Heart failure in a district general hospital: are target doses of beta-blockers realistic?

Background: Carvedilol therapy reduces mortality in patients with chronic heart failure. Multi-centre studies suggest a low first dose failure rate and high levels of tolerability to carvedilol. Little is known, however, concerning the eligibility and tolerance to treatment with carvedilol within a district general hospital setting. Aim: To evaluate the eligibility and tolerance of patients with heart failure to carvedilol within a district general hospital. Design: Prospective clinical audit analysis. Methods: We assessed 100 heart failure patients eligibility to commence carvedilol therapy. In those who satisfied clinical criteria, we evaluated first dose failure rate, target dose achievement, reasons for intolerance, heart rate and blood pressure reduction and resource requirements over a six-month period. Results: Of 100 patients, 16% had contra-indications to commence carvedilol and 22% were receiving a beta-blocker as part of their existing heart failure therapy. Although 62% satisfied eligibility criteria, 1% refused therapy, thus 61% were initiated on carvedilol. The first dose failure rate was 11.5% and 6.6% of patients achieved 'target dose'. Mean heart rate and systolic blood pressure reductions were 15 (SE 1.2)bpm and 17 (SE 1.7) mmHg, respectively. Resource requirements included 155 hours of work-time for a trained heart failure specialist nurse and doctor. Conclusions: In the general setting, eligible patients appear to display a high first dose failure rate, poor tolerance to higher doses and achievement of a 'target dose' of carvedilol. Responses to adrenergic blockade were similar to previously published data, irrespective of the final tolerated dose, suggesting that the concept of achieving a 'target dose' may not be clinically useful. Guidelines and treatment protocols for heart failure should reflect not only what is considered gold standard, but also what is practical in general hospitals.