Review article: The utility of troponin and other investigations in patients presenting to the emergency department with supraventricular tachycardia

Prognostic value of cardiac troponin in elderly patients with paroxysmal supraventricular tachycardia: A multicenter study

BACKGROUND

An elevated level of cardiac troponin I (cTnI) frequently accompanies an episode of supraventricular tachycardia (SVT). However, the predictive value of cTnI in elderly SVT patients has not been examined.

METHODS

We collected the electronic medical records of elderly SVT patients (over 65 years old) who visited four Taiwanese emergency departments over a 2-year period. The patients who underwent cTnI testing were included in the cohort and further categorized based on their cTnI results (positive or negative). The study's primary outcomes were the 5-year risks of major adverse cardiovascular events (MACE) and SVT recurrence.

RESULTS

One hundred and twenty-four patients met the inclusion criteria. Of these patients, 39 (31.5%) had a positive cTnI result, and 85 (68.5%) had a negative cTnI result. Patients with a positive cTnI result were older (p = 0.029) and had a longer hospital stay (p = 0.023) than those with a negative cTnI result. Multivariate analysis showed that age > 75 years (OR = 2.41; 95% CI 1.07-5.45; p = 0.034) was an independent predictor for cTnI elevation. In the survival analysis, no difference in the incidence of five-year MACE (p = 0.656) was observed between the cTnI-positive and cTnI-negative groups. Multivariate analysis revealed that a history of coronary artery disease was the only significant independent risk factor for MACE (HR = 4.30; 95% 95% CI 1.41-13.05; p = 0.010). For SVT recurrence, the multivariate analysis revealed that previous SVT (HR = 3.37; 95% CI 1.53-7.39; p = 0.002), smoking history (HR = 2.32; 95% CI 1.03-5.24; p = 0.043), and RFA treatment (HR = 0.20; 95% CI 0.06-0.65; p = 0.008) were significant independent predictors.

CONCLUSIONS

An increased cardiac troponin level may not effectively indicate the risk of MACE in elderly SVT patients. Physicians might want to be cautious when interpreting troponin test results for this specific patient group.

A Multicenter Retrospective Evaluation of Specialized Laboratory Investigations in the Workup of Pediatric Patients With New-Onset Supraventricular Tachycardia

INTRODUCTION

Specialized laboratory evaluation of supraventricular tachycardia in children may occur, but the utility is unknown. The study objectives are to assess the type, frequency, and results of specialized laboratory testing performed in pediatric patients presenting with new-onset supraventricular tachycardia. We hypothesized that when specialized laboratory testing occurs (particularly for cardiac failure, toxicologic, inflammatory, and thyroid diseases), the results are generally within normal limits.

METHODS

This is a retrospective descriptive study using an electronic health record database (TriNetX, Inc). We collected and evaluated the following data of subjects aged younger than 18 years with a first-time supraventricular tachycardia diagnosis: demographics, diagnostic codes, deaths, and laboratory codes/results (natriuretic peptide B, natriuretic peptide B prohormone N-terminal, troponin I, toxicology testing, inflammatory markers, and thyroid studies).

RESULTS

A total of 621 subjects (524 [84.4%] without laboratory testing, 97 [15.6%] with laboratory testing) were included. Thyroid studies (65 [10.5%]) were the most frequent laboratory study performed followed by cardiovascular specific studies (35 [5.6%]), inflammatory markers (21 [3.4%]), and toxicology tests (10 [1.6%]) (P = .002). Obtained laboratory testing was more frequent with older subjects, females, and need for emergency, hospital, and critical care services.

DISCUSSION

Cardiac-specific and noncardiac laboratory testing is frequently ordered for pediatric patients who present with supraventricular tachycardia. Thyroid studies were the most common laboratory testing ordered, but abnormal results only occurred in less than a quarter of subjects. These findings may highlight a quality improvement opportunity for emergency nurses and practitioners in the practice of obtaining laboratory tests to better reflect high-value evidence-based care for this vulnerable population.

Prognostic value of cardiac troponin in dialysis patients with paroxysmal supraventricular tachycardia

A rise in cardiac troponin I (cTnI) is common in supraventricular tachycardia (SVT). While troponin elevation in SVT is thought to be a predictor of future adverse events in patients with prior coronary artery disease, the prognostic significance of cTnI in end-stage kidney disease (ESKD) patients with SVT are not known. We aimed to examine the prognostic significance of cTnI in ESKD patients presenting with SVT in the emergency department. This was a retrospective, multiple-center observational study utilizing regularly collected electronic medical records. We screened electronic medical records of all dialysis patients presenting to the emergency departments in 5 hospitals over 12 years with SVT. These patients were divided into whether cTnI was tested, and were further stratified into the cTnI-positive and cTnI-negative groups. The primary outcome of the study was the 3-year risk of major adverse cardiovascular events (MACE). Sixty-two patients were qualified for inclusion. Fifty-seven patients (91.9%) were tested for cTnI, and 5 patients were not. Patients with the cTnI test were older (P = .03) and had a longer length of hospital stay (P < .001). Forty-seven patients (82.5%) had a positive result, and 10 (17.5%) had a negative result. A history of hypertension (P = .013) and decreased left ventricular ejection fraction (P = .048) were the independent predictors of cTnI elevation. After a mean follow-up period of 20.6 ± 14.7 months, there were no differences in 3-year MACE between patients with or without elevated cTnI levels in Kaplan-Meier analysis (P = .34). A history of coronary artery disease was the only independent predictor of 3-year MACE (P = .017). Through the subgroup analysis, a history of coronary artery disease (HR 2.73; CI 1.01-7.41; P = .049) remained an independent risk factor for 3-year MACE in patients with elevated cTnI levels. A large proportion (82.5%) of troponin elevation was observed in ESKD patients with SVT, but it had a poor correlation with MACE.

Prognostic Value of Cardiac Troponin and Risk Assessment in Pediatric Supraventricular Tachycardia

Cardiac troponin I (cTnI) elevation is common in an acute episode of supraventricular tachycardia (SVT). However, there is limited evidence regarding the prognostic value of cTnI and the predictors of SVT recurrence in pediatric patients. We screened the electronic medical records of all pediatric patients presenting to the emergency departments at five Taiwanese hospitals from 1 January 2010 to 31 May 2021. Our primary outcomes were the occurrence of major adverse cardiac events (MACEs) during the follow-up period and 30-day SVT recurrence. A total of 112 patients were included in our study. Of these, 29 (25.9%) patients had positive cTnI values. Patients with cTnI elevation had significantly more complaints of dyspnea (27.6% vs. 7.2%, p = 0.008) and gastrointestinal discomfort (24.1% vs. 4.8%, p = 0.006). There were significantly more intensive care unit admissions (41.4% vs. 16.9%, p = 0.007) among the cTnI-positive group. One MACE was found in the cTnI-negative group. For 30-day SVT recurrence, the cTnI-positive group had a higher recurrence rate, without a statistically significant difference (20.7% vs. 7.2%, p = 0.075). Multivariable logistic regression analysis showed hypotension as an independent predictor of 30-day SVT recurrence (OR = 4.98; Cl 1.02-24.22; p = 0.047). Troponin had low value for predicting the outcomes of pediatric patients with SVT. The only significant predictor for recurrent SVT was initial hypotension.