Stellenwert der kardialen Enzyme bei Patienten mit Koronarsyndrom und bestehendem Vorhofflimmern

Abstract

Herz- Kreislauf- Erkrankungen, wozu u.a. Vorhofflimmern (VHF) gezählt wird, besitzen aufgrund einer hohen und in Zukunft weiter zunehmenden Prävalenz eine große gesellschaftliche Bedeutung. Bei dem Verdacht eines Myokardinfarktes (MI) ist eine schnelle, sichere Diagnosestellung und Differenzierung zwischen einem MI Typ1 und Typ2 nötig, da es entscheidend für die Prognose und Outcome dieser Patienten ist. Vergangene Studien konnten eine hohe Herzspezifität und Empfindlichkeit des Biomarkers hochsensitives Troponin T (hs-TNT) für die Diagnostik eines akuten Koronarsyndroms (ACS) aufzeigen. Diese Arbeit analysiert den Zusammenhang und die Aussagekraft des Markers hs- TNT bei Patienten mit einem Nicht-ST-Hebungsinfarkt (NSTEMI) und VHF.

Atrial fibrillation (AF) is the most common sustained arrhythmia in adults and is associated with an increased risk of death. A highly sensitive and specific differentiation of myocardial infarction (MI) type1 and type2 is decisive for developing an individual therapeutic strategy and the prognosis of these patients. Studies have shown that high-sensitiv Troponin T (hs-TNT) can be highly specific for myocardial damage and for the diagnosis of acute coronary syndrome (ACS). We investigated hs-TNT utility in patients with non-ST-segment elevation myocardial infarct (NSTEMI) and AF in the acute setting. Methods We studied 2904 consecutive patients undergoing coronary angiography during 2013/14 in the Medical Department, Division of Cardiology Campus Virchow-Klinikum. From patients with the primary diagnosis of AF and clinical symptoms suggestive of myocardial ischemia the cardiac biomarkers hs-TNT, cardiac troponin T (cTNT) and creatine kinase (CK) were obtained on presentation in the emergency department. For a subset of patients additional measurment was made after 3-6 hours. For a differential diagnosis between MI type1 and type2 coronary angiography was performed, controlling for hemodynamically relevant stenosis. These coronary angiography results were evaluated and examined for correlations with patient data. Results In the studied sample 106 patients had NSTEMI, showed AF and elevated troponin levels on presentation. Mean patients age was 75 (±9,32) and 74% were men. 99% of the patients had a history of coronary artery disease, 45% had prior paroxysmal AF. Troponin showed higher levels in patient with a significant coronary heart disease (78%) in comparison to those without a significant coronary heart disease (22%), (hs-TNT(<50ng/l) 542,31 vs. 321,80, cTNT(<30ng/l) 373,47 vs.125,87). Although this difference did not reach statistical significance. Patients without a significant stenosis showed a higher heart rate compared to those who had benefit from coronary angiography intervention (106/min vs. 86/min, p=0,002*). Conclusion Heart rate is often associated with elevated Troponin levels but the pathomechanism is not sufficiently clarified. These data shows that AF in the acute setting is frequetly associated with elevated hs-TNT. In one fourth of the patients, the stenosis of a major coronary artery was not the cause of the elevation, hence the coronary angiography brought no benefit for the patient. Troponin levels did not differ significantly between patients with distinct coronary heart disease and ACS. While a clear trend was visible, low case numbers made a show of significance difficult. Furthermore none of the collected biomarkers and metadata was sufficient to predict MI type1 and type2.