Age-related increase in mortality among patients with first myocardial infarctions treated with thrombolysis. The Investigators of the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI-2)

Impact of sex and its interaction with age on the management of and outcome for patients with acute myocardial infarction in 4 Japanese hospitals

BACKGROUND

Several studies from the United States and from European countries have detected sex and age differences in clinical characteristics, management, and outcomes of acute myocardial infarction. The aim of this study was to determine how sex and age influence the management of and outcome for patients with acute myocardial infarction in Japan.

METHODS

A retrospective cohort study was performed by means of patient chart review at 4 teaching hospitals in Japan. There was a total of 482 patients (136 females [28%], 346 males [72%]) admitted consecutively with a diagnosis of acute myocardial infarction between July, 1995 and June, 1996.

RESULTS

Female patients were older and had more comorbid diseases than male patients. Female patients also tended to have more cardiac complications during hospitalization and a greater 30-day mortality (10% vs 4%, P <.05). After adjustment for baseline characteristics and age/sex interaction, it was found that female patients were less likely to undergo thrombolytic therapy, cardiac catheterization, or revascularization, and they had a greater 30-day mortality. These sex differences in cardiac catheterization and revascularization were more pronounced for older patients. On the other hand, the sex differences in 30-day mortality were greater for younger patients.

CONCLUSIONS

Our data suggest that cardiac catheterization, revascularization and 30-day mortality may have been related to patient sex and age, but further study is needed.

Reperfusion therapy in elderly patients with acute myocardial infarction: a randomized comparison of primary angioplasty and thrombolytic therapy

OBJECTIVES

This study sought to determine the short- and long-term outcome of primary coronary angioplasty and thrombolytic therapy for acute myocardial infarction (AMI) in patients older than 75 years of age.

BACKGROUND

The benefit of reperfusion therapy in elderly patients with AMI is uncertain, although elderly people account for a large proportion of deaths.

METHODS

We randomly assigned a total of 87 patients with an AMI who were older than 75 years to treatment with angioplasty or intravenous (IV) streptokinase. Clinical outcome was measured by taking the end points of death and the combination of death, reinfarction or stroke during follow-up.

RESULTS

The primary end point, a composite of death, reinfarction or stroke, at 30 days had occurred in 4 (9%) patients in the angioplasty group as compared with 12 (29%) in the thrombolysis group (p = 0.01, relative risk [RR]: 4.3, 95% confidence interval [CI]: 1.2 to 20.0). At one year the corresponding figures were 6 (13%) and 18 (44%), respectively (p = 0.001, RR: 5.2, 95% CI: 1.7 to 18.1).

CONCLUSIONS

In this series of patients with AMI who were older than 75 years, primary coronary angioplasty had a significant clinical benefit when compared with IV streptokinase therapy.

Cardioprotective effect of ischemic preconditioning is preserved in food-restricted senescent rats

Ischemic preconditioning (PC) has been proposed as an endogenous form of protection against-ischemia reperfusion injury. We have shown that PC does not prevent postischemic dysfunction in the aging heart. This phenomenon could be due to the reduction of cardiac norepinephrine release, and it has also been previously demonstrated that age-related decrease of norepinephrine release from cardiac adrenergic nerves may be restored by caloric restriction. We investigated the effects on mechanical parameters of PC against 20 min of global ischemia followed by 40 min of reperfusion in isolated hearts from adult (6 mo) and "ad libitum"-fed and food-restricted senescent (24 mo) rats. Norepinephrine release in coronary effluent was determined by high-performance liquid chromatography. Final recovery of percent developed pressure was significantly improved after PC in adult hearts versus unconditioned controls (85.2 +/- 19% vs. 51.5 +/- 10%, P < 0.01). The effect of PC on developed pressure recovery was absent in ad libitum-fed rats, but it was restored in food-restricted senescent hearts (66.6 +/- 13% vs. 38.3 +/- 11%, P < 0.05). Accordingly, norepinephrine release significantly increased after PC in both adult and in food-restricted senescent hearts, and depletion of myocardial norepinephrine stores by reserpine abolished the PC effect in both adult and in food-restricted senescent hearts. We conclude that PC reduces postischemic dysfunction in the hearts from adult and food-restricted but not in ad libitum-fed senescent rats. Despite the possibility of multiple age-related mechanisms, the protection afforded by PC was correlated with increased norepinephrine release, and it was blocked by reserpine in both adult and food-restricted senescent hearts. Thus caloric restriction may restore PC in the aging heart probably via increased norepinephrine release.

The significance of depression in older patients after myocardial infarction

OBJECTIVES

Depression is common in patients recovering from a myocardial infarction (MI) and is an independent risk factor for early mortality. Although most patients with MI are aged 65 and older, there is little information about post-MI depression in this age group. This study was performed to determine the significance of post-MI depression in individuals aged 65 and older.

DESIGN

A cohort study of hospitalized patients and a telephone interview 4 months later.

SETTING

A university-affiliated teaching hospital in Baltimore, Maryland.

PARTICIPANTS

Patients admitted with an acute MI (N = 284), 153 (53.9%) of whom were aged 65 and older; 101 of these (66.0%) completed the 4-month follow-up interview.

MEASUREMENTS

Patients were interviewed 3 to 5 days post-MI to evaluate for the presence of symptoms of depression (a score of > or =10 on the Beck Depression Inventory and for the presence of mood disorder using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Revised, Third Edition. Survivors were then interviewed by telephone 4 months after discharge to assess adherence to recommendations to reduce cardiac risk by using the Medical Outcomes Study Specific Adherence Scale. Comorbidities and prescribed medications were determined by review of hospital charts and computerized medical records.

RESULTS

Older patients with depression were more likely to die in the first 4 months than older patients without depression (26.5% vs 7.3%, P =.002). Older patients with depression were also more likely than older patients without depression to have had a prior MI (54.3% vs 31.0%, P =.012) and were somewhat more likely to have chronic lung disease (28.6% vs 14.4%, P =.054), a non-Q wave MI (88.6% vs 72.8%, P =.054), diabetes mellitus (48.6% vs 32.5%, P =.082), and a left ventricular ejection fraction below 35% (50.0% vs 33.3%, P =.084). Compared with older patients without depression, depressed older patients were also marginally less likely at discharge to be prescribed a beta-blocker (74.3% vs 86.3%, P =.092) or a lipid-lowering agent (31.4% vs 49.6%, P =.059). Depressed patients aged 65 and older were less likely to adhere to a low-fat/low-cholesterol diet (P <.01) or a diabetic diet (P <.01), or to be taking prescribed medications (P <.05), exercising regularly (P <.01), reducing stress (P <.01), and increasing social support (P <.01).

CONCLUSION

Depression is prevalent after an acute MI in patients aged 65 and older. Older post-MI patients with depression have more comorbidities than older patients without depression and have almost four times the risk of dying within the first 4 months after discharge. Although this increased risk is likely to be related to many factors, our data suggest that sicker patients who are older and depressed may less often be prescribed medications known to reduce post-MI mortality and may also have greater difficulty following recommendations to reduce cardiac risk than their counterparts without depression. Efforts to improve adherence to post-MI treatment guidelines and to enhance patient compliance may improve prognosis in this high-risk group.

Efficacy of thrombolysis in younger and older adult patients suffering their first acute q-wave myocardial infarction

OBJECTIVES

Advancing age is an independent predictor of increased mortality after acute myocardial infarction (AMI). Several hypotheses have been developed to try to explain this phenomenon, but data available about the efficacy of thrombolytic therapy in older patients are still not conclusive. The goal of this study was to investigate the efficacy of thrombolysis in adult and older patients who suffered their first AMI.

DESIGN

Retrospective cohort study.

SETTING

A coronary care unit.

PARTICIPANTS

The sample included 244 younger (aged <65, n = 166) and older (age 65, n = 78) adult patients suffering their first Q-wave AMI, all receiving thrombolysis with human-recombinant tissue-type plasmin-ogen activator (100 mg total dose within 2.5 hours of the onset of AMI.

MEASUREMENTS

Infarct size was estimated by isoenzyme creatine kinase-myoglobin (CK-MB) release, measuring the area under the curve as a function of time. ST elevation, the sum of ST elevation above the baseline, and the sum of R wave height in precordial leads V1-V6 were evaluated using 12-lead electrocardiograms. Myocardial reperfusion was calculated when ST-segment elevation decreased more than 60 with respect to the most abnormal peak detected.

RESULTS

CK-MB peak level was significantly smaller in younger patients than in older ones (P< .01) and was significantly correlated with increasing age (P< .0001). Area under the 36-hour CK-MB curve was lower in younger patients than in older ones (P< .0001) and was well correlated with increasing age (P< .01). Reperfusion time was significantly shorter in younger patients (P< .05), and age was significantly correlated with reperfusion time (P< .001).

CONCLUSIONS

Infarct size was greater and reperfusion time was longer in older patients than in younger ones with first Q-wave AMI treated with thrombolysis. Infarct size and reperfusion time were linearly correlated with increasing age. These findings may help explain the increase in mortality due to AMI observed with advancing age.

Loss of preconditioning by attenuated activation of myocardial ATP-sensitive potassium channels in elderly patients undergoing coronary angioplasty

BACKGROUND

The ischemic preconditioning response among elderly patients is known to be lower than in adult patients. Since mitochondrial ATP-sensitive potassium (K(ATP)) channels exert preconditioning effects, we undertook this study to determine whether this attenuated activation of K(ATP) channels influences the reduced responsiveness of elderly patients to ischemic preconditioning.

METHODS AND RESULTS

Fifty-six patients undergoing angioplasty for a major epicardial coronary artery were randomly allocated to either an ischemic preconditioning group, a nicorandil (an agonist of K(ATP) channels) group, or a glibenclamide (an antagonist of K(ATP) channels), group based on their age: adult groups (n=26; age, </=55 years; mean age, 45+/-5 years) and elderly groups (n=30; age, >/=65 years; mean age, 71+/-3 years). Ischemic preconditioning with a 120-second coronary occlusion significantly lowered the ischemic burden assessed by ST-segment shift, chest pain score, and myocardial lactate extraction ratios in the adult group. This did not occur in the elderly group. The impaired preconditioning responsiveness in the elderly patients was reversed by nicorandil administration or an ischemic period lengthened to 180 seconds. However, nicorandil-induced cardioprotection was abolished by administering glibenclamide in both the adult and elderly groups.

CONCLUSIONS

The present study demonstrates that preconditioning significantly enhances the tolerance of the heart to subsequent ischemia in adults but not in senescent patients. Since prolonged ischemia and nicorandil are able to mimic preconditioning and can reverse impaired responsiveness, impaired preconditioning of the aged heart appears to be due to an attenuated activation of K(ATP) channels.

Myocyte renewal and ventricular remodelling

Remaining young at heart is a desirable but elusive goal. Unbeknown to us, however, myocyte regeneration may accomplish just that. Continuous cell renewal in the adult myocardium was thought to be impossible, but multipotent cardiac stem cells may be able to renew the myocardium and, under certain circumstances, can be coaxed to repair the broken heart after infarction.

Age-related changes in venticular-arterial coupling: pathophysiologic implications

The interaction of the heart with the systemic vasculature, termed ventricular-arterial coupling, is a central determinant of net cardiovascular performance. The capacity of the body to augment cardiac output, regulate systemic blood pressure, and respond appropriately to elevations in heart rate and venous filling volume is related as much to the properties of the heart as it is the vasculature into which the heart ejects. With aging, changes in the arterial system associated with vascular stiffening and a reduction in peripheral vasomotor regulation can profoundly affect this coupling by imposing far greater pulsatile and late-systolic loads on the heart. This is accompanied by tandem increases in left ventricular end-systolic stiffness (end-systolic chamber elastance) and reduced diastolic compliance. Altered coupling related to combined ventricular-vascular stiffening increases blood pressure lability for a given change in hemodynamic loading and heart rate (i.e. under stress demands), as well as reduces the capacity to enhance cardiac output without greatly increasing cardiac wall stress. Furthermore, such coupling influences myocardial perfusion by elevating the proportion of coronary flow during the systolic time period. This more closely links ventricular systolic function with myocardial flow, and can compromise flow reserve and exacerbate ischemic dysfunction when ventricular systolic function declines, such as with concomitant heart failure or acute regional ischemia. This article reviews the theory behind ventricular-arterial coupling analysis, the changes in coupling that occur with age and their impact on normal reserve mechanisms, and the likely role of these changes have on heart failure and ischemic heart disease and disease therapy in the elderly.

High level of physical activity preserves the cardioprotective effect of preinfarction angina in elderly patients

OBJECTIVES

The study investigated the effects of physical activity on preinfarction angina, a clinical equivalent of ischemic preconditioning (PC), in adult and elderly patients with acute myocardial infarction (AMI).

BACKGROUND

Preinfarction angina seems to confer protection against in-hospital mortality in adult but not in elderly patients. However, it has been experimentally demonstrated that exercise training restores the protective effect of PC in the aging heart.

METHODS

We retrospectively verified whether physical activity preserved the protective effect of preinfarction angina against in-hospital mortality in 557 elderly patients with AMI. Physical activity was quantified according to the Physical Activity Scale for the Elderly (PASE).

RESULTS

In-hospital mortality was 22.2% in elderly patients with preinfarction angina and 27.2% in those without (p = 0.20). When the PASE score was stratified in quartiles (0 to 40, 41 to 56, 57 to 90, >90), a high score was strongly associated with reduced in-hospital mortality (30.8%, 32.2%, 17.2% and 15.3%, respectively, p < 0.001 for trend). Interestingly, a high level of physical activity reduced in-hospital mortality in elderly patients with preinfarction angina (35.7%, 35.4%, 12.3% and 4.23%, respectively, p < 0.001 for trend) but not in those without (23.0%, 27.2%, 26.0% and 35.0%, respectively, p = 0.35 for trend). Accordingly, the protective role of preinfarction angina on in-hospital mortality was present only in elderly patients showing a high level of physical activity (adjusted odds ratio, 0.09; 95% confidence interval, 0.01 to 0.57; p < 0.05).

CONCLUSIONS

Physical activity and not preinfarction angina protects against in-hospital mortality in elderly patients with myocardial infarction. Nevertheless, the protective effect of preinfarction angina is preserved in elderly patients with a high level of physical activity.

Age and gender effects on cardiomyocyte apoptosis in the normal human heart

BACKGROUND

Animal studies have suggested that apoptosis could play a significant role in the myocardial aging process. Although no information is available in humans, the paradigm that cardiomyocyte apoptosis is increased in the aged human heart has been widely propagated. Moreover, it is unknown whether gender differences may influence cardiomyocyte apoptosis.

METHODS

Cardiomyocyte apoptosis was compared between subjects ranging in age from 21 to 93 years (22 men and 19 women), free of any cardiovascular disease, who died of either violent or natural causes. Strict inclusion and exclusion criteria were used to ensure that the selected hearts accurately represented normal aging.

RESULTS

Apoptosis was detected using the TdT-mediated dUTP digoxigenin nick end labeling (TUNEL) technique (controls for TUNEL included negative staining for splicing factor SC-35 and for Ki-67 antigen). The percentage of cardiomyocyte death ranged from 0% to 0.0437%, with no correlation with the age of the subject (p =.85). However, the percentage of apoptosis was threefold higher in men than in women (0.0133% +/- 0.0030% vs 0.0042% +/- 0.0008%, respectively; p <.01).

CONCLUSIONS

Our results in humans do not support the hypothesis that aging influences the percentage of cardiomyocyte apoptosis. However, gender appears to be an important determinant of the occurrence of apoptosis.

Clinical manifestations of acute myocardial infarction in older patients

Coronary artery disease is the major cause of morbidity and mortality in the elderly in the United States. In this age group, the clinical presentation of coronary heart disease can be quite atypical. In general, the incidence of typical precordial chest pressure/pain denoting myocardial ischemia is less common, whereas dyspnea as an anginal-equivalent symptom is frequent. The diagnosis of ischemic cardiac pain is frequently confused by the many comorbid conditions present in the elderly. Even when classic ischemic precordial discomfort is present, it tends to be less severe and less well defined. The elderly appear to have reduced pain perception; as a result, silent myocardial ischemia is more common and carries a somewhat worse prognosis in the elderly than in younger age groups. Similarly, the presenting symptoms of acute myocardial infarction in the elderly can be nonspecific. The classic crushing substernal chest pain decreases with age, whereas the symptom of dyspnea gradually increases. Neurologic symptoms, confusional states, weakness, and worsening heart failure are common clinical presentations of an acute infarction in elderly patients. Silent (unrecognized) myocardial infarctions are common in the elderly and carry serious prognostic implications.

Effect of aging on the ability of preconditioning to protect rat hearts from ischemia-reperfusion injury

Ischemic preconditioning (IP) reduces infarct size in young animals; however, its impact on aging is underinvestigated. The effect of variations in IP stimuli was studied in young, middle-aged, and aged rat hearts. Isolated hearts underwent 35 min of regional ischemia and 120 min of reperfusion. Hearts with IP were subjected to either one ischemia-reperfusion cycle (5 min of ischemia and 5 min of reperfusion per cycle) or three successive cycles before 35 min of regional ischemia. Additional studies investigated the effects of pharmacological preconditioning in aged hearts using the adenosine A(1) receptor agonist 2-chloro-N(6)-cyclopentyladenosine, the protein kinase C analog 1,2-dioctanoyl-sn-glycerol, and the mitochondrial ATP-sensitive potassium (K(ATP))-channel opener diazoxide. Infarct sizes indicated that the aged rat heart could not be preconditioned via ischemic or pharmacological means. The middle-aged rat heart had a blunted IP response compared with the young adult (only an increased IP stimulus caused a significant reduction in infarct size). These results suggest that there are defects within the IP signaling cascade of the aged heart. Clinical relevance is important if we are to use any IP-like mimetics to the benefit of an aging population.

Acute myocardial infarction in the elderly: differences by age

OBJECTIVES

We evaluated the clinical characteristics and outcomes of elderly patients hospitalized with acute myocardial infarction (AMI) to describe differences by age.

BACKGROUND

Elderly patients with AMI are perceived as a homogeneous population, though the extent by which clinical characteristics vary among elderly patients has not been well described.

METHODS

Data from 163,140 hospital admissions of Medicare beneficiaries age > or =65 years between 1994 and 1996 with AMI at U.S. hospitals were evaluated for differences in clinical characteristics and mortality across five age-based strata (in years): 65 to 69, 70 to 74, 75 to 79, 80 to 84 and > or =85.

RESULTS

Older age was associated with a greater proportion of patients with functional limitations, heart failure, prior coronary disease and renal insufficiency and a lower proportion of male and diabetic patients. Of note, the proportion of patients presenting with chest pain within 6 h of symptom onset, and with ST-segment elevation, was lower in each successive age group. Thirty-day mortality rates were higher in older age groups (65 to 69: 10.9%, 70 to 74: 14.1%, 75 to 79: 18.5%, 80 to 84: 23.2%, > or =85: 31.2%, p = 0.001 for trend). The effect of age persisted but was attenuated after adjustment for differences in patient characteristics; similar trends were observed for one-year mortality.

CONCLUSIONS

Our data indicate significant age-associated differences in clinical characteristics in elderly patients with AMI, which account for some of the age-associated differences in mortality. The practice of grouping older patients together as a single age group may obscure important age-associated differences.

Age-related responses of the microcirculation to ischemia-reperfusion and inflammation

Aging is a major risk factor for a variety of ischemic disorders including ischemic heart disease and stroke. Intense research over the past decade into ischemia-reperfusion (I/R) injury has implicated a general mechanism whereby reactive oxygen species produced at the onset of reperfusion overwhelm endogenous antioxidants, resulting in a cascade of events including mast cell degranulation, recruitment of neutrophils to the endothelial wall, arteriolar constriction that limits tissue perfusion, and increased vascular permeability that leads to inflammation and edema. Much of our knowledge regarding I/R injury comes from animal models; however, despite the fact that I/R disproportionately affects older individuals, young animals are usually chosen in models of I/R injury due to their greater availability, lower cost, and fewer health problems. Results obtained from young animals demonstrate a central role for both neutrophils and mast cells in I/R-induced increases in microvascular permeability and arteriolar constriction; however, it is not clear that a role for neutrophils is extended to older animals. A growing body of evidence indicates that neutrophils isolated from elderly individuals exhibit attenuated chemotaxis, oxidant release, and phagocytosis, and it has been suggested that these deficiencies are related to an age-associated increase in glucocorticoid production and oxidative stress. Therefore, neutrophils may have a limited capacity to influence microcirculatory tissue in the elderly compared to in the young. In support of this hypothesis, I/R-induced increases in microvascular permeability and decreases in vascular perfusion have been found to occur in older rats despite the absence of a significant increase in leukocyte-endothelial cell adhesion. Furthermore, elimination of circulating neutrophils attenuates I/R-induced mesenteric permeability only in young rats. Therefore, it appears that neutrophil-independent mechanisms of inflammation may be responsible for much of the microvascular dysfunction initiated by I/R in older animals.

Exercise rehabilitation of older patients with cardiovascular disease

As the population of elderly patients with cardiovascular disease continues to increase, much research needs to be done with the goal of maintaining physical functioning and personal independence in this population. It is of particular importance to determine whether training programs can improve physical functioning in the most severely disabled older coronary patients. Effects of cardiac rehabilitation programs on other outcome measures, including psychosocial outcomes, lipid levels, insulin levels, and body composition require better study. Finally, the economic benefits of cardiac rehabilitation in the older coronary patients has received little attention, although early reports are promising. In summary, the older population with coronary disease is characterized by high rates of disability. Exercise training has been demonstrated to be safe and to improve strength, aerobic fitness capacity, endurance and physical function. It remains to be seen whether exercise training can reverse or prevent disability in a broad population of older patients with cardiovascular disease. If successful, cardiac rehabilitation programs will pay great medical, social, and economic dividends in this population.

Increased calcium vulnerability of senescent cardiac mitochondria: protective role for a mitochondrial potassium channel opener

In senescence, endogenous mechanisms of cardioprotection are apparently attenuated resulting in increased vulnerability to ischemia-reperfusion. In particular, mitochondria, which are essential in maintaining cardiac energetic and ionic homeostasis, are susceptible to Ca2+ overload, a component of metabolic injury. However, effective means of protecting senescent mitochondria are lacking. Here, mitochondrial function and structure were assessed using ion-selective mini-electrodes, high-performance liquid chromatography and electron microscopy. Aging decreased ADP-induced oxygen consumption and prolonged the time associated with ADP to ATP conversion, which manifested as a reduced rate of oxidative phosphorylation. Aging also reduced mitochondrial Ca2+ handling, and increased Ca2+-induced mitochondrial damage. Diazoxide, a potassium channel opener, reduced Ca2+ loading and protected the functional and structural integrity of senescent mitochondria from Ca2+-induced injury. In this way, the present study identifies the potential usefulness for pharmacotherapy in protecting vulnerable senescent mitochondria from conditions of Ca2+ overload, such as ischemia-reperfusion.

Symptom predictors of acute coronary syndromes in younger and older patients

BACKGROUND

Symptoms, a key element in the patient's decision to seek care, are critical to appropriate triage, and influence decisions to pursue further evaluation and initiation of treatment. Although many studies have described symptoms associated with acute coronary syndromes (ACS), few, if any, have examined symptom predictors of ACS and whether they differ by patients' age.

OBJECTIVES

To explore symptom predictors of ACS in younger (< 70 years) and older (> or = 70 years) patients. To test the hypothesis that typical symptoms are predictive of ACS in younger patients, but are less predictive in older patients.

METHOD

Secondary analysis of observational data gathered on 531 patients presenting to the emergency department of a regional cardiac referral center in New England with symptoms suggestive of ACS.

RESULTS

Bivariate analyses revealed no symptoms significantly (p < .01) associated with ACS in older patients. In younger patients presence of chest symptoms and the total number of typical symptoms reported were significantly (p < .01) associated with ACS. After adjustment for age and gender, typical symptoms that were positive predictors of ACS in younger patients included chest symptoms (OR 2.37, 95% CI 1.32-4.27, p = .004) and arm pain (OR 1.78, 95% CI 1.03-3.09, p = .040). Additionally, the total number of typical symptoms reported (OR 1.68, 95% CI 1.31-2.15, p < .001) was a positive predictor of ACS in younger patients. The atypical symptom of fatigue (OR 2.52, 95% CI 1.10-5.81, p = .029) was a significant positive predictor of ACS, whereas dizziness/faintness (OR .50, 95% CI .26-.91, p = .024) was a significant negative predictor of ACS in younger patients. Logistic regression analysis using the entire sample revealed an interaction between age and number of typical symptoms indicating that younger patients had a 36% greater odds for ACS for each additional typical symptom present compared with older patients (OR 1.36, 95% CI 1.02-1.83, p = .038 for interaction between age and number of typical symptoms reported). The model with the interaction between age and chest symptoms revealed a borderline association (p = .10 for the interaction between age and chest symptoms), with younger patients being more likely than older patients to report chest symptoms.

CONCLUSIONS

Typical symptoms are predictive of ACS in younger patients and less predictive in older patients.

PITFALLS IN THE EMERGENCY DEPARTMENT DIAGNOSIS OF ACUTE MYOCARDIAL INFARCTION

The accurate assessment and triage of patients with potential ACS is a complex decision-making process based on information that is not entirely reliable. The knowledgeable EP recognizes that assessment of patients with chest pain requires an understanding of the various clinical presentations of ACS and high-risk patient types, as well as careful use of the available modalities to diagnose these syndromes efficiently while incurring minimal risk to the patients safety. The busy EP is faced with sick patients with chest pain daily, so that it behoove anyone in emergency medicine to familiarize themselves with these diagnostic pitfalls.

Long-term mortality rates reflect progressive prognostic benefits of thrombolysis in patients with first acute myocardial infarction

This community nonrandomized study comprised a consecutive cohort of 1,545 (81% males) < or = 65-year-old patients who survived a first acute myocardial infarction (AMI). The all-cause 4- to 5-year mortality rate was 9% (80% cardiac). Univariate analysis revealed that older age, female gender, hypertension, diabetes, not undergoing thrombolysis, higher Killip class, preinfarction heart disease, peripheral vascular disease (PVD) and chronic obstructive lung disease (COLD) were significantly associated with increased mortality. Multivariate analyses disclosed the latter five parameters as being independent predictors of mortality. Our results show that patients undergoing thrombolysis enjoyed a progressive prognostic benefit over time. The independent contribution of PVD and COLD to long-term mortality is highlighted, in addition to the contribution of thrombolytic therapy, Killip class, and heart disease prior to infarction as being important predictors of long-term mortality in patients with a first AMI.

Cardiologic problems in the post acute ventilated patient

Chronically critically ill patients who develop acute respiratory failure commonly have complicating cardiac pathology that may or may not be evident at initial evaluation. The acute coronary syndromes should be excluded in all patients presenting with respiratory failure. Cardiac rhythm disturbances are common and should be actively investigated and treated in all critically ill patients. Heart failure is common in the chronically critically ill patient but usually responds to early diagnosis and prompt treatment. Finally, cardiogenic shock carries a poor prognosis in most patient subsets except when it is caused by cardiac tamponade. The intensivist must be vigilant for cardiac pathology complicating the recovery of patients with acute respiratory illness and initiate the search for correctable problems that may precipitate further episodes of respiratory insufficiency.

Prognostic modeling with logistic regression analysis: in search of a sensible strategy in small data sets

Clinical decision making often requires estimates of the likelihood of a dichotomous outcome in individual patients. When empirical data are available, these estimates may well be obtained from a logistic regression model. Several strategies may be followed in the development of such a model. In this study, the authors compare alternative strategies in 23 small subsamples from a large data set of patients with an acute myocardial infarction, where they developed predictive models for 30-day mortality. Evaluations were performed in an independent part of the data set. Specifically, the authors studied the effect of coding of covariables and stepwise selection on discriminative ability of the resulting model, and the effect of statistical "shrinkage" techniques on calibration. As expected, dichotomization of continuous covariables implied a loss of information. Remarkably, stepwise selection resulted in less discriminating models compared to full models including all available covariables, even when more than half of these were randomly associated with the outcome. Using qualitative information on the sign of the effect of predictors slightly improved the predictive ability. Calibration improved when shrinkage was applied on the standard maximum likelihood estimates of the regression coefficients. In conclusion, a sensible strategy in small data sets is to apply shrinkage methods in full models that include well-coded predictors that are selected based on external information.

Does angina the week before protect against first myocardial infarction in elderly patients?

Mortality rates for coronary artery disease are greater in elderly patients. Although prodromal angina occurring shortly before an acute myocardial infarction (MI) has protective effects against ischemia, this effect has not been well documented in older patients. This study investigated whether angina 1 week before a first MI provides protection in this group of patients. A total of 290 consecutive elderly (>64 years old, n = 143) and adult patients (<65 years old, n = 147) with a first MI were examined to assess the effect of preceding angina on the short- and long-term prognosis. Elderly patients with a history of prodromal angina were less likely than those without angina to experience in-hospital death, heart failure, or the combined end point of in-hospital death and heart failure (6% vs 20.4%, p = 0.02; 10% vs 23.7%, p = 0.07; 14% vs 32.3%, p = 0.01, respectively). Left ventricular function was more frequently depressed (ejection fraction <40%) in elderly patients without (44.8%) than with (26%, p = 0.04) preinfarction angina, and the incidence of arrhythmias (complete heart block and ventricular fibrillation) was greater in the former group (16.1% vs 4%, p = 0.03). Multivariate analysis confirmed that the presence of preinfarction angina was an independent predictor of in-hospital death and heart failure in older patients (odds ratio 0.28, p = 0.009). The occurrence of angina 1 week before a first MI may confer protection against in-hospital adverse outcomes, and may preserve left ventricular function in older patients.

Sex differences in risk factors, treatment and mortality after acute myocardial infarction: an observational study

BACKGROUND

Coronary heart disease is the major cause of death of postmenopausal women in industrialised countries. Although acute myocardial infarction (AMI) affects men in greater numbers, the short-term outcomes for women are worse. In the longer term, studies suggest that mortality risk for women is lower or similar to that of men. However, length of follow up and adjustment for confounding factors have varied and more importantly, the association between treatment and outcomes has not been examined.

STUDY OBJECTIVE

To investigate the association between sex differences in risk factors and hospital treatment and mortality after AMI.

DESIGN

A prospective observational study collecting demographic and clinical data on cases of AMI admitted to hospitals in Yorkshire. The main outcome measures were mortality status at discharge from hospital and two years later.

SETTING

All district and university hospitals accepting emergency admissions in the former Yorkshire National Health Service (NHS) region of northern England.

PARTICIPANTS

3684 consecutive patients with a possible diagnosis of AMI admitted to hospitals in Yorkshire between 1 September and 30 November 1995.

MAIN RESULTS

AMI was confirmed by the attending consultant for 2196 admissions (2153 people, 850 women and 1303 men). Women were older and less likely than men to be smokers or have a history of ischaemic heart disease. Crude inhospital mortality was higher for women (30% versus 19% for men, crude odds ratio of death before discharge for women 1.78, 95% confidence intervals 1.46, 2.18, p=0.00). This difference persisted after adjustment for age, risk factors and comorbidities (adjusted OR 1.29, 95% CI 1.04, 1.63, p=0.02), but was not significant when treatment was taken into account. Women were less likely to be given thrombolysis (37% versus 46%, p<0.01) and aspirin (83% versus 90%, p<0.01), discharged with beta blockers (33% versus 47%, p<0.01) and aspirin (82% versus 88% p<0.01) or be scheduled for angiography, exercise testing or revascularisation. Adjustment for age removed much of the disparity in treatment. Crude mortality rate at two years was higher for women (OR 1.81, 95%CI 1.41, 2.31, p=0.00). Age, existing risk factors and acute treatment accounted for most of this difference, with treatment on discharge having little additional influence.

CONCLUSIONS

Patients admitted to hospital with AMI should be offered optimal treatment irrespective of age or sex. Women have a worse prognosis after AMI and under-treatment of older people with aspirin and thrombolysis may be contributing to this.

[Thrombolysis in the elderly with acute myocardial infarction. The PRIAMHO study]

INTRODUCTION

In the elderly with acute myocardial infarction the risks and benefits of thrombolytic therapy are not well defined due mainly to the lack of randomized trials. In the present study we examined the clinical profile of the aged treated with thrombolytic agents and the effects of that therapy on 28 day and 1 year mortality.

PATIENTS AND METHODS

We studied 733 patients aged > 75 years (mean: 79.9) admitted to the Coronary Care Unit (CCU) of 24 Spanish hospitals with a confirmed diagnosis of Q-Wave myocardial infarction (MI). On admission, 293 patients were treated with thrombolytics and 440 patients received standard therapy. The difference between the two groups in the clinical profile of MI, treatments administered in CCU, evolutive course and 28 day and 1 year mortality were assessed.

RESULTS

The independent predictors related to the use of thrombolytic therapy were age (OR: 0.93; 95% CI: 0.89-0.97), history of arterial hypertension (OR: 0.85; 95% CI: 0.71-1.01), delay time to admission (OR: 0.998; 95% CI: 0.997-0.999), anterior location of infarct (OR: 1.21; 95% CI: 1.01-1.24) and Killip Class III-IV (OR: 0.79; 95% CI: 0.64-0.97). During the evolution thrombolysis therapy was associated with lower rates of Killip III-IV (p < 0.00001), complete AV block (p = 0.037), intraventricular conduction defects (p = 0.046) and a higher incidence of stroke (p < 0.01). The 28-day mortality was also significantly lower in the group receiving thrombolytics (27 vs 31. 3%; p = 0.035). However, this difference disappeared when the analysis was adjusted with other variables such as age, administration of aspirin and Killip Class III-IV (OR: 1.29; 95% IC: 0.87-1.92).

CONCLUSIONS

The results of this trial suggest that in the elderly with acute myocardial infarction thrombolysis is associated with a less complicated evolutive course and a lower 28-day mortality. However, these findings could be mediated by other covariables such as age, more frequent use of aspirin and a higher number of patients with Killip Class III-IV excluded from the thrombolytic therapy.

Mortality and risk indicators for death during five years after acute myocardial infarction among patients with and without ST elevation on admission electrocardiogram

We related observations in the electrocardiogram (ECG) on admission to hospital among consecutive patients hospitalized in one single hospital with acute myocardial infarction (AMI) and related the prognosis during the following 5 years to these observations.

RESULTS

Of 863 patients, 63% had ECG signs of myocardial ischemia, but only 41% had ST elevation on ED admission. Patients with ST elevation had a 5-year mortality of 44% as compared with 58% in patients without ST elevation (p < 0.001). Patients with the highest mortality were those with a pathologic ECG including signs of previous AMI, bundle branch block and pacemaker ECG, but with no ECG sign of acute ischemia. Patients with the lowest mortality were those with a nonpathologic ECG on admission.

CONCLUSION

Among consecutive patients hospitalized with AMI, less than half had ST elevation on admission to hospital. These patients had a lower mortality during 5 years of follow-up than patients without ST elevation.

Ischemic Heart Disease in the Elderly:A Need to Understand the Causes of High Mortality After Acute Myocardial Infarction

The short- and long-term mortality of patients greater than 75 years of age with acute myocardial infarction is still very high. These patients have been excluded from most randomized controlled trials designed to test interventions directed to improve the outcome of acute myocardial infarction. Contrary to young-old patients (65-74 years) in whom the benefit obtained with these interventions is even greater than that observed in younger patients, there is a lack of information concerning the optimal treatment of acute myocardial infarction in the oldest patients. Research specifically directed to assess the optimal reperfusion strategy and coadjuvant therapies in patients greater than 75 years old is critically important. The causes for such high mortality are still poorly understood. Several clinical observations suggest that old patients with acute myocardial infarction have specific pathophysiologic behaviors. As the knowledge of the mechanisms of disease is, in clinical practice, the basis of therapy development, clinical and basic research designed to elucidate the specific pathophysiological mechanisms and causes of the high mortality in the oldest patients with acute myocardial infarction should be regarded as a priority in geriatric cardiovascular research. (c) 2000 by CVRR, Inc.

Successful repair of myocardial free wall rupture after thrombolytic therapy for acute infarction

BACKGROUND

Controversy exists regarding the timing of thrombolytic administration and rupture rate.

METHODS

Hospital records at St. Luke's-Roosevelt Hospital of the 4 study patients were reviewed and compared with those of 41 patients from a group of 537 patients concurrently admitted with a diagnosis of myocardial infarction (MI).

RESULTS

Four patients experienced ventricular free wall rupture after having a MI between November 17, 1993, and July 28, 1995. All received tissue plasminogen activator. In 1 patient, pericardial effusion associated with a pseudoaneurysm was discovered in the operating room. The 3 others developed clinical pericardial tamponade before surgery. All 4 patients survived and left the hospital on postoperative days 10, 11, 11, and 82, respectively. During this same time period, 537 patients were admitted with MI, 41 of whom died; the study's 4 patients were compared with these 41.

CONCLUSIONS

These data demonstrate that rupture of the ventricular free wall can occur early after thrombolytic therapy and may have a subacute course. Prompt diagnosis and surgery offer excellent chances of surviving this fatal condition.

Cardiogenic shock due to cardiac free-wall rupture or tamponade after acute myocardial infarction: a report from the SHOCK Trial Registry. Should we emergently revascularize occluded coronaries for cardiogenic shock?

OBJECTIVES

We sought to compare the characteristics and outcomes of patients with acute myocardial infarction (MI) and cardiogenic shock (CS) caused by rupture of the ventricular free wall or tamponade versus shock from other causes.

BACKGROUND

Free-wall rupture is a recognized cause of mortality in patients with acute MI. Some of these patients present subacutely, which provides an opportunity for intervention. Recognition of factors that distinguish them from the overall shock cohort would be beneficial.

METHODS

The international SHOCK Trial Registry enrolled patients concurrently with the randomized SHOCK Trial. Thirty-six centers consecutively enrolled all patients with suspected CS after MI, regardless of trial eligibility.

RESULTS

Of the 1,048 patients studied, 28 (2.7%) had free-wall rupture or tamponade. These patients had less pulmonary edema, less diabetes, less prior MI, and less prior congestive heart failure (all p < 0.05). They more often had new Q waves in two or more leads (51.9% vs. 31.5%, p < 0.04), but MI location and time to shock onset after MI did not differ. Of patients with rupture or tamponade, 75% had pericardial effusions. No hemodynamic characteristics identified patients with rupture/tamponade. Most patients with rupture/tamponade had surgery and/or pericardiocentesis (27/28); their in-hospital survival rate was identical to that of the group overall (39.3%). Women and older patients with rupture/tamponade tended to survive intervention less often.

CONCLUSIONS

Free-wall rupture and tamponade may present as CS after MI, and survival after intervention is similar to that of the overall shock cohort. All patients with CS after MI should have echocardiography in order to detect subacute rupture or tamponade and initiate appropriate interventions.

PTX3, A prototypical long pentraxin, is an early indicator of acute myocardial infarction in humans

BACKGROUND

Inflammation is an important component of ischemic heart disease. PTX3 is a long pentraxin whose expression is induced by cytokines in endothelial cells, mononuclear phagocytes, and myocardium. The possibility that PTX3 is altered in patients with acute myocardial infarction (AMI) has not yet been tested.

METHODS AND RESULTS

Blood samples were collected from 37 patients admitted to the coronary care unit (CCU) with symptoms of AMI. PTX3 plasma concentrations, as measured by ELISA, higher than the mean+2 SD of age-matched controls (2.01 ng/mL) were found in 27 patients within the first 24 hours of CCU admission. PTX3 peaked at 7.5 hours after CCU admission, and mean peak concentration was 6.94+/-11.26 ng/mL. Plasma concentrations of PTX3 returned to normal in all but 3 patients at hospital discharge and were unrelated to AMI site or extent, Killip class at entry, hours from symptom onset, and thrombolysis. C-reactive protein peaked in plasma at 24 hours after CCU admission, much later than PTX3 (P<0.001). Patients >64 years old and women had significantly higher PTX3 concentrations at 24 hours (P<0.05). PTX3 was detected by immunohistochemistry in normal but not in necrotic myocytes.

CONCLUSIONS

PTX3 is present in the intact myocardium, increases in the blood of patients with AMI, and disappears from damaged myocytes. We suggest that PTX3 is an early indicator of myocyte irreversible injury in ischemic cardiomyopathy.

Exercise training restores ischemic preconditioning in the aging heart

OBJECTIVES

To investigate the effects of ischemic preconditioning in hearts from adult and both sedentary and trained senescent rats.

BACKGROUND

Ischemic preconditioning does not prevent postischemic dysfunction in the aging heart, probably because of reduction of cardiac norepinephrine release. Exercise training can reverse the age-related decrease of norepinephrine production.

METHODS

We investigated the effects on mechanical parameters of ischemic preconditioning against 20 min of global ischemia followed by 40 min of reperfusion in isolated perfused hearts from adult (six months) and sedentary or trained (six weeks of graduated swim training) senescent (24 months) rats. Norepinephrine release in coronary effluent was determined by high-performance liquid chromatography.

RESULTS

Final recovery of percent-developed pressure was significantly improved after preconditioning in adult hearts (91.6+/-9.6%) versus unconditioned controls (54.2+/-5.1%, p<0.01). The effect of preconditioning on developed pressure recovery was absent in sedentary but present in trained senescent hearts (39.6+/-4.1% vs. 64.3+/-7.1%, p<0.05). Norepinephrine release significantly increased after preconditioning in adult and in trained but not in sedentary senescent hearts. The depletion of myocardial norepinephrine stores by reserpine abolished preconditioning effects in adult and trained senescent hearts.

CONCLUSIONS

In adult and trained but not in sedentary senescent hearts, preconditioning reduces postischemic dysfunction and is associated with an increase in norepinephrine release. Preconditioning was blocked by reserpine in both adult and trained senescent hearts. Thus, exercise training may restore preconditioning in the senescent heart through an increase of norepinephrine release.

Early Prognostic Assessment and Treatment of Acute Myocardial Infarction in the Elderly

The progressive aging of the population is associated with an increase in the proportion of very old patients (greater than 75 years) hospitalized with acute myocardial infarction. The lack of evidence regarding the efficacy of most therapeutic interventions for acute myocardial infarction in these patients is leading to a significant degree of uncertainty in the cardiology community with respect to their optimal management. When aggressive treatment (defined as a therapeutic strategy designed to obtain and maintain a patent infarct-related coronary artery at an early moment) of acute myocardial infarction is considered in very old patients, three main questions should be addressed: why should we treat? Whom should we treat? And how should we treat? To answer these questions, the authors reviewed the data available in the literature as well as new data from the PPRIMM75 (Pronóstico del PRimer Infarto de Miocardio en Mayores de 75 aÃ+/-os) Registry, a large, prospective database of patients aged 75 years or older, admitted to a single coronary care unit in Madrid, Spain, for their first acute myocardial infarction during the last decade. (c) 2000 by CVRR, Inc.

The acute myocardial infarction in very elderly

A total 325 patients were studied at admission for myocardial infarction, measuring plasma fibrinogen (FBG), creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) and automatized hemocromocytometric parameters in order to contribute to explain the excess mortality reported in very elderly patients. It was found that age positively correlated with fibrinogen and LDH values and inversely with CPK, hemoglobin concentration and lymphocyte count. The unpaired comparison of the variables studied in age subgroups showed no differences between patients aged 65 or less than 65 years and patients aged 66-75 years. In patients aged over 75 years FBG, neutrophile count and LDH were significantly higher in respect to 65 or less and 66-75 years age subgroups and hemoglobin concentration, red blood cell count, hematocrit and lymphocyte count were lower. In the very elderly patients the study shows a biochemical feature suggesting delayed hospitalization for myocardial infarction, that may contribute to their poorer prognosis.

Lack of benefit for intravenous thrombolysis in patients with myocardial infarction who are older than 75 years

BACKGROUND

The benefit of intravenous thrombolytic therapy in elderly patients with myocardial infarction is uncertain. There are no randomized trials of thrombolytic efficacy or observational studies of clinical effectiveness that focus specifically on the elderly.

METHODS AND RESULTS

To determine whether thrombolytic therapy for elderly patients is associated with a survival advantage in a large observational database, we conducted a retrospective cohort study of 7864 Medicare fee-for-service patients aged 65 to 86 years with the primary discharge diagnosis of acute myocardial infarction who were admitted with clinical and ECG indications for thrombolytic therapy and no absolute contraindications. The study included all US acute care nongovernment hospitals without on-site angioplasty capability. Using proportional-hazards methods, we found that in a comprehensive multivariate model, there was a significant interaction (P<0.001) between age and the effect of thrombolytic therapy on 30-day mortality rates. For patients 65 to 75 years old, thrombolytic therapy was associated with a survival benefit, consistent with randomized trials. Among patients aged 76 to 86 years, thrombolytic therapy was associated with a survival disadvantage, with a 30-day mortality hazard ratio of 1.38 (95% CI 1. 12 to 1.71, P=0.003). For these patients, there was no benefit from thrombolytic therapy in any clinical subgroup.

CONCLUSIONS

In nationwide clinical practice, thrombolytic therapy for patients >75 years old is unlikely to confer survival benefit and may have a significant survival disadvantage. Reperfusion research that is focused on elderly patients is urgently needed.

Clinical trials in acute myocardial infarction: should we adjust for baseline characteristics?

BACKGROUND

Clinical trials concerning acute myocardial infarction often evaluate short-term death. Several baseline characteristics are predictors of death, most notably age. Adjustment for one or more predictors in a multivariable analysis may be considered to correct the estimate of the treatment effect for any imbalance that by chance may have occurred between the randomized groups. Moreover, adjustment results in a stratified estimate of the effect of treatment.

METHODS AND RESULTS

The effects of adjustment (correction for imbalance and stratification) were studied with logistic regression analysis in the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO)-I trial. The primary end point was 30-day death, which occurred in 6.3% of 10,348 patients randomly assigned to tissue plasminogen activator and 7.3% of 20,162 patients randomly assigned to streptokinase thrombolytic therapy. This is equivalent to an unadjusted odds ratio of 0.853. No significant imbalance had occurred for any of 17 baseline characteristics considered, including well-known demographic, presenting, and history characteristics. Adjusted for age, the odds ratio was 0.829, which is an 18% increase in estimated effect on the logistic scale. When adjusted for 17 characteristics, the odds ratio was 0.820, an increase of 25%. The increase in effect estimate was largely explained by the stratification effect and only partly by imbalance of predictors.

CONCLUSIONS

Adjustment for predictive baseline characteristics, even when largely balanced, may lead to clearly different estimates of the treatment effect on mortality rates. Adjustment for important predictors such as age is recommended in clinical trials studying patients with acute myocardial infarction.

Prognostic modelling with logistic regression analysis: a comparison of selection and estimation methods in small data sets

Logistic regression analysis may well be used to develop a prognostic model for a dichotomous outcome. Especially when limited data are available, it is difficult to determine an appropriate selection of covariables for inclusion in such models. Also, predictions may be improved by applying some sort of shrinkage in the estimation of regression coefficients. In this study we compare the performance of several selection and shrinkage methods in small data sets of patients with acute myocardial infarction, where we aim to predict 30-day mortality. Selection methods included backward stepwise selection with significance levels alpha of 0.01, 0.05, 0. 157 (the AIC criterion) or 0.50, and the use of qualitative external information on the sign of regression coefficients in the model. Estimation methods included standard maximum likelihood, the use of a linear shrinkage factor, penalized maximum likelihood, the Lasso, or quantitative external information on univariable regression coefficients. We found that stepwise selection with a low alpha (for example, 0.05) led to a relatively poor model performance, when evaluated on independent data. Substantially better performance was obtained with full models with a limited number of important predictors, where regression coefficients were reduced with any of the shrinkage methods. Incorporation of external information for selection and estimation improved the stability and quality of the prognostic models. We therefore recommend shrinkage methods in full models including prespecified predictors and incorporation of external information, when prognostic models are constructed in small data sets.

"Warm-up" phenomenon in adult and elderly patients with coronary artery disease: further evidence of the loss of "ischemic preconditioning" in the aging heart

BACKGROUND

A reduction of exercise-induced ischemia in patients with coronary artery disease by means of brief period of exercise followed by resting is called the "warm-up" phenomenon. This phenomenon may represent a clinical counterpart of "ischemic preconditioning." We studied the warm-up phenomenon in both adult and elderly patients with similar angiographic evidence of coronary artery disease, using three exercise tests after excluding the "training effect."

METHODS

In order to verify the presence of "training effect," three exercise tests were performed in days 1, 2, and 3 ("training" tests). The third test was used as baseline for a successive test, performed after a recovery period of 10 minutes to reestablish baseline electrocardiographic conditions. A third exercise test was performed 30 minutes later ("warm-up" tests).

RESULTS

"Training" tests did not differ in all parameters in both adult and elderly patients. "Warm-up" tests showed that time to onset 1-mm ST depression was significantly higher (p < .001). whereas ST depression and time to recovery was significantly lower in the second and third test in adult but not in elderly patients (p < .001 ). Difference (in seconds) in the time at which 1-mm ST depression occurred on first warm-up exercise compared with the second was inversely correlated with age (p < .001 ).

CONCLUSIONS

Previous exercise followed by resting is able to reduce the successive exercise-induced ischemia ("warm-up" phenomenon) in adult but not in elderly patients with coronary artery disease. This is independent of a greater age-related severity of coronary disease and of "training effect." These results confirm the hypothetical age-related reduction of "ischemic preconditioning" in aging heart.

Depressed mood and subjective health symptoms as predictors of mortality in patients with congestive heart failure: a two-years follow-up study

OBJECTIVE

The present study was undertaken in order to evaluate the relationship between depressed mood (depression, emotional distress) and disease-specific subjective health symptoms upon mortality risk among patients with congestive heart failure (CHF).

METHODS AND RESULTS

Proportional hazard models were used to evaluate the effects of selected biomedical, subjective health and psychological variables on mortality among 119 clinically stable patients (71.4% men; mean age 65.7 years +/- 9.6) with symptomatic heart failure, recruited from an outpatient cardiology practice. Twenty deaths were registered during the twenty-four-month period of data collection, all from cardiac causes. Results indicated that depressed mood was a significant predictor of mortality with a hazard ratio of 1.9, p .002. In contrast, subjective health was not a significant predictor of mortality in a Cox regression model that included depressed mood. The hazard ratio for a 1-point increase in Zung Depression Scale score was equal to 1.08 based on the multivariate model.

CONCLUSIONS

Results indicate that depressed mood is significantly related to increased mortality risk among heart failure patients. This finding is of concern to clinicians and should have implications for treatment of patients with congestive heart failure.

Prognostic models based on literature and individual patient data in logistic regression analysis

Prognostic models can be developed with multiple regression analysis of a data set containing individual patient data. Often this data set is relatively small, while previously published studies present results for larger numbers of patients. We describe a method to combine univariable regression results from the medical literature with univariable and multivariable results from the data set containing individual patient data. This 'adaptation method' exploits the generally strong correlation between univariable and multivariable regression coefficients. The method is illustrated with several logistic regression models to predict 30-day mortality in patients with acute myocardial infarction. The regression coefficients showed considerably less variability when estimated with the adaptation method, compared to standard maximum likelihood estimates. Also, model performance, as distinguished in calibration and discrimination, improved clearly when compared to models including shrunk or penalized estimates. We conclude that prognostic models may benefit substantially from explicit incorporation of literature data.

Very early assessment of risk for in-hospital death among 11,483 patients with acute myocardial infarction. GISSI investigators

BACKGROUND

The efficacy of reperfusion therapy after acute myocardial infarction is time dependent. The risk profile of every patient should be available as soon as possible. Our aim was to determine whether collection of simple clinical markers at hospital admission might allow reliable risk stratification for in-hospital mortality.

METHODS

The subjects were 11,483 patients with acute myocardial infarction from the GISSI-2 cohort. The GISSI-1 and GISSI-3 populations were selected to validate the classification. To stratify patients, the tree-growing method called recursive partitioning and amalgamation (RECPAM) was used. This method is used to identify homogeneous and distinct subgroups with respect to outcome.

RESULTS

The RECPAM algorithm provided 6 classes. RECPAM class I included Killip class 3 to class 4 patients (516 deaths/1000). RECPAM class II included Killip 2 patients older than 66 years and with anterior infarction or sites of infarction that could not be evaluated (314 deaths/1000). Killip 1 patients older than 75 years and with anterior or multiple sites or sites that could not be evaluated were included in RECPAM class III with Killip class 2 patients younger than 66 years and with systolic blood pressure less than 120 mm Hg or older than 66 years and with any other infarction site (207 deaths/1000). The other classes showed lower mortality rates (91, 32, and 12 deaths/1000 for RECPAM classes IV, V, and VI). In the GISSI 1 and GISSI 3 samples the 6 classes ranked in the same order in terms of mortality rate. With respect to low-risk strata, patients belonging to RECPAM class VI without serious clinical events in the first 4 days had a very low incidence of in-hospital death (0.9%) or morbidity. Cumulative 6-month mortality for the 6 RECPAM classes was 59.6%, 41.2%, 26.4%, 12.9%, 4. 8%, and 2.2%.

CONCLUSIONS

Four simple clinical markers readily available at admission of patients with myocardial infarction allow a quick, reliable, and inexpensive prediction of risk for in-hospital and 6-month mortality. The RECPAM classification also helped identify a large subgroup of patients fit for early hospital discharge.

Elderly patients at highest risk with acute myocardial infarction are more frequently transferred from community hospitals to tertiary centers: reality or myth?

BACKGROUND

The objective of this study was to assess the characteristics of patients with acute myocardial infarction transferred from community hospitals. The study was designed as a retrospective chart review, and the data source was the Cooperative Cardiovascular Project from Michigan.

METHODS AND RESULTS

Included in the study were consecutive Medicare patients with acute myocardial infarction discharged from acute-care hospitals in Michigan between April 1, 1994, and July 31, 1995 (n = 7041): 2866 patients treated at community hospitals, 1241 transferred from community hospitals, 2731 admitted directly to tertiary hospitals, and 203 transferred from an outside emergency room to tertiary hospitals. The outcomes measured were patient characteristics, quality indicators, resource use, and 30-day mortality rates. Compared with patients not transferred, those transferred from community hospitals were younger, more frequently of the male sex, smokers, and were seen earlier after symptom onset. They had fewer cases of diabetes and lower Acute Physiology And Chronic Health Evaluation (APACHE II) scores and Medicare Mortality Prediction System (MMPS) values. Aspirin during hospitalization and at discharge, thrombolytic therapy, and reperfusion therapy were all used more frequently in transferred patients, whereas the other key discharge quality indicators were no different. Mortality rate at 30 days was lower for transferred patients (9.4% vs 25%, P <.0001) when compared with those not transferred.

CONCLUSIONS

Patients who are less ill, those who are seen early, and those who received thrombolytic therapy are more often transferred from community hospitals. On average, patients with greater comorbidity rates are treated at community hospitals and not transferred. Predicted and observed mortality rates were lower for the transferred group. Higher comorbidity rate in patients treated at community hospitals appears to be the major determinant of the observed higher mortality rates in these patients.

Delayed thrombolytic treatment of older patients with acute myocardial infarction

OBJECTIVE

To determine demographic and clinical factors associated with delayed thrombolysis in patients with acute myocardial infarction.

DESIGN

A retrospective cohort.

SETTING

37 Minnesota hospitals during the time periods October 1992-July 1993 and July 1995-April 1996.

PATIENTS

We reviewed the medical records of 776 older patients aged 65 or older hospitalized with an admission diagnosis of acute myocardial infarction, suspected acute myocardial infarction, or rule-out acute myocardial infarction, who were treated with a thrombolytic agent.

MEASUREMENT

We used multivariate logistic regression models to examine the association between selected study characteristics and time between hospital presentation and administration of thrombolytic treatment. Early thrombolysis was defined as less than 60 minutes after hospital presentation and late thrombolysis as 60+ minutes.

RESULTS

Of 776 study patients, 57.5% (n = 446) received early thrombolysis. Of the remaining 330 patients receiving late treatment, 12.1% (n = 94) were thrombolyzed more than 2 hours after hospital presentation. After controlling for other factors, the odds of delayed thrombolysis among patients aged 75 or older were 1.48 compared with younger individuals (95% CI, 1.17-1.88). The odds of delayed thrombolysis among patients with severe comorbidity were 1.46 (95% CI, 1.10-1.94) compared with individuals without severe comorbidity. Predictors of early thrombolytic treatment included hospital arrival via emergency transport (ORdelay = 0.46; 95% CI, 0.34-0.63) and chest discomfort at admission (ORdelay = 0.40; 95% CI, 0.18-0.86).

CONCLUSIONS

The present study indicates that patients of advanced age and with severe comorbidity are more likely to experience delayed thrombolytic treatment after hospital presentation. These are the patients who suffer the highest morbidity from acute myocardial infarction and for whom expeditious treatment may enhance therapeutic benefit.

Sex-based differences in early mortality after myocardial infarction. National Registry of Myocardial Infarction 2 Participants

BACKGROUND

There is conflicting information about whether short-term mortality after myocardial infarction is higher among women than among men after adjustment for age and other prognostic factors. We hypothesized that younger, but not older, women have higher mortality rates during hospitalization than their male peers.

METHODS

We analyzed data on 384,878 patients (155,565 women and 229,313 men) who were 30 to 89 years of age and who had been enrolled in the National Registry of Myocardial Infarction 2 between June 1994 and January 1998. Patients who had been transferred from or to other hospitals were excluded.

RESULTS

The overall mortality rate during hospitalization was 16.7 percent among the women and 11.5 percent among the men. Sex-based differences in the rates varied according to age. Among patients less than 50 years of age, the mortality rate for the women was more than twice that for the men. The difference in the rates decreased with increasing age and was no longer significant after the age of 74 (P< 0.001 for the interaction between sex and age). Logistic-regression analysis showed that the odds of death were 11.1 percent greater for women than for men with every five-year decrease in age (95 percent confidence interval, 10.1 to 12.1 percent). Differences in medical history, the clinical severity of the infarction, and early management accounted for only about one third of the difference in the risk. After adjustment for these factors, women still had a higher risk of death for every five years of decreasing age (increase in the odds of death, 7.0 percent; 95 percent confidence interval, 5.9 to 8.1 percent).

CONCLUSIONS

After myocardial infarction, younger women, but not older women, have higher rates of death during hospitalization than men of the same age. The younger the age of the patients, the higher the risk of death among women relative to men. Younger women with myocardial infarction represent a high-risk group deserving of special study.

Long-term (three-year) prognosis of patients treated with reperfusion or conservatively after acute myocardial infarction. Israeli Thrombolytic Survey Group

OBJECTIVES

This survey sought to assess the frequency of the use of thrombolytic therapy, invasive coronary procedures (ICP) (angiography, percutaneous transluminal coronary angioplasty and coronary artery bypass grafting [CABG]), variables associated with their use, and their impact on early (30-day) and long-term (3-year) mortality after acute myocardial infarction (AMI).

BACKGROUND

Few data are available regarding the implementation in daily practice of the results of clinical trials of treatments for AMI and their impact on early and long-term prognosis in unselected patients after AMI.

METHODS

A prospective community-based national survey was conducted during January-February 1994 in all 25 coronary care units operating in Israel.

RESULTS

Among 999 consecutive patients with an AMI (72% men; mean age 63+/-12 years) acute reperfusion therapy (ART) was used in 455 patients (46%; thrombolysis in 435 patients [44%] and primary angioplasty in 20 [2%]). Its use was independently associated with anterior AMI location and hospitals with on-site angioplasty facilities, whereas advancing age, prior myocardial infarction (MI) and prior angioplasty or CABG were independently associated with its lower use. The three-year mortality of patients treated with ART was lower than in counterpart patients (22.0% vs. 31.4%, p = 0.0008), mainly as the result of 30-day to 3-year outcome (12.4% vs. 21.1%; hazard ratio = 0.73, 95% confidence interval [CI] 0.52 to 1.03). Independent predictors of long-term mortality were: age, heart failure on admission or during the hospitalization, ventricular tachycardia or fibrillation and diabetes. The outcome of patients not treated with ART differed according to the reason for the exclusion, where patients with contraindications experienced the highest three-year (50%) mortality rate. After ART, coronary angiography, angioplasty and CABG were performed in-hospital in 28%, 12% and 5% of patients, respectively. Their use was independently associated with recurrent infarction or ischemia, on-site catheterization or CABG facilities, non-Q-wave AMI and anterior infarct location. In the entire study population, and in patients with a non-Q-wave AMI, performance of ICP was associated with lower 30-day mortality (odds ratio [OR] = 0.53, 95% CI 0.25 to 0.98, and OR = 0.21, 0.03 to 0.84, respectively), but not thereafter.

CONCLUSIONS

This survey demonstrates the extent of implementation in daily practice of ART and ICP and their impact on early and long-term prognosis in an unselected population after AMI.