Pruvost et al developed a score for estimating the probability of coronary artery disease based on clinical and exercise test findings. This can help identify those patients who may benefit from more extensive evaluation. The authors are from Centre Hospitalier et Universitaire de Lille in France.
Exercise testing: standard Bruce protocol
Population: adult males
Parameters:
(1) age
(2) angina by history
(3) angina during exercise testing
(4) exercise duration in minutes
(5) maximal heart rate as percent of maximal age predicted heart rate (as a number from 0 to 100)
|
Parameter |
Finding |
Points |
|
angina by history |
no |
0 |
|
|
yes |
1 |
|
angina during exercise testing |
no |
0 |
|
|
yes |
1 |
maximal heart rate as percent of maximal age predicted heart rate =
= (maximal heart rate achieved) / (maximal age predicted heart rate) * 100%
score =
= (0.045 * (age in years)) + (0.794 * (points for history of angina)) + (0.863 * (points for anginal symptoms during exercise testing)) - (0.094 * (exercise duration)) - (0.023 * (percent of maximal age predicted heart rate)) - 0.251
Interpretation:
• minimum score: around -3
• maximum score: around +3
• The higher the score the greater the probability of coronary artery disease.
• A score of 0 is associated with a 50% chance of coronary artery disease.
• The probability of coronary artery disease is looked up on a curve shown in Figure 1 on page 1290.
|
Score |
Probability of Coronary Artery Disease |
|
-2.5 |
0.00 |
|
-2 |
0.05 |
|
-1.88 |
0.10 |
|
-1.5 |
0.18 |
|
-1 |
0.20 |
|
-0.75 |
0.25 |
|
-0.5 |
0.27 |
|
-0.18 |
0.32 |
|
0 |
0.50 |
|
0.18 |
0.83 |
|
0.5 |
0.85 |
|
1 |
0.91 |
|
1.5 |
0.93 |
|
2 |
0.97 |
|
2.18 |
1.00 |
from Figure 1, page 1290
When the data is analyzed in JMP, the following regions are seen:
|
Score |
Probability of CAD |
|
< -2.5 |
0% |
|
-2.5 to - 0.18 |
(-0.01287 * ((score)^2)) + (0.10257 * (score)) + 0.3322 |
|
-0.18 to +0.18 |
(2.3148148 * ((score)^2)) + (1.416667 * (score)) + 0.5 |
|
+0.18 to +2.18 |
(0.0813749 * (score)) + 0.81518 |
|
> +2.18 |
100% |
Performance:
• Sensitivity 68%, specificity 83%, diagnostic accuracy 75%.
Specialty: Cardiology, Sports Medicine & Rehabilitation
ICD-10: ,
