Cardiovascular Events in Patients With Thyroid Storm

Zainulabedin Waqar; Sindhu Avula; Jay Shah; Syed Sohail Ali


J Endo Soc. 2021;5(6) 

In This Article

Abstract and Introduction


Context: Thyroid storm can present as a multitude of symptoms, the most significant being cardiovascular (CV). It is associated with various manifestations such as cardiac arrhythmia, heart failure, and ischemia. However, the frequencies of events and characteristics associated with patients that experience these events are not known.

Methods: Study cohort was derived from the National Inpatient Sample database from January 2012 to September 2015. Total hospitalizations of thyroid storm were identified using appropriate ICD-9 diagnostic codes. The analysis was performed using SAS.

Objective: To better understand the frequency and characteristics CV occurrences associated with thyroid storm, through a retrospective analysis of thyroid storm hospital admissions.

Design: The study cohort was derived from the National Inpatient Sample database from January 2012 to September 2015.

Setting: Total hospitalizations of thyroid storm were identified using International Classification of Diseases (ICD)-9 diagnostic codes. The analysis was performed using Statistical Analysis System (SAS).

Results: A total of 6380 adult hospitalizations were included in the final analysis, which includes 3895 hospitalizations with CV events (CEs). Most frequently associated CEs were arrhythmia (N = 3770) followed by acute heart failure (N = 555) and ischemic events (N = 150). Inpatient mortality was significantly higher in patients with CEs compared with those without CEs (3.5% vs 0.2%, P < 0.005). The median length of stay was also higher in patients with CEs compared with those without CEs (4 days vs 3 days, P < 0.0005). Atrial fibrillation was the most common arrhythmia type, followed by nonspecified tachycardia.

Conclusions: In patients who were hospitalized due to thyroid storm and associated CEs significantly increased in-hospital mortality, length of stay, and cost. Patients with obesity, alcohol abuse, chronic liver disease, and COPD were more likely to have CEs. Patients with CV complications were at higher risk for mortality. In-hospital mortality increased with ischemic events and acute heart failure. Further evaluation is needed to further classify the type of arrhythmias and associated mortality.


Thyroid storm represents an uncommon endocrine emergency.[1] Causes can vary but are generally initiated by Graves' disease, amiodarone toxicity, toxic multinodular goiter, or autoimmune thyroiditis.[1] Patient presentations for thyroid storm vary and affect multiple organ systems.[1,2] Patients can present with agitation, altered mental status, lethargy, coma, or dyspnea on exertion; they may also be seen with flushing, vitiligo, or hyperpigmentation.[1,2] Sinus tachycardia, atrial fibrillation, or a heart blockage can also be observed on telemetry.[2] Gastrointestinal symptoms can vary but commonly noted are nausea, vomiting, diarrhea, and generalized abdominal pain.[2] The diagnosis of thyroid storm is made by clinical judgment but can be quantified using Burch and Wartofsky's diagnostic parameters.[1,3,4] These parameters illustrate a culmination of multiple symptoms, which help a clinician assess when a patient may be in thyroid storm.[2,3] Burch and Wartofsky parameters have adjusted values for atrial fibrillation, heart failure, and tachycardia, which influence the parameters of thyroid storm but do not quantify the occurrence of such issues.[1,4]

One of the most disruptive clinical effects of thyroid dysfunction is its impact on the cardiovascular (CV) system and the heart, specifically.[5] Excess thyroid hormone increases the number of Beta adrenergic receptors in the myocardium and makes it more susceptible to vagal and sympathetic stimulation.[5,6] Activation of tri-iodothyronine (T3) binds to thyroid hormone nuclear receptors, activating sodium and calcium channels (in both cell membranes, as well as the sarcoplasmic reticulum), resulting in increased contractility.[7] Free T3 also stimulates the renin angiotensin-aldosterone axis, triggering systemic vascular resistance, higher diastolic blood pressure, cardiac chronotropy, and ionotropy, ultimately causing an increase in cardiac output.[3,7,8]

Thyroid storm may often cause arrhythmia in patients; however, it may also cause severe dilated cardiomyopathy, one of the leading causes of death in patients.[1,3]

In this study, we sought to define characteristics of patients admitted with thyroid storm and assess the impact of associated CV events (CEs) with their outcomes.