Early and midterm outcome after off-pump and on-pump surgery in Beating Heart Against Cardioplegic Arrest Studies (BHACAS 1 and 2): a pooled analysis of two randomised controlled trials. - BHACAS

Description:

The BHACAS trials were two randomized trials designed to compare the short-term morbidity associated with off-pump and on-pump myocardial revascularization. In this meta-analalysis data were pooled from both trials to assess midterm outcomes.

Hypothesis:

Off-pump surgery would be associated would be associated with improved in-hospital outcomes and midterm outcomes compared with conventional on-pump coronary surgery.

Study Design

Study Design:

Patients Enrolled: 401

Patient Populations:

Patients with severe coronary artery disease and considered appropriate surgical candidates for bypass surgery.

Exclusions:

For BHACAS 1, patients were excluded if they had a left-ventricular ejection fraction of less than 30%, recent myocardial infarction within 1 month, a history of supraventricular arrhythmia, previous CABG, renal or respiratory impairment or previous stroke, transient ischaemic attack, or coagulopathy. Patients with coronary disease in the branches of the circumflex artery distal to the first obtuse marginal branch were also excluded; such patients, and those with recent myocardial infarction, were not excluded from BHACAS 2.

Primary Endpoints:

All-cause mortality or a cardiac-related event at midterm follow-up (ie, 1–3 years after surgery), although each of the trials was designed to investigate short-term morbidity and health-care use.

Secondary Endpoints:

Cardiac-related events, including need for a further coronary revascularization or coronary angiography, myocardial infarction, congestive heart failure, arrhythmia, or recurrence of angina.

Drug/Procedures Used:

After obtaining informed consent, patients were randomly allocated to myocardial revascularisation with either on-pump surgery with cardiopulmonary bypass and cardioplegic arrest at normal temperatures, or off-pump surgery on the beating heart.

Principal Findings:

A total of 401 were evaluated. 200 eligible patients were randomized to on-pump (n=100) and off-pump surgery (n=100) for BHACAS 1 and 201 patients were randomized to on-pump (n=101) and off-pump surgery (n=100) for BHACAS 2. Baseline characteristics were comparable among groups. Pooling of data from both trials showed that risk of in-hospital morbidity (within 30 days of surgery) was lower in patients who had off-pump than in those who had on-pump surgery for transfusion of packed blood cells (-31%, 95% CI -41 to -21) and fresh frozen plasma (-15%, 95% CI -21 to -9), intubation time longer than 10 h (-16%, 95% CI -25 to -6), intensive-care unit stay for longer than 1 day (-13%, 95% CI -25 to -6), and total hospital stay longer than 7 days(-13%, 95% CI -21 to -5). Pooled survival estimates at 24 months were 96% (95% CI 91–98) and 97% (92–99) for on-pump and off-pump groups, respectively. No cardiac event differed in frequency between groups. Myocardial infarction was diagnosed in 4% of patients in the on-pump groups and in four 2% in the off-pump groups. Recurrent angina was recorded in 14% of patients in the on-pump groups and in 12% of patients in the off-pump groups. The hazard ratio for all cause mortality or cardiac related events was 0.78 (95% CI 0.49–1.22) for off-pump compared with on-pump surgery for both trials combined. Pooled estimates for survival free from any cardiac-related event at 24 months were 78% (71–84) and 84% (78–89) for on-pump and off-pump groups. After pooling data for BHACAS 1 and 2, no significant differences were recorded in the pooled frequencies of any non cardiac-related events between on-pump and off-pump groups.

Interpretation:

The results of the BHACAS 1 and 2 trials confirmed that in-hospital morbidity was lower in patients who had off-pump surgery than in those who underwent conventional on-pump coronary revascularization and that off-pump coronary surgery significantly reduces in-hospital morbidity without compromising midterm outcome compared with conventional on-pump coronary surgery.

References:

Early and midterm outcome after off-pump and on-pump surgery in Beating Heart Against Cardioplegic Arrest Studies (BHACAS 1 and 2): a pooled analysis of two randomised controlled trials. Gianni D Angelini, Fiona C Taylor, Barnaby C Reeves and Raimondo Ascione. Lancet 2002;359(9313):1194-1199

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention

Keywords: Myocardial Infarction, Intubation, Coronary Artery Bypass, Off-Pump, Cardiopulmonary Bypass, Coronary Artery Bypass


< Back to Listings