Relationship of resting hemoglobin concentration to peak oxygen uptake in heart failure patients

Abstract

Anemia is frequent in chronic heart failure (HF). To calculate what change in peak oxygen uptake ( _ VO 2 ) should be expected in the event of changes in hemoglobin concentration, we studied the correlation between peak _ VO 2 and hemoglobin concentration in a large HF population. We carried out retrospective analysis of all cardiopulmonary exercise tests (CPET) performed in our HF Clinic between June 2001 and March 2009 in HF patients who had a resting hemoglobin concentration measurement taken within 7 days of the CPET. We collected 967 CPETs, 704 tests were considered maximal and analyzed. We identified 181 patients (26%) as anemic. Peak _ VO 2 was lower (P < 0.001) in anemic patients (971 ± 23 ml/min) compared with nonanemic (1243 ± 18 ml/min). The slope of the _ VO 2 vs. hemoglobin ratio was 109 ml/min/g/dl at peak exercise. This correlation remained significant also when several confounding variables were analyzed by multivariate analysis. As an average, each gram of hemoglobin accounts, at peak exercise, for 109 ml/min change in _ VO 2 which is equivalent to 0.97 ml/min/kg. Therefore, in HF patients anemia treatment should increase _ VO 2 by 109 ml/min for each g/dl of hemoglobin increase. Am. J. Hematol. 85:414-417, 2010. V

Abnormal blood lactate accumulation during repeated exercise testing in myalgic encephalomyelitis/chronic fatigue syndrome

“…Furthermore, the decrease in resting hemoglobin concentration of 0.7 g/dL in both study groups from CPET 1 to CPET 2 should be taken into consideration. As an average, a reduction in hemoglobin concentration of 1 g/dL accounts for a reduction in peak VO 2 of 0.97 mL/kg/min (Agostoni et al 2010). In our study, this would equal an expected mean reduction in peak VO 2 of 0.68 mL/kg/min from CPET 1 to CPET 2 .…”

“…As an average, a reduction in hemoglobin concentration of 1 g/dL accounts for a reduction in peak VO 2 of 0.97 mL/kg/min (Agostoni et al. ). In our study, this would equal an expected mean reduction in peak VO 2 of 0.68 mL/kg/min from CPET 1 to CPET 2 .…”

Exercise Performance of Chronic Heart Failure Patients in the Early Period of Support by an Axial‐Flow Left Ventricular Assist Device as Destination Therapy

“…At the time of the CPET, LVAD patients presented a moderate degree of anemia, with Hb levels significantly lower than those recorded in the reference patients. When the peak VO 2 reached by the patients was adjusted for Hb level , the peak oxygen uptake was found to be slightly but not significantly greater in LVAD patients than in reference patients.…”

“…The usual ergospirometric parameters were analyzed . Oxygen uptake at peak of exercise (peak VO 2 ) was calculated as the average over a 10‐s period and was expressed relative to body weight (mL/kg/min); in the analysis of the results, peak VO 2 was evaluated both using the recorded values and after adjustment to a uniform Hb level of 15 g/dL . Peak exercise capacity was expressed in watts as maximum sustained workload (W max ).…”

Cardiovascular mortality and chronotropic incompetence in systolic heart failure: the importance of a reappraisal of current cut‐off criteria

“…A reduced peak oxygen uptake (pVO 2 ) during a maximal cardiopulmonary exercise test (CPET) has been extensively shown to be closely related to a poor outcome in patients with heart failure (HF) . Indeed, VO 2 represents a composite index, being dependent on cardiac function, stroke volume, and heart rate (HR), as well as on O 2 transport and its extraction by the peripheral muscles . However, among all these factors, the actual role of exercise‐induced HR response, and specifically of the so‐called chronotropic incompetence (CI), is still debated .…”