Exercise oscillatory ventilation as a predictor of mortality in patients with amyloid cardiomyopathy

Abstract

Abstract Background Exercise oscillatory ventilation (EOV) signals multiple abnormalities in hemodynamics and ventilatory control which may predict poor outcome in patients with cardiac diseases. Purpose To assess whether EOV (+) patients with amyloid cardiomyopathy show higher mortality rates compared to their counterparts without EOV. Methods We analyzed cardiopulmonary exercise testing results for EOV defined by continuous (>60% of exercise duration) oscillations in minute ventilation (VE), cycling with a frequency of one minute and an amplitude above 15% of resting VE, in patients with amyloid cardiomyopathy. Results 156 patients with amyloid cardiomyopathy, aged 78 (±7) years, 87% male with a NYHA functional class of II (49.4%) and median B-type natriuretic peptide levels of 2548 (1374-4703) ng/L. Comorbidities include hypertension (73.1%), polyneuropathy (45.5%), coronary heart disease (41.0%), diabetes mellitus (17.3%) and chronic obstructive pulmonary disease (10.9%). Patients had a mean peak oxygen consumption of 14.8 (±4.42) ml/kg·min and a VE to carbon dioxide production (VCO2) slope ≥ 40 in 67.9% of cases. EOV was seen in 38 (24.4%), clearly absent in 92 (59.0%) and not clearly differentiable in 26 (16.7%) patients. 33 (21.2%) had a HF-related hospitalization and 31 (19.9%) died. EOV shows a hazard ratio of 2.35 (CI 1.088 – 5.075, p-value <0.05) for all-cause mortality. In fact, the log-rank test showed a difference in survival time between patients with and without EOV (p=0.03) with a median survival time of 46 months. Conclusion EOV may improve the prognostic yield of incremental CPET in patients with amyloid cardiomyopathy.Kaplan-Meier Curve for EOV