When older adults experience acute coronary syndrome (ACS), they often present with what are considered “atypical” symptoms. Because their symptoms less often match the expected presentation of ACS, older patients can have delayed time to assessment, to performance of an electrocardiogram, to diagnosis, and to definitive management. Unfortunately, it is this very group of patients who are at the highest risk for having ACS and for complications from ACS. This article aims to outline presentation, outcomes, and potential solutions of underrecognition of ACS in the older adult population.
Key points
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Consider acute coronary syndrome (ACS) in older patients who present with dyspnea, diaphoresis, syncope, nausea, vomiting, altered mental status, fatigue, or generalized weakness even if they do not have any chest pain.
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Have a low threshold to obtain an electrocardiogram and troponin level in elderly patients with symptoms of possible ACS even without chest pain.
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Once ACS is identified, treat patients with atypical symptoms just as aggressively as you would patients with active chest pain.
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Older adults with a high-risk non–ST-segment elevation myocardial infarction are more likely to have atypical symptoms than younger patients but may benefit more from early invasive therapy.
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Reframe the dichotomy of “typical” and “atypical” symptoms and, instead, consider the continuum and range of symptoms with which patients may present when having ACS.
Rapid fire: identification of acute coronary syndrome in the older adult
Case
A 77-year-old woman presented to the emergency department (ED) with a chief complaint of “allergic reaction.” She had a past medical history of hypercholesterolemia and psoriatic arthritis. Per emergency medicine services (EMS) personnel, she had been sitting outside when she suddenly developed diaphoresis, nausea, and shortness of breath. She thought she had seen some ants around but denies any known bites. She denied urticaria or any skin itchiness. She was given intramuscular epinephrine and intravenous diphenhydramine and methylprednisolone by EMS and stated her nausea had improved.
At the time of evaluation, the patient reported that she was feeling well. She was in no acute distress and had a normal cardiopulmonary examination. She was placed on a cardiac monitor and monitored for four hours. As the physician was preparing the discharge instructions, as an afterthought, they ordered an electrocardiogram (ECG), which showed a normal sinus rhythm with inverted T waves in leads V1-V3. Laboratory tests were ordered. The physician was not sure if the T-wave inversions were new or old but wondered if the patient did have an anaphylactic response or if there was something else going on.
Introduction
The Problem
When older adults (aged 65 and over) experience acute coronary syndrome (ACS), they often present with what are considered “atypical” symptoms. Because their symptoms less often match the expected presentation of ACS, older patients can have delayed times to assessment, performance of an ECG, diagnosis, and definitive management. Unfortunately, studies in multiple different countries have shown that this group of patients is at the highest risk for having ACS and for complications from ACS.
Definitions of Acute Coronary Syndrome
ACS includes a spectrum of presentations from unstable angina to non–ST-segment elevation myocardial infarction (NSTEMI) and ST-segment elevation myocardial infarction (STEMI) that occur when there is a mismatch between myocardial oxygen supply and demand.
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Unstable angina is defined as worsening symptoms (usually chest pain) with exertion, that are relieved by rest with no elevation of biomarkers.
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An NSTEMI occurs when there is evidence of subendocardial injury based on an elevated biomarker level without ECG findings of a transmural infarct.
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An STEMI occurs when there is transmural ischemia, as evidenced by ST-segment elevation on the ECG.
Epidemiology of Acute Coronary Syndrome
In the United States, the demographics of patients who are diagnosed with ACS are as follows:
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Average age of individuals diagnosed with ACS is 68 years.
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ACS is diagnosed in men and woman in a 3:2 ratio.
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The annual incidence of ACS in the United States is 780,000, of which 70% is due to NSTEMIs.
Acute Coronary Syndrome Risk with Age
Age is a significant risk factor for ACS and an independent predictor of higher mortality. It is estimated that 60% to 65% of STEMIs occur in patients aged 65 years or older, and 28% to 33% occur in patients aged 75 years or older. In addition, as many as 80% of all deaths related to myocardial infarction (MI) occur in persons 65 years and older.
Older patients who present with NSTEMI and STEMI are less likely to present with “typical” chest pain symptoms. Sometimes, symptoms other than chest pain that can be present in a patient with ACS are termed “anginal-equivalent” symptoms. It is important to understand the range of ways in which ACS can present in the older population in order to diagnose and treat them more quickly and effectively.
Presentation and diagnosis
To diagnose ACS, clinicians must obtain a thorough history, ECG, and cardiac biomarkers, such as troponin level. Current guidelines recommend an ECG be performed within ten minutes of arrival to identify STEMI among patients presenting to the ED with chest pain. However, many older adults who are ultimately found to have ACS do not present with chest pain as their primary concern, and so their ECG is often delayed. , ,
In a review of more than 430,000 patients with confirmed acute MI, one-third had no chest pain on presentation to the hospital, and those without chest pain were more often older, female, or diabetic. , Even in patients who are having an STEMI, the proportion of patients without chest pain increases significantly with age. Chest pain is present in more than 90% of patients having an STEMI who are under age 65, but in only 57% of patients over age 85 ( Fig. 1 ). Given this, traditional triage protocols may miss geriatric patients with ACS.
Pathophysiology of “atypical” symptoms
There are many potential reasons for the lack of chest pain in older adults presenting with ACS. This population may have higher levels of endogenous opioids or increased opioid sensitivity that could blunt the sensation of chest pain. In addition, they may have impaired peripheral or central pain sensation or neuropathy because of age-related changes or diabetes. Older patients may also have ischemic preconditioning, in which they have had many prior episodes of mild ischemia, which has desensitized them to the chest pain. Older patients also have a higher prevalence of multivessel disease and may have developed collateral flow. In addition, older patients may be more likely to experience dyspnea because of underlying lung disease and reduced pulmonary reserve.
Common presentations of acute coronary syndrome in older adults
Older adults who have confirmed ACS can present with a range of symptoms. Chest pain remains the most common chief complaint in patients with ACS. However, ACS can present with a range of other symptoms and without chest pain. Among patients with ACS without a chief complaint of chest pain, the most common presenting symptom is dyspnea, present in about 50%, followed by diaphoresis (26%), nausea/vomiting (24%), and syncope (19%) ( Fig. 2 ). Other possible symptoms include changes in mental status, “indigestion,” and generalized weakness or fatigue. It is important to identify these symptoms as potential manifestations of ACS, as patients with these symptoms experience a delay in diagnosis and definitive management, and higher morbidity and mortality.
