title: Relation between flow grade after thrombolytic therapy and the effect of angioplasty on left ventricular function: a prospective randomized trial.
abstract: Recent intervention trials during myocardial infarction demonstrated no benefit from emergency angioplasty after thrombolytic therapy when compared with either delayed percutaneous transluminal coronary angioplasty (PTCA) or a conservative strategy. However, it is possible that subgroups of patients may benefit from early intervention with angioplasty. We performed a prospective randomized trial in patients with a patent infarct-related artery after thrombolytic therapy to determine whether initial flow grade is related to infarct-zone function and whether patients with ineffective reperfusion (greater than 90% stenosis or Thrombolysis in Myocardial Infarction [TIMI] flow less than or equal to 2) might benefit from immediate PTCA. Thrombolytic therapy was administered to 170 patients at a mean of 2.1 +/- 0.5 hours after onset of myocardial infarction. A patent infarct-related artery that was suitable for angioplasty was present in 89 patients who comprised the study group; after randomization, 47 of 50 patients with a patent infarct-related artery had successful emergency PTCA 3.8 +/- 1.5 hours after onset of symptoms, and 39 were scheduled for delayed (18 to 48-hour) PTCA. Reocclusion occurred before the scheduled (delayed) procedure in eight patients (20.5%), and was symptomatic in six. Infarct-region function (by the centerline method) measured initially, before discharge, and at 4 months was similar in both groups; improvement was significant (p less than 0.001) at discharge when compared with initial values with no further change at 4 months. However, patients with ineffective reperfusion had greater hypokinesia initially (p less than 0.05) compared with those with effective reperfusion (less than or equal to 90% stenosis plus TIMI flow 3). Moreover, independent of the timing of PTCA, improvement was greater before discharge in patients with ineffective reperfusion (p less than 0.05) with a trend also evident at 4 months. Importantly, 42 of 51 patients (82%) with a residual lumen less than 0.4 mm after thrombolysis had some improvement in function at discharge; this compared with a previous study in which patients with a similar degree of stenosis (without PTCA) had no improvement. Moreover, reocclusion occurred before scheduled (delayed) PTCA in 37% of patients with greater than 90% stenosis compared with only 5% in those with less than or equal to 90% stenosis (p = 0.02). Thus flow grade is an important determinant of myocardial function in patients with a patent artery after thrombolytic therapy and is predictive both of improvement in wall motion after PTCA and early reocclusion.(ABSTRACT TRUNCATED AT 400 WORDS)
authors.affiliation: Department of Medicine, University of Calgary, Alberta, Canada.
authors.forename: I
authors.initials: I
authors.lastname: Belenkie
authors.forename: M L
authors.initials: ML
authors.lastname: Knudtson
authors.forename: D L
authors.initials: DL
authors.lastname: Roth
authors.forename: J L
authors.initials: JL
authors.lastname: Hansen
authors.forename: M
authors.initials: M
authors.lastname: Traboulsi
authors.forename: C A
authors.initials: CA
authors.lastname: Hall
authors.forename: D
authors.initials: D
authors.lastname: Manyari
authors.forename: N G
authors.initials: NG
authors.lastname: Filipchuck
authors.forename: L P
authors.initials: LP
authors.lastname: Schnurr
authors.forename: T W
authors.initials: TW
authors.lastname: Rosenal
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D006328:Cardiac Catheterization; D003131:Combined Modality Therapy; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D011446:Prospective Studies; D012008:Recurrence; D015912:Thrombolytic Therapy / Q000379:methods; D013997:Time Factors; D016277:Ventricular Function, Left / Q000502:physiology*