Limitations of biomarkers serum levels during pulmonary vein isolation

Introduction and objectives

Several biomarkers have been used for evaluation and quantification of myocardial injury after effective ablation. We studied possible different thermal stability and usability of the proteins released by cardiac cells injured by different energy sources.

Methods

Firstly, we tested in vitro thermal stability of creatinine kinase (CK), myocardial bound creatinine kinase (CKMB), cardiac troponins I (cTnI) and cardiac troponins T (cTnT) in collected blood samples from 15 patients (pts) with confirmed ST-segment elevated myocardial infarction (STEMI). Secondly, the biomarkers were collected and analyzed in 82 pts treated with radiofrequency ablation (RFA) and in 79 pts treated with cryo-balloon ablation (CBA).

Results

In vitro experiment showed that all biomarkers were stable in low temperature of -30^oC. Troponins were stable in the high temperatures analyzed. A substantial drop in CK and CKMB levels were measured at 50 °C and 40° C, respectively. In vivo study showed that the increase in CKMB levels was highly significant in CBA pts only. Pathological CKMB values were observed in 24% of RFA pts and 98% of CBA pts. Pathological cTnI values were observed in all pts and the rise in cTnI levels was highly significant in both groups after ablation.

Conclusions

Both in vitro and in vivo results show that CKMB cannot be used for quantitative determination of myocardial injury produced by radiofrequency energy. Only cardiac troponins reflect myocardial injury, regardless of energy source, and may be considered in future studies for comparison of biomarkers effects of cryo versus radiofrequency ablation.Full English text available from: www.revespcardiol.org     

Clinical value of the combined use of P-wave dispersion and troponin values to predict atrial fibrillation recurrence in patients with paroxysmal atrial fibrillation

IntroductionP-wave dispersion (PWD) and cardiac troponin levels are independently associated with the recurrence of atrial fibrillation (AF) in patients with paroxysmal AF (PAF). We investigated the clinical usefulness of combining PWD and cardiac troponin I to predict AF recurrence in patients presenting to the emergency department with PAF.MethodsThis study included 65 patients with PAF who were divided into three groups according to baseline troponin I and PWD values (group 1, troponin I<0.11 ng/dl and PWD<44.5 ms; group II, troponin I<0.11 ng/dl and PWD≥44.5 ms, or troponin I≥0.11 ng/dl and PWD<44.5 ms; group III, troponin I≥0.11 ng/dl and PWD≥44.5 ms).ResultsThe AF recurrence rate was significantly higher in group III than in groups I and II. Multivariate analysis revealed that the troponin I and PWD values in group III (odds ratio: 7.236, 95% confidence interval: 1.879-27.861, p=0.004) were independent predictors of AF recurrence.ConclusionsThe combined use of PWD and basal troponin I levels is a better predictor of AF recurrence than either value alone.     

Os Escores HEART,TIMI e GRACE para Predição de Eventos Cardiovasculares Adversos Maiores no Período de 30 Dias na Era de Troponina I de Alta Sensibilidade

BackgroundMultiple scoring systems have been designed to calculate the risk of major adverse cardiovascular events (MACE) in patients with chest pain. There is no data on whether the HEART score outperforms TIMI and GRACE in the prediction of MACE, especially in the era of high-sensitivity troponin assay and in an exclusively Latin-American population.ObjectiveTo compare the performance of the HEART, TIMI, and GRACE scores for predicting major cardiovascular events at 30 days of follow-up, in patients who consult for chest pain in the emergency department.MethodsHEART, TIMI, and GRACE scores were analyzed in 519 patients with chest pain at the emergency department. The primary endpoint was the occurrence of MACE within 30 days. The performance of the HEART score was compared with the TIMI and GRACE scores using the DeLong test with p values of 0.05 considered statistically significant.ResultsA total of 224 patients (43%) had MACE at 30 days. The C statistic for the HEART, TIMI, and GRACE score was 0.937, 0.844, and 0.797 respectively (p < 0.0001). A HEART score of 3 or less had a sensitivity of 99.5% and a negative predictive value of 99% to classify low risk patients correctly; both values were higher than those obtained by the other scores.ConclusionThe HEART score more effectively predicts cardiovascular events at 30 days of follow-up compared to the other scores. High-sensitivity troponins maintain this score’s previously demonstrated superiority. This score offers more precise identification of low-risk patients. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)