EHMRG is a weighted sum of variables measured at emergency department (ED) presentation. The model includes five continuous variables (age, systolic blood pressure, heart rate, peripheral oxygen saturation and serum creatinine) and categorical points for potassium, troponin, active cancer, outpatient metolazone use and arrival by ambulance.

Continuous component:

EHMRG (continuous) = 2 × age (years) − SBPcapped (mmHg) + heart ratecapped (beats/min) − 2 × oxygen saturationcapped (%) + 20 × creatinine (mg/dL) + 12.

Where:

SBPcapped is triage systolic blood pressure capped at 160 mmHg.
Heart ratecapped is triage heart rate truncated to the 80–120 beats/min range.
Oxygen saturationcapped is peripheral oxygen saturation capped at 92%.
Creatinine (mg/dL) is calculated from creatinine in µmol/L ÷ 88.4.

Categorical points added:

Serum potassium <, 4.0 mmol/L: +5 points, 4.0–4.5 mmol/L: 0 points, ≥4.6 mmol/L: +30 points.
Troponin above the local upper limit of normal: +60 points.
Active cancer: +45 points.
Metolazone use at home: +60 points.
Transported to the ED by ambulance (EMS): +60 points.

Total EHMRG score = continuous component + categorical points, higher scores indicate higher 7-day mortality risk.

Risk group	EHMRG score range	Description
1	≤ -49.1	Very low risk
2	-49.0 to -15.9	Very low risk
3	-15.8 to 17.9	Low–intermediate risk
4	18.0 to 56.5	Intermediate risk
5a	56.6 to 89.3	High risk
5b	≥ 89.4	Very high risk

Emergency Heart Failure Mortality Risk Grade (EHMRG) 7-day mortality risk stratification in the ED