Acute phase reaction, infarct size and in-hospital morbidity in myocardial infarction patients treated with streptokinase or recombinant tissue type plasminogen activator.

We examined the acute phase reaction in myocardial infarction after thrombolytic treatment by streptokinase or tissue plasminogen activator. The magnitude of the acute phase reaction as determined by measurements of serum C-reactive protein and amyloid-A protein did not correlate with infarct size (determined by serial measurements of creatine kinase-MB) in this patient population. On the other hand, the development of acute cardiac failure was more closely associated with the magnitude of the acute phase reaction than with infarct size. The peak serum values of C-reactive protein in patients with and without acute cardiac failure were 128 mg/l (95% confidence intervals 85-170) and 60 mg/l (30-89); P less than 0.01 and concentration time integrals 578 mg/l x days (368-787) and 205 mg/l x days (62-350); P less than 0.01. The corresponding creatine kinase-MB values were 310 U/l (191-429) and 207 U/l (125-289) not significant; and 319 U/l x days (201-437) and 204 U/l x days (124-286) not significant; respectively. Patients requiring medication for cardiac failure on discharge from hospital had higher C-reactive protein and serum amyloid A protein values than those who did not, although the difference did not quite reach statistical significance. The infarct sizes were similar whether the patients needed medication for cardiac failure at discharge or not. Subjectively felt morbidity due to myocardial infarction was linearly associated with serum C-reactive protein peak values (P less than 0.05) and concentration time integrals (P less than 0.05), but not with infarct size. We conclude that thrombolytic treatment of myocardial infarction may reduce hospital inpatient morbidity independently of the limitation of infarct size. This diminished morbidity seems to be associated with modest or low acute phase reaction.