Medline ® Abstracts for References 1,2
of 'Predictors of coronary artery reocclusion following fibrinolysis (thrombolysis)'
Consequences of reocclusion after successful reperfusion therapy in acute myocardial infarction. TAMI Study Group.
Ohman EM, Califf RM, Topol EJ, Candela R, Abbottsmith C, Ellis S, Sigmon KN, Kereiakes D, George B, Stack R
To determine the clinical consequences of reocclusion of an infarct-related artery after reperfusion therapy, we evaluated 810 patients with acute myocardial infarction. Patients were admitted into four sequential studies with similar entry criteria in which patency of the infarct-related artery was assessed by coronary arteriography 90 minutes after onset of thrombolytic therapy. Successful reperfusion was established acutely in 733 patients. Thrombolytic therapy included tissue-type plasminogen activator (t-PA) in 517, urokinase in 87, and a combination of t-PA and urokinase in 129 patients. All patients received aspirin, intravenous heparin and nitroglycerin, and diltiazem during the recovery phase. A repeat coronary arteriogram was performed in 88% of patients at a median of 7 days after the onset of symptoms. Reocclusion of the infarct-related artery occurred in 91 patients (12.4%), and 58% of these were symptomatic. Angiographic characteristics at 90 minutes after thrombolytic therapy that were associated with reocclusion compared with sustained coronary artery patency were right coronary infarct-related artery (65% versus 44%, respectively) and Thrombolysis in Myocardial Infarction (TIMI) flow 0 or 1 (21% versus 10%, respectively) before further intervention. Median (interquartile value) degree of stenosis in the infarct-related artery at90 minutes was similar between groups: 99% for reoccluded (value, 90/100%) compared with 95% for patent (value, 80/99%). Patients with reocclusion had similar left ventricular ejection fractions compared with patients with sustained patency at follow-up. However, patients with reocclusion at follow-up had worse infarct-zone function at -2.7 (value, -3.2/-1.8) versus -2.4 (SD/chord) (value, -3.1/-1.3) (p = 0.016). The recovery of both global and infarct-zone function was impaired by reocclusion of the infarct-related artery compared with maintained patency; median delta ejection fraction was -2 compared with 1 (p = 0.006) and median delta infarct-zone wall motion was -0.10 compared with 0.34 SD/chord (p = 0.011), respectively. In addition, patients with reocclusion had more complicated hospital courses and higher in-hospital mortality rates (11.0% versus 4.5%, respectively; p = 0.01). We conclude that reocclusion of the infarct-related artery after successful reperfusion is associated with substantial morbidity and mortality rates. Reocclusion is also detrimental to the functional recovery of both global and infarct-zone regional left ventricular function. Thus, new strategies in the postinfarction period need to be developed to prevent reocclusion of the infarct-related artery.
Department of Medicine, Duke University Medical Center, Durham, NC 27710.
Recurrent ischemia without warning. Analysis of risk factors for in-hospital ischemic events following successful thrombolysis with intravenous tissue plasminogen activator.
Ellis SG, Topol EJ, George BS, Kereiakes DJ, Debowey D, Sigmon KN, Pickel A, Lee KL, Califf RM
Ischemic events after successful thrombolysis have been reported to occur in 18-32% of patients treated for acute myocardial infarction with thrombolytic therapy, and previous studies in which patients received streptokinase suggest that risk of early recurrent ischemia is closely related to the presence of a high-grade residual stenosis. If these events are predictable after intravenous recombinant tissue-plasminogen activator (rt-PA) thrombolytic therapy, then further intervention after its use could be targeted at selected patients. One-hundred ninety-two patients from the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) I and TAMI III trials had successful rt-PA-mediated thrombolysis without immediate coronary angioplasty (PTCA). One-hundred seventy-four of these patients (92%) had prehospital discharge angiography. The mean age was 56 +/- 11 years; 81% were men; the infarct-related artery was the left anterior descending in 76 (39.8%), the left circumflex in 24 (12.6%), and the right coronary artery in 91 (47.6%). Thrombolysis with rt-PA resulted in a residual 73 +/- 13% diameter and 0.95 +/- 0.51 mm stenosis by quantitative coronary arteriography, and Thrombolysis in Myocardial Infarction (TIMI) flow grade 2 in 59.2% and 3 in 40.8% of stenoses as assessed on angiograms obtained 90 minutes after the initiation of rt-PA therapy. Recurrent ischemic events (ischemia requiring emergency percutaneous transluminal coronary angioplasty or urgent bypass surgery, reocclusion of the infarct-related artery, or cardiac death) occurred in 41 patients (21.3%).(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109.