 group B patients, initial EF 40–49%, one had an increase of EF to 50–60%, 10 remained same as preoperative EF, and one decreased to 30–39% and at 6 months follow-up all 12 patients remained at 40–49% while two patients improved to 50–60%; for group C 11 patients had an initial EF of 30–39%, one patient's EF increased to 50–60%, two increased to 40–49% while eight remained at EF 30 = 39% and one patient died in the ICU, at 6 months follow-up, one patient increased to EF 50–60%, five patients improved EF to 40–49%, and only two patients remained at EF 30–39%. This finding was statistically significant (P = 0.047) [Table 4].
|Table 4: Improvement in ejection fraction over the whole period of study|
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| Discussion|| |
The synergy between PCI and cardiac surgery (SYNTAX) trial supported the use of CABG as the standard of care for patients with high or intermediate SYNTAX scores due to lower rates of major adverse cardiac and cerebrovascular events, myocardial infarction, and repeat revascularization when compared with PCI in patients with mild disease or a lower SYNTAX score .
In the NOBEL trial, the authors demonstrated that major adverse cardiac events occurred with a frequency of 19% in the CABG group (81 events) in comparison to 29% in the PCI group (121 events).
CABG was concluded to be superior to PCI (P = 0.0066). At 5 years follow-up, CABG had an all-cause mortality of 9 versus 12% in the PCI group (1.07, 0.6–1.72, P = 0.77), 2 versus 7% (2.88, 1.40–5.90, P = 0.0040) for nonprocedural myocardial infarction, 10 versus 16% (1.50, 1.04–2.17, P = 0.02) for any revascularization, and 2 versus 5% (2.25, 0.93–5.48, P = 0.073) for stroke .
In our study, there are nine patients who showed preoperative MI (22.5%). Rastan et al.  reported 28% with 21.7%, Kim et al.  stated that 24% showed recent MI and it was a reason to postpone surgery 3 days till the level of troponin comes down and bypass the AMI phase.
In our study, cholesterol levels above 200 mg/ml were considered as hyperlipidemia; A total of 25 (65%) patients showed hyperlipidemia out of 40 patients same Rastan et al.  reported 77% showed hyperlipidemia.
In our study postoperative renal dysfunction occurred in one case which represents 2.5% of our cases, while Kim et al.  showed that postoperative renal dysfunction occurs in as many as 7.7% of patients.
Renal dysfunction, defined as postoperative serum creatinine level of at least 2.0 mg/dl, was accompanied by an increase of at least 0.7 mg/dl from the preoperative baseline.
The use of preoperative IABP in our study was in 27/40 (67.5%%) patients while with other authors like Hata et al. , all his cases had IABP before surgery. while Kim et al. , when he reviewed 104 patients with urgent CABG he found that 31 (29.8%) patients need preoperative IABP insertion, in the same line Christenson et al.  reported preoperative insertion of IABP in five (28%) of his patient who needed emergency CABG, and concluded that the beneficial effect of preoperative IABP in high-risk patients who have CABG was confirmed. Therefore, at 2 h preoperatively, IABP therapy can be started.
The main indication of emergency in our study is intractable chest pain in 17 (43%) who required intravenous nitroglycerine, and critical left main more than 90% in 23 (57.5%) patients with or without hemodynamic instability.
In our study, the LMCAD represented 34 (85%) and LM equivalent six (15%) while Kim et al.  stated that 35.6% had left main coronary stenosis and 64.4% had left main equivalent. In Rastan et al.  46% of the cases LMCAD.
In our group all patients had LIMA and saphenous vein graft, only six patients had radial artery graft, 52.5% of patients underwent CABG with three grafts while 27.5% with four grafts and 20% with two grafts. Bypass time (CPB) was 59–213 (107.3 ± 26.6), cross-clamp time (AXC) was 41–170 (79.4 ± 26.1), while Rastan et al.  stated that the mean number of arterial graft 1.3 ± 0.7 arterial graft with 99.7% use of LIMA, and Hata et al.  had a CPB time of 132.8 ± 38, AXC time 73.1 ± 20.1, the same clamp time but he had longer bypass time.
The mean chest tube drainage in our study is 1451 ± 507.6; the packed red blood cells transfused is 2.58 ± 1.91 U, fresh frozen plasma transfusion is 4.92 ± 3.57 U, and platelet transfusion is 3.74 ± 3.79 U. This usually is attributed to that emergency patients going for CABG were on clopidogrel till few days preoperatively. Many of them was on heparin or intravenous antiplatelet therapy. On the same line Rastan et al.  reported the mean tube drainage 1650 ml with packed red blood cell transfused being about 2.5 U.
We found that seven patients showed postoperative arrhythmias in 10% of cases, two patients had postoperative atrial fibrillation had cordarone infusion started as a loading and then maintained and subsided predischarge without starting warfarin; one patient had supraventricular tachycardia without HD instability, and one patient with persistent ventricular fibrillation died during the ICU stay, while Rastan et al.  reported 30.2% postoperative arrhythmias.
We observed a long ventilation time mean of 8.87 ± 52 which ranged from 6 to 120 h. Chen et al.  reported longer ventilation hours, mean 16 h with a range of 8–695 h and Rastan et al.  reported longer ventilation hours mean of 13.5% which ranged from 5 to 90 h.
ICU stay time was (3–10 days) 5.69 ± 27 h while Rastan et al.  reported a longer ICU stay time of 1–46 days.
In our study mortality was 1/40 (2.5%) patients; of all the patients, one patient died during the ICU period while the mortality other studies like the study of Kim et al.  and his coauthors reported a mortality of 17.3% (18/104) and considered that an EF of less than 40% is a risk factor for mortality while Rastan et al.  demonstrated 8.6% mortality in his group of emergency CABG and he considered that a patient with cardiogenic shock or bad HD before surgery is a risk factor for death.
Generally, our results are in the same line with the results of, Järvinen et al. , which showed a significant improvement in functional capacity and New York Heart Association class during the first year after CABG.
The small sample size was one of the limitations we encountered in our study as our trial aimed to show benefit of emergency CABG in LMCAD and therefore excluded patients with cardiogenic shock and severe hemodynamic instability.
The short-term follow-up in our study was considered a limitation as longer-term studies may reveal additional parameters associated with mortality, myocardial infarction, that were not significant at 6 months.
| Conclusion|| |
Our study demonstrated that the patients undergoing emergency coronary artery bypass surgery have a significant higher preoperative risk especially with myocardial impairment. Despite the higher mortality rate, a reasonable and favorable clinical outcome can be achieved when those patients who tolerate the surgery and survive. Also, we assume that establishing hemodynamic stability in conjunction with the cardiologist prior to surgery significantly influences the surgical outcome.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]