Heart failure (HF) is a growing problem worldwide: more than 20 million people around the world are affected, and more than 5 million in the United States [1]. The prevalence of HF follows an exponential pattern, and it rises with age. Heart failure affects 6% to 10% of people over the age of 65 years. Although the relative incidence is lower in women than in men, women constitute at least half of the cases of HF because of their longer life expectancy [2].

Acute decompensated heart failure can be defined as the sudden or gradual onset of the signs or symptoms of heart failure requiring unplanned office visits, emergency room visits, or hospitalization [3].

Several prognostication markers have been used in recent years, of which cardiac biomarkers are most widely used in clinical practice. Natriuretic peptides are known to be raised and predict outcomes in both symptomatic and asymptomatic left ventricular impairment. They also predict mortality in the population as a whole regardless of left ventricular systolic function or evidence of cardiovascular disease. Ventricular (NT-pro) BNP production is strongly up-regulated in cardiac failure and locally in the area surrounding a myocardial infarction.Cardiac troponin I (cTnI), in particular, is not expressed by injured or regenerating skeletal muscle and is, therefore, exquisitely specific for myocardial injury [4,5].

A minimal change in IVC diameter with respiration may predict volume overload in patients. In order to supply blood to the lower extremity, the heart pumps an X amount of blood through the common femoral artery (CFA). This volume of blood arrives to the tissue by the distal arterioles and returns to the right ventricle through the venules, small veins, common femoral vein (CFV), and inferior vena cava [6].

The present study evaluated the size and expansibility of femoral vein at discharge and its association with 6-month mortality and readmission in patients with acute decompensated heart failure with reduced ejection fraction. The study aims to determine whether SEFV can be used as a point of care tool to determine the mortality and rehospitalization in patients with heart failure with reduced ejection fraction.

Aims and objectives

Primary Objective:To describe the size, expansibility of femoral vein and BNP at discharge in adult patients with HfrEF.

Secondary Objective

To compare BNP at discharge with SEFV at discharge as predictors of 6-month re-hospitalization or death.

Study Design

Prospective cohort

Study Period

1 year beginning from protocol approval

Study Setting 

Department of Medicine

Sample Size

All Consecutive patients of HfrEF discharged alive from the Department of Medicine over 6 months.

Study Subjects 

All adult patients admitted to the medicine ward and having a documented HfrEF were enrolled after obtaining informed consent for participation in the study. 

Inclusion Criteria

All consented patients >=18 years of age were discharged with the diagnosis of HfrEF.

Exclusion Criteria

• Patients with a DVT in proximal lower limb veins.

• Patients of Chronic Kidney Disease Stage 5d.

• Patients of Chronic Liver Disease.

Ethics Consideration

Approval from the institutional ethics committee was obtained before initiation of the study.

Participant Recruitment Plan

Convenient sampling was done. All consecutive patients were enrolled after obtaining informed consent. The investigator identified all newly admitted patients having documented HfrEF every day. The patients was observed throughout the admission and was subjected to ultrasound evaluation for SEFV before discharge in addition to the BNP levels done at the same time.

Primary Outcome Variable

 6-month mortality or re-hospitalization.

Data Analysis

Data collected was entered into Microsoft Excel spreadsheet and was analyzed using SPSS® software. Quantitative variables were expressed as mean.

Table 1: Following the interpretation of size and expansibility of the femoral vein was used in this study

Description of the test of SEFV

Position of the Patient: Supine with legs extended and groin exposed.

The linear probe of ultrasound was used to assess the size and expansibility of the femoral vein. The size of the femoral vein was assessed keeping the linear ultrasound probe vertically just above the bifurcation of the femoral artery into superficial and deep femoral arteries. The size of the femoral vein and artery was assessed using an area mapping tool.

The present study was aimed to determine the size and expansibility of femoral vein at discharge and its association with 6-month mortality or re-hospitalization in patients with heart failure with reduced ejection fraction. A total of 67 patients with heart failure with reduced ejection fraction were included in the study at the Department of Medicine, Indira Gandhi Medical College, Shimla.

In this study, the proportion of patients who did not survive at 6-months was 32.8% (n=22) out of total 67 patients. (Figure 1)

Figure 1: Distribution Based On Mortality at 6 Months

In our study, general characteristics of the patients were not significantly associated with mortality. (Table 2)

Table 2: Distribution of Patients Based On Mortality and General Characteristics

In this study, Hb levels, Serum iron and ferritin levels, Water restriction and the use of beta-blockers, diuretics, and inotropes was not significantly associated with mortality at 6-months (P>0.05). (Table 3)

Table 3: Association between Mortality and Hb & Iron Profile, Water Restriction and Drugs

In our study, re-hospitalization in 6 months was observed in 33(49.3%) of the patients. (Figure 2)

Figure 2: Re-Hospitalizations within 6 Months

In our study, age, sex, NYHA class, and ejection fraction were not significantly associated with re-hospitalization at 6-months (P>0.05). (Table 4)

Table 4: Distribution of Patients Based On Rehospitalization and General Characteristics

In this study, Hb levels, serum iron and ferritin levels and use of beta-blockers, diuretics, and inotropes were not significantly associated with rehospitalization in 6-months (P>0.05). (Table 5)

Table 5: Association between Re-Hospitalization and Hb, Iron Profile & Drugs

Our study observed mortality AT 6 months was significantly associated with levels of BNP levels on admission and discharge. (p=0.046, p=0.0009) Our study also observed that rehospitalization was not significantly associated with BNP levels on admission and discharge. (Table 6)

Table 6: The Relation between Mortality & Rehospitalization with BNP on Admission and Discharge

Our study observed a significant decrease in Hs Troponin-I at 6-months in comparison to discharge (P=0.02). Hs-Troponin was not significantly associated with mortality (P=0.668). (Table 7)

Table 7: Hs Troponin-I at Admission, Discharge and 6 Months

Our study observed a significant reduction in the expansibility of femoral vein at discharge at 6-months in comparison to at discharge (P<0.0001). (Table 8)

Table 8: Expansibility of Femoral Vein at Discharge and At 6 Months

In our study, there was a significant association between expansibility of femoral vein and BNP at discharge mortality and rehospitalization in 6-months (p<0.05). (Table 9)

Table 9: Relation Between Expansibility Of Femoral Vein With BNP At Discharge,Mortality And Re-Hospitalization

The present study described the size, expansibility of femoral vein and BNP at discharge in adult patients with HfrEF and their relation to 6-month mortality.

In our study, mortality at 6-months was at 32.8% (n=22), while a total of 33 patients (49.2%) were re-hospitalized during follow-up. Many studies have addressed trends in the mortality and survival in patients with HF comparing different time periods in different countries. Based on the Framingham Heart Study, the mortality rate after the diagnosis of HF in the USA was around 10% at 30 days, 20-30% at 1 year, and 45-60% over 5 years of follow-up.55 Conversely, the Rotterdam Study, which included HF patients in Europe, showed lower mortality, with 11% and 41% 50 mortality rates at 1 year and 5 years of follow-up, respectively [7].

Most epidemiological studies demonstrated a trend toward a decrease in mortality rates in HF patients in the last decades. From the 1959-1969 to 1990-1999 time periods, mortality in HF patients is decreased from 70% to 59% in men, and from 57 to 45% in women [8].

In our study, mortality was not significantly associated with age, sex, NYHA class, and ejection fraction. It has been reported that advancing age increases short and long-term mortality in hospitalized heart failure patients. In many studies, no effect of age on mortality has been found. Other previous studies in which an effect of aging was not found may have been too small or included younger patients than seen in epidemiological CHF studies [9,10].

In our study, there was a higher mortality rate among women in our study although this finding was not significant. Also in our study, majority of those admitted with a Higher NYHA class were likely to die or get rehospitalized within a 6-month follow-up although this finding in our study wasn’t significant. EF is the most commonly used clinical measure of left ventricular systolic function and is established as a powerful predictor of death in patients with low LVEF heart failure [11].

Anemia is frequent in patients with heart failure (HF) and prevalence is in the 5%-55% range depending on the criteria used and population studied. In our study, the mortality and rehospitalization rate among patients with reduced Hb levels of 9.1-12 was high at 46.0% and 86.3% respectively, although these results were found to be non-significant. Lupon et al reported that one-year mortality was 17% in patients with anemia and 5% in patients without anemia (P<.001). Iron deficiency, whether absolute or functional, is a frequent finding in HF patients also presenting with anemia, affecting up to 80% of these individuals [12].

Current evidence regarding the effects of diuretics and water restriction on HF outcomes is scant and conflicting. In our study, diuretics therapy and water restricted regime were not associated with a significant decrease in mortality or rehospitalization. Doughty et al in their systemic review found that there was a 31% reduction in the odds of death among patients assigned a beta-blocker (95% confidence interval 11 to 46%), representing an absolute reduction in mean annual mortality from 9.7% to 7.5% [13].

Inotrope administration is a marker of increased mortality in patients with acute heart failure. In our study, a total of 11 patients received inotropic support (16.4%), and among the mortality group, 13.6% had received inotropic support, while among those rehospitalized within 6 months, 31.8% had received inotropes.

Circulating B-type natriuretic peptide (BNP) concentrations strongly predict mortality in patients with heart failure (HF). Both cardiac and extracardiac stimuli influence BNP levels, suggesting that BNP might have a similar prognostic value in patients without HF. In our study, Higher BNP levels at discharge were significantly associated with mortality at 6 months.however, in contrast, higher BNP levels at discharge were not significantly associated with rehospitalization within 6 months. 

In multivariate models including demographic and clinical characteristics, BNP and age were the strongest predictors of death in both patients with and those without HF. In acute care settings and even among outpatients with modestly elevated BNP, the risk for death according to BNP was similar between patients with and those without HF [14].

There have been limited data available and limited studies have been done that compare SEFV with mortality and rehospitalization. In the current study a reduced expansibility of the femoral vein (<1.5) at the time of discharge was significantly associated with increased mortality at 6 months and increased rehospitalization within 6 month follow-up .There was a significant increase in the number of patients with a reduced expansibility of the femoral vein when compared at discharge and 6-month follow-up..This finding could suggest that there might be a development of volume overload over time in such patients. Also, there was a significant association between BNP levels at discharge and the reduced expansibility of the femoral vein. 

Limitation

This was a hospital-based observational study. Incidence of the disease may vary widely depending on the patient population and baseline risk factors. As most of the indoor patients already had multiple medical conditions and there was the presence of multiple confounding factors, the actual results and observations may vary in outdoor stable patients. Other limitations of this study include a relatively small sample size, which affects the ability to generalize these results at the extremes of expansibility values.The unique use of expansibility indices for comparison may also be less accurate as a predictor of volume status than a combined approach also including absolute diameter measurements or invasive procedures.

Size and expansibility of the femoral vein (SEFV) on Ultrasonography is a novel bedside tool to detect the presence of volume overload even in the absence of physical signs in the patient of heart failure. Despite IVC collapsibility being a regularly used method, SEFV can have an advantage over it in the context of easier access and a short span of the learning curve. Although a variety of biomarkers are already in use, the use of SEFV at discharge as a point of care bedside tool can be both inexpensive to the patient and a useful guiding tool to the physician even in the absence of a high-end laboratory setup.

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