A CASE-CONTROLLED STUDY OF DETERMINANTS OF KIDNEY DYSFUNCTION IN PATIENTS WITH CONGESTIVE CARDIAC FAILURE IN PORT HARCOURT, NIGERIA
Background: Congestive cardiac failure is a public health problem, with the prevalence
increasing with increase in age. Renal function remains an underappreciated prognostic factor
in heart failure and many patients with heart failure have been reported to have some form of
renal impairment which has contributed to increase morbidity and mortality. However,
studies of the determinants of renal impairment in patients with CCF in Nigeria are sparse.
Objective: This study sought to determine the prevalence of renal impairment and the risk
factors/determinants of renal impairment in patients with congestive cardiac failure in the
University of Port Harcourt Teaching Hospital.
Materials and methods: This was a case-controlled study in which 146 patients with
congestive cardiac failure aged between 18-64 years were compared with 146 age- and sex
matched controls without CCF to determine factors associated with renal dysfunction.
Congestive cardiac failure was diagnosed using the modified Framingham criteria, while
renal impairment was defined as eGFR of <90 ml/min/1.73m2. Data entry and analysis were
done using SPSS-20. Pearson’s coefficient of correlation was used to establish association
among continuous variables. Risk factors associated with renal dysfunction in CCF were
identified using logistic regression analysis, with confidence level set at 95% to measure the
strength of association between renal dysfunction and congestive cardiac failure. The level of
significance was set at p<0.05.
Results: A total of 146 patients with CCF were studied, with a mean age 55.0 ± 6.7 years.
Males constituted 50.7% with a mean age of 56.1 ± 7.8 years for males (range: 26-64 years),
while females constituted 49.3% with a mean age of 53.9 ± 9.4 years (range: 26-64 years).
There was no statistically significant difference between the males and females [p= 0.995].
Seventy percent of these cases were above 50 years of age. A total of 125 of the cases had
renal function impairment, with the grades of CKD as follows: Grade 1 (14.4%), grade 2
(38.4%), grade 3 (41.7%), grade 4 (5.5%). None was in grade 5.
The dominant risk factors for renal impairment in the patients with renal impairment were
age >50 years (OR=5.61, 95% CI=4.41-6.23), male gender (OR=1.78, 95% CI=1.23-2.31),
poorly controlled hypertension (OR=5.67, 95% CI=4.32-6.21) and diabetes mellitus
(OR=4.00, 95% CI=3.72-4.51). High dose loop diuretics, diastolic dysfunction and
hyponatremia were not found to be significant risk factors in this study.
Conclusion: Findings from this study showed a high prevalence of renal function
impairment in patients with CCF. The findings are similar to previous studies in other parts of
Nigeria. Co-morbid hypertension and diabetes, which are also risk factors for CKD, were the
dominant risk factors for renal impairment in CCF patients. There is need for the prevention
and strict control of these factors to reduce the incidence of renal impairment in CCF patients.