Predicting mortality in patients with acute heart failure: Role of risk scores

Table 1 Main risk scores in acute heart failure

Risk score	Data source	Publication year	Sample size(derivation)	Sample size(validation)	Validation	Model development	Endpoint
In-hospital mortality
ADHERE[15]	Registry	2005	33046	32229	External	Classification trees	In-hospital mortality
AHFI[16]	Statewide databases	2005	33533	8384	External	Classification trees	In-hospital mortality and complications
OPTIMIZE-HF[19]	Registry	2008	37548	181830	Internal/external	Logistic regression model	In-hospital mortality
GWTG-HF[20]	Registry	2010	27850	11933	Internal/external	Logistic regression model	In-hospital mortality
EHMRG[21]	Population-based cohort	2012	7433	5158	Internal/external	Logistic regression model	7 d mortality
PROTECT[23]	Clinical trial	2012	2015	1435	Internal/external (clinical trial population)	Cox proportional hazards model	Composite endpoint of death, worsening heart failure or heart failure rehospitalization
Post-discharge mortality
EFFECT[24]	Community	2003	2624	1407	Internal/external	Logistic regression model	30 d mortality/1 yr mortality
OPTIME-CHF[25]	Clinical trial	2004	949	-	Internal	Cox proportional hazards model	60 d mortality
OPTIMIZE-HF[26]	Registry	2008	4402	949/433	Internal/external (clinical trial population)	Cox proportional hazards model	60-90 d post-discharge mortality
APACHE-HF[27]	Community (single centre)	2014	824	-	-	Cox proportional hazards model	90 d mortality
ELAN[28]	Pooled data of seven cohorts	2014	1301	325	External (clinical trial population)	Cox proportional hazards model	180 d mortality
ADHF/NT-proBNP[29]	Community	2013	453	371	External	Logistic regression model	1 yr mortality
ESCAPE[30]	Clinical trial	2010	433	471	Internal/external (clinical trial population)	Cox proportional hazards model	6 mo mortality

ADHERE: Acute decompensated heart failure national registry; AHFI: Acute heart failure index; OPTIMIZE-HF: Organized program to initiate lifesaving treatment in hospitalized patients with heart failure; GWTG-HF: Get with the guidelines-heart failure; EHMRG: Emergency heart failure mortality risk grade; PROTECT: Placebo-controlled randomized study of the selective A1 adenosine receptor antagonist rolofylline for patients hospitalized with acute decompensated heart failure and volume overload to assess treatment effect on congestion and renal function; EFFECT: Enhanced feedback for effective cardiac treatment; OPTIME-CHF: Outcomes of a prospective trial of intravenous milrinone for exacerbations of chronic heart failure; APACHE-HF: Acute physiology and chronic health evaluation in heart failure; ADHF/NT-proBNP: Acutely decompensated heart failure n-terminal pro-brain natriuretic peptide; ESCAPE: Evaluation study of congestive heart failure and pulmonary artery catheterization effectiveness; ELAN: European collaboration on acute decompensated heart failure.

Table 2 Variables used in the risk score models

Risk score	Variables
ADHERE[15]	BUN, creatinine, SBP
AHFI[16]	Gender, CAD, diabetes, lung disease, SBP, HR, respiratory rate, temperature, blood urea nitrogen, sodium, potassium, white blood cell count, acute myocardial infarction o myocardial ischemia at ECG, pulmonary congestion or pleural effusion on radiographic examination
OPTIMIZE-HF[19]	Creatinine, sodium, age, HR, liver disease, previous CVA/TIA, peripheral vascular disease, race, left ventricular systolic dysfunction, COPD, SBP, previous HF hospitalization
GWTG-HF[20]	Older age, low SBP, elevated heart rate, presence of COPD, and non-black race
EHMRG[21]	HR, creatinine, systolic blood pressure initial oxygen saturation, serum troponin
PROTECT[23]	BUN, respiratory rate, HR, albumin, cholesterol, diabetes, previous HF hospitalization
EFFECT[24]	Age, SBP, BUN, sodium concentration, cerebrovascular disease, dementia, COPD, hepatic cirrhosis, cancer, hemoglobin
OPTIME-CHF[25]	Age, BUN, SBP, sodium, NYHA class
OPTIMIZE–HF[26]	Age, weight, SBP, serum creatinine, history of liver disease, history of depression history of reactive airway disease
APACHE-HF[27]	Mean blood pressure, HR, serum sodium, serum potassium, creatinine, haematocrit, Glasgow coma scale, age
ELAN[28]	NT-proBNP at discharge, NT-proBNP reduction, age, peripheral oedema, SBP, sodium, serum urea, NYHA class
ADHF/NT-proBNP risk score[29]	COPD, SBP, eGFR, serum sodium, hemoglobin, NT-proBNP; left ventricular ejection fraction, tricuspid regurgitation
ESCAPE[30]	Age, BUN, six-minute walk test, sodium, CPR/mechanical ventilation, diuretic dose at discharge, no-blocker at discharge, BNP

BUN: Blood urea nitrogen; SBP: Systolic blood pressure; CAD: Coronary heart disease; HR: Heart rate; CVA: Cerebral vascular accident; COPD: Chronic obstructive pulmonary disease; CPR: Cardiopulmonary resuscitation; eGFR: Estimated glomerular filtration rate; NT-proBNP: N-terminal brain natriuretic peptide; ADHERE: Acute decompensated heart failure national registry; AHFI: Acute heart failure index; OPTIME-CHF: Outcomes of a prospective trial of intravenous milrinone for exacerbations of chronic heart failure; EHMRG: Emergency heart failure mortality risk grade; EFFECT: Enhanced feedback for effective cardiac treatment; OPTIMIZE-HF: Organized program to initiate lifesaving treatment in hospitalized patients with heart failure; PROTECT: Placebo-controlled randomized study of the selective A1 adenosine receptor antagonist rolofylline for patients hospitalized with acute decompensated heart failure and volume overload to assess treatment effect on congestion and renal function; GWTG-HF: Get with the guidelines-heart failure; APACHE-HF: Acute physiology and chronic health evaluation in heart failure; ADHF/NT-proBNP: Acutely decompensated heart failure n-terminal pro-brain natriuretic peptide; ESCAPE: Evaluation study of congestive heart failure and pulmonary artery catheterization effectiveness; ECG: Electrocardiogram; TIA: Transient ischemic attack; ELAN: European collaboration on acute decompensated heart failure.

Table 3 Performances of risk scores

Risk score	Calibration	C-statistic(derivation cohort)	C-statistic(validation cohort)	Low-risk group mortality (%)	High-risk group mortality (%)
In-hospital mortality
ADHERE[15]	NV	0.75	0.75	2.1	21.9
AHFI[16]	NV	NA	0.59	0.3	NA
OPTIMIZE-HF[19]	NV1	0.75	0.746	NA	NA
GWTG-HF[20]	Calibrated	0.75	0.75	0.4	9.7
EHMRG[21]	Calibrated	0.80	0.803	0.3	8.2
PROTECT[23]	Calibrated	0.67	0.67	4.81	28.72
Post-discharge mortality
EFFECT[24]	Calibrated	0.80 (30 d)	0.79 (30 d)	0.4 (30 d)	59 (30 d)
		0.77 (1 yr)	0.76 (1 yr)	7.8 (1 yr)	78.8 (1 yr)
OPTIME-CHF[25]	NV1	0.77	0.76	2	30
OPTIMIZE-HF[26]	NV	0.72	NA	NA	NA
APACHE-HF[27]	NV	0.78			202
ELAN[28]	NV	0.77	NA	3.6	51.1
ADHF/NT-proBNP risk score[29]	Calibrated	0.84	0.77	3.7	89.5
ESCAPE[30]	NV1	0.76	0.653	7	100

¹A graphic plot of the predicted vs observed probability of outcome was reported;

²Relative risk of death in the high-risk group vs the low-risk group;

³In the validation cohort, the model did not include brain natriuretic peptide and diuretic dose. NA: Not available; NV: Calibration was not verified by statistical tests; ADHERE: Acute decompensated heart failure national registry; AHFI: Acute heart failure index; OPTIMIZE-HF: Organized program to initiate lifesaving treatment in hospitalized patients with heart failure; GWTG-HF: Get with the guidelines-heart failure; OPTIME-CHF: Outcomes of a prospective trial of intravenous milrinone for exacerbations of chronic heart failure; EHMRG: Emergency heart failure mortality risk grade; EFFECT: Enhanced feedback for effective cardiac treatment; BNP: Brain natriuretic peptide; ADHF/NT-proBNP: Acutely decompensated heart failure n-terminal pro-brain natriuretic peptide; ESCAPE: Evaluation study of congestive heart failure and pulmonary artery catheterization effectiveness; PROTECT: Placebo-controlled randomized study of the selective A1 adenosine receptor antagonist rolofylline for patients hospitalized with acute decompensated heart failure and volume overload to assess treatment effect on congestion and renal function; ELAN: European collaboration on acute decompensated heart failure.