Effect of a Perioperative Intra-Aortic Balloon Pump in High-Risk Cardiac Surgery Patients: A Randomized Clinical Trial

Preoperative prophylactic insertion of intraaortic balloon pumps in critically ill patients undergoing coronary artery bypass surgery: a meta-analysis of RCTS

BACKGROUND

The intra-aortic balloon pump (IABP) technique plays a crucial role in providing circulatory support for patients experiencing hemodynamic instability. This study aimed to assess the effectiveness and safety of preoperative prophylactic IABP insertion in patients undergoing acute critical coronary artery bypass grafting (CABG).

METHODS

A comprehensive search was conducted in PubMed, Cochrane Library, and Embase databases, covering the period from January 1995 to September 2022.

RESULTS

The incidence of renal insufficiency, mechanical ventilation exceeding 24 h, and bleeding events in the IABP group did not exhibit significant differences compared to the control group (relative risk [RR] = 0.85, P = 0.26; RR = 0.81, P = 0.08; RR = 0.95, P = 0.87). However, the hospital mortality rate was significantly lower in the IABP group than in the control group (RR = 0.54, P = 0.0007), and the length of ICU stay was shorter in the IABP group (mean difference [MD] = -1.12, P < 0.000001). The IABP group also exhibited a lower incidence of low cardiac output syndrome (LCOS%) compared to the control group (RR = 0.61, P < 0.0001), and a lower incidence of major adverse cardiac and cerebrovascular events (MACCE%) (RR = 0.70, P = 0.001). No significant publication bias was observed in the funnel plot analysis.

CONCLUSION

Preoperative prophylactic insertion of IABP is currently considered beneficial in improving outcomes for critically ill patients undergoing CABG. This technique reduces hospital mortality, shortens ICU stays, and lowers the incidence of LCOS% and MACCE%.

Preoperative intra-aortic balloon pump in patients with ST-elevation myocardial infarction undergoing urgent cardiac bypass surgery

BACKGROUND

In patients with ST-elevation myocardial infarction (STEMI), either with or without cardiogenic shock, mechanical circulatory support with an intra-aortic balloon pump (IABP) is not associated with lower mortality. However, in STEMI patients undergoing urgent coronary artery bypass grafting (CABG), preoperative insertion of an IABP has been suggested to reduce mortality. In this study, the effect of preoperative IABP use on mortality in STEMI patients undergoing urgent CABG was investigated.

METHODS

All consecutive STEMI patients undergoing urgent CABG in a single centre between 2000 and 2018 were studied. The primary outcome, 30-day mortality, was compared between patients with and without a preoperative IABP. Subgroup analysis and multivariable analysis using a propensity score and inverse probability treatment weighting were performed to adjust for potential confounders.

RESULTS

A total of 246 patients were included, of whom 171 (69.5%) received a preoperative IABP (pIABP group) and 75 (30.5%) did not (non-pIABP group). In the pIABP group, more patients suffered from cardiogenic shock, persistent ischaemia and reduced left ventricular function. Unadjusted 30-day mortality was comparable between the pIABP and the non-pIABP group (13.3% vs 12.3%, p = 0.82). However, after correction for confounders and inverse probability treatment weighting preoperative IABP was associated with reduced 30-day mortality (relative risk 0.52, 95% confidence interval 0.30-0.88).

CONCLUSION

In patients with STEMI undergoing urgent CABG, preoperative insertion of an IABP is associated with reduced mortality.

Temporary mechanical circulatory support & enhancing recovery after cardiac surgery

PURPOSE OF REVIEW

This review highlights the integration of enhanced recovery principles with temporary mechanical circulatory support associated with adult cardiac surgery.

RECENT FINDINGS

Enhanced recovery elements and efforts have been associated with improvements in quality and value. Temporary mechanical circulatory support technologies have been successfully employed, improved, and the value of their proactive use to maintain hemodynamic goals and preserve long-term myocardial function is accruing.

SUMMARY

Temporary mechanical circulatory support devices promise to enhance recovery by mitigating the risk of complications, such as postcardiotomy cardiogenic shock, organ dysfunction, and death, associated with adult cardiac surgery.

Postcardiotomy Shock Syndrome: A Narrative Review of Perioperative Diagnosis and Management

Postcardiotomy shock (PCS) is generally described as the inability to separate from cardiopulmonary bypass due to ineffective cardiac output after cardiotomy, which is caused by a primary cardiac disorder, resulting in inadequate tissue perfusion. Postcardiotomy shock occurs in 0.5% to 1.5% of contemporary cardiac surgery cases, and is accompanied by an in-hospital mortality of approximately 67%. In the last 2 decades, the incidence of PCS has increased, likely due to the increased age and baseline morbidity of patients requiring cardiac surgery. In this narrative review, the authors discuss the epidemiology and pathophysiology of PCS, the rationale and evidence behind the initiation, continuation, escalation, and discontinuation of mechanical support devices in PCS, and the anesthetic implications.

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.

Prolonged Mechanical Ventilation Following Coronary Artery Bypass Graft in Santiago De Cali, Colombia

Purpose

The purpose of this study was to describe factors associated with prolonged ventilatory support in subjects undergoing coronary artery bypass graft.

Patients and Methods

This was an analytical retrospective case-control study. Cases were defined as subjects requiring prolonged mechanical ventilation (>48 hours) following isolated coronary artery bypass graft. Subjects older than 18 years who had undergone surgery were included, while subjects with missing clinical record data, subjects in coma or subjects with prior cardiac surgery were excluded. Variables were measured at the three time points surrounding surgery.

Results

A total of 204 cases and 408 controls were included. The final logistic model showed an association between prolonged mechanical ventilation and the following presurgical variables: chronic obstructive pulmonary disease (OR 1.85; 95% CI: 1.06-3.23, p = 0.03) and chronic kidney disease (OR 1.90; 95% CI: -3.31; p = 0.02). The associated transurgical variable was the use of intra-aortic balloon pump (OR 3.63; 95% CI: 1.73-7.61, p = 0.00), and associated postsurgical variables were venous oxygen saturation <60% (OR 2.00; 95% CI: 1.18-3.40, p = 0.01), mediastinitis (OR 18.51; 95% CI: 4.06-84.40, p = 0.00), inotrope use (OR 2.82; 95% CI: 1.77-4.48, p = 0.00), pleural effusion requiring drainage (OR 3.57; 95% CI: 2.02-6.32, p = 0.00) and delirium (OR 3.45; 95% CI: 1.91-6.25, p = 0.00).

Conclusion

This study identifies factors associated with prolonged mechanical ventilation in subjects subject to coronary artery bypass graft over the presurgical, transurgical and postsurgical periods, identifying a new factor, delirium, for this type of population.

Still a place for aortic counterpulsation in cardiac surgery and patients with cardiogenic shock?

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2021. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2021 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901 .

Routine Intraoperative Inhaled Milrinone and Iloprost Reduces Inotrope Use in Patients Undergoing Cardiac Surgery: A Retrospective Cohort Pilot Study

BACKGROUND

Catecholamine inotropes are frequently used after cardiopulmonary bypass (CPB) but may have undesirable effects. The aim was to identify whether the routine use of inhaled pulmonary vasodilators might reduce the requirement for inotrope drugs after cardiac surgery.

METHODS

Retrospective cohort study of sequential patients undergoing cardiac surgery at the Royal Melbourne Hospital performed by a single surgeon and anesthesia care team, within 14 months before and after routine implementation of inhaled pulmonary vasodilators, August 2017. Milrinone 4 mg and iloprost 20 µg were inhaled using a vibrating mesh nebulizer (Aerogen) before initiation of CPB and at chest closure. Other aspects of clinical management were unaltered over the time period. Two investigators blinded to each other extracted data from electronic and written medical records. The primary outcome was any use of inotropes in the perioperative period; a Fisher exact test was used to analyze any differences between the 2 groups. Demographic data, hemodynamic data, and use of inotropes and vasopressors were collected from induction of anesthesia to 36 hours postoperative in the intensive care unit (ICU). Hospital and ICU length of stay, cost, and complications were collected.

RESULTS

Any use of inotropes was significantly lower with inhaled pulmonary dilators (62.5% vs 86.8%, odds ratio [95% confidence interval {CI}], 0.253 (0.083-0.764); P = .011), including intraoperative inotrope use (37.5% vs 86.8%, odds ratio [95% CI], 0.091 (0.03-0.275); P < .001). ICU length of stay was significantly lower with inhaled pulmonary dilators (45 hours, interquartile range [IQR], 27-65 vs 50 hours, IQR, 45-74; P = .026). There were no significant differences among major postoperative complications or costs between groups.

CONCLUSIONS

Routine use of inhaled milrinone 4 mg and iloprost 20 µg before and after CPB is associated with reduced postoperative inotrope use.

Preoperative Use of Intra-Aortic Balloon Pump Support Reduced 30-Day Mortality in a Population with LVEF >35% and High Surgical Risk after Coronary Artery Bypass Graft Surgery

Introduction: The intra-aortic balloon pump (IABP) is used to prevent complications after coronary artery bypass grafting (CABG) surgery, although some results are controversial and basal ventricular function may play a role. This study assessed the benefit of preoperative use of IABP, as stratified by the ventricular function, in a population submitted to high-surgical-risk CABG. Methods: Patients >18 years old, with multiple coronary artery disease and thus candidates for CABG, were included. Cardiogenic shock, acute myocardial infarction (AMI), acute ventricle mechanical dysfunction, severe aortic regurgitation, tachyarrhythmia, massive pulmonary embolism, coagulopathy, or low life expectancy were exclusion criteria. Results: One hundred and twenty-nine patients aged 65 years old with hypertension, dyslipidemia, type 2 diabetes mellitus, and mean left ventricular ejection fraction (LVEF) 46% constituted the study population. No difference was observed at 30-day mortality endpoint (IABP vs. no IABP, 17 vs. 24%, OR 0.63, p = 0.20; AMI 25 vs. 31%, OR 0.75, p = 0.29). After LVEF stratification, the subgroup of 48 (75%) patients under IABP support and LVEF >35% had a reduced 30-day mortality risk (LVEF ≤35% vs. LVEF >35%, 37.5 vs. 10.4%, OR 0.3, p = 0.03), independently from potential confounders and showing an interaction with European System for Cardiac Operative Risk Evaluation-II (EuroSCORE-II). At secondary endpoints, IABP use was associated with a lower prevalence of acute renal failure and renal replacement therapy, but with a longer stay in the intensive care unit and longer hospitalization time. Conclusion: The preoperative use of IABP was associated with an independent reduction of 30-day mortality risk in cases with LVEF >35% in a population submitted to high-surgical-risk CABG. Likewise, the use of IABP was associated with a lower risk of postoperative renal complications.

Outcome analysis for prediction of intraaortic balloon pump support failure and long-term survival in high-risk patients undergoing mitral valve surgery

The outcome predictors of intra-aortic balloon pump (IABP) in patients who undergo mitral valve surgery remain unknown. This study aimed to retrospectively review valvular surgery in patients who received an IABP to identify the predictors of failure of IABP support and anticipate the necessary therapy. This retrospective observational study recruited a total of 157 consecutive patients who underwent open-heart mitral valve surgery with IABP implantation intraoperatively or postoperatively. Univariate and multivariate logistic regression analyses were performed to identify the risk factors attributed to 30-day mortality. Follow-up data of survivors were collected to investigate the effect of IABP support to evaluate long-term outcomes. The overall 30-day mortality was 35.7% (56 patients). The following factors that contributed to 30-day mortality included sepsis (P < .001, OR: 5.627, 95%CI: 2.422-11.683); IABP implantation postoperatively rather than intraoperatively (P = .001, OR: 6.395, 95%CI: 2.085-19.511); right heart failure (P = .042, OR: 3.419, 95%CI: 1.225-12.257); and lack of subvalvular apparatus preservation (P = .033, OR: 3.710, 95%CI: 1.094-13.167). Furthermore, follow-up data of these patients showed an estimation of 5-year and 10-year survival rates of 58.9% and 35.7%, respectively. Patients with intraoperative IABP demonstrated better long-term survival outcomes when compared to those with postoperative IABP (χ²  = 4.291, P = .038). In summary, this study distinguished the preoperative predictors of 30-day mortality of IABP-support in mitral valve surgery patients. These results indicated that early intervention with IABP should be taken into consideration in case of hemodynamic instability in critically ill patients undergoing mitral valve surgery.

Intra-aortic balloon pump does not influence cerebral hemodynamics and neurological outcomes in high-risk cardiac patients undergoing cardiac surgery: an analysis of the IABCS trial

Background

The intra-aortic balloon pump (IABP) is often used in high-risk patients undergoing cardiac surgery to improve coronary perfusion and decrease afterload. The effects of the IABP on cerebral hemodynamics are unknown. We therefore assessed the effect of the IABP on cerebral hemodynamics and on neurological complications in patients undergoing cardiac surgery who were randomized to receive or not receive preoperative IABP in the ‘Intra-aortic Balloon Counterpulsation in Patients Undergoing Cardiac Surgery’ (IABCS) trial.

Methods

This is a prospectively planned analysis of the previously published IABCS trial. Patients undergoing elective coronary artery bypass surgery with ventricular ejection fraction ≤ 40% or EuroSCORE ≥ 6 received preoperative IABP (n = 90) or no IABP (n = 91). Cerebral blood flow velocity (CBFV) of the middle cerebral artery through transcranial Doppler and blood pressure through Finometer or intra-arterial line were recorded preoperatively (T1) and 24 h (T2) and 7 days after surgery (T3) in patients with preoperative IABP (n = 34) and without IABP (n = 33). Cerebral autoregulation was assessed by the autoregulation index that was estimated from the CBFV response to a step change in blood pressure derived by transfer function analysis. Delirium, stroke and cognitive decline 6 months after surgery were recorded.

Results

There were no differences between the IABP and control patients in the autoregulation index (T1: 5.5 ± 1.9 vs. 5.7 ± 1.7; T2: 4.0 ± 1.9 vs. 4.1 ± 1.6; T3: 5.7 ± 2.0 vs. 5.7 ± 1.6, p = 0.97) or CBFV (T1: 57.3 ± 19.4 vs. 59.3 ± 11.8; T2: 74.0 ± 21.6 vs. 74.7 ± 17.5; T3: 71.1 ± 21.3 vs. 68.1 ± 15.1 cm/s; p = 0.952) at all time points. Groups were not different regarding postoperative rates of delirium (26.5% vs. 24.2%, p = 0.83), stroke (3.0% vs. 2.9%, p = 1.00) or cognitive decline through analysis of the Mini-Mental State Examination (16.7% vs. 40.7%; p = 0.07) and Montreal Cognitive Assessment (79.16% vs. 81.5%; p = 1.00).

Conclusions

The preoperative use of the IABP in high-risk patients undergoing cardiac surgery did not affect cerebral hemodynamics and was not associated with a higher incidence of neurological complications.

Trial registrationhttp://www.clinicaltrials.gov (NCT02143544).

Preoperative intra-aortic balloon pump inserted in acute myocardial infarction patients without cardiogenic shock undergoing surgical coronary revascularization

OBJECTIVES

The benefit of preoperative intra-aortic balloon pump implantation in high-risk cardiac surgery patients is still debated. The role of preoperative intra-aortic balloon pump insertion in acute myocardial infarction patients without cardiogenic shock undergoing off-pump coronary artery bypass grafting remains unknown. This study aimed to determine the efficacy and safety of the preoperative intra-aortic balloon pump insertion in those patients undergoing off-pump coronary artery bypass grafting.

METHODS

A total of 421 consecutive acute myocardial infarction patients without cardiogenic shock who underwent isolated off-pump coronary artery bypass grafting were enrolled in this retrospective observational propensity score-matched analysis study. Patients who received intra-aortic balloon pump before off-pump coronary artery bypass grafting (the intra-aortic balloon pump group, n = 157) were compared with those who had not (control group, n = 264). The 30-day postoperative survival, postoperative complications, and postoperative hospital length of stay were compared between the two groups.

RESULTS

A total of 99 pairs of patients were matched. The preoperative intra-aortic balloon pump did not show a 30-day postoperative survival benefit compared with the control group (hazard ratio, 0.9; 95% confidence interval, 0.2-4.2; p = 0.92). Patients with preoperative intra-aortic balloon pump were more likely to have shorter postoperative lengths of stay (8 (6-11) days vs. 10 (6-15) days, p = 0.02) and decreased total days in the hospital (median days: 18.2 vs. 21.8, p = 0.02) compared to patients without balloon pumps.

CONCLUSION

Preoperative intra-aortic balloon pump insertion in acute myocardial infarction patients without cardiogenic shock undergoing off-pump coronary artery bypass grafting improved convalescence as shown by significantly shorter postoperative lengths of hospital stay.

Mechanical support for high-risk coronary artery bypass grafting

Mechanical circulatory support devices are being used to an increasing extent. The use of these devices as an adjunct to cardiac surgery to support ventricular function has contributed to improved outcomes for the highest risk patients. In the context of patients undergoing coronary artery bypass grafting, there are several potential indications for mechanical circulatory support: preoperatively in the setting of acute cardiogenic shock, or in patients with intractable angina with or without haemodynamic compromise; at induction of anaesthesia prophylactically in patients with critical coronary anatomy and/or severely impaired left ventricular function; intraoperatively in the setting of failure to wean from cardiopulmonary bypass; or postoperatively in patients who develop an intractable low cardiac output state. The use of the intra-aortic balloon pump, veno-arterial extracorporeal membrane oxygenation, TandemHeart, Impella and central ventricular assist devices will be considered in the setting of high-risk patients undergoing coronary artery bypass grafting.