The effectiveness of intra-aortic balloon pump for myocardial infarction in patients with or without cardiogenic shock: a meta-analysis and systematic review

Zheng et al. BMC Cardiovascular Disorders (2016) 16:148 DOI 10.1186/s12872-016-0323-2 RESEARCH ARTICLE Open Access The effectiveness of intra-aortic balloon pump for myocardial infarction in patients with or without cardiogenic shock: a meta-analysis and systematic review Xiao-yun Zheng*, Yi Wang, Yi Chen, Xi Wang, Lei Chen, Jun Li and Zhi-gang Zheng Abstract Background: Conflicting reports on the efficacy of intra-aortic balloon pump (IABP) during percutaneous coronary intervention (PCI) incited us to evaluate the utility of IABP in patients with acute myocardial infarction (AMI). Methods: Randomized clinical trials comparing patients, who received IABP vs. control (no IABP) during PCI, were hand-searched from MEDLINE, Cochrane, and EMBASE databases using the terms “intra-aortic balloon pump, percutaneous coronary intervention, myocardial infarction, acute coronary syndrome”. Mortality rate (30-day and 6-month mortality) was the primary outcome, while the secondary outcomes included 30-day bleeding rate, reinfarction rate, revascularization rate and stroke rate. Results: Pooled results of the seven trials identified indicated that the 30-day and 6-month mortality rate were not significantly different between the IABP and control groups. However, in patients with MI, but without cardiogenic shock (CS), IABP was associated with lower odds of 30-day mortality (OR = 0.35, p = 0.015) and 6-month mortality (OR = 0.41, p = 0.020). The pooled results of 30-day bleeding rate was not significantly higher in patients with IABP than the control group, but for the patients with high risk PCI without CS, it was higher in patients with IABP than the control group (OR = 1.58, p = 0.009). The re-infarction, revascularization, and the stroke rate at 30 days of follow-up were not significantly different between the two groups. Conclusions: The present results do not favor the clinical utility of IABP in patients suffering high-risk PCI without CS and AMI complicated with CS. However, in patients with AMI, but without CS, IABP may reduce the 30-day and 6-month mortality rate. Keywords: Myocardial infarction, Percutaneous coronary intervention, Intra-aortic balloon pump Background Acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) is one of the leading causes of death in patients hospitalized with AMI, and it accounts for 41.1 % of overall in-hospital mortality in a populationbased study [1, 2]. Intra-aortic balloon pump (IABP) is the most widely used mechanical device for the treatment of AMI [3, 4], since its introduction by Kantrowitz and colleagues in early 1960s [5]. The International Benchmark Registry (250 US and non-US centers) of * Correspondence: Department of Senior Official Ward, China-Japan Friendship Hospital, 2 Yinghua Dongjie, Beijing 100029, China 22,633 AMI patients treated with IABP suggested that 19 % of IABP implantation were for cardiogenic shock, 19.9 % for angiography and angioplasty, and 14.6 % as an adjunct (pre-operative) to high-risk coronary artery bypass grafting [6]. IABP support effectively reduces the left ventricular wall stress and myocardial demand, increases the coronary perfusion pressure, stroke volume, cardiac output, and ameliorates ischemia, making it a potentially valuable therapy in CS [3, 7, 8]. Reports elsewhere suggest that IABP offers a substantial advantage when used in combination with thrombolytic therapy [9, 10]. In a previous study, the use of IABP in conjunction with thrombolytic therapy decreased the odds of © 2016 The Author(s). Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Zheng et al. BMC Cardiovascular Disorders (2016) 16:148 death by 18 % [9]. In addition, IABP has been widely used in the prevention of adverse catheter laboratory events during elective high-risk PCI [11]. Despite its frequent use in the clinical practice for the treatment of AMI, recent reports dispute whether intraaortic balloon counterpulsation provide any incremental benefit to reperfusion therapy [9, 10, 12, 13]. In patients with AMI and CS, the evidence in favor of IABP is currently limited to registry data and retrospective analyses, and small, prospective studies without any reliable mortality data [14]. A recent systematic review and metaanalysis comparing IABP versus no IABP in patients with AMI and CS concluded that the available data did not provide a convincing evidence for either benefit or harm to support the use of IABP counterpulsation [8]. According to the 2011 guidelines released by the American College of Cardiology Foundation (ACCF) and American Heart Association (AHA), IABP counterpulsation is reasonable in non-ST-elevation myocardial infarction (NSTEMI) patients for severe ischemia that is continuing or recurs frequently despite medical therapy, for hemodynamic instability in patients before or after coronary angiography, and for mechanical complications of MI [15]. In 2013, ACCF/AHA has released an updated guideline for patients with STEMI, where the recommendation for the placement of IABP in CS was downgraded from Class I to Class IIa, because of the lack of clear superiority in clinical benefit and reduction of mortality [16, 17]. Similarly, IABP was recommended in ST-elevation myocardial infarction (STEMI) patients with CS by the European Society of Cardiology in 2008 but an updated guideline released by European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS) in 2014 did not recommend routinely using IABP in patients with CS [18, 19]. Use of elective IABP support in patients undergoing high-risk PCI is still debatable. The evidence suggests that routine IABP use does not provide clinical benefit in patients undergoing high-risk procedures or those with AMI in the absence of CS, but it causes a relative reduction in the long-term all-cause mortality [11]. Bahekar and colleagues also indicated that while IABP is not beneficial in high-risk AMI patients without cardiogenic shock, there was significant reduction in mortality with IABP in patients having AMI with cardiogenic shock [20]. Considering the contrasting reports in the field and the necessity for unified guidelines for the use of IABP, it is of utmost importance to evaluate the clinical relevance of IABP as an adjunct therapy to PCI in patients with acute myocardial infarction with or without CS. The present meta-analysis evaluated the clinical outcomes of IABP as an adjunc (...truncated)