Outcome of low-risk patients discharged home after a normal cardiac troponin I

Advances in congestive heart failure biomarkers

Congestive heart failure (CHF) is the leading cause of morbidity and mortality in the elderly worldwide. Although many biomarkers associated with in heart failure, these are generally prognostic and identify patients with moderate and severe disease. Unfortunately, the role of biomarkers in decision making for early and advanced heart failure remains largely unexplored. Previous studies suggest the natriuretic peptides have the potential to improve the diagnosis of heart failure, but they still have significant limitations related to cut-off values. Although some promising cardiac biomarkers have emerged, comprehensive data from large cohort studies is lacking. The utility of multiple biomarkers that reflect various pathophysiologic pathways are increasingly being explored in heart failure risk stratification and to diagnose disease conditions promptly and accurately. MicroRNAs serve as mediators and/or regulators of renin-angiotensin-induced cardiac remodeling by directly targeting enzymes, receptors and signaling molecules. The role of miRNA in HF diagnosis is a promising area of research and further exploration may offer both diagnostic and prognostic applications and phenotype-specific targets. In this review, we provide insight into the classification of different biochemical and molecular markers associated with CHF, examine clinical usefulness in CHF and highlight the most clinically relevant.

High-Risk Chief Complaints I: Chest Pain-The Big Three (an Update)

Nontraumatic chest pain is a frequent concern of emergency department patients, with causes that range from benign to immediately life threatening. Identifying those patients who require immediate/urgent intervention remains challenging and is a high-risk area for emergency medicine physicians where incorrect or delayed diagnosis may lead to significant morbidity and mortality. This article focuses on the 3 most prevalent diagnoses associated with adverse outcomes in patients presenting with nontraumatic chest pain, acute coronary syndrome, thoracic aortic dissection, and pulmonary embolism. Important aspects of clinical evaluation, diagnostic testing, treatment, and disposition and other less common causes of lethal chest pain are also discussed.

Impact of clinical predictors and routine coronary artery disease testing on outcome of patients admitted to chest pain decision unit

BACKGROUND

Chest pain decision unit (CDU) evaluation of patients with acute chest pain (ACP) and nondiagnostic electrocardiogram (ECG) usually includes noninvasive testing for coronary artery disease (CAD).

HYPOTHESIS

CAD evaluation will not improve clinical outcome in low-risk ACP patients.

METHODS

We studied 459 adults admitted to CDU with ACP and no troponin release who underwent noninvasive CAD testing (stress testing in 396 and coronary computed tomographic angiography in 63). Multivariate logistic regression was used to determine predictors of adverse outcome over a 3-year follow-up period.

RESULTS

Initial noninvasive test was normal in 367 (80%) and abnormal (positive or indeterminate) in 92 (20%). A total of 42 (9%) patients underwent invasive coronary angiography, and 16 (3.5%) underwent revascularization. During follow-up, 33 patients had a total of 36 major clinical events: 12 revascularizations, 9 myocardial infarctions, and 15 deaths. Multivariate logistic regression analysis identified abnormal ECG (odds ratio [OR]: 2.7, P = 0.03), typical chest pain (OR: 3.8, P = 0.002), diabetes (OR: 4.1, P = 0.001), and known CAD (OR: 2.3, P = 0.03) as independent predictors for adverse outcome, but not noninvasive test result. Thus, in 187 patients with no high-risk features (41% of the cohort), the annualized event rate was 0.5%. In 272 patients with at least 1 high-risk feature, annualized event rates were 2.8% and 5.7% when noninvasive test was normal or abnormal, respectively (P = 0.04).

CONCLUSIONS

Clinical risk stratification allows identification of patients at low risk of adverse outcome over an intermediate period of follow-up. Noninvasive testing is not warranted in such patients.

Can We Exclude the Diagnosis of Non-ST Segment Myocardial Infarction on the Basis of a Single Troponin I and a Symptom Duration ≥8 Hours?

Background. The use of a single troponin measurement to exclude the diagnosis of non-ST segment myocardial infarction (NSTEMI) in patients that present with ischemic symptom duration ≥8 hours is sometimes used in the Emergency Department. Study Objective. To describe the characteristics of patients with initial nondiagnostic troponin values who develop a positive troponin while in the Emergency Department and to evaluate whether NSTEMI can be excluded using symptom duration ≥8 hours and initial troponin I. Methods. Retrospective chart review of patients evaluated for NSTEMI in the Emergency Department. Results. 4,510 patients had at least two troponin I values obtained during the two-year study period. 115 (2.5%) of these patients had an initially nondiagnostic (<0.6 ng/mL) and subsequent positive (≥0.6 ng/mL) troponin I result. Twenty-five (22%) of the 115 had duration of symptoms ≥8 hours. Of these 25 patients, 18 had an intermediate first troponin value (i.e., >0.06 ng/mL, but <0.6 ng/mL). Only two of the remaining seven patients had a final primary diagnosis of NSTEMI. Conclusion. The use of a negative initial troponin I together with a symptom onset of ≥8 hours defines a population with a very low incidence of a hospital diagnosis of NSTEMI.

High-risk chief complaints I: chest pain--the big three

Chest pain is one of the most frequently seen chief complaints in patients presenting to emergency departments, and is considered to be a "high-risk" chief complaint. The differential diagnosis for chest pain is broad, and potential causes range from the benign to the immediately life-threatening. Although many (if not most) emergency department patients with chest pain do not have an immediately life-threatening condition, correct diagnoses can be difficult to make, incorrect diagnoses may lead to catastrophic therapies, and failure to make a timely diagnosis may contribute to significant morbidity and mortality. Several atraumatic "high-risk" causes of chest pain are discussed in this article, including myocardial infarction and ischemia, thoracic aortic dissection, and pulmonary embolism. Also included are brief discussions of tension pneumothorax, esophageal perforation, and cardiac tamponade.

Decreased patient charges following implementation of point-of-care cardiac troponin monitoring in acute coronary syndrome patients in a community hospital cardiology unit

BACKGROUND

The need to rapidly evaluate patients presenting to emergency departments and cardiology services for ruling in and ruling out acute myocardial infarction (AMI) is widely recognized as a clinical challenge. We determined the impact of incorporating point-of-care (POC) cardiac troponin I (cTnI) testing into a cardiology service regarding assay turn around time (TAT), patient length of stay (LOS), financial matrixes and patient outcomes compared to central laboratory cTnI testing.

METHODS

Patients presenting with symptoms suggestive of acute coronary syndrome (ACS) were enrolled pre-POC (PreCS, n=271) and post-POC (PostCS, n=274). POC cTnI determinations were performed at the bedside on the Dade Behring Stratus CS by nursing staff. Routine cTnI determinations were performed in the central laboratory (Dade Behring Dimension) by laboratory staff. Data were collected and analyzed on each patient per hospital stay by review of electronic medical and financial records. In addition, risk stratification outcomes for all cause death were determined at 30 days and 1 y following baseline sampling based on the 99th percentile cutoff concentrations of <0.1 microg/l for both assays.

RESULTS

There was a decrease in time from blood draw to result to healthcare provider (PreCS mean 76 min; PostCS mean 19.5 min; p<0.001) as well as a decrease trend in charge per patient admission (4281 dollars savings) following implementation of POC testing. Total charges per patient admission decreased by 25% PostCS vs. PreCS (17,163 dollars vs. 12,882 dollars); a composite of lower charges for: boarding (-21%), other departments (-58%), pharmacy (-28%), labs (-22%), non-cardiac procedures (-28%), cardiac procedures (-14%). The mean LOS also decreased 8% (p=0.05) from PreCS (2.36 days) to PostCS (2.19 days). cTnI reagents charges to the laboratory were higher for the POC assay, 10.54 dollars, vs. the central lab assay, 3.83 dollars. One year survival was greater in the <0.1 microg/l patients (PreCS 96.2%, PostCS 97.2%) compared to the >0.1 microg/l patients (PreCS 77.7%, PostCS 75.5%); both p<0.001. Kaplan-Meier survival curves showed early separation by 30 days in each group.

CONCLUSIONS

Our study demonstrates the cost effectiveness and clinical effectiveness of implementation of POC whole blood, cTnI testing for assisting clinicians with diagnostic and risk assessment of ACS patients.

The diagnostic value of troponin T testing in the community setting

BACKGROUND

Many patients presenting with chest pain to their family physician are referred to the emergency room, in part, due to lack of accurate objective diagnostic tools. This study aimed to assess the diagnostic value of bedside troponin T kit testing in patients presenting with chest pain to their family physician.

DESIGN

Prospective, multi-center study.

METHODS

Consecutive subjects with chest pain were recruited from 44 community clinics in Jerusalem. Following clinical assessment by the family physician, qualitative troponin kit testing was performed. Patients with a negative clinical assessment and negative troponin kit were sent home and all others were referred to the emergency room. The final diagnosis at the time of hospital discharge was recorded and telephone follow up was performed after 60 days. Positive predictive value, negative predictive value, sensitivity and specificity of troponin kit for myocardial infarction diagnosis and of family physician for hospitalization, were assessed.

RESULTS

Of 392 patients enrolled, 349 (89%) were included in the final analysis. The prevalence of myocardial infarction was 1.7%. The positive and negative predictive values of the troponin kit for myocardial infarction diagnosis were 100% and 99.7%, respectively. The positive and negative predictive values of the family physician's assessment to predict hospitalization were 41.4% and 94.1%, respectively.

CONCLUSIONS

Troponin kit testing is an important tool to assist the family physician in the assessment of patients with chest pain in the community setting. Troponin kit testing may identify otherwise undiagnosed cases of myocardial infarctions, and reduce unnecessary referrals to the emergency room.