Prophylactic value of preincision intra-aortic balloon pump: analysis of a statewide experience

Alternate Approach to Concomitant Carotid and Coronary Disease: Perioperative IABP Use during Carotid Endarterectomy

BACKGROUND

Demographics are shifting toward an increasingly older population in the United States; thus, it is imperative that patients with a complex cardiovascular history are approached in a systematic fashion. Currently, there is no clear protocol on how best to manage elderly patients who present with both severe coronary artery disease and symptomatic carotid stenosis. For cardiac patients with severe, asymptomatic, high-grade carotid artery stenosis, there may be even more of a conundrum. Although most centers would tend to manage the asymptomatic carotid stenosis expectantly, it is well known that patients with severe, uncorrected internal carotid artery disease are at an increased risk of experiencing a cerebrovascular accident during coronary artery bypass grafting (CABG). One approach that has been recognized in other settings as a cost-effective strategy to stabilize high-risk elderly patients preoperatively is the use of an intra-aortic balloon pump (IABP). To better understand the best approach to take in these patients with concomitant disease, we analyzed the outcomes of 4 patients who underwent placement of an IABP before carotid endarterectomy (CEA) as a bridge to CABG.

METHODS

Between 2017 and 2019, 4 patients presented with multivessel symptomatic coronary artery disease and greater than 90% stenosis of at least one internal carotid artery and underwent either staged or simultaneous CEA and CABG. There was placement of an IABP in all patients before the CEA. Time to CABG ranged from a simultaneous procedure to 23 days after CEA.

RESULTS

The only death within 30-day postoperation involved the patient who had CEA and CABG performed simultaneously. None of the surviving patients experienced a myocardial infarction. Two of the 4 patients experienced acute kidney injury after surgery, and one patient developed atrial fibrillation postoperatively. None of the patients experienced a postoperative neurological complication. In addition, there were no access site complications associated with IABP placement.

CONCLUSIONS

A staged procedure with placement of an IABP can be successfully used in carefully selected patients presenting with concomitant severe carotid and coronary artery disease who will undergo surgical management of their disease. The stabilization provided by IABP was potentially protective against adverse postoperative events and appeared to allow for flexibility in the time between CEA to CABG for patients. Additional studies are necessary to further understand the impact of such an approach.

Preoperative Intra-Aortic Balloon Pumps in Cardiac Surgery: A Propensity Score Analysis

INTRODUCTION

The role of intra-aortic balloon pumps (IABP) in high-risk patients undergoing coronary artery bypass graft (CABG) surgery remains controversial. We report the 5-year experience from a new Australian centre.

METHODS

We retrospectively analysed 690 patients undergoing urgent isolated CABG surgery at a Western Australian tertiary centre from February 2015 to May 2020. De-identified data was obtained from the Australia & New Zealand Society of Cardiothoracic Surgeons database. Patients were stratified according to preoperative IABP use. A propensity score was created for the probability of IABP use and a propensity adjusted analysis was performed using logistic regression. The primary outcome was 30-day mortality. Secondary outcomes were postoperative inhospital outcomes.

RESULTS

Preoperative IABP was used in 78 patients (11.3%). After propensity score adjustment, in a subgroup of patients with reduced ejection fraction or left main disease, 30-day mortality (7.0% vs 2.0%, OR 6.03, 95% CI 1.89-19.28, p=0.002) was significantly higher in the IABP group. Red blood cell transfusions (19.7% vs 12.6%, OR 1.86, 95% CI 1.02-3.35, p=0.039), prolonged inotrope use (78.9% vs 50.9%, OR 6.11, 95% CI 2.77-13.48, p<0.001), prolonged invasive ventilation (28.2% vs 3.4%, OR 20.2, 95% CI 8.24-49.74, p<0.001), mesenteric ischaemia (2.8% vs 0%, OR 4.52, 95% CI 1.15-17.77, p=0.031) and multisystem organ failure (1.3% vs 0.7%, OR 25.68, 95% CI 2.55-258.34, p=0.006) were significantly higher in the IABP group.

CONCLUSION

In patients undergoing isolated CABG surgery, preoperative IABP use was associated with increased 30-day mortality and adverse outcomes. Large randomised controlled trials are required to confirm our findings.

Prophylactic intra-aortic balloon pump in patients with left main disease undergoing off-pump coronary artery bypass grafting

Background

Preventive intra-aortic balloon pump (IABP) for high-risk patients with stable hemodynamics is controversial, and its definition of high-risk is still unclear. This study aimed to investigate the effect of prophylactic IABP on the early outcome of left main disease (LMD) patients receiving off-pump coronary artery bypass grafting (OPCABG) with stable hemodynamics.

Methods

From January 2013 to April 2020, 257 consecutive patients who underwent OPCABG through sternotomy were enrolled in this study. All LMD patients (greater than 70%) had stable hemodynamics (BP>100 mmHg without vasoconstrictor substance infusion). Early outcomes of 125 patients with prophylactic IABP (IABP group) and 132 patients without IABP (Control group) were compared in this study.

Results

IABP did not show favorable effect on the conversion to CPB (RR 0.63, 95%CI 0.05–7.89, P = 0.7211), perioperative MI (RR 0.69, 95%CI 0.22–2.12, P = 0.5163), mortality (RR 0.65, 95%CI 0.04–10.25, P = 0.7608) or the composite end of the conversion, MI and mortality (RR 0.63, 95%CI 0.23–1.74, P = 0.3747). There was greater incidence of prolonged ventilation in IABP after adjustment (RR2.16, 95%CI 1.12–4.18, P = 0.0221). There was no IABP-related mortality or limb ischemia.

Conclusion

No significant difference in early outcomes was observed in hemodynamically stable patients with LMD between prophylactic IABP group and control group. Prophylactic IABP may be unnecessary in patients with LMD undergoing OPCABG.

Intra-aortic balloon pump postcardiac surgery: A literature review

Intra-aortic balloon pump (IABP) has been the most commonly used mechanical assist circulatory device in many postcardiotomy low output disorders for decades. Mechanism of IABP is based on its inflation in time of the diastolic pressure in the aortic root resulting increase in the blood and oxygen amount of the coronary artery and its deflation in left ventricular afterload during the systolic period. Prophylactic and postoperative application of IABP has been suggested by researchers, which has been commonly used in high-risk patients undertaking coronary artery bypass grafting surgery or percutaneous coronary intervention. Other researchers put forward the idea of the percutaneous IABP insertion throughout the left axillary artery as a reliable and relatively well-tolerated approach and also as a recovery tool to bridge patients with end-stage heart failure to heart transplantation. The current review was aimed to give further insight into routine IABP application by presenting the basic principles and trends in the incidence, management, role of IABP recovery, and long-lasting mortality outcomes in patients with cardiovascular disorders and discussing previous and current evidence.

Intra-aortic balloon pump: current evidence & future perspectives

The intra-aortic balloon pump (IABP) is frequently used to support severely compromised ventricles in critically ill patients. Its relatively affordability and ease of insertion has cemented its position as the first line of treatment for hemodynamic support in cardiogenic shock. Accordingly, the current ACC/AHA recommendations maintain a Class 2A for the use of IABP in shock. However, a review of the current literature suggests that the evidence supporting the American College of Cardiology and American Heart Association (ACC/AHA) guidelines are equivocal. Alternative uses for IABP such as perioperative support during high-risk cardiac surgery, treatment of left ventricular distention on extracorporeal membrane oxygenation, and as bridge to transplant have been proposed. The effectiveness of the IABP in these clinical situations remains largely unproven, due to the paucity of available data.

Preoperative intraaortic balloon pump before urgent coronary bypass grafting

Background Urgent or emergency coronary artery bypass grafting in patients with acute coronary syndrome is associated with increased morbidity and mortality. We investigated the effects of preoperative intraaortic balloon pump support in this high-risk patient cohort. Methods Our institutional database was retrospectively reviewed for patients with acute coronary syndrome and an urgent or emergency indication for coronary artery bypass from April 2010 to December 2016. Data of 1066 patients were analyzed. We assessed the impact of preoperative intraaortic balloon pump therapy on postoperative mortality and major adverse cardiovascular and cerebrovascular events, and performed propensity-score matching. Results Intraaortic balloon pump support was implemented in 223 (20.9%) patients: 55 (5.2%) preoperatively and 168 (15.8%) intra- or postoperatively. Overall hospital mortality was 8.8%. Patients with a preoperative intraaortic balloon pump had increased mortality (11/55, 20%) compared to controls ( p = 0.006). After propensity-score matching, all-cause mortality (20.0% vs. 18.2%, p = 0.834), cardiac mortality (18.2% vs. 14.5%, p = 0.651), and major adverse cardiovascular and cerebrovascular events (29.1% vs. 27.3%, p = 0.855) were comparable between groups. Conclusions Preoperative intraaortic balloon pump support does not confer any additional clinical benefit on patients undergoing coronary artery bypass grafting for acute coronary syndrome.

Clinical application of intra-aortic balloon counterpulsation in high-risk patients undergoing cardiac surgery

The intra-aortic balloon pump (IABP) has been the most commonly used mechanical circulatory support device for nearly five decades. In theory, the IABP can increase the blood and oxygen supply of the coronary artery by increasing the diastolic pressure in the aortic root when the balloon is inflated and reduce left ventricular afterload by rapidly deflating the balloon during the systolic phase. Therefore, some researchers put forward the idea of preoperative prophylactic use of an IABP, which has been frequently performed in high-risk patients undergoing elective percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG). Previous studies have suggested preoperative IABP has a controversial effect on patients undergoing revascularization; the role of preoperative IABP insertion in those patients undergoing CABG alone remains uncertain. This review will give further insight into routine IABP use by presenting the basic principles and discussing current evidence.

Levosimendan in patients with left ventricular systolic dysfunction undergoing cardiac surgery on cardiopulmonary bypass: Rationale and study design of the Levosimendan in Patients with Left Ventricular Systolic Dysfunction Undergoing Cardiac Surgery Requiring Cardiopulmonary Bypass (LEVO-CTS) trial

BACKGROUND

Low cardiac output syndrome is associated with increased mortality and occurs in 3% to 14% of patients undergoing cardiac surgery on cardiopulmonary bypass (CPB). Levosimendan, a novel calcium sensitizer and K_ATP channel activator with inotropic, vasodilatory, and cardioprotective properties, has shown significant promise in reducing the incidence of low cardiac output syndrome and related adverse outcomes in patients undergoing cardiac surgery on CPB.

METHODS

LEVO-CTS is a phase 3 randomized, controlled, multicenter study evaluating the efficacy, safety, and cost-effectiveness of levosimendan in reducing morbidity and mortality in high-risk patients with reduced left ventricular ejection fraction (≤35%) undergoing cardiac surgery on CPB. Patients will be randomly assigned to receive either intravenous levosimendan (0.2 μg kg^-1 min^-1 for the first hour followed by 0.1 μg/kg for 23hours) or matching placebo initiated within 8hours of surgery. The co-primary end points are (1) the composite of death or renal replacement therapy through day 30 or perioperative myocardial infarction, or mechanical assist device use through day 5 (quad end point tested at α<.01), and (2) the composite of death through postoperative day 30 or mechanical assist device use through day 5 (dual end point tested at α<.04). Safety end points include new atrial fibrillation and death through 90days. In addition, an economic analysis will address the cost-effectiveness of levosimendan compared with placebo in high-risk patients undergoing cardiac surgery on CPB. Approximately 880 patients will be enrolled at approximately 60 sites in the United States and Canada between July 2014 and September 2016, with results anticipated in January 2017.

CONCLUSION

LEVO-CTS, a large randomized multicenter clinical trial, will evaluate the efficacy, safety, and cost-effectiveness of levosimendan in reducing adverse outcomes in high-risk patients undergoing cardiac surgery on CPB.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT02025621).

Agreement of treatment effects for mortality from routinely collected data and subsequent randomized trials: meta-epidemiological survey

OBJECTIVE

To assess differences in estimated treatment effects for mortality between observational studies with routinely collected health data (RCD; that are published before trials are available) and subsequent evidence from randomized controlled trials on the same clinical question.

DESIGN

Meta-epidemiological survey.

DATA SOURCES

PubMed searched up to November 2014.

METHODS

Eligible RCD studies were published up to 2010 that used propensity scores to address confounding bias and reported comparative effects of interventions for mortality. The analysis included only RCD studies conducted before any trial was published on the same topic. The direction of treatment effects, confidence intervals, and effect sizes (odds ratios) were compared between RCD studies and randomized controlled trials. The relative odds ratio (that is, the summary odds ratio of trial(s) divided by the RCD study estimate) and the summary relative odds ratio were calculated across all pairs of RCD studies and trials. A summary relative odds ratio greater than one indicates that RCD studies gave more favorable mortality results.

RESULTS

The evaluation included 16 eligible RCD studies, and 36 subsequent published randomized controlled trials investigating the same clinical questions (with 17,275 patients and 835 deaths). Trials were published a median of three years after the corresponding RCD study. For five (31%) of the 16 clinical questions, the direction of treatment effects differed between RCD studies and trials. Confidence intervals in nine (56%) RCD studies did not include the RCT effect estimate. Overall, RCD studies showed significantly more favorable mortality estimates by 31% than subsequent trials (summary relative odds ratio 1.31 (95% confidence interval 1.03 to 1.65; I(2)=0%)).

CONCLUSIONS

Studies of routinely collected health data could give different answers from subsequent randomized controlled trials on the same clinical questions, and may substantially overestimate treatment effects. Caution is needed to prevent misguided clinical decision making.

Analysis of clinical outcomes of intra-aortic balloon pump use during coronary artery bypass surgery

AIM

The mortality rate of coronary artery bypass surgery increases with advanced patient age. This intra-aortic balloon pump (IABP) study was conducted to compare older patients (above 65 years of age) with younger patients (below 65 years of age) who had undergone coronary artery bypass surgery and had had an IABP inserted, with regard to hospital stay, clinical features, intensive care unit stay, postoperative complications, and mortality and morbidity rates.

METHODS

One hundred and ninety patients who had undergone coronary artery bypass surgery and had required IABP support were enrolled in this study. Patients younger than 65 years of age were considered younger, and the others were considered older. Ninety-two patients were in younger group and 98 patients were older group. The mortality rates, pre-operative clinical characteristics, postoperative complications, and duration of intensive care unit and hospital stay of the groups were compared. The risk factors for mortality and complications were analysed.

RESULTS

One hundred and thirty-eight of the patients were male, and the mean age was 62.7 ± 9.9 years. The mortality rate was higher in the older patient group than the younger group [34 (37.7%) and 23 (23.4 %), respectively (p = 0.043) ]. The crossclamp time, mean ejection fraction, cardiopulmonary bypass time, and length of stay in the intensive care unit were similar between the two groups (p > 0.05). Cardiopulmonary bypass time was the unique independent risk factor for mortality in both groups.

CONCLUSION

In this study, high mortality rates in the postoperative period were similar to those in prior studies regarding IABP support. The complication rates were higher in the older patient group. Prolonged cardiopulmonary bypass time and advanced age were determined to be significant risk factors for mortality.

Prophylactic Intra-Aortic Balloon Pump Before Ventricular Assist Device Implantation Reduces Perioperative Medical Expenses and Improves Postoperative Clinical Course in INTERMACS Profile 2 Patients

BACKGROUND

Although intra-aortic balloon pump (IABP) is sometimes used before cardiac surgery to achieve better outcome in high-risk patients, the clinical impact of prophylactic IABP support before left ventricular assist device (LVAD) implantation in patients with worsening hemodynamics was unknown.

METHODS AND RESULTS

We enrolled 22 patients with worsening hemodynamics who had received IABP support before LVAD (IABP group), and also enrolled 22 patients receiving neither IABP nor extracorporeal membrane oxygenation before LVAD, who were selected on propensity score matching (non-IABP group). Although both groups had similar preoperative background, the IABP group had shorter postoperative intensive care unit (ICU) stay, and more improved hemodynamics (P<0.05 for all). Serum total bilirubin and creatinine decreased significantly in the IABP group compared with the non-IABP group during 1 month after LVAD implantation (P<0.05 for both). Medical expenses during perioperative ICU stay were significantly lower in the IABP group compared with the non-IABP group, even including the cost of preoperative IABP support (P<0.05).

CONCLUSIONS

Prophylactic IABP support in heart failure patients with worsening hemodynamics improves post-LVAD clinical course and reduces perioperative medical expenses.

Prophylactic application of an intra-aortic balloon pump in high-risk patients undergoing off-pump coronary artery bypass grafting

BACKGROUND

An intra-aortic balloon pump (IABP) is the most commonly used circulatory assist device in cardiac surgery. We hypothesized that prophylactic application of an IABP improves early clinical outcome of high-risk patients undergoing scheduled off-pump coronary artery bypass grafting (OPCABG).

METHODS

From January 2010 to December 2013, hemodynamically stable, high-risk patients undergoing scheduled OPCABG with preincision use of an IABP were recruited to the IABP group. Using the propensity score-matching method, every patient in the IABP group was matched with another patient (the control group) with a similar propensity score who received an IABP on an as-needed basis during or after OPCABG. Surgical mortality and major morbidity rates were compared between groups.

RESULTS

A total of 116 patient pairs were included in this study. In patients in the IABP group, postoperative low cardiac output and respiratory as well as renal failure were less frequent, intensive care unit stay was shorter, and surgical mortality was lower compared to patients in the control group. In multivariate logistic regression, timing of IABP implantation, as an independent risk factor, was associated with postoperative low cardiac output (OR=2.02, 95% CI 1.28-5.76), respiratory failure (OR=1.86, 95% CI 1.19-4.27), renal failure (OR=2.96, 95% CI 1.51-6.63) and surgical mortality (OR=2.45, 95% CI 1.42-6.07).

CONCLUSIONS

Prophylactic application of an IABP improves postoperative cardiac performance, reduces respiratory and renal complications, and consequently lowers surgical mortality in high-risk patients undergoing scheduled OPCABG.

Preventive use of intra-aortic balloon pump in patients undergoing high-risk coronary artery bypass grafting: a retrospective study

Background

Coronary artery bypass grafting (CABG) is an important therapeutic measure for CHD patients. The patients who score more than 12 EuroSCORE points cannot achieve good results because of their low cardiac output and delicate left ventricular function. Therefore, use of an intra-aortic balloon pump (IABP) is essential for coronary surgical patients in the peri-operative period. At present, there is no unified standard about when to insert an IABP. This study aimed to compare the short-term clinical outcomes of the IABP inserted in the preoperative condition with its use in the emergency condition for extremely high-risk patients.

Material/Methods

IABP support time, respirator support time, and ICU stay time were significantly shorter (all p<0.05) in the preoperative IABP group compared to the emergency IABP group, and the rates of low cardiac output syndrome (LCOS), acute myocardial infarction, and acute kidney injury in the preoperative group were also significantly lower in the preoperative IABP group (all p<0.05). There were no significant differences in IABP-related complications and the mortality (p=0.106) between two groups.

Results

Compared to the emergency IABP group, the IABP support time, respirator support time and ICU stay time were significantly lower in the preoperative IABP group (all p<0.05), and the rates of LCOS, acute myocardial infarction, and acute kidney injury in the preoperative group were also significantly lower (all p<0.05). There were no significant differences in IABP-related complications and the mortality (p=0.106) between the 2 groups.

Conclusions

For high-risk patients with CABG, preoperative IABP insertion is a safe and effective measure.

Efficacy of prophylactic intra-aortic balloon pump therapy in chronic heart failure patients undergoing cardiac surgery

This study investigated the efficacy of prophylactic intraoperative intra-aortic balloon pump (IABP) usage in chronic heart failure patients with severely reduced left ventricular function undergoing elective cardiac surgery. Between January 2008 and December 2012, 107 patients with severely reduced left ventricular ejection fraction (LVEF <35%) received prophylactic intraoperative IABP implantation during open-heart surgery. Surgical procedures performed were isolated coronary artery bypass grafting (CABG) in 35 patients (32.7%), aortic valve replacement in 12 (11.2%), mitral valve repair or replacement in 15 (14.0%), combined valve and CABG procedures in 27 (25.2%), and other surgical procedures in 18 (16.8%). Results and outcomes were compared with those in a propensity score-matched cohort of 107 patients who underwent cardiac surgery without intraoperative IABP implantation. Matching criteria were age, gender, LVEF, and surgical procedure. Duration of intensive care unit (ICU) stay, duration of hospital stay, and 30-day mortality were markers of outcome. In the IABP group, mean patient age was 69.1 ± 13.7 years; 66.4% (70) were male. All IABPs were placed intraoperatively. Mean duration of IABP application time was 42.4 ± 8.7 h. IABP-related complications occurred in five patients (4.7%), including one case of inguinal bleeding, one case of mesenteric ischemia, and ischemia of the lower limb in three patients. No stroke or major bleeding occurred during IABP support. Mean durations of ICU and hospital stay were 3.38 ± 2.15 days and 7.69 ± 2.02 days, respectively, in the IABP group, and 4.20 ± 3.14 days and 8.57 ± 3.26 days in the control group, showing statistically significant reductions in duration of ICU and hospital stay in the IABP group (ICU stay, P = 0.036; hospital stay, P = 0.015). Thirty-day survival rates were 92.5 and 94.4% in the IABP and control group, respectively, showing no statistically significant difference (P = 0.75). IABP usage in chronic heart failure patients with severely reduced LVEF undergoing cardiac surgery was safe and resulted in shorter ICU and hospital stay but did not influence 7- and 30-day survival rates.

Counterpulsation: a concept with a remarkable past, an established present and a challenging future

The intra-aortic balloon pump (IABP), which is the main representative of the counterpulsation technique, has been an invaluable tool in cardiologists' and cardiac surgeons' armamentarium for approximately half a century. The IABP confers a wide variety of vaguely understood effects on cardiac physiology and mechano-energetics. Although, the recommendations for its use are multiple, most are not substantially evidence-based. Indicatively, the results of recently performed prospective studies have put IABP's utility in the setting of post-infarction cardiogenic shock into question. However, the particular issue remains open to further research. IABP support in high-risk patients undergoing PCI is associated with favorable long-term clinical outcome. In cardiac surgery, the use of IABP in cases of peri-operative low-output syndrome, refractory angina or ischemia-related mechanical complications is a usual, but poorly justified strategy. Anecdotal cases of treatment of incessant ventricular arrhythmias, reversal of right ventricular dysfunction and partial myocardial recovery have also been reported with its use. Converging data demonstrate the potential of safe long-term IABP support as a bridge to decision making or a bridge to transplantation modality in patients with heart failure. The feasibility of IABP insertion via other than the femoral artery sites enhances this potential. Despite the fact that several other counterpulsation devices have been developed and tested overtime none has managed to substitute the IABP, which continues to be most frequently used mechanical assist device.

Long-term outcomes of coronary artery bypass grafting patients supported preoperatively with an intra-aortic balloon pump

OBJECTIVE

Most studies describing the outcome of coronary artery bypass grafting patients supported preoperatively with an intra-aortic balloon pump (IABP) have reported early results. The purpose of our study was to evaluate the early and long-term results.

METHODS

Of 2658 isolated coronary artery bypass grafting procedures performed from 1996 to 2001, 215 were supported preoperatively with an IABP. The indications for IABP insertion were cardiogenic shock in 18 (8.4%), acute evolving myocardial infarction in 38 (17.7%), clinical instability in 84 (39.1%), and critical coronary lesions in 75 (34.9%).

RESULTS

Operative mortality was 12.6%. The mortality of the cardiogenic shock patients was greater (22.2%; P=.174). Logistic regression analysis showed patient age (odds ratio, 1.057; 95% confidence interval, 1.010-1.108) and cardiopulmonary bypass (CPB) time (odds ratio, 1.020; 95% confidence interval, 1.008-1.031) were associated with increased operative mortality. An increased number of bypass grafts had a protective effect (odds ratio, 0.241; 95% confidence interval, 0.113-0.515). The actual early mortality was lower than the logistic EuroSCORE calculated mortality (12.6% vs 32.8%, P<.0001). The mean follow-up was 8±4 years. The Kaplan-Meier 10-year survival was 49%. The Cox adjusted overall (early and late) survival and major adverse cardiac events-free survival of the different IABP subgroups was similar. Cox analyses showed peripheral vascular disease, off-pump coronary artery bypass surgery, age, CPB time, female gender, and fewer bypass grafts were associated with decreased survival.

CONCLUSIONS

In patients supported preoperatively with an IABP, better early and long-term results were strongly related to younger age, a shorter CPB time, and a greater number of bypass grafts. Avoiding the use of CPB (off pump) in these emergency cases is not recommended.

Predictors of intra-aortic balloon pump insertion in coronary surgery and mid-term results

Background

We aimed to investigate the preoperative, operative, and postoperative factors affecting intra-aortic balloon pump (IABP) insertion in patients undergoing isolated on-pump coronary artery bypass grafting (CABG). We also investigated factors affecting morbidity, mortality, and survival in patients with IABP support.

Methods

Between January 2002 and December 2009, 1,657 patients underwent isolated CABG in İzmir Katip Celebi University Atatürk Training and Research Hospital. The number of patients requiring support with IABP was 134 (8.1%).

Results

In a multivariate logistic regression analysis, prolonged cardiopulmonary bypass time and prolonged operation time were independent predictive factors of IABP insertion. The postoperative mortality rate was 35.8% and 1% in patients with and without IABP support, respectively (p=0.000). Postoperative renal insufficiency, prolonged ventilatory support, and postoperative atrial fibrillation were independent predictive factors of postoperative mortality in patients with IABP support. The mean follow-up time was 38.55±22.70 months and 48.78±25.20 months in patients with and without IABP support, respectively. The follow-up mortality rate was 3% (n=4) and 5.3% (n=78) in patients with and without IABP support, respectively.

Conclusion

The patients with IABP support had a higher postoperative mortality rate and a longer length of intensive care unit and hospital stay. The mid-term survival was good for patients surviving the early postoperative period.

Overview of the 2012 Food and Drug Administration circulatory system devices panel meeting on the reclassification of external counterpulsation, intra-aortic balloon pump, and non-roller-type cardiopulmonary bypass blood pump devices

The Food and Drug Administration held a Circulatory System Devices Advisory Panel meeting, December 5 and 6, 2012, to review the classification or potential reclassification of the following device types: external counterpulsation, intra-aortic balloon pump (IABP), and non-roller-type cardiopulmonary bypass blood pumps. These 3 devices are preamendment (Medical Device Amendments of 1976) class III devices. The advisory panel discussed the data and provided recommendations for reclassification of these devices. The panel recommended reclassification of ECP to class II for stable angina pectoris and to retain a class III for all other indications. For IABP, the recommendation was to reclassify IABP to class II for several indications (acute coronary syndrome, cardiac and noncardiac surgery, and heart failure complications) and remain class III for all other indications. As for non-roller type, the panel recommended that for cardiopulmonary bypass and temporary circulatory bypass, these devices should be reclassified to class II while retaining a class III device status for all other indications, including ventricular support both for hemodynamically unstable patients and for prophylactic support in high-risk percutaneous interventions.

IABP before cardiac surgery: clinical benefit compared to intraoperative implantation

Background:

The aim of this study was to determine whether preoperative compared to intraoperative intra-aortic balloon counterpulsation (IABP) is advantageous regarding 30-day and 2-year survival in high-risk patients (acute myocardial infarction, severely impaired left ventricular ejection fraction (LVEF), low output syndrome) undergoing coronary surgery.

Methods:

In the years 2004 to 2008, 156 consecutive patients undergoing coronary surgery with IABP support (119 preoperative, 37 intraoperative IABP) were observed. Applying Fisher’s exact test, as well as Wilcoxon and median tests, possible group differences were evaluated. After univariate analysis, models of logistic regression and Cox-regression were built.

Results:

Preoperative hemodynamic state and risk profile of the two patient groups were comparable: patients with preoperative IABP showed a similar level of urgency (21.9% vs. 18.9% emergencies), cardiogenic shock (8.4% vs. 10.8%), inotropes (8.4% vs. 8.1%), impaired LVEF (30.3% vs. 29.7%) and ventilation (5.9% vs. 5.4%) compared to patients with intraoperative IABP. Nevertheless, patients with intraoperative IABP demonstrated a significantly higher 30-day mortality rate (37.8% vs. 5.9%) and 2-year mortality rate (54.0% vs. 18.1%) compared to patients with preoperative IABP. Logistic regression revealed that patients with intraoperative IABP have a 16-times higher 30-day mortality rate after coronary surgery (OR: 16.386, 95% CI: 4.858-55.266) than patients with preoperative IABP. Two-year mortality (OR: 9.317, 95% CI: 3.430 to 25.311) and survival time were significantly better in patients with preoperative IABP therapy.

Conclusion:

Considering the significant benefit for patients with preoperative compared to intraoperative IABP and the absence of vascular problems after IABP insertion, the results of this study indicate a more liberal indication for IABP in high-risk patients before coronary bypass surgery.

Intra-aortic balloon pump (ΙΑΒΡ): from the old trends and studies to the current "extended" indications of its use

This report outlines the well defined indications of using IABP and also favours extending the indications of IABP use, to include not only “therapeutically” the aging unstable patients but also “prophylactically” patients with low EF or high Euroscore.

Preoperative intra-aortic balloon pump in high-risk coronary bypass grafting

Prophylactic intra-aortic balloon pumping prior to coronary artery bypass grafting is employed variably despite some evidence to support its use. The aim of this study was to describe the characteristics, preoperative balloon pump utilization, and outcomes of high-risk patients undergoing coronary artery bypass. The study cohort included all patients in the Australian National Cardiac Surgery Database over an 8 year period. The primary outcome was 30-day mortality adjusted for preoperative illness severity. Coronary artery bypass was performed in 18,662 patients including 2,348 (12.6%) identified as high-risk. Of these high-risk patients, 359 (15.3%) received a balloon pump preoperatively. For high-risk patients, 30-day mortality was significantly higher in those with a preoperative balloon pump than in those who did not receive a preoperative balloon pump (15.3% vs. 4.9%). After adjusting for preoperative illness severity, there was no significant association between preoperative balloon pumping and 30-day mortality. High-risk patients represent a significant proportion of those undergoing coronary artery bypass grafting. Despite their increased risk of postoperative mortality, only a small minority currently receive a preoperative balloon pump. After adjusting for illness severity, there was no significant association between preoperative balloon pumping and 30-day mortality, although we could not rule out a 20% reduction in mortality.

Preoperative intra aortic balloon pumps in patients undergoing coronary artery bypass grafting

BACKGROUND

The intra aortic balloon pump (IABP) is a mechanical assist device which improves cardiac function. The device has a well-established place in algorithms for managing low cardiac output following cardiac surgery. There is increasing evidence that certain cardiac surgery patients benefit from a period of preoperative augmentation with the intra aortic balloon pump.

OBJECTIVES

To determine the effect of the preoperative intra aortic balloon pump on mortality and morbidity in a number of different patients groups undergoing coronary artery bypass grafting.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 3, 2009), MEDLINE (2000 to August 2009), EMBASE (1998 to August 2009), BIOSIS previews (1969 to August 2009) and ISI Proceedings (1990 to August 2009) were searched. References and ongoing registers of studies were checked. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of any size or length were included.

DATA COLLECTION AND ANALYSIS

Papers were assessed for inclusion by two authors independently and differences were settled by consensus with a third author. Date are presented in the form of odds ratios (OR) and 95% confidence intervals (CI).

MAIN RESULTS

Six trials were included (five on-pump and one off-pump). This update adds the results of one further trial. Data from a total of 255 patients were included in the meta-analysis of mortality outcomes; all on-pump. Generally, the patients were considered as "high risk" and 132 were treated preoperatively with IABP and 123 served as controls. There were four hospital deaths in the intervention arm and 23 in the non-intervention arm (OR 0.18, 95% CI 0.08 to 0.41; P<0.0001). In a subgroup analysis, low cardiac index (<2.0 L/min/m(2)) was noted in 21 out of 105 patients in the treatment arm and 59 patients out of 88 in the non-treatment arm (OR 0.14, 95% CI: 0.08 to 0.25; P<0.00001). An off-pump versus on-pump analysis was not possible due to the limited number of off-pump studies. However a single well-conducted RCT suggested favourable effect of the preoperative IABP in off-pump patients.

AUTHORS' CONCLUSIONS

Evidence suggests that preoperative IABP may have a beneficial effect on mortality and morbidity in specific high risk patient groups undergoing coronary artery bypass grafting, however there are many problems with the quality, validity and generalisability of the trials. However, the available evidence is not robust enough to extend the use of IABP to truly elective, high risk patients. Defining more precisely which patient groups may benefit would be the challenge for the future.

A clinical score to predict the need for intraaortic balloon pump in patients undergoing coronary artery bypass grafting

BACKGROUND

There is no accepted consensus on the definition of high-risk patients who may benefit from the use of intraaortic balloon pump (IABP) in coronary artery bypass grafting (CABG). The aim of this study was to develop a risk model to identify high-risk patients and predict the need for IABP insertion during CABG.

METHODS

From April 1996 to December 2006, 8,872 consecutive patients underwent isolated CABG; of these 182 patients (2.1%) received intraoperative or postoperative IABP. The scoring risk model was developed in 4,575 patients (derivation dataset) and validated on the remaining patients (validation dataset). Predictive accuracy was evaluated by the area under the receiver operating characteristic curve.

RESULTS

Mortality was 1% in the entire cohort and 18.7% (22 patients) in the group which received IABP. Multivariable analysis showed that age greater than 70 years, moderate and poor left ventricular dysfunction, previous cardiac surgery, emergency operation, left main disease, Canadian Cardiovascular Society 3-4 class, and recent myocardial infarction were independent risk factors for the need of IABP insertion. Three risk groups were identified. The observed probability of receiving IABP and mortality in the validation dataset was 36.4% and 10% in the high-risk group (score >14), 10.9% and 2.8% in the medium-risk group (score 7 to 13), and 1.7% and 0.7% in the low-risk group (score 0 to 6).

CONCLUSIONS

This simple clinical risk model based on preoperative clinical data can be used to identify high-risk patients who may benefit from elective insertion of IABP during CABG.

The need for intra aortic balloon pump support following open heart surgery: risk analysis and outcome

Background

The early and intermediate outcome of patients requiring intraaortic balloon pump (IABP) was studied in a cohort of 2697 adult cardiac surgical patients.

Methods

136 patients requiring IABP (5.04%) support analysed over a 4 year period. Prospective data collection, obtained.

Results

The overall operative mortality was 35.3%. The "operation specific" mortality was higher on the Valve population.

The mortality (%) as per time of balloon insertion was: Preoperative 18.2, Intraopeartive 33.3, postoperative 58.3 (p < 0.05).

The incremental risk factors for death were: Female gender (Odds Ratio (OR) = 3.87 with Confidence Intervals (CI) = 1.3-11.6), Smoking (OR = 4.88, CI = 1.23- 19.37), Preoperative Creatinine>120 (OR = 3.3, CI = 1.14-9.7), Cross Clamp time>80 min (OR = 4.16, CI = 1.73-9.98) and IABP insertion postoperatively (OR = 19.19, CI = 3.16-116.47).

The incremental risk factors for the development of complications were: Poor EF (OR = 3.16, CI = 0.87-11.52), Euroscore >7 (OR = 2.99, CI = 1.14-7.88), history of PVD (OR = 4.99, CI = 1.32-18.86).

The 5 years survival was 79.2% for the CABG population and 71.5% for the valve group. (Hazard ratio = 1.78, CI = 0.92-3.46).

Conclusions

IABP represents a safe option of supporting the failing heart. The need for IABP especially in a high risk Valve population is associated with early unfavourable outcome, however the positive mid term results further justify its use.

Transfer of patients dependent on an intra-aortic balloon pump using critical care services

INTRODUCTION

The intra-aortic balloon pump (IABP) is a hemodynamic support device that provides circulatory enhancement to patients whose cardiac output is compromised. Special clinical skills are required for management of the patient with an IABP in place. Few studies have discussed the transport of the IABP-dependent patient. The current study was designed to describe the transport of IABP-dependent patients, with a focus on pretransport interventions, transport interventions, quality improvement, and complications.

METHODS

A review of all transports from January 1, 2004, through December 31, 2005, performed by a critical care transport program with a nurse/paramedic crew offering mobile intensive care unit (ICU), rotor-wing, and fixed-wing service was conducted. All patients who were maintained on an intra-aortic balloon pump (IABP) were eligible for inclusion. A certified perfusionist was available for consultation on all transports. Information about the IABP, including the pump timing, confirmation of balloon location, and inflation/deflation timing parameters, was collected. Proper balloon placement was verified and recorded at the sending hospital. Data were collected regarding interventions required before and during transport and complications during transport. Descriptive statistics were used.

RESULTS

During the study period, 173 transports involving an IABP were performed. The average age was 60.8 years, and 67.8% were men. Forty-one percent were flown by rotor-wing, 36.4% were transported by the mobile ICU, and 21.4% were flown by the fixed-wing transport. In 1.2% of cases, there was a change in transport mode. Twelve percent of patients required some increase in oxygen supplementation, but only one patient required intubation before transport by the transport crew. The most common pretransport medications were heparin (69%), inotropes (55%), and other infusions (46.8%). Twenty-two percent had no written confirmation of the correct balloon placement. There were no significant complications found during transport, including hemorrhage, loss of trigger signals, or cardiac arrest. Twelve percent had some abnormalities in timing of balloon inflation or deflation.

CONCLUSION

IABP transports can be safely performed by a nurse/paramedic critical care transport team with perfusionist consultation. Few patients require significant intervention before transport. Attention must be paid to balloon inflation and deflation timing despite the existence of timing algorithms. Significant complications during transport were not seen. Future studies should explore the overall outcome of IABP-dependent patients and the role of transport mode on outcome.

Efficacy of Elective Intra-aortic Balloon Pump Therapy for High-Risk Off-Pump Coronary Artery Bypass: A Prospective Comparative Study

OBJECTIVE

This study evaluated the usefulness of elective intra-aortic balloon pumping (IABP) in high-risk off-pump coronary artery bypass grafting (OPCAB).

MATERIALS AND METHODS

From October 2002 through September 2006, total of 143 patients were operated with OPCAB. These patients were divided into two groups and clinical outcomes were compared: Group E (N = 30): Elective IABP group and Group C (N = 113): Control group, OPCAB without IABP. The criteria of elective application of IABP were severe stenosis of left main coronary artery (LMCA) or left ventricular dysfunction with an ejection fraction of less than 35%.

RESULTS

No significant difference was noted in the duration of ICU stay (Group E: 1.13 ± 0.43 days; Group C: 1.18 ± 0.60 days, p = 0.710), the number of patients on a respirator for 24 hours or longer after surgery (Group E: 10.0%; Group C: 5.3%, p = 0.397), hospital mortality (Group E: 0%; Group C: 0%), or the frequency of postoperative major complications between two groups.

CONCLUSIONS

The outcomes of OPCAB using elective IABP in high-risk patients, such as those with severe LMCA stenosis or left ventricular dysfunction, were similar to those of OPCAB in low-risk patients, suggesting the usefulness of elective IABP in OPCAB.

A critical appraisal of propensity-score matching in the medical literature between 1996 and 2003

Propensity-score methods are increasingly being used to reduce the impact of treatment-selection bias in the estimation of treatment effects using observational data. Commonly used propensity-score methods include covariate adjustment using the propensity score, stratification on the propensity score, and propensity-score matching. Empirical and theoretical research has demonstrated that matching on the propensity score eliminates a greater proportion of baseline differences between treated and untreated subjects than does stratification on the propensity score. However, the analysis of propensity-score-matched samples requires statistical methods appropriate for matched-pairs data. We critically evaluated 47 articles that were published between 1996 and 2003 in the medical literature and that employed propensity-score matching. We found that only two of the articles reported the balance of baseline characteristics between treated and untreated subjects in the matched sample and used correct statistical methods to assess the degree of imbalance. Thirteen (28 per cent) of the articles explicitly used statistical methods appropriate for the analysis of matched data when estimating the treatment effect and its statistical significance. Common errors included using the log-rank test to compare Kaplan-Meier survival curves in the matched sample, using Cox regression, logistic regression, chi-squared tests, t-tests, and Wilcoxon rank sum tests in the matched sample, thereby failing to account for the matched nature of the data. We provide guidelines for the analysis and reporting of studies that employ propensity-score matching.

Long intraaortic balloon treatment time leads to more vascular complications

Intraaortic balloon counterpulsation is an established and efficient therapy. Limb ischemia is the most common complication. The impact of treatment duration on balloon-related complications was analyzed retrospectively in 135 patients who underwent balloon counterpulsation between 1998 and 2004. Thirty high-risk coronary patients required preoperative intraaortic balloon therapy, 41 were in preoperative cardiogenic shock, and 64 needed support for difficulties in weaning from cardiopulmonary bypass. No balloon-related mortality occurred. The overall balloon-related complication rate was 20/135 (14.8%); 18 had limb ischemia, of whom 6 (4.4%) required vascular interventions. Intraaortic balloon treatment time was significantly longer in patients who developed limb ischemia (99.8 +/- 54.1 h) compared to those who did not (34.4 +/- 30.4 h). Preoperative therapy had short treatment times and few complications. Intraaortic balloon pumping provides effective circulatory support with a low complication rate. A clear relationship was established between duration of treatment and balloon-related complications. Independent risk factors for balloon-related complications were long treatment time, acute myocardial infarction, age over 65 years, and ejection fraction less than 0.30.

Preoperative intra aortic balloon pumps in patients undergoing coronary artery bypass grafting

BACKGROUND

The intra aortic balloon pump (IABP) is a mechanical assist device which improves cardiac function. The device has a well-established place in algorithms for managing low cardiac output following cardiac surgery. There is increasing evidence that certain cardiac surgery patients benefit from a period of preoperative augmentation with the intra aortic balloon pump.

OBJECTIVES

To determine the effect of the preoperative intra aortic balloon pump on mortality and morbidity in a number of different patients groups undergoing coronary artery bypass grafting.

SEARCH STRATEGY

Searches were performed of the following databases: Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 1 2005), MEDLINE (2000-2005) and EMBASE (1998-2005). No language restrictions were applied.

SELECTION CRITERIA

Randomised or controlled trials of any size or length were included.

DATA COLLECTION AND ANALYSIS

Papers were assessed for inclusion by two reviewers independently. Differences were settled by consensus with a third reviewer. Data were extracted and entered into RevMan 4.1, through which a meta-analysis of the data was performed.

MAIN RESULTS

Five randomised controlled trials were identified from a total of 765 studies (4 on-pump and 1 off-pump). Data from a total of 193 patients were included in the meta-analysis; all on-pump. Generally, the patients were designated as "high risk" . 105 patients were treated preoperatively with IABP and 88 patients served as controls. There were three hospital deaths in the intervention arm and 18 in the non-intervention arm (odds ratio (OR) 0.16; 95% confidence intervals (CI): 0.06 to 0.4; P<0.0001). Low cardiac index (<2.0 L/min/m2) was noted in 21 out of 105 patients in the treatment arm and 59 patients out of 88 in the non-treatment arm (OR 0.14; 95% CI: 0.08 to 0.25; P<0.00001). A large proportion of the control group had an IABP inserted postoperatively for low cardiac index (52 out of 88). An off-pump versus on-pump analysis was not possible due to the limited number of off-pump studies. However a single well-conducted randomised controlled trial suggested favourable effect of the preoperative IABP in off-pump patients.

AUTHORS' CONCLUSIONS

Available evidence suggests the preoperative intra aortic balloon pump may have a beneficial effect on mortality and morbidity in specific high risk patient groups undergoing coronary artery bypass grafting, however, the randomised evidence is from a number of small trials, with a high proportion of unstable patients, recruited at a single institution.

A review of the application of propensity score methods yielded increasing use, advantages in specific settings, but not substantially different estimates compared with conventional multivariable methods

OBJECTIVE

Propensity score (PS) analyses attempt to control for confounding in nonexperimental studies by adjusting for the likelihood that a given patient is exposed. Such analyses have been proposed to address confounding by indication, but there is little empirical evidence that they achieve better control than conventional multivariate outcome modeling.

STUDY DESIGN AND METHODS

Using PubMed and Science Citation Index, we assessed the use of propensity scores over time and critically evaluated studies published through 2003.

RESULTS

Use of propensity scores increased from a total of 8 reports before 1998 to 71 in 2003. Most of the 177 published studies abstracted assessed medications (N=60) or surgical interventions (N=51), mainly in cardiology and cardiac surgery (N=90). Whether PS methods or conventional outcome models were used to control for confounding had little effect on results in those studies in which such comparison was possible. Only 9 of 69 studies (13%) had an effect estimate that differed by more than 20% from that obtained with a conventional outcome model in all PS analyses presented.

CONCLUSIONS

Publication of results based on propensity score methods has increased dramatically, but there is little evidence that these methods yield substantially different estimates compared with conventional multivariable methods.

The preoperative intraaortic balloon pump in coronary bypass surgery: a lack of evidence of effectiveness

BACKGROUND

There is limited evidence demonstrating the effectiveness of preoperative intraaortic balloon pump (IABP) use in isolated coronary artery bypass graft (CABG) surgery. A single-center randomized trial demonstrated its benefit. We undertook a multicenter observational study to verify this finding.

METHODS

In 29,950 consecutive patients undergoing isolated CABG between 1995 and 2000 at 10 centers, we compared patients with and without a preoperative IABP. We also compared the effect of preoperative IABP use within 7 high-risk clinical subgroups. To validate the previous randomized trial, patients with any 2 of the following were also analyzed: left main > 70%, ejection fraction < 40%, redo CABG, or preoperative intravenous nitroglycerin.

RESULTS

Preoperative IABPs were used in 1896 patients (6.3%). These patients had more comorbid conditions and a higher crude mortality than those who did not have preoperative IABPs (9.5% vs 2.3%, P < .0001). Preoperative IABP patients were caliper matched to non-preoperative IABP patients using a propensity score. Excess mortality associated with preoperative IABP persisted (9.2% vs 5.8%, P = .0004). In 7 high-risk subgroups, mortality was significantly higher with preoperative IABP. We used propensity caliper matching to compare preoperative IABP with non-preoperative IABP patients who met trial criteria (n = 4332). Preoperative IABP was associated with higher mortality (11.0% vs 6.5%, P = .0009). Removing emergency patients did not alter results.

CONCLUSIONS

Use of preoperative IABPs was consistently associated with higher mortality. Despite detailed statistical analysis, we were unable to show benefit from preoperative IABP use or confirm the results of a single-center trial that demonstrated its benefit. Assessment of preoperative IABP efficacy will require a randomized trial.