The use of Troponin as a prognostic indicator in critically ill patients
Date First Published:
March 6, 2007
Last Updated:
March 16, 2007
Report by:
Dr Stephen Buchan, FY2 (Royal Bolton hospital)
Three-Part Question:
In [critically ill patients on the ICU] is [a raised Troponin level] an [indicator of increased mortality and increased length of hospital stay]
Clinical Scenario:
A 65 year old man was admitted to the ICU department with ARDS secondary to acute pancreatitis. He was found to have a raised Troponin on random blood testing. It was considered whether the raised troponin was a poor prognostic indicator for the patient.
Search Strategy:
Medline 1966-2007 using the PUBMED and medscape interface.
Search Details:
([troponin OR troponin] AND [critical illness OR critically ill])LIMIT to english
Outcome:
Altogether 47 papers were found on Pubmed and 21 on Medscape of these 3 were relevant to the three part question
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Elevated troponin and myocardial infarction in the intensive care unit: a prospective study Lim W, Qushmaq I, Cook DJ, Crowther MA, Heels-Ansdell D, Devereaux PJ; Troponin T Trials Group. Sep-05 Canada | All patients 115 admitted to St Joseph's Hospital from 12 july to 12 september 2004. 22 patients were excluded as they did not have both a Troponin measured and an ECG performed |
Prospective cohort | Higher morbidity in patients with MI | 37.5% versus 17.6% p= 0.05 | Systematic screening was not performed. Clinical judgement was used when deciding to do troponins and ECG. |
| Higher morbidity in patients with MI | 50% versus 22% p=0.01 | ||||
| Length of hospital stay | no increase in length of stay | ||||
| The role of cardiac troponin I as a prognosticator in critically ill medical patients: a prospective observational cohort study King DA, Codish S, Novack V, Barski L, Almog Y. Aug-05 Israel | 128 consecutive patients admitted to ICU in the Soroka University Centre Hospital | Prospective observational Cohort study | Patients with elevated troponin had higher | a) Apache II scores p = 0.001 b) duration of mechanical ventilation p< 0.001 c) mortality p <0.001 | only a one off Troponin measurement was used and not the rise and fall required to meet the diagnostic criteria |
| Troponin v Apachie score | no difference in predicition of mortality p=0.08 | ||||
| Elevated Cardiac Troponin Levels in Critically Ill Patients: Prevalence, Incidence, and Outcomes MD; Deborah J. Cook, MSc(Epid), MD; Lauren E. Griffith, MSc(Math); Mark A. Crowther, MSc, 19/05/2006 USA | 198 patients on the ICU at St Josephs between nov 2000 and january 2002. These patients were classified as having myocardial infarction (cardiac troponin I level ≥1.2 µg/L and ischemic electrocardiographic changes), elevated troponin level only (≥1.2 µg/L and no ischemic electrocardiographic changes), or normal troponin levels. Events were classified as prevalent if they occurred within 48 hours after admission and as incident if they occurred 48 hours or later after admission. | Prevelance of Raised Troponin | 42.10% | 817 patients in total but only 198 used due to strict inclusion criteria | |
| Prevelance of MI | 22.20% | ||||
| Incidence of raised troponin | 11.80% | ||||
| Incidence of MI | 5.10% | ||||
| Median length of stay | MI-10 days/Raised Trop 8 days/ normal trop 10 days (p=0.7) | ||||
| Mortality | MI 44.4%/Elevated troponin 44.4%/normal troponin 33.7% (p=0.33) |
Author Commentary:
2 out of the 3 papers reviewed showed statistically significant differences in length of hospital stay and mortality for patients with MI. While only 1 out of 3 showed any significant difference in patients with Troponin rise only.
Bottom Line:
Citically ill patients with a raised Troponin in association with myocardial infarction have worse prognosis. However the same can not be said for those patients with an Troponin rise on its own.
References:
- Lim W, Qushmaq I, Cook DJ, Crowther MA, Heels-Ansdell D, Devereaux PJ; Troponin T Trials Group.. Elevated troponin and myocardial infarction in the intensive care unit: a prospective study
- King DA, Codish S, Novack V, Barski L, Almog Y.. The role of cardiac troponin I as a prognosticator in critically ill medical patients: a prospective observational cohort study
- MD; Deborah J. Cook, MSc(Epid), MD; Lauren E. Griffith, MSc(Math); Mark A. Crowther, MSc,. Elevated Cardiac Troponin Levels in Critically Ill Patients: Prevalence, Incidence, and Outcomes