Impact of prophylactic intra-aortic balloon pump on early outcomes in patients with severe left ventricular dysfunction undergoing elective coronary artery bypass grafting with cardiopulmonary bypass

OBJECTIVE

Our aim was to analyse whether prophylactic preoperative intraaortic balloon pump (IABP) improves outcomes in hemodynamically stable patients with low left ventricular ejection fraction (LVEF ≤30%) undergoing elective myocardial revascularization (CABG) using cardiopulmonary bypass (CPB). Secondary aim was to identify the predictors for low cardiac output syndrome (LCOS).

METHODS

Prospectively collected data of 207 consecutive patients with LVEF ≤30% undergoing elective isolated CABG with CPB from 01/2009 to 12/2019, 136 with and 71 patients without IABP, were retrieved retrospectively. Patients with prophylactic IABP were matched 1:1 with patients without IABP by a propensity score matching. Stepwise logistic regression was conducted to identify predictors of postoperative LCOS in the propensity-matched cohort. P value ≤0.05 was considered significant.

RESULTS

Reduced postoperative LCOS (9.9% vs. 26.8%, P = 0.017) was observed in patients receiving prophylactic IABP. Stepwise logistic regression identified preoperative IABP as preventive factor for postoperative LCOS [Odds Ratio (OR) 0.19,95% Confidence Interval (CI), 0.06-0.55, P = 0.004]. The need of vasoactive and inotropic support was lower in patients with prophylactic IABP at 24, 48 and 72 h after surgery (12.3 [8.2-18.6] vs. 22.2 [14.4-28.8], P < 0.001, 7.7 [3.3-12.3] vs.16.3 [8.9-27.8], P < 0.001 and 2.4 [0-7] vs. 11.5 [3.1-26], P < 0.001, respectively). The patients in both groups did not differ in terms of in-hospital mortality (7.0% vs. 9.9%, P = 0.763). There were no major IABP-related complications.

CONCLUSIONS

Elective patients with left ventricular ejection fraction ≤30% undergoing CABG with CPB and prophylactic IABP insertion had less low cardiac output syndrome and similar in-hospital mortality.

Risk factors for in-hospital mortality after coronary artery bypass grafting in Colombia

BACKGROUND

To determine the factors associated with in-hospital mortality after a coronary artery bypass (CABG) in a high-complexity clinic in the city of Santiago de Cali.

METHODS

A retrospective case-control analytical study was performed. Cases were defined as adult patients that had undergone CABG and died within 30 days of the surgery. Patients aged ≥18 years that had undergone isolated surgeries, i.e. procedures without other interventions combined, were included. This study excluded patients that had missing data in their medical records, had previously been in a state of coma, or had previously undergone cardiac surgery other than a bypass procedure. Exposure variables were measured at three stages: preoperative, intraoperative, and postoperative.

RESULTS

The study included 77 cases and 308 controls. The most common cause of death was cardiogenic shock (53.2%), followed by sepsis (27.3%). The multinomial logistic regression model revealed an association of in-hospital mortality with preoperative variables of age >75 years (odds ratio [OR] 2.5, 95% confidence interval [CI95%]: 1.1-5.8, p = 0.032), low socioeconomic status (OR 2.3, CI95%: 1.1-5.2, p = 0.034), heart failure (HF) (OR 3.2, CI95%: 1.5-7.0, p = 0.002), unstable angina (OR 4.2, CI95%: 1.9-9.0, p = 0.000), acute myocardial infarction (AMI) ≤7 days (OR 3.9, CI95%: 1.1-13.7, p = 0.037), chronic kidney insufficiency (CKI) (OR 2.9, CI95%: 1.2-7.0, p = 0.018), peripheral vascular disease (PVD) (OR 2.8, CI95%: 1.2-6.8, p = 0.019), and urgent/emergent surgery (OR 8.2, CI95%: 2.0-34.5, p = 0.004). Of the intraoperative variables, the model showed an association between the use of inotropic agents (OR 2.8, CI95%: 1.3-6.4, p = 0.011) and cardiogenic shock (OR 50.6, CI95%: 7.5-339, p = 0.000).

CONCLUSIONS

This study identifies the factors during preoperative and intraoperative periods that are associated with in-hospital mortality in patients that have undergone CABG.

Risk assessment of acute kidney injury following cardiopulmonary bypass

BACKGROUND

Acute kidney injury (AKI) is a frequent and serious complication of cardiac surgery, associated with a high incidence of morbidity and mortality. Although the RIFLE criteria serve as a prominent tool to identify patients at high risk of AKI, an optimized diagnosis model in clinical practice is desired.

METHODS

Based on the SOP-criteria, 365 patients (10%) developed AKI following surgery and were subjected to RRT. In contrast, the incidence of AKI, defined according to the RIFLE criteria, was only 7% (n = 251 patients). Prominent risk factors identified by SOP were patients' sex, valve and combined valve and bypass surgery, deep hypothermia, use of intra-aortic balloon pump (IABP) and previous coronary interventions. Ischemia, reperfusion, blood loss and surgery time also served as significant risk factors for patient evaluated by SOP.

RESULTS

Risk assessment by RIFLE differed in as much as most patients with normothermia and those receiving only cardiovascular bypass developed AKI. However, patients' sex and valve surgery did not serve as a risk factor.

CONCLUSION

Evaluation of patients by the RIFLE versus SOP criteria yielded different results with more AKI patients detected by SOP. Based on the present data, it is concluded that patients may not prone to AKI when surgery and ischemia time will be kept short, when blood loss is mitigated to a minimum and when surgery is performed under non-hypothermic conditions.

Prophylactic intra-aortic balloon counterpulsation before surgical myocardial revascularization in patients with acute myocardial infarction

Introduction:

Prophylactic intra-aortic balloon counterpulsation (pIABC) is recommended for high-risk patients undergoing coronary artery bypass grafting (CABG) surgery. Criteria for high-risk patients benefiting from pIABC are unclear. This study aimed to specifically describe the effect of pIABC on outcomes of patients with acute myocardial infarction (AMI) undergoing CABG.

Methods:

In 178 of 484 AMI patients (non-ST-segment elevation myocardial infarction [NSTEMI] or ST-segment elevation myocardial infarction [STEMI] ≤5 days before surgery) without cardiogenic shock who underwent CABG between 2008 and 2013, pIABC was initiated preoperatively. After propensity score matching, the outcomes of 400 patients were analyzed (pIABC: 150; Control: 250).

Results:

After propensity score matching, baseline and operative characteristics were balanced between the groups except for a higher rate of patients with a left ventricular ejection fraction (LVEF)≤30% in the pIABC group (26% vs. Control: 13%; p=0.032). Seven point two percent (7.2%) of the control patients received an IABP intraoperatively or postoperatively. Postoperative extracorporeal life support (ECLS) was only needed in the control group (1.2% vs. 0%; p=0.01). Postoperative plasma curves of troponin I, creatine kinase (CK) and creatine kinase isoform MB (CK-MB) levels were reduced in the pIABC group compared with the control group. In-hospital mortality was reduced in the pIABC group (3.3% vs. control: 6.4%; p=0.18). After multivariate adjustment for other preoperative risk factors, pIABC was significantly protective concerning in-hospital mortality (HR 0.56; 95%-CI 0.023-0.74; p=0.021). Mortality (pIABC vs. control) was more affected in patients with preoperative LVEF≤30% (2/36 (5.6%) vs. 6/31 (19%); heart rate (HR) 0.25; 95%-CI 0.046-1.3; p=0.13) compared with LVEF>30% (3/114 (2.6%) vs. 10/219 (4.6%); HR 0.56; 95%-CI 0.15-2.1; p=0.55). Long-term survival did not differ between the groups.

Conclusions:

pIABC in CABG for AMI is associated with reduced perioperative cardiac injury and in-hospital mortality. Long-term survival is not affected.

Short-term outcomes of preoperative intra-aortic balloon pump use in patients undergoing adjunctive coronary endarterectomy: a retrospective observational study

Background:

Coronary artery bypass grafting (CABG) combined with coronary endarterectomy (CE) can be associated with high operative mortality and morbidity. An intra-aortic balloon pump (IABP) has been the most widely used mechanical circulatory support device during perfusion treatment. However, the benefits of preoperative IABP in CABG combined with CE remain unknown. We conducted a retrospective observational study to evaluate the efficacy of preoperative IABP therapy in patients undergoing adjunctive right coronary artery (RCA) endarterectomy.

Methods:

Between May 2013 and May 2016, 120 patients undergoing off-pump coronary artery bypass grafting (OPCABG) with RCA endarterectomy who received preoperative IABP support (IABP group, n=56) or who did not receive preoperative IABP support (control group, n=64) were evaluated retrospectively.

Results:

Patients in the IABP group had a significantly lower mean preoperative ejection fraction and a significantly higher mean EuroSCORE (both <0.05). The incidence of inferior myocardial infarction (MI) was significantly lower in the IABP group than in the control group (3.6% vs 15.6%, RR = 0.23, 95% CI 0.05-1.00, p=0.03). Hospital mortality was similar in the two groups (3.6% vs 4.7%, RR= 0.76, 95% CI 0.13-4.40, p=0.76). There were no significant differences between the two groups with respect to the rates of prolonged ventilation, low cardiac output syndrome, renal failure requiring dialysis, re-operation for bleeding or IABP-related complications. Preoperative IABP may be a protective factor of inferior MI (HR = 0.031, 95% CI 0.004-0.211, p<0.001)

Conclusions:

The preoperative use of IABP could reduce the incidence of postoperative MI in patients undergoing CABG with CE and seemed to shift high-risk patients into a lower-risk category.

Is delayed surgical revascularization in acute myocardial infarction useful or dangerous? New insights into an old problem

OBJECTIVES

Haemodynamically stable patients admitted for coronary artery bypass grafting in acute myocardial infarction often undergo delayed surgery in order to avoid the risks of emergency surgery. However, initially stable patients undergoing delayed surgery may develop low cardiac output syndrome (LCOS) during the waiting period, which might be a major drawback of this strategy. We aim to define risk factors and clinical consequences of LCOS during the waiting period.

METHODS

A total of 530 consecutive patients with acute myocardial infarction (33% non-ST-segment elevation myocardial infarction and 67% ST-segment-elevation myocardial infarction) underwent isolated coronary artery bypass grafting between 2008 and 2013. Outcomes after either immediate (<48 h after onset of symptoms) or delayed (>48 h after onset of symptoms) therapy were compared. Predictors of preoperative development of LCOS were identified using multivariate regression analysis.

RESULTS

Of the 327 patients undergoing delayed therapy, 39 (12%) developed preoperative LCOS, resulting in increased mortality compared with patients who remained stable (21 vs 7.6%, P < 0.001). Immediate therapy resulted in similar mortality compared with delayed therapy (6.4 vs 7.6%; P = 0.68) and better 7-year survival (70 vs 55%; P < 0.001). Predictors of developing LCOS were reduced left ventricular function (odds ratio 4.4), renal impairment (odds ratio 3.0), acute pulmonary infection (odds ratio 3.4) and the extent of troponin elevation at admission (odds ratio 1.01 per increase by 1 µg/l).

CONCLUSIONS

In patients with acute myocardial infarction undergoing delayed coronary artery bypass grafting, preoperative LCOS is a relevant and dangerous condition that can be avoided by operating immediately or by carefully selecting patients to be delayed according to the risk parameters identified preoperatively.

Cerebral hemodynamics with intra-aortic balloon pump: business as usual?

OBJECTIVE

Intra-aortic balloon pump (IABP) is commonly used as mechanical support after cardiac surgery or cardiac shock. Although its benefits for cardiac function have been well documented, its effects on cerebral circulation are still controversial. We hypothesized that transfer function analysis (TFA) and continuous estimates of dynamic cerebral autoregulation (CA) provide consistent results in the assessment of cerebral autoregulation in patients with IABP.

APPROACH

Continuous recordings of blood pressure (BP, intra-arterial line), end-tidal CO₂, heart rate and cerebral blood flow velocity (CBFV, transcranial Doppler) were obtained (i) 5 min with IABP ratio 1:3, (ii) 5 min, starting 1 min with the IABP-ON, and continuing for another 4 min without pump assistance (IABP-OFF). Autoregulation index (ARI) was estimated from the CBFV response to a step change in BP derived by TFA and as a function of time using an autoregressive moving-average model during removal of the device (ARI _t ). Critical closing pressure and resistance area-product were also obtained.

MAIN RESULTS

ARI with IABP-ON (4.3  ±  1.2) were not different from corresponding values at IABP-OFF (4.7  ±  1.4, p  =  0.42). Removal of the balloon had no effect on ARI _t , CBFV, BP, cerebral critical closing pressure or resistance area-product.

SIGNIFICANCE

IABP does not disturb cerebral hemodynamics. TFA and continuous estimates of dynamic CA can be used to assess cerebral hemodynamics in patients with IABP. These findings have important implications for the design of studies of critically ill patients requiring the use of different invasive support devices.

Clinical Characteristics and Outcomes of Patients With Myocardial Infarction and Cardiogenic Shock Undergoing Coronary Artery Bypass Surgery: Data From The Society of Thoracic Surgeons National Database

BACKGROUND

Acute myocardial infarction complicated by cardiogenic shock (AMI-CS) is associated with substantial mortality. We evaluated outcomes of patients in The Society of Thoracic Surgeons Adult Cardiac Surgery Database who underwent coronary artery bypass graft surgery (CABG) in the setting of AMI-CS.

METHODS

All patients with AMI-CS who underwent nonelective CABG or CABG with ventricular assist device implantation within 7 days after myocardial infarction were enrolled. The primary analysis sample consisted of patients who underwent surgery between June 2011 and December 2013. Baseline characteristics, operative findings, outcomes, and the utilization of mechanical circulatory support (MCS) were assessed in detail in this population. We also evaluated trends in unadjusted mortality for all patients undergoing CABG or CABG with ventricular assist device for AMI-CS from January 2005 to December 2013.

RESULTS

A total of 5,496 patients met study criteria, comprising 1.5% of all patients undergoing CABG during the study period. Overall operative mortality was 18.7%, decreasing from 19.3% in 2005 to 18.1% in 2013 (p < 0.001). Use of MCS increased from 5.8% in 2011 to 8.8% in 2013 (p = 0.008). Patients receiving MCS had a high proportion of cardiovascular risk factors or high clinical acuity. Patients requiring preoperative and patients requiring intraoperative or postoperative MCS had operative mortality of 37.2% and 58.4%, respectively. Patients undergoing CABG as a salvage procedure had an operative mortality of 53.3%, and a high incidence of reoperation (21.8%), postoperative respiratory failure requiring prolonged ventilation (59.7%), and renal failure (18.5%).

CONCLUSIONS

Most patients undergoing CABG for AMI-CS have a sizeable but not prohibitive risk. Patients who require MCS and those undergoing operation as a salvage procedure reflect higher risk populations.

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.

Cardiopulmonary bypass and intra-aortic balloon pump use is associated with higher short and long term mortality after transcatheter aortic valve replacement: a PARTNER trial substudy

BACKGROUND

Transcatheter aortic valve replacement (TAVR) with the balloon-expandable Sapien transcatheter heart valve improves survival compared to standard therapy in patients with severe aortic stenosis (AS) and is noninferior to surgical aortic valve replacement (AVR) in patients at high operative risk. Nonetheless, a significant proportion of patients may require pre-emptive or emergent support with cardiopulmonary bypass (CPB) and/or intra-aortic balloon pump (IABP) during TAVR due to pre-existing comorbid conditions or as a result of procedural complications.

OBJECTIVES

We hypothesized that patients who required CPB or IABP would have increased periprocedural complications and reduced long-term survival. In addition, we sought to determine whether preprocedural variables could predict the need for CPB and IABP.

METHODS

The study population included 2,525 patients in the PARTNER Trial (Cohort A and B) and the continuing access registry (CAR). Patients that received CPB or IABP were compared to patients that did not receive either, and then further divided into those that received support pre-TAVR and those that were placed on support emergently.

RESULTS

One-hundred sixty-three patients (6.5%) were placed on CPB and/or IABP. The use of CPB or IABP was associated with higher 1 year mortality (49.1% vs. 21.6%, P < 0.001). In multivariable analysis, utilization of CPB or IABP was an independent predictor of 30 day (HR 6.95) and 1-year (HR 2.56) mortality. Although mortality was highest in emergent cases, mortality was also greater in planned CPB and IABP cases compared with non-CPB/IABP cases (53.3% and 40.3% vs. 21.6%, P < 0.001).

CONCLUSIONS

These findings indicate that CPB and IABP use in TAVR portends a poor prognosis and its utilization, particularly in the setting of pre-emptive use, needs reconsideration.

Preoperative intra-aortic balloon pump to reduce mortality in coronary artery bypass graft: a meta-analysis of randomized controlled trials

Introduction

The intra-aortic balloon pump is routinely used in cardiac surgery; however, its impact on outcome is still a matter of debate and several randomized trials have been published recently. We perform an updated meta-analysis of randomized controlled trials that investigated the use of preoperative intra-aortic balloon pump in adult patients undergoing coronary artery bypass grafting.

Methods

Potentially eligible trials were identified by searching the Medline, Embase, Scopus, ISI Web of Knowledge and The Cochrane Library. Searches were not restricted by language or publication status and were updated in August 2014. Randomized controlled trials on preoperative intra-aortic balloon pump in patients undergoing coronary artery bypass grafting either with or without cardiopulmonary bypass were identified. The primary end point was mortality at the longest follow-up available and the secondary end point was 30-day mortality.

Results

The eight included randomized clinical trials enrolled 625 patients (312 to the intra-aortic balloon pump group and 313 to control). The use of intra-aortic balloon pump was associated with a significant reduction in the risk of mortality (11 of 312 (3.5%) versus 33 of 313 (11%), risk ratio = 0.38 (0.20 to 0.73), P for effect = 0.004, P for heterogeneity = 0.7, I-square = 0%, with eight studies included). The benefit on mortality reduction was confirmed restricting the analysis to trials with low risk of bias, to those reporting 30-day follow-up and to patients undergoing coronary artery bypass graft surgery with cardiopulmonary bypass.

Conclusions

Preoperative intra-aortic balloon pump reduces perioperative and 30-day mortality in high-risk patients undergoing elective coronary artery bypass grafting.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0728-1) contains supplementary material, which is available to authorized users.

Intra-aortic balloon counterpulsation in contemporary practice - where are we?

The intra-aortic balloon pump (IABP) remains the most widely used form of mechanical circulatory support in current clinical practice. This article will review the current evidence to guide IABP use, focussing on large registry and prospective, randomised data, and seek to establish appropriate roles for the IABP in contemporary practice. Despite a paucity of clinical evidence, the IABP remains a useful clinical tool in selected settings, although its routine, up-front use in relatively unselected MI populations is not supported by data. Although current evidence no longer supports routine use in certain high-risk groups, further studies of appropriately selected high-risk patients may yet demonstrate benefit in patients with moderate-severe degrees of shock.

Prophylactic intra-aortic balloon counterpulsation in cardiac surgery: it is time for clear evidence

In the previous issue of Critical Care, Yu and colleagues report increased morbidity and mortality in patients after myocardial infarction undergoing prophylactic intra-aortic balloon pump support before coronary artery bypass graft surgery. The impact of prophylactic intra-aortic balloon pump implantation before coronary artery bypass graft therapy still is controversially debated. However, Yu and colleagues emphasize further discussion and substantiate the need for a prospective randomized controlled trial on this subject.

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.