You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Outcome", "Participant", "Intervention"].

Please return the output as a JSON object of the format: {"Participant" : ["patients with COPD", ...], "Intervention" : ["Atenolol", ...], "Outcome" : ["blood pressure", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Early reperfusion and late clinical outcomes in patients presenting with acute myocardial infarction randomly assigned to primary percutaneous coronary intervention or streptokinase . BACKGROUND Primary percutaneous coronary intervention ( PCI ) has become an alternative to thrombolytic therapy as a reperfusion strategy for ST-elevation acute myocardial infarction ( AMI ) . METHODS The main goal of this study was to determine whether PCI and thrombolytic therapy achieve comparable reperfusion rates , as evidenced by ST-segment resolution . Secondary end points included infarct vessel patency rates before hospital discharge and short- and long-term outcomes . Patients with ischemic chest pain with duration < or =12 hours and no contraindication for thrombolytic therapy were included . RESULTS Between October 1993 and August 1995 , 58 patients were randomly assigned to streptokinase ( SK ) and 54 patients to primary PCI . Baseline clinical characteristics and infarct location were well balanced in both groups . Median age ( interquartile range ) was 68 ( 58 , 75 ) years , 29 % were women , and 78 % of the patients met at least one criterion for " not low risk " AMI ( anterior location , age > 70 years old , previous MI , systolic blood pressure < 100 mm Hg , and/or heart rate > 100 bpm ) . The median time from symptom onset to random assignment was 217 ( 139 , 335 ) minutes in the PCI group and 210 ( 145 , 334 ) minutes in the SK group . Median random assignment to balloon time was 82 ( 55 , 100 ) minutes , and median random assignment to needle time was 15 ( 10 , 26 ) minutes ( P < .0001 ) . TIMI grade 3 flow after primary PCI was obtained in 85 % of patients . The proportion of patients with ST-segment resolution > or =50 % at 120 minutes was 80 % in the PCI group and 50 % in the SK group ( P =.001 ) . The predischarge angiogram showed the presence of TIMI 3 flow in 96 % of patients who received PCI and 65 % of patients who received SK ( P < .001 ) . A composite of in-hospital death , reinfarction , severe heart failure , stroke , and major bleeding occurred in 15 % of patients who received PCI and 21 % of patients who received SK ( P =.4 ) . At 3 years , freedom from the composite end point of AMI , postdischarge revascularization , and death was 61 % in the PCI group and 40 % in the SK group ( P =.025 ) . CONCLUSIONS Our study shows that primary PCI , as compared with SK , is associated with more effective ST-segment resolution , higher patency rates in the infarct vessel at 7 days , and more favorable clinical outcomes at 3 years of follow-up .
{"Intervention": ["streptokinase ( SK )", "thrombolytic therapy", "SK", "PCI", "Primary percutaneous coronary intervention ( PCI )", "streptokinase", "primary PCI", "primary percutaneous coronary intervention"], "Outcome": ["reinfarction", "postdischarge revascularization", "blood pressure", "major bleeding", "composite end point of AMI", "TIMI grade 3 flow", "infarct vessel patency rates", "needle time", "ST-segment resolution", "stroke", "presence of TIMI 3 flow", "patency rates", "balloon time", "severe heart failure", "median time from symptom onset", "in-hospital death"], "Participant": ["patients presenting with acute myocardial infarction", "women", "ischemic chest pain", "68", "58", "54", "\u003e 70 years", "ST-elevation acute myocardial infarction ( AMI ) ."]}