Myocardial Infarction In Older Patients Research Articles

Discontinuation of Antihyperglycemic Therapy and Clinical Outcomes After Acute Myocardial Infarction in Older Patients With Diabetes

Patients with diabetes are frequently admitted for acute myocardial infarction (AMI) on antihyperglycemic agents but may be discharged without glucose-lowering therapy. We examined the frequency of this practice and evaluated the associated outcomes of readmission and mortality. We conducted a retrospective study of 24 953 Medicare beneficiaries with diabetes discharged after hospitalization for AMI. We examined the frequency of discontinuation of antihyperglycemic agents on discharge among those patients admitted on a diabetic regimen. The independent association between discharge on versus off antihyperglycemic therapy and outcomes at 1 year was assessed in multivariable Cox proportional hazards models, adjusting for patient, physician, and hospital variables. The primary outcome was time to death within 1 year of discharge; secondary outcomes were time to first rehospitalization within 1 year for AMI, heart failure, and all causes. There were 8751 patients admitted on at least 1 antihyperglycemic agent who met our inclusion/exclusion criteria. Of these, 7581 (86.6%) were discharged on antihyperglycemic therapy and 1170 (13.4%) were discharged off antihyperglycemic therapy. After multivariable analysis, as compared with those whose diabetes therapy was continued at discharge, patients who were not prescribed a glucose-lowering agent had higher 1-year mortality rate (hazard ratio, 1.29; 95% confidence interval, 1.15 to 1.45). Readmission rates did not differ significantly between the 2 groups (hazard ratio, 0.95; 95% confidence interval, 0.87 to 1.03). In older patients with diabetes after AMI, discontinuation of antihyperglycemic therapy is common and associated with higher mortality rates. The reasons behind this practice as well as the specific effects of hyperglycemia after AMI merit further study.

Time trends in preventive drug treatment after myocardial infarction in older patients

Secondary preventive drug treatment in patients aged > or =60 years with a history of myocardial infarction was investigated for age-dependent differences in time trends. Sixteen general practices in the Netherlands participated. Preventive treatment with at least three of four drugs (antithrombotics, statins, beta-blockers, and/or angiotensin-converting enzyme inhibitors) increased significantly over time in all three age strata of older patients. Although the greatest relative increase (2.2 times greater) took place in patients aged > or =80 years, these patients consistently had most room for improvement.

Ambulatory ECG-Based T-Wave Alternans and Heart Rate Turbulence Predict High Risk of Arrhythmic Events in Patients With Old Myocardial Infarction

Few studies have explored risk stratification of arrhythmic events in patients with ischemic heart diseases according to T-wave alternans (TWA) using modified moving average (MMA) method and heart rate turbulence (HRT). A retrospective analysis of 63 patients who underwent MMA-based TWA and HRT divided the patients into 3 groups: group-C of 21 controls, group-O of 21 patients with old myocardial infarction (OMI) showing no episodes of sustained ventricular tachyarrhythmia (SVT), and group-V of 21 OMI patients with episodes of SVT who received an implantable cardioverter-defibrillator. Among the 3 groups, positive TWA (>or=65 microV) and impaired HRT were observed most frequently in group-V (P<0.05). Using a logistic regression model, TWA yielded an odds ratio of 4.9 (95% confidence interval: 1.2-19.6, P<0.05), which was the only significant covariate for the incidence of life-threatening ventricular arrhythmias during a mean follow-up of 72 months. Patients with OMI showing episodes of SVT have a high risk for cardiac death because of abnormal repolarization and autonomic regulation. The analysis of MMA-based TWA and HRT can be a useful tool for predicting OMI patients at high risk of arrhythmic events.

Safety and efficacy of intracoronary infusion of mobilized peripheral blood stem cell in patients with myocardial infarction: MAGIC Cell-1 and MAGIC Cell-3-DES-trials

Previous clinical studies evaluating granulocyte-colony stimulating factor (G-CSF)based stem-cell therapy showed inconsistent outcomes. We evaluated G-CSF-based stem-cell therapy in patients with acute myocardial infarction (AMI) and old myocardial infarction (OMI) in ‘Myocardial Regeneration and Angiogenesis in Myocardial Infarction with G-CSF and Intracoronary Stem Cell Infusion (MAGIC Cell)’ trials. In MAGIC Cell-1 trial, intracoronary infusion of mobilized stem cell by G-CSF is superior to G-CSF alone for improvement of left ventricular (LV) systolic function till 2 years follow-up. In MAGIC Cell-3-Drug eluting stent (DES) trial, cell infusion showed better improvement of LV systolic function and remodelling than control in AMI patients at 6 months follow-up. However, stem-cell therapy does not improve LV systolic function in OMI patients. G-CSF-based stem-cell therapy does not aggravate de novo progression of atherosclerosis while DES efficiently prevents G-CSF-based stem-cell-therapy-related restenosis. Longer-term follow-up is required to confirm prognostic impacts of stem-cell therapy in patients with myocardial infarction. Combination strategy with stem cell therapy with cytokines and genes should be introduced to enhance efficacy of current stem-cell therapy.

Differential Effect of Intracoronary Infusion of Mobilized Peripheral Blood Stem Cells by Granulocyte Colony–Stimulating Factor on Left Ventricular Function and Remodeling in Patients With Acute Myocardial Infarction Versus Old Myocardial Infarction

The efficacy of intracoronary infusion of granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood stem cells (PBSCs) has not been compared between patients with acute (AMI) versus old myocardial infarction (OMI). In addition, the potential risk of restenosis associated with G-CSF-based stem cell therapy has not been evaluated in the setting of drug eluting stent (DES) implantation. We randomly allocated 96 patients with myocardial infarction who underwent coronary revascularization with DES for the culprit lesion into 4 groups. Eighty-two patients completed 6-month follow-up; AMI cell infusion (n=25), AMI control (n=25), OMI cell infusion (n=16), and OMI control group (n=16). In cell infusion groups, PBSCs were mobilized by G-CSF for 3 days and delivered to infarcted myocardium via intracoronary infusion. The AMI cell infusion group showed a significant additive improvement in left ventricular ejection fraction (LVEF) and remodeling compared with controls (change of LVEF: +5.1+/-9.1% versus -0.2+/-8.6%, P<0.05; change of end-systolic volume: -5.4+/-17.0 mL versus 6.5+/-21.9 mL, P<0.05). In OMI patients, however, there was no significant change of LVEF and ventricular remodeling in spite of significant improvement of coronary flow reserve after cell infusion. G-CSF-based cell therapy did not aggravate neointimal growth with DES implantation. Intracoronary infusion of mobilized PBSCs with G-CSF improves LVEF and remodeling in patients with AMI but is less definite in patients with OMI. G-CSF-based stem cell therapy with DES implantation is both feasible and safe, eliminating any potential for restenosis.

Incidence of stroke after myocardial infarction

Incidence of stroke after myocardial infarction

Cardiac rehabilitation improved exercise tolerance after a myocardial infarction in older patients

Marchionni N, Fattirolli F, Fumagalli S, et al . Improved exercise tolerance and quality of life with cardiac rehabilitation of older patients after myocardial infarction: results of a randomized, controlled...

P2340 Homocysteine levels and prognosis after myocardial infarction in older patients

P2340 Homocysteine levels and prognosis after myocardial infarction in older patients

Usefulness of magnetic resonance imaging in diagnosis of arrhythmogenic right ventricular dysplasia and agreement with electrocardiographic criteria

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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.

Recovery time dispersion measured by body surface mapping: Noninvasive method of assessing vulnerability to ventricular tachyarrhythmias

To assess the significance of recovery time (RT) dispersion measured by body surface mapping, we investigated body surface RT isochrone maps of 40 patients with anterior old myocardial infarction (OMI), 40 patients with dilated cardiomyopathy (DCM), and 40 controls. Among the OMI and DCM groups, 20 patients per group had sustained ventricular tachycardia (VT). The dispersion of corrected recovery time (RTc) by Bazett's formula significantly increased in OMI patients (169 ± 38 ms) and DCM patients (163 ± 22 ms) compared with controls (147 ± 10 ms) ( P < .01). RTc dispersion was greater in OMI patients with sustained VT than in those without sustained VT [184 ± 43 ms vs. 155 ± 24 ms ( P < .05)], as well as in DCM patients with sustained VT compared with those without sustained VT [170 ± 25 ms vs. 156 ± 17 ms ( P < .05)]. The results suggest that RTc dispersion determined by body surface mapping can be useful for assessing vulnerability to sustained VT.

Prognostic value of dipyridamole thallium imaging after acute myocardial infarction in older patients.

To assess the utility of intravenous dipyridamole thallium testing for predicting major cardiac events following acute myocardial infarction in older patients. Prospective cohort study with a median follow-up of 18 months. A university teaching hospital. 73 patients aged 65 years and older with enzymatically confirmed acute myocardial infarction (mean age 75 years, 56% male, 71% white). All patients underwent a detailed clinical assessment, an echocardiogram, and an intravenous dipyridamole thallium stress test before hospital discharge. The study endpoint was death or nonfatal reinfarction during the follow-up period. Overall, 24 patients (33%) died or developed recurrent myocardial infarction during follow-up. Among 44 patients with a reversible thallium defect, 19 (43%) reached the study endpoint, compared with only five of 29 patients (17%) without reversible ischemia (P = .04). On multivariate analysis, independent prognostic variables included non-use of aspirin at hospital discharge (P = .002), decreased left ventricular systolic function (P = .009), non-use of a beta-blocker at hospital discharge (P = .013), and reversible ischemia on thallium scintigraphy (P = .025). The relative risks for death or reinfarction associated with non-use of aspirin, non-use of a beta-blocker, left ventricular dysfunction, and reversible ischemia were 2.65, 2.39, 2.01, and 2.51, respectively. Patients with three or four of these risk factors had an 83% probability of death or reinfarction, compared with 41% in patients with two risk factors and 6% in patients with one or no risk factor (P < .001). Intravenous dipyridamole thallium imaging provides independent prognostic information in older patients with acute myocardial infarction. Moreover, the combination of clinical, echocardiographic, and dipyridamole thallium variables effectively stratifies older postinfarction patients into high-, intermediate-, and low-risk categories for death or recurrent myocardial infarction.

Management and outcome of acute myocardial infarction in older patients in the thrombolytic era.

Acute myocardial infarction (AMI) is an important cause of mortality and morbidity in older patients. The aim of this study was to determine the proportion of unselected admissions with AMI that is older than 75 years and to examine management and outcomes in this group. An historical cohort study of consecutive unselected admissions with AMI identified using the Hospital In Patient Enquiry (HIPE) database and validated according to MONICA criteria for definite or probable AMI. An acute cardiac unit in a university teaching hospital/cardiac tertiary referral center. Of 1059 patients, 606 (57%) were older than 65 years and 309 (29.2%) were older than 75 years. Mean age in this group was 80.5 years. Hospital mortality was almost twice as high as in patients younger than 75 years (28% vs 15%, P < .001), and age was an independent predictor of short- and long-term mortality following AMI. Women constituted a significantly higher proportion of older patients. Family history of AMI and cigarette smoking were less prevalent in older patients. Mean cholesterol was lower and comorbidities were higher. Other baseline characteristics, including previous AMI, did not differ. However older patients were less likely to receive thrombolysis (13% vs 36%, P < .001), aspirin (76% vs 86%, P < .01), or beta-blockers (25% vs 51%, P < .001) and were less likely to undergo cardiac catheterization or revascularization. Only 53% were admitted to coronary care. Patients more than age 75 comprise almost one-third of patients with AMI and have a poor prognosis. Although age is an independent predictor of mortality following AMI, suboptimal management may contribute to the high mortality in these patients.

Recent Trends in Hospital Mortality of Acute Myocardial Infarction—the Worcester Heart Attack Study

While age-related differences in patterns of care for acute myocardial infarction have been demonstrated, temporal trends in clinical outcome for patients in different age groups have not been carefully examined. We analyzed data collected as part of an ongoing communitywide study of 5480 patients hospitalized with validated acute myocardial infarction in Worcester, Mass, during 7 selected years spanning a 15-year period (1975 through 1990). Patients were stratified into three age groups: less than 65 years (n = 2220), 65 through 74 years (n = 1595), and 75 years or older (n = 1665). Within each age group, the odds of in-hospital death were determined by study year, with adjustments for selected demographic, clinical, and hospital characteristics. For patients less than age 65 years, the odds of dying during the acute hospital phase of myocardial infarction were reduced for all study years relative to the reference year (1975), reaching their lowest level in 1990 (adjusted odds ratio [OR], 0.16; 95% confidence interval [CI], 0.06 to 0.48). For patients aged 65 through 74 years, the odds of dying declined among patients hospitalized in 1978 (adjusted OR, 0.71; 95% CI, 0.39 to 1.29) and 1981 (adjusted OR, 0.36; 95% CI, 0.19 to 0.66) but remained essentially unchanged during the subsequent study years through 1990. For patients 75 years of age or older, the odds of dying declined through 1984 (adjusted OR, 0.42; 95% CI, 0.25 to 0.72) but increased over the following study years: 1986, 1988, and 1990. While the risk of in-hospital death following acute myocardial infarction has recently declined for patients less than 65 years of age, improvements have not been realized for older age groups. Current patterns of management of acute myocardial infarction in older patients require reexamination.

Cost effectiveness of thrombolytic therapy with streptokinase in elderly patients with suspected acute myocardial infarction.

There is a lack of consensus among cardiologists about the potential benefit of thrombolytic therapy for suspected acute myocardial infarction in older patients. To investigate this issue, we constructed a decision-analytic model for patients 75 years of age or older who present with ST-segment elevation within six hours of the onset of symptoms suggesting acute myocardial infarction. The variables incorporated in this model were the probability that the patient has an acute myocardial infarction, the probability of in-hospital death among patients with acute myocardial infarction who do not receive thrombolytic therapy, the probability of a fatal or incapacitating complication resulting from thrombolytic therapy, and the expected relative reduction in the risk of death associated with thrombolytic therapy in patients with acute myocardial infarction. Our analyses were based primarily on the use of streptokinase as the thrombolytic agent. Given our base-line assumptions, the probability of dying in the hospital was 21.4 percent if thrombolytic therapy was given and 24.4 percent if it was not given. In one-way sensitivity analyses, thrombolytic therapy decreased the risk of dying if the probability that the patient had an acute myocardial infarction was assumed to be greater than 9 percent, if the probability of dying in the hospital after an acute myocardial infarction without thrombolytic therapy was assumed to be greater than 3 percent, if the rate of fatal or incapacitating complications due to thrombolytic therapy was assumed to be 4 percent or less, or if the relative reduction in the risk of death associated with thrombolytic therapy was assumed to be greater than 1 percent. On the basis of our base-line assumptions, our estimate of the cost effectiveness of streptokinase therapy (the cost per year of life saved) for an 80-year-old patient with suspected acute myocardial infarction was $21,200. For a wide range of assumptions about risks, benefits, and costs, the cost per year of life saved remained less than $55,000. Within the limitations imposed by the assumptions used in our analysis, thrombolytic therapy with streptokinase was found to be a beneficial and cost-effective treatment for suspected acute myocardial infarction in elderly patients in a wide variety of clinical circumstances.