Early and late results of operation after thrombolytic therapy for acute myocardial infarction

The impact of preoperative thrombolysis on long-term survival after coronary artery bypass grafting

BACKGROUND

Coronary artery bypass grafting (CABG) is frequently used after thrombolytic therapy. However, there is little information regarding long-term survival in this setting. The purpose of the present study was to compare the long-term survival of patients subjected to CABG after thrombolysis to those without thrombolysis.

METHODS AND RESULTS

We studied 3760 consecutive patients with isolated CABG between 1992 and 2002. CABG patients without thrombolysis were compared with those who were treated with thrombolysis within 7 days before CABG. Groups were compared by Cox proportional hazard models and Kaplan-Meier survival plots. The propensity for thrombolysis was determined by logistic regression analysis, and each patient with thrombolysis was then matched to 5 patients without thrombolysis. One hundred ninety-six patients (5.2%) were treated with thrombolysis. Patients with thrombolysis were more likely to be male, younger, and with higher rates of unstable angina, emergency operation, recent or transmural myocardial infarction, preoperative intraaortic balloon pump, hemodynamic instability, shock, intravenous nitroglycerine, left-ventricular hypertrophy, sustained ventricular arrhythmia, and higher EuroSCORE. There were no differences in early outcome between matched groups, but the 5-year actuarial survival was higher in patients with thrombolysis (90.3+/-2.2% versus 78.5+/-1.6%; P=0.0007). After adjustment for all factors, the hazard ratio of long-term mortality for patients with thrombolysis was 0.54 (95% CI, 0.36 to 0.81; P=0.003) and, if deaths during the first 12 months were excluded, 0.46 (95% CI, 0.27 to 0.76; P=0.003).

CONCLUSIONS

Patients subjected to CABG within 7 days after thrombolysis demonstrated increased long-term survival.

Results of primary angioplasty for acute myocardial infarction in patients with multivessel coronary artery disease

The influence of multivessel coronary artery disease on the outcome of reperfusion therapy for myocardial infarction has not been fully characterized. Direct coronary angioplasty without antecedent thrombolytic therapy was performed during evolving myocardial infarction in 285 patients with multivessel coronary artery disease at 5.2 +/- 4.2 h after the onset of chest pain. Two vessel disease was present in 163 patients (57%) and three vessel disease in 122 (43%). An anterior infarct was present in 123 patients (43%), cardiogenic shock in 33 (12%) and age greater than or equal to 70 years in 59 (21%). Angioplasty of the infarct-related vessel was successful in 256 patients (90%), including 92% with two vessel and 88% with three vessel disease (p = NS). Emergency bypass surgery was needed in six patients (2%). In-hospital death occurred in 33 patients (12%), including 13 with two vessel and 20 with three vessel disease (p less than 0.05). The mortality rate was only 4% in the subgroup of 101 patients who met entry criteria for thrombolytic trials. The in-hospital mortality rate was 45% in patients in shock and 7% in patients not in shock (p less than 0.01). Logistic regression analysis identified shock and age greater than or equal to 70 years as independently associated with in-hospital death. In 135 patients who underwent predischarge left ventriculography, global ejection fraction increased from 50% to 57% (p less than 0.001) and regional wall motion in the infarct zone improved in 59% of patients. Follow-up data were available in 251 patients (99%) at a mean of 35 +/- 19 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Management of the patient following coronary thrombolysis

Myocardial salvage can be maximized by the early institution of thrombolytic therapy and aspirin. Certain patients may benefit from the administration of intravenous heparin, beta blockers, or nitroglycerin. The routine use of percutaneous transluminal coronary angioplasty (PTCA) or calcium-channel blockers does not appear to be warranted. Recurrent myocardial ischemia should be vigorously treated with medical therapy and there may be value in cardiac catheterization, followed by PTCA or bypass surgery, depending upon the extent of myocardium at risk and the underlying coronary anatomy. Long-term morbidity and mortality may be reduced by instituting aspirin and beta blockers as well as by modifying risk factors. There is no evidence for the long-term benefit from any calcium-channel blocker. Oral anticoagulation may be warranted in those patients with a mural thrombus, congestive heart failure, or atrial fibrillation. ACE inhibitors may be of value in the presence of left ventricular dysfunction and certainly in the presence of symptomatic congestive heart failure. Antiarrhythmic therapy is generally indicated only for symptomatic or life-threatening arrhythmias. Residual myocardial ischemia should be sought by exercise testing, and those patients with poor exercise tolerance generally warrant cardiac catheterization in consideration for revascularization.

Revascularization after thrombolytic therapy for acute myocardial infarction: an analysis of 573 patients

From October, 1981, to January, 1987, at our center, 891 patients received streptokinase within 6 hours of acute myocardial infarction. A total of 318 patients were treated medically, while 388 patients (43.5%) underwent coronary artery bypass grafting (CABG) alone and 185 (20.7%) were treated with percutaneous coronary angioplasty (PTCA). Subsequent CABG was performed in 37 of 185 PTCA patients after unsuccessful angioplasty. Group characteristics were similar. However, multiple-vessel coronary artery disease was present in 70.3% of CABG patients compared with 24.1% in the PTCA groups. Procedure mortality was 3.6% for CABG alone, 5.4% for PTCA alone, and 13.5% for the combined angioplasty and operation group (p less than 0.05 compared with CABG). All deaths in the PTCA group with subsequent CABG occurred in those patients taken emergently to CABG (5 of 20 patients). We conclude that with proper patient selection both forms of revascularization are safe and effective. However, emergency coronary bypass surgery in the event of failed angioplasty has a high risk.