Prognostic significance of oscillatory ventilation at rest in patients with advanced heart failure undergoing cardiopulmonary exercise testing

Background: Among heart failure patients diagnosed as having exertional oscillatory ventilation (OV), some present with OV at rest that persists during exercise, and others develop OV only after the onset of exercise during cardiopulmonary exercise (CPX) testing. We tested whether or not there was any difference in the prognostic significance between the two abnormal breathing patterns. Methods: Patients with New York Heart Association class III-heart failure were categorized into the following 3 groups according to their ventilation pattern during the CPX: patients with an OV pattern at rest that persisted for ≥60% of the exercise test at an amplitude of ≥15% of the average resting value (group 1), patients with the same abnormal ventilatory pattern as group 1 that was observed only during exercise (group 2), and patients without any OV (group 3). The patients were followed-up for at least 2 years to assess the composite outcome of cardiac death or hospitalization for worsening heart failure. Results: The occurrence of the composite outcome differed significantly across the groups with its highest occurrence in group 1 (21/29 [72.4%], 15/38 [39.5%] and 48/167 [28.7%]; log-rank P < 0.001). In multivariate hazard analyses, an N-terminal pro-brain natriuretic peptide of >900 pg/mL (hazard ratio [HR] = 1.72, P = 0.04), and group 1 (HR 2.03, P = 0.02) were independently associated with the composite outcome. Conclusions: Checking for the resting OV prior to incremental exercise during CPX testing may be helpful in risk-stratification among subjects with advanced heart failure.