Non-invasive electrophysiologicalparameters and high-sensitive troponin in risk stratification of fatal events in patients with dilated cardiomyopathy

Dilated cardiomyopathy (DCM) remains a disease with a poor prognosis. The improvement of the risk stratification for the fatal events, especially sudden cardiac death (SCD) to introduce preventive measures timely is an unmet need. Previously proposed non-invasive electrophysiological predictors - heart rate turbulence (HRT) and variability (HRV), deceleration (DC), acceleration (AC) capacity and high-sensitivity troponin (hs-Tn) - have not been evaluated in DCM. Material and methods. We enrolled 54 patients with DCM and sinus rhythm aged 42 [30; 58] years (36 males) and 54 people without cardiovascular diseases (32 males, median age 47 [27; 64] years) in the control group. The follow-up period was 4 years. At baseline, we performed ambulatory (Holter) ECG monitoring (AECG) with the assessment of HRV, HRT, DC, AC, echocardiography. In 30 patients with DCM and 14 persons without cardiovascular pathology was carried out biochemical blood analysis with determination of the concentration of hs-Tn. Patients received standard treatment for CHF, 18.5 % of patients underwent implantations of cardioverter defibrillators (ICDs). Results. The median LVEF in the study group was 32 % [22; 38]. CHF signs were reported in 93 % of patients. Patients with DCM differed from the control group, significantly lower values of SDNN, pNN 50, DC, TO, TS, and higher values of AC in early morning hours and a higher concentration of high-sensitivity troponin. During the 4 years, one SCD was reported, 7 patients died due to CHF progression, and one adequate shock in a patient with ICD was detected (a total of 9 fatal events). Patients with fatal events compared to survivors had lower EF, VRS, DC, large end-diastolic volume, the class CHF, ACE in early morning hours, the number of episodes of unstable ventricular tachycardia (NHT), however, was not characterized by higher levels of hs-Tn. In univariate analysis, the following predictors significantly increased the risk of fatal events (in order of importance): LVEF (Odds Ratio (OR) 32), SDNN (OR21), DC (OR 9), AC (OR 7'), pNN50 (OR6), nVT (OR5.2; p = 0.05). In multivariate analysis, LVEF < 26 % was the only independent predictor of fatal events (sensitivity 80 %, specificity 90 %). Conclusions. Non-invasive electrophysiological predictors of AC, DC, HRV may be used as additional methods of risk stratification of fatal events in patients with dilated cardiomyopathy. The determination of the concentration of hs-Tn is inappropriate. However, the only independent predictor of adverse outcome during 4 years is the PV of the left ventricle. The decrease in EF less than 26 % increases the risk of fatal events in 32 times.

dilated cardiomyopathy, sudden cardiac death, a turbulence of heart rhythm, deceleration capacity, acceleration capacity, heart rate variability, Holter monitoring, ejection fraction, high-sensitivity troponin

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