Delay in presentation after myocardial infarction.

Thrombolytic therapy reduces mortality in acute myocardial infarction (AMI), giving maximal benefit with early treatment. In the UK delayed presentation after AMI may reduce the advantages of thrombolysis. To assess this, 103 patients presenting with AMI to two London Hospitals were interviewed to determine the length and cause of delay from onset of chest pain to arrival at hospital. Forty-nine per cent of patients took longer than 2 h to arrive at hospital, and 21% took longer than 4 h. Patients who contacted their general practitioner (GP) had a significantly prolonged time delay (160 mins; 65-730: median; range) compared to those who went directly to hospital by ambulance (82 mins; 15-395; P < 0.0005), or on their own (90 min; 15-855; P < 0.005). Patients calling their GP took a similar duration to decide to seek help [decision time (30 min versus 25 mins) P = NS], but significantly longer to reach hospital once the decision was made (110 min versus 56 min; P < 0.0001), than those proceeding directly to hospital. Believing the pain was cardiac in origin significantly shortened decision time (15 min versus 45 min; P < 0.05), as did knowledge of the existence of thrombolysis (15 min versus 50 min; P < 0.05) and lack of prior cardiac symptoms (18 min versus 42 min; P < 0.05). Only 14% were aware of thrombolysis. Rank correlation confirmed that decision and total delay time were age independent. Delays of this magnitude may compromise the efficiency of thrombolysis.(ABSTRACT TRUNCATED AT 250 WORDS)