Poster Session II: Exercise physiology

Abstract

P244 Exercise oscillatory breathing and increased ventilation to carbon dioxide production in women with cronic heart failure and type 2 diabetes mellitus A Ascione, M Borgia, A Sciarappa, M Aversa Buon Consiglio Fatebenefratelli Hospital, Naples, Italy, Vincenzo Monaldi Hospital, Naples, Italy Topic: Exercise physiology, testing and training Background: Cardio-pulmonary exercise test with determination 02 consumption (CPET) is generally used for assessing patients with heart failure (HF). Increased slope of exercise ventilation to carbon dioxide production (VE/VCO2) is an established prognosticator in patients with heart failure. Recently, the occurrence of exercise oscillatory breathing (EOB) has emerged as an additional strong predictor even more powerful than VE/VCO2 slope. Objective: The aim of this study is to define the respective prognostic significance of these variables in female patients with type 2 diabetes mellitus. Methods:One hundred (100) womenwere recruited (mean age 54 12 years, of whom 80NYHA class II and 20 NYHA class III). As diabetics, these women were being treated with insulin and/ or oral hypoglycaemic drugs. All patients were receiving optimised therapy with beta-blockers, statins, nitro-derivatives, ACE-inhibitors and platelet anti-aggregants, and all had stable sinus rhythms. These women had been recruited in order to undergo CPETs and echocardiograms within a maximum period of 14 days. The CPETs were conducted utilising a protocol calling for testing on a cyclette with increments of 10 Watts per minute. None of them were obese. They were in stable chronic HF(average left ventricular ejection fraction, 33 þ/ 13%). We analyzed the prognostic relevance of VE/VCO2 slope, EOB, 02 pulse and peak Vo2 was evaluated bymultivariate Cox regression. Results: During a mean interval of 22 months, 22 patients died of cardiac reasons. Fifty-five percent presented with EOB. Among patients exhibiting EOB, 54% had an elevated VE/VCO2 slope and poor 02 pulse. The optimal threshold value for the VE/VCO2 slope identified by receiver operating characteristic analysis was <36.2 or >36.2 (sensitivity, 77%; specificity,64%;P<.001).Univariate predictors of death included low left ventricular ejection fraction, low peak Vo2, high VE/VCO2 slope,and EOB presence. The VE/VCO2 slope (threshold,<36.2 or>36.2) was the only other exercise test variable retained in the regression. The hazard ratio for subjects with EOB and a VE/VCO2 slope>36.2 was 14.4(95% confidence interval, 4.9-26.5; P< .001). Conclusion:These findings identify EOB as a strong survival predictor evenmore powerful than VE/VCO2 slope in diabetic women with HF.Even more in these patients EOB presence does not necessarily imply an elevated VE/VCO2 slope, but combination of either both yields to a burden of high risk.