Critical Appraisal. DR Joshna Rajbaran. CARDIAC TROPONIN and OUTCOME in ACUTE HEART FAILURE. NEJM 358;20 MAY 15,2008. THE AIM:. To describe the association between elevated cardiac troponin levels and adverse events in hospitalized patients with ACUTE DECOMPENSATED HEART FAILURE. WHY??.
DR Joshna Rajbaran
NEJM 358;20 MAY 15,2008
Trop T & Trop I are regulatory proteins with a very high specificity for cardiac injury . They are released early ( 2-4 hrs) & can persist for up to 7 days.
Troponin testing is primarily used as a tool in diagnosing myocardial infarctions.
Elevated levels suggest myocardial or some form of cardiac damage.
Insignificant if used in the absence of S&S of cardiac disease!!
Hospitalization & documentation of the measurement of trop I or trop T at “INITIAL” evaluation
serum creatinine level>2.0mg/dl
hx coronary artery disease OR
hx myocardial infarction
Not as exclusion criteria!!!
age / blood urea nitrogen / SBP /
DBP / serum creatinine / serum sodium / HR /dyspnea at rest
Hospitalized Trop tested
Cr < 2mg/dl
4240 (6,2%) 63,684
Odds ratio :provides a more useful way of presenting diagnostic data & can be applied to individual patients in a way that specificity & sensitivity cannot . It is a number btw 0 to infinity IF > 1 indicates that the information increases the likelihood of the suspected diagnoses. IF <1 it decreases the likelihood of the suspected diagnoses!!
SPECIFICITY: the proportion of patients WITHOUT the disease who are correctly identified by the test.
SENSITIVITY: the proportion of patients WITH the disease who are correctly identified by the test.
IHF was not a useful discriminator of Troponin status, nor was it predictive of mortality.
Prognostic value / cost
Early assessment of risk/ triage & management
Add to existing risk-stratification data for predicting the short term risk of death among patients with acute decompensated heart failure... Blood urea>15.4mmol/l
SBP < 115mm Hg
More aggressive therapeutic approach justified
Identifying low risk patients/ planning Rx
SMALLER STUDIES-98 CONSECUTIVE PTS
National-ACS Trop & brain natriuretic peptide or N- terminal pro-brain peptide.
Current for Heart Failure Trop NOT mentioned & brain nitriuretic peptide only if dx uncertain!!!
STRENGTHS & LIMITATIONS WITH SUGGESTIONS OFFERED
I FOUND NO REASON TO QUESTION THE STATISTICAL APPROACH
SUGGESTIONS FOR FUTURE STUDIES
OTHER RELEVANT STUDIES DOCUMENTED
HOWEVER, in Sub- Saharan Africa the causes in Africans are largely ( > 90%) NON-ISCHAEMIC viz.:
HPT / cardiomyopathy / Rheumatic heart disease / chronic lung disease / pericardial disease
that some patients with both heart failure and ACS may have been included!!!!