The HEART score provides clinical recommendations for patients presenting to the emergency
department (ED) with chest pain. The initial retrospective validation study suggested
that intermediate-risk patients have a 11.6% risk of a major adverse cardiac event
(MACE) at 6 weeks and should be admitted to hospital for further investigation and
treatment. Although inpatient admission facilitates timely investigations and treatment,
this is a resource-intensive process. This study examines whether intermediate HEART
score patients can be safely managed on an outpatient basis through rapid access chest
pain clinics (RACPC).
METHODS AND RESULTS
This retrospective observational study included all chest pain patients referred to
RACPCs from the ED between January 2018 and April 2020 in Regina and Saskatoon, Saskatchewan.
HEART scores for the study were recorded as the HEART score given by the ED physician,
and if this was unavailable, study authors calculated the HEART score from available
clinical information. The primary outcome was MACE, a composite measure of death,
acute coronary syndrome (ACS), stroke, coronary angiography, and revascularization
at 6 weeks in intermediate-risk patients. Secondary outcomes included the type of
MACE, rate of MACE before RACPC and the most predictive component of the HEART score.
Out of 1989 ED referrals, 817 were for intermediate-risk patients. 9.3% (n=104) intermediate-risk
patients experienced a MACE at 6 weeks, with coronary angiography being the most common
MACE. In intermediate-risk patients, 1.10% (n=9) of MACEs occurred before RACPC follow-up.
With angiography excluded, 0.73% of intermediate-risk patients experienced a MACE
before their RACPC visit. The components of the HEART score most predictive of MACE
were troponin (OR 11.0, 95% CI: 3.7-32.3) and history (OR 5.3, 95% CI: 2.4-11.8).
Our results challenge existing recommendations that patients with intermediate-risk
HEART scores should be admitted. Discharging patients from the ED for outpatient follow-up
is associated with the risk of an undetected MACE. In intermediate-risk patients,
the risk of MACE before RACPC follow-up was below the 2% acceptable miss threshold
recommended by the American College of Emergency Physicians. Conventional literature
considers angiography as a MACE, despite it being a desired therapeutic outcome. Excluding
angiography further reduces the risk of MACE before RACPC follow-up in intermediate-risk
patients. These events could be further minimized through more restrictive RACPC referral
processes that allow only intermediate-risk patients to be referred, as numerous studies
emphasize safe discharge of low-risk patients. Nonetheless, further studies are needed
to validate the safety of this model and effect on downstream admissions and cost