Oxidative stress was significantly associated with peak oxygen uptake in patients with dilated cardiomyopathy. (3rd October 2022)

• Record Type: Journal Article
• Authors: Ojima, S; Kubozono, T; Kawasoe, S; Kawabata, T; Salim, A A; Ikeda, Y; Ohishi, M
• Is Part Of: European heart journal. Volume 43(2022)Supplement 2
• Publication Date: 2022-10-03
• Subjects: Cardiology -- Periodicals; Heart -- Diseases -- Periodicals; 616.12005
• DOI: 10.1093/eurheartj/ehac544.2460
• Languages: English
• ISSNs: 0195-668X

Abstract

Abstract: Background: Systemic oxidative stress is known to be associated with the severity and prognosis in patients with cardiovascular diseases (CVD), including chronic heart failure. On the other hand, exercise tolerance is closely related to the prognosis in heart failure patients. However, no report has examined how oxidative stress is involved in each parameter evaluated by cardiopulmonary exercise testing (CPET) in patients with dilated cardiomyopathy (DCM). Purpose: To examine the relationship between oxidative stress and CPET parameters such as peak VO2 and VE/VCO2 slope in patients with DCM Methods: We recruited 214 patients with CVD who were performed CPET and measured brain natriuretic peptide (BNP) and haemoglobin (Hb). Finally, we enrolled 96 patients with DCM who have dilated dimensions of the left ventricular lumen by echocardiography and are diagnosed by endomyocardial biopsy. All patients underwent CPET using 0W warm-up and 10W ramp protocol on an upright electrical bicycle ergometer. We defined low peak VO2 as peak VO2<14 ml/min/kg and high VE/VCO2 slope as VE/VCO2 slope>34. The oxidative stress level was evaluated by a d-ROMs test, in which the amount of organic hydroperoxide converted into radicals oxidizing N, N-diethyl-p-phenylenediamine hydroperoxide is measured. The high level of d-ROMs was defined as d-ROMs≥401 U.CARR. Results: Mean age was 56±15 years old. Mean ejection fraction, peak VO2 and VE/VCO2 slope were 37±15%, 16.3±5.0 ml/min/kg, and 31.0±11.8, respectively. The percentage of the high level of d-ROMs was 25%. In univariable logistic regression analysis, Hb, log BNP, and the high level of oxidative stress were significantly associated with low peak VO2, whereas, in multivariable logistic regression analysis, age, Hb, and log BNP were significant factors for high VE/VCO2 slope. In multivariable logistic regression analysis, only the high level of d-ROMs was independently associated with low peak VO2 (OR 3.18, CI 1.12–9.04, p=0.030). While, in multivariable logistic regression analysis, Hb (OR 0.51, CI 0.32–0.81, p=0.004) and log BNP (OR 2.77, CI 1.33–5.76, p=0.006) were significantly related to high VE/VCO2 slope. Conclusions: In patients with DCM, low peak VO2 was associated with the high level of d-ROMs, and high VE/VCO2 slope was associated with BNP. These results suggested that oxidative stress was only related to peak VO2. Funding Acknowledgement: Type of funding sources: None.