michael s
(Michael S)
#1
57 What is mean and model life expectancy in
NYHA I-IV heart failure?
Aidan Bolger
The New York Heart Association (NYHA) first published its
Criteria for diagnosis and treatment of heart diseasein 1928. The ninth
and latest edition, published in 1994,^1 retains an assessment of
the functional capacity of the patient with heart disease (see Table
57.1). The NYHA functional capacity score is an entirely
subjective assessment of a patient’s cardiovascular status and is
independent of objective measures of cardiovascular structure
and function. Despite this it remains a quick, simple and repro-
ducible evaluation of the patient with heart failure. In testament
to this, NYHA class can consistently predict mortality in chronic
heart failure having now been established as an independent
prognostic variable in this condition in many large, epidemio-
logical studies and clinical trials. The majority of patients with
class IV functional status have end stage disease, the poorest
prognosis and represent a relatively small group. Most patients
are therefore classified with class II or III symptoms. Larger
studies have reported mortality data across all NYHA classes.
Typically the mortality rates for one and three years respectively
are, class I/II 82% and 52%, class III 77% and 34% and class IV
41% and 0%.^2
Hospital series include those with acutely decompensated
disease. Whether such patients can be classified according to
NYHA criteria is open to debate, but they might be considered in
class IV. Survival of just 33% at two year follow up has been
reported for this group in a Canadian study.^3 The burden of heart
failure in the United Kingdom is more difficult to appreciate,
based on the analysis of official surveys, as death certification is
based on disease aetiology rather than clinical diagnoses.
The Framingham Heart Study^4 is probably the largest survey of
cardiovascular disease undertaken and has data on over 9000
patients, spanning two generations, with a median follow up of
14.8 years. Mortality data in this series was not based on NYHA
class but simply included those in which a diagnosis of heart
failure had been made. The overall five year mortality rates were
reported as 75% for men and 62% for women with a median
survival of 1.66 years after the onset of congestive heart failure.
