Streptokinase

Abstract

Streptokinase has been administered to many thousands of elderly patients with acute myocardial infarction. Results of large, randomised trials provide convincing evidence that intravenous streptokinase confers a distinct survival benefit in this population subgroup following myocardial infarction. The placebo-controlled ISIS-2 study demonstrated a 5-week absolute mortality reduction of 38 per 1000 patients aged 60 to 69 years administered streptokinase, compared with only 16 per 1000 for patients aged less than 60 years. Combining streptokinase with aspirin further reduces mortality, as shown by a 5-week absolute mortality reduction of 70 per 1000 patients aged 60 to 69 years administered this regimen in the ISIS-2 trial. While ideally patients should receive streptokinase as soon as possible after symptom onset, late benefit has been observed in patients presenting up to 12 hours after pain onset, as is often the case with the elderly. Indeed, in patients treated > 6 hours after infarct in the GUSTO trial, streptokinase produced lower mortality results than accelerated recombinant tissue plasminogen activator (rt-PA). However, in contrast to the similar effects of streptokinase and conventionally administered rt-PA on overall survival demonstrated in previous large trials, the GUSTO study showed a lower mortality rate for accelerated rt-PA than for streptokinase in the elderly and in the total patient population. The most frequent adverse effects associated with streptokinase therapy are haemorrhagic complications, with an incidence of 0.4% for major bleeding (requiring transfusion) and 3.6% for minor bleeding among the total population in the GISSI-1 and ISIS-2 trials. An excess of stroke, particularly haemorrhagic stroke, occurring with rt-PA in GUSTO and other major mortality trials affirms the use of streptokinase as a suitable option in the elderly who are at increased risk of this complication. Significantly reduced values of end-systolic volume and regional wall motion index have been observed in elderly patients following streptokinase therapy. Overall, streptokinase and rt-PA seem to cause similar improvements in left ventricular function in this age group. Patency of occluded coronary arteries appears to be achieved in a high percentage of elderly patients following streptokinase therapy, based on a small sample. Thus, in view of the extensive clinical experience that now exists, intravenous streptokinase represents an appropriate alternative in elderly patients with acute myocardial infarction, and may be considered a first-line therapy in selected individuals, such as those with multiple risk factors for stroke or who present later than 6 hours after infarct.(ABSTRACT TRUNCATED AT 400 WORDS)

Deletion of Ile1 Changes the Mechanism of Streptokinase: Evidence for the Molecular Sexuality Hypothesis

“…Like the blood coagulation pathway, the fibrinolytic pathway involves the sequential activation of trypsin-like serine proteases. The conversion of plasminogen to plasmin is the final step in the fibrinolytic pathway; plasmin is the protease responsible for the lysis of blood clots ( , ). This conversion involves proteolysis at the Arg561−Val562 bond of plasminogen; the new N-terminal amino group is believed to form a salt bridge with the carboxylate of Asp740 in a manner analogous to the activation of trypsinogen to trypsin () (chymotrypsinogen numbering, Table ).…”

Study of Adverse Events of Streptokinase Therapy in Patients with Acute ST Elevation Myocardial Infarction

“…The possible mechanism of hypotension is bradykinin mediated vasodilatation with peripheral pooling of the blood and this effect may be beneficial in patients of AMI presented acute heart failure. In some studies it was observed that the in hospital mortality was slightly lower in patients of AMI with acute heart failure receiving SK infusion [17].…”