Red blood cell distribution width in patients undergoing transcatheter aortic valve implantation: Implications for outcomes

Is Red Cell Distribution Width a Reliable Marker for Cardiovascular Diseases? A Narrative Review

Red cell distribution width (RDW) is an easy-to-access marker which is routinely measured in complete blood count (CBC) test. Besides the classic use of RDW as a marker for discriminating different types of anemia, recent studies had indicated the relationship between high RDW and cardiovascular diseases. High RDW is not only useful in the diagnosis and prognostication of various cardiovascular conditions but also could be used as a valuable tool for predicting the incidence of cardiovascular diseases. population-based studies have indicated that higher RDW could effectively predict the incidence of heart failure (HF), atherosclerotic diseases, and atrial fibrillation (AF). It has been also demonstrated that higher RDW is associated with worse outcomes in these diseases. Recent studies have shown that high RDW is also associated with other cardiovascular conditions including cardiomyopathies, and pulmonary hypertension. The predictive role of RDW in endovascular interventions has also been demonstrated by many recent studies. Here in this review, we attempt to compile the most recent findings with older reports regarding the relation between high RDW and HF, cardiomyopathies, pulmonary hypertension, AF, atherosclerotic disorders, primary hypertension, and the outcomes of endovascular interventions. we also discussed the role of RDW in the prognostication of different cardiovascular conditions when combined with classic classification criteria.

Red blood cell distribution width (RDW) is associated with unfavorable functional outcome after transfemoral transcatheter aortic valve implantation

Background

Red blood cell distribution width (RDW) is calculated in every blood count test and reflects variability in erythrocyte size. High levels mirror dysregulated erythrocyte homeostasis and have been associated with clonal hematopoiesis as well as higher mortality in several conditions.We aimed to determine the impact of preprocedural RDW levels on functional outcomes after transcatheter aortic valve implantation (TAVI).

Methods

In this single-center retrospective study, we analyzed 176 consecutive patients receiving TAVI between 2017 and 2021. RDW upper limit of normal was < 15 %. Patients were stratified according to preprocedural RDW as having normal or elevated values. We assessed all-cause-mortality and a composite endpoint comprising cardiovascular/ valve-related mortality and cardiovascular, valve-related and heart failure hospitalization at 1 year.

Results

43 patients (24.4 %) had RDW ≥ 15 %. There were significant baseline differences between groups (Society of Thoracic Surgeons - Predicted Risk of Mortality score 3.18 %[interquartile range 1.87-5.47] vs. 6.63 %[4.12-10.54] p < 0.001; hemoglobin 13.2 g/dL[11.8-14.1] vs. 10.4 g/dL[9.8-12.2], p < 0.001, RDW-normal vs. RDW-high, respectively). Age was not distinct (80.2 years [77.5-84.1] vs 81.2[71.3-84.7], p = 0.78). 1-year-all-cause mortality was not different (7.9 % vs. 9.4 %, p = 0.79). The RDW-high group showed markedly higher NT-proBNP levels after 1 year (647 ng/ml[283-1265] vs. 1893 ng/ml[744-5109], p = 0.005), and experienced more clinical endpoints (hazard ratio 2.57[1.28-5.16] for the composite endpoint, p = 0.006). RDW remained an independent predictor of the composite endpoint when accounting for all baseline differences in multivariable regression.

Conclusion

Elevated preprocedural RDW identifies patients at risk for impaired functional outcome after TAVI and may represent a useful low-cost parameter to guide intensity of outpatient surveillance strategies.

Impact of body mass index on the outcome of elderly patients treated with transcatheter aortic valve implantation

Underweight or overweight patients with cardiovascular diseases are associated with different outcomes. However, the data on the relation between body mass index (BMI) and outcomes after transcatheter aortic valve implantation (TAVI) are not homogeneous. The aim of this study was to assess the role of low BMI on short and long-term mortality in real-world patients undergoing TAVI. We retrospectively included patients undergoing TAVI for severe aortic valve stenosis. Patients were classified into three BMI categories: underweight (< 20 kg/m²), normal weight (20-24.9 kg/m²) and overweight/obese (≥ 25 kg/m²). Our primary endpoint was long-term all-cause mortality. The secondary endpoint was 30-day all-cause mortality. A total of 794 patients were included [mean age 82.3 ± 5.3, 53% females]. After a median follow-up of 2.2 years, all-cause mortality was 18.1%. Patients in the lowest BMI group showed a higher mortality rate as compared to those with higher BMI values. At the multivariate Cox regression analysis, as compared to the normal BMI group, BMI < 20 kg/m² was associated with long-term mortality independently of baseline risk factors and postprocedural adverse events (hazard ratio [HR] 2.29, 95% confidence interval [CI] 1.30-4.03] and HR 2.61, 95% CI 1.48-4.60, respectively). The highest BMI values were found to be protective for both short- and long-term mortality as compared to lower BMI values even after applying the same adjustments. In our cohort, BMI values under 20 kg/m² were independent predictors of increased long-term mortality. Conversely, the highest BMI values were associated with lower mortality rates both at short- and long-term follow-up.

Red Cell Distribution Width and Patient Outcome in Cardiovascular Disease: A ''Real-World'' Analysis

Red cell distribution width (RDW) has been shown to predict adverse outcomes in specific scenarios. We aimed to assess the association between RDW and all-cause death and a clinically relevant composite endpoint in a population with various clinical manifestations of cardiovascular diseases. We retrospectively analyzed 700 patients (median age 72.7 years [interquartile range, IQR, 62.6–80]) admitted to the Cardiology ward between January and November 2016. Patients were divided into tertiles according to baseline RDW values. After a median follow-up of 3.78 years (IQR 3.38–4.03), 153 (21.9%) patients died and 247 (35.3%) developed a composite endpoint (all-cause death, acute coronary syndromes, transient ischemic attack/stroke, and/or thromboembolic events). With multivariate Cox regression analysis, the highest RDW tertile was independently associated with an increased risk of all-cause death (adjusted hazard ratio [HR] 2.73, 95% confidence interval [CI] 1.63–4.56) and of the composite endpoint (adjusted HR 2.23, 95% CI 1.53–3.24). RDW showed a good predictive ability for all-cause death (C-statistics: 0.741, 95% CI 0.694–0.788). In a real-world cohort of patients, we found that higher RDW values were independently associated with an increased risk of all-cause death and clinical adverse cardiovascular events thus proposing RDW as a prognostic marker in cardiovascular patients.