[Status of β-blocker use and heart rate control in Chinese patients with stable coronary artery disease].

OBJECTIVE: To observe the current status of β-blocker (BB) use and heart rate control in Chinese patients with stable coronary artery disease (SCAD) based on subgroup data of the prospective observational longitudinal registry of patients with stable coronary artery disease (CLARIFY).

METHODS: The CLARIFY study is an international prospective observational registry of outpatients with SCAD. From November 2009 to July 2010, patients with SCAD were enrolled, and demographic information, clinical indicators, medication and blood flow reconstruction were collected. Patients were divided in three mutually exclusive categories by baseline pulse palpation heart rate(HR)≤60 beats per minute (bpm)(n=397), 61-69 bpm(n=782), and ≥70 bpm(n=1 443). The patients were also divided into taking BB or not taking BB groups. The aim of present study is to describe and analyze the current status and factors related to the HR control and BB use in the Chinese subgroup of CLARIFY.

RESULTS: A total of 2 622 patients were enrolled from 56 centers across China. The mean age was (63.6±10.3) years old with 75.6% (1 983) male patients, 55.0% (1 443) patients had HR≥70 bpm. Mean HR measure by electrocardiogram(ECG) was (69.4±10.2)bpm, 50.9% (1 334 cases) patients had myocardial infarction(MI) history. A total of 21.9%(575 cases) patients had anginal symptoms; coronary angiography was performed in 88.8%(2 327 cases) of the patients. 76.2%(1 997 cases) patients were treated with BB (any molecule and any dose), 2.7% (70 cases) with digoxin or derivatives, 3.9% (103 cases) with verapamil or diltiazem, and 1.8% (47 cases) with amiodarone or dronedarone and 0.1%(2 cases) received ivabradine. BB use was similar among 3 HR groups(P>0.05). The independent risk factors associated with HR≥70 bpm were diabetes(OR=1.31), current smoker(OR=1.57), chronic heart failure(CHF) with NYHA Ⅲ (OR=2.13) and increased diastolic blood pressure (OR=1.30). Conversely, high physical activity (OR=0.61), former smoker (OR=0.76) and history of percutaneous coronary intervention(PCI, OR=0.80) were associated with lower risk of HR≥70 bpm (all P<0.05). The independent risk factors associated with non-BB use were older age (OR=1.11, 95%CI 1.01-1.47, P=0.005), lower diastolic blood pressure (OR=1.47, 95%CI 1.32-1.68, P=0.012), no history of MI (OR=1.86, 95%CI 1.43-2.44, P<0.001) or PCI (OR=1.94, 95%CI 1.55-3.73, P<0.001), asthma/chronic obstructive pulmonary disease (OR=1.32, 95%CI 1.15-1.99, P<0.001).

CONCLUSIONS: A total of 76.2% Chinese SCAD patients received BB medication but more than half of them did not reach the optimal HR. Clinical characteristics including diabetes, current smoker, CHF, increased diastolic blood pressure and no PCI were associated with poorly controlled HR(≥70 bpm). More efforts including adjusting the type and dose of heart rate lowering drugs are needed to achieve optimal HR control in Chinese SCAD patients. Clinical Trail Registry International Standard Randomized Controlled Trial, ISRCTN43070564.