Patient selection:
(1) NYHA functional classes I (2%), II (59%), III (39%)
(2) age 18 to 85 years with mean age 62.7 (+/- 9.7)
(3) ejection fraction < 45%, cardiothoracic ratio > 0.55 or pulmonary edema on chest X-ray
(4) Most patients were treated with ACE inhibitors and loop diuretics.
Risk factors:
(1) low standard deviation of all normal-to-normal RR intervals (SDNN), measured as described in Nolan (1998) and Task Force (1996), below median of 112 ms
(2) low serum sodium (below median of 140 mmol/L)
(3) increased serum creatinine (above median of 111 µmol/L)
|
Risk Factor |
Hazard Ratio |
95% CI |
p value |
|
SDDN 10% decrease |
1.06 |
1.01 – 1.12 |
0.012 |
|
sodium 2 mmol/L decrease |
1.22 |
1.08 – 1.38 |
< 0.001 |
|
creatinine 10 µmol/L increase |
1.14 |
1.09 – 1.19 |
0.001 |
The presence of one or more of these risk factors in a patient with heart failure indicates a patient at increased risk of progressive disease.
NOTES:
(1) I could not find a risk score showing a change in risk as the number of risk factors increased. Since the risk factors are independent I assume that the risk is additive.
(2) The number of NYHA class I is small while number of class III is significant.
(3) Transportability of score might require some slight modification of cut-off values. Sodium and creatinine tend to show good agreement between methods, although this would need to be checked.
