Right ventricular infarction complicating coronary artery bypass grafting

Intraoperative right ventricular infarction immediately after coronary artery bypass grafting is a rare and potentially serious complication. We report a case in which an additional coronary artery bypass graft to a right ventricular branch with 99% stenosis brought about recovery from profound acute right ventricular failure. This case shows that complete revascularization to all graftable vessels, including even the right ventricular branch, is mandatory for successful coronary artery bypass grafting.     

Early coronary artery bypass grafting for complicated acute myocardial infarction

The occurrence of unstable angina or cardiogenic shock after an acute myocardial infarction characterizes a subgroup of patients with increased morbidity and mortality. To assess the efficacy of surgical revascularization in this cohort, 96 patients who underwent coronary artery bypass grafting within 6 weeks of an acute myocardial infarction were compared to 485 patients who underwent myocardial revascularization without recent infarction. Fourteen (15%) of the patients with acute infarction were in cardiogenic shock and 82 (85%) patients had unstable angina at the time of surgery. Preoperatively, the patients with acute infarction compared to the patients without acute infarction were older (+3.5 years), had an increased incidence of congestive heart failure (21% vs 13%), and had a lower mean ejection fraction (4% vs 65%). Preoperative intraaortic balloon support was used in 9 patients (65%) with cardiogenic shock, and in 16 patients (19%) with unstable angina. Mean interval to surgery from time of infarction was 14.9 days. Overall operative mortality was 7.3% (7 patients) for the acute infarction group 28% for patients with cardiogenic shock and 3.7% for patients with unstable angina compared to 3.7% for the group of patients without recent infarction. Earlier surgical intervention did not result in a significant increase in operative mortality. Discriminant analysis of the recent infarction cohort demonstrated that preoperative ejection fraction less than 45% and age greater than 70 were the most significant predictors of early mortality. Of the 89 patients surviving surgery, actuarial survival was 97% at 3 years with no late infarctions. At follow-up 95% of survivors were NYHA Class I or II.(ABSTRACT TRUNCATED AT 250 WORDS)     

Beating heart coronary artery bypass grafting for acute myocardial infarction

We consider that off-pump coronary artery bypass grafting (CABG) [OPCAB], which results in local myocardial ischemia, is more effective for patients with acute myocardial infarction (AMI) than conventional CABG under cardiac arrest with global myocardial ischemia. Twenty-one patients (15 males, 6 females) received OPCAB for AMI, among whom surgery was performed following percutaneous coronary intervention (PCI) failure in 4 and PCI was performed prior to OPCAB in 2, while PCI was not performed in the remaining 15. Preoperatively, 16 patients had intraaortic balloon pumping (IABP), and 4 had IABP and percutaneous cardiopulmonary support (PCPS). The mean interval from onset to surgery was 11.7 (range 3 to 40) hours. In 20 cases, a complete revascularization was performed. The mean number of bypasses was 2.3 and OPCAB was carried out in 14 patients. In 2 cases, OPCAB was converted to on-pump beating CABG for complete revascularization. Fourteen patients (67%), each maintained with preoperative left ventricular ejection fraction (EF), were discharged with an elective bypass. Four patients died after on-pump beating CABG, in whom EF was lower than 10%. In addition, 3 died of low cardiac output syndrome (LOS) under PCPS and 1 of ventricular fibrillation. Based on our results, we considered that complete revascularization using OPCAB was effective for cases of AMI with PCI difficulty. However, in shock cases requiring PCPS, cardiac function was not improved even after revascularization. Therefore, it is necessary to study new procedures for shock cases during the period from onset to surgery.     

Troponin levels in patients with myocardial infarction after coronary artery bypass grafting

BACKGROUND: The objective of this study was to evaluate serum cardiac troponin T and I levels in patients in whom electrocardiogram, myocardial scan, and serum CK-MB levels of the MB isoenzyme of creatine kinase indicated perioperative myocardial infarction (MI) after coronary artery bypass grafting (CABG). METHODS: We studied 590 patients who underwent CABG at the Montreal Heart Institute between 1992 and 1996. Postoperative cardiac troponin T levels (493 patients), troponin I levels (97 patients), and activity of the MB isoenzyme of creatine kinase, electrocardiograms, clinical data, and clinical events were recorded prospectively. The diagnosis of perioperative PMI was defined by a new Q wave on the electrocardiogram, by serum levels of the MB isoenzyme of creatine kinase higher than 100 IU/L within 48 hours after operation, or both. RESULTS: After CABG, 22 patients in whom troponin T levels (22/493, 4.5%) and 6 patients in whom troponin I levels (6/97, 6.2%) were measured had sustained a perioperative MI according to current diagnostic criteria. In these patients, troponin T levels higher than 3.4 microg/L 48 hours after CABG best detected the presence of perioperative MI, with an area under the receiver operating characteristic curve of 0.95, a sensitivity of 90%, a specificity of 94%, a positive predictive value of 41%, a negative predictive value of 99%, and a likelihood ratio of 15. Serum troponin I levels higher than 3.9 microg/L 24 hours after CABG confirmed the perioperative MI with an area under the receiver operating curve of 0.86, a sensitivity of 80%, a specificity of 85%, a positive predictive value of 24%, a negative predictive value of 99%, and a likelihood ratio of 5. CONCLUSIONS: Serum troponin T levels higher than 3.4 microg/L 48 hours after CABG correlated best with the diagnosis of perioperative MI. Serum troponin T levels greater than 3.9 microg/L 24 hours after CABG also correlated with the diagnosis of perioperative MI, although a larger experience is needed to confirm the validity of the chosen cutoff value.     

Off-pump coronary artery bypass grafting for patients with cardiogenic shock due to acute myocardial infarction

Off-pump coronary artery bypass (OPCAB) is less invasive, so we have recently been expanding the indication. We performed OPCAB for 3 patients with cardiogenic shock due to acute myocardial infarction (AMI). PATIENTS: All patients were supported hemodynamically by intra-aortic balloon pumping (IABP) prior to surgery. RESULTS: We performed the revascularization of territories for the left anterior descending artery (LAD) and right coronary artery (RCA) in these high risk patients using OPCAB technique to improve the hemodynamic state. In all patients, IABP was removed within 48 hours after surgery and the postoperative course was uneventful. CONCLUSIONS: It seems that OPCAB is a useful and effective procedure for a selected patient even with cardiogenic shock due to AMI.     

Perioperative myocardial infarction in patients undergoing off-pump coronary artery bypass grafting

Two patients in whom myocardial infarction in the inferior wall occurred after off-pump coronary artery bypass grafing (OPCAB) are described. In both patients, the right coronary artery had no critical lesion and was not grafted. There was no ischemic episode during operation. Coronary artery spasms and/or intracoronary thrombus formation may have been causes of these events. To our knowledge, this is the first report on perioperative myocardial infarction in OPCAB.     

Off-pump coronary artery bypass grafting in a patient with AIDS,acute myocardial infarction,and severe left main coronary artery disease

A 48-year-old male patient with AIDS presented with postinfarct unstable angina, decreased left ventricular function (EF 35%), significant left main coronary artery disease, and total occlusion of the proximal left anterior descending and right coronary arteries. In order to avoid the potential immunosuppressive effect of cardiopulmonary bypass (CPB) in an already compromised host with an already low CD4+ helper/inducer T cell count (180/microL) and high retroviral load (165,000 copies/mL), the application of beating-heart technology and off-pump coronary bypass grafting was an ideal indication. The patient underwent successfully off-pump/CPB coronary revascularization. The triple drug combination of highly active antiretroviral therapy (HAART) was resumed postoperatively. The patient was discharged from the hospital on the 7(th) postoperative day. The CD4+ count was 142/microL and the viral load decreased to 450 copies/mL. Seven months post-operatively the patient was free of angina and without shortness of breath. The CD4+ count was 160/(m)L and the viral load undetectable. Improved survival of HIV positive patients has resulted in a shift from caring for terminally ill patients to caring for patients with chronic illness. While protease inhibitors have positively affected survival, they may also cause plasma lipid abnormalities, which can lead to severe premature coronary artery disease. Therefore, an increasing population of AIDS and HIV positive patients with coronary artery disease may require cardiac interventions in the near future. Coronary revascularization without CPB and its potential immunocompromising effect may play an important role in patients with severe coronary artery disease and AIDS.     

急性心肌梗死后冠状动脉旁路移植术时机选择

目的确定急性心肌梗死（AMI）后行冠状动脉旁路移植术（CABG）时机对术后30d死亡率的影响。方法233病例分为心肌梗死和心绞痛两组，对多个风险因素通过单因素、多因素分析，以确定AMI后不同时段手术是否为死亡的独立风险因素。结果233例中男176例（75．4％），女57例（24．5％）。年龄34～86岁，平均（65．6±9．2）岁。平均移植血管（3．46±0．89）支，137例（58．8％）应用乳内动脉137根。总死亡率4．3％（10／233例）。AMI距手术时间≤3d者，手术死亡6例（14．6％，6／41例），较心绞痛组3例（2．3％，3／130例）显著增高（P=0．033）；4～10d者1例（2．7％，1／37例）与心绞痛组相比差异无统计学意义（P=0．67），11～30d者无手术死亡。结论急性心肌梗死3d后行冠脉旁路移植术较为安全。     

Coronary artery bypass grafting after acute ST-elevation myocardial infarction

ObjectivesThe study objectives were to describe the trends and outcomes of isolated coronary artery bypass grafting after ST-elevation myocardial infarction using a nationwide database.MethodsWe queried the 2002-2016 National Inpatient Sample database for hospitalized patients with ST-elevation myocardial infarction who underwent isolated coronary artery bypass grafting. We report temporal trends, predictors, and outcomes of coronary artery bypass grafting in the early (2002-2010) and recent (2011-2016) cohorts.ResultsOf 3,347,470 patients hospitalized for ST-elevation myocardial infarction, 7.7% underwent isolated coronary artery bypass grafting. The incidence of isolated coronary artery bypass grafting after ST-elevation myocardial infarction decreased over time (9.2% in 2002 vs 5.5% in 2016, P_trend < .001), whereas perioperative crude in-hospital mortality did not change (5.1% in 2002 vs 4.2% in 2016, P_trend = .66), coinciding with an increase in the burden of comorbidities. There was an increase in performing isolated coronary artery bypass grafting on hospitalization day 3 or more, as well as an increase in the use of mechanical support devices and precoronary artery bypass grafting percutaneous coronary intervention. In the early cohort, isolated coronary artery bypass grafting on days 1 and 2 was associated with higher in-hospital mortality. In the recent cohort, coronary artery bypass grafting on day 2 had similar in-hospital mortality compared with day 3 or more and lower rates of acute kidney injury, ischemic stroke, ventricular arrhythmia, and length of hospital stay.ConclusionsIn this nationwide analysis, there has been a decline in the use of isolated coronary artery bypass grafting after ST-elevation myocardial infarction. Isolated coronary artery bypass grafting on day 1 was performed in sicker patients and was associated with higher in-hospital mortality than coronary artery bypass grafting performed on day 3 or more. In the recent cohort, isolated coronary artery bypass grafting on day 2 had similar in-hospital mortality compared with day 3 or more.     

Emergency coronary artery bypass graft surgery for threatened acute myocardial infarction related to coronary artery catheterization

In 20 patients undergoing cardiac catheterization, usually involving balloon-catheter dilation or streptokinase infusion, catheter-induced coronary artery intimal damage resulted in severe chest pain, electrocardiographic evidence of obstruction or dissection of a major coronary artery. These patients were surgically revascularized within 8 hours after the onset of the acute chest pain syndrome. Our experience with pharmacological and catheter-related manipulations to improve coronary blood flow after the ischemic episode but before operation suggested that the additional time spent in the catheterization laboratory was worthwhile. The injured coronary artery was the left anterior descending in 10 patients, the right in 8, the left main in 1 patient, and an obtuse marginal branch of the circumflex in 1. The average number of grafts per patient was 2.5; only 6 patients had single bypass grafts. In 5 patients, intraaortic balloon pumping was used either preoperatively or postoperatively. Inotropic support was used postoperatively in 5 patients, and 7 patients received lidocaine for ventricular irritability. Abnormal elevation of the serum isoenzyme of creatine kinase (CK-MB) was seen in 8 patients, and new Q waves were noted in 4 patients; 3 of these 4 patients with new Q waves also had abnormal serum CK-MB levels. Global ejection fraction obtained by the equilibrium-gated blood pool scan postoperatively was 60 +/- 3%, which was similar to the 62 +/- 3% obtained from the contrast-determined ventriculogram done preoperatively prior to the catheter-related injury. There were no early or late deaths, but morbidity was much higher in the group who had emergency coronary artery bypass grafting (CABG) compared with those who had elective CABG.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of Coronary artery bypass grafting in acute myocardial infarction

OBJECTIVES: We evaluated coronary artery bypass grafting (CABG) in acute myocardial infarction (AMI) within 14 days of onset. METHODS: Of 1,450 patients undergoing isolated CABG in the last 12 years we retrospectively analyzed operative risk factors and studied the use of CABG in treating AMI in 66 undergoing surgery during the AMI phase. We divided them into 2 groups: Group D (deceased: n = 8) and Group S (survivors: n = 58). RESULTS: Total operative mortality was 12.1% (8/66). Univariate analysis showed the following preoperative parameters to be significant in Group D: diabetes mellitus, cardiogenic shock, shortness of the interval between AMI onset and surgery, mean peak creatine phosphokinase-MB, AMI of the left main trunk, and failed recanalization of the infarcted artery. Multivariate analysis showed diabetes mellitus, cardiogenic shock, and AMI of the left main trunk as independent risk factors for hospital mortality. Intra-operative parameters between groups showed no statistical difference. Mortality in patients who did not suffer cardiogenic shock was zero. CONCLUSION: Maintenance of hemodynamics in the early phase is vital in treating AMI. The most important element in surgical intervention is revascularization of main branches. We concluded that CABG in AMI involves relatively low risk.     

Emergency coronary artery bypass grafting for failed percutaneous transluminal coronary angioplasty]

There were 1151 patients who underwent PTCA at our facilities from August 1984 to December 1990. The records of 298 patients were reviewed from August 1984 to June 1988 (former period), and were compared with records of 853 patients undergoing treatment after June 1988 (latter period). Of 852 elective PTCA procedures, complete occlusion of the lesion increased from 2.3% in the former period to 17.5% in the latter period, while for partial occlusion there were 60.4% in the former and 60.5% in the latter. Emergency PTCA for acute myocardial infarction decreased from 37.2% in the former to 22% in the latter. The number of patients with multivessel disease increased slightly from 43.6% in the former to 46.8% in the latter. The success rate for patients who underwent elective PTCA for complete occlusion was 42.8% in the former and 49.6% in the latter, while for partial occlusion it was 87.2% in the former and 91.8% in the latter. The success rate for patients requiring emergency PTCA was 73.8% in the former and 90.4% in the latter. Of the patients undergoing elective PTCA, acute coronary closure occurred in 3% of the former and in 1% of the latter, while for patients requiring emergency PTCA, there were 4.4% in the former and 2.7% in the latter. Of the 8 patients who required emergency CABG, elective PTCA was unsuccessful in 4 cases and emergency PTCA was also unsuccessful in the other 4; in other words, 4 of a total 852 elective PTCAs (0.47%) and 4 of 299 emergency PTCAs (1.3%) for an overall figure of 8/1151 (0.7%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Emergency conversion in off-pump coronary artery bypass grafting

Emergency conversion to cardiopulmonary bypass in off-pump coronary artery bypass grafting is recognized to increase operative mortality and morbidity. We conducted a retrospective review of 616 consecutive patients who were planned for off-pump coronary artery bypass grafting from April 2001 to July 2004. Fourteen patients (2.3%) required emergency conversion to cardiopulmonary bypass. Operative mortality was 13.3% in the conversion group and 1.2% in the non-conversion group (P<0.001). The incidence of reoperation for bleeding was 7.1% and 1.0%, respectively (P=0.032) and that of respiratory failure was 35.7% and 3.3%, respectively (P<0.001). Multivariable analysis showed that mitral regurgitation and chronic obstructive pulmonary disease were predictors of emergency conversion with all causes except for bleeding, and that mitral regurgitation and no use of a heart positioning device were predictors of emergency conversion due to hemodynamic compromise during distal anastomosis of the circumflex artery territory. In conclusion, emergency conversion in off-pump coronary artery bypass grafting increases operative mortality and morbidity. Mitral regurgitation and chronic obstructive pulmonary disease are risk factors for emergency conversion. Use of a heart positioning device decreases hemodynamic compromise during anastomosis of the circumflex artery territory.     

Off-pump coronary artery bypass grafting surgery in early stage myocardial infarction treatment

We evaluated the surgical results of off-pump coronary artery bypass grafting (OPCAB) performed within the first 12 h of infarction in patients with acute myocardial infarction. From January 2005 to January 2007, emergency coronary artery bypass grafting without cardiopulmonary bypass was performed in 56 patients with acute coronary syndromes. The mean age was 62.9 (range, 51-86) years. All patients underwent OPCAB via sternotomy. An average of 2.5 +/- 1.1 grafts per patient were performed. The mortality rate was 7.1% (4 of 56 patients). One patient suffered from postoperative stroke (1.7%), and 3 (5.3%) needed hemofiltration for acute renal failure. Postsurgery elective coronary angiography (n = 21) showed no significant stenosis. These results indicate that emergency OPCAB can be applied to patients with acute myocardial infarction with low morbidity and mortality and excellent early results.     

Percutaneous transluminal coronary angioplasty in patients with previous coronary artery bypass grafting]

Percutaneous transluminal coronary angioplasty (PTCA) has been used to treat patients with previous coronary artery bypass grafting (CABG). Seven patients with previous CABG underwent coronary artery or vein graft angioplasty following a recurrence of symptoms. Fifteen lesions were attempted in 7 patients. The primary angiographic success rate was 100%. The primary angiographic success rate was defined as reduction of a stenosis by at least 20% of the vessel diameter, leaving a stenosis of less than 60%. There were no complications following PTCA such as death or myocardial infarction. No patients were referred for urgent surgery. Three patients have undergone another PTCA after 3 months and remain well. All patients at follow-up continue to have improved symptoms. Our experience suggests that the patients with recurrence of coronary artery or bypass stenosis following CABG may be suitable for PTCA.