Mortality in patients undergoing coronary artery bypass surgery after myocardial infarction

Data on 1,700 patients who underwent coronary artery bypass surgery without additional cardiovascular procedures at the Texas Heart Institute were analyzed, relating the interval between myocardial infarction and operation to early mortality (within 30 days after operation). Patients who underwent coronary artery bypass surgery after a recent infarction (within 2 months before operation) had a higher rate of early mortality (14.5 percent) than patients who had an old infarction (6.9 percent) or no previous infarction (4.1 percent). The interval between recent infarction and operation was most significant. Mortality in patients who underwent operation within the first 7 days after acute infarction (38.1 percent) was more than six times greater than in patients who were operated on 31 to 60 days after infarction (5.8 percent). Mortality of those operated on 8 to 30 days after infarction was 16.4 percent. Elective coronary artery bypass surgery after recent infarction is best accomplished after the first 30 days, when there is no increased risk to the patient. Emergency coronary artery bypass after complicated acute myocardial infarction may be a lifesaving procedure, but it is associated with increased early mortality and should be reserved for those whose condition has not responded to aggressive medical therapy.     

Quantification of peri-operative myocardial infarction after coronary artery bypass surgery.

Dear Editor, In a recent study in the Journal, Steuer and colleagues¹ reportthat elevated biochemical markers after on-pump CABG correspondto the amount of peri-operatively infarcted myocardium as measuredby delayed-enhancement cardiac MRI (DE-MRI). They found that18 out of 23 (78%)     

Long-term prognosis after myocardial infarction in patients with previous coronary artery bypass surgery

A group of 205 patients hospitalized with myocardial infarction 2 to 162 months (mean 66) after bypass surgery and 205 control patients with myocardial infarction were compared and followed up for 34 +/- 25 months after hospital discharge. At baseline the postbypass group contained more men (p less than 0.03) and more patients with previous myocardial infarction (p less than 0.06), but the groups were otherwise comparable. Indexes of infarct size were lower in postbypass patients: sum of ST elevation, QRS score, peak serum creatine kinase (CK) (1,115 +/- 994 versus 1,780 +/- 1,647 IU/liter) and peak MB CK (all p less than or equal to 0.001). Postmyocardial infarction ejection fraction was 45 +/- 15% in the postbypass group and 43 +/- 15% in the control group (p = NS); in-hospital mortality rate was 4 and 5%, respectively (p = NS). When patent grafts were taken into account, the two groups were comparable in extent of coronary artery disease. At 5 years after discharge, cumulative mortality was similar in the postbypass and control groups (30 versus 25%, respectively, p = NS). However, postbypass patients had more reinfarctions (40 versus 23%, p = 0.007), more admissions for unstable angina (23 versus 18%, p = 0.04) and more revascularization procedures (34 versus 20%, p = 0.04) than did control patients. The total for these events at 5 years was 70% in the postbypass group and 49% in the control group (p = 0.001). Thus, although patients with previous bypass surgery who develop acute myocardial infarction have a smaller infarct, their subsequent survival is no better than that of other patients with acute myocardial infarction. They experience more reinfarctions and unstable angina. Previous bypass surgery is an important clinical marker for recurrent cardiac events after myocardial infarction.     

Use of coronary angioplasty, bypass surgery, and conservative therapy for treatment of coronary artery disease over the past decade

Aims There is a continuous increase in the number of percutaneoustransluminal coronary angioplasty pro-cedures performed peryear per population in most industrialised countries. This analysissearches for trends in treatment decisions after diagnosticcoronary angiography. Methods and Result The degree of coronary artery disease and the therapeutic strategywere determined retro-spectively in consecutive patients undergoingcoronary angiography at a Swiss university hospital during threedifferent time periods in the past 11 years (n=750 in 1994,n=500 in 1990, and n=545 in 1983). The indication for coronaryangioplasty rose from 45% in 1983 to 78% in 1990 and 87% in1994 in patients with one-vessel disease, from 25% to 38% and71% in patients with two-vessel disease, and from 10% to 24%and 29% in patients with three-vessel disease. In contrast,the use of conservative therapy declined with time, independentof the severity of coronary artery disease. Indications forcoronary artery bypass grafting decreased in patients with two-vesseldisease, but did not change in patients with three-vessel diseaseover the 11-year period. Conclusions The use of coronary angioplasty, bypass surgery, and conservativetherapy changed drastically over the past decade, with an increasinguse of angioplasty and a decreasing use of conservative therapyin one-vessel and multivessel disease, and of bypass surgeryin two-vessel disease. The expansion of coronary angioplastyis mainly related to increased use in patients previously treatedconservatively.     

Follow-up catheterization of patients with myocardial infarction during coronary artery bypass surgery.

Of 197 consecutive patients having aortocoronary bypass grafts over a 30 month period, 38 (19 per cent) had ECG evidence of myocardial infarction. The infarctions occurred more commonly in patients receiving multiple grafts. The infarctions were usually in areas supplied by grafted vessels. The infarctions occurred most often in the inferior wall, even when multiple vessels were grafted. Eleven patients with intraoperative infarction have had repeat postoperative coronary arteriograms. Seven had all grafts patent; three of these patients had hypokinesis of the infarcted wall. Four of the 11 patients had one or more occluded grafts; three of these patients had an area of hypokinesis. We conclude that intraoperative myocardial infarction is a common problem in aortocoronary bypass surgery and is not necessarily caused by graft occlusion.     

冠状动脉搭桥围术期急性心肌梗死紧急再搭桥

目的：回顾性分析冠状动脉搭桥围术期急性心肌梗死急诊再搭桥的临床经验。方法：在510例冠状动脉搭桥患中，5例患在术后4h内因急性心肌梗死需急诊再搭桥，发生率0．98％。5例患中，男女比例为4：1，年龄56－77岁（平均63．6岁），均为冠状动脉三支血管病变（3例伴左主干病变），手术中搭桥3－5支（人均搭桥3．6支），左乳内动脉桥5根，其余为大隐静脉桥。2例在关胸后20min，3例在回重症监护病房后2－4h出现急性心肌缺血表现（明显心电图ST－T变化），伴室颤2例，5例血液动力学均不稳定，药物处理难以稳定血液动力学。全部患均立即送手术室（2例仍在手术室），急诊再次开胸。探查发现，2例患静脉桥（分别搭桥到回旋支第二钝缘支和右冠状动脉后降支）内急性血栓形成；另3例所有静脉桥良好，但左室前壁收缩运动明显减弱，结合心电图变化，诊断为左乳内动脉灌注不良。重新建立体外循环，清除桥内血栓重新搭桥2例（1例在非体外循环心脏跳动下进行）；另取一段静脉搭桥到左乳内动脉－左前降支吻合口远端的左前降支3例。结果：5例患顺利度过手术，均置入主动脉内球囊反搏，支持22－25h（平均42h）。手术后呼吸机支持4h－18d（平均7．3d）合并消化道出血4例，肾功能不全2例，肺部感染2例，切口感染1例。手术后住院时间12－35d，平均21d。全组均痊愈出院。结论：冠状动脉搭桥围术期急性心肌梗死应重在预防。如怀疑桥有问题，急诊再搭桥是良好选择，但手术后并发症发生率明显增加。     

Coronary angioplasty in patients with prior coronary artery bypass surgery: all prior coronary artery bypass surgery patients and patients more than 5 years after coronary bypass surgery

Percutaneous transluminal coronary angioplasty (PTCA) has been used successfully in patients who have had prior bypass surgery (CABG) as a means of revascularizing the myocardium and avoiding repeat myocardial revascularization. However, angioplasty has been considered inappropriate as a means of dilating old saphenous vein grafts. The first section of this article details the authors' experience with PTCA of prior CABG patients, and the second section discusses the results of PTCA in the subset of patients 5 or more years after their last coronary bypass surgery. These data may make individuals rethink the appropriateness of PTCA in old saphenous vein grafts.     

Effects of intraaortic balloon pumping on coronary hemodynamics after coronary angioplasty in patients with acute myocardial infarction.

It has been reported that intraaortic balloon pumping can prevent reocclusion after coronary angioplasty for acute myocardial infarction. The speculated mechanism has been the production of markedly enhanced diastolic coronary perfusion pressure; however, most studies have reported that intraaortic balloon pumping has little effect on coronary blood flow. To assess the effectiveness of this procedure, we studied 12 patients with acute anterior myocardial infarction who were undergoing coronary angioplasty and intraaortic balloon pumping. After successful angioplasty, coronary blood flow velocity was measured with a coronary Doppler catheter before and during intraaortic balloon pumping. Although mean coronary blood flow velocity was unchanged, intraaortic balloon pumping increased peak coronary blood flow velocity from 34.6 +/- 5.0 cm/sec (mean +/- SEM) to 46.7 +/- 5.8 cm/sec (p < 0.005). Such an increase in peak coronary blood flow velocity seemed to be a mechanism by which intraaortic balloon pumping could prevent reocclusion after coronary angioplasty for acute myocardial infarction.     

Emergency coronary artery bypass surgery after intracoronary thrombolysis for evolving myocardial infarction.

Sixteen patients underwent emergency coronary artery bypass surgery immediately after intracoronary streptokinase infusion for acute evolving myocardial infarction. Of these, 11 patients had 70% residual stenosis in the recanalised vessel, and in five thrombolysis was unsuccessful. There were no hospital deaths. All the patients sustained myocardial necrosis, the peak activity of creatine phosphokinase correlating with the time to reperfusion. Chest tube drainage (mean 960 ml) was significantly higher than for control patients but did not correlate with the total dosage of streptokinase. No patients had further myocardial infarction or developed recurrent angina. Selected patients may benefit from coronary bypass surgery after intracoronary streptokinase infusion. If necessary this may be performed immediately with low mortality and morbidity.     

Usefulness of angioplasty during acute myocardial infarction in patients with prior coronary artery bypass grafting

The efficacy and risk of reperfusion strategies for myocardial infarction in patients with prior coronary artery bypass surgery are uncertain. In this study 72 patients with prior bypass grafting underwent direct percutaneous transluminal coronary angioplasty without antecedent thrombolytic therapy. There were 26 anterior and 46 inferior infarctions, including 11 patients (15%) in cardiogenic shock. The baseline ejection fraction was less than 40% in 47 (65%) patients. Angioplasty was successful in 41 of 48 (85%) vein grafts and 24 of 24 (100%) arteries (difference not significant) at 5.1 +/- 4.0 hours from the onset of symptoms (79% treated less than 6 hours). There were no urgent bypass operations, strokes or transfusions. In-hospital survival was 90% (nonshock 95% vs shock 64%, p less than 0.01). Symptomatic acute reclosure occurred in 1 patient. Predischarge coronary arteriography in 34 patients demonstrated continued vessel patency in 32 infarct vessels (94%), although 5 of these vessels were redilated for restenoses. Predischarge paired ventriculography in 26 patients showed an increase in ejection fraction from 44 +/- 16% to 51 +/- 18% (p less than 0.01). One- and 3-year actuarial survival was 89 and 87%. Thus, prior coronary surgery should not preclude reperfusion therapy by direct angioplasty, which can be accomplished with low procedural risk, improvements in ventricular function and excellent in-hospital and late survival.     

Late outcome of multivessel coronary artery disease after angioplasty or bypass surgery

Background. Results from randomized trials to determine optimal treatment for patients with multivessel coronary disease are not yet available. Thus, the early and late outcomes of 191 PTCA and 221 CABG patients done in 1985-86 were evaluated. Methods and Results. CABG patients selected had more coronary risk factors and more severe coronary artery disease compared to PTCA patients. Comparison of the initial outcome showed that clinical success without major cardiovascular events was similar (93.7% for PTCA vs. 90.0% for CABG; p=n.s.). Five year followup was obtained in 99.0% of PTCA patients and 94.4% of CABG patients. In the PTCA group, 89.8% were alive, 4.8% had sustained an MI, and repeat revascularization was required in 46.8%. In the CABG group, 87.1% were alive, 3.2% had had a MI, and 3.5% required repeat revascularization. Statistical comparison demonstrated no difference between the groups in survival or late cardiac events, but rate of repeat revascularization was significantly higher for PTCA patients (p less than 0.0001). Incompleteness of revascularization (p<0.01) was independently associated with an increased need for repeat revascularization in the PTCA group. In the CABG group, depressed left ventricular function (p less than 0.001) and female sex (p<0.01) were associated with lower survival rates. An analysis of cost per patient showed that the strategies were comparable. Conclusions. PTCA and CABG in multivessel disease patients have similar early results and comparable rates of survival and late cardiac events. Significantly more repeat revascularization is required in PTCA patients to maintain these results.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiac troponin I in perioperative myocardial infarction after coronary artery bypass surgery

BACKGROUND AND AIMS: Myocardial infarction after coronary artery bypass grafting is a serious complication and one of the most common causes of perioperative morbidity and mortality. The present study was designed to determine the relevance of serum cardiac troponin I as a specific diagnostic marker for perioperative myocardial infarction. METHODS: A cohort of 64 patients undergoing coronary artery bypass grafting was enrolled for prospective study. Postoperative blood samples were extracted and analyzed for total creatine kinase (CK), CKMB and cardiac troponin I activity. Perioperative infarction was defined as the development of new Q waves in the postoperative electrocardiogram together with congruent regional wall motion abnormalities in the echocardiogram and CK values greater than 400 IU/l with MB fraction greater than 40 IU/l. RESULTS: Perioperative infarction occurred in 12 patients. Higher cardiac troponin I values were observed in patients experiencing perioperative myocardial infarction than in those without infarction (p < 0.001). Cardiac troponin I values higher than 12 ng/ml 10 h after release of the aortic clamp best detected the presence of perioperative myocardial infarction, with an area under the characteristic receiver operating curve of 0.91 (95% CI, 0.82-0.97), a sensitivity of 90.9%, and a specificity of 88.5%.The mean stay in the intensive care unit was significantly longer for patients who suffered perioperative myocardial infarction (6.5 8.6 days) than for patients without perioperative infarction (4.7 7.5 days) (p < 0.005). CONCLUSIONS: Cardiac troponin I elevation appears to be an early, specific marker for the diagnosis of perioperative myocardial infarction after coronary artery bypass grafting.     

Emergency coronary artery bypass surgery after intracoronary thrombolysis for evolving myocardial infarction

Sixteen patients underwent emergency coronary artery bypass surgery immediately after intracoronary streptokinase infusion for acute evolving myocardial infarction. Of these, 11 patients had 70% residual stenosis in the recanalised vessel, and in five thrombolysis was unsuccessful. There were no hospital deaths. All the patients sustained myocardial necrosis, the peak activity of creatine phosphokinase correlating with the time to reperfusion. Chest tube drainage (mean 960 ml) was significantly higher than for control patients but did not correlate with the total dosage of streptokinase. No patients had further myocardial infarction or developed recurrent angina. Selected patients may benefit from coronary bypass surgery after intracoronary streptokinase infusion. If necessary this may be performed immediately with low mortality and morbidity.     

Clinical efficacy of intra-aortic balloon pumping in treating patients with acute myocardial infarction with left main coronary artery disease

<正>Objective To evaluate the efficacy and safety of intra-aortic balloon pump(IABP) counter pulsation in the treatment of ST-segment elevation myocardial infarction(STEMI) with concurrent left main coronary artery(LM-CA) disease. Methods A retrospective analysis was performed     

Inhospital outcome of acute myocardial infarction in patients with prior coronary artery bypass surgery

Objectives Our goals were to compare the characteristics of patients with and without prior coronary artery bypass graft (CABG) presenting with acute myocardial infarction (MI) with or without ST elevation/left bundle branch block (LBBB), and to evaluate the effect of ST shift on inhospital mortality. Methods and Results Using the National Registry of Myocardial Infarction-3 Registry, we identified 112,697 patients with acute MI without exclusion criteria. Of these, 15,936 (14.1%) had prior CABG. Patients with prior CABG had more adverse characteristics and were less likely to have ST elevation/LBBB than patients without prior CABG. The unadjusted mortality for ST elevation/LBBB patients was higher in patients with prior CABG versus without (16.2% vs 14.1%, P = .0001), whereas in patients without ST elevation/LBBB, prior CABG conferred a lower unadjusted mortality versus without (10.1% vs 12.4%, P = .0001). Adjusting for baseline differences, prior CABG was weakly associated with inhospital mortality in ST elevation/LBBB patients (odds ratio [OR], 1.11, 95% CI 1.00-1.23), but not in patients without ST elevation/LBBB (OR 0.99, 95% CI 0.92-1.07). Conclusion Acute MI patients with prior CABG are more likely to present without ST elevation/LBBB than patients without prior CABG. Prior CABG was weakly associated with inhospital mortality in patients with ST elevation/LBBB, but not in patients without these electrocardiographic findings. This suggests the differences in absolute mortality rates between patients presenting with MI with and without a history of prior CABG are largely caused by differences in baseline characteristics and presentation. (Am Heart J 2002;144:463-9.)     

Role of angioplasty in patients with previous coronary artery bypass surgery

Fifty-nine patients with previous coronary artery bypass surgery (CABG) underwent coronary artery or vein graft angioplasty following a recurrence of symptoms, 141 lesions were attempted in 70 procedures. The overall angiographic success rate was 77%. Some angiographic success was achieved in 83% of patients. Complications included myocardial infarction in three (4.3%), death in one (1.4%), and iliac artery thrombosis in one (1.4%). No patients were referred for urgent surgery. Twenty-eight patients have undergone repeat coronary arteriography after 7.5 +/- 2.6 months (mean +/- SD), and 31% of lesions have recurred. Fifty-eight percent of patients without recurrence at follow-up continue to have improved symptoms. Treadmill exercise time was significantly prolonged in patients in whom all attempted lesions had been successfully dilated and in those in whom only some lesions were dilated. Our experience suggests that approximately 29% of patients with recurrence of angina following CABG may be suitable for angioplasty.     

Coronary artery bypass surgery and percutaneous transluminal coronary angioplasty in patients with multivessel disease

Since its introduction in the early 1970s, coronary artery bypass grafting (CABG) surgery has been proven to relief anginal symptoms in patients with severe myocardial ischemia. Percutaneous coronary intervention (PCI) was introduced in clinical practice at the end of the 1970s and this treatment has also been established to be effective. PCI has now surpassed CABG as the most common means for treating coronary artery disease (CAD). However, restenosis remains its Achille's heel. Until the mid-1990s, a coronary reintervention was needed in 35% to 40% of the patients. Since then, interventional techniques and technology have evolved with improved success in more complex and anatomical settings, and restenosis has been now consistently decreased to around 20%. Despite all these improvements, the incidence of restenosis, especially in the 1(st) year, is still an important limitation to PCI. The major determinants of restenosis are elastic recoil, negative vessel remodeling and neointimal proliferation as a response to vessel injury induced by angioplasty devices. The use of conventional stents has provided an efficient method to face the first 2 problems, but neointimal proliferation is not affected by stenting. A new approach consists of using the stent as a drug carrier to the target site in order to inhibit restenosis. The first results of utilization of these fascinating drug-eluting stents (DES) to treat relatively simple lesions are very promising, but further analyses for more complex lesions such as those commonly found in daily practice are needed before any definitive conclusions can be made.     

Role of coronary artery bypass surgery after intracoronary streptokinase infusion for myocardial infarction

Intracoronary streptokinase infusion has been shown to improve left ventricular function and reduce hospital mortality in patients with acute myocardial infarction. Adjuvant coronary artery bypass surgery is of value in many of these patients who have recurrent angina, circulatory instability, severe coronary artery occlusive disease, or a high risk of reinfarction. There is little, if any, evidence that immediate coronary artery bypass surgery affects the results adversely—either because of recent myocardial infarction or recent streptokinase infusion, and early operation appears to be a safe and worthwhile modality of treatment in this group of patients with myocardial infarction.