Percutaneous transluminal coronary angioplasty improves survival in acute myocardial infarction complicated by cardiogenic shock

Current spectrum and outcomes of infarct-related cardiogenic shock: insights from the CULPRIT-SHOCK registry and randomized controlled trial

AIMS

We analysed consecutive patients with acute myocardial infarction complicated by cardiogenic shock (CS) who were enrolled into the CULPRIT-SHOCK randomized controlled trial (RCT) and those with exclusion criteria who were included into the accompanying registry.

METHODS AND RESULTS

In total, 1075 patients with infarct-related CS were screened for CULPRIT-SHOCK in 83 specialized centres in Europe; 369 of them had exclusion criteria for the RCT and were enrolled into the registry. Patients were followed over 1 year. The mean age was 68 years and 260 (25%) were women. 13.5%, 30.9%, and 55.6% had one-vessel, two-vessel, and three-vessel coronary artery disease (CAD), respectively. Significant left main (LM) coronary artery stenosis was present in 8.0%. 54.2% of the patients had cardiac arrest before admission. Thrombolysis in myocardial infarction (TIMI) 3 patency of the infarct vessel after percutaneous coronary intervention was achieved in 83.6% of all patients. Mechanical circulatory support was applied in one-third of patients. Total mortality after 30 days and 1 year was 47.6% and 52.9%. Mortality after 1 year was highest in patients with LM coronary artery stenosis (63.5%), followed by three-vessel (56.6%), two-vessel (49.8%), and one-vessel CAD (38.6%), respectively. Mechanical complications were rare (21/1008; 2.1%) but associated with a high mortality of 66.7% after 1 year.

CONCLUSION

In specialized centres in Europe, short- and long-term mortality of patients with infarct-related CS treated with an invasive strategy is still high and mainly depends on the extent of CAD. Therefore, there is still a need for improvement of care to improve the prognosis of infarct-related CS.

2023 American Heart Association Focused Update on Adult Advanced Cardiovascular Life Support: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

Cardiac arrest is common and deadly, affecting up to 700 000 people in the United States annually. Advanced cardiac life support measures are commonly used to improve outcomes. This "2023 American Heart Association Focused Update on Adult Advanced Cardiovascular Life Support" summarizes the most recent published evidence for and recommendations on the use of medications, temperature management, percutaneous coronary angiography, extracorporeal cardiopulmonary resuscitation, and seizure management in this population. We discuss the lack of data in recent cardiac arrest literature that limits our ability to evaluate diversity, equity, and inclusion in this population. Last, we consider how the cardiac arrest population may make up an important pool of organ donors for those awaiting organ transplantation.

Effects of using primary percutaneous coronary interventions on the incidence of new-onset atrial fibrillation following an acute myocardial infarction

BACKGROUND

Acute ST-segment elevation myocardial infarction (STEMI) and new-onset atrial fibrillation (AF) are associated with increased risk of mortality.

HYPOTHESIS

This study aimed to determine the proportion of patients who go on to develop new-onset a AF after undergoing a primary or delayed percutaneous coronary intervention (PCI) for an acute STEMI and to explore possible risk factors.

METHODS

One hundred and fifty-four patients who underwent PCI after STEMI were included in the study. Patient characteristics, baseline blood tests and cardiac parameters, type of PCI, and incidence of new-onset AF within 3 months of PCI were recorded and analyzed.

RESULTS

Fifteen developed new-onset AF following the PCI, and 139 patients maintained a sinus rhythm. Univariate analysis showed significant differences between the two patient groups in terms of age, nature of the PCI (primary vs. delayed), left atrial diameter, and left ventricular diastolic dysfunction (p < .05). Age (odds ratio [OR] = 1.065, 95% confidence interval [CI]: 1.007-1.127, p < .05) and left atrial diameter (OR = 1.165, 95% CI: 1.008-1.347, p < .05), were independent predictors of new-onset AF after PCI. Primary PCI (OR = 0.232, 95% CI: 0.066-0.814, p < .05) was an independent protective factor.

CONCLUSION

Age and left atrial diameter were independent risk factors of new-onset AF in patients undergoing a PCI following an acute myocardial infarction, while primary PCI was a protective factor. This discovery can help reduce mortality rate, improve long-term prognosis, and provide a theoretical basis for the prevention of new-onset AF.

Outcomes of mechanical circulatory support for acute myocardial infarction complicated by cardiogenic shock

BACKGROUND

Mechanical circulatory support (MCS) with the Impella device (Abiomed, Danvers, MA) has been associated with higher in-hospital mortality than intra-aortic balloon pump (IABP) in the Premier Healthcare Database and National Cardiovascular Data Registry.

METHODS

The objective of this retrospective cohort study was to describe trends and outcomes of Impella usage in acute myocardial infarction complicated by cardiogenic shock (AMICS) treated with MCS (Impella or IABP) using real-world observational data from the National Inpatient Sample (NIS) including hospitalizations for AMICS managed with MCS between January 2012 to December 2017. The primary outcomes included in-hospital mortality, transfusion, acute kidney injury, stroke, total costs, and length of stay. Propensity score matching was performed with hierarchical models using risk factor and Elixhauser comorbidity variables.

RESULTS AND CONCLUSION

We identified 54,480 hospitalizations for AMICS managed with MCS including 5750 (10.5%) utilizing Impella. Throughout the study period, Impella usage increased yearly to 19.9% of AMICS cases in 2017. After propensity score matching, Impella was associated with higher in-hospital mortality (odds ratio [OR] 1.74, 95% confidence interval [CI] 1.41-2.13) and transfusions (OR 1.97, 95% CI 1.40-2.78) than IABP, without association with acute kidney injury or stroke. Impella use was associated with higher hospital costs (mean difference $22,416.80 [95% CI $17,029-27,804]). Impella usage for AMICS increased significantly from 2012 to 2017 and was associated with increased in-hospital mortality and costs. Randomized controlled trials are urgently needed to assess the safety and efficacy of Impella.

Mechanical Circulatory Support Following Out-of-Hospital Cardiac Arrest: Insights From the National Cardiogenic Shock Initiative

BACKGROUND

Evidence is limited regarding the role of mechanical circulatory support (MCS) in patients with acute coronary syndromes (ACS) complicated by cardiogenic shock (CGS). In particular, the role of MCS in patients with out-of-hospital cardiac arrest (OHCA) is unknown.

METHODS

The National Cardiogenic Shock Initiative (NCSI) is a multicenter United States registry of patients with ACS complicated by CGS treated with MCS. We compared the rate of survival to hospital discharge among patients with OHCA, in-hospital cardiac arrest (IHCA), or no cardiac arrest. We subsequently used multivariable analyses to determine independent predictors of OHCA survival.

RESULTS

Survival to hospital discharge occurred in 85.7% (42/49) of OHCA, 72.4% (50/69) of IHCA, and 74.5% (111/149) of non-cardiac arrest patients. By multivariable analysis, pre-procedural predictors of survival included younger age, female sex, fewer diseased vessels, left anterior descending coronary artery culprit, lower troponin, higher lactate, and delayed initiation of MCS. Procedural and post-procedural predictors of survival included fewer vessels treated, complete revascularization, higher post-MCS cardiac power output, and fewer inotropic medications required.

CONCLUSIONS

This study demonstrates that excellent outcomes may be achieved following OHCA when MCS is employed for patients appropriately selected by prognostic demographic, anatomic, and health status characteristics. A larger study population, currently being enrolled, is needed to validate the observation further.

The science of safety: complications associated with the use of mechanical circulatory support in cardiogenic shock and best practices to maximize safety

Acute mechanical circulatory support (MCS) devices are widely used in cardiogenic shock (CS) despite a lack of high-quality clinical evidence to guide their use. Multiple devices exist across a spectrum from modest to complete support, and each is associated with unique risks. In this review, we summarize existing data on complications associated with the three most widely used acute MCS platforms: the intra-aortic balloon pump (IABP), Impella systems, and veno-arterial extracorporeal membrane oxygenation (VA-ECMO). We review evidence from available randomized trials and highlight challenges comparing complication rates from case series and comparative observational studies where a lack of granular data precludes appropriate matching of patients by CS severity. We further offer a series of best practices to help shock practitioners minimize the risk of MCS-associated complications and ensure the best possible outcomes for patients.

In-hospital mortality of patients with cardiogenic shock after acute myocardial infarction; impact of early revascularization

OBJECTIVES

The purpose of this study was to determine the frequency of in-hospital mortality in 351 patients who developed cardiogenic shock after acute myocardial infarction and by determining this; we might find that how efficiently we could manage this serious condition in our population by knowing the factors which are associated with high mortality after cardiogenic shock. Moreover impact of early revascularization like thrombolytic therapy or angioplasty was also evaluated.

RESULTS

Mean age was 65.41 ± 7.78 years in our study. In-hospital mortality with cardiogenic shock after acute myocardial infarction was found to be 44.73%. Significant association of in-hospital mortality was noted with age, hypertension, diabetes mellitus and BMI. Patients receiving early revascularization were noted to have lower in-hospital mortality compared to those in whom revascularization was not done due to delayed presentation. This study concluded that there is a high frequency (44.73%) of in-hospital mortality in patients with cardiogenic shock after acute myocardial in our population. So, we recommend that for achieving a good outcome and to reduce in-hospital mortality; in addition to rapid diagnosis of this condition, underlying risk factors like hypertension and diabetes should be evaluated and managed accordingly and early revascularization should be done when possible.

Analysis of outcomes for 15,259 US patients with acute myocardial infarction cardiogenic shock (AMICS) supported with the Impella device

BACKGROUND

The Impella percutaneous ventricular assist device (PVAD) rapidly deploys mechanical circulatory support (MCS) in patients with acute myocardial infarction complicated by cardiogenic shock (AMICS). We present findings from a quality improvement (IQ) registry for US patients with AMICS who received Impella devices.

METHODS AND RESULTS

From January 2009 to December 2016, 46,949 patients from 1010US hospitals were entered into the IQ registry; of these, 15,259 had AMICS. Limited de-identified patient information, product performance, and survival to explantation were recorded. Of those with AMICS, 51% survived to explantation of PVAD. There was a significant difference between survival at explantation with quintile volume at hospitals (range: 0-100%; 30% survival rate in lowest quintile vs. 76% in top quintile; P<.0001). Use of the Impella device as first-line treatment pre-PCI was associated with a 59% survival rate, compared with 52% when used as a salvage strategy (P<.001). The survival rate among those who received hemodynamic monitoring with pulmonary artery catheters was 63% as compared with 49% in those who did not (P<.0001). Overall institutional Impella volume was related to survival (56% survival at sites with >7/year vs. 51% at sites with ≤1; P<.001).

CONCLUSIONS

In this early clinical experience with Impella support for AMICS, wide variation in outcomes existed across centers. Survival was higher when Impella was used as first support strategy, when invasive hemodynamic monitoring was used, and at centers with higher Impella implantation volume.

In-hospital outcomes of acute myocardial infarction with cardiogenic shock caused by right coronary artery occlusion vs. left coronary artery occlusion

In-hospital outcomes of acute myocardial infarction (AMI) with cardiogenic shock (CS) were still not satisfactory even in the primary percutaneous coronary intervention (PCI) era. The aim of this study was to compare in-hospital outcomes of AMI with CS caused by right coronary artery (RCA) occlusion vs. left coronary artery (LCA) occlusion. Consecutive 894 AMI patients from January 2010 to March 2015 were screened for inclusion. A total of 114 AMI patients with CS were included as the final study population, and were divided into the RCA group (n = 56) and LCA group (n = 58). The patient characteristics were compared between the two groups. Multivariate logistic regression analysis was performed to show whether the RCA group was associated with better outcomes even after controlling confounding factors. In-hospital mortality was significantly lower in the RCA group (8.9%) than in the LCA group (46.6%) (P < 0.001). The RCA group (vs. the LCA group) was inversely associated with in-hospital death (OR 0.08, 95% CI 0.02-0.21, P < 0.001) after controlling covariates. Aspartate transaminase value (per 50 U/L incremental: OR 1.22, 95% CI 1.03-1.45, P = 0.02), aging (per 10-year-old incremental: OR 2.14, 95% CI 1.26-3.63, P = 0.01) and using VA-ECMO (OR 22.13, 95% CI 5.22-93.90, P < 0.001) were also significantly associated with in-hospital death. In conclusion, among AMI patients with CS, IRA of RCA was significantly associated with the better in-hospital outcome.

Experimental and mathematical studies on the drug release properties of aspirin loaded chitosan nanoparticles

The study of drug release dynamic is aiming at understanding the process that drugs release in human body and its dynamic characteristics. It is of great significance since these characteristics are closely related to the dose, dosage form, and effect of the drugs. The Noyes-Whitney function is used to represent how the solid material is dissolved into solution, and it is well used in study of drug dynamic. In this research, aspirin (acetylsalicylic acid (ASA)) has been encapsulated with different grades of chitosan (CS) varying in molecular weight (Mw) for the purpose of controlled release. The encapsulation was accomplished by ionic gelation technology based on assembly of positively charged chitosan and negatively charged sodium tripolyphosphate (TPP). The encapsulation efficiency, loading capacity, and drug release behavior of aspirin loaded chitosan nanoparticles (CS-NPs) were studied. It was found that the concentration of TPP and Aspirin, molecular weights of chitosan have important effect on the drug release patterns from chitosan nanoparticles. The results for simulation studies show that the Noyes-Whitney equation can be successfully used to interpret the drug release characteristics reflected by our experimental data.

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

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

Percutaneous coronary intervention in cardiogenic shock complicating acute ST-elevation myocardial infarction-a single centre experience

BACKGROUND

Mortality in acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) approaches 70 - 80%, regardless of the type of pharmacological treatment. Early revascularisation improves survival in AMI with CS. Our aim is to assess the predictors of mid-term outcome after percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) and CS.

METHODS

Forty-one patients who underwent primary or rescue PCI for CS were analysed comparing their baseline, angiographic, PCI data, 30-day and 1-year survival.

RESULTS

There were no significant differences between survivors and non-survivors in baseline characters, except for more number of transfer admissions (P= 0.0005), and cardiopulmonary resuscitations (P= 0.015) in the later group. The mean time between myocardial infarction (MI) onset to shock and MI onset to revascularisation were 12.8 ± 12.9 hours and 17.0 ± 16.8 hours, respectively. Patients with better pre-procedure thrombolysis in myocardial infarction (TIMI) flow in the infarct-related artery (IRA) had better survival (P= 0.0005). Successful PCI was achieved in 48.8% of patients. The 30-day mortality was 56.1% and all were prior to hospital discharge. Patients with successful PCI had better short-term survival in comparison with patients with failed PCI (80% vs 9.6%). Eighteen patients who survived at 30 days were followed up for 12-72 months (mean 28.5 ± 5.4 months). Fifteen patients survived at 1 year after PCI and all were in good functional status.

CONCLUSION

Mortality remains high even with PCI. Achieving IRA patency with TIMI 3 flow is the main determinant of survival. Survival and functional status are good in patients who are discharged from hospital.

A review of cardiogenic shock in acute myocardial infarction

Cardiogenic shock continues to be the most common cause of death in patients hospitalized with acute myocardial infarction. It has also been frequently associated with ST-segment elevation myocardial infarction (STEMI) and patients with co-morbidities. Cardiogenic shock presents with low systolic blood pressure and clinical signs of hypoperfusion. Rapid diagnosis and supportive therapy in the form of medications, airway support and intra-aortic balloon counterpulsation is required. Initial stabilization can be followed by reperfusion by fibrinolytic therapy, emergent percutaneous intervention (PCI) or coronary artery bypass grafting (CABG). The latter two have been found to decrease mortality in the long term. Research is being carried out on the role of inflammatory mediators in the clinical manifestation of cardiogenic shock. Mechanical support devices also show promise in the future.

Post myocardial infarction cardiogenic shock: a review of current therapies

Cardiogenic shock is often a devastating consequence of acute myocardial infarction (MI) and portends to significant mortality and morbidity. Despite improvements in expediting the time to treatment and enhancements in available medical therapy and reperfusion techniques, cardiogenic shock remains the most common cause of mortality following MI. Post-MI cardiogenic shock most commonly occurs as a consequence of severe left ventricular dysfunction. Right ventricular (RV) MI must also be considered. Mechanical complications including acute mitral regurgitation, ventricular septal rupture, and ventricular free-wall rupture can also lead to cardiogenic shock. Rapid diagnosis of cardiogenic shock and its underlying cause is pivotal to delivering definitive therapy. Intravenous vasoactive agents and mechanical support devices may temporize the patient's hemodynamic status until definitive therapy by percutaneous or surgical intervention can be performed. Despite prompt management, post-MI cardiogenic shock mortality remains high.

Early revascularization is beneficial across all ages and a wide spectrum of cardiogenic shock severity: A pooled analysis of trials

BACKGROUND

A pooled analysis in cardiogenic shock due to acute coronary syndromes is desirable to assess the effect of early revascularization (ERV) across all ages and a wide spectrum of disease severity.

METHODS

Only two randomized controlled trials (RCT), i.e. SMASH and SHOCK, met the inclusion criteria and were combined for a pooled analysis using individual patient data (n = 348).

RESULTS

SMASH patients (n = 54, 16%) had more severe disease than SHOCK patients (n = 294, 84%). After adjustment for age, anoxic brain damage, non-inferior myocardial infarction, prior coronary artery bypass graft surgery, renal failure, systolic blood pressure, and selection for coronary angiography, one-year mortality was similar (relative risk SHOCK versus SMASH 0.87, 95% CI: 0.61-1.25). Relative risk of one-year death for ERV versus initial medical stabilization was 0.82 (95% CI: 0.70-0.96). There was no significant difference in the treatment effect by age (≤75 years relative risk at one year 0.79, 95% CI: 0.63-0.99; > 75 years relative risk at one year 0.93, 95% CI: 0.56-1.53; interaction P = 0.10).

CONCLUSIONS

Only two RCT have been published emphasizing the difficulty of enrolling critically ill patients. Despite large differences in shock severity, ERV benefit is similar across all ages and not significantly different for the elderly.

Percutaneous coronary intervention or coronary artery bypass surgery for cardiogenic shock and multivessel coronary artery disease?

BACKGROUND

Despite advances in treatment of cardiogenic shock (CS), the incidence of this serious complication of acute ST-elevation myocardial infarction (STEMI) has stayed relatively constant, and rates of mortality, although somewhat improved in recent decades, remain dauntingly high. Although both percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) are used in patients with CS with multivessel coronary disease, the optimal revascularization strategy in this setting remains unknown.

METHODS

We conducted a literature search and review of English language publications on CS in multiple online medical databases. Studies were included if they were (1) randomized controlled trials or observational cohort studies, (2) single-center or multicenter reports, (3) prospective or retrospective studies, and (4) contained information on PCI and CABG. Non-English language studies were excluded.

RESULTS

Our search retrieved no published findings from randomized clinical trials, and only 4 observational reports evaluating PCI versus CABG. Our review of the limited available data suggests similar mortality rates with CABG and PCI in patients with STEMI and multivessel coronary disease complicated by CS.

CONCLUSIONS

Limited data from observational studies in patients with CS and multivessel disease suggest that CABG should be considered a complementary reperfusion strategy to PCI and may be preferred, especially when complete revascularization with PCI is not possible. Our data highlight the need for large randomized trials to further evaluate the relative benefit of PCI versus CABG in patients with multivessel coronary disease and CS using contemporary surgical and percutaneous techniques.

Improved survival after acute myocardial infarction in patients with advanced Killip class

BACKGROUND

The continuing applicability of the Killip classification system to the effective stratification of long-term and short-term outcome in patients with acute myocardial infarction (MI) and its influence on treatment strategy calls for reanalysis in the setting of today's primary reperfusion treatments.

HYPOTHESIS

Our study sought to test the hypothesis that Killip classification, established on admission in patients with acute MI, is an effective tool for early prediction of in-hospital mortality and long-term survival.

METHODS

A series of 909 consecutive Olmsted County patients admitted with acute MI to St. Marys Hospital, Mayo Clinic, between January 1988 and March 1998 was analyzed. Killip classification was the primary variable. Endpoints were in-hospital death, major in-hospital complications, and post-hospital death.

RESULTS

Patients analyzed included 714 classified as Killip I, 170 classified as Killip II/III, and 25 classified as Killip IV. Increases in in-hospital mortality and prevalence of in-hospital complications correspond significantly with advanced Killip class (p < 0.01), with in-hospital mortality 7% in class I, 17.6% in classes II/III, and 36% in class IV patients (p < 0.001). Killip classification was strongly associated with mode of therapy administered within 24 h of admission (p < 0.01). Killip IV patients underwent primary angioplasty most commonly and were less likely to receive medical therapy.

CONCLUSIONS

Killip classification remains a strong independent predictor of in-hospital mortality and complications, and of long-term survival. Early primary angioplasty has contributed to a decrease in mortality in Killip IV patients, but effective adjunctive medical therapy is underutilized.

Emergent angioplasty prevents left ventricular dilation in patients with acute anterior wall myocardial infarction and cardiogenic shock

BACKGROUND

Percutaneous transluminal coronary angioplasty (PTCA) reduces in-hospital mortality and improves long-term outcome in patients with acute myocardial infarction (MI) complicated by cardiogenic shock. However, no study has evaluated the effects of different reperfusion therapies on left ventricular (LV) dimension and cardiac function in long-term survivors of MI with cardiogenic shock.

HYPOTHESIS

We investigated the effects of PTCA on the development of LV dilation in patients who survived MI complicated by cardiogenic shock.

METHODS

We studied 34 patients with a first MI and cardiogenic shock in whom two-dimensional echocardiography was performed immediately after admission and 1 month after infarction. Group A consisted of 17 patients who underwent emergent PTCA during the acute phase of MI, and Group B consisted of 17 patients who did not undergo PTCA. We also studied 119 patients with a first uncomplicated acute anterior MI, including 53 who underwent PTCA (Group C) and 66 who did not (Group D). The length and wall thickness of the infarcted and noninfarcted endocardial segments were determined immediately after MI and 1 month later, and LV ejection fraction (LVEF) was measured during the chronic phase.

RESULTS

The lengths of the infarcted and noninfarcted endocardial segments were significantly greater in Group B than in the other three groups (p < 0.05). The LVEF was significantly lower in Group B than in the other three groups (p < 0.05).

CONCLUSIONS

We conclude that PTCA performed in patients during the acute phase of MI complicated by cardiogenic shock lowers in-hospital mortality and prevents both LV dilation and a decrease in LVEF.

Cardiogenic shock: therapy and prevention

Cardiogenic shock is defined as profound circulatory failure resulting in insufficient tissue perfusion to meet resting metabolic demands. It occurs in approximately 7.5% of patients with acute myocardial infarction. Treatment strategies include inotropic agents, use of intra-aortic balloon counterpulsation, and revascularization. Current evidence supports the use of primary angioplasty. Surgery should be considered in patients with triple-vessel disease. If early catheterization is not available, thrombolytic therapy should be given to eligible patients and transfer to an interventional facility should be considered. Effective therapy for shock must also include a prevention strategy. This requires identification of patients at high risk for shock development and selection of patients who are candidates for aggressive intervention.

Cardiogenic shock: treatment

The treatment of cardiogenic shock complicating the acute coronary syndromes consists of medical therapy, percutaneous revascularization procedures, cardiac surgery, and the implantation of devices. Medical therapy is limited to different positive inotropic and vasoactive drugs, without any firm evidence of survival benefit using these drugs. Several new pharmacologic compounds are at different stages of clinical research, but are not yet routinely approved for the treatment of cardiogenic shock. The only evidence-based therapy with proven survival benefit is timely revascularization. Intra-aortic balloon pump counterpulsation maintains its central role as supportive treatment in cardiogenic shock patients. Anecdotal evidence is available about the use of ventricular assist devices, cardiac resynchronization therapy, and emergent heart transplantation.

Update on acute coronary syndromes and ST-elevation myocardial infarction

PURPOSE

The goal of modern therapy of acute myocardial infarction is twofold: to achieve rapid reperfusion of ischemic myocardium and to decrease subsequent remodeling, which can have deleterious effects on ventricular function and prognosis. The current paradigm for treatment of most patients with acute coronary syndromes is the consideration of an 'early invasive' strategy.

RECENT FINDINGS

Studies published this year have reinforced the importance of early reperfusion, solidified the evidence for early institution of aggressive adjunctive treatment, and added newer therapies to the existing armamentarium. This review evaluates published data from the past year encompassing advancements in percutaneous coronary intervention, drug-eluting stents, glycoprotein IIb/IIIa antagonists, thienopyridines, HMG-CoA reductase inhibitors, aldosterone blockade, low-molecular-weight heparins, direct thrombin inhibitors, implantable cardioverter-defibrillators, and beta-blockade in the treatment of acute coronary syndrome and ST-segment elevation myocardial infarction. In addition to patency of the epicardial coronary arteries, the role of the microvascular has become an area of recent interest.

SUMMARY

As novel modalities and approaches are put to the test of clinical trials, evidence-based therapies may help to lessen the adverse effects of myocardial ischemia and reduce future cardiovascular events.

Emergency revascularization in patients with cardiogenic shock on admission: a report from the SHOCK trial and registry

AIMS

To determine clinical correlates and optimal treatment strategy in patients with cardiogenic shock (CS) on admission.

METHODS AND RESULTS

In SHould we emergently revascularize Occluded Coronaries in cardiogenic shocK? (SHOCK) trial and registry patients with left ventricular (LV) dysfunction (n=1053), CS on admission occurred in 26% of directly admitted patients (n=166/627). Time from myocardial infarction to CS was shorter, initial haemodynamic profile poorer, and aggressive treatment less frequent in CS on admission than in delayed CS patients. CS on admission patients constituted a smaller relative proportion (11%) of the transferred (n=48/426) when compared with the directly admitted cohort (P<0.001). In-hospital mortality was higher (75 vs. 56%; P<0.001) with more rapid death (24-h mortality 40 vs. 17%; P<0.001) in CS on admission than in delayed CS patients. Emergency revascularization reduced in-hospital mortality in CS on admission (60 vs. 82%; P=0.001) and in delayed CS patients similarly (46 vs. 62%; P<0.001; interaction P=0.25). After adjustment for clinical differences, CS on admission was an independent predictor of in-hospital mortality (P=0.008).

CONCLUSION

CS on admission patients have a worse outcome but benefit equally from emergency revascularization as delayed CS patients, emphasizing the need for rapid and direct access of CS on admission patients to facilities providing this care.

Therapeutic strategies for cardiogenic shock, 2006

Cardiogenic shock, a devastating consequence of acute myocardial infarction, is associated with extremely high mortality. Treatment strategies should focus on prompt reperfusion and hemodynamic support. The primary approach for therapy is emergent angiography and revascularization using percutaneous coronary intervention or coronary artery bypass surgery, with the assistance of intra-aortic balloon pump counterpulsation. Several adjunctive pharmacologic agents, particularly inotropic drugs and vasopressors, are also helpful for hemodynamic support. However, these agents have not been shown to provide a survival benefit, and their use is primarily based on clinical experience. Since our last publication, several important advances have been made in the understanding and treatment of cardiogenic shock. Recent evidence suggests that a systemic inflammatory response, including the upregulation of inducible nitric oxide synthase, complement activation, and an inflammatory cytokine cascade, play a role in the development of cardiogenic shock. Newer therapeutic strategies, including C5 inhibitors and nitric oxide synthase inhibitors, are being combined with traditional strategies, such as inotropic agents, vasopressors, and circulatory assist, to treat cardiogenic shock.

Left ventricular assist device implantation after acute anterior wall myocardial infarction and cardiogenic shock: A two-center study

OBJECTIVE

Left ventricular assist device (LVAD) insertion after anterior wall myocardial infarction complicated by cardiogenic shock is an accepted modality of support in select patients. Results of primary revascularization for these patients are poor. We seek to determine the outcomes of patients with myocardial infarction and shock who undergo LVAD insertion alone versus surgical revascularization before LVAD insertion.

METHODS

Seventy-four patients at 2 institutions underwent LVAD implantation for myocardial infarction and shock over a 12-year period. Twenty-eight underwent direct LVAD placement, and 46 underwent revascularization through coronary artery bypass grafting before LVAD placement. Variables examined included patient demographics, myocardial infarction-LVAD interval, bridge to transplantation, early mortality (< or = 30 days), survival after LVAD placement, and posttransplantation survivals.

RESULTS

There were no differences in demographics between the 2 groups. The group undergoing revascularization before LVAD placement had a lower bridge to transplantation, higher early mortality, and lower overall 6- and 12-month survivals after LVAD placement compared with the group undergoing direct LVAD placement (45.50% vs 70.40%, P = .041; 39.10% vs 14.30%, P = .020; 89.3% and 82.1% vs 54.4% and 52.2%, respectively, P = .006). Posttransplantation survival and LVAD explantation rates were equivalent in both groups.

CONCLUSIONS

Coronary artery bypass grafting before LVAD insertion for cardiogenic shock complicating myocardial infarction adversely affects survival. Confirmation of these findings would require conducting a large, multicenter, randomized clinical trial comparing revascularization versus LVAD support as primary therapy in this setting.

Mortality after emergent percutaneous coronary intervention in cardiogenic shock secondary to acute myocardial infarction and usefulness of a mortality prediction model

Although percutaneous coronary intervention (PCI) in the setting of cardiogenic shock has a high in-hospital mortality rate, it has been shown to decrease the mortality rate in certain subgroups. The identity and relative importance of variables that are predictive of in-hospital mortality rate after PCI for cardiogenic shock are uncertain. Accordingly, we examined data of >300,000 patients in the American College of Cardiology-National Cardiovascular Data Registry (ACC-NCDR) that were collected from 1998 to 2002 and evaluated the outcomes in 483 consecutive patients who underwent emergency PCI for cardiogenic shock. Patients' mean age was 65 +/- 13 years, with men predominating (61%). All underwent emergency/salvage PCI in the setting of cardiogenic shock after acute myocardial infarction. Mean left ventricular ejection fraction was 30 +/- 16%. Stents were placed in 64% of patients, and thrombolytic agents were administered in 26%. Although PCI was angiographically successful in 79% of patients, the in-hospital mortality rate was 59.4%. Length of stay after PCI was 7.2 +/- 8 days. Logistic regression using all available variables identified 6 multivariate predictors of death: age (odds ratio [OR] 2.34, 95% confidence interval [CI] 1.68 to 3.28, p <0.001) for each 10-year increment, female gender (OR 1.55, 95% CI 1.00 to 2.41, p <0.001), baseline renal insufficiency (creatinine >2.0 mg/dl; OR 4.69, 95% CI 1.96 to 11.23, p <0.001), total occlusion in the left anterior descending artery (OR 1.99, 95% confidence interval 1.28 to 3.09, p <0.01), no stent used (OR 2.55, 95% CI 1.63 to 3.96, p <0.01), and no glycoprotein IIb/IIIa inhibitor used during PCI (OR 1.96, 95% CI 1.30 to 2.98, p <0.01). In a second analysis using only variables known to the clinician at the time of initial presentation, gender, age, renal insufficiency, and total occlusion of the left anterior descending coronary artery were significant. In conclusion, analysis of patients from the ACC-NCDR who underwent emergency PCI for acute myocardial infarction in the presence of cardiogenic shock shows an in-hospital mortality rate of approximately 60% when PCI is attempted.

Heart failure and shock complicating acute coronary syndromes

Heart failure (HF) complicating acute coronary syndromes (ACS) is a heterogeneous clinical syndrome characterized by varying degrees of pulmonary congestion, and in its severest form, by profound organ hypoperfusion (cardiogenic shock). The occurrence of HF in patients with ACS has long been recognized as a strong predictor of increased morbidity and mortality. As such, there is increased interest in better understanding the epidemiology and management of this common clinical syndrome. This manuscript reviews recent insights from work in this area, including recent important trials evaluating the impact of renin-angiotensin system inhibition, early beta-blockade, and aggressive reperfusion strategies.

Predictors of outcome after percutaneous treatment for cardiogenic shock

OBJECTIVES

To determine predictors of outcome after percutaneous coronary intervention (PCI) in patients with cardiogenic shock complicating acute myocardial infarction.

METHODS

Retrospective analysis of a cohort of 113 patients undergoing emergency coronary angiography and attempted PCI for cardiogenic shock complicating acute myocardial infarction in a regional cardiothoracic unit.

RESULTS

In-hospital mortality was 51% (58 patients). Adverse outcome was associated with previous myocardial infarction, age over 70 years, cardiogenic shock complicating failure to respond to thrombolytic treatment (failed thrombolysis), and multivessel coronary artery disease. Multivariate logistic regression analysis showed that the first three factors were independent predictors of in-hospital death with odds ratios of 5.21 (95% confidence interval (CI) 1.85 to 14.69), 4.02 (95% CI 1.14 to 14.12), and 3.78 (95% CI 1.43 to 9.96), respectively.

CONCLUSION

About 50% of patients with cardiogenic shock undergoing a strategy of urgent coronary angiography and PCI survive to hospital discharge. Survivors do well in the subsequent six months. Emergency PCI for cardiogenic shock reduces mortality from an expected 80% to about 50%. Clinical features can help determine which patients are most likely to gain from urgent coronary angiography and attempted PCI. Alternative strategies are needed to improve the outcome of patients who fare badly.

Impact of stents and abciximab on survival from cardiogenic shock treated with percutaneous coronary intervention

This retrospective observational review compares patient characteristics and in-hospital and long-term outcomes of cohorts of patients undergoing percutaneous coronary intervention (PCI) for cardiogenic shock complicating acute myocardial infarction (MI) prior to the use of stents (as well as glycoprotein IIb/IIIa inhibitor and dual-antiplatelet therapy) with PCI in the stent era. Cardiogenic shock remains the leading cause of hospital mortality from acute MI. This is a report of consecutive patients with cardiogenic shock complicating acute MI, without mechanical complication, referred for emergency catheterization to a single operator at two consecutive Veterans Affairs medical centers over a 15-year period (1988 to August 2003). PCI was attempted in all 93 cases: 44 consecutive patients in the present era and 49 consecutive patients in the stent era. Patients with comparable extent of coronary disease, more ST elevation myocardial infarction, multiple areas of infarction, and greater comorbidity underwent PCI in the stent era. Nevertheless, PCI in the stent era was associated with higher rates of acute success and improved in-hospital survival. Kaplan-Meier curves and log-rank testing showed highly significant improvement in overall survival (P < 0.0001). Logistic regression of in-hospital survival demonstrated that stent use (colinear with glycoprotein IIb/IIIa use and dual-antiplatelet therapy) was significantly associated with survival in a model adjusting for extent of coronary disease and comorbidities (P = 0.007). Stents and abciximab have been associated with improved acute angiographic and procedural success of PCI for cardiogenic shock, leading to improved survival.

Therapeutic Strategies for Cardiogenic Shock

Cardiogenic shock is a devastating consequence of acute myocardial infarction; it is associated with an extremely high mortality. Treatment strategies should be focused on prompt reperfusion, as well as hemodynamic support. The optimal approach for therapy is emergent angiography and revascularization using percutaneous coronary intervention or coronary artery bypass surgery, with the assistance of intra-aortic balloon pump counterpulsation. Several adjunctive pharmacologic agents, particularly inotropic drugs and vasopressors, are also helpful for hemodynamic support. However, these agents have not been shown to provide a survival benefit, and their use is primarily based on clinical experience.

Survival of patients treated with intra-aortic balloon counterpulsation for cardiogenic shock in a tertiary centre: variables correlated with death

OBJECTIVE

To describe the characteristics and mortality rates of 132 cardiogenic shock patients treated with intra-aortic balloon counterpulsation at a university hospital.

INTERVENTIONS

All patients underwent intra-aortic balloon counterpulsation. A total of 99 out of 132 patients were revascularized with angioplasty, surgery or were transplanted (intervention group), 33 out of 132 had no further intervention (no-intervention group).

MEASUREMENTS AND RESULTS

Overall mortality was 54.5% (72/132). In the intervention group mortality was 50.5% (50/99), in the no-intervention group mortality was 66.6% (22/33). The odds ratio for death comparing the intervention group with the no-intervention group was 0.533 (95% confidence interval 0.238-1.189, P = 0.122). By univariate analysis, diabetes and a left ventricular ejection fraction of less than 0.35 represented an increased odds ratio of death of 4.25 (1.813-9.965, P = 0.001) and 3.03 (1.22-7.54, P = 0.015), respectively. A lactate level greater than 2.5 mg/dl at baseline resulted in an increased odds ratio of death of 5.185 (1.988-13.525, P = 0.0001). Using a multivariate logistic regression analysis, a left ventricular ejection fraction less than 0.35 and diabetes remained significantly correlated with death.

CONCLUSION

Mortality rates remain high in cardiogenic shock patients in need of intra-aortic balloon counterpulsation. The odds ratio for death tended to be lower in the intervention group compared with the no-intervention group, although the absolute difference in mortality as a result of an intervention was only 15.2%, and did not reach statistical significance probably because of the small sample size. Diabetes and an ejection fraction lower than 35% are significant predictors for a worse prognosis.

Acute myocardial infarction complicated by early onset of heart failure: safety and feasibility of interhospital transfer for coronary angioplasty. Subanalysis of Killip II-IV patients from the PRAGUE-1 study

OBJECTIVE

The objective of this study is to assess the feasibility and safety of interhospital transfer (within up to 60 minutes) for primary/rescue coronary angioplasty of patients with myocardial infarction (AMI) complicated by an early onset of acute heart failure (AHF) admitted to a community hospital without PCI facilities.

DESIGN AND PATIENTS

From the multicenter randomized PRAGUE-1 study, a subgroup of 66 patients with AMI complicated by AHF on the first presentation to the community hospital were retrospectively analyzed. Group A patients (n = 21) were treated on site in community hospitals using thrombolysis (streptokinase), group B patients (n = 20) were transported with thrombolytic infusion to a PCI center for coronary angioplasty, and group C patients (n = 25) were immediately transported to a PCI center for primary angioplasty without thrombolysis.

RESULTS

No patient died during transportation. One group B patient developed ventricular fibrillation during transfer. The time delay from the onset of chest pain to reperfusion was > 142 minutes, and 253 and 251 minutes in groups A, B, and C, respectively. Hospital stay (16 vs 11 vs 10 days, P = NS) was shorter in the angioplasty groups. Transported patients (groups B, C) displayed a significant decrease in heart failure progression within the first 24 hours after treatment (48% vs 15% vs 8%, P < 0.05). The combined end point, i.e., mortality + nonfatal reinfarction (43% vs 25% vs 8%, P < 0.05), was significantly less frequent in the coronary angioplasty group.

CONCLUSIONS

Interhospital transfer for coronary angioplasty of patients with AMI complicated by an early onset of AHF is feasible and safe. Transport for angioplasty may even reduce the risk of heart failure progression and improve clinical outcome compared to immediate thrombolysis in the nearest community hospital.

AngioJet thrombectomy and stenting for reperfusion in acute MI complicated with cardiogenic shock

AngioJet thrombectomy (AJ) has been shown to be safe and effective in treatment of acute myocardial infarction (AMI). However, use of AJ has not been studied extensively in AMI with cardiogenic shock (CS). Clinical outcomes in 19 patients with CS and treated with AJ were retrospectively analyzed. Immediate stenting was also performed. Procedure success (final diameter stenosis < 50% and TIMI flow > or = 2) was achieved in 95%, with final TIMI 3 flow in 89%. Clinical success (procedure success without major in-hospital cardiac events) was achieved in 68%. There were five in-hospital deaths and no patients experienced stroke or required emergent bypass surgery. At 30-day follow-up, there were no additional deaths or stroke, and two patients had undergone target vessel revascularization. AJ is relatively safe and effective in the setting of AMI complicated with CS, allowing for immediate definitive treatment. This strategy may offer improved mortality in these high-risk patients.

Outcomes research in the development and evaluation of practice guidelines

BACKGROUND

Practice guidelines have been developed in response to the observation that variations exist in clinical medicine that are not related to variations in the clinical presentation and severity of the disease. Despite their widespread use, however, practice guideline evaluation lacks a rigorous scientific methodology to support its development and application.

DISCUSSION

Firstly, we review the major epidemiological foundations of practice guideline development. Secondly, we propose a chronic disease epidemiological model in which practice patterns are viewed as the exposure and outcomes of interest such as quality or cost are viewed as the disease. Sources of selection, information, confounding and temporal trend bias are identified and discussed.

SUMMARY

The proposed methodological framework for outcomes research to evaluate practice guidelines reflects the selection, information and confounding biases inherent in its observational nature which must be accounted for in both the design and the analysis phases of any outcomes research study.

Long-term results after acute percutaneous transluminal coronary angioplasty in acute myocardial infarction and cardiogenic shock

The aim of this study was to determine the long-term outcome in unselected, consecutive patients after acute percutaneous transluminal angioplasty (PTCA) for acute myocardial infarction (AMI) complicated by cardiogenic shock. This involved a follow-up study from a prospectively conducted patient registry in a tertiary referral center. A total of 59 patients (10 female/49 male; median age 62 years (32-91)) with percutaneous transluminal cardiac interventions in primary cardiogenic shock were identified between January 1995 and January 2000. Twenty-two patients (37%) had been resuscitated successfully before intervention. The in-hospital mortality of shock patients was 36% (n=21, median age 68 (47-84)). The median follow-up of survivors was 18.1 (7-57.3) months, during which three further patients died (8%; two because of sudden cardiac deaths, one because of acute reinfarction). Achievement of thrombolysis in myocardial infarction (TIMI) flow III after acute PTCA (84% in survivors vs. 38% in non-survivors; P<0.001) and the absence of the left main coronary artery (3% survivors vs. 29% non-survivors; P=0.003) as culprit lesion in patients with cardiogenic shock was strongly associated with an improved survival rate. A second cardiac intervention was performed in seven patients (18%). Overall functional capacity of shock survivors was good. At final follow-up, 80% of the survivors were completely asymptomatic. One patient had angina pectoris NYHA II, five patients dyspnoea NYHA class II. Exercise stress-test was performed in 24 of the 38 surviving patients, median exercise capacity was 100% (range 55-113%) of the age adjusted predicted value. In unselected patients with cardiogenic shock due to AMI, treatment with acute PTCA resulted in an in-hospital mortality of 36%, low late mortality and good functional capacity in long-term survivors. TIMI flow grade III after acute PTCA in patients with acute myocardial infarction complicated by cardiogenic shock was strongly associated with an improved survival rate whereas the left main coronary artery as culprit lesion was associated with worse outcome.