Arrhythmic risk stratification is a challenging issue in patients with dilated cardiomyopathy (DCM), particularly when left ventricular ejection fraction (LVEF) is more than 35%. We studied the prevalence and predictors of sudden cardiac death or malignant ventricular arrhythmias (SCD/MVAs) in DCM patients categorized at low arrhythmic risk because of intermediate left ventricular dysfunction under optimal medical treatment (OMT).
DCM patients considered at low arrhythmic risk (LVEF >35% and New York Heart Association class I-III after 6 ± 3 months of OMT) were analysed. An arrhythmogenic profile was defined as the presence of at least one among a history of syncope, nonsustained ventricular tachycardia, at least 1000 premature ventricular contractions/24 h, at least 50 ventricular couplets/24 h at Holter ECG monitoring. SCD/MVAs was considered as the study end-point.
During a median follow-up of 152 months (interquartile range 100–234), 30 out of 360 (8.3%) patients at low arrhythmic risk (LVEF 47 ± 7%) experienced the study end-point [14 (3.9%) SCD and 16 (4.4%) MVA]. Compared with survivors, patients who experienced SCD/MVAs had more frequently an arrhythmogenic profile and a larger left atrium. Their LVEF at the last available evaluation before the arrhythmic event was 36 ± 12%. At multivariable analysis, left atrial end-systolic area [hazard ratio 1.107; 95% confidence interval (95% CI) 1.039–1.179, P = 0.002 for 1 mm2 increase] and arrhythmogenic profile (hazard ratio 3.667; 95% CI 1.762–7.632, P = 0.001) emerged as predictors of SCD/MVAs during follow-up.
A consistent quota of DCM patients with intermediate left ventricular dysfunction receiving OMT experienced SCD/MVA during follow-up. Left atrial dilatation and arrhythmogenic pattern were associated with a higher risk of SCD/MVA.
aCardiovascular Department, Azienda Sanitaria Universitaria Integrata di Trieste and University of Trieste
bBiostatistics Unit, Department of Medical Sciences, University of Trieste, Trieste, Italy
Correspondence to Marco Merlo, MD, Cardiovascular Department, Azienda Sanitaria Universitaria Integrata di Trieste, Via Pietro Valdoni 7, Trieste 34100, Italy E-mail: email@example.com
Received 1 December, 2018
Revised 29 January, 2019
Accepted 28 February, 2019
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