ERASE chest pain
In patients presenting to the ER with Chest pain, can resting myocardial perfusion imaging improve triage?
Acute resting MPI with Tc-99m sestamibi is associated with improved triage decision making in symptomatic ED patients.
Prior Studies had shown that resting perfusion imaging could assist triage in patients presenting with chest pain. Patients with diabetes are considered to have elevated risk of having CAD, and overall increased one year mortality of all comers presenting to the ER with chest pain. This study assessed the use of Tc 99m-labeled isotopes to assist in triage of ER patients.
1. Rest Tc99 perfusion imaging decreased the rate of hospital admission of patients presenting with chest pain who ultimately did not have acute coronary ischemia. 2. Mortality and MACE at 30 days were not changed in the study and control groups. 3. Funding was provided by both the Agency for Healthcare Research and Quality and Bristol-Myers Squb (makers of Tc-99 sestamibi isotope)
- Patients presenting to the ER during daytime hours with chest pain without diagnostic ECG
- Divided into 1) usual care strategy or 2) scan strategy
- Multicenter (7 hospitals in the USA), randomized, controlled trial
- 7955 consecutive patients screened from 1997 to 1999. 2908 met eligability criteria. 2475 consented to participate.
- SPECT images interpreted as Normal, abnormal , or equivocal (which was considered as mildly abnormal)
- All patients had follow up ECGs, serial cardiac enzyme measurements, echocardiography and stress testing. If patients were discharged from the ER, this was done at a follow up appointment 24 to 36 hours later.
- The final diagnosis was assigned by principal investigators who were blinded to randomization and initial scan result.
- The primary endpoint was appropriateness of initial ED triage decision.
- 30 years old or older
- Presenting with chest pain or acute shortness of breath
- Symptoms ongoing or resolved no longer than 3 hours prior to consent.
- History of Myocardial Infarction
- Mean age: 53 years.
- 1260 randomized to usual care
- 1215 randomized to perfusion imaging.
- ACS was the final diagnosis in 13% of patients.
One patient from each group was inappropriately sent home. Among patients whose final diagnosis was not ACI: In the sestamibi scan group the unnecessary admission rate was 42% In the usual care group, the unnecessary admission rate was 52%. Among patients whose final diagnosis was ACI: In the sestambi scangroup, the rate of appropriate hospital admission was 84%. In the usual care group, the rate of appropriate hospital admission was 85%.
- Hospital admission
- 47.5% in scan strategy
- 56.1% in usual care strategy
Among patients randomized to the scan strategy, imaging results were related to risk of adverse outcomes. Risk of any cardiac event at 30 days (acute MI, death, revascularization) Normal scan - 3.0% Abnormal scan - 20.5% Equivocal Scan- 6.1%
There was no change in the 30 day clinical outcomes of the two groups. Rates of MI (2%) and UA (12%) were lower than those seen in previous studies. The scan strategy did not result in faster discharge times from the ER.
Funding was provided by both the Agency for Healthcare Research and Quality and Bristol-Myers Squb (makers of Tc-99 sestamibi isotope)