Importance of time to reperfusion for 30-day and late survival and recovery of left ventricular function after primary angioplasty for acute myocardial infarction.
OBJECTIVE
The purpose of this study was to evaluate the importance of time to reperfusion for outcomes after primary angioplasty for acute myocardial infarction.


BACKGROUND
Survival benefit of thrombolytic therapy for acute myocardial infarction is strongly dependent on time to treatment. Recent observations suggest that time to treatment may be less important for survival with primary angioplasty.


METHODS
Consecutive patients (n=1,352) with acute myocardial infarction treated with primary angioplasty were followed for up to 13 years. Paired acute and follow-up ejection fraction data were obtained at cardiac catheterization in 606 patients.


RESULTS
Reperfusion was achieved within 2 h in 164 patients (12%). Thirty-day mortality was lowest with early reperfusion (4.3% at <2 h vs. 9.2% at > or = 2 h, p=0.04) and was relatively independent of time to reperfusion after 2 h (9.0% at 2 to 4 h, 9.3% at 4 to 6 h, 9.5% at >6 h). Thirty-day-plus late cardiac mortality was also lowest with early reperfusion (9.1% at <2 h vs. 16.3% at > or = 2 h, p=0.02) and relatively independent at time to reperfusion after 2 h (16.4% at 2 to 4 h, 16.9% at 4 to 6 h, 15.6% at >6 h). Improvement in left ventricular ejection fraction was greatest in the early reperfusion group and relatively modest after 2 h (6.9% at <2 h vs. 3.1% at > or =2 h, p=0.007).


CONCLUSIONS
Time to reperfusion, up to 2 h, is important for survival and recovery of left ventricular function. After 2 h, recovery of left ventricular function is modest and survival is relatively independent of time to reperfusion. These data suggest that factors other than myocardial salvage may be responsible for survival benefit in patients treated with primary angioplasty after 2 h.
Brodie
B R
BR
Department of Medicine, The Moses H. Cone Memorial Hospital, University of North Carolina at Greensboro, USA.
Stuckey
T D
TD
Wall
T C
TC
Kissling
G
G
Hansen
C J
CJ
Muncy
D B
DB
Weintraub
R A
RA
Kelly
T A
TA
D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D001241:Aspirin / Q000627:therapeutic use; D006328:Cardiac Catheterization; D002423:Cause of Death; D017023:Coronary Angiography; D004359:Drug Therapy, Combination; D004562:Electrocardiography; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D005500:Follow-Up Studies; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000401:mortality* / Q000503:physiopathology / Q000628:therapy*; D015425:Myocardial Reperfusion / Q000379:methods*; D012189:Retrospective Studies; D013318:Stroke Volume; D015996:Survival Rate; D015912:Thrombolytic Therapy; D013997:Time Factors; D016277:Ventricular Function, Left / Q000502:physiology*
D005343:Fibrinolytic Agents; D006493:Heparin; D001241:Aspirin