Circadian variations of onset of acute myocardial infarction and efficacy of thrombolytic therapy

• Published in: Journal of the American College of Cardiology 1996-03, Vol.27 (4), p.774-778
• Main Authors: Kono, Tatsuji, Morita, Hiroshi, Nishina, Takuya, Fujita, Masashi, Hirota, Yuzo, Kawamura, Keishiro, Fujiwara, Akira
• Format: Article
• Language: English
• Subjects: Aged; Biological and medical sciences; Blood. Blood coagulation. Reticuloendothelial system; Circadian Rhythm; Cohort Studies; Drug Resistance; Female; Humans; Male; Medical sciences; Middle Aged; Myocardial Infarction - drug therapy; Myocardial Infarction - physiopathology; Pharmacology. Drug treatments; Plasminogen Activators - therapeutic use; Retrospective Studies; Thrombolytic Therapy; Time Factors; Tissue Plasminogen Activator - therapeutic use; Urokinase-Type Plasminogen Activator - therapeutic use
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/0735-1097(95)00552-8

Objectives. The present study investigated wether the onset of acute myocardial infarction and resistance to thrombolysis have similar circadian variations. Background. Circadian variations of the onset of acute myocardial infarction and resistance to thrombolysis in the early morning have been reported. Some studies have also reported a secondary peak incidence in late evening; however, it is not known whether the resistance to thrombolysis has a similar circadian variation in these patients. Methods. Six hundred eight Japanese patients with an acute myocardial infarction were the subjects of the study. Two hundred forty-four of the 608 patients were treated with thrombolysis within 12 h of the onset of symptoms. One hundred thirteen patients received urokinase, and 131 patients received tissue-type plasminogen activator (t-PA) over 60 min. Patency of the infarct-related artery, the primary end point of the study, was evaluated at 60 min after the initiation of thrombolytic therapy, and Thrombolysis in Myocardial Infarction (TIMI) grade 0, 1 or 2 was defined as resistant to thrombolysis. Results. The onset of acute myocardial infarction and resistance to thrombolysis showed circadian variations with early morning and late evening peaks (p < 0.001 and p < 0.05, respectively). These circadian patterns showed similar distributions as evaluated with Spearman's method (r = 0.70, p < 0.05), although resistance to thrombolysis showed a phase difference of about 2 h earlier than the infarction incidence. The circadian variation of the resistance to thrombolysis was independent of the types of thrombolytic agents (urokinase or t-PA). Conclusions. These findings suggest that adjustment of treatment based on the time of the onset of symptoms may be warranted for the patients with acute myocardial infarction.