Correspondence

Heart Failure — Incidence and Survival

N Engl J Med 2003; 348:660February 13, 2003

Article

To the Editor:

Levy et al. (Oct. 31 issue)1 report that the incidence of heart failure has declined among women but not among men, whereas survival after its onset has improved in both sexes. In an accompanying editorial, Redfield states, “If we are to understand why the incidence of heart failure is changing, information about changes in the incidence and outcomes of conditions that cause heart failure should also be assessed.”2 This is certainly true.

Heart failure is not a disease. It is an abnormal physiological condition caused by many different diseases, such as coronary atherosclerosis, hypertension, myocarditis, valvular heart disease, and alcoholism, and each disease has a different incidence of heart failure. Furthermore, each disease may respond differently to standard therapy such as treatment with diuretics, cardiac glycosides, angiotensin-converting–enzyme inhibitors, and other vasodilators. Thus, inclusion of all causes of heart failure without accounting for the proportions of subjects with these diseases in each group, as in the study by Levy et al., will influence the apparent overall incidence of heart failure, as well as conclusions about therapeutic efficacy. For example, a reduction in the incidence of heart failure might be explained by a decreased prevalence and increased control of hypertension.2

Francis J. Haddy, M.D., Ph.D.
211 Second St. NW, Rochester, MN 55901-2896

2 References

1. 1

   Levy D, Kenchaiah S, Larson MG, et al. Long-term trends in the incidence of and survival with heart failure. N Engl J Med 2002;347:1397-1402
   Full Text | Web of Science | Medline

2. 2

   Redfield MM. Heart failure -- an epidemic of uncertain proportions. N Engl J Med 2002;347:1442-1444
   Full Text | Web of Science | Medline

Author/Editor Response

We agree with Dr. Haddy that heart failure is not a homogeneous disease but, rather, a clinical syndrome with multiple contributing causes. Furthermore, it is likely that trends in the incidence of heart failure and associated mortality differ among its multiple causes. We are examining long-term trends in the prevalence of various risk factors and in their relative risks of heart failure. Despite etiologic heterogeneity, heart failure — irrespective of its underlying cause — is a condition associated with high rates of morbidity and mortality and high health care costs. Additional research to understand long-term trends in the incidence of and mortality due to heart failure, as well as to characterize the changing contributions of underlying risk factors, will help direct future prevention efforts.

Daniel Levy, M.D.
Satish Kenchaiah, M.D.
Ramachandran S. Vasan, M.D.
National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA 01702