Nhóm thứ hai đã được thiếu đại diện trong các thử nghiệm cho đến nay. Nói chung, các thuốc chẹn cần được bắt đầu ở liều rất thấp, với liều từ từ tăng lên, dưới sự giám sát của chuyên gia, với liều mục tiêu nếu dung nạp. | available to support the use of p blockers in chronic heart failure as the benefits supplement those already obtained from angiotensin converting enzyme inhibitors. Carvedilol is now licensed in the United Kingdom for use in mild to moderate chronic stable heart failure although at present its use is still not recommended in patients with severe symptoms New York Heart Association class IV . This latter group has been underrepresented in the trials to date. In general p blockers should be started at very low doses with the dose being slowly increased under expert supervision to the target dose if tolerated. In the short term there may be a deterioration in symptoms which may improve with alterations in other treatment particularly diuretics. Summary of the cardiac insufficiency bisoprolol study II CIBIS II Randomised double blind parallel group study 2647 participants class III-IV moderate to severe according to classification of the New York Heart Association Bisoprolol increased in dose to a maximum of 10 mg a day Trial stopped because of significant mortality benefit in patients treated with bisoprolol a 32 reduction in all cause mortality b 32 reduction in admissions to hospital for worsening heart failure c 42 reduction in sudden death CIBIS II Investigators and Committee Lancet 1999 353 9-13 Dose and titration of p blockers in large placebo controlled heart failure trials p Blocker Initial dose mg Weekly titration schedule total daily dose mg Target total daily dose mg 1 2 3 4 5 6 7 8-11 12-15 Metoprolol MDC trial 5 10 15 20 50 75 100 150 NI NI 100-150 Carvedilol US trials NI NI 25 NI 50 NI NI 50 Bisoprolol CIBIS II 5 5 5 5 10 10 References WaagsteinF et al Lancet 1993 342 1442-6 Packer M et al N Engl J Med 1996 334 1349-55 and CIBIS II Investigators and Committee Lancet 1999 353 9-13 . NI no increase in dose. Antithrombotic treatment In patients with chronic heart failure the incidence of stroke and thromboembolism is .
