title: Preoperative intra-aortic counterpulsation in high-risk patients undergoing cardiac surgery: a meta-analysis of randomized controlled trials†.
abstract: In contrast to the results of previous studies, recent randomized controlled trials (RCTs) failed to show a benefit of prophylactic aortic counterpulsation in high-risk patients undergoing cardiac surgery. The present analysis aims to redefine the effects of this treatment modality in the light of this new evidence. MEDLINE, EMBASE, CENTRAL/CCTR, Google Scholar and reference lists of relevant articles were searched for full-text articles of RCTs in English or German. Assessments for eligibility, relevance, study validity and data extraction were performed by two reviewers independently using prespecified criteria. The primary outcome was hospital mortality. A total of nine eligible RCTs with 1171 patients were identified: 577 patients were treated preoperatively with intra-aortic balloon pump (IABP) and 594 patients served as controls. The pooled odds ratio (OR) for hospital mortality (22 hospital deaths in the intervention arm, 54 in the control group) was 0.381 (95% CI 0.230-0.629; P < 0.001). The pooled analyses of five RCTs including only patients undergoing isolated on-pump coronary artery bypass grafting (n[IABP] = 348, n[control] = 347) also showed a statistically significant improvement in mortality for preoperative IABP implantation (fixed-effects model: OR 0.267, 95% CI 0.129-0.552, P < 0.001). The pooled OR for hospital mortality from two randomized off-pump trials was 0.556 (fixed-effects model, 95% CI 0.207-1.493, P = 0.226). Preoperative aortic counterpulsation was associated with a significant reduction in low cardiac output syndrome (LCOS) in the total population (fixed-effects model: OR 0.330, 95% CI 0.214-0.508, P < 0.001) as well as in the subgroup of CAGB patients (fixed-effects model: OR 0.113, 95% CI 0.056-0.226, P < 0.001), whereas there was no benefit in the off-pump population (fixed-effects model: OR 0.555, 95% CI 0.209-1.474, P = 0.238). Preoperative IABP implantation was associated with a reduction of intensive care unit (ICU) stay in all investigated populations with a greater effect in the total population [fixed-effects model: standard mean difference (SMD) -0.931 ± 0.198, P < 0.001] as well as in the subgroup of CAGB patients (fixed-effects model: SMD -1.240 ± 0.156, P < 0.001), compared with the off-pump group (fixed-effects model: SMD -0.723 ± 0.128, P < 0.001). Despite contradictory results from recent trials, the present study confirms the findings of previous meta-analyses that prophylactic aortic counterpulsation reduces hospital mortality, incidence of LCOS and ICU requirement in high-risk patients undergoing on-pump cardiac surgery. However, owing to small sample sizes and the lack of a clear-cut definition of high-risk patients, an adequately powered, prospective RCT is necessary to find a definite answer to the question, if certain groups of patients undergoing cardiac surgery benefit from a prophylactic IABP insertion.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, West German Heart Centre Essen, University Hospital Essen, Essen Germany kevin.pilarczyk@uk-essen.de.
authors.forename: Kevin
authors.initials: K
authors.lastname: Pilarczyk
authors.affiliation: Department of Cardiovascular Surgery, Justus-Liebig University Gießen, Giessen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Boening
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, West German Heart Centre Essen, University Hospital Essen, Essen Germany.
authors.forename: Heinz
authors.initials: H
authors.lastname: Jakob
authors.affiliation: Department of Cardiothoracic Surgery, Cologne University Heart Centre, Cologne, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Langebartels
authors.affiliation: Department of Cardiovascular Surgery, Bundeswehr Central Hospital, Koblenz, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Markewitz
authors.affiliation: Department of Cardiovascular Surgery, School of Medicine, University of Schleswig-Holstein, Kiel, Germany.
authors.forename: Nils
authors.initials: N
authors.lastname: Haake
authors.affiliation: Department of Anesthesiology, University of Lübeck, Lübeck, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Heringlake
authors.affiliation: Department of Cardiovascular Surgery, Heart Center Freiburg University, Freiburg, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Trummer
mesh_terms: D006348:Cardiac Surgical Procedures / Q000379:methods* / Q000401:mortality*; D002315:Cardiopulmonary Bypass / Q000379:methods / Q000401:mortality; D003131:Combined Modality Therapy; D001026:Coronary Artery Bypass / Q000379:methods / Q000401:mortality; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D007423:Intra-Aortic Balloon Pumping / Q000379:methods*; D007902:Length of Stay; D008297:Male; D011300:Preoperative Care / Q000379:methods; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment; D012720:Severity of Illness Index; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: Cardiac surgery; High-risk patients; Intra-aortic balloon pump; Prophylactic counterpulsation