Relationship between red blood cell distribution width and sleep-disordered breathing in patients with heart failure
E S Krasilnikova, Y Mareev, E M Seredenina, A L Kalinkin, Y U L Begrambekova, V Y Mareev, Y A A OrlovaAbstract
Background
Heart failure (HF) is often accompanied by sleep-disordered breathing (SDB). The severity of hypoxia during SDB is an independent predictor of adverse outcomes in HF patients. Red blood cell distribution width (RDW), a standard complete blood count parameter reflecting erythrocyte heterogeneity, is considered an independent marker of poor prognosis in HF patients. However, the relationship between RDW and the severity of hypoxia in HF patients remains poorly understood.
Purpose
to investigate factors influencing the increase in RDW in patients with HF and SDB.
Methods
The study included 101 patients hospitalized with worsening HF (55% men, age 72.2±9.9 years, BMI 30.5 kg/m² [26.5; 36.8], NT-pro-BNP 892.7 pg/mL [282.2; 2478.0]). Patients received guideline-recommended HF therapy: RAS inhibitors 100%, β-blockers 97%, mineralocorticoid receptor antagonists 86.1%, SGLT2 inhibitors 28.7%, diuretics 100%. Ninety percent of patients had arterial hypertension, 55% had coronary artery disease, 47% had type 2 diabetes mellitus, and 53% had atrial fibrillation. All patients underwent a standard examination, including blood sampling to determine various parameters, and echocardiography. Screening for SDB was performed using ApneaLink Plus system (SpO2, nasal flow, thorax band) after stabilization of HF. Patients were divided into two groups: RDW-CV <14.5% (n=66) and RDW-CV ≥14.5% (n=35).
Results
Patients with RDW-CV ≥14.5% were older (75.1±8.1 vs 70.7±10.4 years, p=0.029), had lower BMI (27.8 [25.5–34.7] vs 31.7 [27.9–37.9] kg/m², p=0.028), more frequently had AF (69% vs 44%, p=0.032) and higher NT-proBNP levels (2128.5 pg/ml [875.5–3470.0] vs 503.5 pg/ml [265.2–1976.5], p<0.001). SDB was detected in 64% of all included HF patients. The prevalence of SDB (64% vs 66%, p=0.999) and AHI (18.5 [9.4; 29.9] vs 24.2 [12.5; 34.2], p=0.344) did not differ between patients with normal and elevated RDW-CV. However, duration of ≤SpO290% was significantly prolonged in the RDW-CV ≥14.5% group (154 min [52–272] vs 54 min [23–141], p=0.007). Multivariable logistic regression analysis demonstrated that RDW-CV ≥14.5% was associated with increase NT-proBNP level (odds ratio [OR]: 2.14; 95% confidence interval [CI]: 1.22–3.77; p=0.008; pg/mL [ln]) and with increase ≤SpO2 90% duration (OR: 1.78; 95% CI: 1.17–2.69; p=0.004; min [ln]). Gender, age, AF and BMI did not demonstrate statistical significance in the multivariable model.
Conclusions
In our study, RDW-CV ≥14.5% in patients with HF and SBD demonstrated an independent association with duration of ≤SpO2 90% and elevated NT-proBNP levels. The interaction between HF, sleep-disordered breathing, and the degree of anisocytosis, possibly exacerbating hypoxia, warrants further attention and consideration.