ST-segment recovery and outcome after primary percutaneous coronary intervention for ST-elevation myocardial infarction: insights from the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) trial.
BACKGROUND
Primary percutaneous coronary angioplasty is an effective and widely adopted treatment for acute myocardial infarction. A simple method of determining prognosis after primary percutaneous coronary intervention (PCI) would facilitate appropriate care and expedite hospital discharge. Thus, we determined the prognostic importance of various measures of ST-segment-elevation recovery after primary PCI in a large, contemporary cohort of patients with ST-elevation myocardial infarction.


RESULTS
We analyzed ECG data describing the magnitude and extent of ST-segment elevation and deviation before and early after (ie, 30 minutes) primary PCI in the study cohort of 4866 subjects with electrocardiographically high-risk ST-elevation myocardial infarction enrolled in the Assessment of PEXelizumab in Acute Myocardial Infarction (APEX-AMI) trial. Associations among 6 methods for calculating ST-segment recovery, biomarker estimates of infarct size (ie, peak creatine kinase, creatine kinase-MB, and troponin I and T), and prespecified clinical outcomes (ie, rates of 90-day death and 90-day death, heart failure, or shock) were examined. All ST-segment-recovery methods provided strong prognostic information regarding clinical outcomes. A simple ST-segment-recovery method of residual ST-segment elevation measurement in the most affected lead on the post-PCI ECG performed as well as complex methods that required comparison of pre- and post-PCI ECGs or calculation of summed ST-segment deviation in multiple leads (ie, worst-lead residual ST elevation: adjusted hazard ratio for 90-day death rate [reference <1 mm]: 1 to <2 mm, 1.23 [95% CI 0.74 to 2.03]; > or =2 mm, 2.22 [95% CI 1.35 to 3.65], corrected c-index=0.832; 90-day death/congestive heart failure/shock [reference <1 mm]: 1 to <2 mm, 1.55 [95% CI 1.06 to 2.26]; > or =2 mm, 2.33 [95% CI 1.59 to 3.41], corrected c-index=0.802). Biomarker estimates of infarct size declined in association with enhanced ST-segment recovery.


CONCLUSIONS
An ECG performed early after primary PCI is a simple, widely available, inexpensive, and powerful prognostic tool applicable to patients with ST-elevation myocardial infarction.
Buller
Christopher E
CE
Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
Fu
Yuling
Y
Mahaffey
Kenneth W
KW
Todaro
Thomas G
TG
Adams
Peter
P
Westerhout
Cynthia M
CM
White
Harvey D
HD
van 't Hof
Arnoud W J
AW
Van de Werf
Frans J
FJ
Wagner
Galen S
GS
Granger
Christopher B
CB
Armstrong
Paul W
PW
D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000401:mortality*; D000911:Antibodies, Monoclonal / Q000008:administration & dosage*; D061067:Antibodies, Monoclonal, Humanized; D015331:Cohort Studies; D003131:Combined Modality Therapy; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000401:mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000175:diagnosis / Q000401:mortality / Q000628:therapy; D011237:Predictive Value of Tests; D011379:Prognosis; D020127:Recovery of Function; D012770:Shock, Cardiogenic / Q000401:mortality; D057127:Single-Chain Antibodies; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D057127:Single-Chain Antibodies; C402724:pexelizumab