#445 Octogenarians in hemodialysis: not everyone ages the same
Authors: Sirvent Ana Esther , Vigueras María Rosa , Enriquez Ricardo , Jiménez Celia , Pérez Antonio Pérez , Abad Juan Mariano Pérez , Merino Guadalupe Ruiz , Penalva Maria Rosa Gea , Fajardo Concepción Alcázar , Montiel Francisco , Andreu Alberto 
Published: May 2024

Abstract

Background and Aims
The average life expectancy in Western Europe in 2022 was 79 years for males and 84 years for females. Over the past years, the number of ageing patients in hemodialysis (HD) has increased significantly in all countries. There are several considerations for dialysis maintenance in older patients with an increased burden of age-related problems. It is important to identify the specific characteristics of this elderly population to develop appropriate care strategies and to estimate future needs for renal support services. The aim was to describe the clinical characteristics of our prevalent dialysis population by age, with particular reference to octogenarians.

Method
In this retrospective observational study between 2008 and 2022, the medical charts of 253 prevalent HD patients in a referral university hospital were analyzed. Patients were divided into four groups according to their age (four age groups: ≤60, 61–70, 71–80, 80&gt; years old). Patient demographics and comorbidities were compared between age groups. Percentage and type of AVF (arteriovenous fistula), primary failures, and AVF reparations were recorded at onset of HD and at follow-up. Interdialytic weigh gain (average for pre-dialysis measurement of three hemodialysis sessions per week for two weeks) was also informed.

Results
57 patients older than 81 years underwent dialysis (mean age 85.2±3.3 years), 31 (54%) older than 84 years (11 women, 20 men). 48% of patients over the age of 80 had to start HD urgently. In octogenarian, length on time in hemodialysis was 4.3 ± 6.46 years, they were no differences based on age; vintage HD in women and men older than 84 years was 5.2 ± 3.4 years and 5.3 ± 3.7 years, respectively. Females accounted for 40.4%, higher than other age groups, but not statistically significant. None of the over-80s self-reported active smoking, with differences between groups (p=0,000). Diabetes was less common in the youngest and oldest patients (23.9%vs 49.1%vs 56.8% vs 43.9% for patients ≤60, 61-70, 71-80 and 80&gt;age, respectively, p=0.001). Similar trends were observed for ischemic heart disease and peripheral vascular disease (3%vs23,6%vs25,7% vs15,7% and 9%vs27,3%vs24,3vs15,8%; p=0,000 and p=0,035, respectively). Among octogenarians, 36.8% had experienced heart failure, the highest proportion of any age group (14,9%vs23,6%vs25,7% vs36,8% for patients ≤60, 61-70, 71-80 and 80&gt;age, p=0.046), but interdialytic gains were not greater in this group than in others (70%vs53,7%vs45,9%vs47,4% for patients ≤60, 61-70, 71-80 and 80&gt;age, p=0.019). Chronic lung disease occurred significantly less often in octogenarians compared to younger patients (17,9%vs30,9%vs36,5%vs15,2% in the ≤60, 61-70, 71-80 and 80&gt; age groups respectively (p=0.026). Cerebrovascular disease and active neoplasm did not differ based on age. Underlying chronic kidney disease was unknown in 28.1% of patients over 80 years of age. Diabetic nephropathy was the main known condition of nephropathy (16,4%vs27,3%vs23%vs15,8% for patients ≤60, 61-70, 71-80 and 80&gt;age, p=0.052). (see Table 1).
In all age groups, AVF was the most common VA in incident and in prevalent HD patients (52,2%vs61,8%vs62,2%vs 77,2% and 82,1%vs80%vs86,5%vs 78,9 % in the ≤60, 61-70, 71-80 and 80&gt; age groups respectively (p=0,086, p=0,640)). Radio-cephalic made up the largest proportion of AVFs in the total population. VA primary failure is more common in octogenarians (1,5%vs16,4%vs10,8%vs19,3% for patients ≤60, 61-70, 71-80 and 80&gt; age, p=0.010). There were no differences in the need for AVF repair between groups (see Table 2).

Conclusion
Our octogenarian HD population is a selected population with a lower-than-expected comorbidity burden compared to younger age groups. Very elderly patients are more compliant and survive more than five years after HD initiation. Although vascular access may be more difficult to achieve initially, the outcome is comparable to that of younger patients in our study. Strategies to best manage this vulnerable hemodialysis population remain to be explored.