Impact of beta-blocker treatment on the prognostic value of currently used risk predictors in congestive heart failure

AbstractObjectivesThis prospective study tested the impact of beta-blocker treatment on currently used risk predictors in congestive heart failure (CHF).BackgroundGiven the survival benefit obtained by beta-blockade, risk stratification by factors established in the “pre–beta-blocker era” may be questioned.MethodsThe study included 408 patients who had CHF with left ventricular ejection fraction (LVEF) <45%, all treated with an angiotensin-converting enzyme inhibitor or angiotensin type 1 receptor antagonist, who were classified into those receiving a beta-blocker (n = 165) and those who were not (n = 243). In all patients, LVEF, peak oxygen consumption (peakVo2), plasma norepinephrine (NE) and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were determined.ResultsAlthough the New York Heart Association functional class (2.2 ± 0.7 vs. 2.3 ± 0.7), peakVo2(14.4 ± 5.2 ml/min per kg vs. 14.4 ± 5.5 ml/min per kg) and NT-proBNP (337 ± 360 pmol/l vs. 434 ± 538 pmol/l) were similar in the groups with and without beta-blocker treatment, the group with beta-blocker treatment had a lower heart rate (68 ± 30 beats/min vs. 76 ± 30 beats/min), lower NE (1.7 ± 1.2 nmol/l vs. 2.5 ± 2.2 nmol/l) and higher LVEF (24 ± 10% vs. 21 ± 9%; all p < 0.05). Within one year, 34% of patients without beta-blocker treatment, but only 16% of those with beta-blocker treatment (p < 0.001), reached the combined end point, defined as hospital admission due to worsening CHF and/or cardiac death. A beneficial effect of beta-blocker treatment was most obvious in the advanced stages of CHF, because the end-point rates were markedly lower (all p < 0.05) in the group with beta-blocker treatment versus the group without it, as characterized by peakVo2<10 ml/min per kg (26% vs. 64%), LVEF ≤20% (25% vs. 45%), NE >2.24 nmol/l (18% vs. 40%) and NT-proBNP >364 pmol/l (27% vs. 45%), although patients with beta-blocker treatment received only 37 ± 21% of the maximal recommended beta-blocker dosages.ConclusionsThe prognostic value of variables used for risk stratification of patients with CHF is markedly influenced by beta-blocker treatment. Therefore, in the beta-blocker era, a re-evaluation of the selection criteria for heart transplantation is warranted