Anemia is a common comorbidity in patients with chronic heart failure (CHF) and is associated with worse clinical outcomes, including increased hospitalization, reduced exercise tolerance, diminished quality of life, and higher mortality (1). The prevalence of anemia among heart failure patients varies widely, ranging from 20% to over 50%, depending on the population studied and the diagnostic criteria used (2, 3). Several pathophysiological mechanisms contribute to anemia in CHF, such as hemodilution, iron deficiency, chronic inflammation, impaired renal function, and the use of certain medications like angiotensin-converting enzyme inhibitors (4).

Although global data highlight the significant impact of anemia in CHF, there is limited institution-specific data from the Indian subcontinent, particularly from South India, where both anemia and cardiovascular diseases are prevalent due to nutritional, socioeconomic, and healthcare disparities. Previous studies have reported variable anemia prevalence in Indian heart failure populations, with some suggesting figures close to 40% or higher (5). However, these findings are not uniform, and local demographics, dietary patterns, and comorbid conditions may influence the prevalence and profile of anemia in such patients.

Despite advancements in the management of CHF, anemia remains underdiagnosed and undertreated. The clinical relevance of routinely screening and managing anemia in CHF is underscored by evidence linking hemoglobin correction to improved outcomes (6). However, therapeutic strategies remain inconsistent, and optimal management protocols for CHF-related anemia in the Indian context are lacking.

There exists a research gap regarding institutional-level data on anemia prevalence among heart failure patients, especially in tertiary care teaching hospitals. Most of the earlier Indian studies were either multicentric with wide variability or lacked detailed stratification by New York Heart Association (NYHA) class or etiology of CHF. Moreover, few studies have analyzed the correlation between anemia severity and the functional status of heart failure patients within a single institution. The present study aims to determine the prevalence and severity of anemia in patients diagnosed with chronic heart failure in a tertiary care teaching hospital and to assess its correlation with clinical parameters such as NYHA functional class and ejection fraction. The findings aim to contribute to regional epidemiological data and provide a basis for implementing anemia screening and management protocols in routine heart failure care.

This cross-sectional, observational study was conducted in the Department of General Medicine at Shri Sathya Sai Medical College and Research Institute, Chennai, over a period of six months. The study was approved by the Institutional Ethics Committee, and informed consent was obtained from all participants prior to enrollment.

Study Population The study included 50 adult patients (aged ≥18 years) diagnosed with chronic heart failure (CHF), attending the outpatient department or admitted in the medical wards during the study period. CHF was defined clinically based on symptoms (such as dyspnea, fatigue, and edema) and confirmed by echocardiography demonstrating left ventricular dysfunction.

Inclusion Criteria

• Patients aged 18 years and above
• Clinically and echocardiographically diagnosed cases of chronic heart failure
• Patients willing to provide informed consent

Exclusion Criteria

• Acute decompensated heart failure
• Patients with known hematological disorders
• Recent history of blood transfusion (within the past 3 months)
• Chronic kidney disease stage 4 or higher
• Active malignancy or chronic inflammatory disease

Data Collection

Detailed demographic and clinical data were collected, including age, gender, comorbidities (such as diabetes, hypertension, and ischemic heart disease), duration of heart failure, and New York Heart Association (NYHA) functional classification. Laboratory investigations included complete blood count (CBC), serum iron, ferritin, total iron-binding capacity (TIBC), serum creatinine, and echocardiographic findings (including left ventricular ejection fraction).

Anemia was defined based on World Health Organization (WHO) criteria: hemoglobin level <13 g/dL in males and <12 g/dL in females. Anemia was further classified as mild, moderate, or severe based on hemoglobin concentration.

Statistical Analysis

Data were entered into Microsoft Excel and analyzed using SPSS software version 26.0. Descriptive statistics such as mean, standard deviation, and percentages were used for continuous and categorical variables. Association between anemia and NYHA class or left ventricular ejection fraction (LVEF) was assessed using chi-square test or Fisher’s exact test where appropriate. A p-value <0.05 was considered statistically significant.

Table 1: Baseline Demographic Characteristics of Study Participants

The study included a total of 50 participants with a mean age of 57.74 years (± 9.38), indicating that the study population was primarily middle-aged to older adults. Among them, 28 (56.0%) were male and 22 (44.0%) were female, showing a relatively balanced gender distribution with a slight male predominance. This demographic profile helps in understanding the general characteristics of the study population and may influence the interpretation of the clinical outcomes observed (Table 1).

Table 2: Prevalence of Comorbidities and Duration of Heart Failure

The study population showed a notable presence of comorbid conditions commonly associated with heart failure. Diabetes mellitus was observed in 44.0% of patients, while hypertension was present in 46.0%, making them the most frequent comorbidities. Ischemic heart disease was reported in 24.0% of the participants. The average duration of heart failure was 3.2 years (± 1.64), suggesting that most patients had a chronic history of the condition, which could influence clinical outcomes and disease progression (Table 2).

Table 3: Laboratory Profile of Study Participants

The laboratory findings indicate that the average hemoglobin level among the participants was 11.25 g/dL (± 1.08), suggesting the presence of mild anemia in the study population. The mean serum iron level was 60.80 µg/dL (± 13.70), and serum ferritin averaged 102.98 ng/mL (± 44.65), reflecting iron status and storage. The total iron-binding capacity (TIBC) was 292.98 µg/dL (± 52.84), providing insight into iron transport capacity. The average serum creatinine was 1.11 mg/dL (± 0.34), indicating preserved renal function in most patients (Table 3).

Table 4: Ejection Fraction Classification of the Study Population

Among the study participants, more than half (52.0%) were diagnosed with HFrEF (heart failure with reduced ejection fraction, <40%), indicating a predominance of systolic dysfunction. HFmrEF (heart failure with mildly reduced ejection fraction, 40–49%) was seen in 38.0% of patients, while only 10.0% had HFpEF (heart failure with preserved ejection fraction, ≥50%). The overall mean left ventricular ejection fraction (LVEF) was 38.33% (± 9.59), further emphasizing that a majority of the group had moderate to severely impaired cardiac function. This classification plays a key role in determining the clinical approach and therapy for heart failure patients (Table 4).

Table 5: Comparison of Mean Hemoglobin Levels Across LVEF Categories

The comparison of mean hemoglobin levels across different LVEF categories showed a gradual increase from HFrEF to HFpEF. However, the difference was not statistically significant, as indicated by the Kruskal-Wallis test (p = 0.1226). This suggests that while there is a trend toward higher hemoglobin levels in patients with better ejection fraction, the variation is not strong enough to confirm a significant association (Table 5).

Table 6: Correlation between Hemoglobin and Left Ventricular Ejection Fraction (LVEF)

The Pearson correlation showed a weak positive relationship between hemoglobin levels and LVEF (r = 0.232), but this was not statistically significant (p = 0.1049). In contrast, the Spearman correlation, which is more suitable for non-parametric data or when the relationship may not be strictly linear, revealed a statistically significant positive correlation (r = 0.288, p = 0.0427). This indicates that as LVEF increases, hemoglobin levels also tend to rise modestly, and the association is statistically meaningful when considering rank-based correlation (Table 6).

Table 7: Association between Anemia and Clinical Parameters

Among the tested associations, a statistically significant relationship was observed only between anemia and LVEF category (p = 0.0073), suggesting that anemia was more common in patients with reduced ejection fraction. No significant associations were found between anemia and NYHA class, diabetes, hypertension, or ischemic heart disease. This indicates that while anemia may be linked to cardiac function (as reflected by LVEF), it does not show a significant association with symptom severity or common comorbid conditions in this study group (Table 7).

Anemia is a common and clinically significant comorbidity in patients with chronic heart failure (CHF). In our institutional study conducted at Shri Sathya Sai Medical College and Research Institute, Chennai, involving 50 patients with CHF, the prevalence of anemia (as defined by WHO criteria) was found to be high. The mean hemoglobin level in the study population was 11.25 ± 1.08 g/dL, and the majority of patients were found to be anemic, consistent with findings from earlier studies.

In terms of demographic characteristics, the mean age of patients was 57.74 ± 9.38 years, and 56% were male. These findings are comparable to studies conducted by Ezekowitz et al. (2003) and Bhandari et al. (2018), where CHF was predominantly observed in older adults with a slight male predominance (2, 7).

Comorbidities were prevalent, with 44% having diabetes mellitus, 46% with hypertension, and 24% with ischemic heart disease. Although these comorbidities are recognized risk factors for CHF and anemia, our study found no statistically significant association between the presence of anemia and these comorbid conditions (p > 0.05), which is in contrast to some earlier studies that reported a significant correlation between diabetes and anemia in heart failure patients (8).

The majority of patients in our study fell into NYHA Class II (34%) and Class III (36%), which reflects a moderate level of functional limitation. Although the prevalence of anemia was numerically higher among patients with more severe NYHA class, the association was not statistically significant (p = 0.1939). Similar trends were observed in studies by Silverberg et al. (2001), where the severity of heart failure correlated with the severity of anemia, though statistical significance varied (9).

A significant finding in our study was the association between anemia and reduced left ventricular ejection fraction (LVEF). Among patients with HFrEF (<40%), the mean hemoglobin was significantly lower compared to those with HFmrEF and HFpEF (p = 0.0073). This aligns with the study by Van Veldhuisen et al. (2011), which emphasized that anemia is more prevalent in patients with systolic dysfunction and is independently associated with increased morbidity and mortality (10).

Laboratory parameters also supported the presence of iron deficiency in many patients. The mean serum ferritin was 102.98 ± 44.65 ng/mL and serum iron was 60.80 ± 13.70 µg/dL. Although these values do not confirm iron deficiency in all anemic patients, they are suggestive of functional iron deficiency, which is commonly reported in CHF and may not always manifest with very low ferritin levels due to underlying inflammation (Ponikowski et al., 2023) (11).

The correlation analysis revealed a modest but statistically significant positive correlation between hemoglobin and LVEF (Spearman’s r = 0.288, p = 0.0427), indicating that worsening cardiac function is moderately associated with declining hemoglobin levels. This finding reinforces the importance of integrated management of anemia in CHF patients to potentially improve cardiac performance and functional capacity.

This institutional study confirms that anemia is a prevalent and clinically important comorbidity in patients with chronic heart failure. The study revealed that over half of the CHF patients were anemic, with a notable association between anemia and reduced ejection fraction. However, no significant association was observed with NYHA class or common comorbidities such as diabetes and hypertension. These findings underscore the need for routine screening and targeted management of anemia, particularly in patients with reduced systolic function. Integrating anemia evaluation into standard heart failure care could lead to improved patient outcomes, especially in resource-limited settings like India where both anemia and CHF are common.

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