Plasma Free H(2)S Levels are Elevated in Patients With Cardiovascular Disease

BACKGROUND: Hydrogen sulfide (H(2)S) has been implicated in regulating cardiovascular pathophysiology in experimental models. However, there is a paucity of information regarding the levels of H(2)S in health and cardiovascular disease. In this study we examine the levels of H(2)S in patients with cardiovascular disease as well as bioavailability of nitric oxide and inflammatory indicators. METHODS AND RESULTS: Patients over the age of 40 undergoing coronary or peripheral angiography were enrolled in the study. Ankle brachial index (ABI) measurement, measurement of plasma‐free H(2)S and total nitric oxide (NO), thrombospondin‐1 (TSP‐1), Interleukin‐6 (IL‐6), and soluble intercellular adhesion molecule‐1 (sICAM‐1) levels were performed. Patients with either coronary artery disease alone (n=66), peripheral arterial disease (PAD) alone (n=13), or any vascular disease (n=140) had higher plasma‐free H(2)S levels compared to patients without vascular disease (n=53). Plasma‐free H(2)S did not distinguish between disease in different vascular beds; however, total NO levels were significantly reduced in PAD patients and the ratio of plasma free H(2)S to NO was significantly greater in patients with PAD. Lastly, plasma IL‐6, ICAM‐1, and TSP‐1 levels did not correlate with H(2)S or NO bioavailability in either vascular disease condition. CONCLUSIONS: Findings reported in this study reveal that plasma‐free H(2)S levels are significantly elevated in vascular disease and identify a novel inverse relationship with NO bioavailability in patients with peripheral arterial disease. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01407172.