Previous coronary artery bypass grafting as an adverse prognostic factor in unstable angina pectoris

Characteristics and Outcome of Patients ≥75 Years of Age With Prior Coronary Artery Bypass Grafting Admitted for an Acute Coronary Syndrome

The prognostic role of previous coronary artery bypass (CABG) in elderly patients admitted to hospital for an acute coronary syndrome (ACS) is unclear. Therefore, the aim of this study was to compare the prognosis of patients aged ≥75 years admitted for an ACS with or without previous history of CABG. The primary outcome of the study was a composite of overall mortality, recurrent nonfatal myocardial infarction, nonfatal stroke, and rehospitalization for heart failure at 1-year follow-up. We included 2,253 ACS patients, aged 81 (78 to 85) years enrolled in 3 multicenter studies (the Italian Elderly ACS study, the LADIES ACS study, and the Elderly ACS 2 randomised trial) - 178 (7.9%) with previous CABG, 2,075 (92.1%) without. Patients with previous CABG had a higher burden of cardiovascular risk factors, lower ejection fraction, and higher creatinine values on admission. However, both at univariate analysis and after adjustment for the most relevant covariates (sex, age, previous myocardial infarction, type of ACS, left ventricular ejection fraction, and serum creatinine on admission), previous CABG did not show any statistically significant association with 1-year outcome (adjusted hazard ratio 0.85; 95% confidence interval 0.61 to 1.19; p = 0.353). In conclusion, our study suggests that elderly ACS patients with previous CABG have worse basal clinical characteristics. Nevertheless, in a broad cohort of patients mostly treated with percutaneous coronary intervention during the index event, previous CABG did not confer independent additional risk of major adverse cardiovascular events at 1-year follow-up.

Nicorandil effects on platelet function, Hs-CRP, MMP-9 and myocardial antioxidation in patients with unstable angina

Nicorandil effects on platelet activation and myocardial antioxidant function in patients with unstable angina were studied. A total of 157 patients with unstable angina in the First People's Hospital of Foshan were selected and divided into experimental and control group. Patients in experimental group were treated with conventional drugs and nicorandil (15 min/day), t.i.d., for 21 days as one course of treatment, while those in control group were treated with conventional drugs. After treatment, serum indexes were detected and compared between the two groups of patients. Compared with that in control group, the platelet function of patients in the experimental group was significantly improved, and there was a statistically significant difference (P<0.05). Serum anti-oxidation factors in both groups were increased after treatment, and they were increased more significantly in experimental group (P<0.05). Serum inflammatory factors, high-sensitivity C-reactive protein and matrix metalloproteinase-9, also declined significantly in the experimental group. Nicorandil reduces inflammatory response and promotes stability of myocardial function in the treatment of unstable angina.

Outcomes of patients with prior coronary artery bypass graft who present with acute coronary syndrome

Generally, patients with prior coronary artery bypass graft (CABG) are often under-represented in acute coronary syndrome (ACS) clinical trials. Nevertheless, there is growing global attention concerning their short- and long-term prognosis. Some reports suggest prior CABG as an independent risk factor for increased mortality, while others report an equal or a more favorable prognosis despite their adverse baseline clinical characteristics. The reasons for this 'risk-mortality paradox' need to be further evaluated. More recent reports showed a significant reduction in in-hospital morbidity and mortality over a 20-year period of follow up that may be attributed to the improvement in surgical CABG techniques and increased use of evidence-based therapies over the past two decades. In the current review we discuss the available literature regarding outcomes of prior CABG patients who are presenting with ACS.

Effect of ticagrelor on the outcomes of patients with prior coronary artery bypass graft surgery: insights from the PLATelet inhibition and patient outcomes (PLATO) trial

BACKGROUND

Patients with prior coronary artery bypass graft surgery (CABG) who present with an acute coronary syndrome have a high risk for recurrent events. Whether intensive antiplatelet therapy with ticagrelor might be beneficial compared with clopidogrel is unknown. In this substudy of the PLATO trial, we studied the effects of randomized treatment dependent on history of CABG.

METHODS

Patients participating in PLATO were classified according to whether they had undergone prior CABG. The trial's primary and secondary end points were compared using Cox proportional hazards regression.

RESULTS

Of the 18,613 study patients, 1,133 (6.1%) had prior CABG. Prior-CABG patients had more high-risk characteristics at study entry and a 2-fold increase in clinical events during follow-up, but less major bleeding. The primary end point (composite of cardiovascular death, myocardial infarction, and stroke) was reduced to a similar extent by ticagrelor among patients with (19.6% vs 21.4%; adjusted hazard ratio [HR], 0.91 [0.67, 1.24]) and without (9.2% vs 11.0%; adjusted HR, 0.86 [0.77, 0.96]; P(interaction) = .73) prior CABG. Major bleeding was similar with ticagrelor versus clopidogrel among patients with (8.1% vs 8.7%; adjusted HR, 0.89 [0.55, 1.47]) and without (11.8% vs 11.4%; HR, 1.08 [0.98, 1.20]; P(interaction) = .46) prior CABG.

CONCLUSIONS

Prior-CABG patients presenting with acute coronary syndrome are a high-risk cohort for death and recurrent cardiovascular events but have a lower risk for major bleeding. Similar to the results in no-prior-CABG patients, ticagrelor was associated with a reduction in ischemic events without an increase in major bleeding.

Acute coronary syndrome in patients with prior coronary artery bypass surgery: observations from a 20-year registry in a middle-eastern country

Objectives

Clinical characteristics and trends in the outcome of acute coronary syndrome (ACS) in patients with prior coronary artery bypass graft surgery (CABG) are unclear. The aim of this study was to evaluate clinical characteristics, in-hospital treatment, and outcomes in patients presented with ACS with or without a history of prior CABG over 2 decades.

Methods

Data were derived from hospital-based study for collected data from 1991 through 2010 of patients hospitalized with ACS in Doha, Qatar. Data were analyzed according to their history of prior CABG. Baseline clinical characteristics, in-hospital treatment, and outcome were compared.

Results

A total 16,750 consecutive patients with ACS were studied, of which 693 (4.1%) had prior CABG. Patients with prior CABG were older (mean 60.5±11 vs. 53±12 years; P = 0.001), more likely to be females and have more cardiovascular risk factors than the non-CABG group. Prior CABG patients had larger infarct size, were less likely to receive reperfusion therapy, early invasive therapy and more likely to receive evidence-based therapies when compared to non-CABG patients. In-hospital mortality and stroke rates were comparable between the 2 groups. Over 2 decades, there was reduction in the in-hospital mortality rates and stroke rates in both groups (CABG, death; 13.2% to 4%, stroke; 1.9% to 0.0%, non-CABG, death; 10% to 3.2%, stroke 1.0% to 0.1%; all, p = 0.001).

Conclusion

Significant reduction in-hospital morbidity and mortality among ACS patients with prior CABG over a 20-year period.

Association of prior coronary artery bypass graft surgery with quality of care of patients with non-ST-segment elevation myocardial infarction: a report from the National Cardiovascular Data Registry Acute Coronary Treatment and Intervention Outcomes Network Registry-Get With the Guidelines

BACKGROUND

The American College of Cardiology/American Health Association guidelines recommend both an early invasive strategy and administration of antiplatelet/anticoagulant therapy for high-risk patients in the absence of contraindications. Little is known about adherence to guideline recommendations in patients with prior coronary artery bypass graft (CABG) surgery presenting with non-ST-segment elevation myocardial infarction (NSTEMI).

METHODS

We analyzed 47,557 patients with NSTEMI in the 2007-2008 National Cardiovascular Data Registry Acute Coronary Treatment and Intervention Outcomes Network Registry-Get With The Guidelines. Treatment patterns were compared between patients with and without prior CABG surgery. Multivariable regression with generalized estimating equations evaluated the association between prior CABG and in-hospital outcomes.

RESULTS

In this study, 8,790 NSTEMI patients (18.5%) had a history of CABG surgery. Prior CABG surgery was associated with a significantly lower adjusted likelihood of early cardiac catheterization (adjusted odds ratio [OR] 0.88, 95% CI 0.83-0.92), higher rates of short-term clopidogrel use (adjusted OR 1.08, 95% CI 1.02-1.14), and comparable use of anticoagulant therapy (adjusted OR 0.96, 95% CI 0.88-1.04). Adjusted risks of bleeding and in-hospital mortality did not differ significantly between the 2 groups (adjusted ORs 1.00, 95% CI 0.92-1.11 and 0.99, 95% CI 0.87-1.11, respectively).

CONCLUSIONS

Patients with prior CABG surgery presenting with NSTEMI are often felt to be at high risk for adverse outcomes and therefore require aggressive treatment. Our study indicates that they are less likely to undergo guideline-recommended early cardiac catheterization but equally or more likely to receive guideline-recommended antiplatelet and anticoagulant therapy. This risk-treatment paradox, however, does not appear to negatively influence short-term clinical outcomes.

Management patterns of non-ST segment elevation acute coronary syndromes in relation to prior coronary revascularization

BACKGROUND

Contemporary guidelines support an early invasive strategy for non-ST elevation acute coronary syndrome (NSTE-ACS) patients who had prior coronary revascularization. However, little is known about the management pattern of these patients in "real world."

METHODS

We analyzed 3 consecutive Canadian registries (ACS I, ACS II, and Global Registry of Acute Coronary Events [GRACE]/expanded-GRACE) that recruited 12,483 NSTE-ACS patients from June 1999 to December 2007. We stratified the study population according to prior coronary revascularization status into 4 groups and compared their clinical characteristics, in-hospital use of medications, and cardiac procedures.

RESULTS

Of the 12,483 NSTE-ACS patients, 71.2% had no prior revascularization, 14.2% had percutaneous coronary intervention (PCI) only, 9.5% had coronary artery bypass graft surgery (CABG) only, and 5% had both PCI and CABG. Compared to their counterparts without prior revascularization, patients with previous PCI and/or CABG were more likely to be male, to have diabetes, myocardial infarction, and heart failure but less likely to have ST-segment deviation or positive cardiac biomarker on presentation. Early use of evidence-based medications was higher among patients with previous PCI only and lower among patients with previous CABG only. After adjusting for possible confounders including GRACE risk score, prior PCI was independently associated with in-hospital use of cardiac catheterization (adjusted odds ratio [OR] 1.18, 95% CI 1.04-1.34, P = .008). In contrast, previous CABG was an independent negative predictor (adjusted OR .77, 95% CI 0.68-0.87, P < .001). There was no significant interaction (P = .93) between previous PCI and CABG.

CONCLUSIONS

The NSTE-ACS patients with previous PCI were more likely to be treated invasively. Conversely, patients with prior CABG less frequently received invasive therapy. Future studies should determine the appropriateness of this treatment discrepancy.

Outcomes of patients with acute coronary syndrome and previous coronary artery bypass grafting (from the Pravastatin or Atorvastatin Evaluation and Infection Therapy [PROVE IT-TIMI 22] and the Aggrastat to Zocor [A to Z] trials)

We examined the effects of intensive statin therapy in patients with acute coronary syndromes (ACSs) and previous coronary artery bypass graft surgery (CABG) participating in the Pravastatin or Atorvastatin Evaluation and Infection Therapy-Thrombolysis In Myocardial Infarction 22 (PROVE-IT TIMI 22) and the Aggrastat to Zocor (A to Z) trials. Of the 8,655 patients enrolled in PROVE IT-TIMI 22 or A to Z, 640 (7.4%) had undergone CABG before enrollment. After a median follow-up of 2 years, compared with patients without previous CABG, those with previous CABG had a higher risk of cardiovascular death (6.2% vs 2.8%), myocardial infarction (14.2% vs 6.6%), and readmission for ACS (7.9% vs 4.4%, p <0.001 for all comparisons) but a lower rate of repeat coronary revascularization (22.7% vs 26.9%, p = 0.01). Compared with moderate statin therapy, intensive statin therapy appeared to decrease the composite of cardiovascular death, myocardial infarction, stoke, and readmission for an ACS (A to Z primary end point) to a similar extent in patients with (26.1% vs 21.6%, hazard ratio 0.84, p = 0.27) and without (13.9% vs 12.0%, hazard ratio 0.86, p = 0.016) previous CABG, although the decrease was not statistically significant in the previous CABG group, likely due to the small number of patients with previous CABG. In conclusion, compared with patients with ACS without previous CABG, those with previous CABG have a higher risk for adverse cardiac events and may derive similar benefit from intensive statin therapy.

CABG-procedures in patients with pretreatment with the GPIIb/IIIa-receptor antagonist tirofiban (Aggrastat©): Modification of perioperative management?

In order to investigate the effects of tirofiban administration in cardiac surgery all patients undergoing coronary artery bypass grafting (CABG) which received this drug preoperatively between 1/2002 and 6/2005 (n=232) were studied. Three groups regarding the perioperative administration of antifibrinolytic drugs were compared: group A=controls (n=70), group B=aprotinin (n=110), group C=tranexamic acid (n=52) Furthermore we could differ the patients depending on the time when tirofiban was stopped (<2 h, 2-4 h, >4 h preoperatively). The postoperative blood loss was significantly higher in all tirofiban-patients (A-C) compared to a group of CABG-patients without tirofiban. The best results concerning blood loss, transfusion of red cell concentrates (rcc), fresh frozen plasma (ffp) and incidence of re-sternotomy could be found in patients with aprotinin. A further significant improvement could be seen in patients who received platelets, intraoperative hemofiltration and in which tirofiban was stopped >4 h preoperatively. We conclude that by early presurgical discontinuing of tirofiban-therapy and slight modifications of the perioperative management bleeding complications can significantly be reduced.

Early invasive strategy improves outcomes in patients with acute coronary syndrome with previous coronary artery bypass graft surgery: a report from TACTICS-TIMI 18

BACKGROUND

Patients with previous coronary artery bypass graft surgery (CABG) have been classified as a high-risk subset of patients who experience non-ST elevation acute coronary syndrome (ACS). Recent studies suggest that an early invasive strategy is beneficial in moderate- and high-risk patients with non-ST elevation ACS. We hypothesized that an early invasive strategy is associated with improved outcomes in patients with non-ST elevation ACS with prior CABG.

METHODS AND RESULTS

In the Treat Angina with Aggrastat and determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis in Myocardial Infarction 18 trial (TACTICS-TIMI 18), 2220 patients with non-ST segment elevation ACS were randomized to an early invasive or conservative (selectively invasive) strategy. All patients were treated with aspirin, heparin, and tirofiban. Four hundred eighty-four (22%) of these patients had undergone CABG before enrollment. We analyzed whether patients with previous CABG had different 6-month outcomes and whether an early invasive strategy was associated with an improvement in long-term outcomes. Prior CABG was associated with a higher risk of adverse outcomes by 6 months, including a higher rate of readmission for ACS (17.4% vs 11.0%, P < 0.001) and a higher incidence of the composite end point of death, myocardial infarction, or rehospitalization for ACS (22.3% vs 16.4%, P = 0.002). There was a trend toward a higher incidence of myocardial infarction (7.1% vs 5.3%, P = 0.051). An early invasive strategy was associated with a reduction in the composite of death or myocardial infarction (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.31-1.0; P = 0.089) and a significant reduction in the incidence of myocardial infarction at 6 months (OR, 0.44; 95% CI, 0.21-0.93; P=0.032).

CONCLUSIONS

Patients with non-ST segment elevation ACS who have had previous CABG are a high-risk subset. An early invasive strategy reduces risk of myocardial infarction in this high-risk group.

Outcomes of patients with acute coronary syndromes and prior percutaneous coronary intervention: a pooled analysis of three randomized clinical trials

AIMS

We sought to characterize the outcomes of patients with a prior percutaneous coronary intervention (PCI) who presented with a non-ST-segment elevation acute coronary syndrome (ACS).

METHODS AND RESULTS

We analysed the 30 and 180 day outcomes of 3012 patients with prior PCI and 21 154 patients without prior PCI enrolled in three randomized ACS trials (GUSTO IIb, PURSUIT, and PARAGON-B). The median (25th, 75th percentile) interval between the prior PCI and randomization was 647 (123, 1585) days. Patients with prior PCI had significantly more adverse baseline clinical characteristics, left ventricular dysfunction, and multi-vessel coronary artery disease. After adjusting for baseline characteristics and treatment, we found that patients with prior PCI had a significantly lower mortality rate at 30 days [hazard ratio (HR), 0.60; 95% confidence interval (CI), 0.45-0.80; P=0.0006] and 180 days (HR, 0.81; 95% CI, 0.66-0.98; P=0.029). However, no difference was observed in the composite of death or myocardial infarction (MI) at 30 days (HR, 0.95; 95% CI, 0.83-1.08; P=0.42) or 180 days (HR, 1.01; 95% CI, 0.90-1.13; P=0.90). Patients with prior PCI had a higher rate of MI at 180 days (13.3 vs. 12.0%; P=0.045). Prior-PCI patients had lower incidences of in-hospital cardiogenic shock, congestive heart failure (CHF), and atrial fibrillation.

CONCLUSION

Patients with prior PCI who present with non-ST-segment elevation ACS have a lower mortality rate than those without prior PCI.

Tirofiban therapy for patients with acute coronary syndromes and prior coronary artery bypass grafting in the PRISM-PLUS trial

The role of glycoprotein IIb/IIIa platelet receptor antagonist therapy for patients with an acute coronary syndrome (ACS) and a history of coronary artery bypass grafting (CABG) remains incompletely defined. We examined the outcomes of patients with an ACS and prior CABG who were treated with tirofiban versus placebo among subjects with prior CABG in the Platelet Receptor Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Signs and Symptoms (PRISM-PLUS) trial. Of 1,570 patients treated with tirofiban plus heparin (n = 773) or heparin alone (n = 797), 231 had prior CABG. Compared with patients without prior CABG, those with prior CABG were more likely to have risk factors for a complicated ACS course, including severe coronary artery disease and heart failure (all p <0.0001), typically had clinical predictors of benefit from tirofiban, such as ST-segment depression (p = 0.01) or a TIMI risk score >or=4 (p <0.001), and were more likely to die or have a myocardial infarction or refractory ischemia at all time points examined (p <0.0001). Among patients with prior CABG, decreases in the incidence of death, myocardial infarction, or refractory ischemia with tirofiban and heparin versus heparin alone were noted at 7 and 30 days (7 days: 16.9% vs 29.0%, p = 0.035; 30 days: 25.0% vs 40.2%, p = 0.015). Trends toward a decrease in death, myocardial infarction, and refractory ischemia with tirofiban and heparin versus heparin alone in the prior CABG subgroup were noted at 48 hours and 180 days (48 hours: 6.5% vs 14.0%, p = 0.09; 180 days: 37.1% vs 48.6%, p = 0.057). Bleeding rates were similar in patients with and without prior CABG. Tirofiban was well tolerated and tended to decrease the considerable risk for ischemic ACS complications in patients with prior CABG.

Outcomes of patients with acute coronary syndromes and prior coronary artery bypass grafting: results from the platelet glycoprotein IIb/IIIa in unstable angina: receptor suppression using integrilin therapy (PURSUIT) trial

BACKGROUND

Patients with prior CABG with a subsequent non-ST-segment elevation acute coronary syndrome (ACS) pose an increasingly important clinical problem. Although GP IIb/IIIa inhibitors have improved the outcome of patients with ACS, their efficacy in patients with prior CABG has not been previously evaluated. Methods and Results- We analyzed the 30- and 180-day outcomes of patients with prior CABG enrolled in the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial. In this trial, which evaluated the efficacy of eptifibatide in patients with ACS, 1134 patients (12%) with prior CABG and 8321 without prior CABG were enrolled. After adjusting for differences in baseline characteristics and treatment, patients with prior CABG had a significantly higher mortality rates at 30 days (hazard ratio [HR], 1.45 [95% CI, 1.06 to 1.98]; P=0.019) and at 180 days (HR, 1.32 [95% CI, 1.04 to 1.67]; P=0.021). At 30 days, there was a similar effect on the primary end point of death or myocardial infarction in the eptifibatide group versus the placebo group in prior CABG patients (unadjusted HR, 0.90 [95% CI, 0.67 to 1.20]) and in patients without a history of CABG (unadjusted HR, 0.89 [95% CI, 0.80 to 0.99]).

CONCLUSIONS

Patients with prior CABG with non-ST-segment elevation ACS have a significantly worse prognosis than do patients without a history of CABG. The treatment effect of eptifibatide in the prior CABG group was similar to the effect seen in patients without prior CABG.

Aspirin, warfarin, or the combination for secondary prevention of coronary events in patients with acute coronary syndromes and prior coronary artery bypass surgery

BACKGROUND

Patients with a non-ST-elevation acute coronary syndrome and prior CABG are at high risk of a recurrent ischemic event despite aspirin therapy. This trial investigated the potential benefit of secondary prevention with warfarin.

METHODS AND RESULTS

In a double-blind randomized trial, 135 patients with unstable angina or non-ST-segment elevation myocardial infarction, with prior CABG, and who were poor candidates for a revascularization procedure received therapy with aspirin and placebo+warfarin, warfarin and placebo+aspirin, or aspirin and warfarin for 12 months. Warfarin was titrated to an international normalized ratio of 2.0 to 2.5. The primary end point (death or myocardial infarction or unstable angina requiring hospitalization 1 year after randomization) occurred in 14.6% of the patients in the warfarin-alone group, in 11.5% of patients in the aspirin-alone group, and in 11.3% of patients randomized to the combination therapy (P=0.76). Subgroup analyses by risk features provided no indications that warfarin alone or in combination with aspirin could be of benefit over aspirin alone. Bleeding was more frequent in the 2 groups of patients administered warfarin.

CONCLUSIONS

Moderate-intensity oral anticoagulation alone or combined with low-dose aspirin does not appear to be superior to low-dose aspirin in the prevention of recurrent ischemic events in patients with non-ST-elevation acute coronary syndromes and previous CABG.

Comparison of percutaneous interventions for unstable angina pectoris in patients with and without previous coronary artery bypass grafting

An increasing number of patients who have undergone previous coronary artery bypass grafting (CABG) are referred for percutaneous coronary revascularization. We identified patients who underwent percutaneous intervention for unstable angina from 1990 to 1998 at our institution and assigned them into 2 groups based on whether or not they had undergone previous CABG. There were 1,431 patients with and 4,629 patients without previous CABG. Previous CABG patients were older, had more atherosclerotic risk factors, more heart failure, lower ejection fraction, more multivessel disease, more multilesion treatment, more complex lesions, and less complete revascularization. Adjusting for baseline differences, previous CABG was associated with worse long-term mortality (RR 1.47, 95% confidence intervals [CI] 1.22 to 1.77, p < 0.001) and death, myocardial infarction, and/or revascularization (RR 1.16, 95% CI 1.04 to 1.30, p = 0.01); treatment of native lesions in patients with previous CABG versus treatment of vein graft lesions was associated with a reduction in this composite end point (RR 0.75, 95% CI 0.65 to 0.87, p < 0.001). Post-CABG patients treated between 1995 and 1998 had lower long-term mortality (RR 0.76, 95% CI 0.59 to 0.99, p = 0.04) and death, myocardial infarction, and/or revascularization (RR 0.76, 95% CI 0.66 to 0.88, p < 0.001) compared with those treated between 1990 and 1994. Thus, in patients with unstable angina referred for percutaneous revascularization, previous CABG is associated with reduced event-free survival, although the outcome of post-CABG patients treated from 1995 to 1998 is superior to that observed in patients treated from 1990 to 1994. In patients who underwent previous CABG, treatment of native lesions affords better long-term outcome than vein graft intervention.

Angiographic features of vein grafts versus ungrafted coronary arteries in patients with unstable angina and previous bypass surgery

OBJECTIVES

The aim of the study was to compare the angiographic features of culprit coronary lesions located in grafts with those in native coronary arteries in patients with unstable angina and previous coronary artery bypass graft surgery (CABG).

BACKGROUND

Deterioration of angina in patients with previous CABG is usually due to progression of atherosclerosis in coronary arteries or in vein grafts, but the relative importance of graft versus native coronary artery disease as well as the morphologic features of the culprit lesions in unstable angina have not been systematically assessed.

METHODS

Disease progression and angiographic features of vein grafts and ungrafted and grafted coronary arteries were assessed in 95 consecutive patients admitted with unstable angina or non-Q wave myocardial infarction with CABG > 6 months previously. All patients were receiving aspirin and heparin, and 46 had received streptokinase during the acute phase in a doubleblind, placebo-controlled study. Coronary and vein angiography was performed within 8 days after admission (mean [+/- SD] 5 +/- 2 days). The most recent angiogram served to assess disease progression by quantitative angiography.

RESULTS

The culprit lesion was located in a vein graft in 51 patients, an ungrafted coronary artery in 17 and a grafted artery (proximal and distal to the site of graft insertion) in 9 and was of undetermined site in the remaining 18. The proportion of grafts accounting for acute disease increased to 85% with CABG > or = 5 years. Total occlusion occurred in 25 vein grafts and 4 ungrafted coronary arteries (49% vs. 24%, p = 0.02). Intravessel thrombus was found in 18 culprit vein grafts but in only 2 ungrafted coronary arteries (37% vs. 12%, p = 0.04). Both intravessel thrombus and total occlusion were demonstrated in six culprit vein grafts but in none of the ungrafted coronary arteries (12% vs. 0%, p = NS). The prevalence of total occlusion and thrombus was not influenced by trial medication, streptokinase or placebo.

CONCLUSIONS

Unstable angina in patients with previous CABG is most often due to graft disease and is associated with more frequent thrombi that are more refractory to medical therapy.

Comparison of outcome of patients with unstable angina and non-Q-wave acute myocardial infarction with and without prior coronary artery bypass grafting (Thrombolysis in Myocardial Ischemia III Registry)

The aim of this study was to characterize patients with and without prior coronary artery bypass grafting (CABG) among a prospectively identified cohort of patients presenting with unstable angina or non-Q-wave myocardial infarction. Patients in the Thrombolysis in Myocardial Infarction phase III Registry Prospective Study presented within 96 hours of an episode of unstable angina or non-Q-wave acute myocardial infarction. Of 2,048 patients, 336 (16.4%) had prior CABG. Compared with those without prior CABG, patients were the same age, but were more likely to be men, white, diabetic, have a history of angina or myocardial infarction, to have received anti-ischemic medications in the prior week, and to receive intravenous heparin or nitroglycerin, or both, during hospitalization. They were equally likely to undergo coronary angioplasty or CABG. Death or nonfatal myocardial infarction occurred by day 10 in 4.5% of patients with prior CABG and 2.8% of patients without prior CABG (p = 0.11); and by day 42 in 7.7% and 5.1%, respectively (p = 0.03). The composite of death, myocardial infarction, or recurrent ischemia at 1 year was more common among patients with prior CABG (39.3% vs 30.2%, p = 0.002). By multiple logistic regression, prior CABG was not independently associated with the occurrence of death or myocardial infarction, or the composite of death, myocardial infarction, or recurrent ischemia either at 6 weeks or at 1 year. The likelihood of recurrent ischemic events is greater among patients with than without prior CABG, but is not likely explained by differences in baseline or treatment characteristics which reflect the degree of underlying cardiac disease.

Recurrence of angina after coronary artery bypass surgery: predictors and prognosis (CASS Registry). Coronary Artery Surgery Study

OBJECTIVES

This study sought to define the predictors and prognosis of postoperative angina in patients undergoing coronary artery bypass surgery.

BACKGROUND

Angina recurs in the first postoperative year in 20% to 30% of patients after coronary artery bypass surgery. The Coronary Artery Surgery Study Registry provides an opportunity to study the predictors and prognosis of postoperative angina in a large sample.

METHODS

All patients with isolated coronary artery bypass surgery in the registry were identified, and anginal status was determined on a yearly basis. The influence of angina on mortality, recurrent myocardial infarction and need for reoperation was determined.

RESULTS

Angina recurred in the first year in 24% of patients and by the sixth year in 40%. The significant predictors in a multivariate analysis were minimal coronary artery disease, preoperative angina, use of vein grafts only, previous myocardial infarction, incomplete revascularization, female gender, smoking and younger age. In subsequent years important predictors were angina in the first postoperative year, female gender, younger age and incomplete revascularization. The presence of angina in the first postoperative year was associated with more frequent myocardial infarction (p = 0.04) and greater need for reoperation (p = 0.003) but did not affect survival during the 6-year follow-up period.

CONCLUSIONS

These findings show that the predictors of postoperative angina are features that are or could be predicted before bypass surgery. Thus, patients with these features before bypass surgery could be advised that they would be more likely to experience postoperative angina than those without these features. Postoperative angina is associated with an increased risk of late myocardial infarction and reoperation.

A critical perspective on coronary artery disease and coronary bypass surgery

This paper examines coronary artery disease and coronary artery bypass graft (CABG) surgery from a critical medical anthropological perspective. It explores the issue of why an expensive, individualistic, and mechanistic treatment for the symptoms of coronary artery disease (CABG surgery) has come to be so widely used to treat a condition which is so clearly related to occupational, social and environmental stresses and to behavioral factors. The paper also addresses the issue of why CABG surgery has proliferated in the absence of firm evidence from controlled studies that it is an effective long-term mode of treatment for many patients with this disease. Through this analysis of the growth and continued overuse of CABG surgery the social nature of biomedical knowledge and the socio-cultural, political and economic nature of biomedical decision making are revealed.

Aspirin, heparin, or both to treat acute unstable angina

We tested the usefulness of aspirin (325 mg twice daily), heparin (1000 units per hour by intravenous infusion), and a combination of the two in the early management of acute unstable angina pectoris in a double-blind, randomized, placebo-controlled trial involving 479 patients. The patients entered the study as soon as possible after hospital admission (at a mean [+/- SD] of 7.9 +/- 8.0 hours after the last episode of pain), and the study was ended after 6 +/- 3 days, when definitive therapy had been selected. Major end points--refractory angina, myocardial infarction, and death--occurred in 23, 12, and 1.7 percent of the 118 patients receiving placebo, respectively. Heparin was associated with a decrease in the occurrence of refractory angina (P = 0.002). The incidence of myocardial infarction was significantly reduced in the groups receiving aspirin (3 percent; P = 0.01), heparin (0.8 percent; P less than 0.001), and aspirin plus heparin (1.6 percent, P = 0.003), and no deaths occurred in these groups. There were too few deaths overall to permit evaluation of the effect of treatment on this end point. The combination of aspirin and heparin had no greater protective effect than heparin alone but was associated with slightly more serious bleeding (3.3 vs. 1.7 percent). We conclude that in the acute phase of unstable angina, either aspirin or heparin treatment is associated with a reduced incidence of myocardial infarction, and there is a trend favoring heparin over aspirin. Heparin treatment is also associated with a reduced incidence of refractory angina.