Morning Report: 10/10/2013

Today’s Morning Report is presented by Dr. Freedman!

Troponin-emia 101                 

Background

• Compromised of three subunits:  T, I, and C
  • Both T and I subunits are highly-specific for cardiac tissue
• Since 1995, has emerged as the cardiac biomarker of choice
  • Cardiac Specificity
  • Predictable time course
    • Rises above 99^th percentile within 4-8 hours and remains elevated for days
• In 2009, the first high-sensitivity troponin assays were reported.
  • Improved sensitivity = impaired specificity

“The Third Universal Definition of Acute Myocardial Infarction”

Some Definitions

• Ischemia
• Infarction
• ACS

99th percentile + 1 of the following

• EKG change
• Nuclear imaging defect
• Angiographic “culprit”

AMI Type 1-5

• Atheromatous plaque rupture
• Non-ACS supply/demand mismatch
  • CAD +/-
• Other

Troponin-emia in High-lighted Non-ACS 

• CVA, ICH, SAH
  • +Troponins in ~18% of all CVA
  • Mechanism unclear
    • Catecholamine surge ?
    • Concommitant CAD and ACS?
  • Carries significantly increased mortality
  • Study in progress in UK; TRELAS
• PE
  • Mechanism
    • RV strain?
    • Hypoexmia?
  • 63% of those with enlarged RV end-diastolic diameter have +troponin vs 29% of those without
  • Across studies, increased short-term all-cause mortality, even among those without massive PE

Chronic Troponin-ers

• ESRD
  • 82% of those receiving dialysis have elevated Trop T
  • Mechanism unclear
    • Does not relate to GFR
    • Increased afterload/Diastolic dysfunction
    • Concomitant CAD?
  • Clinical significance
    • Increased all-cause and cardiac mortality
    • Most useful for patient trends
• CHF
  • For ADHF patients, those with + troponins (low-sensitivity)
    • Lower SBP
    • Lower EF
    • Higher inpatient mortality
• Potpourri
  • 80-85% of marathoners have detectable troponins post-race

Conclusions

• New era high-sensitivity assays –> specificity for ACS falls
• Why is it important for EP’s?  PCI vs Medical vs Supportive
• All-comers with + troponins

References

• Kerr G, Ray G, Wu O, Stott DJ, Langhorne P.  Elevated troponin after stroke: a systematic review. Cerebrovasc Dis 2009;28:220-226.
• Jiménez D, Uresandi F, Otero R, Lobo JL, Monreal M, Martí D, Zamora J, Muriel A, Aujesky D, Yusen RD.  Troponin-based risk stratification of patients with acute nonmassive pulmonary embolism: systematic review and metaanalysis. Chest 2009;136:974-982.
• Mingels A, Jacobs L, Michielsen E, Swaanenburg J, Wodzig W, van Dieijen-Visser M. Reference population and marathon runner sera assessed by highly sensitive cardiac troponin T and commercial cardiac troponin T and I assays. Clin Chem 2009;55:101-108.
• Roberts M, Hedley A, Ierino F. Understanding cardiac biomarkers in end-stage kidney disease: Frequently asked questions and the promise of clinical application. Nephrology (Carlton, Vic.) [serial online]. March 2011;16(3):251-260.
• Peacock WF 4th., De Marco T, Fonarow GC,  Diercks D, Wynne, J,Apple FS, Wu AH; ADHERE Investigators. Cardiac troponin and outcome in acute heart failure. N Engl J Med 2008;358:2117-2126

The following two tabs change content below.

• Bio
• Latest Posts

Jay Khadpe MD

Editor in Chief of "The Original Kings of County" Assistant Professor of Emergency Medicine Assistant Residency Director SUNY Downstate / Kings County Hospital

Latest posts by Jay Khadpe MD (see all)

• Morning Report: 7/30/2015 - July 30, 2015
• Morning Report: 7/28/2015 - July 28, 2015
• IN THE STRETCHER INSTEAD OF BESIDE IT - July 22, 2015
• Morning Report: 7/14/2015 - July 14, 2015
• Morning Report: 7/10/2015 - July 10, 2015