PLASMA PROATRIAL NATRIURETIC FACTOR IS PREDICTIVE OF CLINICAL STATUS IN PATIENTS WITH CONGESTIVE-HEART-FAILURE

Atrial stretch results in myocyte release of the prohormone atrial natriuretic factor (1-126). The N-terminal (1-98) fragment, proatrial natriuretic factor (proANF) is released on an equimolar basis with the C-terminal (99-126) active hormone and may be assayed simply due to in vitro stability. This study was undertaken to evaluate the relation between proANF and routinely available measures of clinical status. ProANF was sampled from 202 patients (median age 68 years [range 15 to 85], 77% men) recruited from an active outpatient heart failure clinic. Patients were subgrouped according to New York Heart Association functional class, radionuclide ejection fraction (EF), echocardiographic left ventricular (LV) end-diastolic diameter, and Doppler-determined systolic pulmonary arterial pressure. The median proANF (pmol/L) values for patients in New York Heart Association classes I, II, III, and IV were 725, 1,527, 1,750, and 5,172, respectively. The proANF value for the group with EF >40% was 1,534 versus 1,993 for EF less than or equal to 40% (p <0.05). The value for the group with LV diameter <60 mm was 838 versus 1,751 for LV diameter greater than or equal to 60 mm (p <0.01). the value for the group with systolic pulmonary artery pressure <45 mm Hg was 1,241 versus 2,660 for systolic pulmonary artery pressure greater than or equal to 45 mm Hg (p <0.01). ProANF correlated better than the other variables with New York Heart Association functional class and was more closely associated with noninvasive measurements than New York Heart Association functional class. Odds ratio estimates demonstrated a substantially increased risk of LV dysfunction and dilatation, pulmonary hypertension, and New York Heart Association functional class III or IV with increasing proANF valves. These data clearly indicate that the concentration of proANF is related to the degree of clinical heart failure. Analysis is simple and should be of practical value as a supplement in the routine assessment of cardiac status in this heterogeneous population.