high sensitivity troponin: friend or foe?

HIGH SENSITIVITY TROPONIN IN THE EMERGENCY DEPARTMENT:

FRIEND OR FOE?Rick Body

DISCLAIMERWhat I say is not necessarily my personal opinion.

COI: Expert adviser to NICE, active researcher in this area (including industry supported work)Image by RedHotHeat via Wikimedia Commons

HIGH SENSITIVITY TROPONIN READS HIGHERSo you get more positives

10ng/L

Standard troponin

HS-troponin

35ng/L14ng/L

Chest pain

Collapse

SOB

"Unwell"

0 17.5 35 52.5 70

34.4

68.4

36.5

20.4

12.2

19.8

11.1

10.5

Before hs-Tn After hs-Tn

0

20

40

60

80

All Age >75

74

32 3018

Before hs-Tn After hs-Tn

Proportion of positive results before & after introducing hs-cTnT

ANSWER: 50%

If your patient with suspected ACS has a positive troponin, what is the overall

probability that they have AMI?

Image by anieto2k on Flickr..comBody et al, JACC 2011; 58: 1332-9

WHY DO WE NEED A HIGH SENSITIVITY ASSAY?

SO WE CAN SEE LEVELS IN NORMAL PEOPLE

Because that's so helpful in practice, right?

2. BECAUSE THE RESULTS ARE MORE

PRECISEWith a 25% CV instead of 10%:

An extra 0.3% of patients will have a false positive result after 2 tests

!

"We believe that the clinical implications of this false positive frequency are

insignificant"

Apple et al, Clin Chem 2005; 51:2198-2200

WHAT’S THE EVIDENCE OF BENEFIT?

I REST MY CASE, M'LUDMay justice be done