Circulation. 1994 Oct;90(4):1765-73. doi: 10.1161/01.cir.90.4.1765.
Functional benefit in heart failure due to idiopathic dilated cardiomyopathy has been observed after beta-blockade, but improvement in survival has not been established in a large-scale randomized trial. This was the main objective of the Cardiac Insufficiency Bisoprolol Study (CIBIS).
Six hundred forty-one patients with chronic heart failure of various etiologies and a left ventricular ejection fraction of < 40% entered this placebo-controlled, randomized, double-blind study. Patients were in New York Heart Association functional class III (95%) or IV (5%) at inclusion. All received background diuretic and vasodilator therapy (an angiotensin-converting enzyme inhibitor in 90% of cases). A total of 320 patients was randomized to bisoprolol and 321 to placebo. Mean follow-up was 1.9 years. Bisoprolol was well tolerated without between group difference in premature treatment withdrawals (82 on placebo, 75 on bisoprolol; NS). The observed difference in mortality between groups did not reach statistical significance: 67 patients died on placebo, 53 on bisoprolol (P = .22; relative risk, 0.80; 95% confidence interval, 0.56 to 1.15). No significant difference was observed in sudden death rate (17 on placebo, 15 on bisoprolol) or death related to documented ventricular tachycardia or fibrillation (7 on placebo, 4 on bisoprolol). Bisoprolol significantly improved the functional status of the patients; fewer patients in the bisoprolol group required hospitalization for cardiac decompensation (90 on placebo versus 61 on bisoprolol, P < .01), and more patients improved by at least one New York Heart Association functional class (48 on placebo versus 68 on bisoprolol, P = .04) by the end of follow-up period.
These results confirm previous trials evidence that a progressively increasing dose of beta-blocker in severe heart failure confers functional benefit. Subgroup analysis suggested that benefit from beta-blockade therapy was greater for those with nonischemic cardiomyopathy. However, improvement in survival while on beta-blockade remains to be demonstrated.
β受体阻滞剂治疗特发性扩张型心肌病所致心力衰竭可带来功能改善，但大规模随机试验尚未证实其能提高生存率。这是心脏不全比索洛尔研究（CIBIS）的主要目的。
641例病因各异、左心室射血分数<40%的慢性心力衰竭患者进入这项安慰剂对照、随机、双盲研究。入组时患者为纽约心脏协会心功能Ⅲ级（95%）或Ⅳ级（5%）。所有患者均接受背景利尿剂和血管扩张剂治疗（90%的患者使用血管紧张素转换酶抑制剂）。共320例患者随机分组接受比索洛尔治疗，321例接受安慰剂治疗。平均随访1.9年。比索洛尔耐受性良好，两组间提前退出治疗的情况无差异（安慰剂组82例，比索洛尔组75例；无显著性差异）。两组间观察到的死亡率差异未达到统计学显著性：安慰剂组67例患者死亡，比索洛尔组53例（P = 0.22；相对风险，0.80；95%置信区间，0.56至1.15）。猝死率（安慰剂组17例，比索洛尔组15例）或与记录的室性心动过速或颤动相关的死亡率（安慰剂组7例，比索洛尔组4例）无显著差异。比索洛尔显著改善了患者的功能状态；比索洛尔组因心脏失代偿需要住院的患者更少（安慰剂组90例，比索洛尔组61例，P<0.01），随访期末功能至少改善一个纽约心脏协会心功能级别的患者更多（安慰剂组48例，比索洛尔组68例，P = 0.04）。
这些结果证实了先前试验的证据，即重度心力衰竭患者逐渐增加β受体阻滞剂剂量可带来功能改善。亚组分析表明，非缺血性心肌病患者从β受体阻滞剂治疗中获益更大。然而，β受体阻滞剂治疗时生存率的改善仍有待证实。
