Comparison of some criteria for diagnosing a myocardial infarction after aorto-coronary bypass grafting (CABG)

Early Postoperative Assessment of Coronary Artery Bypass Graft Patency and Anatomy: Value of Contrast-Enhanced 16-MDCT with Retrospectively ECG-Gated Reconstructions

OBJECTIVE

The objective of our study was to assess early postoperative patency and anatomy of off-pump coronary artery bypass grafts (CABGs) using retrospectively ECG-gated MDCT.

CONCLUSION

Retrospectively ECG-gated MDCT is a promising noninvasive technique with which to assess early postoperative patency and anatomy of CABGs.

Intraoperative local fibrinolysis as emergency therapy after early coronary artery bypass thrombosis

OBJECTIVE

Acute graft occlusion early postoperatively after coronary artery bypass grafting (CABG) is a rare but dramatic complication, frequently making resuscitation necessary. Emergency reoperation with reanastomosing of the concerning grafts is the normal procedure to restrict the otherwise unavoidable myocardial damage. Mortality in these cases is up to 50%. Due to this unsatisfying situation, we perform since 1995 in such cases an adjuvant intraoperative intracoronary installed fibrinolysis with recombinant tissue type plasminogen activator (rt-PA; alteplase).

METHODS

Between 1/1994 and 8/1998, 4231 patients underwent CABG. In 18 of these patients, emergency reoperation within the first 12 h after CABG due to clinical signs of acute myocardial infarction was necessary. In nine of the patients (group II) additionally intraoperative rt-PA lysis of the involved vessel/s has been performed. When the peripheral anastomosis was reopened and the thrombotic material was removed, we inserted for this a left atrial-catheter (LA-catheter) of 1.2 mm in diameter, into the coronary artery. Then we administered within 3-5 min, up to 100 mg rt-PA (t1/2: 5-9 min.) locally into the vessel. All patients were treated postoperatively with acetylsalicyl acid (ASA) and heparine.

RESULTS

In group I (n = 9; seven males, two females) without thrombolytic therapy, 78% of the patients (n = 7) could not have been prevented from large myocardial infarction despite emergency reoperation. Three of these patients died during or early after reintervention. In group II with fibrinolytic therapy (n = 9) three of the patients developed Q-wave myocardial infarction following reoperation. None of the patients died. Creatinkinase maximum were in group I significantly higher than in group II (group I: CK = 1254 units/I, CK-MB = 197 units/l; group II: CK = 502 units/l, CK-MB = 61 units/l; P < 0.01). Postoperative bleeding was considerable elevated in both groups. In group I, 832 ml/24 h (375-1420 ml), in group II 1164 ml/24 h (520-1560 ml). Lysis-associated complications were not observed.

CONCLUSIONS

Reoperation of patients with acute thrombotic bypass occlusion after CABG is characterized by a high mortality and morbidity. If additionally fibrinolysis is performed, a sufficient myocardial perfusion seems to be restored. A short half-life in combination with the presented non-systemic application technique of rt-PA seem to prevent unpredictable bleeding. Rt-PA lysis apparently contributes very effectively to the restoration of the macro- and microcirculation within the infarct-related area. Thrombolytic therapy during cardiac surgery with rt-PA is feasible, its application easy and harmful complications are not seen.