Shock after acute myocardial infarction. A clinical and hemodynamic profile

Neural correlates of inhibitory control are associated with stimulant-like effects of alcohol

Poor inhibitory control and heightened feelings of stimulation after alcohol are two well-established risk factors for alcohol use disorder (AUD). Although these risk factors have traditionally been viewed as orthogonal, recent evidence suggests that the two are related and may share common neurobiological mechanisms. Here we examined the degree to which neural activity during inhibition was associated with subjective reports of stimulation following alcohol. To assess neural changes during inhibition, moderate alcohol drinkers performed a stop signal task during fMRI without drug. To assess subjective responses to alcohol they ingested alcohol (0.8 g/kg) or placebo beverages under double-blind conditions and provided subjective reports of stimulation and sedation. Feelings of stimulation following alcohol were inversely associated with activity in the supplementary motor area, insula, and middle frontal gyrus during inhibition (successful stop trials compared to go trials). Feelings of sedation did not correlate with brain activation. These results extend previous findings suggesting that poor inhibitory control is associated with more positive subjective responses to alcohol. These interrelated risk factors may contribute to susceptibility to future excessive alcohol use, and ultimately lead to neurobiological targets to prevent or treat AUD.

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.

Cardiogenic shock: a historical perspective

Significant progress has been made over the past 60 years in defining and recognizing cardiogenic shock (CS), and there have been tremendous advances in the care of patients who have this illness. Although there are many causes of this condition, acute myocardial infarction with loss of a large amount of functioning myocardium is the most frequent cause. It was recognized early in the study of CS that prompt diagnosis and rapid initiation of therapy could improve the prognosis, and this remains true today. Although the mortality from CS remains high, especially in elderly populations, modern therapies improve the chance of survival from this critical illness.

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.

Critical care aspects in the management of patients with acute coronary syndromes

The spectrum of acute coronary syndromes (ACS) includes several clinical complexes that frequently cause critical instability in affected patients. This article focuses on several critical care aspects of these unstable ACS patients. The management of cardiogenic shock can be particularly challenging because the mechanical defects are varied in cause, severity, and specific treatment. Complications of fibrinolytic therapy are potentially deadly and arrhythmias are relatively common in the ACS patients. Discussions on the management of these problems should help the emergency physician more effectively to treat critically ill patients with ACS.

Recent magnitude of and temporal trends (1994-1997) in the incidence and hospital death rates of cardiogenic shock complicating acute myocardial infarction: the second national registry of myocardial infarction

BACKGROUND

Limited recent data are available to describe the magnitude of, and temporal trends in, the incidence and case-fatality rates associated with cardiogenic shock complicating acute myocardial infarction. The purpose of this study was to examine recent (1994-1997) trends in the incidence of, and hospital death rates from, cardiogenic shock complicating acute myocardial infarction from a large, multihospital national perspective.

METHODS

An observational study was performed of 426,253 patients hospitalized with acute myocardial infarction in 1662 hospitals throughout the United States between 1994 and 1997.

RESULTS

The incidence rates of cardiogenic shock averaged 6.2%. There was evidence for a slight decline in these rates between 1994 (6.6%) and 1997 (6.0%). Results of a multivariable regression analysis controlling for factors that might affect the risk of development of cardiogenic shock indicated that patients hospitalized in more recent years were at significantly lower risk for shock. Patients with shock had a markedly increased risk for dying during hospitalization compared with patients not having shock (74% vs 10%). Significant, albeit small, absolute differences were observed in the risk of dying after cardiogenic shock over time (76% dying in 1997, 72% dying in 1994). These improving trends were magnified, however, after potentially confounding prognostic factors were controlled: patients having shock in 1997 were at approximately one fifth lower risk of dying (odds ratio 0.79, 95% confidence interval 0.71-0.87) than those hospitalized in 1994.

CONCLUSIONS

Our findings indicate a slight decline in the incidence rates of cardiogenic shock and improving trends in the hospital survival of patients with shock. Despite these trends, it remains of considerable importance to prevent this clinical syndrome, given its high lethality.

Angiographic findings and clinical correlates in patients with cardiogenic shock complicating acute myocardial infarction: a report from the SHOCK Trial Registry. SHould we emergently revascularize Occluded Coronaries for cardiogenic shocK?

OBJECTIVES

We sought to delineate the angiographic findings, clinical correlates and in-hospital outcomes in patients with cardiogenic shock (CS) complicating acute myocardial infarction.

BACKGROUND

Patients with CS complicating acute myocardial infarction carry a grave prognosis. Detailed angiographic findings in a large, prospectively identified cohort of patients with CS are currently lacking.

METHODS

We compared the clinical characteristics, angiographic findings, and in-hospital outcomes of 717 patients selected to undergo angiography and 442 not selected, overall and by shock etiology: left or right ventricular failure versus mechanical complications.

RESULTS

Patients who underwent angiography had lower baseline risk and a better hemodynamic profile than those who did not. Overall, 15.5% of the patients had significant left main lesions on angiography, and 53.4% had three-vessel disease, with higher rates of both for those with ventricular failure, compared with patients who had mechanical complications. Among patients who underwent angiography, those with ventricular failure had significantly lower in-hospital mortality than patients with mechanical complications (45.2% vs. 57.0%; p = 0.021). Importantly, for patients with ventricular failure, in-hospital mortality also correlated with disease severity: 35.0% for no or single-vessel disease versus 50.8% for three-vessel disease. Furthermore, mortality was associated with the culprit lesion location (78.6% in left main lesion, 69.7% in saphenous vein graft lesions, 42.4% in circumflex lesions, 42.3% in left anterior descending lesions, and 37.4% in right coronary artery lesions), and Thrombolysis In Myocardial Infarction (TIMI) flow grade (46.5% in TIMI 0/1, 49.4% in TIMI 2 and 26% in TIMI 3).

CONCLUSIONS

Patients who underwent angiographic study in the SHOCK Trial Registry had a more benign cardiac risk profile, more favorable hemodynamic findings and lower in-hospital mortality than those for whom angiograms were not obtained. Patients with CS caused by ventricular failure had more severe atherosclerosis, and a different distribution of culprit vessel involvement but lower in-hospital mortality, than those with mechanical complications. Overall in-hospital survival correlates with the extent of coronary artery obstructions, location of culprit lesion and baseline coronary TIMI flow grade.

[The practical clinical guidelines of the Sociedad Española de Cardiología on coronary surgery]

Surgery in coronary disease, including myocardial revascularization and the surgery of mechanical complications of acute myocardial infarction, has shown to improve the symptoms, quality of life and/or prognosis in certain groups of patients. The expected benefit in each patient depend on many well-known factors among which the appropriateness of the indication for surgery is fundamental. The objective of these guidelines is to review current indications for cardiac surgery in patients with coronary heart disease through an evaluation of the degree of evidence of effectiveness in the light of current knowledge (systematic review of bibliography) and expert opinion gathered from various reports. Indications and the degree of recommendation for conventional coronary artery bypass grafting have been established for each of the most frequent anatomo-clinical situations defined by clinical symptoms (stable angina, unstable angina and acute myocardial infarction) as well as by left ventricular function and extend of coronary disease. Furthermore, the subgroups with the greatest surgical risk and stratification models are described to aid the decision making process. Also we analyse the rational basis and indication for the new surgical techniques such as minimally invasive coronary surgery and total arterial revascularization. Finally, the indication and timing of surgery in patients with mechanical complications of acute myocardial infarction are considered.

Predictors of cardiogenic shock after thrombolytic therapy for acute myocardial infarction

OBJECTIVES

This study characterized clinical factors predictive of cardiogenic shock developing after thrombolytic therapy for acute myocardial infarction (AMI).

BACKGROUND

Cardiogenic shock remains a common and ominous complication of AMI. By identifying patients at risk of developing shock, preventive measures may be implemented to avert its development.

METHODS

We analyzed baseline variables associated with the development of shock after thrombolytic therapy in the Global Utilization of Streptikonase and Tissue-Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I) trial. Using a Cox proportional hazards model, we devised a scoring system predicting the risk of shock. This model was then validated in the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO-III) cohort.

RESULTS

Shock developed in 1,889 patients a median of 11.6 h after enrollment. The major factors associated with increased adjusted risk of shock were age (chi2 = 285, hazard ratio [95% confidence interval] 1.47 [1.40, 1.53]), systolic blood pressure (chi2 = 280), heart rate (chi2 = 225) and Killip class (chi2 = 161, hazard ratio 1.70 [1.52, 1.90] and 2.95 [2.39, 3.63] for Killip II versus I and Killip III versus I, respectively) upon presentation. Together, these four variables accounted for >85% of the predictive information. These findings were transformed into an algorithm with a validated concordance index of 0.758. Applied to the GUSTO-III cohort, the four variables accounted for > 95% of the predictive information, and the validated concordance index was 0.796.

CONCLUSIONS

A scoring system accurately predicts the risk of shock after thrombolytic therapy for AMI based primarily on the patient's age and physical examination on presentation.

Cardiogenic shock in patients with acute ischemic syndromes with and without ST-segment elevation

BACKGROUND

Cardiogenic shock is usually considered a sequela of ST-segment elevation myocardial infarction. There are limited prospective data on the incidence and significance of shock in non-ST-segment elevation patients. This study assessed the incidence and outcomes of cardiogenic shock developing after enrollment among patients with and without ST-segment elevation in the Global Use of Strategies To Open Occluded Coronary Arteries (GUSTO)-IIb trial.

METHODS AND RESULTS

Among 12,084 patients in GUSTO-IIb who did not present with cardiogenic shock, 4092 (34%) had and 7991 (66%) did not have ST-segment elevation on the enrollment ECG. Cardiogenic shock developed in 4.2% of ST-segment elevation patients compared with 2.5% of patients without ST-segment elevation (odds ratio, 0. 581; 95% CI, 0.472 to 0.715; P<0.001). Shock developed significantly later among patients without ST-segment elevation. There were significant differences in baseline characteristics between shock patients with and without ST-segment elevation: Patients without ST-segment elevation were older, more frequently had diabetes mellitus and 3-vessel disease, but had less TIMI grade 0 flow at angiography. Regardless of the initial ECG, mortality was high: 63% among patients with ST-segment elevation and 73% in those without ST-segment elevation.

CONCLUSIONS

Cardiogenic shock occurs in the setting of acute ischemic syndromes regardless of whether ST-segment elevation is present. The incidence, patient characteristics, timing, clinical course, and angiographic findings differ between the 2 groups. Mortality from cardiogenic shock is similarly high among patients with and without ST-segment elevation.

Acute myocardial infarction with cardiogenic shock on admission: incidence, prognostic implications, and current treatment strategies. Results from "the 60-Minutes Myocardial Infarction Project". ALKK ("Arbeitsgemeinschaft leitender Krankenhauskardiologen") Study Group

Little data exist about current treatment strategies the efficacy of thrombolytic therapy and outcome of patients with acute myocardial infarction (AMI) presenting in cardiogenic shock (CS). Data from the German multicenter "60 Minutes Myocardial Infarction Project" were used to analyze a large number of patients with AMI and CS on admission and to compare those to patients without CS. Between July 1993 and September 1994 a total of 7,085 patients with AMI were registered. Out of these, 179 patients (2.5%) presented in CS (systolic blood pressure < 100 and heart rate > 100/min, resuscitated patients were excluded). Patients in CS were significantly older than patients without CS. Their in-hospital mortality was 47.1% compared with 12.4% in patients without CS (p = 0.001). The prevalence of the following clinical parameters was significantly higher in patients with CS than in those without CS: bundle branch block, prior MI, and a non-diagnostic ECG (all p < 0.05). Thrombolytic therapy was used in 36.3% of patients in CS and in 50.8% of those without CS (p = 0.001). The in-hospital mortality in patients with CS receiving thrombolytic therapy was significantly lower than in patients with CS who did not receive thrombolytic agents (33.3% versus 55.1%; p = 0.006). In daily clinical practice in Germany thrombolytic treatment is used in only 36.3% of patients with AMI presenting in CS on admission. The use of thrombolysis in CS on admission is associated with a lower in-hospital mortality.

Reperfusion therapy in cardiogenic shock complicating acute myocardial infarction

The most frequent cause of cardiogenic shock complicating acute myocardial infarction is extensive myocardial damage involving a relevant amount of myocardium. Treatment is aimed at support for the circulation with the use of drugs and mechanical devices and at restoration of perfusion to the ischemic myocardium as soon as possible. Therefore, emergency coronary angiography is indicated in all patients. Coronary angioplasty is the first option in patients with suitable anatomy because it is the fastest available technique able to recanalize the infarct-related vessel. Stenting of the infarct artery must be considered because stent implantation has been shown to improve results in comparison with the balloon alone. Complete revascularization is likely to offer a better outcome in patients with multivessel disease. Coronary surgery is indicated as first-line intervention in patients who have a coronary anatomy not suitable for angioplasty; it may also serve to complete revascularization in patients with multivessel disease initially treated with emergency coronary angioplasty. In a hospital without facilities for emergency coronary interventions, mechanical circulatory support with an intra-aortic balloon pump should be instituted and thrombolysis started; then patients should be transferred immediately to a tertiary center to undergo coronary angiography and revascularization procedures, if needed. In patients not benefiting from this aggressive revascularization strategy who develop irreversible extensive myocardial damage, heart transplantation must be considered.

Cardiogenic shock complicating acute myocardial infarction: predictors of death. GUSTO Investigators. Global Utilization of Streptokinase and Tissue-Plasminogen Activator for Occluded Coronary Arteries

BACKGROUND

Current knowledge of predictors of death among patients with cardiogenic shock complicating myocardial infarction is limited. We aimed to develop a risk assessment prognostic algorithm of 30-day mortality, including clinical and hemodynamic data prospectively collected among patients with cardiogenic shock in the 41,021-patient Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I) trial.

METHODS

We used logistic regression modeling techniques to evaluate the relations between demographic, clinical, and hemodynamic characteristics and 30-day mortality rate for the entire shock population (n = 2968) and for patients who underwent right-heart catheterization (n = 995).

RESULTS

The odds (95% confidence interval) of dying were 1.49 times higher (1.27-1.74) for patients 10 years older and 1.70 times higher (1.19-2.44) for patients with prior infarction. Findings derived from physical examination, such as altered sensorium and cold, clammy skin, were important independent predictors of prognosis (odds of dying 1.68 times higher for each [1.19-2.39 and 1.15-2.46]). The odds of dying were also 2.25 times higher (1.61-3.15) in patients with oliguria. Mortality rate was lowest for cardiac output and pulmonary capillary wedge measurements of 5.1 L/min and 20 mm Hg, respectively, and increased with either higher or lower values. Patients with shock had better outcomes than patients in whom shock developed later, although for the latter subgroup, prognosis was worse in patients who had heart failure (Killip class II to III).

CONCLUSIONS

We devised a prognostic algorithm for patients with cardiogenic shock complicating acute myocardial infarction. In addition to demographic and easily derived physical examination features, data derived from right-heart catheterization added valuable information that increased the ability to predict outcome in this high-risk population.

Temporal trends in cardiogenic shock complicating acute myocardial infarction

BACKGROUND

Limited information is available on trends in the incidence of and mortality due to cardiogenic shock complicating acute myocardial infarction. We studied the incidence of cardiogenic shock complicating acute myocardial infarction and in-hospital death rates among patients with this condition in a single community from 1975 through 1997.

METHODS

We conducted an observational study of 9076 residents of metropolitan Worcester, Massachusetts, who were hospitalized with confirmed acute myocardial infarction in all local hospitals during 11 one-year periods between 1975 and 1997. Our study included periods before and after the advent of reperfusion therapy.

RESULTS

The incidence of cardiogenic shock remained relatively stable over time, averaging 7.1 percent among patients with acute myocardial infarction. The results of a multivariable regression analysis indicated that the patients hospitalized during recent study years were not at a substantially lower risk for shock than patients hospitalized in the mid-to-late 1970s. Patients in whom cardiogenic shock developed had a significantly greater risk of dying during hospitalization (71.7 percent) than those who did not have cardiogenic shock (12.0 percent, P<0.001). A significant trend toward an increase in in-hospital survival among patients with cardiogenic shock in the mid-to-late 1990s was found in crude and adjusted analyses.

CONCLUSIONS

Our findings indicate no significant change in the incidence of cardiogenic shock complicating acute myocardial infarction over a 23-year period. However, the short-term survival rate has increased in recent years at the same time as the use of coronary reperfusion strategies has increased.

Echocardiographic Assessment of Complications Related to Left Ventricular Function in Acute Myocardial Infarction

Three complications of acute myocardial infarction without myocardial rupture are directly associated to the function of the myocardium: papillary muscle dysfunction, congestive heart failure, and cardiogenic shock. In this article, the pathophysiological mechanism of each complication is discussed, and the contribution of echocardiography to diagnosis and management is reviewed.

Projected cost-effectiveness of primary angioplasty for acute myocardial infarction

OBJECTIVES

This study sought to evaluate the cost-effectiveness of primary angioplasty for acute myocardial infarction under varying assumptions about effectiveness, existing facilities and staffing and volume of services.

BACKGROUND

Primary angioplasty for acute myocardial infarction has reduced mortality in some studies, but its actual effectiveness may vary, and most U.S. hospitals do not have cardiac catheterization laboratories. Projections of cost-effectiveness in various settings are needed for decisions about adoption.

METHODS

We created a decision analytic model to compare three policies: primary angioplasty, intravenous thrombolysis and no intervention. Probabilities of health outcomes were taken from randomized trials (base case efficacy assumptions) and community-based studies (effectiveness assumptions). The base case analysis assumed that a hospital with an existing laboratory with night/weekend staffing coverage admitted 200 patients with a myocardial infarction annually. In alternative scenarios, a new laboratory was built, and its capacity for elective procedures was either 1) needed or 2) redundant with existing laboratories.

RESULTS

Under base case efficacy assumptions, primary angioplasty resulted in cost savings compared with thrombolysis and had a cost of $12,000/quality-adjusted life-year (QALY) saved compared with no intervention. In sensitivity analyses, when there was an existing cardiac catheterization laboratory at a hospital with > or = 200 patients with a myocardial infarction annually, primary angioplasty had a cost of < $30,000/QALY saved under a wide range of assumptions. However, the cost/QALY saved increased sharply under effectiveness assumptions when the hospital had < 150 patients with a myocardial infarction annually or when a redundant laboratory was built.

CONCLUSIONS

At hospitals with an existing cardiac catheterization laboratory, primary angioplasty for acute myocardial infarction would be cost-effective relative to other medical interventions under a wide range of assumptions. The procedure's relative cost-ineffectiveness at low volumes or redundant laboratories supports regionalization of cardiac services in urban areas. However, approaches to overcoming competitive barriers and close monitoring of outcomes and costs will be needed.

Primary angioplasty and thrombolysis for acute myocardial infarction: an evidence summary

Coronary angioplasty is being increasingly used as the primary treatment for patients with acute myocardial infarction, but controversy remains over its potential adoption in preference to thrombolysis as standard care. This report summarizes the published evidence on health outcomes after primary angioplasty compared with thrombolysis or no intervention for patients with acute myocardial infarction. The data tables presented provide the scientific groundwork to assist physicians and other policy-makers in deciding which interventions to provide for broad populations of patients.

Acute myocardial infarction and congestive heart failure

The effective treatment of patients with acute myocardial infarction (AMI) and acute congestive heart failure (CHF) requires quick triage, accurate identification, and appropriate pharmacologic management. This article describes the initial assessment and management of adult patients with AMI and CHF, beginning with the first interaction of such patients with the emergency department staff.

Cardiogenic shock: thrombolysis or angioplasty?

Cardiogenic shock (CGS) occurs in 3 to 20% of patients presenting with acute myocardial infarction (MI), and it generally involves dysfunction of at least 40% of the total myocardial mass. Prior to the advent of balloon angioplasty and thrombolysis, in-hospital mortality was greater than 75%. This mortality rate has been consistent in reported series despite the advent of cardiac intensive care units, vasopressor, inotropic, and vasodilator therapy. Intra-aortic balloon counterpulsation therapy provides hemodynamic improvement, and it may provide some mortality benefit when used in conjunction with appropriate revascularization. Survival studies have shown that patency of the infarct-related artery is a strong predictor of survival. No randomized trials have been completed to examine which reperfusion therapy best treats this emergent situation. Subgroup analysis of large scale, multicenter trials, although underpowered, has shown no improvement in mortality with use of thrombolytic agents, leading many to advise use of mechanical intervention. In patients who present with acute MI with contraindications to thrombolysis, primary angioplasty is the treatment of choice. At selected centers, primary angioplasty is comparable to or better than thrombolytic therapy for patients presenting with acute MI, with or without CGS. Studies examining angioplasty in patients with CGS have shown high procedural success rates (75%) and reduced in-hospital mortality (44%), particularly in those patients with successful revascularization. Emergency bypass surgery may improve survival, but it is costly, unavailable to many, and often leads to excessive delays in therapy. If available, we believe that primary angioplasty is the treatment of choice for patients with CGS.

Early and 1-year survival rates in acute myocardial infarction complicated by cardiogenic shock: a retrospective study comparing coronary angioplasty with medical treatment

Cardiogenic shock remains a frequently lethal complication of acute myocardial infarction. Early revascularization of the infarct-related artery by coronary angioplasty has been suggested to significantly improve patient survival. In-hospital and 1-year survival was assessed in 50 patients hospitalized for acute myocardial infarction complicated by cardiogenic shock. All patients received medical treatment and intraaortic balloon pump support. Thirty-three patients underwent coronary angioplasty (PTCA group), while 17 patients remained on conventional therapy (no PTCA group). The two groups were comparable for all baseline characteristics. Survival was significantly better in the PTCA group than in the no PTCA group: 64% versus 24% in-hospital survival (p = 0.007) and 52% versus 12% at 1 year (p = 0.006). When angioplasty was successful in achieving reperfusion, survival was further enhanced: in-hospital survival rate was 76% versus 25% in patients with unsuccessful angioplasty and 60% versus 25% at 1 year.

Contemporary reperfusion therapy for cardiogenic shock: the GUSTO-I trial experience. The GUSTO-I Investigators. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries

OBJECTIVES

This study sought to examine the incidence, temporal profile and clinical implications of shock in a large trial of thrombolytic therapy for acute myocardial infarction.

BACKGROUND

Despite advances in the treatment of acute ischemic syndromes, cardiogenic shock remains associated with significant morbidity and mortality.

METHODS

Patients who presented within 6 h of symptom onset were randomized to four treatment strategies: 1) streptokinase plus subcutaneous heparin; 2) streptokinase plus intravenous heparin; 3) accelerated recombinant tissue-type plasminogen activator (rt-PA) plus intravenous heparin; or 4) streptokinase and rt-PA plus intravenous heparin. The primary end point was 30-day all-cause mortality.

RESULTS

Shock occurred in 2,972 patients (7.2%): 315 (11%) had shock on arrival, and 2,657 (89%) developed shock after hospital admission. Reinfarction occurred in 11% of patients who developed shock compared with 3% of patients without shock. The mortality rate was significantly higher in patients who presented with (57%) or developed (55%) shock than in those without shock (3%) (p < 0.001). Shock developed significantly less frequently in patients receiving rt-PA. There were fewer deaths in patients who presented with shock and were treated with streptokinase plus intravenous heparin or who developed shock and were treated with streptokinase plus subcutaneous heparin. Patients who developed shock had a significantly lower 30-day mortality rate if angioplasty was performed.

CONCLUSIONS

Because cardiogenic shock occurred most often after admission and with recurrent ischemia and reinfarction, recognizing signs of incipient shock may improve outcome. Fewer patients treated with rt-PA developed shock, yet those developing shock had the same high mortality rate as those presenting with shock, regardless of treatment. Only angioplasty was associated with a significantly lower mortality rate.

Immediate and long-term survival after intra-aortic balloon pumping: is advanced age an independent, unfavorable prognostic factor?

OBJECTIVE

To determine whether advanced age is an independent prognostic factor that may increase the risk of complications and reduce the immediate and long-term survival after treatment with intra-aortic balloon pumping (IABP) for acute ischemic heart disease.

DESIGN

Retrospective analysis of a clinical series and long-term follow-up study.

PATIENTS

A total of 142 patients (age range 23-86 years) in whom IABP was indicated following a standardized protocol.

MEASUREMENTS

Univariate analysis of the association between age and anamnestic, clinical, and hemodynamic data significantly affecting prognosis; multivariate logistic regression analysis of variables showing significant associations.

RESULTS

IABP-related complications were independent of age. At univariate analysis, pre-existing, noncardiac, associated conditions (chronic renal failure, stroke, bronchopulmonary disease) (P < .001), an indication to IABP for hemodynamic complications of acute myocardial infarction rather than for medically refractory myocardial ischemia (P < .001), a lack in hemodynamic response to IABP (P < .002), a prolonged delay to IABP initiation (P < .003), and advanced age (P < .025) were all predictors of in-hospital mortality. However, older patients were also more frequently affected by chronic comorbid conditions and by acute left ventricular failure as an indication to IABP. When these variables were entered into logistic regression models, the association between age and mortality was no longer statistically significant. Similarly, advancing age was associated (P < .012) with an increased mortality rate during an average follow-up of 94 +/- 9 months, but, again, such a significant association disappeared when simultaneously adjusting for New York Heart Association functional class, which was the single most important predictor of long-term mortality.

CONCLUSIONS

Several anamnestic and clinical variables, rather than advanced age itself, are independent, prognostic factors negatively affecting the outcome of treatment with IABP. Technique-related complications are independent of age. Thus, old age should not be considered as a criterion to exclude any patient, a priori, from the potential benefits of this type of cardiocirculatory assistance.

Emergency cardiopulmonary bypass support in patients with cardiac arrest caused by myocardial infarction

Emergency percutaneous cardiopulmonary bypass support (PCPS) was instituted in 3 patients with acute myocardial infarction in cardiac arrest refractory to conventional resuscitation measures. All had severe double or triple vessel disease. Percutaneous transluminal coronary angioplasty (PTCA) was performed in 1 patient and PTCA and directional coronary atherectomy (DCA) were performed in the other 2 patients on combined intraaortic balloon pumping (IABP) and PCPS. Flow rates of 2 to 5 L/min were achieved, with restoration of mean arterial pressure to more than 60 mm Hg during PCPS. The status of all patients was improved hemodynamically with PCPS. One patient died of hemorrhage during PCPS. DCA was successfully performed in the other 2 patients, and PCPS and IABP was discontinued. Time on PCPS ranged from 10 h to 8 days. Time on IABP ranged from 10 days to 2 weeks. These 2 patients died of pneumonia or multiorgan failure after 1.5 months. In conclusion, emergency PCPS is a powerful resuscitative tool that may stabilize the condition of patients in cardiac arrest to allow for definitive intervention.

Treatment strategies for acute myocardial infarction complicated by cardiogenic shock in a community hospital

The risk and benefits of three treatment strategies were examined in 64 consecutive patients with acute myocardial infarction and cardiogenic shock. Thirteen patients received thrombolytic therapy (group 1), 29 patients received intra-aortic balloon pump counterpulsation support (group 2), and 22 patients were treated with combined thrombolytic therapy and intra-aortic balloon pump counterpulsation support (group 3). The groups were similar in regard to age, sex, medical history, hemodynamic data, and extent of coronary artery disease. Survival was improved in patients treated with combined thrombolytic therapy and intra-aortic balloon pump counterpulsation support (group 1, 23 percent; group 2, 28 percent; and group 3, 68 percent; p = 0.0049). Seven percent of the patients who remained at the community hospital survived vs 69 percent who were transferred to a tertiary care center (p < 0.001), and 17 percent survived who were treated medically vs 71 percent who received revascularization (p < 0.001). These findings suggest that patients who present to a community hospital in cardiogenic shock can have their conditions stabilized, and they can then be transferred to a tertiary care hospital for revascularization and have the same outcome as patients who initially present to tertiary care hospitals.

Cardiogenic shock complicating acute myocardial infarction in patients without heart failure on admission: incidence, risk factors, and outcome. SPRINT Study Group

PURPOSE

Patients with large myocardial infarction (MI) presenting with clinical signs of heart failure are at increased risk for subsequent development of cardiogenic shock and death. Little is known, however, about the development of cardiogenic shock among patients with acute MI presenting without clinical signs of heart failure. The aim of the present study was to examine the incidence, predictors for occurrence, and outcome of in-hospital development of cardiogenic shock among patients with acute MI without heart failure on admission.

PATIENTS AND METHODS

Clinical data of 5,839 consecutive patients hospitalized with acute MI were analyzed.

RESULTS

Of 3,465 (59%) patients without heart failure on admission (Killip class I), 89 (2.6%) developed cardiogenic shock during their hospital stay. This represented 24% of all cases of in-hospital cardiogenic shock in the entire group. Cardiogenic shock developed more than 24 hours after admission in 66% of cases. All but three patients with cardiogenic shock died whereas a 5% in-hospital mortality was found among patients without cardiogenic shock. Independent predictors for in-hospital shock were age (for a 10-year increment, adjusted relative odds [RO] = 2.45, 90% confidence interval [CI] = 1.50 to 4.02); female gender (RO = 1.51, 90% CI = 0.91 to 2.50); history of angina (RO = 2.64, 90% CI = 1.36 to 3.76); history of stroke (RO = 2.12, 90% CI = 1.26 to 6.35); peripheral vascular disease (RO = 1.99, 90% CI = 0.95 to 4.18); peak lactate dehydrogenase (LDH) greater than four times the normal (RO = 3.16, 90% CI = 1.79 to 5.57); and hyperglycemia on admission (RO = 3.52, 90% CI = 2.13 to 5.84). Patients with six risk factors (excluding LDH values) had an estimated probability of 35% for developing in-hospital cardiogenic shock.

CONCLUSIONS

(1) A significant proportion of MI patients who developed cardiogenic shock during hospitalization were free of heart failure on admission. (2) Our study identified several risk factors facilitating early identification of subgroups at risk for cardiogenic shock within otherwise low-risk patients.

Prognosis in cardiogenic shock after acute myocardial infarction in the interventional era

OBJECTIVES

The purpose of this study is to describe the outcome in cardiogenic shock treated with aggressive reperfusion therapy and to identify factors predictive of in-hospital and long-term mortality.

BACKGROUND

Cardiogenic shock is the most common cause of death in patients admitted to the coronary care unit. Although studies have reported lower mortality rates in shock treated with angioplasty, few studies have described a cohort of patients with shock who were not selected because they were most likely to benefit from reperfusion therapy.

METHODS

A consecutive series of 200 patients admitted with acute myocardial infarction complicated by cardiogenic shock were studied.

RESULTS

The in-hospital mortality rate was 53%. Variables with significant univariable association with in-hospital death included patency of the infarct-related artery, patient age, lowest cardiac index, highest arteriovenous oxygen difference and left main coronary artery disease. The most important independent predictors of in-hospital death were patency of the infarct-related artery, cardiac index and peak creatine kinase, MB fraction. The mortality rate in patients with patent infarct-related arteries was 33% versus 75% in those with closed arteries and 84% in those in whom arterial patency was unknown. Patients who survived to hospital discharge were followed up for a median of 2 years, with a mortality rate of 18% after 1 year. The best descriptors of the relation between these variables and postdischarge mortality included age, peak creatine kinase, ejection fraction and patency of the infarct-related artery.

CONCLUSIONS

In a large consecutive series of patients with cardiogenic shock with complete follow-up, patency of the infarct-related artery was most strongly associated with in-hospital and long-term mortality. This finding supports an aggressive interventional strategy in patients with cardiogenic shock.

Early revascularization improves survival in cardiogenic shock complicating acute myocardial infarction

The effects of coronary revascularization by percutaneous transluminal coronary angioplasty or coronary bypass grafting, or both, on survival were evaluated in 81 patients with cardiogenic shock complicating acute myocardial infarction. Thirty-two patients had successful revascularization and 49 patients had unsuccessful or no revascularization. Revascularization was achieved by coronary angioplasty in 22 patients, coronary bypass surgery in 2 and angioplasty followed by bypass surgery in 8. No significant differences were noted between the two groups with regard to baseline clinical or hemodynamic variables. Intraaortic balloon counterpulsation was employed in 27 (84%) of the 32 patients in the group with revascularization and in 19 (39%) of the 49 patients without revascularization (p = 0.0006). The in-hospital survival was significantly better in the patients with--18 (56%) of 32--than in the patients without revascularization--4 (8%) of 49 (p less than 0.0001). At a mean follow-up period of 21 +/- 15 months, this survival difference persisted--16 (50%) of 32 patients with revascularization survived versus 1 (2%) of 49 patients without revascularization (p less than 0.0001). The mean time from the onset of shock to revascularization differed significantly between survivors (12.4 +/- 15 h) and nonsurvivors (58.5 +/- 93 h) in the group with revascularization (p = 0.0004). In the revascularization group, the in-hospital survival rate was 77% (17 of 22) when revascularization was performed within 24 h but only 10% (1 of 10) when it was performed after 24 h (p = 0.0006).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical impact of introducing thrombolytic and aspirin therapy into the management policy of a coronary care unit

PURPOSE

To evaluate the impact of introducing thrombolytic and aspirin therapy into the management policy of a coronary care unit, with particular reference to its effects on the hospital course of nonselected patients with acute myocardial infarction. End points chosen were the utilization of thrombolytic and aspirin therapy, hospital mortality, discharge diuretic requirements, and the incidence of ventricular fibrillation and cardiogenic shock.

PATIENTS AND METHODS

A total of 336 patients with acute myocardial infarction were studied, comprising consecutive admissions to the coronary care unit over two separate 12-month periods: January to December 1986 (n = 158) and September 1989 to August 1990 (n = 178), before and after thrombolytic and aspirin therapy had been introduced into the management policy of the unit.

RESULTS

Thrombolytic and aspirin therapy was given to 87% and 93%, respectively, of all patients in the 1989/1990 cohort. This high treatment rate led to substantial improvements in morbidity and mortality. Thus, comparison of the 1986 and 1989/1990 cohorts showed reductions in hospital mortality (24% to 11%, p less than 0.005), ventricular fibrillation (22% to 13%, p = 0.05), and cardiogenic shock (20% to 6%, p less than 0.001), particularly in patients aged over 60. Reductions in the incidence of lesser degrees of heart failure are reflected in the proportions of patients discharged with diuretic requirements, which declined from 43% in 1986 to 22% in 1989/1990 (p less than 0.001). The duration of hospital stay for patients who survived showed no change between 1986 and 1989/1990, but time spent in the coronary care unit decreased from 3.1 +/- 1.8 to 2.1 +/- 1.4 days (p less than 0.001).

CONCLUSION

The great majority of nonselected patients with acute myocardial infarction are candidates for thrombolytic and aspirin therapy, which can be given safely, leading to profound reductions in mortality and the incidence of major complications, particularly in the older age group.

Percutaneous transluminal coronary angioplasty in patients with cardiogenic shock

In cardiogenic shock complicating acute myocardial infarction, percutaneous transluminal coronary angioplasty has been reported to significantly improve the modest survival benefits afforded by emergency surgical revascularization and thrombolytic therapy. The records of all patients who underwent angioplasty for acute myocardial infarction complicated by cardiogenic shock were retrospectively reviewed to determine whether coronary angioplasty improves survival. Of the 45 patients, 28 (group 1, 62%) had successful dilation of the infarct-related artery and 17 (group 2, 38%) had unsuccessful angioplasty. The groups were similar in extent of coronary artery disease, infarct location, incidence of multivessel disease and hemodynamic variables. The overall hospital survival rate was 56% (71% in group 1 and 29% in group 2). Group 1 patients had more left main coronary artery disease, and group 2 patients were older and had a higher incidence of prior myocardial infarction. Multivariate analysis showed that the survival advantage in patients with successful angioplasty was statistically significant (p = 0.014) when these factors were taken into account. At a mean follow-up interval of 2.3 years (range 1 month to 5.6 years), there were five deaths (four cardiac and one noncardiac), for a 2.3-year survival rate of 80% in patients surviving to hospital discharge. During the follow-up period, 36% of hospital survivors had repeat hospitalization for cardiac evaluation, 8% had myocardial infarction, 8% had coronary artery bypass surgery and 24% had angina.

Cardiogenic shock after acute myocardial infarction. Incidence and mortality from a community-wide perspective, 1975 to 1988

BACKGROUND

Cardiogenic shock resulting from acute myocardial infarction is a serious complication with a high mortality rate, but little is known about whether its incidence or outcome has changed over time. As part of an ongoing population-based study of acute myocardial infarction, we examined trends over time in the incidence and mortality rate of cardiogenic shock after acute myocardial infarction.

METHODS

We studied 4762 patients with acute myocardial infarction who were admitted to 16 hospitals in the Worcester, Massachusetts, metropolitan area between 1975 and 1988. We determined the incidence of and short-term and long-term mortality due to cardiogenic shock in each of six years during this study period.

RESULTS

The incidence of cardiogenic shock complicating acute myocardial infarction remained relatively constant, averaging 7.5 percent. Multivariate regression analysis that controlled for variables affecting incidence revealed significant though inconsistent temporal trends in the incidence of cardiogenic shock. As compared with the risk in 1975, the adjusted relative risk (with 95 percent confidence interval) was 0.83 (0.54 to 1.28) in 1978, 0.96 (0.63 to 1.48) in 1981, 0.68 (0.42 to 1.12) in 1984, 1.16 (0.70 to 1.92) in 1986, and 1.65 (0.99 to 2.77) in 1988. The overall in-hospital mortality rate among patients with cardiogenic shock was significantly higher than that among patients without this complication (77.7 percent vs. 13.5 percent, P less than 0.001). The in-hospital mortality among the patients with shock did not improve between 1975 (73.7 percent) and 1988 (81.7 percent). Long-term survival during the 14-year follow-up period was significantly worse among patients who survived cardiogenic shock during hospitalization than among patients who did not have shock (P less than 0.001).

CONCLUSIONS

The results of this observational, community-wide study suggest that neither the incidence nor the prognosis of cardiogenic shock resulting from acute myocardial infarction has improved over time. Both in-hospital and long-term survival remain poor for patients with this complication.

Early angioplasty in patients with acute myocardial infarction complicated by hypotension

Emergency percutaneous transluminal coronary angioplasty was performed in 62 patients with acute myocardial infarction complicated by hypotension. All patients were treated within 12 hours of the onset of chest pain. Angioplasty was completely successful (residual lesion less than or equal to 50%) in 48 patients, partially successful (patent vessel greater than 50% residual lesion) in four patients, and unsuccessful in 10 patients. Patients in whom angioplasty was successful had a hospital mortality rate of 19%; those in whom angioplasty was unsuccessful or only partially successful had hospital mortality rates of 60% and 50%, respectively, (p = 0.012). Patients with occlusion of the proximal left anterior descending vessel had the highest failure rate (42%) and the highest mortality rate (67%). Other univariate predictors of hospital mortality were older age and elevated end-diastolic pressure. Successful emergency angioplasty improves mortality in patients with acute infarction complicated by hypotension.

Mechanism of shock associated with right ventricular infarction

Various mechanisms have been proposed to explain the shock sometimes associated with right ventricular infarction, but only small numbers of patients with clinical shock have been studied. The haemodynamic profiles of seven patients with clinical cardiogenic shock after right ventricular myocardial infarction were studied prospectively. They were selected because all had a stable cardiac rhythm and none had absolute hypovolaemia during the study period. In all of them the mean right atrial pressure exceeded the pulmonary artery occlusion pressure. After treatment with varying combinations of dopamine, dobutamine, and glyceryl trinitrate (titrated to achieve the optimum haemodynamic response) the mean systemic arterial pressure increased, as did the cardiac index. There was an associated increase in the left ventricular stroke work index but the right ventricular stroke work index was unchanged. There was no significant change in heart rate, mean right atrial pressure, or pulmonary artery occlusion pressure. This suggests that the probable mechanism of the shock associated with right ventricular infarction is concomitant severe left ventricular dysfunction.