Noninvasive arrhythmia risk stratification in idiopathic dilated cardiomyopathy: design and first results of the Marburg Cardiomyopathy Study.
The Marburg Cardiomyopathy Study (MACAS) is a prospective, observational study designed to determine the value of the following potential noninvasive arrhythmia risk predictors in at least 200 patients with idiopathic dilated cardiomyopathy (IDC) over a 5-year follow-up period: NYHA-class, left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter, left bundle branch block and atrial fibrillation on ECG, QT/JT dispersion on 12-lead ECG, signal-averaged ECG, ventricular arrhythmias and heart rate variability (HRV) on 24-hour Holter ECG, baroreflex sensitivity, and microvolt T wave alternans during exercise. This article describes the findings among the first 159 patients with IDCs enrolled in MACAS until May 1998 (40 women, 119 men; age: 49 +/- 12 years; LVEF: 32 +/- 10%). Twenty-nine patients (18%) had atrial fibrillation and 130 patients (82%) were in sinus rhythm. Patients with sinus rhythm were further stratified according to LVEF < 30% (n = 54) versus LVEF > or = 30% (n = 76). Compared to patients with LVEF > or = 30%, patients with LVEF < 30% more often had left bundle branch block (43% vs 25%, P < 0.05), nonsustained VT (44% vs 22%, P < 0.05), decreased HRV (SDNN: 95 +/- 39 vs 128 +/- 42 ms, P < 0.01), decreased baroreflex sensitivity (5.6 +/- 4 vs 8.3 +/- 6 ms/mmHg, P < 0.01), and T wave alternans (59% vs 37%, P < 0.05). The prognostic significance of these findings will be determined by multivariate Cox analysis at the end of a 5-year follow-up. Primary endpoints in MACAS are overall mortality and arrhythmic events (i.e., sustained VT or VF, or sudden cardiac death).
Grimm
W
W
Department of Cardiology, Hospital of the Philipps-University of Marburg, Germany.
Glaveris
C
C
Hoffmann
J
J
Menz
V
V
Mey
N
N
Born
S
S
Maisch
B
B
D001145:Arrhythmias, Cardiac / Q000453:epidemiology*; D002311:Cardiomyopathy, Dilated / Q000150:complications* / Q000453:epidemiology; D016757:Death, Sudden, Cardiac / Q000517:prevention & control; D017147:Defibrillators, Implantable; D004562:Electrocardiography / Q000379:methods; D015716:Electrocardiography, Ambulatory / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012107:Research Design; D018570:Risk Assessment; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors