Kylhammar et al reported a risk stratification strategy for patients with pulmonary arterial hypertension (PAH). The authors are from multiple institutions in Sweden.
Patient selection: pulmonary arterial hypertension
Parameters:
(1) WHO functional class (from I to IV)
(2) 6 minute walking distance in meters (6MWD)
(3) NT-proBNP in ng/L
(4) RA area in square cm
(5) pericardial effusion
(6) right atrial pressure in mm Hg (RAP)
(7) cardiac index in liters per minute per square meter
(8) mixed venous blood oxygenation in percent (SvO2)
Points are assigned for low (1), intermediate (2) and high (3) risk.
|
Parameter
|
Finding
|
Points
|
|
WHO functional class
|
I or II
|
1 (low)
|
|
|
III
|
2 (intermediate)
|
|
|
IV
|
3 (high)
|
|
6MWD
|
> 440 meters
|
1
|
|
|
165-440
|
2
|
|
|
< 165 meters
|
3
|
|
NT-proBNP
|
< 300 ng/L
|
1
|
|
|
300-1400 ng/L
|
2
|
|
|
> 1400 ng/L
|
3
|
|
RA area
|
< 18 square cm
|
1
|
|
|
18-26
|
2
|
|
|
> 26
|
3
|
|
pericardial effusion
|
none
|
1
|
|
|
minimal
|
2
|
|
|
present
|
3
|
|
right atrial pressure
|
< 8 mm Hg
|
1
|
|
|
8-14
|
2
|
|
|
> 14
|
3
|
|
cardiac index
|
>= 2.5 L/min per sq m
|
1
|
|
|
2.0-2.4
|
2
|
|
|
< 2.0
|
3
|
|
SvO2
|
>65%
|
1
|
|
|
60-65%
|
2
|
|
|
<60%
|
3
|
total score =
= SUM(points for all 8 parameters)
average score =
= (total score) / 8
Interpretation:
• minimum average score: 1
• maximum average score: 3
• Final risk group corresponded to ROUND(average score,0).
• Patients assigned to the low risk category had a reduced mortality risk at follow-up.
