Differences in inflammatory activity at the onset of acute myocardial infarction according to the clinical presentation of preinfarction angina

It is unknown whether the pathogenetic mechanisms underlying acute myocardi al infarction (AMI) differ according to the clinical presentation of preinf arction angina, so the present study measured plasma levels of C-reactive p rotein (CRP) in 280 patients with AMI in whom serum creatine kinase levels were normal on admission and increased subsequently. Patients were classifi ed into 3 groups according to the type of preinfarction angina: no angina ( n=95), stable angina (n=48), and unstable angina (n=137). Patients with uns table angina were subdivided according to the Braunwald classification: cla ss IB (n=39), class IIB (n=22), and class IIIB (n=76). There were no differ ences among the 5 groups in baseline characteristics. CRP on admission was significantly higher and the level of physical activity at symptom onset wa s significantly lower in the Braunwald class IIIB group than in the other g roups, but no differences were observed among the other groups. Patients wi th preinfarction Braunwald class IIIB unstable angina had higher CRP levels on admission and symptom onset at a lower level of physical activity. In s uch patients, the pathogenetic mechanisms may differ from those in other su bsets of patients with AMI and active inflammation may playa more important role in AMI onset.