Comparison study of Olmesartan and Valsartan On myocardial metabolism In patients with Dilated cardiomyopathy (OVOID) trial

Background Myocardial metabolism plays an important role in maintaining cardiac function. Patients with dilated cardiomyopathy (DCMP) exhibit alterations in myocardial metabolism characterized by increased myocardial glucose metabolism. This study aimed to evaluate effects on myocardial metabolism of angiotensin-II receptor blockers, olmesartan and valsartan, in patients with DCMP. Methods OVOID (a comparison study of Olmesartan and Valsartan effects on myocardial metabolism in patients with Dilated cardiomyopathy), an investigator-initiated, multicenter, randomized controlled study of DCMP patients with New York Heart Association (NYHA) class II-IV, was conducted. The primary outcome was myocardial glucose metabolism measured by standardized uptake value ratio (SUVR) at 6 months after treatment. To measure SUVR, 18 F-fluoro-2-deoxyglucose (FDG) cardiac positron emission tomography (PET) was performed at baseline and six months after receiving the study agent. A total of 44 patients were randomized at a 1:1 ratio to receive olmesartan (at a dose of 20 mg once daily) or valsartan (at a dose of 160 mg twice daily) for 6 months, in addition to a recommended therapy. Results Baseline clinical characteristics and SUVR measured by 18 F-FDG PET data did not differ significantly between olmesartan and valsartan groups. The average left ventricular ejection fraction (LVEF) of patients was 25.1±7.8. Among patients with DCMP who received olmesartan or valsartan for 6 months, LVEF significantly increased. However, it was not significantly different between the two groups. Six-month follow-up 18 F-FDG PET showed that SUVR value was significantly lower in the olmesartan group than that in the valsartan (3.76 ± 2.12 versus 7.33 ± 4.08, P = 0.01). Conclusions Six months of olmesartan therapy significantly decreased myocardial glucose metabolism in DCMP patients compared to valsartan therapy for six months. Trial registration ClinicalTrials.gov ; NCT04174456 ; 18 November 2019 Clinical Perspective What is New? In patients with dilated cardiomyopathy (DCMP), six months of olmesartan therapy significantly decreased myocardial glucose metabolism in DCMP patients compared to valsartan therapy for six months. Olmesartan is as effective as valsartan in treating heart failure (HF) and improving left ventricular ejection fraction and symptoms in DCMP. What Are the Clinical Implications? Myocardial metabolism plays an important role in maintaining cardiac function. Impairment of myocardial metabolism can contribute to progression of left ventricular remodeling and contractile dysfunction in HF. Results of the present study revealed different effects on myocardial glucose metabolism between angiotensin II receptor blockers (ARBs) in DCMP. In addition to its inhibitory effects on renin-angiotensin-aldosterone systems in HF, olmesartan as an ARB might be considered when considering its effects on myocardial glucose metabolism. These findings provide further insights into mechanisms responsible for the beneficial effect of ARB on myocardial metabolism. They could redirect future translational investigations in an effort to identify novel therapeutic targets for myocardial recovery in patients with DCMP.