P1522THE RELATIONSHIP BETWEEN AORTIC STENOSIS AND NORTALITY RATE: A PROSPECTIVE COHORT STUDY IN JAPANESE HEMODIALYSIS PATIENTS
Authors: Sasakawa Yuji , Inaguma Daijo 
Published: June 2020

Abstract

Background and Aims
Aortic stenosis (AS) in Japanese hemodialysis (HD) patients is sometimes pointed out by periodic transthoracic echocardiography. In general population, heart failure symptoms become severer with progress of AS. In HD patients, there is a possibility that AS cause blood pressure decline and congestive heart failure which are one of the reasons for censoring HD. There were no large-scale prospective observational studies relating to cardiovascular (CV) events and mortality in HD patients with AS, therefore we investigated whether AS was associated with incidence of CV events and mortality in HD patients.

Method
This study was a prospective cohort analysis which 4 facilities in Japan participated. The subjects who were over 20 years and underwent maintenance HD for at least 12 months were enrolled at timing of receiving transthoracic echocardiography. Patients were classified into following 2 group (AS group: mean pressure gradient (PG) ≥ 20 mmHg or aortic valve area (AVA) ≤ 1.0 cm2 or maximum blood velocity (Vmax) ≥ 2.0 m/s, no AS group: others). Four hundred sixty-four patients were followed up for 2 years. The primary outcome was defined as all-cause mortality. The secondary outcomes were incidences of CV events, stroke and hospitalization due to peripheral artery disease (PAD). Baseline was set at the time of transthoracic echocardiography examination. We compared the mortality and incidences of events between the 2 groups by a multivariate Cox proportional hazard model. In addition, we extracted risk factors relevant to AS by a multivariate logistic regression model.

Results
There were 79 patients (17.0 %) in the AS group among 464 patients. Older age and longer dialysis vintage were significantly associated with comorbidity of AS (multivariate-adjusted odds ratio [OR], 1.06; 95% confidence interval [CI], 1.03-1.10; p &lt; 0.001, OR, 1.05; 95% CI, 1.01-1.08; p = 0.01, respectively). Meanwhile, gender, diabetes mellitus and serum phosphate were not associated with comorbidity of AS. During follow up period (median, 2.3 years), 31 patients (6.7 %) died. There was no significant difference in all-cause mortality between the 2 groups (multivariate-adjusted hazard ratio [HR] for no AS group, 0.68; 95% CI, 0.24 – 1.91; p = 0.46). Furthermore, there were no significant associations between comorbidity of AS and the 3 secondary outcomes (HR, 0.25; 95% CI, 0.03 – 2.00; HR, 1.33; 95% CI, 0.34 – 5.21; HR, 1.50; 95%CI, 0.36 – 6.29, respectively). There were also no significant associations between comorbidity of severe AS defined as Vmax ≥ 2.0 m/s to ≥ 3.0 m/s and all the outcomes including all-cause mortality. On the other hand, tumor bearing was a risk factor for all-cause mortality (HR, 1.65; 95% CI, 1.04 - 2.61), and hypoalbuminemia was a risk factor for mortality from infection (HR, 0.13; 95% CI, 0.02-0.90).

Conclusion
This research showed that there were also no significant associations between comorbidity of AS and outcomes such as all-cause mortality, incidence of CV events, stroke, and PAD during the follow-up period of 2 years. The death caused by infection and malignant tumor accounted for more than 50 % of total all-cause death. It indicates that physical condition and tumor-bearing affect the mortality stronger than AS in a short term. We continue annual follow up and evaluate the impact of AS itself and vascular calcification causing AS after a long term like 5 years.