[Noninvasive Electrophysiological Predictors and Biomarkers of Malignant Arrhythmias in Patients With Ischemic Heart Disease: a 2-Year Prospective Follow-Up].

Aim: to assess prognostic value of clinical and instrumental parameters, results of noninvasive electrophysiological tests and biomarkers as predictors of malignant ventricular arrhythmias in patients with ischemic heart disease (IHD) during long-term follow-up as well as during myocardial revascularization surgery and early postoperative period.

Material: We prospectively enrolled 97 patients (mean age 61+/-10years) with angiographically confirmed coronary artery disease. Most patients (68%) had heart failure NYHA functional class II-III. Mean left ventricular ejection fraction (LVEF) was 50+/-13%; 20% of patients had LVEF less or equal 35%. Sixty two patients had revascularization procedures during follow-up.

Methods: We used 24-hour Holter monitoring and signal-averaged electrocardiography to obtain the following parameters: microvolt T-wave alternans, QT-interval duration and dynamics, heart rate turbulence (HRT) and variability. Laboratory tests included serum creatinine and creatinine clearance, brain natriuretic peptide (BNP), NT-proBNP, C-reactive protein and troponin T levels.

Results: During mean follow-up period of 25+/-11 months life-threatening ventricular arrhythmias were observed in 11 patients (11%). On univariate analysis, history of percutaneous coronary intervention (p<0.05), history of malignant arrhythmias or syncope (p<0.05), LVEF less or equal 47% (p<0.01), left atrium size more or equal 4.7cm (p<0.05), left atrium index (p=0.01), filtered QRS duration (p<0.05), abnormal heart rate turbulence (HRT) (chi-square test=6.2, p=0.01), abnormal turbulence slope (chi-square test=9.5, p<0.01), BNP more or equal 158picogram/ml (p<0.01), NT-proBNP more or equal 787 rg/ml (chi-square test=4.4, p<0.05) were significantly associated with malignant arrhythmias in long-term follow-up. History of malignant arrhythmias or syncope (OR 11.1, 95% CI 2.8-44.4; p<0.01), abnormal HRT (R 13.6, 95% CI 2.8-66.1; p<0.01), and plasma BNP more or equal 158 picogram/ml (R 14.3, 95% CI 3.2-65.0; p<0.01) were independent predictors of malignant arrhythmias on multivariate Cox regression analysis.

Conclusion: History of malignant arrhythmias, pathological HRT and plasma brain natriuretic peptide level more or equal 158 picogram/ml were independent predictors of malignant ventricular arrhythmias during 2 years follow-up of patients with ID.