Participants randomized to CT coronary angiography with scan planned as soon as the CT scanner is available following the initial values assessment (expected within 90 minutes). Participants with negative test results will be discharged unless other indications for admission per standard of care. Participants with positive test results will be admitted to the hospital for further management as dictated by the admitting team.

CT Coronary Angiography: CT coronary angiography was performed without and with contrast in participants randomized to receive imaging as well as traditional care. (For applicable purposes, the decision to perform contrast-enhanced imaging in the presence of a large amount of calcium should be made according to procedures at each individual site.) The imaging test was considered positive if the participant has a greater than 50% stenosis of the right coronary, left main, left anterior descending, or circumflex arteries or of their branches in contrast-enhanced CT coronary angiography. Results were communicated to the responsible Emergency Department (ED) and treating staff immediately upon interpretation; ED staff will determine appropriate course of management.

In the traditional-care arm (Group A), all management and disposition decisions will be made by the healthcare providers caring for the participant. Participants will receive disposition (admit to hospital, admit to cardiac diagnostic unit, or discharge to home), diagnostic testing (none, stress testing, or cardiac catheterization), and treatment according to the team caring for the participant.

Traditional Strategy: Participants randomized to traditional care will be assessed and discharged/treated according to routine standard-of-care procedures in the institution's emergency department.

This group contains only those subjects from Group B where the imaging test was completed and negative: the participant had a <= 50% stenosis of the right coronary, left main, left anterior descending, and circumflex arteries and of their branches in contrast-enhanced CT coronary angiography.

Difference in AMI rate. NULL: equal rates of AMI in both Groups.

equivalence margin = 0

Participants will receive initial cardiac troponin and creatinine tests. Upon return of normal laboratory values (including a calculated creatinine clearance), the participants will receive a CT coronary angiography an estimated 90 minutes or as soon as the CT scanner is available following the initial values assessment. Participants with negative test results will be discharged unless other indications for admission per standard of care and follow up will comprise telephone interviews 30 days and 1 year after triage/presentation. Participants with positive test results will be admitted to the hospital for further management as dictated by the admitting team.

CT Coronary Angiography: CT coronary angiography will be performed without and with contrast in participants randomized to receive imaging as well as traditional care. (For applicable purposes, the decision to perform contrast-enhanced imaging in the presence of a large amount of calcium should be made according to procedures at each individual site.) The imaging test will be considered positive if the participant has a greater than 50% stenosis of the right coronary, left main, left anterior descending, or circumflex arteries or of their branches in contrast-enhanced CT coronary angiography. Results will be communicated to the responsible ED and treating staff immediately upon interpretation; ED staff will determine appropriate course of management. Negative results will result in patient discharge.

Participants will receive initial cardiac troponin and creatinine tests. Upon return of normal laboratory values (including a calculated creatinine clearance), the participants will receive a CT coronary angiography an estimated 90 minutes or as soon as the CT scanner is available following the initial values assessment. Participants with negative test results will be discharged unless other indications for admission per standard of care and follow up will comprise telephone interviews 30 days and 1 year after triage/presentation. Participants with positive test results will be admitted to the hospital for further management as dictated by the admitting team.

CT Coronary Angiography: CT coronary angiography will be performed without and with contrast in participants randomized to receive imaging as well as traditional care. (For applicable purposes, the decision to perform contrast-enhanced imaging in the presence of a large amount of calcium should be made according to procedures at each individual site.) The imaging test will be considered positive if the participant has a greater than 50% stenosis of the right coronary, left main, left anterior descending, or circumflex arteries or of their branches in contrast-enhanced CT coronary angiography. Results will be communicated to the responsible ED and treating staff immediately upon interpretation; ED staff will determine appropriate course of management. Negative results will result in patient discharge.

Participants will receive initial cardiac troponin and creatinine tests. Upon return of normal laboratory values (including a calculated creatinine clearance), the participants will receive a CT coronary angiography an estimated 90 minutes or as soon as the CT scanner is available following the initial values assessment. Participants with negative test results will be discharged unless other indications for admission per standard of care and follow up will comprise telephone interviews 30 days and 1 year after triage/presentation. Participants with positive test results will be admitted to the hospital for further management as dictated by the admitting team.

CT Coronary Angiography: CT coronary angiography will be performed without and with contrast in participants randomized to receive imaging as well as traditional care. (For applicable purposes, the decision to perform contrast-enhanced imaging in the presence of a large amount of calcium should be made according to procedures at each individual site.) The imaging test will be considered positive if the participant has a greater than 50% stenosis of the right coronary, left main, left anterior descending, or circumflex arteries or of their branches in contrast-enhanced CT coronary angiography. Results will be communicated to the responsible ED and treating staff immediately upon interpretation; ED staff will determine appropriate course of management. Negative results will result in patient discharge.

Participants will receive initial cardiac troponin and creatinine tests. Upon return of normal laboratory values (including a calculated creatinine clearance), the participants will receive a CT coronary angiography an estimated 90 minutes or as soon as the CT scanner is available following the initial values assessment. Participants with negative test results will be discharged unless other indications for admission per standard of care and follow up will comprise telephone interviews 30 days and 1 year after triage/presentation. Participants with positive test results will be admitted to the hospital for further management as dictated by the admitting team.

CT Coronary Angiography: CT coronary angiography will be performed without and with contrast in participants randomized to receive imaging as well as traditional care. (For applicable purposes, the decision to perform contrast-enhanced imaging in the presence of a large amount of calcium should be made according to procedures at each individual site.) The imaging test will be considered positive if the participant has a greater than 50% stenosis of the right coronary, left main, left anterior descending, or circumflex arteries or of their branches in contrast-enhanced CT coronary angiography. Results will be communicated to the responsible ED and treating staff immediately upon interpretation; ED staff will determine appropriate course of management. Negative results will result in patient discharge.

Participants will receive initial cardiac troponin and creatinine tests. Upon return of normal laboratory values (including a calculated creatinine clearance), the participants will receive a CT coronary angiography an estimated 90 minutes or as soon as the CT scanner is available following the initial values assessment. Participants with negative test results will be discharged unless other indications for admission per standard of care and follow up will comprise telephone interviews 30 days and 1 year after triage/presentation. Participants with positive test results will be admitted to the hospital for further management as dictated by the admitting team.

CT Coronary Angiography: CT coronary angiography will be performed without and with contrast in participants randomized to receive imaging as well as traditional care. (For applicable purposes, the decision to perform contrast-enhanced imaging in the presence of a large amount of calcium should be made according to procedures at each individual site.) The imaging test will be considered positive if the participant has a greater than 50% stenosis of the right coronary, left main, left anterior descending, or circumflex arteries or of their branches in contrast-enhanced CT coronary angiography. Results will be communicated to the responsible ED and treating staff immediately upon interpretation; ED staff will determine appropriate course of management. Negative results will result in patient discharge.