The Journal of Emergency Medicine, Vol. -, No. -, pp. 1–6, 2016 Ó 2016 Elsevier Inc. All rights reserved. 0736-4679/$ - see front matter
http://dx.doi.org/10.1016/j.jemermed.2016.09.005
Brief Reports EMERGENCY DEPARTMENT PRESENTATION OF PATIENTS WITH SPONTANEOUS CORONARY ARTERY DISSECTION Rachel A. Lindor, MD, JD,* Marysia S. Tweet, MD,† Kiran A. Goyal,* Christine M. Lohse, MS,‡ Rajiv Gulati, MD, PHD,† Sharonne N. Hayes, MD,† and Annie T. Sadosty, MD* *Department of Emergency Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota, †Department of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, Minnesota, and ‡Department of Health Sciences Research, Mayo Clinic College of Medicine, Rochester, Minnesota Reprint Address: Rachel A. Lindor, MD, JD, Mayo Clinic College of Medicine, 200 1st St. SW, Rochester, MN 55905
, Abstract—Background: Spontaneous coronary artery dissection (SCAD) is an infrequently recognized but potentially fatal cause of acute coronary syndrome (ACS) that disproportionately affects women. Little is currently known about how patients with SCAD initially present. Objectives: We sought to describe patients who presented to the emergency department (ED) with symptoms of SCAD to improve providers’ awareness and recognition of this condition. Patients and Methods: We performed a retrospective medical record review of all patients who presented to the ED of a single academic medical center from January 1, 2002 through October 31, 2015 and were subsequently diagnosed with SCAD by angiography. These patients were identified by International Classification of Diseases, Ninth Revision codes and a Boolean search of the diagnosis field of the medical record. Data regarding patients’ presentations and course were abstracted by two independent reviewers. Results: We identified 20 episodes of SCAD involving 19 patients, all of whom were female. The majority of patients had 0–1 conventional cardiovascular disease risk factors. Most patients had chest pain (85%), initial electrocardiograms without evidence of ischemia (85%), and elevated initial troponin (72%). The most common diagnosis in providers’ differential was acute coronary syndrome (ACS). Conclusion: Patients with SCAD present with similar symptoms compared to patients with ACS caused by atherosclerotic disease, but have different risk profiles. Providers should consider SCAD in patients presenting with symptoms concerning for ACS, especially in younger female patients
without traditional cardiovascular disease risk factors, as their risk may be significantly underestimated with commonly used ACS risk-stratifiers. Ó 2016 Elsevier Inc. All rights reserved. , Keywords—spontaneous coronary artery dissection; acute coronary syndrome
INTRODUCTION Background Spontaneous coronary artery dissection (SCAD), defined as a nontraumatic and noniatrogenic separation of the coronary artery walls in the absence of atherosclerosis, is an increasingly recognized cause of acute coronary syndrome (ACS) (1). Arterial wall dissection or vessel wall hematoma may occlude the coronary arterial lumen and lead to subsequent myocardial infarction (MI) or ischemia (2). Compared to ACS related to atherosclerotic coronary heart disease, ACS related to SCAD disproportionately affects young women without traditional cardiovascular disease (CVD) risk factors. SCAD risk factors include pregnancy and postpartum status, systemic vasculopathies such as fibromuscular dysplasia, connective tissue disorders, and recent significant physical or emotional stressors (3). Though previously thought to be quite rare, improved
RECEIVED: 18 May 2016; FINAL SUBMISSION RECEIVED: 3 August 2016; ACCEPTED: 5 September 2016 1
2
R. A. Lindor et al.
techniques for intracoronary imaging now suggest that SCAD may be the cause of up to 4% of all ACS and up to 25% of MIs in women under age 50 years (4). Despite better understanding of the prevalence and risk factors for the disease, SCAD continues to be frequently missed or misdiagnosed (4). Importance Failure to consider SCAD as a potential cause for symptoms consistent with ACS may have significant consequences. First, because SCAD often arises in individuals without traditional CVD risk factors, patients presenting with SCAD-related symptoms may be deemed by clinicians to be low risk for ACS and receive an abbreviated (or no) cardiac evaluation. Second, because the preferred treatment for stable patients is conservative medical management, failure to consider SCAD early in a patient’s course may result in patients undergoing unnecessary attempts at revascularization or receiving medical therapy mistakenly aimed at atherosclerotic disease risk factors (3). Goals of this Investigation
identified by a Boolean search of ‘‘spontaneous’’ and ‘‘coronary’’ and ‘‘dissection’’ within the diagnosis field of the EMR were identified. The results of both of these searches were limited to include only patients evaluated in the ED within 2 weeks of their diagnosis of SCAD. Patients with iatrogenic coronary artery dissection and coexistent atherosclerotic coronary artery disease were excluded, as coronary dissection in these patients represents a different disease process. Together, these search strategies identified 1684 patients, 19 of whom were included in the final study population representing a total of 20 separate SCAD episodes that were confirmed by angiography. A flow diagram showing how the study population was derived is provided in Figure 1. The majority of patients in the initial search did not have SCAD but were identified because the Boolean search tool did not consistently
1684 89 with no research consent
1595 1050 with no ED visit within 2 weeks
The goal of this investigation was to describe the initial presentation of patients with SCAD, including their symptoms, vital signs, electrocardiogram (ECG) and laboratory findings, management, and outcomes. Greater understanding of the range of presenting symptoms, risk factors, and early treatment of ACS due to SCAD may serve to increase physicians’ awareness and improve their management of patients with SCAD. MATERIALS AND METHODS
545 160 with no dissec on of any type
385 109 with SCAD in se ng of severe CAD
276 108 with SCAD in differen al but not final diagnosis
Study Design and Setting This was a retrospective chart review using the electronic medical record (EMR) to identify consecutive adult patients seen in the emergency department (ED) for SCAD-related symptoms. The study was conducted at an academic medical center with approximately 70,000 annual visits. Records from January 1, 2002, when the ED began using electronic diagnosis coding, through October 31, 2015 were included. The institutional review board approved this study.
168 73 dissec ons of structures other than coronaries
95 58 cases of iatrogenic coronary dissec on
37 17 duplicate records
Setting and Selection of Participants The EMR was searched using two different tools. First, all patients with coronary artery dissection, identified by International Classification of Diseases, Ninth Revision (ICD-9) code 414.12, were identified. Second, all patients
20 Figure 1. Selection of study participants from initial search of electronic medical record number of patient visits.
Spontaneous Coronary Artery Dissection in the ED
restrict the search terms to the diagnosis field. In addition, there is no ICD-9 code specifically for spontaneous coronary artery dissection, so the original ICD-9 search included many patients who had an iatrogenic coronary artery dissection. Methods and Measurements Utilizing widely accepted chart review methods, a standardized data collection form was developed and tested in a 5-patient pilot by two investigators (5). Ambiguously recorded data were discussed with a senior investigator (ATS), the data collection tool was revised, and two physician investigators (RAL, MST) independently abstracted data from every patient by reviewing the individual charts. For descriptive data recorded differently by the providers working with a single patient (e.g., staff physician, resident physician, nurse), all descriptors were recorded. For binary data, such as the presence of individual CVD risk factors, the data fields were marked as present if these were noted by any one of the providers caring for the patient. Binary variables that were not specifically mentioned were assumed to be absent. Overall concordance between abstractors was 87.5%, including 90% for risk factors and ECG findings and 73% for laboratory values. All discrepancies were arbitrated by a senior author.
3
two of these risk factors, 4 patients had one risk factor, and 11 patients had none. Additional data regarding patient demographics, presenting vital signs, and initial laboratory results are summarized in Table 1. Symptoms. In 85% of cases, patients presented with a chief complaint of chest pain (n = 17). Other reasons for presentation included cardiac arrest (n = 2) and vomiting (n = 1). Among patients with chest pain, the pain was most frequently described as crushing, heaviness, or pressure (n = 12, 71%), or as sharp (n = 6, 35%). Commonly associated symptoms included nausea (n = 9, 45%), diaphoresis (n = 5, 25%), lightheadedness (n = 5, 25%), and dyspnea (n = 3, 15%). In five cases (25%, 95% CI 10– 49%), patients reported having similar pain previously without seeking evaluation. In the 10 cases in which patient activity at onset was documented, the pain occurred at rest in all cases (100%, 95% CI 66–100%). Vital signs.Most patients had normal vital signs at presentation. Three patients (15%) were tachycardic and 12 patients (60%) were hypertensive. Differential diagnoses. The most common differential diagnoses documented by emergency physicians included ACS or MI (n = 16, 80%), aortic dissection (n = 9, Table 1. Patients’ Risk Factors, Presenting Vital Signs, and Laboratory Findings
Analysis The 95% confidence intervals (CI) were calculated using the score method incorporating a continuing correction (6). Statistical analyses were performed using version 9.3 of the SAS software package (SAS Institute, Cary, NC). RESULTS
Patient Characteristics CAD risk factors Obesity Hypertension Active smoker Hyperlipidemia Previous MI Known CAD
Main Results Cardiovascular disease risk factors. The documented presence of traditional CVD risk factors was assessed in all patients, including current tobacco use, obesity, prior coronary artery disease, hypertension, hyperlipidemia, previous MI, or male gender. Only 5 patients had
5 3 2 2 2 0 Median
Characteristics of the Study Subjects Of the 19 patients identified, all were female, with a mean age of 46 years (range 31–63 years). One patient had two separate episodes of SCAD. Though the search included patients diagnosed with SCAD in the 2 weeks after an ED visit, all patients in our study population were admitted to the hospital from their ED visit and diagnosed with SCAD during initial angiography at that hospitalization.
# Of Patients
Presenting vital signs HR (beats/min) RR (breaths/min) SBP (mm Hg) DBP (mm Hg) Temp ( C) SpO2 (%) Laboratory findings WBC (109/L) Hemoglobin (g/dL) Platelets (109/L) INR Initial troponin T (ng/mL) 3-hour troponin T (ng/mL 6-hour troponin T (ng/mL
% (n = 20) 25 15 10 10 0 0 Range
75 16 141 89 36.7 99
54–116 13–30 124–202 53–116 36.3–37.3 94–00
8.5 13.2 256 1.0 0.08 0.36 0.37
4.5–19.7 12.0–14.3 143–376 0.8–1 0–1.2 0–6.9 0–8.8
CAD = coronary artery disease; MI = myocardial infarction; HR = heart rate; RR = respiratory rate; SBP = systolic blood pressure; DBP = diastolic blood pressure; WBC = white blood cell; INR = international normalized ratio; SpO2 = pulse oximetry.
4
R. A. Lindor et al.
45%), pulmonary embolism (n = 9, 45%), and gastrointestinal cause such as esophageal spasm or reflux (n = 6, 30%). Laboratory findings. Troponin values drawn after a cardiac arrest or catheterization were not included in the analysis. Of the troponin values included, the initial troponin value was elevated in 13 of 18 cases at presentation (72%, 95% CI 46–89%), 16 of 17 cases at 3 h (94%, 95% CI 69–100%), and 14 of 15 cases at 6 h (93%, 95% CI 66–100%). The single patient without troponin elevation throughout the 6-h period reported that her pain had been ongoing for several weeks prior to presentation. ECG findings.The most common ECG findings at presentation, as interpreted by a cardiologist in real time, were a normal ECG (n = 7, 35%, 95% CI 16–59%) or ‘‘non-specific ST abnormality’’ (n = 6, 30%, 95% CI 13–54%), followed by ST elevation (n = 3, 15%, 95% CI 4–39%) and ST depression (n = 1, 5%, 95% CI 0–27%).
involved patients with zero or one atherosclerotic disease risk factor. Commonly used risk-stratification tools such as the HEART score or Emergency Department Assessment of Chest Pain Score, which rely heavily on the presence of atherosclerotic disease risk factors to estimate a patient’s risk of an adverse cardiac event, can inappropriately label SCAD patients as low risk (7,8). Based on these tools, a young peripartum woman with a connective tissue disorder presenting with chest pain may be calculated to be at low risk and discharged from the ED prematurely, despite demonstrating multiple risk factors for SCAD. This is of particular concern because the majority of SCAD patients in this series presented with nonspecific ECG changes, and several did not have elevations in their initial troponin levels. This highlights a limitation of these commonly used risk-assessment tools, which were designed to assess patients’ cardiac risk due to atherosclerotic disease, not all causes of ACS. Limitations
Management/outcomes. Most patients (n = 13, 65%) were admitted to the hospital after their initial ED evaluation. Four patients (20%) were sent directly to coronary angiography, and 3 patients (15%) were admitted to the ED observation unit. No patient was discharged to home. Nine patients were initiated on heparin in the ED prior to final disposition. Three patients received a cardiac stent during the index hospitalization. All patients survived > 30 days past hospital discharge. DISCUSSION Despite increased awareness of and improved diagnostic techniques for SCAD, it is an infrequently considered etiology of chest pain. Data from this single-center study demonstrate that patients with SCAD have a wide variety of presentations, ranging from mild chest pain with normal initial ECGs and troponin levels to isolated vomiting or cardiac arrest. Many patients with SCAD describe their symptoms as similar to those associated with classic angina or MI due to atherosclerotic disease. This is not unexpected, as SCAD-related symptoms at presentation are likely related to myocardial ischemia due to impaired coronary flow, just as in ACS due to underlying atherosclerosis. There are, however, important distinctions between the presentations of patients in our study population and patients with coronary atherosclerosis that may prompt ED providers to consider SCAD earlier in a patient’s course. Most prominently, patients with SCAD often have very different CVD risk-factor profiles than patients with atherosclerotic coronary artery disease. Among the 20 cases in our study cohort, the majority (75%)
This study had several limitations. First, with 20 patient encounters, the study is underpowered to draw strong conclusions regarding the typical presentation of SCAD, and therefore is best used as a qualitative description. Second, the data were collected from ED records, so data collection is dependent on the information recorded. In addition, at our institution, peripartum patients with acute labor-related issues generally present to a separate obstetrical triage area. As a result, our data may underrepresent the association between SCAD and pregnant or postpartum states, as many of these patients would have been missed by the search. In fact, no patients in our data were pregnant or recently pregnant. Finally, the restriction of the search to patients who were diagnosed within 2 weeks of an ED visit may have missed patients who presented with SCAD-related symptoms, were discharged home, and subsequently diagnosed with SCAD elsewhere or later, or not diagnosed at all. CONCLUSIONS The different risk-factor profiles between SCAD and atherosclerotic coronary artery disease suggest that providers should develop and employ a different heuristic approach for considering SCAD in patients with symptoms consistent with ACS. In patients with chest pain or other ACS symptoms but low CVD risk—especially women—providers must have a high level of suspicion for ACS due to SCAD and consider the demographics and conditions associated with SCAD. Doing so may prevent providers from underestimating patients’ cardiovascular risks and improve the recognition of SCAD.
Spontaneous Coronary Artery Dissection in the ED
REFERENCES 1. Yip A, Saw J. Spontaneous coronary artery dissection – a review. Cardiovasc Diagn Ther 2015;5:37–48. 2. Tweet MS, Hayes SN, Sridevi RP, et al. Clinical features, management, and prognosis of spontaneous coronary artery dissection. Circulation 2012;126:579–88. 3. Tweet MS, Gulati R, Hayes SN. What clinicians should know about spontaneous coronary artery dissection. Mayo Clin Proc 2015;90:1125–30. 4. Saw J, Aymong E, Mancini GB, et al. Nonatherosclerotic coronary artery disease in Young Women. Can J Cardiol 2014;30:814–9.
5 5. Kaji AH, Schriger D, Green S. Looking through the retrospectoscope: reducing bias in emergency medicine chart review studies. Ann Emerg Med 2014;64:292–8. 6. Newcombe R. Two-sided confidence intervals for the single proportion: comparison of seven methods. Stat Med 1998;17: 857. 7. Six AJ, Backus BE, Kelder JC. Chest pain in the emergency room: value of the HEART score. Neth Heart J 2008;16:191–6. 8. Than M, Flaws D, Sanders S, et al. Development and validation of the Emergency Department Assessment of Chest pain Score and 2 h accelerated diagnostic protocol. Emerg Med Australas 2014;26: 34–44.
6
R. A. Lindor et al.
ARTICLE SUMMARY 1. Why is this topic important? Spontaneous coronary artery dissection (SCAD) is an under-recognized cause of acute coronary syndrome and is associated with significant morbidity and mortality. 2. What does this study attempt to show? The study attempts to describe the emergency department presentation of patients with SCAD to increase providers’ awareness of this etiology of acute coronary syndrome. 3. What are the key findings? The symptoms of SCAD are nearly indistinguishable from acute coronary syndrome caused by atherosclerotic disease, but it affects people with very different risk factors. 4. How is patient care impacted? SCAD should be considered in patients with symptoms consistent with acute coronary syndrome, even if they lack traditional atherosclerotic disease risk factors, and especially if they have one or more SCAD risk factors, including female gender, connective tissue disorder, antecedent physical or emotional stress, and pregnancy or postpartum status.
http://dx.doi.org/10.1016/j.jemermed.2016.09.005
Brief Reports EMERGENCY DEPARTMENT PRESENTATION OF PATIENTS WITH SPONTANEOUS CORONARY ARTERY DISSECTION Rachel A. Lindor, MD, JD,* Marysia S. Tweet, MD,† Kiran A. Goyal,* Christine M. Lohse, MS,‡ Rajiv Gulati, MD, PHD,† Sharonne N. Hayes, MD,† and Annie T. Sadosty, MD* *Department of Emergency Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota, †Department of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, Minnesota, and ‡Department of Health Sciences Research, Mayo Clinic College of Medicine, Rochester, Minnesota Reprint Address: Rachel A. Lindor, MD, JD, Mayo Clinic College of Medicine, 200 1st St. SW, Rochester, MN 55905
, Abstract—Background: Spontaneous coronary artery dissection (SCAD) is an infrequently recognized but potentially fatal cause of acute coronary syndrome (ACS) that disproportionately affects women. Little is currently known about how patients with SCAD initially present. Objectives: We sought to describe patients who presented to the emergency department (ED) with symptoms of SCAD to improve providers’ awareness and recognition of this condition. Patients and Methods: We performed a retrospective medical record review of all patients who presented to the ED of a single academic medical center from January 1, 2002 through October 31, 2015 and were subsequently diagnosed with SCAD by angiography. These patients were identified by International Classification of Diseases, Ninth Revision codes and a Boolean search of the diagnosis field of the medical record. Data regarding patients’ presentations and course were abstracted by two independent reviewers. Results: We identified 20 episodes of SCAD involving 19 patients, all of whom were female. The majority of patients had 0–1 conventional cardiovascular disease risk factors. Most patients had chest pain (85%), initial electrocardiograms without evidence of ischemia (85%), and elevated initial troponin (72%). The most common diagnosis in providers’ differential was acute coronary syndrome (ACS). Conclusion: Patients with SCAD present with similar symptoms compared to patients with ACS caused by atherosclerotic disease, but have different risk profiles. Providers should consider SCAD in patients presenting with symptoms concerning for ACS, especially in younger female patients
without traditional cardiovascular disease risk factors, as their risk may be significantly underestimated with commonly used ACS risk-stratifiers. Ó 2016 Elsevier Inc. All rights reserved. , Keywords—spontaneous coronary artery dissection; acute coronary syndrome
INTRODUCTION Background Spontaneous coronary artery dissection (SCAD), defined as a nontraumatic and noniatrogenic separation of the coronary artery walls in the absence of atherosclerosis, is an increasingly recognized cause of acute coronary syndrome (ACS) (1). Arterial wall dissection or vessel wall hematoma may occlude the coronary arterial lumen and lead to subsequent myocardial infarction (MI) or ischemia (2). Compared to ACS related to atherosclerotic coronary heart disease, ACS related to SCAD disproportionately affects young women without traditional cardiovascular disease (CVD) risk factors. SCAD risk factors include pregnancy and postpartum status, systemic vasculopathies such as fibromuscular dysplasia, connective tissue disorders, and recent significant physical or emotional stressors (3). Though previously thought to be quite rare, improved
RECEIVED: 18 May 2016; FINAL SUBMISSION RECEIVED: 3 August 2016; ACCEPTED: 5 September 2016 1
2
R. A. Lindor et al.
techniques for intracoronary imaging now suggest that SCAD may be the cause of up to 4% of all ACS and up to 25% of MIs in women under age 50 years (4). Despite better understanding of the prevalence and risk factors for the disease, SCAD continues to be frequently missed or misdiagnosed (4). Importance Failure to consider SCAD as a potential cause for symptoms consistent with ACS may have significant consequences. First, because SCAD often arises in individuals without traditional CVD risk factors, patients presenting with SCAD-related symptoms may be deemed by clinicians to be low risk for ACS and receive an abbreviated (or no) cardiac evaluation. Second, because the preferred treatment for stable patients is conservative medical management, failure to consider SCAD early in a patient’s course may result in patients undergoing unnecessary attempts at revascularization or receiving medical therapy mistakenly aimed at atherosclerotic disease risk factors (3). Goals of this Investigation
identified by a Boolean search of ‘‘spontaneous’’ and ‘‘coronary’’ and ‘‘dissection’’ within the diagnosis field of the EMR were identified. The results of both of these searches were limited to include only patients evaluated in the ED within 2 weeks of their diagnosis of SCAD. Patients with iatrogenic coronary artery dissection and coexistent atherosclerotic coronary artery disease were excluded, as coronary dissection in these patients represents a different disease process. Together, these search strategies identified 1684 patients, 19 of whom were included in the final study population representing a total of 20 separate SCAD episodes that were confirmed by angiography. A flow diagram showing how the study population was derived is provided in Figure 1. The majority of patients in the initial search did not have SCAD but were identified because the Boolean search tool did not consistently
1684 89 with no research consent
1595 1050 with no ED visit within 2 weeks
The goal of this investigation was to describe the initial presentation of patients with SCAD, including their symptoms, vital signs, electrocardiogram (ECG) and laboratory findings, management, and outcomes. Greater understanding of the range of presenting symptoms, risk factors, and early treatment of ACS due to SCAD may serve to increase physicians’ awareness and improve their management of patients with SCAD. MATERIALS AND METHODS
545 160 with no dissec on of any type
385 109 with SCAD in se ng of severe CAD
276 108 with SCAD in differen al but not final diagnosis
Study Design and Setting This was a retrospective chart review using the electronic medical record (EMR) to identify consecutive adult patients seen in the emergency department (ED) for SCAD-related symptoms. The study was conducted at an academic medical center with approximately 70,000 annual visits. Records from January 1, 2002, when the ED began using electronic diagnosis coding, through October 31, 2015 were included. The institutional review board approved this study.
168 73 dissec ons of structures other than coronaries
95 58 cases of iatrogenic coronary dissec on
37 17 duplicate records
Setting and Selection of Participants The EMR was searched using two different tools. First, all patients with coronary artery dissection, identified by International Classification of Diseases, Ninth Revision (ICD-9) code 414.12, were identified. Second, all patients
20 Figure 1. Selection of study participants from initial search of electronic medical record number of patient visits.
Spontaneous Coronary Artery Dissection in the ED
restrict the search terms to the diagnosis field. In addition, there is no ICD-9 code specifically for spontaneous coronary artery dissection, so the original ICD-9 search included many patients who had an iatrogenic coronary artery dissection. Methods and Measurements Utilizing widely accepted chart review methods, a standardized data collection form was developed and tested in a 5-patient pilot by two investigators (5). Ambiguously recorded data were discussed with a senior investigator (ATS), the data collection tool was revised, and two physician investigators (RAL, MST) independently abstracted data from every patient by reviewing the individual charts. For descriptive data recorded differently by the providers working with a single patient (e.g., staff physician, resident physician, nurse), all descriptors were recorded. For binary data, such as the presence of individual CVD risk factors, the data fields were marked as present if these were noted by any one of the providers caring for the patient. Binary variables that were not specifically mentioned were assumed to be absent. Overall concordance between abstractors was 87.5%, including 90% for risk factors and ECG findings and 73% for laboratory values. All discrepancies were arbitrated by a senior author.
3
two of these risk factors, 4 patients had one risk factor, and 11 patients had none. Additional data regarding patient demographics, presenting vital signs, and initial laboratory results are summarized in Table 1. Symptoms. In 85% of cases, patients presented with a chief complaint of chest pain (n = 17). Other reasons for presentation included cardiac arrest (n = 2) and vomiting (n = 1). Among patients with chest pain, the pain was most frequently described as crushing, heaviness, or pressure (n = 12, 71%), or as sharp (n = 6, 35%). Commonly associated symptoms included nausea (n = 9, 45%), diaphoresis (n = 5, 25%), lightheadedness (n = 5, 25%), and dyspnea (n = 3, 15%). In five cases (25%, 95% CI 10– 49%), patients reported having similar pain previously without seeking evaluation. In the 10 cases in which patient activity at onset was documented, the pain occurred at rest in all cases (100%, 95% CI 66–100%). Vital signs.Most patients had normal vital signs at presentation. Three patients (15%) were tachycardic and 12 patients (60%) were hypertensive. Differential diagnoses. The most common differential diagnoses documented by emergency physicians included ACS or MI (n = 16, 80%), aortic dissection (n = 9, Table 1. Patients’ Risk Factors, Presenting Vital Signs, and Laboratory Findings
Analysis The 95% confidence intervals (CI) were calculated using the score method incorporating a continuing correction (6). Statistical analyses were performed using version 9.3 of the SAS software package (SAS Institute, Cary, NC). RESULTS
Patient Characteristics CAD risk factors Obesity Hypertension Active smoker Hyperlipidemia Previous MI Known CAD
Main Results Cardiovascular disease risk factors. The documented presence of traditional CVD risk factors was assessed in all patients, including current tobacco use, obesity, prior coronary artery disease, hypertension, hyperlipidemia, previous MI, or male gender. Only 5 patients had
5 3 2 2 2 0 Median
Characteristics of the Study Subjects Of the 19 patients identified, all were female, with a mean age of 46 years (range 31–63 years). One patient had two separate episodes of SCAD. Though the search included patients diagnosed with SCAD in the 2 weeks after an ED visit, all patients in our study population were admitted to the hospital from their ED visit and diagnosed with SCAD during initial angiography at that hospitalization.
# Of Patients
Presenting vital signs HR (beats/min) RR (breaths/min) SBP (mm Hg) DBP (mm Hg) Temp ( C) SpO2 (%) Laboratory findings WBC (109/L) Hemoglobin (g/dL) Platelets (109/L) INR Initial troponin T (ng/mL) 3-hour troponin T (ng/mL 6-hour troponin T (ng/mL
% (n = 20) 25 15 10 10 0 0 Range
75 16 141 89 36.7 99
54–116 13–30 124–202 53–116 36.3–37.3 94–00
8.5 13.2 256 1.0 0.08 0.36 0.37
4.5–19.7 12.0–14.3 143–376 0.8–1 0–1.2 0–6.9 0–8.8
CAD = coronary artery disease; MI = myocardial infarction; HR = heart rate; RR = respiratory rate; SBP = systolic blood pressure; DBP = diastolic blood pressure; WBC = white blood cell; INR = international normalized ratio; SpO2 = pulse oximetry.
4
R. A. Lindor et al.
45%), pulmonary embolism (n = 9, 45%), and gastrointestinal cause such as esophageal spasm or reflux (n = 6, 30%). Laboratory findings. Troponin values drawn after a cardiac arrest or catheterization were not included in the analysis. Of the troponin values included, the initial troponin value was elevated in 13 of 18 cases at presentation (72%, 95% CI 46–89%), 16 of 17 cases at 3 h (94%, 95% CI 69–100%), and 14 of 15 cases at 6 h (93%, 95% CI 66–100%). The single patient without troponin elevation throughout the 6-h period reported that her pain had been ongoing for several weeks prior to presentation. ECG findings.The most common ECG findings at presentation, as interpreted by a cardiologist in real time, were a normal ECG (n = 7, 35%, 95% CI 16–59%) or ‘‘non-specific ST abnormality’’ (n = 6, 30%, 95% CI 13–54%), followed by ST elevation (n = 3, 15%, 95% CI 4–39%) and ST depression (n = 1, 5%, 95% CI 0–27%).
involved patients with zero or one atherosclerotic disease risk factor. Commonly used risk-stratification tools such as the HEART score or Emergency Department Assessment of Chest Pain Score, which rely heavily on the presence of atherosclerotic disease risk factors to estimate a patient’s risk of an adverse cardiac event, can inappropriately label SCAD patients as low risk (7,8). Based on these tools, a young peripartum woman with a connective tissue disorder presenting with chest pain may be calculated to be at low risk and discharged from the ED prematurely, despite demonstrating multiple risk factors for SCAD. This is of particular concern because the majority of SCAD patients in this series presented with nonspecific ECG changes, and several did not have elevations in their initial troponin levels. This highlights a limitation of these commonly used risk-assessment tools, which were designed to assess patients’ cardiac risk due to atherosclerotic disease, not all causes of ACS. Limitations
Management/outcomes. Most patients (n = 13, 65%) were admitted to the hospital after their initial ED evaluation. Four patients (20%) were sent directly to coronary angiography, and 3 patients (15%) were admitted to the ED observation unit. No patient was discharged to home. Nine patients were initiated on heparin in the ED prior to final disposition. Three patients received a cardiac stent during the index hospitalization. All patients survived > 30 days past hospital discharge. DISCUSSION Despite increased awareness of and improved diagnostic techniques for SCAD, it is an infrequently considered etiology of chest pain. Data from this single-center study demonstrate that patients with SCAD have a wide variety of presentations, ranging from mild chest pain with normal initial ECGs and troponin levels to isolated vomiting or cardiac arrest. Many patients with SCAD describe their symptoms as similar to those associated with classic angina or MI due to atherosclerotic disease. This is not unexpected, as SCAD-related symptoms at presentation are likely related to myocardial ischemia due to impaired coronary flow, just as in ACS due to underlying atherosclerosis. There are, however, important distinctions between the presentations of patients in our study population and patients with coronary atherosclerosis that may prompt ED providers to consider SCAD earlier in a patient’s course. Most prominently, patients with SCAD often have very different CVD risk-factor profiles than patients with atherosclerotic coronary artery disease. Among the 20 cases in our study cohort, the majority (75%)
This study had several limitations. First, with 20 patient encounters, the study is underpowered to draw strong conclusions regarding the typical presentation of SCAD, and therefore is best used as a qualitative description. Second, the data were collected from ED records, so data collection is dependent on the information recorded. In addition, at our institution, peripartum patients with acute labor-related issues generally present to a separate obstetrical triage area. As a result, our data may underrepresent the association between SCAD and pregnant or postpartum states, as many of these patients would have been missed by the search. In fact, no patients in our data were pregnant or recently pregnant. Finally, the restriction of the search to patients who were diagnosed within 2 weeks of an ED visit may have missed patients who presented with SCAD-related symptoms, were discharged home, and subsequently diagnosed with SCAD elsewhere or later, or not diagnosed at all. CONCLUSIONS The different risk-factor profiles between SCAD and atherosclerotic coronary artery disease suggest that providers should develop and employ a different heuristic approach for considering SCAD in patients with symptoms consistent with ACS. In patients with chest pain or other ACS symptoms but low CVD risk—especially women—providers must have a high level of suspicion for ACS due to SCAD and consider the demographics and conditions associated with SCAD. Doing so may prevent providers from underestimating patients’ cardiovascular risks and improve the recognition of SCAD.
Spontaneous Coronary Artery Dissection in the ED
REFERENCES 1. Yip A, Saw J. Spontaneous coronary artery dissection – a review. Cardiovasc Diagn Ther 2015;5:37–48. 2. Tweet MS, Hayes SN, Sridevi RP, et al. Clinical features, management, and prognosis of spontaneous coronary artery dissection. Circulation 2012;126:579–88. 3. Tweet MS, Gulati R, Hayes SN. What clinicians should know about spontaneous coronary artery dissection. Mayo Clin Proc 2015;90:1125–30. 4. Saw J, Aymong E, Mancini GB, et al. Nonatherosclerotic coronary artery disease in Young Women. Can J Cardiol 2014;30:814–9.
5 5. Kaji AH, Schriger D, Green S. Looking through the retrospectoscope: reducing bias in emergency medicine chart review studies. Ann Emerg Med 2014;64:292–8. 6. Newcombe R. Two-sided confidence intervals for the single proportion: comparison of seven methods. Stat Med 1998;17: 857. 7. Six AJ, Backus BE, Kelder JC. Chest pain in the emergency room: value of the HEART score. Neth Heart J 2008;16:191–6. 8. Than M, Flaws D, Sanders S, et al. Development and validation of the Emergency Department Assessment of Chest pain Score and 2 h accelerated diagnostic protocol. Emerg Med Australas 2014;26: 34–44.
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R. A. Lindor et al.
ARTICLE SUMMARY 1. Why is this topic important? Spontaneous coronary artery dissection (SCAD) is an under-recognized cause of acute coronary syndrome and is associated with significant morbidity and mortality. 2. What does this study attempt to show? The study attempts to describe the emergency department presentation of patients with SCAD to increase providers’ awareness of this etiology of acute coronary syndrome. 3. What are the key findings? The symptoms of SCAD are nearly indistinguishable from acute coronary syndrome caused by atherosclerotic disease, but it affects people with very different risk factors. 4. How is patient care impacted? SCAD should be considered in patients with symptoms consistent with acute coronary syndrome, even if they lack traditional atherosclerotic disease risk factors, and especially if they have one or more SCAD risk factors, including female gender, connective tissue disorder, antecedent physical or emotional stress, and pregnancy or postpartum status.
