Is preinfarction angina associated with better outcome after myocardial infarction?
BACKGROUND
In a clinical setting of acute myocardial infarction (MI), short-lasting and transient anginal pain, preceding the development of acute MI, is regarded as a symptom representing ischaemic preconditioning. Some experimental and clinical data suggested that preinfarction angina may favourably influence the course of acute MI.


OBJECTIVE
We sought to examine the hypothesis that preinfarction angina occurring within 24 hours prior to the onset of acute MI favourably influences the outcome.


METHODS
The study group consisted of 331 patients who were admitted to our hospital due to acute MI with ST segment elevation with a symptom duration <12 hours and received thrombolysis. Preinfarction angina within 24 hours prior to MI was present in 80 patients whereas the remaining 251 patients had no chest pain preceding acute MI. The course of the in-hospital phase of MI (mean 15 days) was analysed.


RESULTS
In patients with preinfarction angina the in-hospital complication rate was significantly lower than in patients without angina preceding acute MI (p<0.001). Patients without preinfarction angina more frequently developed heart failure (p<0.001) or died (p<0.01) in hospital. Patients with preinfarction angina had significantly less extensive MI and had reperfusion symptoms more frequently. Multivariate analysis showed that there were three factors which independently favourably influenced survival: preinfarction angina (p=0.01), age < or =65 years (p=0.04) and duration of chest pain during acute MI < or =3h (p=0.03). Of the analysed group, 73 patients died in hospital. The independent variables predicting death included prior MI (p=0.04), history of diabetes (p=0.02), acute left bundle branch block (p=0.01) and age >65 years (p=0.03). Non-fatal re-infarction complicated the in-hospital course of MI in 27 patients. The independent variables which predicted this complication included age >65 years (p=0.03) and hypercholesterolemia (p=0.04).


CONCLUSIONS
Patients with preinfarction angina, occurring within 24 hours of acute MI, have better in-hospital outcome and less extensive myocardial injury than patients without antecedent angina. These results may be attributed to the protective effects of ischaemic preconditioning.
Górecki
Aleksander
A
Department of Cardiology, Postgraduate Medical School, Grochowski Hospital, Warsaw, Poland.
Chamiec
Tomasz
T
Bednarz
Bronisław
B
Maciejewski
Paweł
P
Łukaszewicz
Rafał
R
Ceremuzyński
Leszek
L
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000787:Angina Pectoris / Q000150:complications* / Q000503:physiopathology*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D001145:Arrhythmias, Cardiac / Q000150:complications / Q000175:diagnosis; D001241:Aspirin / Q000627:therapeutic use; D004562:Electrocardiography; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology* / Q000503:physiopathology* / Q000534:rehabilitation; D012189:Retrospective Studies; D013300:Streptokinase / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D000894:Anti-Inflammatory Agents, Non-Steroidal; D005343:Fibrinolytic Agents; D013300:Streptokinase; D001241:Aspirin