The 5-year Risk of A Cardiac Event When A Treadmill Stress Test Is Negative
Clinical Question
In an asymptomatic patient, what is the risk of developing a cardiac event
within five years of a negative treadmill stress test?
Clinical Bottom Line
- There is a low but measurable risk of a coronary event (7 %) within the
next 4 to 5 years following a normal (negative) treadmill stress test, and the
addition of thallium is not very useful in predicting a lack of subsequent
events.
The Evidence
| Negative TST* |
Event |
No Event |
Accuracy |
LR |
Event Rate (%) |
| Positive TTST** |
1 |
31 |
PPV = 3% |
0.43 |
3 |
| Negative TTST |
23 |
286 |
NPV = 93% |
1.06 |
7 |
|
24 |
317 |
Total 341 |
|
7 |
| Positive TST |
Event |
No Event |
Accuracy |
LR |
Event Rate (%) |
| Positive TTST |
11 |
12 |
PPV = 48% |
2.86 |
48 |
| Negative TTST |
5 |
38 |
NPV = 88% |
0.41 |
12 |
|
16 |
50 |
Total 66 |
|
24 |
* Treadmill Stress Test
** Thallium Treadmill Stress Test
Comments
- There was a well-defined, representative group of patients with comparable
health status.
- There was no referral bias.
- Objective and unbiased outcome criteria were used.
- Follow-up was 98% complete including 379 of 407 during subsequent biennial
visits.
- Addition of thallium scintigraphy in those with a negative TST was not
useful in predicting subsequent coronary events or no events (+ LR of 0.43, - LR
of 1.06). It is useful in predicting a higher risk for a subsequent event when
the TST is positive ( + LR of 2.86, - LR of 0.41).
APPRAISED BY: Richard I. Frankel, MD, MPH
DATE: February 7, 1997
REVIEWED BY: Irwin Schatz, MD
Fleg Jl. Prevalence and Prognostic Significance of Exercise-induced
Silent Myocardial Ischemia in Apparently Healthy Subjects. Am J Cardiology,
1992;69:14B-18B.
