The value of bedside cardiac multibiomarker assay in rapid and accurate diagnosis of acute coronary syndromes

Desempenho Diagnóstico da Angiotomografia Computadorizada e da Avaliação Seriada de Troponina Cardíaca Sensível em Pacientes com Dor Torácica e Risco Intermediário para Eventos Cardiovasculares

Fundamento

A angiotomografia coronária (ATC) tem sido usada para avaliação de dor torácica principalmente em pacientes de baixo risco, e poucos dados existem com pacientes em risco intermediário.

Objetivo

Avaliar o desempenho de medidas seriadas de troponinas sensíveis e de ATC em pacientes de risco intermediário.

Métodos

Um total de 100 pacientes com dor torácica, TIMI score 3 ou 4 e troponina negativa foram prospectivamente incluídos. Todos os pacientes foram submetidos à ATC, e aqueles com obstruções ≥ 50% foram encaminhados à cineangiocoronariografia. Pacientes com lesões < 50% recebiam alta hospitalar, receberam alta e foram contatados 30 dias depois por telefonema para avaliação dos desfechos clínicos. Os desfechos foram hospitalização, morte, e infarto agudo do miocárdio em 30 dias. A comparação entre os métodos foi realizada pelo teste de concordância kappa. O desempenho das medidas de troponina e da ATC na detecção de lesões coronárias significativas e desfechos clínicos foi calculado. Os resultados foram considerados estatisticamente significativos quando p <0,05.

Resultados

Estenose coronária ≥ 50% na ATC foi encontrada em 38% dos pacientes e lesões coronárias significativas na angiografia coronária foram encontradas em 31 pacientes. Dois eventos clínicos foram observados. A análise de concordância Kappa mostrou baixa concordância entre as medidas de troponina e ATC na detecção de lesões coronárias significativas (kappa = 0,022, p = 0,78). O desempenho da ATC para detectar lesões coronárias significativas na angiografia coronária ou para prever eventos clínicos em 30 dias foi melhor que as medidas de troponina sensível (acurácia de 91% versus 60%).

Conclusão

ATC teve melhor desempenho que as medidas seriadas de troponina na detecção de doença coronariana significativa em pacientes com dor torácica e risco intermediário para eventos cardiovasculares.

Implementation of a rapid chest pain protocol in the emergency department: A quality improvement project

PURPOSE

The purpose of this quality improvement (QI) project is to compare the effectiveness of a rapid 90-min chest pain screening and evaluation protocol to a 120-min screening and evaluation protocol in determining patient readiness for hospital admission or discharge home.

DATA SOURCES

The existing chest pain protocol utilized in the emergency department (ED) was revised based on a review of current research changing initial screening and reevaluation times from 120 to 90 min. A prospective comparative study of patients presenting to the ED with chest pain was performed comparing the existing chest pain protocol of 120 min (standard care) with a rapid screening evaluation protocol of 90 min. A total of 128 patients presenting to an ED in Texas with chest pain comprised the sample for this study.

CONCLUSIONS

There was a significant difference in the number of minutes between the groups for readiness for disposition. The average time from chest pain evaluation to readiness for disposition home, observation, or admission decreased from an average of 191 min in the standard care group to an average of 118 min in the rapid screening group.

IMPLICATIONS FOR PRACTICE

Use of the rapid screening and evaluation protocol decreased the time to disposition by an average of 73 min, which enhanced ED flow without influencing disposition and patient safety.

Use of a 90-minute protocol to evaluate patients presenting to the emergency department with chest pain: a case study

Frustration with emergency department wait times may contribute to patient delays in seeking care for subsequent episodes of chest pain and lower patient satisfaction ratings. In response to patient feedback and the dissemination of new knowledge, the existing emergency chest pain protocol was updated to include point-of-care laboratory testing and evaluation at baseline and 90 minutes. A case study was utilized to illustrate implementation of this protocol in the management of a patient presenting to the emergency department with chest pain.

Implementation of a chest pain management service improves patient care and reduces length of stay

OBJECTIVE

Chest pain is one of the most common complaints in patients presenting to an emergency department. Delays in management due to a lack of readily available objective tests to risk stratify patients with possible acute coronary syndromes can lead to an unnecessarily lengthy admission placing pressure on hospital beds or inappropriate discharge. The need for a co-ordinated system of clinical management based on enhanced communication between departments, timely and appropriate triage, clinical investigation, diagnosis, and treatment was identified.

METHODS

An evidence-based Chest Pain Management Service and clinical pathway were developed and implemented, including the introduction of after-hours exercise stress testing.

RESULTS

Between November 2005 and March 2013, 5662 patients were managed according to a Chest Pain Management pathway resulting in a reduction of 5181 admission nights by more timely identification of patients at low risk who could then be discharged. In addition, 1360 days were avoided in high-risk patients who received earlier diagnosis and treatment.

CONCLUSIONS

The creation of a Chest Pain Management pathway and the extended exercise stress testing service resulted in earlier discharge for low-risk patients; and timely treatment for patients with positive and equivocal exercise stress test results. This service demonstrated a significant saving in overnight admissions.

Hsp 70, hsCRP and oxidative stress in patients with acute coronary syndromes

Acute coronary syndromes (ACS) like unstable angina (UA) and acute myocardial infarction (AMI) can lead to the morbidity and mortality. The diagnosis and management of patients with ACS in the earliest times after symptom onset are considerably important in the emergency service. Study aimed to investigate the serum levels of heat shock protein 70 (Hsp 70), high sensitivity C-reactive protein (hsCRP), total creatine kinase (CK) activity, creatine kinase MB (CK-MB), cardiac troponin I (cTnI), leukocyte count (WBCs) and markers of oxidative stress in the first hours of ACS and to view their diagnostic values. 70 patients with ACS after admission and 20 sex-matched healthy controls were included in this study. Serum Hsp 70, hsCRP, CK, CK-MB, cTnI, protein carbonyls, malondialdehyde as well as whole blood WBCs were measured. The level of hsCRP was statistically higher in patients with AMI and UA than that of control group (p<0.001). WBCs and oxidized protein levels were higher in AMI than in UA and control groups. cTnI was related to CK-MB in AMI and UA groups (r=0.731, r=0.806, p<0.001, respectively) and also related with hsCRP in UA group (r=0.824, p<0.001). The mean Hsp 70 level was higher by 32.2% in AMI and 12.7% in UA patients compared to control subjects. hsCRP may have a role in the inflammatory response after ACS. In addition to cTnI and CK-MB, WBCs and hsCRP may be useful as a marker for the identification of ACS patients with chest pain in early diagnosing.

Evaluation of first-draw whole blood, point-of-care cardiac markers in the context of the universal definition of myocardial infarction: a comparison of a multimarker panel to troponin alone and to testing in the central laboratory

CONTEXT

Previous studies evaluating point-of-care testing (POCT) for cardiac biomarkers did not use current recommendations for troponin cutoff values or recognize the recent universal definition of acute myocardial infarction. Traditionally, achieving optimal sensitivity for the detection of myocardial injury on initial presentation required combining cardiac troponin and/or creatine kinase isoenzyme MB with an early marker, usually myoglobin. In recent years, the performance of central laboratory combining cardiac troponin assays has improved significantly, potentially obviating the need for a multimarker panel to achieve optimum sensitivity.

OBJECTIVE

To compare 2 commonly used POCT strategies to a fourth generation, central laboratory cardiac troponin T assay on first-draw specimens from patients being evaluated for acute myocardial infarction in the emergency department. The 2 strategies included a traditional POCT multimarker panel and a newer POCT method using cardiac troponin I alone.

DESIGN

Blood specimens from 204 patients presenting to the emergency department with signs and/or symptoms of myocardial ischemia were measured on the 2 POCT systems and by a central laboratory method. The diagnosis for each patient was determined by retrospective chart review.

RESULTS

The cardiac troponin T assasy alone was more sensitive for acute myocardial infarction than the multimarker POCT panel with equal or better specificity. When compared with a POCT troponin I, the cardiac troponin T was also more sensitive, but this difference was not significant. The POCT troponin I alone also had the same sensitivity as the multimarker panel.

CONCLUSIONS

Testing for combining cardiac troponin alone using newer, commercially available, central laboratory or POCT assays performed with equal or greater sensitivity to acute myocardial infarction as the older, traditional, multimarker panel. In the near future, high-sensitivity, central laboratory troponins will be available for routine clinical use. As a result, the quality gap between central laboratories and older POCT methods will continue to widen, unless the performance of the POCT methods is improved.

Future developments in chest pain diagnosis and management

Much of the focus of research on patients with chest pain is directed at technological advances in the diagnosis and management of acute coronary syndrome (ACS), pulmonary embolism (PE), and acute aortic dissection (AAD), despite there being no significant difference at 4 years as regards mortality, ongoing chest pain, and quality of life between patients presenting to the emergency department with noncardiac chest pain and those with cardiac chest pain. This article examines future developments in the diagnosis and management of patients with suspected ACS, PE, AAD, gastrointestinal disease, and musculoskeletal chest pain.

Current Trends in Diagnostic Biomarkers of Acute Coronary Syndrome

The diagnosis and management of patients with acute coronary syndrome (ACS) have evolved dramatically over the past decade. Biomarkers play an important role in the diagnosis of ACS, especially in unstable angina and non-ST-segment elevation myocardial infarction. Among these, cardiac troponin and creatine kinase appear to be the most sensitive and specific markers of myocardial injury. Recent studies have revealed several novel biomarkers. Elevated levels of C-reactive protein and interleukin-6 are strong independent markers of increased mortality among patients with ACS. However, the ideal biomarkers that offer early detection, risk stratification, selection of therapy, monitoring disease progression, and treatment efficacy remain to be elucidated. This review assesses limitations and contemporary needs for biomarkers in the context of diagnosis of ACS. It also discusses the newly developing technologies for novel biomarkers or novel biomarker protein signatures discovery, and importance of point-of-care testing for future management. Key words: Cardiac troponin, Creatine kinase, NSTEMI

Point-of-care testing for cardiac markers in acute coronary syndromes and heart failure

Advances in technologies for immunoassay testing have enabled the development of 15-minute whole-blood assays for cardiac markers in the evaluation of patients with acute coronary syndromes (ACS) and congestive heart failure. In many cases, the analytical performance of these assays is equivalent to that of testing in the central laboratory. Rapid whole-blood point-of-care assays for troponin, creatine kinase isoenzyme CK-MB, myoglobin, and B-type natriuretic peptides have facilitated efforts to restructure conventional approaches to ACS and heart failure in the emergency room. Improvements in outcomes, including decreased emergency room and hospital length-of-stay, decreased overall cost, and earlier discharge of low-risk patients, have been documented following implementation of these technologies.