[Troponin T, B type Natriuretic Peptide, and Isoenzim CK-MB] Those "Three" and AMI

Well, I just wanna share a bit of the background of my thesis. It's about how significant the correlation of this laboratory test with Acute Coronary Syndrome. Some of the researchs that inspired me were taken from the new England journal of medicine. It's about Cardiac Troponin and the other is about B-type natriuretic peptide. So that, I pointed my research with isoenzim CK-MB laboratory test. 

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Okay, this the first journal, about Cardiac Troponin T (well, I just write the review)

 

Troponin T Levels in Patients with Acute Coronary Syndromes, with or without Renal Dysfunction

Background

Among patients with suspected acute coronary syndromes, cardiac troponin T levels have prognostic value. However, there is concern that renal dysfunction may impair the prognostic value, because cardiac troponin T may be cleared by the kidney.

Methods

We analyzed the outcomes in 7033 patients enrolled in the Global Use of Strategies to Open Occluded Coronary Arteries IV trial who had complete base-line data on troponin T levels and creatinine clearance rates. The troponin T level was considered abnormal if it was 0.1 ng per milliliter or higher, and creatinine clearance was assessed in quartiles. The primary end point was a composite of death or myocardial infarction within 30 days.

Results

Death or myocardial infarction occurred in 581 patients. Among patients with a creatinine clearance above the 25th percentile value of 58.4 ml per minute, an abnormally elevated troponin T level was predictive of an increased risk of myocardial infarction or death (7 percent vs. 5 percent; adjusted odds ratio, 1.7; 95 percent confidence interval, 1.3 to 2.2; P<0.001). Among patients with a creatinine clearance in the lowest quartile, an elevated troponin T level was similarly predictive of increased risk (20 percent vs. 9 percent; adjusted odds ratio, 2.5; 95 percent confidence interval, 1.8 to 3.3; P<0.001). When the creatinine clearance rate was considered as a continuous variable and age, sex, ST-segment depression, heart failure, previous revascularization, diabetes mellitus, and other confounders had been accounted for, elevation of the troponin T level was independently predictive of risk across the entire spectrum of renal function.

Conclusions

Cardiac troponin T levels predict short-term prognosis in patients with acute coronary syndromes regardless of their level of creatinine clearance. 


source (click to see further)


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And then, this is the second journal.

The Prognostic Value of B-Type Natriuretic Peptide in Patients with Acute Coronary Syndromes

 

Background

Brain (B-type) natriuretic peptide is a neurohormone synthesized predominantly in ventricular myocardium. Although the circulating level of this neurohormone has been shown to provide independent prognostic information in patients with transmural myocardial infarction, few data are available for patients with acute coronary syndromes in the absence of ST-segment elevation.

Methods

We measured B-type natriuretic peptide in plasma specimens obtained a mean (±SD) of 40±20 hours after the onset of ischemic symptoms in 2525 patients from the Orbofiban in Patients with Unstable Coronary Syndromes–Thrombolysis in Myocardial Infarction 16 study.

Results

The base-line level of B-type natriuretic peptide was correlated with the risk of death, heart failure, and myocardial infarction at 30 days and 10 months. The unadjusted rate of death increased in a stepwise fashion among patients in increasing quartiles of base-line B-type natriuretic peptide levels (P<0.001). This association remained significant in subgroups of patients who had myocardial infarction with ST-segment elevation (P=0.02), patients who had myocardial infarction without ST-segment elevation (P<0.001), and patients who had unstable angina (P<0.001). After adjustment for independent predictors of the long-term risk of death, the odds ratios for death at 10 months in the second, third, and fourth quartiles of B-type natriuretic peptide were 3.8 (95 percent confidence interval, 1.1 to 13.3), 4.0 (95 percent confidence interval, 1.2 to 13.7), and 5.8 (95 percent confidence interval, 1.7 to 19.7). The level of B-type natriuretic peptide was also associated with the risk of new or recurrent myocardial infarction (P=0.01) and new or worsening heart failure (P<0.001) at 10 months.

Conclusions

A single measurement of B-type natriuretic peptide, obtained in the first few days after the onset of ischemic symptoms, provides predictive information for use in risk stratification across the spectrum of acute coronary syndromes. Cardiac neurohormonal activation may be a unifying feature among patients at high risk for death after acute coronary syndromes. 

source (click to see further)

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Then finally, if you wanna see my thesis about isoenzim CK-MB click this.

 Well, it would be nice if we can have a discussion, so that comment to this post if you interested.