This is an excellent question for which there is no easy answer. This corresponds to an overall reduction of 21 deaths per 1000 patients treated in this manner.
Time is of essence with the use of thrombolytic treatment.
Higher benefits are achieved when it is given within 6 hours of the onset of heart attack symptoms. Best results are observed within two to three hours but continues to be beneficial even if started within 12 hours. 35 per 1000 lives are saved when it is used within the first hour of symptoms. This drops to 16 lives saved per thousand if treatment is delayed for 7 to 12 hours. Thrombolytic therapy benefits the patient regardless of age, sex or presence of risk factors for coronary artery disease.