A systematic review and meta-analysis of intra-aortic balloon pump therapy in ST-elevation myocardial infarction: should we change the guidelines?

Withdrawing intra-aortic balloon pump support paradoxically improves microvascular flow

INTRODUCTION

The Intra-Aortic Balloon Pump (IABP) is frequently used to mechanically support the heart. There is evidence that IABP improves microvascular flow during cardiogenic shock but its influence on the human microcirculation in patients deemed ready for discontinuing IABP support has not yet been studied. Therefore we used sidestream dark field imaging (SDF) to test our hypothesis that human microcirculation remains unaltered with or without IABP support in patients clinically ready for discontinuation of mechanical support.

METHODS

We studied 15 ICU patients on IABP therapy. Measurements were performed after the clinical decision was made to remove the balloon catheter. We recorded global hemodynamic parameters and performed venous oximetry during maximal IABP support (1:1) and 10 minutes after temporarily stopping the IABP therapy. At both time points, we also recorded video clips of the sublingual microcirculation. From these we determined indices of microvascular perfusion including perfused vessel density (PVD) and microvascular flow index (MFI).

RESULTS

Ceasing IABP support lowered mean arterial pressure (74 ± 8 to 71 ± 10 mmHg; P = 0.048) and increased diastolic pressure (43 ± 10 to 53 ± 9 mmHg; P = 0.0002). However, at the level of the microcirculation we found an increase of PVD of small vessels <20 μm (5.47 ± 1.76 to 6.63 ± 1.90; P = 0.0039). PVD for vessels >20 μm and MFI for both small and large vessels were unaltered. During the procedure global oxygenation parameters (ScvO2/SvO2) remained unchanged.

CONCLUSIONS

In patients deemed ready for discontinuing IABP support according to current practice, SDF imaging showed an increase of microcirculatory flow of small vessels after ceasing IABP therapy. This observation may indicate that IABP impairs microvascular perfusion in recovered patients, although this warrants confirmation.

Shock in acute myocardial infarction: the Cape Horn for trials?

Despite therapeutic improvements, cardiogenic shock (CS) remains the most common cause of death in patients with acute myocardial infarction (AMI). In addition to percutaneous coronary intervention, inotropes, fluids, adjunctive medication, intra-aortic balloon counterpulsation, and also assist devices are widely used for treatment. However, currently, there is only limited evidence for any of the above treatments. This review will therefore outline the underlying causes, pathophysiology, and treatment of CS complicating AMI with major focus on interventional techniques and advancement of new therapeutical arsenals, both pharmacological and mechanical.

Treatment of cardiogenic shock with left ventricular assist device combined with cardiac resynchronization therapy: a case report

Cardiogenic shock has a poor prognosis with established treatment strategies. We report a 62 years old man with heart failure exacerbating into refractory cardiogenic shock successfully treated with the combination of a percutaneous left ventricular assist device (LVAD) and subacute cardiac resynchronization therapy (CRT) implantable cardioverter-defibrillator device (CRT-D).

Microvascular obstruction: underlying pathophysiology and clinical diagnosis

Successful restoration of epicardial coronary artery patency after prolonged occlusion might result in microvascular obstruction (MVO) and is observed both experimentally as well as clinically. In reperfused myocardium, myocytes appear edematous and swollen from osmotic overload. Endothelial cell changes usually accompany the alterations seen in myocytes but lag behind myocardial cell injury. Endothelial cells become voluminous, with large intraluminal endothelial protrusions into the vascular lumen, and together with swollen surrounding myocytes occlude capillaries. The infiltration and activation of neutrophils and platelets and the deposition of fibrin also play an important role in reperfusion-induced microvascular damage and obstruction. In addition to these ischemia-reperfusion-related events, coronary microembolization of atherosclerotic debris after percutaneous coronary intervention is responsible for a substantial part of clinically observed MVO. Microvascular flow after reperfusion is spatially and temporally complex. Regions of hyperemia, impaired vasodilatory flow reserve and very low flow coexist and these perfusion patterns vary over time as a result of reperfusion injury. The MVO first appears centrally in the infarct core extending toward the epicardium over time. Accurate detection of MVO is crucial, because it is independently associated with adverse ventricular remodeling and patient prognosis. Several techniques (coronary angiography, myocardial contrast echocardiography, cardiovascular magnetic resonance imaging, electrocardiography) measuring slightly different biological and functional parameters are used clinically and experimentally. Currently there is no consensus as to how and when MVO should be evaluated after acute myocardial infarction.

Transradial percutaneous coronary intervention in acute myocardial infarction

Although transradial coronary intervention is widely applied for percutaneous procedures, its safety in the setting of ST-segment elevation myocardial infarction (STEMI) is controversial. The benefit of transradial approach in terms of reducing access site complications is well documented. However, higher rate of procedural failure and longer procedural times reported by some authors raise concerns regarding its applicability in STEMI. Our aim was to review the safety and efficacy of transradial coronary intervention versus transfemoral intervention in acute ST-elevation myocardial infarction. This review focuses on key aspects of safety and efficacy: adverse ischemic and bleeding events, reperfusion times and radiation exposure.

Comparison of hospital mortality with intra-aortic balloon counterpulsation insertion before versus after primary percutaneous coronary intervention for cardiogenic shock complicating acute myocardial infarction

Primary percutaneous coronary intervention (PCI) and intra-aortic balloon pump counterpulsation (IABP) are established treatment modalities in acute myocardial infarction complicated by cardiogenic shock. We hypothesized that the insertion of the IABP before primary PCI might result in better survival of patients with cardiogenic shock compared to postponing the insertion to after primary PCI. We, therefore, retrospectively studied 48 patients who had undergone primary PCI with IABP because of cardiogenic shock complicating acute myocardial infarction (26 patients received the IABP before and 22 patients after primary PCI). No significant differences were present in the baseline clinical characteristics between the 2 groups. The mean number of diseased vessels was greater in the group of patients treated with the IABP before primary PCI (2.8 +/- 0.5 vs 2.3 +/- 0.7, p = 0.012), but the difference in the number of treated vessels was not significant. The peak creatine kinase and creatine kinase -MB levels were lower in patients treated with the IABP before primary PCI (median 1,077, interquartile range 438 to 2067 vs median 3,299, interquartile range 695 to 6,834, p = 0.047, and median 95, interquartile range 34 to 196 vs median 192, interquartile range 82 to 467, p = 0.048, respectively). In-hospital mortality and the overall incidence of major adverse cardiac and cerebrovascular events were significantly lower in the group of patients receiving the IABP before primary PCI (19% vs 59% and 23% vs 77%, p = 0.007 and p = 0.0004, respectively). Multivariate analysis identified renal failure (odds ratio 15.2, 95% confidence interval 3.13 to 73.66) and insertion of the IABP after PCI (odds ratio 5.2, 95% confidence interval 1.09 to 24.76) as the only independent predictors of in-hospital mortality. In conclusion, the results of the present study suggest that patients with cardiogenic shock complicating acute myocardial infarction who undergo primary PCI assisted by IABP have a more favorable in-hospital outcome and lower in-hospital mortality than patients who receive IABP after PCI.

Adjunct therapy in STEMI intervention

ST-elevation myocardial infarction (STEMI) interventions have significantly reduced mortality and morbidity from acute myocardial infarction. Compulsive management of thrombus is a fundamental requirement of these interventions. A pragmatic thrombus-guided management strategy is reviewed along with additional novel therapeutic adjuncts for STEMI interventions.

Emerging drugs for acute myocardial infarction

IMPORTANCE OF THE FIELD

The present review is aimed at going over the pharmacological profile (and the clinical impact) of the emerging drugs involved in the management of patients with ST-elevation myocardial infarction (STEMI) in order to provide the cardiologists who deal with these patients in the early phase with the most recent evidence on this topic.

AREAS COVERED IN THIS REVIEW

Anticoagulant and antiplatelet drugs are the main cornerstones of therapy in the treatment of STEMI patients undergoing primary percutaneous coronary intervention (PCI). The main issues that clinicians have to deal with are represented by balancing thrombotic and bleeding risks. In tailoring therapy, variables such as age, sex and previous disease should be taken into account, as well as ongoing complications (such as acute renal failure) that could affect hemostasis. Despite the well-established clinical benefits of antiplatelet agents, questions remain, mainly surrounding potential for variable platelet response, which are strictly related to non-genetic (i.e., diet, drug-drug interaction, clinical factors such as obesity, diabetes mellitus, and inflammation) and genetic determinants.

WHAT THE READER WILL GAIN

In their daily practice, cardiologists cannot abstract from the knowledge and updating on the ongoing research fields as well as the newly developed drugs, which they should frame in the very patient in the attempt to the develop a personalized medical strategy. These include also the pharmacological option(s) in the treatment of the reperfusion injury, the metabolic aspects and the stem cell therapy. TAKE HOME MASSAGE: In our opinion, the goal of ongoing research on the pharmacological approach to STEMI patients is a personalized medical strategy that relies on critical clinicians who merge newly developed acquisitions on this topic and a more complete, systemic and critical approach to the patient.

The balloon pump-assisted coronary intervention study (BCIS-1): rationale and design

Several observational studies have suggested that mortality and major complications after high-risk percutaneous coronary intervention (PCI) can be reduced by elective insertion of an intra-aortic balloon pump (IABP). However, to date, this assertion has never been tested in a randomized trial, and as such, international guidelines do not provide formal recommendations for IABP use in this setting. The BCIS-1 is a randomized trial that addresses the hypothesis that elective IABP insertion before high-risk PCI will reduce major adverse cardiac and cerebrovascular events (MACCEs) at hospital discharge or 28 days after index PCI, whichever occurs sooner. High risk is defined by the presence of severe left ventricular dysfunction as well as a large amount of myocardium at risk. Patients who are in cardiogenic shock, have a class I indication for IABP use, or have an absolute contraindication to IABP use will be excluded. Three hundred eligible patients will be randomized to receive elective IABP insertion or no planned IABP insertion. The findings of BCIS-1 are expected to define the role of balloon counterpulsation in high-risk PCI. Confirmation of the efficacy of elective IABP use may prompt review of the international guidelines, which are currently very restricted. In contrast, a neutral or adverse outcome with elective counterpulsation in these high-risk patients will allow evidence-based rationalization of the current disparity between guidelines and the frequent real-world use of elective IABP support.

Transradial versus transfemoral percutaneous coronary intervention in acute myocardial infarction Systematic overview and meta-analysis

BACKGROUND

Although transradial percutaneous coronary intervention (TRPCI) is widely applied for percutaneous procedures, its safety in the setting of ST-segment elevation (STEMI) is controversial. Our aim was to assess the safety and efficacy of TRPCI versus transfemoral PCI in the context of treating patients suffering acute myocardial infarction with STEMI.

METHODS

Randomized, case-control, and cohort studies comparing access-related complications were analyzed. Our objective was to determine if radial access reduces major bleeding and thereby reduces death and ischemic events compared to femoral access in this setting. A fixed-effects model was used with random effects for sensitivity analysis.

RESULTS

Twelve studies involving 3324 patients were identified. Transradial PCI reduced major bleeding compared to transfemoral PCI (P = .0001), and significant reductions were found in the composite of death, myocardial infarction, or stroke (P = .001). Mortality reduction showed a significant toward benefit in the case of TRPCI (2.04% vs 3.06%, OR 0.54 [95% CI 0.33-0.86], P = .01). The fluoroscopic time was longer, and access site crossover was more frequent for TRPCI (P = .001, P < .00001, respectively).

CONCLUSIONS

Transradial PCI reduces the risk of periprocedural major bleeding and major adverse events in the STEMI setting.

Usefulness of intra-aortic balloon pump counterpulsation in patients with cardiogenic shock from acute myocardial infarction

Although intra-aortic balloon pump (IABP) counterpulsation is increasingly being used for the treatment of patients with cardiogenic shock from acute myocardial infarction, data on the long-term outcomes are lacking. The aim of the present study was to evaluate the 30-day and long-term mortality and to identify predictors for 30-day and long-term all-cause mortality of patients with acute myocardial infarction complicated by cardiogenic shock who were treated with IABP. From January 1990 to June 2004, 300 consecutive patients treated with IABP were included. The mean age of the study population was 61 +/- 11 years, and 79% of the patients were men. The survival rate until IABP removal after successful hemodynamic stabilization was 70% (n = 211). The overall cumulative 30-day survival rate was 58%. The 30-day mortality rate decreased over time from 52% in 1990 to 1994 to 36% in 2000 to 2004 (p for trend <0.05). Follow-up ranged from 0 to 15 years. In patients who survived until IABP removal, the cumulative 1-, 5-, and 10-year survival rate was 69%, 58%, and 36%, respectively. The adjusted predictors of long-term mortality were arrhythmias during the intensive cardiac care unit stay (hazard ratio [HR] 1.8, 95% confidence interval [CI] 1.2 to 2.9) and renal failure during the intensive cardiac care unit stay (HR 2.5, 95% CI 1.3 to 5.1). After adjustment, treatment with primary percutaneous coronary intervention (HR 0.5, 95% CI 0.3 to 0.9) and coronary artery bypass grafting (HR 0.4, 95% CI 0.2 to 0.8) were associated with lower long-term mortality. In conclusion, in patients with acute myocardial infarction complicated by cardiogenic shock treated with IABP, the 30-day survival improved with time and an encouraging number of patients survived in the long term.

Cellular responses to mild heat stress

Since its discovery in 1962 by Ritossa, the heat shock response has been extensively studied by a number of investigators to understand the molecular mechanism underlying the cellular response to heat stress. The most well characterized heat shock response is induction of the heat shock proteins that function as molecular chaperones and exert cell cycle regulatory and anti-apoptotic activities. While most investigators have focused their studies on the toxic effects of heat stress in organisms such as severe heat stress-induced cell cycle arrest and apoptosis, the cellular response to fever-ranged mild heat stress has been rather underestimated. However, the cellular response to mild heat stress is likely to be more important in a physiological sense than that to severe heat stress because the body temperature of homeothermic animals increases by only 1-2 degrees C during febrile diseases. Here we provide information that mild heat stress does have some beneficial role in organisms via positively regulating cell proliferation and differentiation, and immune response in mammalian cells.

New approaches to therapy of cancers of the stomach, colon and pancreas based on peptide analogs

Cancers of the stomach, colon and exocrine pancreas are major international health problems and result in more than a million deaths worldwide each year. The therapies for these malignancies must be improved. The effects of gastrointestinal (GI) hormonal peptides and endogenous growth factors on these cancers were reviewed. Some GI peptides, including gastrin and gastrin-releasing peptide (GRP) (mammalian bombesin), appear to be involved in the growth of neoplasms of the GI tract. Certain growth factors such as insulin-like growth factor (IGF)-I, IGF-II and epidermal growth factor and their receptors that regulate cell proliferation are also implicated in the development and progression of GI cancers. Experimental investigations on gastric, colorectal and pancreatic cancers with analogs of somatostatin, antagonists of bombesin/GRP, antagonists of growth hormone-releasing hormone as well as cytotoxic peptides that can be targeted to peptide receptors on tumors were summarized. Clinical trials on peptide analogs in patients with gastric, colorectal and pancreatic cancers were reviewed and analyzed. It may be possible to develop new approaches to hormonal therapy of GI malignancies based on various peptide analogs.