A propensity matched study of New York Heart Association class and natural history end points in heart failure.
Pubmed ID: 17293201
Pubmed Central ID: PMC3129268
Journal: The American journal of cardiology
Publication Date: Feb. 15, 2007
Affiliation: University of Alabama at Birmingham, Birmingham, Alabama, USA. email@example.com
MeSH Terms: Humans, Male, Female, Aged, United States, Middle Aged, Clinical Trials as Topic, Proportional Hazards Models, Heart Failure, Chi-Square Distribution, Prognosis, Severity of Illness Index, Statistics, Nonparametric
Grants: K23 AG019211, R01 HL085561, 1-K23-AG1911-04, 1-R01-HL085561-01, K23 AG019211-04, P50-HL077100, R01 HL085561-01, P50 HL077100
Authors: Ahmed A
Cite As: Ahmed A. A propensity matched study of New York Heart Association class and natural history end points in heart failure. Am J Cardiol 2007 Feb 15;99(4):549-53. Epub 2006 Dec 28.
- Digitalis Investigation Group (DIG)
- Systolic Blood Pressure Intervention Trial (SPRINT)
- Systolic Blood Pressure Intervention Trial Primary Outcome Paper (SPRINT-POP) Data
The association between higher New York Heart Association (NYHA) functional class and poor outcome in heart failure (HF) is well known. However, to what extent these associations are confounded by covariates such as age, the severity of disease, and co-morbidity burden is unknown. In the Digitalis Investigation Group (DIG) trial, 2,441 of the 7,788 patients with chronic HF had NYHA class III or IV symptoms. Propensity scores for NYHA classes III and IV were calculated for each patient and were then used to match 1,863 patients in NYHA classes III and IV with 1,863 patients in NYHA classes I and II. Kaplan-Meier and matched Cox regression analyses were used to estimate associations of NYHA class III or IV with mortality and hospitalizations during a median of 37 months of follow-up. Compared with 34% (641 of 1,863) patients in NYHA classes I and II (mortality rate 1,175 in 10,000 person-years of follow-up), 42% (777 of 1,863) patients in NYHA classes III and IV (mortality rate 1,505 in 10,000 person-years) died from all causes (hazard ratio 1.29, 95% confidence interval [CI] 1.14 to 1.45, p <0.0001). Hospitalizations due to all causes occurred in 66% (1,232 of 1,863) patients in NYHA classes I and II (hospitalization rate 3,898 in 10,000 person-years) and 71% (1,322 of 1,863) patients in NYHA classes III and IV (hospitalization rate 4,793 in 10,000 person-years) (hazard ratio 1.16, 95% CI 1.05 to 1.28, p = 0.003). The hazard ratios for patients in NYHA classes III and IV, compared with those for those in NYHA classes I and II, for other outcomes were 1.29 for cardiovascular mortality (95% CI 1.12 to 1.48, p <0.0001), 1.49 for HF mortality (95% CI 1.20 to 1.84, p <0.0001), 1.18 for cardiovascular hospitalization (95% CI 1.06 to 1.32, p = 0.002), and 1.17 for HF hospitalization (95% CI 1.03 to 1.34, p = 0.017). In conclusion, baseline NYHA class is a marker of hospitalization, disease progression, and mortality in a wide spectrum of ambulatory patients with chronic HF.