Association of Early Heart Failure Symptoms and Subsequent Heart Failure Hospitalizations and Mortality among Dialysis Patients.

KEY POINTS: Patients treated with dialysis have a high burden of heart failure symptoms and functional limitations. Higher burden of heart failure symptoms are associated with higher rates of subsequent heart failure hospitalizations. Higher burden of symptoms are associated with higher risk of death.

BACKGROUND

Diagnosing heart failure (HF) in dialysis patients is challenging because of overlapping symptoms of volume overload. The Kansas City Cardiomyopathy Questionnaire (KCCQ) is a health status questionnaire measuring HF symptoms and functional limitations, with lower scores indicating greater burden.

METHODS

We studied 625 Chronic Renal Insufficiency Cohort study participants who developed ESKD and had KCCQ scores post-ESKD diagnosis treated with hemodialysis or peritoneal dialysis. The primary outcomes were rates of HF hospitalization, 30-day HF readmission, and all-cause mortality. KCCQ was modeled dichotomously (<75 versus ≥75) and continuously (per five-point decrement). Poisson regression with robust standard errors was used to test the association of KCCQ score with each outcome.

RESULTS

Among 625 participants (mean age 59 years; 60% male; 87% on hemodialysis), median follow-up from KCCQ evaluation was 6.8 (interquartile range, 3.2-12.0) years. Those with KCCQ <75 had nearly twice the rate of HF hospitalizations (15.4 versus 8.4/100 person-years) compared with KCCQ ≥75. Each five-point decrement in KCCQ was associated with 9% higher adjusted relative risk (aRR) of HF hospitalization ( P = 0.0003), 7% higher aRR of 30-day HF readmission ( P = 0.03), and 6% higher aRR of all-cause mortality ( P < 0.001). Stratified by HF subtype, patients with HF with reduced ejection fraction and KCCQ <75 had 81% higher aRR of HF hospitalization versus those with KCCQ ≥75 ( P = 0.02). Decline in KCCQ by ≥5 from pre-ESKD to post-ESKD was associated with >40% increase in aRR of all-cause mortality ( P = 0.02).

CONCLUSIONS

Higher HF symptom burden and functional limitations at dialysis initiation are independently associated with increased risk of HF hospitalization and all-cause mortality, suggesting that the KCCQ score may help predict outcomes early in the course of treatment.