title: Survival analysis within one year of first acute myocardial infarction: comparison between non-Q and Q wave myocardial infarction.
abstract: BACKGROUND
  Non-Q wave Myocardial Infarction (non-Q AMI) is related pathophysiologically to Q wave AMI, as each represents different stages of plaque rupture and thrombosis. Post-hospital re-infarction and recurrent angina are more frequent in non-Q AMI than in Q wave AMI, offsetting the higher early risk with Q wave AMI, with one-year survival rates similar in the two types of MI.
  
  
  OBJECTIVE
  1--Evaluation of early (< or = 28 days) and one-year total mortality from first non-Q AMI in comparison to QMI. 2--Analysis of recurrent acute ischaemic events (non-fatal reinfarction and unstable angina) in both types of MI in the same periods of time.
  
  
  METHODS
  A retrospective study of 1146 patients, mean age 65 +/- 13 years, 65% male, admitted at CCU with a first MI, from January 1988 to December 1997 (minimum follow-up period of one year, mean follow-up 42 +/- 37 months). We compared the baseline demographics and clinical characteristics (coronary risk factors, previous angina, MI evolution, recurrent cardiac events, 28 day mortality and one year mortality) of patients with non-Q AMI (NQ group = 239) and Q wave AMI (Q group = 907).
  
  
  RESULTS
  The NQ group patients were significantly older (mean age: 67 +/- 12.6 vs 65 +/- 12.5 years; p < 0.05), included fewer smokers (29% vs 43%; p < 0.001) and were more symptomatic before the index infarction (stable angina: 40% vs 30%; p < 0.05; unstable angina: 16% vs 6%; p < 0.001), when compared to the Q group patients. There were no significant differences in MI evolution, in Killip-Kimbal class > or = 2, recurrent angina and in-hospital mortality (Q-12% vs NQ-9%; ns), although there was a higher combined risk of arrhythmias and AV conduction disturbances in patients with QMI (Q-34% vs NQ-26%; p < 0.05). The combined risk of unstable angina and reinfarction at one year was significantly higher in group NQ (NQ-13% vs Q-8.1%; p < 0.05). The NQ group showed no significant difference in 28 day total mortality (NQ-14% vs Q-17%; ns) or at one year follow-up (NQ-24% vs Q-26%; ns) when compared to the Q group.
  
  
  CONCLUSIONS
  1--Despite a lower severity of non-Q AMI in the acute phase, 28 day and one year total mortality were similar in the two groups. 2--Patients with non-Q AMI showed a higher incidence of recurrent ischemic events at one year follow-up.
authors.affiliation: Departamento de Cardiologia Médico-Cirúrgica, Centro Hospitalar do Funchal.
authors.forename: G
authors.initials: G
authors.lastname: Caires
authors.forename: D
authors.initials: D
authors.lastname: Pereira
authors.forename: A D
authors.initials: AD
authors.lastname: Freitas
authors.forename: F
authors.initials: F
authors.lastname: Teixeira
authors.forename: R
authors.initials: R
authors.lastname: Leite
authors.forename: J J
authors.initials: JJ
authors.lastname: Araújo
authors.forename: A
authors.initials: A
authors.lastname: Cardoso
authors.forename: A C
authors.initials: AC
authors.lastname: Pereira
authors.forename: M E
authors.initials: ME
authors.lastname: Macedo
authors.forename: M
authors.initials: M
authors.lastname: Diniz
mesh_terms: D000368:Aged; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality* / Q000503:physiopathology*; D016019:Survival Analysis