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
CARDIAC TROPONIN and OUTCOME in ACUTE HEART FAILURE
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
105,388 84,872 ( 80.5% )
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.
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
HPT / cardiomyopathy / Rheumatic heart disease / chronic lung disease / pericardial disease
that some patients with both heart failure and ACS may have been included!!!!