Introduction:
Appropriate selection of patients (pts) with heart failure (HF) who may benefit from cardiac resynchronization therapy (CRT) is difficult. We sought to identify a clinical risk score to better risk stratify patients prior to CRT implantation.
Methods:
Pts undergoing CRT at Mayo Clinic from 2000 –2005 were included. Multiple clinical variables (age, gender, anemia (Hgb <10g/dL), RF (creatinine clearance ≤ 60ml/min/1.73m
2
), hyponatremia (Na ≤130mEq/L), elevated BNP level (>500pg/ml), etiology, EF ≤20%, and advanced HF (NYHA functional class III–IV) were assessed with outcomes following CRT. Multivariate analysis was used to determine a clinical risk score.
Results:
A total of 496 patients (80% males) age 68 ± 12 years (62% ischemic cardiomyopathy, EF 22% ± 8%) were included. In univariate analysis relative risk (RR) was > 1 for RF (RR 1.8, CI 1.3–2.8; p = 0.002), anemia (RR 3.3, CI 1.8 –5.5; p = 0.001), hyponatremia (RR 3.4, CI 1.4 – 6.9; p = 0.008), elevated BNP (RR 2.9, CI 1.6 –5.7; p < 0.001), ischemic cardiomyopathy (ICM) (RR 1.8, CI 1.2–2.7; p < 0.002), EF ≤ 20% (RR 1.5, CI 1.0 –2.1; p = 0.033), and advanced HF (RR 2.5, CI 1.5– 4.9; p < 0.001). Following multivariate analysis RF, anemia, ICM, and advanced HF remained significant predictors of poor outcome (p >0.01 for all). Survival with 3 or more of these clinical risk factors was significantly worse than with less risk factors (p <0.01, Figure
).
Conclusions:
Pre-implant clinical risk factors including anemia, RF, ICM and advanced HF predict worse outcome following CRT with ≥3 variables predicting >2-fold increased risk of death or heart transplantation. These factors should be considered when selecting pts prior to CRT.
Clinical risk factors for the prediction of acute kidney injury post cardiac resynchronization therapy in an elderly population
