Use and impact of intra-aortic balloon pump on mortality in patients with acute myocardial infarction complicated by cardiogenic shock: results of the Euro Heart Survey on PCI

Preemptive Impella 5.5 insertion to reduce operative risk in high-risk cardiac surgery: A case report

INTRODUCTION AND IMPORTANCE

Society of thoracic surgery (STS) risk score has been used as a tool to gauge operative risk of cardiac surgery patients. High-risk patients, with STS risk score > 8 %, are considered as having prohibitive risk and are not offered surgery. There is no established strategy to minimize postoperative hemodynamic instability using mechanical circulatory support (MCS), despite growing interest in utilizing MCS prior to hemodynamic instability. The Impella 5.5 can provide enough perfusion and unload the left ventricle.

CASE PRESENTATION

We managed a 75-year-old male with multiple comorbidities and a presumed Society of Thoracic Surgeons (STS) score higher than 9.8 %, who had redo coronary artery bypass grafting and aortic and mitral valve replacement with concomitant implantation of the Impella 5.5. Patient had a good recovery despite developing post-operative atrial fibrillation.

DISCUSSION

Impella is used as a mechanical circulatory support device in patients with cardiogenic shock. It provides forward flow and effectively unloads the left ventricle. The concomitant placement of the Impella 5.5 in high-risk cardiac candidates may be associated with reduced operative risk.

CONCLUSION

Placement of the device as part of surgical plan can potentially mitigate the perioperative risk by providing adequate endogean perfusion, decrease pressor support, unloading LV.

Mathematical and Computational Modeling of Device-Induced Thrombosis

Given the extensive and routine use of cardiovascular devices, a major limiting factor to their success is the thrombotic rate that occurs. This both poses direct risk to the patient and requires counterbalancing with anticoagulation and other treatment strategies, contributing additional risks. Developing a better understanding of the mechanisms of device-induced thrombosis to aid in device design and medical management of patients is critical to advance the ubiquitous use and durability. Thus, mathematical and computational modelling of device-induced thrombosis has received significant attention recently, but challenges remain. Additional areas that need to be explored include microscopic/macroscopic approaches, reconciling physical and numerical timescales, immune/inflammatory responses, experimental validation, and incorporating pathologies and blood conditions. Addressing these areas will provide engineers and clinicians the tools to provide safe and effective cardiovascular devices.

Mechanical Circulatory Support in Acute Myocardial Infarction and Cardiogenic Shock

Mechanical circulatory support devices are increasingly used for the treatment of acute myocardial infarction complicated by cardiogenic shock. These devices provide different levels of univentricular and biventricular support, have different mechanisms of actions, and provide different physiologic effects. Institutions require expert teams to safely implant and manage these devices. This article reviews the mechanism of action, physiologic effects, and data as they relate to the utilization of these devices.

Patient and Device Selection for Hemodynamic Support in High-Risk Percutaneous Coronary Intervention

Coronary artery disease continues to advance resulting in the development of high-risk percutaneous interventions. This includes treatment of patients with multivessel disease, unprotected left main, acute myocardial infarction complicated by cardiogenic shock, and depressed left ventricular ejection fraction. As a result, mechanical circulatory support devices have evolved but require an understanding of patient hemodynamics, device mechanics, and access management. Trial data regarding device selection are limited by inclusion of cardiogenic shock patients, and observational studies are conflicted by selection bias, site familiarity with devices, and complication management; therefore, clinical judgment is required to treat high-risk patients appropriately.

Percutaneous Mechanical Circulatory Support Devices in Cardiogenic Shock

Despite a high rate of early revascularization and use of intra-aortic balloon pump counterpulsation therapy, the prognosis of patients with cardiogenic shock has remained poor. In the hopes of improving outcomes, clinicians are increasingly turning to percutaneous left and right mechanical circulatory support devices. Until recently, the evidence base for these devices had consisted only of observational data, meta-analyses, and small feasibility trials. In this article, we describe the contemporary outcomes of patients with cardiogenic shock, the hemodynamics of cardiogenic shock, and hemodynamic effects of percutaneous mechanical circulatory support devices. We then use this discussion to provide clinicians with a useful framework for understanding when selecting between or while managing patients with a percutaneous mechanical circulatory support devices. We critically review the recently published data for and against the use of commercially available devices-the intra-aortic balloon pump counterpulsation, the Impella system, the TandemHeart, and venous-arterial extracorporeal membrane oxygenation-and highlight gaps in our understanding. Given such gaps, a consensus multidisciplinary approach that combines expertise from interventional cardiologists, heart failure specialists, cardiac surgeons, and cardiac anesthesiologists may help pair the right patient with the right device at the right time.

Vasoactive Inotropic Score as a Predictor of Mortality in Adult Patients With Cardiogenic Shock: Medical Therapy Versus ECMO

INTRODUCTION AND OBJECTIVES

This study investigated whether the vasoactive inotropic score (VIS) is independently predictive of mortality in cardiogenic shock (CS).

METHODS

This study was retrospective, observational study. Patients who were admitted to the cardiac intensive care unit from January 2012 to December 2015 were screened, and 493 CS patients were finally enrolled. To quantify pharmacologic support, the patients were divided into 5 groups based on a quintile of VIS: 1 to 10, 11 to 20, 21 to 38, 39 to 85, and > 85. The primary outcome was in-hospital mortality.

RESULTS

In-hospital mortalities in the 5 VIS groups in increasing order were 8.2%, 14.1%, 21.1%, 32.0%, and 65.7%, respectively (P < .001). Multivariable analysis indicated that VIS ranges of 39 to 85 (aOR, 3.85; 95%CI, 1.60-9.22; P = .003) and over 85 (aOR, 10.83; 95%CI, 4.43-26.43; P < .001) remained significant prognostic predictors for in-hospital mortality. With multiple logistic regression to remove any confounding effects, we found that the localized regression lines regarding the odds of death intersected each other's (medical therapy alone and combined extracorporeal membrane oxygenation group) path at VIS = 130. In contrast to linear correlation between VIS and mortality for patients treated with medical therapy alone, there was little association between a VIS of 130 or more and the probability of in-hospital mortality for patients who were treated with extracorporeal membrane oxygenation.

CONCLUSIONS

A high level of vasoactive inotropic support during the first 48hours was significantly associated with increased in-hospital mortality in adult CS patients.

Clinical outcomes of patients undergoing primary percutaneous coronary intervention for acute myocardial infarction requiring the intensive care unit

Background

Outcomes for patients with ST-segment elevation myocardial infarction continue to improve, largely due to timely provision of reperfusion by primary percutaneous coronary intervention (PPCI). However, despite prompt and successful PPCI, a small proportion of patients require ventilatory and hemodynamic support in an intensive care unit (ICU). The outcome of these patients remains poorly defined.

Methods

A retrospective review of all consecutive admissions post-PPCI pathway to a single ICU between January 2009 and May 2014 was performed. Patients were analysed based on survival and indication for admission. Preadmission characteristics and ICU course were reviewed. Univariate and multivariable regression analysis was performed to determine predictors of outcome.

Results

During the study period 2902 PPCI were performed and 101 patients were admitted to ICU following PPCI (incidence 3.5%). ICU mortality post-PPCI was 33.7%. Pre-ICU admission factors in a multivariable logistic regression analysis associated with increased mortality included requirement for an intra-aortic balloon pump and a high SOFA score.

Conclusions

ICU admission post PPCI is associated with significant mortality. Mortality was related to high presenting SOFA score and need for IABP. These results provide important prognostic information and an acceptable method for risk-stratifying patients with acute myocardial infarction requiring intensive care.

Contemporary trends in cardiogenic shock: Incidence, intra-aortic balloon pump utilisation and outcomes from the London Heart Attack Group

Background:

Cardiogenic shock remains a major cause of morbidity and mortality in patients with ST-segment elevation myocardial infarction. We aimed to assess the current trends in cardiogenic shock management, looking specifically at the incidence, use of intra-aortic balloon pump therapy and outcomes in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention.

Methods and results:

We undertook an observational cohort study of 21,210 ST-segment elevation myocardial infarction patients treated between 2005–2015 at the eight Heart Attack Centres in London, UK. Patients’ details were recorded at the time of the procedure into local databases using the British Cardiac Intervention Society percutaneous coronary intervention dataset. There were 1890 patients who presented with cardiogenic shock. The primary outcome was all-cause mortality at a median follow-up of 4.1 years (interquartile range: 2.2–5.8 years). Increasing rates of cardiogenic shock were seen over the course of the study with consistently high mortality rates of 45–70%. A total of 685 patients underwent intra-aortic balloon pump insertion during primary percutaneous coronary intervention for cardiogenic shock with decreasing rates over time. Those patients undergoing intra-aortic balloon pump therapy were younger, more likely to have poor left ventricular function and less likely to have had previous percutaneous coronary intervention compared to the control group. Procedural success rates were similar (86.0% vs 87.1%, p=0.292) although crude, in-hospital major adverse cardiac event rates were higher (43.8% vs 33.7%, p<0.0001) in patients undergoing intra-aortic balloon pump therapy. Kaplan-Meier analysis demonstrated significantly higher mortality rates in patients receiving intra-aortic balloon pump therapy (50.9% intra-aortic balloon pump vs 39.9% control, p<0.0001) during the follow-up period. After multivariate Cox analysis (hazard ratio 1.04, 95% confidence interval 0.62–1.89) and the use of propensity matching (hazard ratio: 1.29, 95% confidence interval: 0.68–1.45) intra-aortic balloon pump therapy was not associated with mortality.

Conclusion:

Cardiogenic shock treated by percutaneous coronary intervention is increasing in incidence and remains a condition associated with high mortality and limited treatment options. Intra-aortic balloon pump therapy was not associated with a long-term survival benefit in this cohort and may be associated with increased early morbidity.

Percutaneous cardiac support during myocardial infarction drastically reduces mortality: perspectives from a swine model

BACKGROUND/AIMS

Acute myocardial infarction (AMI) with cardiogenic shock (CS) remains the leading cause of in-hospital death in acute coronary syndromes. In the AMI-CS pig model we tested the efficacy of temporary percutaneous cardiorespiratory assist device (PCRA) in rescuing the failing heart and reducing early mortality.

METHODS

In open-chest pigs we induced AMI by proximal left anterior descending coronary artery (LAD) ligation. Eight animals without PCRA (C group) were compared with 12 animals otherwise treated with PCRA (T group), starting approximately at 60 minutes post-occlusion and lasting 120-180 minutes. In 3 animals of the T group, regional myocardial oxygen content was also imaged by two-dimensional near infrared spectroscopy (2D-NIRS) with and without PCRA, before and after LAD reperfusion.

RESULTS

All animals without PCRA died despite unrelenting resuscitation maneuvers (120 minutes average survival time). Conversely, animals treated with PCRA showed a reduction in life-threatening arrhythmia and maintenance of aortic pressure, allowing interruption of PCRA in all cases early in the experiments, with sound hemodynamics at the end of the observation period. During LAD occlusion, NIRS showed severe de-oxygenation of the LAD territory that improved with PCRA. After PCRA suspension and LAD reperfusion, the residual de-oxygenated area proved to be smaller than the initial risk area.

CONCLUSIONS

In AMI, PCRA initiated during advanced CS drastically reduced early mortality from 100% to 0% in a 4-5 hour observation period. PCRA promoted oxygenation of the ischemic area during LAD occlusion. Results support the use of PCRA as first line of treatment in AMI-CS, improving myocardial rescue and short-term survival.

Impact of a cardiac intensivist on mortality in patients with cardiogenic shock

BACKGROUND

This study aimed to evaluate the association between high-intensity staffing by a dedicated cardiac intensivist and clinical outcomes in CS.

METHODS

We enrolled 2923 consecutive patients admitted to a cardiac care unit (CCU) from January 1, 2012 to December 31, 2015. In January 2013, the CCU changed from a low-intensity to high-intensity staffing unit managed by a dedicated cardiac intensivist. Patients were eligible if they required inotropes or vasopressors to maintain a systolic blood pressure>90mmHg, and had serum lactate≥2.0mmol/L. Eligible patients (n=513) were treated by low-intensity CCU (n=352) or high-intensity CCU (n=161). The primary outcome was CCU mortality.

RESULTS

CCU mortality occurred in 49 patients (30.6%) of the low-intensity group versus 62 patients (17.6%) of the high-intensity group (adjusted odds ratio [aOR] 0.44, 95% confidence interval [CI] 0.25-0.75, p<0.001). In-hospital mortality was not significantly different between the groups (33.1% vs 24.4%, aOR 0.75, 95% CI 0.43-1.29, p=0.29). Among 135 patients treated with extracorporeal membrane oxygenation, the high-intensity model was associated with lower CCU mortality (54.5% vs 22.5%, aOR 0.24, 95% CI 0.07-0.77, p=0.02) and in-hospital mortality (57.6% vs 29.4%, aOR 0.28, 95% CI 0.10-0.81, p=0.02).

CONCLUSION

High-intensity staffed CCU managed by a dedicated cardiac intensivist was associated with a significant reduction of CS-related mortality.

Impact of intra-aortic balloon pump on short-term clinical outcomes in ST-elevation myocardial infarction complicated by cardiogenic shock: A "real life" single center experience

OBJECTIVE

To analyze the use and impact of the intra-aortic balloon pump (IABP) upon the 30-day mortality rate and short-term clinical outcome of non-selected patients with ST-elevation acute myocardial infarction (acute STEMI) complicated by cardiogenic shock (CS).

DESIGN

A single-center retrospective case-control study was carried out.

SETTING

Coronary Care Unit.

PATIENTS

Data were collected from 825 consecutive patients with acute STEMI admitted to a Coronary Care Unit from January 2009 to August 2015. Seventy-three patients with CS upon admission subjected to emergency percutaneous coronary intervention (PCI) were finally included in the analysis and were stratified according to IABP use (44 patients receiving IABP).

VARIABLES

Cardiovascular history, hemodynamic situation upon admission, angiographic and procedural characteristics, and variables derived from admission to the Coronary Care Unit.

RESULTS

Cumulative 30-day mortality was similar in the patients subjected to IABP and in those who received conventional medical therapy only (29.5% and 27.6%, respectively; HR with IABP 1.10, 95% CI 0.38-3.11; p=0.85). Similarly, no significant differences were found in terms of the short-term clinical outcome between the groups: time on mechanical ventilation, days to hemodynamic stabilization, vasoactive drug requirements and stay in the Coronary Care Unit. Poorer renal function (HR 3.9, 95% CI 1.4-10.6; p=0.008), known peripheral artery disease (HR 3.3, 95% CI 1.2-9.1; p=0.019) and a history of diabetes mellitus (HR 3.2, 95% CI 1.2-8.1; p=0.018) were the only variables independently associated to increased 30-day mortality.

CONCLUSION

In our "real life" experience, IABP does not modify 30-day mortality or the short-term clinical outcome in patients presenting STEMI complicated with CS and subjected to emergency percutaneous coronary revascularization.

Efficacy of Intra-aortic Balloon Pump before versus after Primary Percutaneous Coronary Intervention in Patients with Cardiogenic Shock from ST-elevation Myocardial Infarction

BACKGROUND

Previous studies showed that patients with cardiogenic shock (CS) from ST-elevation acute myocardial infarction (STEMI) supported by intra-aortic balloon pump (IABP) before primary percutaneous coronary intervention (PCI) decreased the risk of in-hospital mortality than patients who received IABP after PCI. However, little evidence is available on the optimal order of IABP insertion and primary PCI. The aim of this study was to investigate the impact of the sequence of IABP support and PCI and its association with major adverse cardiac and cerebrovascular events (MACCEs).

METHODS

Data were obtained from 218 consecutive patients with CS due to STEMI in Beijing Anzhen Hospital between 2008 and 2014, who were treated with IABP and PCI. The patients were divided into two groups: Group A in whom IABP received before PCI (n = 106) and Group B in whom IABP received after PCI (n = 112). We evaluated the myocardial perfusion using myocardial blush grade and resolution of ST-segment elevation. The primary endpoint was 12-month risk of MACCE.

RESULTS

Most baseline characteristics were similar in patients between the two groups. However, patients received IABP before PCI were associated with a delay of door-to-balloon time (DBT) and higher troponin I level (P < 0.05). However, myocardial perfusion was significantly improved in patients treated with IABP before PCI (P < 0.05). Overall, IABP support before PCI was not associated with significantly lower risk of MACCE (P > 0.05). In addition, risk of all-cause mortality, bleeding, and acute kidney injury (AKI) was similar between two groups (P > 0.05). Multivariate analysis showed that DBT (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.1-4.8, P = 0.04), IABP support after PCI (OR 5.7, 95% CI 2.7-8.4, P = 0.01), and AKI (OR 7.4, 95% CI 4.9-10.8, P = 0.01) were the independent predictors of mortality at 12-month follow-up.

CONCLUSIONS

Early IABP insertion before primary PCI is associated with improved myocardial perfusion although DBT increases. IABP support before PCI does not confer a 12-month clinical benefit when used for STEMI with CS.

Acute Myocardial Infarction/Thrombectomy

This article focuses on specialized techniques and devices used in the most challenging cases of acute myocardial infarction. Areas where high-quality evidence is either clear or absent are avoided. Controversies in the use of support or thrombectomy devices, the addition of adjunct pharmacology, and the decision to treat nonculprit lesions are discussed. Recent years have seen a shift in guidelines to downgrading the use of assist devices in cardiogenic shock and aspiration thrombectomy, whereas consideration of nonculprit coronary intervention has been revived. These changes come in the wake of a series of large, practice-changing clinical trials.

Intra-Aortic Balloon Pump Counterpulsation during Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction and Cardiogenic Shock: Insights from the British Columbia Cardiac Registry

Background

Cardiogenic shock complicating ST-elevation myocardial infarction (STEMI) is associated with significant morbidity and mortality. In the primary percutaneous coronary intervention (PPCI) era, randomized trials have not shown a survival benefit with intra-aortic balloon pump (IABP) therapy. This differs to observational data which show a detrimental effect, potentially reflecting bias and confounding. Without robust and valid risk adjustment, findings from non-randomized studies may remain biased.

Methods

We compared long-term mortality following IABP therapy in patients with cardiogenic shock undergoing PPCI during 2008–2013 from the British Columbia Cardiac Registry. We addressed measured and unmeasured confounding using propensity score and instrumental variable methods.

Results

A total of 12,105 patients with STEMI were treated with PPCI during the study period. Of these, 700 patients (5.8%) had cardiogenic shock. Of the patients with cardiogenic shock, 255 patients (36%) received IABP therapy. Multivariable analyses identified IABP therapy to be associated with increased mortality up to 3 years (HR = 1.67, 95% CI:1.20–2.67, p<0.001). This association was lost in propensity-matched analyses (HR = 1.23, 95% CI: 0.84–1.80, p = 0.288). When addressing measured and unmeasured confounders, instrumental variable analyses demonstrated that IABP therapy was not associated with mortality at 3 years (Δ = 16.7%, 95% CI: -12.7%, 46.1%, p = 0.281). Subgroup analyses demonstrated IABP was associated with increased mortality in non-diabetics; patients not undergoing multivessel intervention; patients without renal disease and patients not having received prior thrombolysis.

Conclusions

In this observational analysis of patients with STEMI and cardiogenic shock, when adjusting for confounding, IABP therapy had a neutral effect with no association with long-term mortality. These findings differ to previously reported observational studies, but are in keeping with randomized trial data.

Usefulness of Intra-aortic Balloon Pump Counterpulsation

Intra-aortic balloon pump (IABP) counterpulsation is the most widely used mechanical circulatory support device because of its ease of use, low complication rate, and fast manner of insertion. Its benefit is still subject of debate, and a considerable gap exists between guidelines and clinical practice. Retrospective nonrandomized studies and animal experiments show benefits of IABP therapy. However, recent large randomized trials do not show benefit of IABP therapy, which has led to a downgrading in the guidelines. In our view, this dichotomy between trials and practice might be the result of insufficient understanding of the prerequisites needed for effective IABP therapy, that is, exhausted autoregulation, and of not including the right patient population in trials. The population included in recent large randomized trials has been heterogeneous, also including patients in whom benefit of IABP could not be expected. The clinical condition in which most benefit is expected, that is persistent ischemia in acute ST-elevation myocardial infarction, is discussed in this review. In conclusion, this review aims to explain the physiological principles needed for effective IABP therapy, to reflect critically on the large randomized trials, and to solve some of the controversies in this field.

Percutaneous assist devices in acute myocardial infarction with cardiogenic shock: Review, meta-analysis

AIM: To assess the impact of percutaneous cardiac support in cardiogenic shock (CS) complicating acute myocardial infarction (AMI), treated with percutaneous coronary intervention.

METHODS: We selected all of the studies published from January 1^st, 1997 to May 15^st, 2015 that compared the following percutaneous mechanical support in patients with CS due to AMI undergoing myocardial revascularization: (1) intra-aortic balloon pump (IABP) vs Medical therapy; (2) percutaneous left ventricular assist devices (PLVADs) vs IABP; (3) complete extracorporeal life support with extracorporeal membrane oxygenation (ECMO) plus IABP vs IABP alone; and (4) ECMO plus IABP vs ECMO alone, in patients with AMI and CS undergoing myocardial revascularization. We evaluated the impact of the support devices on primary and secondary endpoints. Primary endpoint was the inhospital mortality due to any cause during the same hospital stay and secondary endpoint late mortality at 6-12 mo of follow-up.

RESULTS: One thousand two hundred and seventy-two studies met the initial screening criteria. After detailed review, only 30 were selected. There were 6 eligible randomized controlled trials and 24 eligible observational studies totaling 15799 patients. We found that the inhospital mortality was: (1) significantly higher with IABP support vs medical therapy (RR = +15%, P = 0.0002); (2) was higher, although not significantly, with PLVADs compared to IABP (RR = +14%, P = 0.21); and (3) significantly lower in patients treated with ECMO plus IABP vs IABP (RR = -44%, P = 0.0008) or ECMO (RR = -20%, P = 0.006) alone. In addition, Trial Sequential Analysis showed that in the comparison of IABP vs medical therapy, the sample size was adequate to demonstrate a significant increase in risk due to IABP.

CONCLUSION: Inhospital mortality was significantly higher with IABP vs medical therapy. PLVADs did not reduce early mortality. ECMO plus IABP significantly reduced inhospital mortality compared to IABP.

The outcomes of intra-aortic balloon pump usage in patients with acute myocardial infarction: a comprehensive meta-analysis of 33 clinical trials and 18,889 patients

BACKGROUND

The effects of intra-aortic balloon pump (IABP) usage in patients with acute myocardial infarction remain controversial. This study sought to evaluate the outcomes of IABP usage in these patients.

METHODS

Medline, EMBASE, and other internet sources were searched for relevant clinical trials. The primary efficacy endpoints (in-hospital, midterm, and long-term mortality) and secondary endpoints (reinfarction, recurrent ischemia, and new heart failure in the hospital) as well as safety endpoints (severe bleeding requiring blood transfusion and stroke in-hospital) were subsequently analyzed.

RESULTS

Thirty-three clinical trials involving 18,889 patients were identified. The risk of long-term mortality in patients suffering from acute myocardial infarction was significantly decreased following IABP use (odds ratio [OR] 0.66, 95% confidence interval [CI]: 0.48-0.91, P=0.010). Both in-hospital and midterm mortality did not differ significantly between the IABP use group and no IABP use group (in-hospital: OR 0.87, 95% CI: 0.59-1.28, P=0.479; midterm: OR 1.12, 95% CI: 0.53-2.38, P=0.768). IABP insertion was not associated with the risk reduction of reinfarction, recurrent ischemia, or new heart failure. However, IABP use increased the risk of severe bleeding requiring blood transfusion (OR 2.05, 95% CI: 1.29-3.25, P=0.002) and stroke (OR 1.71, 95% CI: 1.04-2.82, P=0.035). In the thrombolytic therapy and cardiogenic shock subgroups, reduced mortality rates following IABP use were observed.

CONCLUSION

IABP insertion is associated with feasible benefits with respect to long-term survival rates in patients suffering from acute myocardial infarction, particularly those suffering from cardiogenic shock and receiving thrombolytic therapy, but at the cost of higher incidence of severe bleeding and stroke.

Intra-aortic Balloon Pump Therapy for Acute Myocardial Infarction: A Meta-analysis

IMPORTANCE

Intra-aortic balloon pump (IABP) therapy is a widely used intervention for acute myocardial infarction with cardiogenic shock. Guidelines, which previously strongly recommended it, have recently undergone substantial change.

OBJECTIVE

To assess IABP efficacy in acute myocardial infarction.

DATA SOURCES

Human studies found in Pubmed, Embase, and Cochrane libraries through December 2014 and in reference lists of selected articles. Search strings were "myocardial infarction" or "acute coronary syndrome" and "intra-aortic balloon pump" or "counterpulsation."

STUDY SELECTION

Randomized clinical trials (RCTs) and observational studies comparing use of IABP with no IABP in patients with acute myocardial infarction.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted the data, and risk of bias in RCTs was assessed using the Cochrane risk of bias tool. We conducted separate meta-analyses of the RCTs and observational studies. Data were quantitatively synthesized using random-effects meta-analysis.

MAIN OUTCOMES AND MEASURES

Thirty-day mortality.

RESULTS

There were 12 eligible RCTs randomizing 2123 patients. In the RCTs, IABP use had no statistically significant effect on mortality (odds ratio [OR], 0.96 [95% CI, 0.74-1.24]), with no significant heterogeneity among trials (I2 = 0%; P = .52). This result was consistent when studies were stratified by the presence (OR, 0.94 [95% CI, 0.69-1.28]; P = .69, I2 = 0%) or absence (OR, 0.98 [95% CI, 0.57-1.69]; P = .95, I2 = 17%) of cardiogenic shock. There were 15 eligible observational studies totaling 15 530 patients. Their results were mutually conflicting (heterogeneity I2 = 97%; P < .001), causing wide uncertainty in the summary estimate for the association with mortality (OR, 0.96 [95% CI, 0.54-1.70]). A simple index of baseline risk marker imbalance in the observational studies appeared to explain much of the heterogeneity in the observational data (R2meta = 46.2%; P < .001).

CONCLUSIONS AND RELEVANCE

Use of IABP was not found to improve mortality among patients with acute myocardial infarction in the RCTs, regardless of whether patients had cardiogenic shock. The observational studies showed a variety of mutually contradictory associations between IABP therapy and mortality, much of which was explained by the differences between studies in the balance of risk factors between IABP and non-IABP groups.

Clinical outcomes of the intra-aortic balloon pump for resuscitated patients with acute myocardial infarction complicated by cardiac arrest

BACKGROUND

The aim of this study was to investigate the clinical effects of intra-aortic balloon pump (IABP) in patients who received cardiopulmonary resuscitation (CPR) before procedure.

METHODS AND RESULTS

Between November 2005 and April 2014, 49,542 patients were enrolled in a prospective cohort study for acute myocardial infarction (AMI) in Korea (KAMIR). CPR was performed in 1700 patients with cardiac arrest. Patients were excluded from the study if they had not undergone a coronary angiogram, if extracorporeal membrane oxygenation or thrombolysis was performed, and if mechanical complications presented. The primary end point was 1-month all-cause mortality. A total of 883 patients in the IABP group and 476 in the control group were included. During the 1-month follow-up, all-cause death occurred in 749 patients (55.1%). The IABP group was predominantly male and had a higher prevalence of ST-segment elevation MI and a higher risk of coronary lesions including left main disease and three-vessel disease. Glycoprotein IIb/IIIa inhibitor was administered less in the non-IABP group. In the total population, the IABP group had worse outcomes in terms of mortality rates after multivariate analysis [hazard ratio (HR) 1.22, 95% confidence interval (CI) 1.02-1.47, p=0.034] without increasing the incidence of recurrent MI, stroke, and major bleeding. After propensity matching with a pair of 452 patients, no significant differences were observed in baseline characteristics or clinical outcomes (HR 1.21, 95% CI 0.93-1.57, p=0.158).

CONCLUSION

The use of IABP did not show clinical benefits in patients with AMI complicated by severe cardiogenic shock after propensity matching analysis.

Clinical and prognostic role of ammonia in advanced decompensated heart failure. The cardio-abdominal syndrome?

BACKGROUND

Advanced heart failure is associated with end-organ damage. Recent literature suggested an intriguing crosstalk between failing heart, abdomen and kidneys. Venous ammonia, as a by-product of the gut, could be a marker of abdominal injury in heart failure patients. The aim of the study was to investigate the clinical and prognostic role of ammonia in patients with advanced decompensated heart failure (ADHF).

METHODS & RESULTS

90 patients admitted with ADHF were prospectively studied. The prognostic role of ammonia at admission was evaluated. Primary end-points were: a composite of cardiac death, urgent heart transplantation and mechanical circulatory support at 3 months and need for renal replacement therapies (RRT). In the study cohort (age 59.0 ± 12.0 years, FE 21.6 ± 9.0%, INTERMACS profile 3.7 ± 0.9, creatinine 1.71 ± 0.95 mg/dl) 27 patients (30%) underwent the cardiac composite endpoint, while 9 patients (10%) needed RRT. At ROC curve analysis ammonia ≥ 130 μg/dl (abdominal damage) showed the best diagnostic accuracy. At multivariate analysis abdominal damage predicted the cardiac composite endpoint. Abdominal damage further increased risk among patient with cold profile at admission (HR 2.7, 95% CI 1.1-7.0, p = 0.046). At multivariate analysis abdominal damage also predicted need for RRT (OR 10.8, 95% CI 1.5-75.8, p = 0.017). The combined use of estimated right atrial pressure and ammonia showed the highest diagnostic accuracy and a very high specificity in prediction of need for RRT.

CONCLUSION

In a selected population admitted for ADHF ammonia, as a marker of abdominal derangement, predicted adverse cardiac events and need for RRT.

Intra-aortic balloon pump counterpulsation (IABP) for myocardial infarction complicated by cardiogenic shock

BACKGROUND

Intra-aortic balloon pump counterpulsation (IABP) is currently the most commonly used mechanical assist device for patients with cardiogenic shock due to acute myocardial infarction. Although there has been only limited evidence from randomised controlled trials, the previous guidelines of the American Heart Association/American College of Cardiology (AHA/ACC) and the European Society of Cardiology (ESC) strongly recommended the use of the IABP in patients with infarction-related cardiogenic shock on the basis of pathophysiological considerations, non-randomised trials and registry data. The recent guidelines downgraded the recommendation based on a meta-analysis which could only include non-randomised trials showing conflicting results. Up to now, there have been no guideline recommendations and no actual meta-analysis including the results of the large randomised multicentre IABP-SHOCK II Trial which showed no survival benefit with IABP support. This systematic review is an update of the review published in 2011.

OBJECTIVES

To evaluate, in terms of efficacy and safety, the effect of IABP versus non-IABP or other assist devices guideline compliant standard therapy on mortality and morbidity in patients with acute myocardial infarction complicated by cardiogenic shock.

SEARCH METHODS

Searches of CENTRAL, MEDLINE (Ovid) and EMBASE (Ovid), LILACS, IndMed and KoreaMed, registers of ongoing trials and proceedings of conferences were updated in October 2013. Reference lists were scanned and experts in the field contacted to obtain further information. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials on patients with acute myocardial infarction complicated by cardiogenic shock.

DATA COLLECTION AND ANALYSIS

Data collection and analysis were performed according to the published protocol. Individual patient data were provided for six trials and merged with aggregate data. Summary statistics for the primary endpoints were hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs).

MAIN RESULTS

Seven eligible studies were identified from a total of 2314 references. One new study with 600 patients was added to the original review. Four trials compared IABP to standard treatment and three to other percutaneous left assist devices (LVAD). Data from a total of 790 patients with acute myocardial infarction and cardiogenic shock were included in the updated meta-analysis: 406 patients were treated with IABP and 384 patients served as controls; 339 patients were treated without assisting devices and 45 patients with other LVAD. The HR for all-cause 30-day mortality of 0.95 (95% CI 0.76 to 1.19) provided no evidence for a survival benefit. Different non-fatal cardiovascular events were reported in five trials. During hospitalisation, 11 and 4 out of 364 patients from the intervention groups suffered from reinfarction or stroke, respectively. Altogether 5 out of 363 patients from the control group suffered from reinfarction or stroke. Reocclusion was treated with subsequent re-revascularization in 6 out of 352 patients from the intervention group and 13 out of 353 patients of the control group. The high incidence of complications such as moderate and severe bleeding or infection in the control groups has to be attributed to interventions with other LVAD. Possible reasons for bias were more frequent in small studies with high cross-over rates, early stopping and the inclusion of patients with IABP at randomisation.

AUTHORS' CONCLUSIONS

Available evidence suggests that IABP may have a beneficial effect on some haemodynamic parameters. However, this did not result in survival benefits so there is no convincing randomised data to support the use of IABP in infarct-related cardiogenic shock.

Influence of cardiogenic shock with or without the use of intra-aortic balloon pump on mortality in patients with ST-segment elevation myocardial infarction

Background

Cardiogenic shock is a serious complication of a ST-segment elevation myocardial infarction (STEMI). We compared short- and long-term mortality among (1) STEMI patients with and without cardiogenic shock and (2) STEMI patients with cardiogenic shock with and without the use of an intra-aortic balloon pump (IABP).

Methods

From January 1, 2002 to December 31, 2010, all patients presenting with STEMI and treated with primary percutaneous coronary intervention (PCI) were identified. The hazard ratio (HR) for death was estimated using a Cox regression model, controlling for potential confounding.

Results

The study cohort consisted of 4293 STEMI patients: 286 (6.7%) with and 4007 (93.3%) without cardiogenic shock. Compared with patients without cardiogenic shock, patients with cardiogenic shock were older, and more likely to have diabetes mellitus, multi-vessel disease, anterior myocardial infarction (MI) or bundle-branch block MI and a reduced creatinine clearance.

Among patients with cardiogenic shock vs. without shock, 30-day cumulative mortality was 57.3% vs. 4.5% (p < 0.001), one-year cumulative mortality was 60.7% vs. 8.2% (p < 0.001) and five-year mortality was 65.0% vs. 18.9% (p < 0.001). STEMI with cardiogenic shock was associated with higher 30-day mortality (adjusted HR = 12.89 [95% CI: 9.72–16.66]), 1-year mortality (adjusted HR = 8.83 [95% CI: 7.06–11.05]) and five-year mortality (adjusted HR = 6.39 [95% CI: 5.22–7.80]). IABP was used in 71 (25%) patients with cardiogenic shock and was associated with improved 30-day outcome (adjusted HR = 0.48 [95% CI: 0.28–0.83]).

Conclusion

Patients with STEMI and cardiogenic shock had substantial short- and long-term mortality that may be improved with IABP implantation. More studies on use of IABP in such patients are warranted.

Effects of intra-aortic balloon counterpulsation pump on mortality of acute myocardial infarction

Background

Several randomized controlled trials (RCTs) have evaluated the effect of intra-aortic balloon counterpulsation pump(IABP) on the mortality of acute myocardial infarction (AMI).

Objectives

To analyze the relevant RCT data on the effect of IABP on mortality and the occurrence of bleeding in AMI.

Data Sources

Published RCTs on the treatment of AMI by IABP were retrieved in searches of Medline, EMBASE, Cochrane and other related databases. The last search was conducted on July 20, 2014.

Study Eligibility Criteria

Randomized clinical trials comparing IABP to controls as treatment for AMI.

Participants

Patients with AMI.

Synthesis Methods

The primary endpoint was mortality, and the secondary endpoint was bleeding events. To account for to heterogeneity, a random-effects model was used to analyze the study data.

Results

Ten trials with a total population of 973 patients that were included in the analysis showed no significant difference in 2-month mortality between the IABP and the control groups. The 6-month mortality in the IABP group was not significantly lower than in the control group in the four RCTs that enrolled 59 AMI patients with CS. But in the four that enrolled AMI 66 patients without CS, the data showed opposite conclusion.

Conclusions

IABP cannot reduce within 2 months and 6–12 months mortality of AMI patients with CS as well as within 2 months mortality of AMI patients without CS, but can reduce 6–12 months mortality of AMI patients without CS. In addition, IABP can increase the risk of bleeding.

Impact of intra-aortic balloon pump on long-term mortality of unselected patients with ST-segment elevation myocardial infarction complicated by cardiogenic shock

Introduction

A large, randomised trial (IABP-SHOCK II) confirmed no benefit of intra-aortic balloon pump (IABP) on clinical outcomes of patients with ST-segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock. However, the ‘sickest’ patients are often excluded from randomised clinical trials, so it is difficult to generalise expected outcomes from randomized clinical trials to the real life setting.

Aim

We sought to evaluate the impact of IABP on 1-year mortality of unselected patients with STEMI presenting in cardiogenic shock.

Material and methods

Data were gathered for 1,650 consecutive patients with STEMI transferred for primary angioplasty from hospital networks in 7 countries in Europe from November 2005 to January 2007 (the EUROTRANSFER registry population). Of them, 51 patients with cardiogenic shock on admission were identified and stratified based on the use of IABP. Outcome results were adjusted for age and sex, to control possible selection bias.

Results

At the discretion of the operators, IABP was applied in 30 patients (58.8%, IABP group). The remaining 21 patients were treated without IABP (no-IABP group). The use of IABP was more frequent among males, younger patients, and patients with STEMI of the anterior wall. There was no difference in 30-day mortality in patients with and without IABP (no-IABP vs. IABP: 38.1% vs. 33.3%; adjusted OR 1.79 (95% CI 0.43–7.52); p = 0.43). Similarly, IABP had no impact on 1-year mortality (42.9% vs. 33.3%; adjusted OR 1.27 (95% CI 0.32–5.09); p = 0.74). One-year mortality was comparable among patients who survived hospitalisation (14.3% vs. 13%; p = 0.64).

Conclusions

We observed no benefit of IABP on short – and long-term mortality of unselected patients with STEMI complicated by cardiogenic shock.

Mechanical circulatory support

The role for temporary and durable mechanical circulatory support is rapidly expanding. As the use of these technologies continues to grow, the emergency physician has an increasing opportunity to participate in the advancement of these potentially life-saving technologies. This review discusses the current role of the intra-aortic balloon pump in cardiogenic shock, describes the complications and management strategies for the critically ill patient with a left ventricular assist device, and explores the emerging role of ECMO in the emergency department for patients presenting in refractory cardiogenic shock and cardiac arrest.

Early 'in-lab' use of levosimendan in patients with cardiogenic shock unsuitable for intra-aortic balloon pump counterpulsation

Intra-aortic balloon pump counterpulsation is currently the most used mechanical assistance device for patients with cardiogenic shock due to acute myocardial infarction. However, a recently published meta-analysis and trial failed to confirm previous knowledge. We report the results of four patients with ST elevation myocardial infarction, complicated by cardiogenic shock unsuitable for intra-aortic balloon pump counterpulsation treated with early levosimendan infusion during primary percutaneous coronary intervention.

Have we given up on intra-aortic balloon counterpulsation in post-myocardial infarction cardiogenic shock?

The recently published Intra-aortic Balloon Pump in Cardiogenic Shock II (IABP-SHOCK II) trial concluded that intra-aortic counterpulsation (IACP) does not reduce 30-day mortality in patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI) for whom early revascularization strategy was planned. The study resulted in downgrading IACP in post-AMI CS patients by certain professional organizations like the European Society of Cardiology. Although this is the largest and most important CS study of this decade, it suffers from considerable shortcomings: (1) time intervals from chest-pain onset or AMI recognition to revascularization, enrollment, and IACP initiation are not disclosed; (2) 86.6% of the treatment arm initiated IACP only post-percutaneous coronary intervention (PCI), and 4.3 % did not receive IACP at all; (3) 17.4% of the control arm crossed over to IACP or other mechanical support, mostly due to protocol violations; (4) there is no adjudication of the mortality events; (5) follow-up is limited to 30 days; and (5) both methodology (especially IACP device size) and quality of IACP are not evaluated and documented. Because the study assessed mostly the efficacy and safety of IACP initiated post-PCI, the study conclusions should not be extrapolated to IACP pre-PCI or during PCI in CS. Moreover, IACP had a favorable effect on the mortality of younger patients. Intra-aortic counterpulsation should remain the first line of mechanical circulatory support for the hemodynamically compromised AMI patients with or without CS who are undergoing primary PCI. Early upgrade to more advanced mechanical circulatory support should be considered for selective suitable candidates who remain in refractory CS despite revascularization and IACP.

Mechanical circulatory support in cardiogenic shock

Despite advances in coronary revascularization and widespread use of primary percutaneous interventions, cardiogenic shock complicating an acute ST-elevation myocardial infarction (CSMI) remains a clinical challenge with high mortality rates. Conservative management with catecholamines is associated with serious limitations, including arrhythmias, increased myocardial oxygen consumption, and inadequate circulatory support. Clinicians have therefore turned to mechanical means of circulatory support. Circulatory assist systems for CSMI can be distinguished by the method of placement (i.e. percutaneous vs. surgical), the type of circulatory support (i.e. left ventricular, right ventricular, or biventricular pressure and/or volume unloading), and whether they are combined with extracorporal membrane oxygenation (ECMO). The percutaneous assist systems most commonly used in CSMI are the intra-aortic balloon pump (IABP), venoarterial ECMO, the Impella pump, and the TandemHeart. Decades of clinical studies and experience demonstrated haemodynamic improvement, including elevation of diastolic perfusion pressure and cardiac output. Recently, the large randomized IABP-Shock II Trial did not show a significant reduction in 30-day mortality in CSMI with IABP insertion. There are no randomized study data available for ECMO use in CSMI. Both the Impella pump and the TandemHeart did not reduce 30-day mortality when compared with IABP in small randomized controlled trials (RCTs). In conclusion, despite the need for effective mechanical circulatory support in CSMI, current devices, as tested, have not been demonstrated to improve short- or long-term survival rates. RCTs testing the optimal timing of device therapy and optimal device design are needed to improve outcomes in CSMI.

The outcome of intra-aortic balloon pump support in acute myocardial infarction complicated by cardiogenic shock according to the type of revascularization: a comprehensive meta-analysis

AIMS

Despite the recommendations of the current guidelines, scientific evidence continue to challenge the effectiveness of intra-aortic balloon pump (IABP) in acute myocardial infarction (AMI) complicated by cardiogenic shock. Moreover, 2 recent meta-analyses showed contrasting results. The aim of this study is to test the effect of IABP according to the type of therapeutic treatment of AMI: percutaneous coronary intervention (PCI), thrombolytic therapy (TT), or medical therapy without reperfusion. Articles published from January 1, 1986, to December 31, 2012, were collected and analyzed by meta-analysis.

METHODS AND RESULTS

We evaluated the IABP impact on inhospital mortality, on safety end points (stroke, severe bleeding) and long-term survival, using risk ratio (RR) and risk difference (RD) estimates. We found that the risk of death was (i) not significantly different between the IABP and control groups (RR 0.95, P = .52; RD -0.04, P = .28), (ii) significantly reduced in the TT subgroup (RR 0.77, P < .0001; RD -0.16, P < .0001), and (iii) significantly increased in the PCI subgroup (RR 1.18, P = .01; RD 0.07, P = .01). There were no significant differences in secondary end points (P, not significant). In addition, we compared the meta-analyses collected over the same search period.

CONCLUSION

The results show that IABP support is significantly effective in TT reperfusion but is associated with a significant increase of the inhospital mortality with primary PCI. The comparison of the meta-analyses demonstrates the key role of analysing primary clinical treatments to avoid systematic errors.

[Ischaemic cardiogenic shock. Where do we stand in 2012?]

With a stable frequency (about 5% of acute coronary syndromes) and a mortality of nearly 45%, cardiogenic shock (CS), especially when it occurs in the immediate waning of myocardial infarction, still represents a therapeutic challenge. In this review, will be detailed the actual epidemiologic data of CS, its physiopathology and the different modalities of treatments available to the interventional cardiologist, especially the coronary revascularisation and the percutaneous left ventricular assistance, whether by intra-aortic balloon counterpulsation or by more complex systems.

Intra-aortic balloon pump in patients with acute myocardial infarction complicated by cardiogenic shock: results of the ALKK-PCI registry

AIMS

The recommendation for the use of the intra-aortic balloon pump (IABP) as adjunct in patients with cardiogenic shock undergoing primary PCI in current guidelines is controversial. We sought to investigate the use and impact of the outcome of IABP in current practice of percutaneous coronary interventions in Germany.

METHODS AND RESULTS

Between January 2006 and December 2011, a total of 55,008 consecutive patients with acute coronary syndromes undergoing PCI in 41 hospitals were enrolled into the prospective Arbeitsgemeinschaft Leitende Kardiologische Krankenhausärzte registry. Of these, 22,039 had STEMI and 32,969 had NSTEMI, and cardiogenic shock was observed in 1,435 (6.5 %) and 478 (1.4 %), respectively. Of the total of 1,913 patients with shock, 487 (25.5 %) were treated with IABP. In-hospital mortality with and without IABP was 43.5 and 37.4 %. In the multivariate analysis, the use of IABP was associated with a strong trend for an increased mortality (odds ratio 1.45, 95 % CI 1.15-1.84).

CONCLUSION

In the current clinical practice in Germany, IABP is used only in one quarter of patients with cardiogenic shock treated with primary PCI. We observed no benefit of IABP on outcome, which supports the findings of the randomized IABP-Shock II trial.

Successful high-risk percutaneous coronary intervention with the use of minimal extracorporeal circulation system

Minimal extracorporeal circulation (MECC) represents a contemporary system which integrates several advances in cardiopulmonary bypass technology in a single circuit. We challenged the efficacy of the MECC system to support the circulation in elective high-risk percutaneous coronary intervention (PCI). A 78-year-old patient with complex coronary disease who would have been otherwise rejected for interventional therapy underwent PCI with rotablation on MECC support. The MECC system provided hemodynamic support at a flow of 1.8 L min(-1) m(-2) while perfusion pressure was kept at a minimum of 70 mm Hg. This allowed for successful angioplasty of the left main stem and a chronically occluded right coronary artery, which otherwise produced significant hemodynamic compromise. This case illustrates that mechanical circulatory support with the MECC system could provide a stable environment and a "safety net" for carrying out complex percutaneous coronary intervention in high-risk patients.

What is the evidence for IABP in STEMI with and without cardiogenic shock?

Intraaortic balloon pump (IABP) is the most widely used left ventricular support device in a variety of indications. This review focuses on the current literature and discusses the evidence of IABP in ST-elevation myocardial infarction (STEMI) with and without cardiogenic shock. In high-risk STEMI patients without cardiogenic shock several randomized clinical trials have been performed. The majority of the studies could not demonstrate an efficacy benefit for IABP as adjunctive therapy in comparison to standard treatment alone. Hence, recent meta-analyses could not reveal diverging mortality rates at a higher incidence of stroke and major bleedings with IABP use independent of the type of reperfusion therapy. IABP in STEMI patients with cardiogenic shock is recommended according to current American College of Cardiology/American Heart Association (AHA/ACC) and European Society of Cardiology (ESC) guidelines. In recent meta-analyses, IABP in cardiogenic shock complicated by STEMI has been shown to be associated with decreased mortality. However, these beneficial effects are limited to patients treated with thrombolysis, whereas in patients undergoing mechanical revascularization IABP therapy is associated with an increase in mortality. Nevertheless, these data only arise from prospective and retrospective cohort studies, as up to date only one very small randomized clinical trial has been completed. In summary, in high-risk STEMI patients without cardiogenic shock, current data do not support the use of IABP and should only be considered as a standby and bailout strategy if patients develop haemodynamic instability. Current data on IABP in patients with cardiogenic shock complicated by STEMI are scarce and highly limited due to the nonrandomized design of previous trials. However, according to current AHA/ACC and ESC guidelines its use is recommended. Although recent meta-analyses challenge current AHA/ACC/ESC guidelines, adequately powered randomized studies are needed to elucidate the role of IABP in patients with acute myocardial infarction complicated by cardiogenic shock.