Prognostic Value of Haemoglobin Levels at Discharge in Older Patients Admitted With Heart Failure.
Nicolas Wisniacki, Pam Aimson, Shakeel Raza, Chris Manning, Alejandra Abramovsky,Vinod Gowda, Michael Lee, Jason Pyatt.
Department of Medicine,
University of Liverpool & Department of
Royal Liverpool and Broadgreen University Hospitals.
Chronic heart failure (CHF) is a common syndrome affecting more than 20 million people worldwide and approximately 7 million people in European community. The incidence and prevalence of CHF have been shown to increase sharply with age.
It carries with it a poor prognosis; 12-week mortality was 14% in the recently reported Euroheart survey.
Anaemia as a co-factor in CHF has not been well evaluated and its contribution is ill defined. Anaemia is common in severe CHF and is reported to be predictor of death. Several cross-sectional studies have confirmed that anaemia is common in patients with CHF and its severity correlates positively with the severity of CHF. However, the importance of haemoglobin levels especially in hospitalised patients with CHF has not been explored.
The aim of our study was to evaluate the prognostic value of haemoglobin levels at discharge in elderly patients admitted with CHF.
Methods: We prospectively recruited a total of 405 older patients (> 65 years old) admitted with CHF from November 1999 to May 2001.Diagnosis of heart failure was made by the treating physician based on history, physical examination ,Chest x-ray, ECG and Echocardiogram. A record was also made of their current medications and other co-morbidity. They also had laboratory investigations with particular emphasis on full blood counts and renal function. Haemoglobin at discharge was also recorded in these patients. According to WHO classification anaemia was defined as haemoglobin level of <12 gm/dl. Each patient was further classified based on NYHA classification.
Patients with severe valve disease, serious co-morbidity and with an alternative diagnosis were excluded from the study.
The patients were followed up for a mean period of 2.7 +/- 0.46 years in the Heart Failure clinic by the Heart Failure Specialist Nurse under the supervision of consultant cardiologist with special interest in heart failure.
Results: Of the 405 patients screened, 95 died during hospitalisation.34 patients did not have haemoglobin levels checked at discharge and were therefore excluded from the analysis. The final number of patients included was 276(mean age of 79.4 +/- 7.5).
122 (44.1%) patients were male. The mean NYHA class on admission was 3.11 +/- 0.64.The mean haemoglobin level at discharge was 12.32 +/- 1.95 .
117 patients (42%) had anaemia at discharge. The variables associated with anaemia at discharge were female gender, creatinine levels and length of stay in hospital ( all p<0.001).
During the follow up period 90 patients (32.6%) died. In a multivariate Cox proportional hazard model, haemoglobin levels at discharge were associated with mortality(HR 0.84, C I 95% 0.75-0.96, P= 0.009) independent of creatinine levels, gender, treatment with ACE –inhibitors,age,length of stay and severe left ventricular systolic dysfunction.
Conclusion: Our study has shown that Haemoglobin level at discharge is an independent predictor of mortality in elderly patients with heart failure. It therefore important that anaemia is recognised early in such patients and every effort is made for its further investigation and correction.
Discussion: Anaemia in elderly patients should never be regarded as normal physiological response to aging. Underlying causes must be investigated and treated in a similar manner to that used in younger adults.
Anaemia as a cofactor in CHF has not been well evaluated and its contribution is ill defined.
The following factors have been considered:
• There may be reduced intestinal iron uptake associated with cardiac cachexia and malabsorption.
• CHF activates the renin-angiotensin-aldosterone system and vasopressin, resulting in sodium and water retention and dilutional anaemia.
• CHF can lead to renal dysfunction due to renal vasoconstriction and ischemia resulting in an increase in erythropoietin. Usually renal anaemia develops in chronic renal dysfunction with serum creatinine over 3.5 mg/dl or a creatinine clearance below 30ml/min.
• Treatment of the disease underlying CHF, principally coronary artery disease with gents such as aspirin and warfarin can contribute to blood loss and anaemia due to gastrointestinal bleeding.
• High doses of ACE-inhibitors can impair the response to erythropoietin treatment haemodialysis patients.
Several cross-sectional studies have confirmed that anaemia is common in patients with CHF and its severity correlates positively with the severity of CHF. All recent outcome studies have shown that anaemia is associated with mortality rates beyond those explicable from heart failure severity.
The importance of anaemia in CHF has been highlighted by data from the SOLVD study where anaemia was found to be a risk factor for mortality.
Szachneiwicz J et al.(Int. J Cardio. Aug. 2003) has also concluded in their study that anaemia is significant predictor of poor outcome in unselected patients with CHF.Correction of low haemoglobin level may become an interesting therapeutic option for CHF patients.
A placebo-controlled randomised trial showed that the normalization of haemoglobin levels in anaemic patients with CHF improved peak oxygen uptake and exercise performance.
Large clinical trials are required to define the true potential of anaemia therapy in CHF.
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