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.
Usefulness of a clinical risk score to predict the response to cardiac resynchronization therapy
