Myocardial infarction redefined--a consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction.

Definition of MI. Criteria for acute, evolving or recent MI. Either one of the following criteria satisfies the diagnosis for an acute, evolving or recent MI: 1) Typical rise and gradual fall (troponin) or more rapid rise and fall (CK-MB) of biochemical markers of myocardial necrosis with at least one of the following: a) ischemic symptoms; b) development of pathologic Qwaves on the ECG; c) ECG changes indicative of ischemia (ST segment elevation or depression); or d) coronary artery intervention (e.g., coronary angioplasty). 2) Pathologic findings of an acute MI. Criteria for established MI. Any one of the following criteria satisfies the diagnosis for established MI: 1) Development of new pathologic Q waves on serial ECGs. The patient may or may not remember previous symptoms. Biochemical markers of myocardial necrosis may have normalized, depending on the length of time that has passed since the infarct developed. 2) Pathologic findings of a healed or healing MI.

Accumulation of radioiodinated 15-(p-iodophenyl)-6-tellurapentadecanoic acid in ischemic myocardium during acute coronary occlusion and reperfusion.

The myocardial uptake of 15-(p-iodophenyl)-6- tellurapentadecanoic acid ( TPDA ) was studied in dogs during coronary occlusion and after reperfusion. In eight dogs with a 3 hour occlusion (Group A) with (n = 5) and without (n = 3) 30 minutes of reperfusion, iodine-125 TPDA uptake correlated well with microsphere myocardial blood flow over a wide range of flow levels (n = 111, r = 0.94). In six dogs with a 20 minute occlusion of the left anterior descending coronary artery and 1 hour of reperfusion (Group B), iodine-125 TPDA uptake correlated equally well with myocardial blood flow (n = 37, r = 0.90). There was no difference between the slopes of regression lines for Groups A and B, indicating no release from the myocardium of radioiodinated TPDA . Dual radiolabeling of TPDA was employed in five Group A animals by intravenous injection of iodine-125 TPDA during coronary occlusion and iodine-131 TPDA after reperfusion. In 63 myocardial samples, microsphere reperfusion flow and iodine-131 TPDA uptake were closely correlated (r = 0.91). As with monovalent cations, at myocardial flows higher than control flows, iodine-131 TPDA uptake was flow-limited. It is concluded that: 1) radioiodinated TPDA accurately reveals severely ischemic areas of myocardium without myocardial release of the radionuclide in coronary occlusions lasting 20 to 180 minutes and followed by reperfusion, and 2) double radiolabeled TPDA allows assessment of both occlusion and reperfusion flows. This compound may find an application in the measurement of infarct size and the evaluation of interventional therapies in acute myocardial infarction.

Myocardial infarction with angiographically normal coronary arteries.

More than 30 years ago, when the techniques and indications for coronary arteriography were being defined, the entity of myocardial infarction with angiographically normal coronary arteries (MINC) was first reported. These first reports already noted that the few patients with MINC tended to be different from the much larger group of individuals with myocardial necrosis and coronary atherosclerosis. Since these early case reports and subsequent small collected series, there have been significant advances in our understanding of the pathophysiologic features of acute myocardial infarction. This review seeks to reexamine MINC in light of this new information.

Diastolic function of the heart in clinical cardiology.

During the last six years, there has been increased interest in the detection of abnormalities of left ventricular diastolic function in patients with heart disease. Before 1981, most studies on diastolic function were performed in the catheter laboratory using invasive techniques and complex methods. Recently, radionuclide angiograms and Doppler echocardiography have been employed to measure the dynamics of filling in normal individuals and in patients with heart disease. These methods are noninvasive, easy to perform, accurate, and reproducible. It is now clear that diastolic function may be altered globally and regionally, at rest and perhaps during exercise, in many patients with ischemic heart disease, hypertension, and hypertrophic cardiomyopathy. Interestingly, these diastolic abnormalities may even appear before systolic abnormalities are identified in these patients. Thus, diastolic abnormalities may permit assessment of presence of disease early in its evolution. Whether detection and quantitation of diastolic abnormalities will permit grading of disease severity or evaluation of therapeutic efficacy remains an important research question. At the present time, it appears that the decision to employ either radionuclide angiography or Doppler echocardiography for the assessment of diastolic abnormalities will depend on the local expertise to carry out the investigation. Both diagnostic modalities require standardization of accuracy and reproducibility with proper selection of control values from the appropriate populations of normal individuals. It is also important to remember that left ventricular diastolic abnormalities have to be identified after the elimination of the confounding influence of variables such as ejection fraction, heart rate, age, and preload (end-diastolic volume). Automation of the derivation of indexes of diastolic filling should provide an objective assessment of the dynamics of left ventricular filling. Although the value of measurement of diastolic filling in the individual patient remains controversial, we believe that the practice of cardiology is incomplete without consideration of the second half of cardiac function.

The future of academic medical centers in the United States: passing through the valley of the shadow of death.

The last 2 decades witnessed remarkable events in the life of academic medical centers (AMCs) in the United States. Twenty years ago, AMCs were thriving as the era of fee-for-service medicine came to a close: clinical departments were expanding, hiring new faculty members, purchasing new equipment as necessary, and funding research projects and protected research time with the abundant clinical revenues. The subsequent 20 years since that golden era came to a close witnessed teh disappearance of these expansionary trends. Departments have contracted, protected research time and start-up funds have declined precipitously, and many faculty members are infected with a sense of malaise and fear for the future.

Multiple cholesterol emboli syndrome. Bowel infarction after retrograde angiography.

The two patients described in this article are among the first to have been diagnosed with extensive bowel infarction as a result of cholesterol embolization following cardiac catheterization. The presence of acute hypertension, renal insufficiency, livedo reticularis, and gangrenous skin changes are characteristic manifestations of the multiple cholesterol emboli syndrome. Additionally, gastrointestinal symptoms and melena may herald ischemia and infarction of the alimentary tract. Anticoagulation and thrombolytic therapy are relatively contraindicated in this syndrome and may, in fact, be a precipitating cause. The prognosis is usually poor; however, survival is possible with aggressive medical and surgical therapy, despite extensive infarction of the gastrointestinal tract and other organs. Prevention remains the most critical aspect of management of this potentially catastrophic illness.

The increased use of diagnostic procedures in patients with acute myocardial infarction. A community-wide perspective.

As part of a community-wide study examining time trends in the incidence and case-fatality rates of 3263 patients hospitalized with validated acute myocardial infarction (MI) during the years 1975, 1978, 1981, and 1984, we examined changes over time in the use of various noninvasive and invasive diagnostic tests during hospitalization for acute MI. In terms of the noninvasive procedures, exercise testing before hospital discharge increased from only 0.1% of patients in 1975 to 40.3% in 1984, while use of echocardiography (2.5%, 1975; 15.3%, 1984), Holter monitoring (1.0%, 1975; 34.0%, 1984), and radionuclide ventriculography (2.6%, 1975; 52.7%, 1984) also increased dramatically. Concerning the invasive procedures, use of coronary arteriography in patients with acute MI increased from 3.1% in 1975 to 9.8% in 1984. A more striking increase was noted in the use of pulmonary artery catheterization (7.2%, 1975; 19.9%, 1984). Examination of patient characteristics associated with the use of these tests demonstrated that the increased use of these diagnostic procedures was not due to changes in the clinical characteristics of patients hospitalized with acute MI; rather, it was the result of changes in physician practice patterns. If the practice patterns seen in this community-based study are similar to those seen throughout the United States, the charges for these diagnostic tests in 1984 are estimated to approach 600 million dollars. Given current interest in cost-containment and evaluation of clinical practices, these results suggest the need for further observational studies and clinical trials to assess the cost-effectiveness of these diagnostic tests. To assess the cost-effectiveness, it will be necessary to determine if the use of these tests improves the short-term or long-term prognosis of patients hospitalized with acute MI.

Does aspirin consumption affect the presentation or severity of acute myocardial infarction?

BACKGROUND: While consumption of aspirin has been shown to decrease the occurrence of nonfatal cardiac events, the majority of studies have not demonstrated any impact of aspirin intake on cardiovascular mortality. The present population-based study explores the possibility that aspirin consumption affects the presentation and severity of acute myocardial infarction (AMI), and hence the likelihood of clinical detection. METHODS: We monitored the use of aspirin before admission for 2114 patients with a validated diagnosis of AMI in 16 hospitals in the Worcester, Mass, metropolitan area during 1986, 1988, and 1990. The AMIs were characterized as Q wave vs non-Q wave and large (peak creatine kinase levels more than five times normal) vs small (peak creatine kinase levels less than two times normal). RESULTS: A total of 332 patients (16%) with validated AMI took aspirin before hospital admission. Nearly 65% of aspirin users had non-Q wave AMIs, compared with 49% of nonaspirin users. Thirty percent of aspirin users sustained small AMIs, compared with 22% of nonaspirin users. These findings persisted after stratifying for previous AMI, history of coronary disease, receipt of thrombolytic therapy, and exclusion of early hospital deaths. Using multivariable regression models to control for age, gender, previous evidence of coronary disease, and use of other medications, prior aspirin consumption remained independently associated with AMI type (non-Q-wave AMI) and smaller infarct size. CONCLUSION: Aspirin consumption appears to modify the presentation of AMI, increasing the likelihood that the infarct will be of the small, non-Q-wave variety.

Increasing frequency of staphylococcal infective endocarditis. Experience at a university hospital, 1981 through 1988.

To determine the characteristics of infective endocarditis in our hospital, we reviewed all patients with that diagnosis at the University of Massachusetts Medical Center, Worcester, between 1981 and 1988. Of 113 patients with infective endocarditis, 56 (50%) had staphylococcal endocarditis. Despite aggressive medical and surgical therapy, in-hospital mortality was 25%. Forty-five (80%) of the 56 cases of staphylococcal endocarditis involved Staphylococcus aureus with a mortality of 28% vs 9% in the non-S aureus group. Mortality was higher in patients with congestive heart failure (35%), atrioventricular block (45%), atrial fibrillation (42%), and prosthetic valve endocarditis (50%). Seventy-six percent of the patients with congestive heart failure required surgery. Patients with congestive heart failure and S aureus infection had a mortality of 45%. Thirty-six patients (64%) were alive at late follow-up (mean, 28.6 months). Mortality was highest (23%) during the first 3 months following diagnosis of staphylococcal endocarditis. Staphylococcal endocarditis represents an increasingly large proportion of patients with infectious endocarditis. Mortality rates remain high despite aggressive management of the patient's condition.

Recent trends in hospital mortality of acute myocardial infarction--the Worcester Heart Attack Study. Have improvements been realized for all age groups?

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Superior vena cava syndrome. Its association with indwelling balloon-tipped pulmonary artery catheters.

The placement of flow-directed pulmonary artery catheters has become a routine procedure in hospitals throughout the country. There have been scattered reports of complications associated with their placement, but in general, if it is done under proper conditions, it is associated with low morbidity and mortality. Recently, there have been questions raised regarding the thrombogenicity of these catheters. We report three cases of superior vena cava syndrome associated with the use of indwelling pulmonary artery catheters that we have encountered and a review of experience of others.

Gender differences in the treatment of patients with acute myocardial infarction. A multihospital, community-based perspective.

OBJECTIVE: As part of a community-wide study examining temporal trends in the incidence and survival rates of acute myocardial infarction, we examined differences between the sexes in overall utilization rates and changes over time, therein, of various therapies used in the management of acute myocardial infarction. DESIGN: Nonconcurrent prospective study. PATIENTS: Three thousand three hundred sixty-one men and 2119 women hospitalized with validated acute myocardial infarction in 16 hospitals in the Worcester, Mass, metropolitan area during 1975, 1978, 1981, 1984, 1986, 1988, and 1990. RESULTS: After controlling, by means of a logistic regression analysis, for a variety of patient-related factors that could affect physician prescribing patterns, women were significantly more likely to receive diuretics during hospitalization for acute myocardial infarction, whereas men were significantly more likely to receive antiplatelet agents, lidocaine, and other antiarrhythmic agents. No statistically significant differences were seen between men and women with regard to the use of anticoagulants, beta-blockers, calcium channel blockers, digoxin, nitrates, and thrombolytic agents. Marked increases over time (1975 through 1990) were seen in the use of anticoagulants, antiplatelet agents, beta-blockers, lidocaine, and nitrates in each of the sexes, while declines were seen in the use of digoxin and diuretics. Use of thrombolytic therapy increased between 1986 and 1990, whereas use of calcium channel blockers decreased over this period for both men and women. CONCLUSIONS: The results of this multihospital, population-based, observational study suggest that physician practice patterns in the pharmacologic treatment of men and women hospitalized with acute myocardial infarction are very similar.

Amino acid levels across normal forearm muscle and splanchnic bed after a protein meal.

To characterize further the role of blood cells in amino acid transport, four normal volunteers were asked to ingest 200 g of broiled ground sirloin within a 10-min period. Blood samples from a radial artery, a deep vein draining forearm muscle bed, and a tributary of the hepatic vein were obtained prior to and for 4 hr after the meal and analyzed for various hormones and substrates. At rest, analysis of arterio-deep venous differences across the forearm revealed the blood cell and plasma amino acid compartmentmental contents to be relatively constant except for alanine and glutamine. Whole blood arterio-hepatic venous (A-HV) amino acid differences were not significantly different from zero; however, blood cell A-HV difference analysis revealed a significant release of threonine from the splanchnic bed while plasma A-HV difference analysis revealed modest but significant releases of glutamate and ornithine and uptakes of phenylalanine and histidine. After the ingestion of the meat meal, plasma and blood cell levels of almost all of the measured amino acids increased significantly. Notable exceptions included glycine and alanine, levels of which did not change significantly and glutamine. The arterial blood cell content of the latter amino acid paradoxically decreased while arterial plasma levels increased significantly. Most importantly, large quantities of branched chain amino acids were released from the splanchnic bed and removed by forearm muscle. These data suggest that the blood cells of normal man do actively participate in amino acid transport, and that the magnitude and direction of change induced by the ingestion of a proteins meal varies with the individual amino acid.

Beta-blocker therapy in acute myocardial infarction: evidence for underutilization in the elderly.

PURPOSE: To assess the impact of patient age on the use of beta-blocker therapy in the management of acute myocardial infarction. PATIENTS AND METHODS: The population studied consisted of 4,762 patients hospitalized with validated acute myocardial infarction in 16 hospitals in the Worcester, Massachusetts, Standard Metropolitan Statistical Area during the years 1975, 1978, 1981, 1984, 1986, and 1988. Logistic regression analysis was employed to control for relevant demographic and clinical variables in evaluating the independent effect of patient age as a determinant of receipt of beta-blocker therapy during the hospitalization. RESULTS: A consistent trend toward reduced use of beta-blocker therapy in older patients was demonstrated. After adjustment for demographic and clinical variables (gender; prior history of angina, hypertension, or diabetes mellitus; myocardial infarction characteristics; complications including congestive heart failure and shock; and use of digoxin and diuretics), odds ratios for receipt of beta-blocker therapy relative to patients less than 55 years of age were 0.61 for those 55 to 64; 0.52 for those 65 to 74; 0.36 for those 75 to 84; and 0.26 for those 85 or older. Analyses performed for each study year demonstrated results consistent with those for the overall study population. CONCLUSION: The results of this population-based study suggest that there are substantial opportunities for expanded use of beta-blocker therapy in elderly patients who have sustained an acute myocardial infarction.

Multiple floppy valves: an echocardiographic syndrome.

Echocardiograms of 400 patients with mitral valve prolapse examined at the Peter Bent Brigham Hospital between 1974 and 1977 were reviewed. Eleven patients (3 per cent) were found to have prolapse (10 patients) or large excursion of the tricuspid valve (one patient) and large excursion of the aotric valve (four patients) or dilatation of the aotric root (seven patients) in addition to mitral valve prolapse. Two of these 11 patients underwent mitral valve replacement, and myxomatous degeneration of the valves was noted on pathologic examination. Almost half of the patients with multiple floppy valves (five of 11) had symptoms of congestive heart failure. In contrast to reported series of isolated mitral valve prolapse, in which female preponderance has been documented, 10 of the 11 patients were male. The syndrome of multiple floppy valves may represent either a unique entity or a more advanced form of the same process which underlies mitral valve prolapse.

Nitrate therapy in the elderly.

Changes in the heart and blood vessels with age alter the response of the cardiovascular system to pharmacologic agents. Nitrate plasma half-life is longer and volume of distribution is larger in older persons. Apparently, these pharmacokinetic differences in older persons lead to increased venous smooth muscle responsivity to nitrates which, in turn, leads to greater reductions in central venous and pulmonary arterial pressures after nitrate administration. This is probably the explanation for the greater frequency of nitrate-induced severe hypotension and bradycardia in elderly patients with myocardial infarction compared with younger patients. Clinicians should be cognizant of the changes in the cardiovascular system which occur with age that sensitize the elderly patient to the action of organic nitrates. Initial dosages of nitrates should accordingly be less than in younger patients.

Importance of the pharmacological profile of thrombolytic agents in clinical practice.

Three thrombolytic agents are frequently used in the United States for treating patients with acute myocardial infarction: streptokinase, alteplase (tissue plasminogen activator [t-PA]), and anistreplase (anisoylated plasminogen-streptokinase activator complex [APSAC]). A fourth agent, urokinase, is occasionally used but clinical experience is considerably more limited with this agent. Streptokinase, alteplase, and anistreplase differ in a number of pharmacologic properties, which include half-life, enzymatic efficiency, and induction of platelet aggregation; these differences may be clinically important. For example, anistreplase and alteplase have high affinity for fibrin and bind to intravascular thrombi after intravenous administration, which may result in higher clot specificity. Anistreplase has the longest half-life of the 3 agents and, therefore, can be administered conveniently and quickly. Alteplase has a shorter half-life and heparin is generally a necessary adjunctive agent. These differences can be clinically significant in various settings and application of such theoretical advantages is just beginning.

Is there a difference between a chief of cardiology and a chief of medicine?

The job of Chief of Medicine demands considerably more administrative effort than the Chief of Cardiology. However, one can still maintain a significant presence in cardiology as a Chief of Medicine. Each job has its own merits, joys, and irritations.

Myocardial scintigraphy with technetrium-99m pyrophosphate during the early phase of acute infarction.

To determine the sensitivity of myocardial scintigraphy with technetium-99m pyrophosphate during the early phase of acute myocardial infarction, 31 patients admitted to the coronary care unit with prolonged ischemic pain underwent imaging within 4 to 8 hours and again at 24 hours after the onset of symptoms. In 11 of 15 patients with documented acute myocardial infarction, increased focal myocardial uptake was demonstrated on early myocardial scintigraphy. Focal uptake was observed in only 2 of 16 patients with unstable angina pectoris. Three or four patients with normal early scintigrams had massive transmural myocardial infarction. Normal early scintigrams in these three patients may have reflected poor perfusion because the images were abnormal at 24 hours. In four patients the extent of technetium-99m pyrophosphate uptake increased more than 20 percent at 24 hours without other evidence of infarct extension. In the other seven patients, there was no significant change in the area of the abnormal radioactive uptake between early and delayed scintiscans. This study suggests that technetium-99m pyrophosphate scintigraphy can defect acute myocardial infarction as early as 4 hours after the onset of symptoms although the sensitivity rate (73 percent) is less than that at 24 hours.

Increased exercise tolerance and reduced duration of ischemia after isosorbide dinitrate oral spray in angina pectoris.

The prophylactic and therapeutic anti-ischemic efficacy of isosorbide dinitrate (ISDN) oral spray was assessed in 10 patients with coronary artery disease and stable angina pectoris. The patients entered a randomized crossover study of ISDN spray and placebo, involving bicycle exercise testing. Each patient underwent 2 exercise tests at least 4 hours apart. Immediately before initiation of exercise they received either ISDN spray or placebo and crossed over during the other test. ISDN spray delayed the onset of anginal pain by about 40%, from a mean of 5.1 +/- 1.4 minutes with placebo to 7.2 +/- 1.3 minutes with the active drug (p less than 0.001). Time of onset of ST-segment depression was also significantly prolonged, from 7.1 +/- 1.5 minutes with placebo to 10.2 +/- 1.2 minutes with ISDN (p less than 0.001). The patients achieved a higher double product at onset of pain with ISDN than with placebo. The drug also reduced the time of disappearance of pain after discontinuation of exercise from 3.2 +/- 0.7 to 2.1 +/- 0.8 minutes (p less than 0.001), and the time of disappearance of electrocardiographic changes from 4.2 +/- 0.6 to 2.5 +/- 0.8 minutes (p less than 0.005). These findings indicate that oral ISDN spray is an effective prophylactic for exercise-induced angina. Its rapid onset of action makes it especially suitable for usage immediately before exercise.