The prognostic importance of subclinical heart failure in stable coronary heart disease patients

Background: In stable coronary heart disease (CHD) patients we aimed to assess the predictive potential of only mild increase of brain natriuretic peptide (BNP) in subjects free from symptoms or diagnostic criteria of heart failure (HF).Methods: We examined 967 patients, at least 6 months after myocardial infarction or coronary revascularization and divided them into three categories: ‘overt HF’ (NYHA II-IV, objective signs of HF, chronic treatment with furosemide and/or spironolactone or history of hospitalisation for HF), ‘subclinical HF (BNP over 150 ng/mL, but no criterion of overt HF)’ and ‘no HF’ (no above mentioned criterion present). Follow-up was done to assess 5-years all-cause mortality.Results: Overt and subclinical HF (by definition) had 38.8% and 9.6% of patients, respectively. In analyses adjusted for classical risk factors and other possible covariates, both overt and subclinical HF were independently associated with increased mortality compared to no HF subjects hazard risk ratio 1.99 (95%CI:1.02–3.91) and 3.01 (95%CI:1.90–4.78), respectively. The risk of total mortality was similar in overt and subclinical HF patients [HRR 1.30 (95%CI: 0.72–2.36). Within overt HF group, those with BNP >150 ng/mL had also higher mortality risk than those with low BNP levels HRR 2.79 (95%CI: 1.67–4.68). The addition of left ventricle ejection fraction into definition of HF groups did not affect main results.Conclusions: Mild increase of BNP in generally stable and asymptomatic CHD patients identifies high individual mortality risk in the same extend that presence of clinically manifest HF.