The Association between Peripheral Blood Cells and the Frailty Syndrome in Patients with Cardiovascular Diseases

BACKGROUND: Frailty syndrome is characterized by multisystem dysregulation frequently found in older individuals or even in younger patients with chronic disabling diseases such as cardiovascular diseases. OBJECTIVE: To determine whether peripheral blood cell count, and its subpopulations, red blood cell and platelets, morphology and different ratios (neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and red blood distribution width-to-platelet ratio) are associated with cardiac frail patients, and through this to improve the prediction of frailty status in patients with cardiovascular diseases. METHODS: An observational, retrospective, cohort study enrolling 179 patients with cardiovascular disease divided into two groups: non-frail group (100 pts) and frail group (79 pts), a cohort detached from the Frail.RO study. The frailty was evaluated based on the Fried criteria; haematological markers, sociodemographic data, and variables related to cardiovascular diseases and comorbidities were also recorded. RESULTS: Lower lymphocytes, platelet count, and neutrophil-to-lymphocyte ratio were significantly associated with a more severe frailty syndrome. Regarding red blood cells, haemoglobin concentration and red cell distribution width significantly correlated with the severity of the frailty syndrome. Receiver operating characteristic curve analysis for these markers associated with the frailty syndrome revealed an acceptable sensitivity of 66% and specificity of 65% to identify frail individuals. Malnutrition and hypercholesterolemia are relevant predictors for identifying frailty in hospitalized cardiovascular patients. CONCLUSION: The evaluation of peripheral blood cell composition routinely measured in clinical practice can represent a valuable, but limited indicator, to diagnose frailty syndrome and eventually, the effects of interventions in frail patients with cardiovascular diseases.