Surgery for chronic total occlusion of the left main coronary artery

Unexpected normal left ventricular systolic function after total chronic occlusion of left main coronary artery and stenosis of right coronary artery: a case report and review of the literature

INTRODUCTION

Total occlusion of the left main coronary artery is a very rare finding in coronary angiography because of its highly lethal nature. Right coronary artery dominance and extensive collateral circulation are the principal determinant factors of survival after total occlusion of the left main coronary artery. The impact on the left ventricle is often significant with a profound alteration of its systolic function.

CASE PRESENTATION

We describe a 52-year-old North African man, a tobacco smoker, who presented symptoms of unstable angina related to a total chronic occlusion of his left main coronary artery with a right coronary artery stenosis. Unexpectedly, the impact on his left ventricle was absent with normal dimensions and systolic function. He underwent a successful on-pump coronary artery bypass grafting with uneventful postoperative course and good recovery.

CONCLUSIONS

Total occlusion of the left main coronary artery is a rare condition, the fact that the left ventricle retains a normal size and systolic function makes it exceptional, which must be kept in mind to avoid dangerous examinations and delayed treatment. Coronary artery bypass surgery should be considered the main treatment of total chronic occlusion of the left main coronary artery.

Myocardial protection and early outcome of different coronary surgical techniques for diabetic patients with triple vessels

BACKGROUND AND OBJECTIVES

For patients with diabetes and triple-vessel disease, coronary artery bypass grafting (CABG) surgery is a well-established procedure, but cardiopulmonary bypass support may also lead to severe complications to these patients. The aim of this study was to compare myocardial protection and early outcomes in patients with diabetes and triple-vessel disease following different coronary surgical techniques.

DESIGN AND SETTINGS

Prospective randomized trial of patients treated at the First Affiliated Hospital of China Medical University over a 3-year period (2011- 2013).

METHODS

In a single-center randomized trial, 668 patients with diabetes and triple-vessel disease were randomly assigned to off-pump (OPCAB) (number [n]=222), on-pump beating heart (OnP-BH) (n=223), and conventional CABG (OnP) (n=223) between January 2011 and October 2013. Myocardial injury was assessed by measuring the serial release of cardiac troponin I (cTnI) preoperatively, 1 hour, 12 hours, 24 hours, and 72 hours postoperatively. The early outcomes were compared among these 3 groups.

RESULTS

Preoperative characteristics of the patients in all 3 groups were similar. No significant difference was found regarding the number of anastomoses, the use of the internal thoracic artery, postoperative new-onset atrial fibrillation, hemodialysis, stroke, reoperation for bleeding, and infective complications in the 3 groups (P > .05). The complete revascularization, postoperative drainage loss, intra-aortic balloon pump support, blood requirements, postoperative myocardial infarction, pulmonary complications, gastrointestinal complications, inotropic requirements > 24 hours, ventilation > 24 hours, intensive care unit stay > 24 hours, and in-hospital stay > 7 days were significantly lower in the OPCAB group than in the other 2 groups (P < .05). In-hospital mortality was lower in the OPCAB group than in the other 2 groups, but no statistical difference was observed (P > .05). Preoperative cTnI in the 3 groups was similar (P > .05); however, the lowest cTnI value was noted in the OPCAB group, followed by the OnP group, and it was highest in the OnP-BH group 1 hour, 12 hours, 24 hours, and 72 hours postoperatively (P < .05).

CONCLUSION

OPCAB is superior to the OnP-BH and OnP techniques in terms of postoperative complications and myocardial protection in patients with diabetes and triple-vessel disease. Myocardial injury in the OnP-BH group was significantly higher than that in the OnP group.

On-pump with beating heart or cardioplegic arrest for emergency conversion to cardiopulmonary bypass during off-pump coronary artery bypass

BACKGROUND AND OBJECTIVES

Intraoperative conversion, especially under emergent circumstances during off-pump coronary artery bypass (OPCAB), is associated with a significantly higher rate of hospital mortality. This study compared the clinical early outcomes of patients emergently converting to cardiopulmonary bypass (CPB) with or without cardioplegic arrest and evaluated the efficacy of an on-pump beating heart technique for these critically ill patients.

DESIGN AND SETTING

A retrospective study of patients treated at The First Affiliated Hospital of China Medical University over an 8-year period (2005 to 2013).

PATIENTS AND METHODS

Between January 2005 and September 2013, 104 patients were emergently converted to CPB during OPCAB. In the first 55 patients (53%), the cardioplegic arrest was performed. In the most recent 49 patients (47%), the on-pump beating heart procedure was used without cardioplegic arrest.

RESULTS

There were no significant differences in their baseline clinical characteristics, number of anastomoses performed per patient, and reasons for conversions (P > .05). A significant reduction occurred in the observed mortality between the cardioplegic arrest group and the on-pump beating heart group (25.6% vs 6.1%, P=.008). A statistical difference was found between the cardioplegic arrest group and the on-pump beating heart group in the time of CPB, peak cardiac troponin I, duration of inotropic support, time to extubation, intensive care unit stay, postoperative hospital stay, incidence of new intra-aortic balloon pump support, and pulmonary complications (P < .05). The incidence of blood requirements, postoperative myocardial infarction, new-onset atrial fibrillation, hemodialysis, stroke, infective complications, and resurgery for bleeding were lower in on-pump beating heart group, but the difference did not reach statistical significance (P > .05).

CONCLUSION

The on-pump beating heart technique is the preferred method of emergency conversion to CPB during OPCAB. It has lower postoperative mortality and morbidity than the cardioplegic arrest.

Off-pump versus on-pump coronary artery bypass surgery in patients with triple-vessel disease and enlarged ventricles

BACKGROUND AND OBJECTIVES

Off-pump coronary artery bypass grafting (OPCAB) is a popular treatment for patients with ischemic heart disease, especially for high-risk patients. However, whether OPCAB can lead to better clinical outcomes than on-pump coronary artery bypass grafting (ONCAB) in patients with enlarged ventricles remains controversial. This prospective randomized study was designed to characterize comparison of early clinical outcome and mid-term follow-up following ONCAB versus OPCAB in patients with triple-vessel disease and enlarged ventricles.

DESIGN AND SETTINGS

Prospective randomized trial of patients treated at The First Affiliated Hospital, China Medical University, over a 3-year period (2007-2010).

METHODS

A total of 102 patients with triple-vessel disease and enlarged ventricles (end-diastolic dimension >=6.0 cm) were randomized to OPCAB or ONCAB between July 2007 and December 2010. The in-hospital out.comes were analyzed. The study included a mid-term follow-up, with a mean follow-up time of 49.40 (12.88 months).

RESULTS

No significant differences were recorded in the baseline clinical characteristics of ONCAB and OPCAB groups. A statistical difference was found between the two groups at the time of extubation, intensive care unit stay, hospital stay, blood requirements, incidence of intra-aortic balloon pump support, pulmonary complications, stroke, reoperation for bleeding, and inotropic requirements > 24 hours (P < .05). The number of anastomoses performed per patient, the incidence of postoperative ventricular arrhythmia, myocardial infarction, new-onset atrial fibrillation, hemodialysis, infective complications, recurrent angina, and percutaneous reintervention were similar between the 2 groups (P > .05). The left ventricular end-diastolic dimension was significantly smaller at 6 months' follow-up in the 2 groups than it was before operation ( < .05). No differences in hospital mortality and mid-term mortality between OPCAB and ONCAB groups were found. During the follow-up, no patient in either group had undergone repeat coronary artery bypass grafting.

CONCLUSION

No differences in early and mid-term mortality were found between OPCAB and ONCAB in patients with triple-vessel disease and enlarged ventricles. However, OPCAB seems to have a beneficial effect on postoperative complications.

Meta-analysis of the effect of percutaneous coronary intervention on chronic total coronary occlusions

Background and purpose

Coronary chronic total occlusion (CTO) is the last stage of coronary artery atherosclerosis. Percutaneous coronary intervention (PCI) is a therapeutic procedure used to recanalize vessels with total occlusion. However, successful recanalization of CTO is still not optimal, and the key influence factors are still uncertainty. Therefore, a scientific evaluation on the effective of PCI for CTO treatment is necessary.

Methods

Relevant studies of PCI treatment for CTO were examined. Data were extracted and assessed by two independent clinical experts. Embase, PubMed and Medline et al. were used as database. The main research key words include “CTO”, “PCI”, “Stent”, “Reopen”, “long-term”, “follow-up” and “outcome”. Quality assessment was carried out according to the Cochrane Handbook. The selected data were pooled and analyzed using fixed-effect model and random-effect model. Heterogeneity was assessed using the I² test, Q test, L’abbe and Galbraith. Comprehensive Meta -Analysis 2.0 and Metanalysis 1.0 were used for statistics analysis in this research.

Results

A total of 16 articles involving 6695 cases in successful CTO recanalization (CTO success group) and 2370 cases in failed CTO recanalization(CTO failure group) were included in this research. Low CTO success was associated with elder age, previous coronary artery bypass graft surgery (CABG) history, multi-vessel diseases and right coronary artery disease lesion. Six follow-up variables including major adverse cardiac events (MACE), recurrent myocardial infarction (MI), all-cause death, incidence of angina, subsequent CABG and cumulative survival rate were found significantly reduced associated with CTO success.

Conclusions

Clinical baseline characteristics such as age, previous CABG history and lesion baseline characteristics such as lesion length, multi-vessel diseases might be important factors influencing the successful rate of CTO recanalization. Compared to CTO failure patients, all six follow-up variables showed advantage for CTO success patients.