Troponin Levels after Cardiac Electrophysiology Procedures: Review of the Literature

Abstract

Cardiac-specific Troponins (cTn) I and T have become markers of choice for myocardial injury. We reviewed the literature in order to understand the expected postprocedure cTn rise after electrophysiology procedures. A total of 34 studies and 1,608 patients were included. After external monophasic cardioversion, seven of 442 patients (1.6%) had minimal increase in cTnI (0.1-0.9 ng/mL), and only one of 368 (0.3%) had increase in cTnT (0.11 ng/mL). After internal cardioversion, 17 of 105 (16%) had increase in cTnI (0.7-2.4 ng/mL) but only three (2.9%) were above the cutoff for myocardial infarction (MI) (1.5 ng/mL). During implantable cardioverter-defibrillator (ICD) installation with a mean of 2-7 ICD shocks, 12 of 74 (16%) patients had cTnI >or=1.5 ng/mL (range 1.7-5.5 ng/mL) and 20 of 64 (32%) had cTnT >or=0.1 ng/mL (range 0.26-6.46 ng/mL) considered in the range of clinical MI. Radio frequency ablation (RFA) (n = 496) resulted in significant cTn elevation in 25-100% of patients with ventricular > atrial and linear > focal lesions. Average postprocedure peak cTnI ranged from 0.13 to 6 ng/mL (median: 2.36 ng/mL, max: 15 ng/mL) and cTnT 0.2 to 2.41 ng/mL (median: 0.44 ng/mL, max: 9 ng/mL). Early cTn peak at 2-8 hours was noted after RFA. External cardioversion should not cause a significant increase in cTn; RFA and ICD implantation with shocks often result in an increase in cTn. Interpretation of these markers can be difficult if acute coronary syndrome is suspected in the postprocedure period.

Evidence for Acute Myocardial and Skeletal Muscle Injury after Serial Transthoracic Shocks in Healthy Swine

“…While there is data indicating an elevation in serum troponin after transthoracic shocks, most of these studies show only small and clinically insignificant increases [1,18]. In a meta-analysis of studies after external cardioversions only 7 of 442 patients and 1 of 368 patients showed an increase in cardiac Troponin I and T, respectively [19]. Additionally, myoglobin levels and creatine kinase (CK) activity are non-specific markers for muscle injury and an increase in these markers after transthoracic shocks therefore is not reliable proof of myocardial injury and may be also attributed to skeletal muscle injury [2,4,20].…”

Biomarkers of myocardial injury with different energy sources for atrial fibrillation catheter ablation

“…A lower cTn level is expected after RF of focal area with few RF lesions. RF ablation of more myocardial tissue in the atria, such as in PV isolation, is expected to have much higher cTn levels [10][11][12][20][21][22][23][24][25]. Previous clinical studies reported contrasting data, in the setting of AF ablation, on cardiac biomarkers levels after cryoballoon ablation compared to RF ablation [7,[13][14][15][16][17][18][19]26].…”

“…First studies focused on RF lesion and it has been demonstrated that cTnI and cTnT are more sensitive and specific than CK--MB for the diagnosis of myocardial injury after RF ablation [5,6]. It has also been showed that the rise of biomarkers and the extent of myocardial damage after RF catheter ablation depend on the number of RF pulses and site of ablation [12][13][14][15][16]19]. A lower cTn level is expected after RF of focal area with few RF lesions.…”

“…As several markers have been proven to be useful for diagnosis and evaluation of size of myocardial injury after acute ischemic episode, many authors tried to implement different biomarkers to evaluate and quantify the size of effective ablation lesions [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. On one hand, previous studies have univocally shown humoral biomarkers for myocardial injury to be elevated after radiofrequency (RF) ablation, depending on the amount of energy delivered and the site of ablation [5].…”

Outcomes of non–acute coronary syndrome patients discharged from the emergency department with troponin positivity

“…An explicit chart review was undertaken to determine if patients had a history of myocardial infarction or cardiac procedure (percutaneous coronary intervention, coronary artery bypass graft, cardiac ablation, or pacemaker or implantable cardioverter-defibrillator insertion) during the previous month; these patients were excluded due to potential spurious troponin elevation. 15,20,21 At both EDs, the approach to potentially ischemic chest pain is set by protocol. Myocardial infarction is defined, in a manner consistent with the universal definition of myocardial infarction, 22 as a troponin elevation greater than the 99th percentile of the upper reference limit with a greater than 20% change between serial measurements, or troponin elevation with electrocardiographic (ECG) changes in keeping with myocardial infarction.…”