Prognostic value of cardiac troponin levels in patients presenting with supraventricular tachycardias

Clinical Interpretation of Serum Troponin in the Era of High-Sensitivity Testing

Cardiac troponin (Tn) plays a central role in the evaluation of patients with angina presenting with acute coronary syndrome. The advent of high-sensitivity assays has improved the analytic sensitivity and precision of serum Tn measurement, but this advancement has come at the cost of poorer specificity. The role of clinical judgment is of heightened importance because, more so than ever, the interpretation of serum Tn elevation hinges on the careful integration of findings from electrocardiographic, echocardiographic, physical exam, interview, and other imaging and laboratory data to formulate a weighted differential diagnosis. A thorough understanding of the epidemiology, mechanisms, and prognostic implications of Tn elevations in each cardiac and non-cardiac etiology allows the clinician to better distinguish between presentations of myocardial ischemia and myocardial injury-an important discernment to make, as the treatment of acute coronary syndrome is vastly different from the workup and management of myocardial injury and should be directed at the underlying cause.

Evaluation of troponin I serum levels in patients with arrhythmias with and without coronary artery disease

BACKGROUND

Elevated levels of cardiac enzymes in the blood are an indicator of ongoing cardiac ischemia. Persistent tachycardia may lead to myocardial ischemia due to oxygen supply-demand mismatch.

OBJECTIVES

We sought to evaluate the probability of underlying coronary artery disease (CAD) in patients with symptomatic supraventricular (SVT) or ventricular tachyarrhythmias (VT) based on cardiac enzyme level fluctuation.

MATERIALS AND METHODS

Troponin I (TNI) levels were measured twice and coronary angiography was also performed in patients without a history of cardiovascular disease and symptomatic SVT or VT.

RESULTS

Of the 114 (group A: CAD (n = 40), group B: no CAD (n = 74)) patients eligible for the study, 34 patients in group A and 64 patients in group B had SVT, while 6 patients in group A and 10 patients in group B had VT. All patients with underlying CAD developed a significantly elevated TNI level compared to baseline, irrespective of arrhythmia type (2.02 ± 7.98 ng/ml vs. 5.64 ± 13.38, p = 0.031). In patients without CAD, TNI level was not significantly elevated compared to the baseline level, irrespective of arrhythmia type (0.34 ± 1.38 ng/ml vs. 0.48 ± 1.48 ng/ml, p = 0.158). Most patients with normal TNI levels (46 of 47 patients; 98 %) had SVT. CAD was present in 13 of 47 patients (27 %) with tachycardia, despite normal TNI levels.

CONCLUSIONS

Elevated TNI levels are not helpful to discriminate between SVT and VT. An increase in TNI level in repeated blood sampling can help identify patients with higher probability of underlying CAD. Patients with VT demonstrated higher increases in TNI levels, compared to patients with SVT.

Cardiac Troponin I but Not N-Terminal Pro-B-Type Natriuretic Peptide Predicts Outcomes in Cardiogenic Shock

This study investigates the prognostic value of cardiac troponin I (cTNI) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in patients with cardiogenic shock (CS). Data regarding the prognostic value of cardiac biomarkers in CS is scarce, furthermore, most studies were restricted to CS patients with acute myocardial infarction (AMI). Therefore, consecutive patients with CS from 2019 to 2021 were included. Blood samples were retrieved from day of disease onset (day 1) and on days 2, 3 and 4 thereafter. The prognostic value of cTNI and NT-proBNP levels was tested for 30-day all-cause mortality. Statistical analyses included univariable t-tests, Spearman's correlations, Kaplan-Meier analyses and multivariable Cox proportional regression analyses. A total of 217 CS patients were included with an overall rate of all-cause mortality of 56% at 30 days. CTNI was able to discriminate 30-day non-survivors (area under the curve (AUC) = 0.669; p = 0.001), whereas NT-proBNP (AUC = 0.585; p = 0.152) was not. The risk of 30-day all-cause mortality was higher in patients with cTNI levels above the median (70% vs. 43%; log rank p = 0.001; HR = 2.175; 95% CI 1.510-3.132; p = 0.001), which was observed both in patients with (71% vs. 49%; log rank p = 0.012) and without AMI-related CS (69% vs. 40%; log rank p = 0.005). The prognostic impact of cTNI was confirmed after multivariable adjustment (HR = 1.915; 95% CI 1.298-2.824; p = 0.001). In conclusion, cTNI-but not NT-proBNP-levels discriminated 30-day all-cause mortality in CS patients.

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.

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.

The Prognostic Value of Cardiac Troponin I in Patients with or without Three-Vessel Disease Undergoing Complete Percutaneous Coronary Intervention

Postprocedural cardiac troponin I (cTnI) elevation commonly occurs in patients undergoing percutaneous coronary intervention (PCI); however, its prognostic value remains controversial. This study aimed to investigate the prognostic value of peak postprocedural cTnI in cardiac patients with or without three-vessel disease (TVD) undergoing complete PCI. A total of 1237 consecutive patients (77% males, mean age 58 ± 10 years) with normal baseline cTnI levels were enrolled, 439 patients (77% males, 59 ± 10 years) with TVD, and 798 patients (77% males, 57 ± 10 years) with single- or double-vessel disease (non-TVD). The primary outcome was the occurrence of major adverse cardiovascular events (MACE), defined as a composite of non-fatal MI, non-fatal stroke, unplanned revascularization, re-hospitalization due to heart failure or severe arrhythmias, and all-cause death. During the median follow-up of 5.3 years, a total of 169 patients (13.7%) developed MACE, including 73 (16.6%) in the TVD group and 96 (12.0%) in the non-TVD group (p = 0.024). After adjustment, the multivariate Cox analysis showed that hypertension (HR 1.50; 95% CI: 1.01–2.20; p = 0.042), TVD (HR 1.44; 95% CI: 1.03–2.02; p = 0.033), and cTnI ≥ 70× URL (HR 2.47; 95% CI: 1.28–4.78, p = 0.007) were independently associated with increased MACE during long-term follow-up. Further subgroup analyses showed that cTnI ≥ 70× URL was an independent predictor of MACE in TVD patients (HR 3.32, 95% CI: 1.51–7.34, p = 0.003), but not in non-TVD patients (HR 1.01, 95%CI: 0.24–4.32, p = 0.991). In conclusion, elevation of post-PCI cTnI ≥ 70× URL is independently associated with a high risk of MACE during long-term follow-up in patients with TVD, but not in those with non-TVD.

Prognostic Value of Cardiac Troponin I in Patients with Ventricular Tachyarrhythmias

Besides the diagnostic role in acute myocardial infarction, cardiac troponin I levels (cTNI) may be increased in various other clinical conditions, including heart failure, valvular heart disease and sepsis. However, limited data are available regarding the prognostic role of cTNI in the setting of ventricular tachyarrhythmias. Therefore, the present study sought to assess the prognostic impact of cTNI in patients with ventricular tachyarrhythmias (i.e., ventricular tachycardia (VT) and fibrillation (VF)) on admission. A large retrospective registry was used, including all consecutive patients presenting with ventricular tachyarrhythmias from 2002 to 2015. The prognostic impact of elevated cTNI levels was investigated for 30-day all-cause mortality (i.e., primary endpoint) using Kaplan–Meier, receiver operating characteristic (ROC), multivariable Cox regression analyses and propensity score matching. From a total of 1104 patients with ventricular tachyarrhythmias and available cTNI levels on admission, 46% were admitted with VT and 54% with VF. At 30 days, high cTNI was associated with the primary endpoint (40% vs. 22%; log rank p = 0.001; HR = 2.004; 95% CI 1.603–2.505; p = 0.001), which was still evident after multivariable adjustment and propensity score matching (30% vs. 18%; log rank p = 0.003; HR = 1.729; 95% CI 1.184–2.525; p = 0.005). Significant discrimination of the primary endpoint was especially evident in VT patients (area under the curve (AUC) 0.734; 95% CI 0.645–0.823; p = 0.001). In contrast, secondary endpoints, including all-cause mortality at 30 months and a composite arrhythmic endpoint, were not affected by cTNI levels. The risk of cardiac rehospitalization was lower in patients with high cTNI, which was no longer observed after propensity score matching. In conclusion, high cTNI levels were associated with increased risk of all-cause mortality at 30 days in patients presenting with ventricular tachyarrhythmias.

Features of the Metabolisms of Cardiac Troponin Molecules—Part 1: The Main Stages of Metabolism, Release Stage

Cardiac troponins (cTns) have long been the most valuable and specific biomarkers for detecting ischemic myocardial cells (MCs) injury, which is one of the key signs of myocardial infarction (MI). Modern methods (highly sensitive and ultra-sensitive immunoassays (hs-cTns)) of detection are an important and indispensable tool for the early diagnosis of MI and the choice of patient management protocols. Timely diagnosis of MI can significantly improve the prognosis of patients. However, in real clinical practice, doctors often face a significant problem when using cTns—the difficulty of differential diagnosis due to frequent and unexplained increases in the concentration of cTns in blood serum. In addition, there is conflicting information that may potentially affect the diagnostic capabilities and value of cTns: the influence of certain biological factors (diurnal rhythm, gender and age) on serum cTns levels; extra-cardiac expression of cTns; the possibilities of non-invasive diagnosis of MI; and other pathological conditions that cause non-ischemic injury to MCs. To solve these problems, it is necessary to concentrate on studying the metabolism of cTns. The review of our current knowledge about cTns metabolism consists of two parts. In this (first) part of the manuscript, the main stages of cTns metabolism are briefly described and the mechanisms of cTns release from MCs are considered in detail.

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.