title: Comparison of in-hospital outcomes following early or delayed angioplasty for acute myocardial infarction.
abstract: BACKGROUND
  Studies of primary angioplasty for treatment of acute myocardial infarction (AMI) have not appeared to demonstrate a reduction in efficacy as a function of time to treatment. We sought to compare the outcomes of patients treated in New York State with primary angioplasty within 6 hours of symptom onset to those treated between 6 and 23 hours after the onset of AMI.
  
  
  METHODS
  We used data from the 1995 Coronary Angioplasty Reporting System of the New York State Department of Health to compare the in-hospital outcomes of patients treated with early (within 6 hours) or delayed angioplasty (6 23 hours) for AMI.
  
  
  RESULTS
  Early angioplasty (within 6 hours after onset of chest pain) was attempted in 957 patients (71.3%), while 385 patients (28.7%) had a delayed procedure (6 23 hours after the onset of chest pain). Patients who underwent delayed angioplasty were older (mean age, 62.6 years versus 60.4 years in the early group; p < 0.01) and more often female (36% vs. 28% in the early treatment group; p < 0.001). Patients treated early more frequently demonstrated hemodynamic instability (13.6% versus 9.1% in the late treatment group; p = 0.02), malignant ventricular arrhythmia (8.5% versus 2.9% in the late treatment group; p < 0.001) and cardiogenic shock (6.6% versus 1.8% in the late treatment group; p < 0.001). Overall in-hospital mortality was 63/1,342 (4.7%) with no difference based on early or delayed angioplasty (5.2% versus 3.4%, respectively; p = NS). The composite of the major adverse cardiac events including in-hospital death, reinfarction and emergency bypass surgery did not differ significantly between the early and delayed groups (7.7% versus 5.5%, respectively; p = NS). In multivariable models, delayed angioplasty was not an independent predictor of either in-hospital mortality or major adverse cardiac events.
  
  
  CONCLUSIONS
  Delayed reperfusion does not influence in-hospital clinical outcomes following PTCA for acute myocardial infarction.
authors.affiliation: Hochman Division of Cardiovascular Interventions, Beth Israel Medical Center, New York, New York 10461, USA.
authors.forename: V S
authors.initials: VS
authors.lastname: Srinivas
authors.forename: Babak A
authors.initials: BA
authors.lastname: Vakili
authors.forename: David L
authors.initials: DL
authors.lastname: Brown
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015906:Angioplasty, Balloon, Coronary / Q000379:methods* / Q000401:mortality; D006328:Cardiac Catheterization; D016009:Chi-Square Distribution; D015331:Cohort Studies; D017023:Coronary Angiography; D005260:Female; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D011336:Probability; D011379:Prognosis; D012042:Registries; D018570:Risk Assessment; D012720:Severity of Illness Index; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome