The exclusion criteria were: acute coronary syndrome, coronary revascularisation and/or major surgery within the three months prior to enrolment, unplanned

hospitalisation due to heart failure deterioration or any other cardiovascular reason within selleck one month prior to enrolment, any condition precluding the independent performance of a walk test, and unwillingness or inability to provide written informed consent. Venous blood samples were taken in the morning following an overnight fast and after resting for at least 15 min. Standard laboratory tests, including complete blood count, serum levels of haemoglobin, creatinine, and uric acid, were performed using the standardised laboratory methods in our institution. Plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured in pg/mL using the enzyme-linked immunosorbent assay methoda, and selleck compound C-reactive protein (hsCRP) serum levels were determined by an immunonephelometric high sensitivity methodb. Renal function was assessed via the estimated glomerular filtration rate (eGFR) using the Modification in Diet in Renal Disease calculator, ie, 186 × (serum creatinine levels)–1.154 × (age)−0.203. The 6-minute walk test was performed in a long,

straight hospital corridor, over a 30-m distance. Each participant was asked to walk (not run) back and forth along the corridor as briskly as possible, so that the longest possible distance was covered in six minutes. The participant was allowed to slow down or stop and rest if necessary, particularly in the case of symptoms such as severe dyspnoea or fatigue. During any rest period, the participant was informed of the elapsed time and encouraged to recommence walking else when the symptoms attenuated enough to allow walking. However, the test was discontinued if the symptoms persisted. The participant was also allowed to discontinue the test at will at any time. Moreover, the test was interrupted by the investigator immediately one of the

following symptoms appeared: chest pain that did not resolve at rest, dyspnoea precluding continuation of walking, cramps of the lower limb muscles, balance difficulty, severe sweating, pallor, or cyanosis. Otherwise, every two minutes during the test, an investigator informed the participant of the amount of time left and encouraged him to continue the test. At six minutes, the participant was advised to stop and be seated. An investigator immediately measured post-exercise arterial blood pressure and pulse rate. The participant assessed subjective fatigue and dyspnoea levels with the modified Borg scale from 0 (none) to 10 (maximal). The distance walked was measured to the nearest whole metre.