The association between pretest probability of coronary artery disease and stress test utilization and outcomes in a chest pain observation unit

Glucose and high-sensitivity troponin T predict a low risk of major adverse cardiac events in emergency department chest pain patients

Background. Glucose is emerging as a biomarker for early and safe rule-out of acute myocardial infarction in emergency department (ED) chest pain patients. We evaluated the diagnostic accuracy of dual testing with high sensitivity TnT (hs-cTnT) and glucose for prediction of major adverse cardiac events (MACE) within 30 days. Methods. This was a secondary analysis of a single-center prospective observational study of 1167 ED chest-pain patients with hs-cTnT and glucose testing at presentation (0 h), and hs-cTnT 1 h later. We tested the addition of glucose <5.6 mmol/L to three MACE rule-out strategies: hs-cTnT <5 ng/L, ≤14 ng/L or a 0 h/1h algorithm, i.e. initial hs-cTnT <12 ng/L with a 1 h change of <3 ng/L. We also tested the addition of glucose ≥11mmol/L to three rule-in strategies: hs-cTnT ≥52 ng/L, a 1 h change ≥5 ng/L or hs-cTnT >14 ng/L. The outcomes were 30-day MACE and 30-day MACE without UA. Results. Two dual-testing approaches reached our target NPV for rule-out: A 0 h hs-cTnT ≤14 ng/L and glucose <5.6 mmol/L identified 252 patients (24.4%) with a 98.8% NPV for 30-day MACE and 99.6% for MACE without UA. The 0 h/1h hs-cTnT algorithm combined with glucose identified 240 patients (23.2%) with a 99.2% NPV for 30-day MACE and 100.0% for MACE without UA. No dual rule-in strategy performed better than using hs-cTnT alone. Conclusions. A combination of hs-cTnT and blood glucose at presentation can be used to identify almost ¼ of ED chest pain patients with a very low risk of 30-day MACE where further testing is not needed. Adding glucose did not improve the rule-in of 30-day MACE.

Received care compared to ADP-guided care of patients admitted to hospital with chest pain of possible cardiac origin

Purpose

To assess the extent to which accelerated diagnostic protocols (ADPs), compared to traditional care, identify patients presenting to emergency departments (EDs) with chest pain who are at low cardiac risk and eligible for early ED discharge.

Patients and methods

Retrospective study of 290 patients admitted to hospital for further evaluation of chest pain following negative ED workup (no acute ischemic electrocardiogram [ECG] changes or elevation of initial serum troponin assay). Demographic data, serial ECG and troponin results, Thrombolysis in Myocardial Infarction (TIMI) score, cardiac investigations, and outcomes (confirmed acute coronary syndrome [ACS] at discharge and major adverse cardiac events [MACEs]) over 6 months of follow-up were analyzed. A validated ADP (ADAPT-ADP) was retrospectively applied to the cohort, and processes and outcomes of ADP-guided care were compared with those of care actually received.

Results

Patients had mean (±SD) TIMI score of 1.8 (±1.7); six (2.0%) patients were diagnosed with ACS at discharge. At 6 months, one patient (0.3%) re-presented with ACS and two (0.6%) died of non-coronary causes. The ADAPT-ADP defined 97 (33.4%) patients as being at low risk and eligible for early ED discharge, but who instead incurred mean hospital stay of 1.5 days, with 40.2% in telemetry beds, and 21.6% subject to non-invasive testing with only one positive result for coronary artery disease. None had a discharge diagnosis of ACS or developed MACE at 6 months.

Conclusion

Compared to traditional care, application of the ADAPT-ADP would have allowed one-third of chest pain patients with initially negative investigations in ED to have been safely discharged from ED.

Chest pain triage: Current trends in the emergency departments in the United States

Chest pain is one of the most common complaints in the emergency department (ED). Over the past decade, there has been a significant shift in the approach to patients with chest pain in the ED. With the development of improved cardiac biomarkers, the validation of clinical scoring systems, and an increasing emphasis on shared patient medical decision making, increasing numbers of patients in the ED are being evaluated without requiring admission to the hospital.

Value of the coronary artery disease consortium rule in patients with acute chest pain and negative troponins referred for exercise stress testing

OBJECTIVE

To assess the value of the pretest probability (PTP) of coronary artery disease (CAD) for predicting stress testing results and coronary events in patients with acute chest pain and negative troponins.

PATIENTS AND METHODS

A total of 3527 patients without a history of CAD referred to our chest pain unit with suspected acute coronary syndromes, nondiagnostic ECGs, and negative troponin levels underwent exercise stress testing. PTP was estimated with the CAD consortium prediction rule, and was categorized as low (<15%), low-intermediate (15-65%), intermediate-high (66-85%), and high (>85%). The endpoints were the presence of signs of inducible myocardial ischemia on stress testing and the occurrence of coronary events within 6 months.

RESULTS

The probability of exercise-induced myocardial ischemia was 2.6, 12.6, 42.9, and 82.1% in patients with low, low-intermediate, intermediate-high, and high PTP, respectively (Ptrend<0.001). The cumulative rate of coronary events within 6 months was also significantly lower in patients with low PTP of CAD (0.8%) than in those with low-intermediate (6.9%), intermediate-high (32.5%), or high PTP (66.7%) (Ptrend<0.001). Per 10% increment in PTP of CAD, the adjusted odds ratios for inducible myocardial ischemia and coronary events within 6 months were, respectively, 1.71 (95% confidence interval: 1.61-1.85) and 1.87 (95% confidence interval: 1.74-2.01).

CONCLUSION

PTP was associated strongly with the likelihood of exercise-induced myocardial ischemia and coronary events in patients with suspected acute coronary syndromes and negative troponins. The yield of stress testing in the subset of patients with low PTP was very low.

Association of Early Stress Testing with Outcomes for Emergency Department Evaluation of Suspected Acute Coronary Syndrome

BACKGROUND

Professional society guidelines suggest early stress testing (within 72 hours) after an emergency department (ED) evaluation for suspected acute coronary syndrome (ACS). However, there is increasing concern that current practice results in over-testing without evidence of benefit. We test the hypothesis that early stress testing improves outcomes.

METHODS

We analyzed prospectively collected data from 9 EDs on patients with suspected ACS, 1999-2001. We excluded patients with an ED diagnosis of ACS. The primary outcome was 30-day major adverse cardiac events (MACEs), including all-cause death, acute myocardial infarction, and revascularization. We used the HEART score to determine pretest ACS risk (low, intermediate, and high). To mitigate potential confounding, patients with and without early stress testing were matched within pretest risk strata in a 1:2 ratio using propensity scores.

RESULTS

Of 7127 potentially eligible patients, 895 (13%) received early stress testing. The analytic cohort included 895 patients with early stress testing matched to 1790 without early stress testing. The overall 30-day MACE rate in both the source and analytic population was 3%. There were no baseline imbalances after propensity score matching (P > 0.1 for more than 30 variables). There was no association between early stress testing and 30-day MACE [odds ratio, 1.0; 95% confidence interval (CI), 0.6-1.7]. There was no effect modification by pretest risk (low: odds ratio, 1.0; 95% CI, 0.2-3.7; intermediate: 1.2; 95% CI, 0.6-2.6; high: 0.4; 95% CI, 0.1-1.6).

CONCLUSIONS

Early stress testing is not associated with reduced MACE in patients evaluated for suspected ACS. Early stress testing may have limited value in populations with low MACE rate.

Inter-rater Reliability of the Diamond & Forrester Score in Emergency Department Chest Pain Observation Unit Patients

BACKGROUND

Cardiology consensus guidelines recommend use of the Diamond & Forrester (D&F) score in augmenting the decision to pursue stress testing. We have recently shown that it may have value in safely reducing stress utilization in an emergency department chest pain unit (CPU). However, full application necessitates demonstration of a good inter-rater reliability of the D&F score in the CPU setting. We hypothesized that D&F pretest probability would have good inter-rater reliability in CPU patients.

METHODS

This was a chart review of randomly selected patients from a previously collected prospective observational trial of admitted CPU patients in a large-volume academic urban emergency department. Inclusion criteria were: age>18 years, American Heart Association low/intermediate risk, nondynamic electrocardiograms, and normal initial troponin I. Exclusion criteria were: age>75 years with coronary artery disease. A D&F score for likelihood of coronary artery disease was calculated on each patient by 2 trained chart abstractors using a standardized data abstraction instrument. Abstractors were trained to specifically categorize presenting symptoms as fitting 1 of 3 types of chest pain symptoms: nonanginal, atypical, or anginal based on previously published prespecified criteria. Approximately 20% of charts in a CPU registry were abstracted by 2 chart abstractors who were blind to each other's categorization, the patient outcomes, and the study hypothesis. The primary outcome was the kappa statistic for agreement between the 2 raters.

RESULTS

The charts of 705 random patients were reviewed. The mean age was 55.1±11.8 years, 52% were female. Forty four percentage of patients received stress testing, and 2.4% of patients had acute coronary syndrome. The mean D&F score was 39±24. There was good inter-rater agreement of chest pain characteristics (κ=0.77, 95% confidence interval, 0.72-0.81; P<0.01).

CONCLUSION

This study supports the use of the D&F score as a reliable indicator of pretest probability in CPU patients by demonstrating that there is good inter-rater reliability. Prospective validation is necessary at the point of patient assessment, in conjunction with application of the D&F score to augment stress utilization decision making.

Diagnostic yield of routine noninvasive cardiovascular testing in low-risk acute chest pain patients

Contemporary professional society recommendations for patients presenting to the emergency department with acute chest pain and low clinical risk encourage noninvasive testing for coronary artery disease (CAD) before, or shortly after, discharge from the emergency department. Recent reports indicate that a strategy of universal testing has a low diagnostic yield and may not be necessary. We examined data from a prospective cohort of patients who underwent evaluation of acute chest pain in our chest pain evaluation center (CPEC). Patients presenting with normal initial electrocardiogram and cardiac injury markers were eligible for observation and noninvasive testing for CAD in our CPEC. All patients were asked to participate in the prospective registry. The 213 subjects who consented were young, obese, and predominantly women (mean age 43.8 ± 12.5, mean body mass index of 30.8 ± 7, 64.8% women). Prevalence of diabetes was 10.3% (hypertension 37.1%, hyperlipidemia 17.8%, and current tobacco use 23.5%) Exercise treadmill testing was the primary method of evaluation (n = 104, 49%) followed by computed tomography coronary angiography (n = 58, 27%) and myocardial perfusion imaging (n = 20, 9%). Of 203 patients who underwent testing, 11 had abnormal test results, 4 of whom had obstructive CAD based on invasive coronary angiography. The positive predictive value for obstructive CAD after an abnormal test was 45.5%, and the overall diagnostic yield for obstructive CAD was 2.5%. In conclusion, in patients with acute chest pain evaluated in a CPEC, the yield of routine use of noninvasive testing for CAD was minimal and the positive predictive value of an abnormal test was low.