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Posts Tagged ‘hs-cTn’


Preparing the United States for High-Sensitivity Cardiac Troponin Assays

Curator: Larry Bernstein, MD, FCAP

 

UPDATED on 12/12/2017

Evidence Mounts for Myocardial Injury After Noncardiac Surgery

Patrice Wendling

December 11, 2017

Based on an absolute rise of high-sensitivity cardiac troponin T (hs-cTnT) of >14 ng/L from presurgery to postsurgery levels, perioperative myocardial injury (PMI) occurred in one out of seven surgeries (16%) in the prospective BASEL-PMI study.

Despite being at increased CV risk, 82% of patients did not show any ischemic symptoms and only 6% had chest pain. Overall, only 29% of patients fulfilled any of the additional criteria required for spontaneous acute MI such as loss of viable myocardium on imaging or ECG findings suggestive of myocardial ischemia.

Senior author and long-time proponent of hs-cTnT, Dr Christian Mueller (University Hospital of Basel), said in an email, “The current evidence may justify different conclusions on which patients undergoing noncardiac operations should receive hs-cTnT screening. Likely Dr Puelacher’s is the more precise one.

“On the other hand, the criteria to receive screening in our study are such that not all physicians (and patients) would consider these patients ‘high-risk patients’ (eg, all patients above the age of 65 years [until 85 years]).”

Patients with PMI had more CV comorbidities at baseline and a higher rate of nonelective surgery than those without.

Patients with PMI had six times the 30-day mortality of those without PMI (9.8% vs 1.6%), with the excess mortality persisting up to 1 year (22.5% vs 9.3%; both P<0.001).

Of special note, 30-day and 1-year mortality was comparable in PMI patients not fulfilling any additional criteria required for spontaneous AMI vs those fulfilling at least one additional criteria (10.4% vs 8.7%, P=0.684; and 22.1% vs 29.1%, P=0.47).

Although the use of hs-cTnT testing was approved in the US in 2017, he’s aware of only three hospitals that do routine troponin testing in noncardiac surgery patients—two in Switzerland and one in Brazil.

“We have a very close cooperation with anesthesiology and also with the surgical department, and that’s a prerequisite for actually doing this; maybe we need to look outside of our own realm to actually find this cooperation,” he added.

For those wanting to screen, the researchers caution that preoperative troponin measurements are needed to reliably distinguish PMI from chronic hs-cTnT elevations. In BASEL-PMI, 51% of patients already had preoperative hs-cTnT levels at or above 14 ng/L, while 13.8% patients in VISION had their peak value before surgery.

SOURCE

https://www.medscape.com/viewarticle/889852?nlid=119520_3866&src=WNL_mdplsfeat_171212_mscpedit_card&uac=93761AJ&spon=2&impID=1506822&faf=1

Frederick K. Korley, MD, Allan S. Jaffe, MD
Journal of the American College of Cardiology
J Am Coll Cardiol. 2013;61(17):1753-1758.

It is only a matter of time before the use of high-sensitivity cardiac troponin assays (hs-cTn) becomes common throughout the United States. In preparation for this inevitability, this article raises a number of important issues regarding these assays that deserve consideration. These include:

the need for the adoption of a universal nomenclature;

the importance of defining uniform criteria for reference populations;

the challenge of discriminating between acute and nonacute causes of hs-cTn elevations, and between type 1 and type 2 acute myocardial infarction (AMI);

factors influencing the analytical precision of hs-cTn;

ascertaining the optimal duration of the rule-out period for AMI;

the need for further evaluation to determine the causes of a positive hs-cTn in non-AMI patients; and

the use of hs-cTn to risk-stratify patients with disease conditions other than AMI.

This review elaborates on these critical issues as a means of educating clinicians and researchers about them.

Highlights:

Need for a Universally Accepted Nomenclature

Defining Uniform Criteria for Reference Populations

Discriminating Between Acute and Nonacute Causes of hs-cTn Elevations

Distinguishing Between Type 1 and Type 2 AMI

Analytical Imprecision in Cardiac Troponin Assays

Ruling Out AMI

Investigating the Causes of Positive Troponin Values in Non-AMI Patients

Risk Stratifying Patients With Nonacute Coronary Syndrome Conditions

Conclusions

typical changes in CK-MB and cardiac troponin ...

typical changes in CK-MB and cardiac troponin in Acute Myocardial Infarction (Photo credit: Wikipedia)

Troponin activation. Troponin C (red) binds Ca...

Troponin activation. Troponin C (red) binds Ca2+, which stabilizes the activated state, where troponin I (yellow) is no longer bound to actin. Troponin T (blue) anchors the complex on tropomyosin. (Photo credit: Wikipedia)

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