Validation of the Vancouver Chest Pain Rule using troponin as the only biomarker: a prospective cohort study

Early Rule-Out and Rule-In Strategies for Myocardial Infarction

BACKGROUND

Patients with chest pain comprise a large proportion of emergency presentations and place a major burden on healthcare resources. Therefore, efforts to safely and rapidly identify those with and without acute myocardial infarction (AMI) are needed. The challenge for clinicians is to accurately identify patients with acute coronary syndromes, while balancing the need to safely and rapidly reassure and discharge those without serious conditions.

CONTENT

This review summarizes the evidence to date on optimum accelerated strategies for the rule-in and rule-out of AMI, using strategies focused on optimum use of troponin results. Evidence based on both sensitive and highly sensitive troponin assay results is presented. The use of novel biomarkers is also addressed and the combination of biomarkers with other clinical information in accelerated diagnostic strategies is discussed.

SUMMARY

The majority of patients, who are not at risk of myocardial infarction or other serious harm, may be suitable for discharge directly from the emergency setting using approaches focused on troponin algorithms and accelerated diagnostic protocols. Evidence about the clinical and health economic impact of use of such strategies is needed, as they may have major benefits for both patients and healthcare providers.

Best Clinical Practice: Current Controversies in the Evaluation of Low-Risk Chest Pain with Risk Stratification Aids. Part 2

BACKGROUND

Chest pain accounts for 10% of emergency department (ED) visits annually, and many of these patients are admitted because of potentially life-threatening conditions. A substantial percentage of patients with chest pain are at low risk for a major cardiac adverse event (MACE).

OBJECTIVE

We investigated controversies in the evaluation of patients with low-risk chest pain, including clinical scores, decision pathways, and shared decision-making.

DISCUSSION

ED patients with chest pain who have negative biomarker results and nonischemic electrocardiograms are at low risk for MACE. With the large number of chest pain patients evaluated in the ED, several risk scores and pathways are in use based on history, electrocardiographic results, and biomarker results. The Thrombolysis in Myocardial Infarction and Global Registry of Acute Coronary Events scores are older rules with validation; however, they do not have adequate sensitivity or are not easy to use in the ED. The Vancouver chest pain and North American chest pain rules may be used for patients with undifferentiated chest pain in the ED. The Manchester Acute Coronary Syndromes rule uses eight factors, several of which are not available in the United States. The history, electrocardiography, age, risk factors, and troponin (HEART) score and pathway are easy to use, have high sensitivity and negative predictive values, and have better discriminatory capability for categorization. The use of pathways with shared decision-making involves the patient in management, shortens the duration of stay, and decreases risk to both the patient and the provider.

CONCLUSIONS

Risk stratification of ED patients with chest pain has evolved, and there are many tools available. The HEART pathway, designed for ED use, has several attributes that provide safe and efficient care for patients with chest pain.

Validation of the new Vancouver Chest Pain Rule in Asian chest pain patients presenting at the emergency department

Objectives

The new Vancouver Chest Pain (VCP) Rule recommends early discharge for chest pain patients who are at low risk of developing acute coronary syndrome (ACS), and thus can be discharged within 2 hours of arrival at the emergency department (ED). This study aimed to assess the performance of the new VCP Rule for Asian patients presenting with chest pain at the ED.

Methods

This prospective cohort study involved patients attended to at the ED of a large urban centre. Patients of at least 25 years old, presenting with stable chest pain and a non-diagnostic ECG, and with no history of active coronary artery disease were included in the study. The main outcome measures were cardiac events, angioplasty, or coronary artery bypass within 30 days of enrolment.

Results

The study included 1690 patients from 27 August 2000 to 1 May 2002, with 661 patients fulfilling the VCP criteria. Of those for early discharge, 24 had cardiac events and 13 had angioplasty or bypass at 30 days, compared to 91 and 41, respectively, for those unsuitable for discharge. This gave the rule a sensitivity of 78.1% for cardiac events, including angioplasty and bypass. Specificity was 41.0%, and negative predictive value (NPV) was 94.4%.

Conclusion

We found the new VCP Rule to have moderate sensitivity and poor specificity for adverse cardiac events in our population. With an NPV of less than 100%, this means that a small proportion of patients sent home with early discharge would still have adverse cardiac events.

Relationship Between Physiological Parameters and Acute Coronary Syndrome in Patients Presenting to the Emergency Department With Undifferentiated Chest Pain

The investigators of this study sought to examine whether abnormal physiological parameters are associated with increased risk for acute coronary syndrome (ACS) in patients presenting to the emergency department (ED) with chest pain.

METHODS

We used prospectively collected data on adult patients presenting with suspected ACS in 2 EDs in Australia and New Zealand. Trained research nurses collected physiological data including temperature, respiratory rate, heart rate, and systolic blood pressure (SBP) on presentation to the ED. The primary endpoint was ACS within 30 days of presentation, as adjudicated by cardiologists using standardized guidelines. The prognostic utility of physiological parameters for ACS was examined using risk ratios.

RESULTS

Acute coronary syndrome was diagnosed in 384 of the 1951 patients (20%) recruited. Compared with patients whose SBP was between 100 and 140 mm Hg, patients with an SBP of lower than 100 mm Hg or higher than 140 mm Hg were 1.4 times (95% confidence interval, 1.2-1.7) more likely to have ACS. Similarly, compared with patients whose temperature was between 36.5°C and 37.5°C, patients with temperature of lower than 36.5°C or higher than 37.5°C were 1.4 times (95% confidence interval, 1.1-1.6) more likely to have ACS. Heart rate and respiratory rate were not predictors of ACS.

CONCLUSIONS

Patients with abnormal temperature or SBP were slightly more likely to have ACS, but such risk was of too small a magnitude to be useful in clinical decision making. Other physiological parameters (heart rate and respiratory rate) had no prognostic value. The use of physiological parameters cannot reliably confirm or rule out ACS.