A new simple risk score in patients with acute chest pain without existing known coronary disease

doi:10.1016/j.ajem.2008.10.023

The American Journal of Emergency Medicine

Volume 28, Issue 2, February 2010, Pages 135-142

https://doi.org/10.1016/j.ajem.2008.10.023 Get rights and content

Abstract

Objective

To derive and validate a prediction rule in patients with acute chest pain (CP) without existing known coronary disease.

Methods

Cohort study including 2233 patients with CP. Based on clinical judgment, 1435 were discharged as very low risk and the remaining 798 underwent exercise tolerance test (ETT). End point: 6-month composite of cardiovascular death, nonfatal myocardial infarction, and revascularization. The prediction rule was derived from a randomly selected test cohort (n = 1106) summing factors of variables selected by multivariate regression analysis: CP score higher than 6 (factor of 3), male gender, age older than 50 years, metabolic syndrome, and diabetes mellitus (factor of 1, for each). The prediction rule was validated in the remaining cohort (n = 1127). All patients with CP were categorized into 3 groups: group A (prediction rule 0-1), B (2-4), or C (5-6). Outcomes and prognostic yield of ETT were compared among each group.

Results

In the test cohort, 55 patients (5%) reached the composite end point. Event rate increased as the prediction rule increased: 1% for group A, 6% for B, and 25% for C (P < .001). This pattern was confirmed in the validation cohort (P < .001). A normal ETT did not significantly improve the high (99%) negative predictive value in group A and did not succeed in excluding the composite end point (17%) in group C.

Conclusions

In patients with acute CP without existing coronary disease, a prediction rule based on clinical characteristics provided a useful method for prognostication with possible implication in decision making.

Introduction

Patients with chest pain (CP) and nondiagnostic initial work-up, including electrocardiogram (ECGs) and serial troponins, and without existing known coronary artery disease are currently considered at low risk of short-term coronary events (<2% of death and/or myocardial infarction) [1], [2]. However, in that large and heterogeneous population with a mean low prevalence of coronary disease, diagnosis of acute coronary syndrome still represents a challenge. In low-risk patients, a stress test aids the evaluation of suspected coronary disease and it is usually performed in the Emergency Department (ED), in the CP unit, or on an outpatient basis shortly after discharge; however, submitting patients to this diagnostic strategy is usually based on unstandardized clinical judgment [2], [3], [4]. In patients with defined acute coronary syndrome, several prediction rules are available for risk stratification [5], [6], [7]; conversely, no study has validated the usefulness of a prediction rule including coronary risk factors [8], [9], [10], [11] in a large cohort of patients with low-risk CP. Moreover, some of the major risk factors for atherosclerosis (eg, hypertension, hypercholesterolemia, obesity, cigarette smoking, family history) have been found to be weakly predictive of the likelihood of coronary events in this population [12], [13]. Recently, a cluster of coronary risk factors defined as metabolic syndrome (MS) have received attention in global cardiovascular risk assessment, similar to the awareness diabetes mellitus (DM) has received [14], [15], [16]. To our knowledge, the usefulness of including MS in the diagnostic work-up of patients with acute CP has not been evaluated. Indeed, no standardized prediction rule is yet available for stratification of patients with low-risk CP in the ED [2], [17]. Thus, the primary goal of this study was to derive and validate in an ED a clinical prediction rule for prognostication in patients with low-risk CP.

Section snippets

Patient selection

Consecutive adult patients with CP who presented to our ED (tertiary care teaching hospital), during the years 2002 to 2005, with normal ECG and normal troponin levels were admitted to the CP unit and considered for the study [2]. Patients with existing known coronary artery disease or with a life expectancy less than 6 months were excluded from the study. All patients gave their written consent for study participation. The study was approved by the local institutional review board.

Management of patients and study protocol

In the CP

Results

During the years 2002 to 2005, 6396 patients with CP were evaluated (Fig. 1). Of these, 3751 were considered at high risk of short-term coronary events and were excluded from the study [19], [20]. The remaining 2645 patients, with normal ECG, were admitted to our CP unit [2], [17]. During the first-line work-up, 389 patients developed ischemic ECG changes, and/or abnormal troponins, and/or wall motion abnormalities at echocardiography; all these patients were considered at high risk of coronary

Discussion

This study showed a new simple clinical risk score, the Florence prediction rule, was accurate in stratifying the cardiovascular risk of patients with CP, without existing known coronary disease, and initial negative work-up, usually considered at low risk for future coronary events. The clinical prediction rule, composed of 5 independent prognostic variables (CP score higher than 6, male gender, age older than 50 years, MS, and DM), identifies 3 groups of patients with a risk ranging from 1%

Conclusions

The present simple clinical prediction rule accurately predicts the risk of coronary events in patients with acute CP and normal ECG, without existing known coronary disease, and may be a valuable tool for guiding their management by a threshold approach to clinical decision making [34].

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Cited by (21)

A clinical score to obviate the need for cardiac stress testing in patients with acute chest pain and negative troponins
2016, American Journal of Emergency Medicine
Citation Excerpt :
However, although tested in subjects with undifferentiated chest pain [3,16,17], these scores were not specifically developed for low-risk patients with acute chest pain, non-diagnostic ECGs, and negative troponin levels, which constitute the most challenging subset from the diagnostic point of view. In addition, these and other previous prediction rules [11–14,18–22] did not consider the extent to which further investigations led to changes in management, precluding subsequent events in patients considered at low risk. We were interested not only in evaluating the risk of coronary events but also in ascertaining the need for further cardiac testing and in establishing a very low likelihood of symptomatic CAD.
Although cardiac stress testing may help establish the safety of early discharge in patients with suspected acute coronary syndromes and negative troponins, more cost-effective strategies are necessary. We aimed to develop a clinical prediction rule to safely obviate the need for cardiac stress testing in this setting.
A decision rule was derived in a prospective cohort of 3001 patients with acute chest pain and negative troponins, and validated in a set of 1473 subjects. The primary end point was a composite of positive cardiac stress testing (in the absence of a subsequent negative coronary angiogram), positive coronary angiography, or any major coronary events within 3 months.
A score chart was built based on 7 variables: male sex (+ 2), age (+ 1 per decade from the fifth decade), diabetes mellitus (+ 2), hypercholesterolemia (+ 1), prior coronary revascularization (+ 2), type of chest pain (typical angina, + 5; non-specific chest pain, − 3), and non-diagnostic repolarization abnormalities (+ 2). In the validation set, the model showed good discrimination (c statistic = 0.84; 95% confidence interval, 0.82-0.87) and calibration (Hosmer-Lemeshow goodness-of-fit test, P= .34). If stress tests were avoided in patients in the validation sample with a sum score of 0 or lower, the number of referrals would be reduced by 23.4%, yielding a negative predictive value of 98.8% (95% confidence interval, 97.0%-99.7%).
This novel prediction rule based on a combination of readily available clinical characteristics may be a valuable tool to decide whether stress testing can be reliably avoided in patients with acute chest pain and negative troponins.
Comparison of exercise electrocardiogram and exercise echocardiography in intermediate-risk chest pain patients
2015, American Journal of Emergency Medicine
The novel exercise computer-assisted high-frequency QRS analysis (HF/QRS) has demonstrated improved sensitivity and specificity over the conventional ST/electrocardiogram-segment analysis (ST/ECG) in the detection of myocardial ischemia. The aim of the present study was to compare the diagnostic value of the validated exercise echocardiography (ex-Echo) with the novel exercise ECG (ex-ECG) including HF/QRS and ST/ECG analysis.
A prospective cohort study was conducted in the emergency department of a tertiary care teaching Hospital. Patients with chest pain (CP), normal resting ECGs, troponins, and echocardiography, labeled as “intermediate-risk” for adverse coronary events, underwent the novel ex-ECG and ex-Echo. An ST-segment depression of at least 2 mV or at least 1 mV when associated with CP was considered as an index of ischemia, as well as a decrease of at least 50% in HF/QRS intensity, or new wall motion abnormalities on ex-Echo. Exclusion criteria were QRS duration of at least 120 milliseconds, poor echo-acoustic window, and inability to exercise. Patients were followed up to 3 months. The end point was the composite of coronary stenoses of 50% or greater at angiography or acute coronary syndrome, revascularization, and cardiovascular death on the 3-month follow-up.
Of 188 patients enrolled, 18 achieved the end point. The novel ex-ECG and ex-Echo showed comparable negative predictive value (97% vs 96%; P = .930); however, sensitivity was 83% vs 61%, respectively (P = .612), and specificity was 64% vs 92%, respectively,(P = .026). The areas on receiver operating characteristic analysis were comparable (ex-ECG: 0.734 [95% confidence interval, or CI, 0.62-0.85] vs ex-Echo: 0.767 [CI, 0.63-0.91]; C statistic, P = .167). On multivariate analysis, both ex-ECG (hazard ratio, 5; CI, 1-20; P = .017) and ex-Echo (HR, 12; CI, 4-40; P < .001) were predictors of the end point.
In intermediate-risk CP patients, the novel ex-ECG including HF/QRS added to ST/ECG analysis was a valuable diagnostic tool and might be proposed to avoid additional imaging. However, the novel test needs additional study before it can be recommended as a replacement for current techniques.
External validation of new risk prediction models is infrequent and reveals worse prognostic discrimination
2015, Journal of Clinical Epidemiology
To evaluate how often newly developed risk prediction models undergo external validation and how well they perform in such validations.
We reviewed derivation studies of newly proposed risk models and their subsequent external validations. Study characteristics, outcome(s), and models' discriminatory performance [area under the curve, (AUC)] in derivation and validation studies were extracted. We estimated the probability of having a validation, change in discriminatory performance with more stringent external validation by overlapping or different authors compared to the derivation estimates.
We evaluated 127 new prediction models. Of those, for 32 models (25%), at least an external validation study was identified; in 22 models (17%), the validation had been done by entirely different authors. The probability of having an external validation by different authors within 5 years was 16%. AUC estimates significantly decreased during external validation vs. the derivation study [median AUC change: −0.05 (P < 0.001) overall; −0.04 (P = 0.009) for validation by overlapping authors; −0.05 (P < 0.001) for validation by different authors]. On external validation, AUC decreased by at least 0.03 in 19 models and never increased by at least 0.03 (P < 0.001).
External independent validation of predictive models in different studies is uncommon. Predictive performance may worsen substantially on external validation.
SCCT guidelines on the use of coronary computed tomographic angiography for patients presenting with acute chest pain to the emergency department: A Report of the society of cardiovascular computed tomography guidelines committee
2014, Journal of Cardiovascular Computed Tomography
Citation Excerpt :
There are many criteria that have been proposed to augment clinical judgment in the assessment of risk of major adverse cardiac events or the likelihood of ACS. These include the Thrombolysis in Myocardial Infarction (TIMI) risk score, Goldman criteria, the ACC/AHA guidelines for management of unstable angina and non–ST-segment elevation of myocardial infarction likelihood of ACS categories, and the HEARTS score)5,14–16 However, the dilemma that ED physicians face is that although several risk stratification tools5,6,14,15,17–25have been developed based on clinical presentation and risk factors, they only provide estimates of the likelihood of ACS with many studies demonstrating that history and physical examination are unreliable in excluding ACS26–28. Consequently, the latest AHA scientific statement on testing of low-risk patients presenting to the emergency department with chest pain recommends additional testing in all patients regardless of risk score after initial evaluation.29
Long-term prognostic value of stress echocardiography in patients presenting to the ED with spontaneous chest pain
2014, American Journal of Emergency Medicine
The aims of this study were to evaluate the long-term prognostic value of stress echocardiography (SE) in patients evaluated in emergency department (ED) and to determine SE parameters that best predicted outcome.
Between June 2008 and July 2012, 626 patients with an episode of spontaneous chest pain underwent SE (exercise stress echocardiography or dobutamine stress echocardiography [DSE]). Between December 2012 and January 2013, all patients were contacted to verify the occurrence of cardiac events. Patients were divided in 3 subgroups according to peak stress Wall Motion Score Index (pWMSI): normal peak wall motion (pWMSI, 1; group A1), mild to moderate peak asynergy (pWMSI, 1.1-1.7; group A2), and severe peak asynergy (pWMSI, > 1.7; group A3).
Stress echocardiography showed inducible ischemia in 159 patients (25%); it was negative in 425 (68%) and inconclusive in 42 (7%). Patients with cardiac events more frequently showed inducible ischemia (50% vs 26%; P = .015) compared with patients with good prognosis; a normal SE (14% vs 61%) was significantly less common. At a multivariate regression analysis, an increased pWMSI (relative risk: 9.816, 95% confidence interval: 3.665-26.290; P < .0001) was independently associated with a bad outcome. Cumulative event-free survival was significantly worse with an increasing degree of peak wall motion asynergy (99% in group A1; 96%, group A2; and 88% in group A3; P = .011 between A1 and A2 groups, P = .012 between A2 and A3 groups, and P < .0001 between A1 and A3 groups).
Stress echocardiography showed an optimal prognostic value among ED patients evaluated for chest pain. The presence of an extensive asynergic area at peak stress was associated with an adverse prognosis.
Short- and long-term cardiac events in patients with chest pain with or without known existing coronary disease presenting normal electrocardiogram
2012, American Journal of Emergency Medicine
The aim of this study is to evaluate incidence of adverse cardiac events in patients with chest pain with or without known existing coronary disease presenting normal electrocardiogram (ECG) and initial troponin.
Prospective, nonrandomized study enrolled low-risk patients with normal ECG and troponin on admission who underwent observation and/or stress testing by unstandardized clinical judgment. Patients who experienced recurrent angina or positive ECGs or positive troponins during observation or patients with positive stress testing were admitted; otherwise, they were discharged.
The end points are cardiac events at short- and long-term follow-up including cardiovascular death, myocardial infarction, unstable angina, and revascularization.
Of 5656 patients considered, 1732 with ischemic ECG were initially admitted and, therefore, excluded from the analysis; 2860 with pleuritic chest pain and normal ECG were discharged; 1064 with visceral chest pain and normal ECG were enrolled. Patients with known coronary disease (45%) were older and likely presented known vascular disease. Patients with known vascular disease, older age, female sex, diabetes mellitus, and lower chest pain score were likely managed with observation. In patients with known coronary disease as compared with patients without, overall cardiac events account for 35% vs 14%, respectively (P < .001), as follows: in-hospital, 23% vs 10%, (P < .001); 1 month, 4% vs 2% (P = .133); and 9.9 ± 4.9 months, 8% vs 2%, respectively (P < .001).
One-third of patients with chest pain with known coronary disease, negative ECG, and biomarkers were subsequently found to have adverse cardiac events. The value of this research for an emergency medicine audience could be extended to all clinicians and general practitioners beyond cardiologists.

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Orginal ContributionA new simple risk score in patients with acute chest pain without existing known coronary disease

Abstract

Objective

Methods

Results

Conclusions

Introduction

Section snippets

Patient selection

Management of patients and study protocol

Results

Discussion

Conclusions

J Am Coll Cardiol

J Am Coll Cardiol

Am J Cardiol

J Clin Epidemiol

Am Heart J

J Am Coll Cardiol

Am J Cardiol

J Am Coll Cardiol

A classification of unstable angina revisited

Circulation

Evaluation of the patient with acute chest pain

N Engl J Med

Safety and utility of exercise testing in emergency room chest pain centers. An advisory from the Committee on Exercise, Rehabilitation, and Prevention, Council on Clinical Cardiology, American Heart Association

Circulation

The TIMI risk score for unstable angina/non-ST-elevation MI. A method for prognostication and therapeutic decision making

JAMA

Prediction of risk of death and myocardial infarction in the six months after presentation with acute coronary syndrome: prospective multinational observational study (GRACE)

BMJ

TIMI risk score for ST-elevation myocardial infarction: a convenient, bedside, clinical score for risk assessment at presentation

Circulation

Age and outcome with contemporary thrombolytic therapy: results from the GUSTO-I trial

Circulation

Sex, clinical presentation, and outcome in patients with acute coronary syndromes. Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes IIb Investigators

N Engl J Med

A tool for judging coronary care unit admission appropriateness, valid for real-time and retrospective use: a time-insensitive predictive instrument (TIPI) for acute cardiac ischemia multicenter study

Med Care

Orginal Contribution
A new simple risk score in patients with acute chest pain without existing known coronary disease