Outcome of acute ST-segment elevation myocardial infarction in patients with prior coronary artery bypass surgery receiving thrombolytic therapyAmerican Heart JournalVolume 141 Number 3 March 2001
Background • The Global Utilization of Streptokinase and Tissue Plasminogen Activator (alteplase) for Occluded Coronary Arteries (GUSTO-I) trial was designed to test the hypothesis that early, sustained infarct-artery patency is associated with better survival in patients with evolving acute MI. The 41,021 study patients included 1784 with prior CABG who were prospectively selected for subgroup analysis.
Methods • Patients were eligible for randomization if they came to a hospital <6 hours after the onset of symptoms, with chest pain lasting ≧20 minutes and accompanied by electrocardiographic (ECG) signs of ≧0.1 mV ST-segment elevation in two or more limb leads or ≧0.2 mV elevation in two or more contiguous precordial leads. Patients with prior CABG were eligible for enrollment.
Randomization and treatment strategies • Randomly assigned all patients to one of four treatment strategies: a.streptokinase with subcutaneous heparin b.streptokinase with intravenous heparin c.accelerated alteplase with intravenous heparin d.combined alteplase and streptokinase with intravenous heparin
Results (1) • Overall, 30-day mortality was significantly higher in patients with prior bypass (10.7% vs 6.7% ). Patients with prior bypass showed a 12.5% relative reduction in 30-day mortality with accelerated alteplase over the streptokinase monotherapies. • As in the study as a whole, the subgroup of patients with prior CABG who received accelerated alteplase had lower 30-day mortality than did patients in the combined streptokinase groups.
Major clinical end points for patients with and without prior bypass surgery, overall and by treatment group Overall Prior bypass, by treatment group Prior bypass(n = 1784) No prior bypass(n = 39,147) Statistical significance SK-SQ(n = 418) SK-IV(n = 428) Alteplase(n = 489) Combo(n = 428) Statistical significance* 24-Hour mortality (%) 3.5 2.6 P = .041 3.8 2.7 3.3 4.2 P = .97 30-Day mortality (%) 10.7 6.7 P < .001 10.1 11.4 9.4 11.9 P = .43 1-year mortality (%) 17.5 9.4 P < .001 18.1 16.9 16.7 18.6 P=.59
Results (2) • In the 62% of patients with prior CABG who underwent coronary angiography, the infarct-related vessel was a native coronary artery in 61.9% and a bypass graft in 38.1% of cases. Patients with prior bypass had more severe infarct-vessel stenoses.
Discussion(1) • At 30 days, the average mortality rate for patients with prior CABG was 10.7% overall, higher than the overall 7.0% mortality for all 41,021 patients enrolled in GUSTO-I. • At the end of the first year, the difference in mortality increased further (17.5% vs 9.4% in patients without prior CABG).
Discussion(2) Optimal treatment of patients with prior CABG As in the main study, the subgroup of patients with prior CABG had the lowest mortality rate at 30 days (9.4%) with accelerated alteplase treatment.
Conclusions(1) • In summary, patients with prior CABG treated with thrombolytic therapy for acute MI have a significantly worse outcome compared with patients without prior CABG. • Patients who have had bypass surgery and who later have an acute MI have more severe infarct-vessel stenoses, whether the infarct vessel is a graft or a native vessel.
Conclusions(2) • Those with prior CABG appear to derive a beneficial effect of treatment with accelerated alteplase compared with streptokinase.
Analysis of Risk Factors for Myocardial Infarction and Cardiac Mortality after Major Vascular Surgery AnesthesiologyVolume 93 Number 1 July 2000
Background • This study was undertaken to identify predictors of PMI and in-hospital death in major vascular surgical patients.
Methods • From the Vascular Surgery Registry (6,948 operations from 1989 through 1997) • The authors analyzed data regarding preoperative cardiac disease and surgical and anesthetic factors to study association with PMI and cardiac death.
Results(1) Predictors of PMI: valvular disease, previous congestive heart failure, emergency surgery, general anesthesia, preoperative history of coronary artery disease, preoperative treatment with beta-blockers, lower preoperative and postoperative hemoglobin concentrations, increased bleeding rate, and lower ejection fraction
Results(2) • Factors increased the odds ratios for cardiac death: age, recent congestive heart failure, type of surgery, emergency surgery, lower intraoperative diastolic blood pressure, new intraoperative ST-T changes, and increased intraoperative use of blood.
Results(3) • Congestive heart failure less than 1 yr before index vascular surgery and increased intraoperative use of blood were associated with cardiac death. • The history of coronary artery bypass grafting reduced the risk of cardiac death in patients with PMI.
Conclusions • Stress of surgery (increased intraoperative bleeding and aortic, peripheral vascular, and emergency surgery) • poor preoperative cardiac functional status (congestive heart failure, lower ejection fraction, diagnosis of coronary artery disease) • preoperative history of coronary artery bypass grafting are the factors that determine perioperative cardiac morbidity and mortality rates.
Heart-type fatty acid binding protein (hFBAP) in the diagnosis of myocardial damage in coronary artery bypass grafting EUR J Cardiothoracic Surgery 01-Jun-2001; 19(6): 859-864
Background • Heart-type fatty acid binding protein: An intracellular molecular engaged in the transport of fatty acid through myocardial cytoplasm and has been used as a marker of myocardial infarction.
Methods • 32 consecutive patients undergoing coronary artery bypass grafting • Serial blood samples were taken preoperatively, before ischemia, 5 and 60 mins after declamping, 1 and 6 h postoperatively and post operative days 1, 2 and 10 and were tested for hFABP, CKMB and TnI.
Results • hFABP levels peaked as early as 1 h after declamping, whereas CKMB and TnI peaked after only 1 h after arrival in the ICU. Patients with perioperative infarction displayed peak levels of CKMB and TnI, indicating the degree of myocardial damage.
Conclusions • hFABP is a rapid marker of perioperative myocardial damage and peaks earlier than CKMB or TnI. The kinetics of marker proteins in serial samples immediately after reperfusion is more suitable for the detection of perioperative myocardial infarction than a fixed cut-off level.