Pimentel M, Zimerman A, Chemello D, Giaretta V, Andrades
M, Silvello D, Zimerman L, Rohde LE

J Interv Card Electrophysiol. 2017 Mar;48(2):131-139.

PURPOSE: Risk stratification of serious arrhythmic events in patients with
nonischemic heart failure (HF), beyond estimates of left ventricular ejection
fraction (LVEF), remains an important clinical challenge. This study aims to
determine the clinical value of different noninvasive and invasive tests as
predictors of serious arrhythmic events in patients with nonischemic HF.

METHODS: A prospective observational study was conducted including 106
nonischemic HF patients who underwent a comprehensive clinical and laboratory
evaluation including two-dimensional echocardiography, 24-h Holter monitoring,
cardiopulmonary exercise testing (CPX), and an invasive electrophysiological
study. The study’s primary end-point was either syncope, appropriate therapy by
implantable cardioverter-defibrillators, or sudden cardiac death.

RESULTS: During a mean follow-up of 704 ± 320 days, the primary end-point
occurred in 15 patients (14.2%). In multivariable analysis, LV end-diastolic
diameter >73 mm (hazard ratio [HR] 3.7; p = 0.016), exercise periodic breathing
(EPB) on CPX (HR 2.88; p = 0.045), and non-sustained ventricular tachycardia
(NSVT) ≥10 beats (HR 8.2; p < 0.01) remained independently associated with
serious arrhythmic events. The positive predictive value of the presence of two
of these predictors ranged from 44 to 100%. The absence of all three factors
(n = 65, 61% of the sample) identified a subset of patients with low risk of
future arrhythmic events, with a negative predictive value of 96.9%.

CONCLUSIONS: In this cohort study of nonischemic HF patients, LV dimension, EPB,
and NSVT ≥10 beats were independent predictors of serious arrhythmic events. The
presence or absence of these characteristics identified sub-groups of high and
low risk of serious arrhythmic events, respectively.