Troponin T as a marker for myocardial ischemia in patients undergoing major noncardiac surgery

To assess the diagnostic performance of cardiac troponin T as a marker for myocardial injury in patients undergoing major noncardiac surgery, we prospectively collected preoperative and postoperative clinical data, including measurements for creatine kinase (CK), CK-MB, and troponin T for 1,175 patients undergoing major noncardiac surgery. Acute myocardial infarction was diagnosed in 17 patients (1.4%) by a reviewer who was blinded to troponin T data and who used CK-MB and electrocardiographic criteria to define acute myocardial infarction. Other predischarge major cardiac complications were detected for another 17 patients. Troponin T elevations (>0.1 ng/ml) occurred in 87% of patients with and in 16% of patients without myocardial infarction. Among patients without myocardial infarction, troponin T was elevated in 62% of patients with and in 15% of patients without major cardiac complications. Receiver-operating characteristic analysis indicated that troponin T had a performance for the diagnosis of acute myocardial infarction similar to CK-MB, and a significantly better correlation with other major cardiac complications in patients without definitive infarction. Future research should seek to determine the significance of troponin T elevations in patients without complications.     

Treatment of subacute cardiac rupture after myocardial infarction

Five successfully treated cases of subacute cardiac rupture after myocardial infarction are described. There were 4 men and 1 woman, ranging in age from 51 to 71 years. Two patients had systemic hypertension. Rupture occurred during the first myocardial infarction in all patients. The interval from the onset of myocardial infarction to cardiac rupture ranged from 1 to 6 days (mean 4 days). In one patient, the rupture was repaired under cardiopulmonary bypass using an autologous pericardial patch over the infarcted myocardium. Two patients underwent sutureless repair with fibrin glue; one of them developed a left ventricular pseudoaneurysm 2 years after the operation, requiring resection. These three patients were operated on through a median sternotomy. The remaining two patients were treated for cardiac tamponade by pericardial drainage through a subxiphoid incision; one died 38 days after the operation due to congestive heart failure. The four surviving patients are currently well 22, 39, 41 and 60 months after surgery. In summary, a conservative approach may be effective for treatment of subacute cardiac rupture.     

Long-term beneficial effect of late reperfusion for acute anterior myocardial infarction with percutaneous transluminal coronary angioplasty

BACKGROUND: Although the short-term and long-term beneficial effects of early coronary revascularization by primary PTCA or thrombolytic therapy have been established for acute myocardial infarction, thrombolytic therapy >24 hours after the onset of acute myocardial infarction has not been shown to improve clinical outcome. The purpose of this study was to assess the effect of late revascularization by primary PTCA over a 5-year period. METHODS AND RESULTS: Eighty-three patients with initial Q-wave anterior myocardial infarction >24 hours after onset were randomized into a PTCA group (n=44) and a no-PTCA group (n=39). Long-term follow-up was conducted with regard to end points, which included cardiac death, nonfatal recurrence of myocardial infarction, and development of congestive heart failure. Left ventricular ejection fraction and regional wall motion at 6 months after myocardial infarction were similar in the 2 groups. Left ventricular end-diastolic and end-systolic volume indexes were significantly smaller in the PTCA group than in the no-PTCA group (P<0.0001). With cardiac events as end points, a 5-year Kaplan-Meier event-free survival analysis revealed that the no-PTCA group had a worse prognosis than the PTCA group (P<0.0001). Patency of the infarct-related artery, left ventricular ejection fraction, end-diastolic volume index, and end-systolic volume index were significantly associated with cardiac events by a Cox proportional hazards analysis (hazard ratios 0.120, 0.845, 1.065, and 1.164, respectively). CONCLUSIONS: In initial Q-wave anterior myocardial infarction, we conclude that even with late reperfusion, PTCA had beneficial effects on cardiac events over the 5-year period after myocardial infarction, with the prevention of left ventricular dilation after myocardial infarction being a possible mechanism.     

Chain elongation in the isoprenoid biosynthetic pathway

PURPOSE: To investigate the associations between specific preoperative 12-lead electrocardiogram (ECG) abnormalities, perioperative ischemia, and postoperative myocardial infarction or cardiac death in major vascular surgery. METHODS: Two prospective studies on perioperative myocardial ischemia performed in two tertiary university hospitals were combined to include 405 patients. All preoperative ECGs were analyzed according to the Sokolow-Lyon criteria for left ventricular hypertrophy by investigators who were blinded to the patients' perioperative clinical course. Perioperative myocardial ischemia was detected by continuous ECG recording, and postoperative cardiac complications included myocardial infarction and cardiac death. RESULTS: A total of 19 postoperative cardiac complications occurred (two cardiac deaths and 17 myocardial infarctions). Voltage criteria for left ventricular hypertrophy (78 patients, 19%) and ST segment depression greater than 0.5 mm (98 patients, 24.2%) on preoperative ECGs were both significantly associated with postoperative myocardial infarction or cardiac death (odds ratio, 4.2 and 4.7; p = 0.001 and 0.0005, respectively) and with longer intraoperative and postoperative myocardial ischemia. In each of the two study groups, a preoperative ECG abnormality that involved voltage criteria, ST segment depression, or both (134 patients, 33.1%) was more predictive of postoperative cardiac complications than any other preoperative clinical variable, including a history of myocardial infarction or angina pectoris, diabetes mellitus, pathologic Q-wave by ECG, or preoperative myocardial ischemia. The combined duration of intraoperative and postoperative ischemia and the preoperative ECG with either voltage criteria or ST segment depression were the only independent factors associated with adverse cardiac events by multivariate analysis (p < or = 0.0001 and p = 0.02, respectively). CONCLUSION: Left ventricular hypertrophy and ST segment depression on preoperative 12-lead ECGs are important markers of increased risk for myocardial infarction or cardiac death after major vascular surgery.     

C-reactive protein as a predictor of cardiac rupture after acute myocardial infarction

Although cardiac rupture is the second most common cause of death after ventricular failure in acute myocardial infarction, no diagnosis has ever been made before an episode of clinical compromise, and no significant predictive factors have been described. This study was designed to determine whether high serum C-reactive protein (CRP) levels could predict the incidence of subacute cardiac rupture after acute myocardial infarction. Nine consecutive patients with cardiac rupture were compared retrospectively with 28 consecutive control patients without rupture after acute myocardial infarction. In the rupture group, peak serum CRP levels increased rapidly and markedly after infarction, reaching more than 20 mg/dl on day 2, and persisted at high levels compared with those in the control group. However, the time course and levels of serum creatine phosphokinase were not significantly different between the two groups. High serum CRP levels ( > 20 mg/dl) had a high diagnostic sensitivity (89%) and specificity (96%) for cardiac rupture. Patients with persistently high serum CRP levels, particularly above 20 mg/dl, might have high probability of occurrence of sub-acute cardiac rupture after acute myocardial infarction.     

Poor long-term survival after acute myocardial infarction among patients on long-term dialysis

BACKGROUND: Cardiovascular disease is common in patients on long-term dialysis, and it accounts for 44 percent of overall mortality in this group. We undertook a study to assess long-term survival after acute myocardial infarction among patients in the United States who were receiving long-term dialysis. METHODS: Patients on dialysis who were hospitalized during the period from 1977 to 1995 for a first myocardial infarction after the initiation of renal-replacement therapy were retrospectively identified from the U.S. Renal Data System data base. Overall mortality and mortality from cardiac causes (including all in-hospital deaths) were estimated by the life-table method. The effect of independent predictors on survival was examined in a Cox regression model with adjustment for existing illnesses. RESULTS: The overall mortality (+/-SE) after acute myocardial infarction among 34,189 patients on long-term dialysis was 59.3+/-0.3 percent at one year, 73.0+/-0.3 percent at two years, and 89.9+/-0.2 percent at five years. The mortality from cardiac causes was 40.8+/-0.3 percent at one year, 51.8+/-0.3 percent at two years, and 70.2+/-0.4 percent at five years. Patients who were older or had diabetes had higher mortality than patients without these characteristics. Adverse outcomes occurred even in patients who had acute myocardial infarction in 1990 through 1995. Also, the mortality rate after myocardial infarction was considerably higher for patients on long-term dialysis than for renal-transplant recipients. CONCLUSIONS: Patients on dialysis who have acute myocardial infarction have high mortality from cardiac causes and poor long-term survival.     

Observations of the treatment of women in the United States with myocardial infarction: a report from the National Registry of Myocardial Infarction-I

BACKGROUND: To determine whether there are sex differences in the demographics, treatment, and outcome of patients with acute myocardial infarction in the United States, data from the National Registry of Myocardial Infarction-I from September 1990 to September 1994 were examined. METHODS: The National Registry of Myocardial Infarction-I is a national observational database consisting of 1234 US hospitals in which each hospital submits data from each patient with acute myocardial infarction to a central data collection center. For these analyses, the following variables were examined in 354 435 patients with acute myocardial infarction: demographics; use of medical therapy including thrombolytic agents; use of procedures including cardiac catheterization, percutaneous transluminal coronary angioplasty, and coronary artery bypass surgery; length of hospital stay; adverse events (stroke, major bleeding, or recurrent myocardial infarction); and causes of death. RESULTS: In comparison with men, women experiencing acute myocardial infarction in the United States are older, with 55.7% older than 70 years. Women have a higher mortality rate than men even when controlled for age and die less often from arrhythmia but more often from cardiac rupture whether or not thrombolytic therapy is used. Treatment with aspirin, heparin, or beta-blockers is less frequent in women. When thrombolytic therapy is used, women are treated an average of almost 14 minutes later than men and experience a greater incidence of major bleeding. Cardiac catheterization, percutaneous transluminal coronary angioplasty, and coronary artery bypass surgery are used less often in women. CONCLUSIONS: Observations from the National Registry of Myocardial Infarction-I document important sex differences in demographics, treatment, and outcome of patients with acute myocardial infarction in the United States.     

Acute myocardial infarction related to cocaine use. Report of a case

Cocaine use has been associated with ischemic syndromes, especially angor pectoris, myocardial infarction, cardiac arrhythmias and sudden death. A significant number of persons suffering from myocardial infarction associated with cocaine abuse do not have significant coronary atherosclerosis, and the mechanism for infarction in these patients have remained obscure. This report describes a young man with angiographically normal coronary arteries in whom cocaine abuse probably produced coronary artery spasm leading to coronary thrombosis and infarction.     

Regional variation across the United States in the management of acute myocardial infarction. GUSTO-1 Investigators. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries

BACKGROUND: Differences in the management of acute myocardial infarction have been reported among countries, but few studies have investigated this issue in regions of the United States. METHODS: We compared the management of acute myocardial infarction among census regions across the United States, using data from the first Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries trial (GUSTO-1) comprising 21,772 patients, and from the American Hospital Association. RESULTS: We found substantial regional variation in the management of acute myocardial infarction in the United States. Beta-blockers (prescribed for a range of 55 to 81 percent of patients in the various regions), nitrates (prescribed for 61 to 77 percent), and angiotensin-converting-enzyme inhibitors (prescribed for 18 to 23 percent) were used most often in New England, whereas calcium-channel blockers (31 to 42 percent) and lidocaine (14 to 43 percent) were used least often there. Similarly, the proportion of patients undergoing various cardiac procedures differed among regions (range for angiography, 52 to 81 percent of patients; angioplasty, 22 to 35 percent; and coronary-artery bypass surgery, 9 to 17 percent) and was lowest in New England. The regional use of cardiac procedures was closely related to their availability, except in New England. After the analysis was adjusted for clinical and hospital variables, patients in New England were found to be less likely to undergo angiography than patients in the other regions (odds ratio, 0.37; 95 percent confidence interval, 0.32 to 0.42). There was no apparent relation between the use of cardiac procedures and rates of recurrent infarction or death at 30 days or 1 year. CONCLUSIONS: There is substantial regional variation in the use of cardiac medications and procedures to manage acute myocardial infarction in the United States. The use and availability of cardiac procedures are closely related. The management of acute myocardial infarction in New England is atypical in that the relatively limited availability of cardiac procedures does not account for their relatively low use in that region.     

Arrhythmias associated with acute myocardial infarction and thrombolysis

Ninety percent of patients with acute myocardial infarction have some cardiac rhythm abnormality, and approximately twenty-five percent have cardiac conduction disturbance within 24 hours following infarct onset. Almost any rhythm disturbance can be associated with acute myocardial infarction, including bradyarrhythmias, supraventricular tachyarrhythmias, ventricular arrhythmias, and atrioventricular block. With the advent of thrombolytic therapy, it was found that some rhythm disturbances in patients with acute myocardial infarction may be related to successful coronary artery reperfusion. This article addresses the role and treatment of arrhythmias and conduction disturbances that complicate the course of patients with acute infarction and thrombolysis.     

Diagnosis of perioperative myocardial infarction by cardiac troponin T following coronary artery bypass grafting

The determinations of cardiac troponin T provide the highest diagnostic efficiency for the detection of myocardial cell necrosis. To assess perioperative myocardial infarction, serum levels of cardiac troponin T were determined in 14 patients undergoing coronary artery bypass grafting (CABG). The patients were divided into two groups: group I (n = 9), those whose troponin T was less than 1.00 ng/ml on the first postoperative day; group II (n = 5), those whose troponin T was more than 1.00 ng/ml on the first postoperative day. Troponin T levels in group II patients were significantly higher than in group I from the second to the seventh postoperative day. Two patients in group II had specific changes on the electrocardiogram detecting perioperative myocardial infarction as a new Q wave and R wave reduction. These results suggest that troponin T is a valuable marker of perioperative myocardial infarction following CABG.     

The differing prognostic utility of exercise radionuclide ventriculography in coronary artery disease patients with and without prior myocardial infarction

Previous studies have documented the prognostic utility of left ventricular ejection fraction response to exercise primarily in populations without prior myocardial infarction. We undertook a study to assess the prognostic utility of exercise left ventricular ejection fraction and segmental wall motion response during exercise radionuclide ventriculography in coronary artery disease patients with and without prior myocardial infarction. METHODS: We examined the comparative prognostic utility of left ventricular ejection fraction and segmental wall motion response during upright bicycle exercise radionuclide ventriculography in 419 coronary artery disease patients with (n = 217) and without (n = 202) prior myocardial infarction using univariate and multivariate hierarchical regression analyses. RESULTS: During an average followup period of 61 months, 96 patients (23%) suffered cardiac events, including 55/217 (25%) of the patients with prior myocardial infarction and 41/200 (21%) of the patients without prior myocardial infarction (p = ns). Both cumulative Kaplan-Meier survival analyses and stepwise hierarchical Cox survival analyses demonstrated that peak left ventricular ejection fraction < 55% was a significant predictor of cardiac events in patients without prior myocardial infarction (p = 0.04), whereas an exercise wall motion worsening score > or = 2 was a significant predictor in patients with a prior myocardial infarction (p = 0.0001). CONCLUSIONS: The prognostic utility of exercise radionuclide ventriculography variables differ according to the presence or absence of prior myocardial infarction. Global function, assessed by peak left ventricular ejection fraction, adds the greatest prognostic information in patients without prior myocardial infarction, whereas regional function, assessed by exercise wall motion worsening, is the best predictor among patients with prior myocardial infarction.     

Contraction of experimental skin flaps

BACKGROUND AND PURPOSE: Some types of radiation therapy have been associated with an increased risk of cardiac mortality and morbidity in patients with early-stage breast cancer. A relationship has been observed between cardiac radiation dose-volume and the level of excess risk of cardiac mortality. However, relatively few data are available on the morbidity from myocardial infarction associated with adjuvant radiotherapy. PATIENTS AND METHODS: From 1971 to 1976, a total of 960 patients with operable breast cancer were randomly allocated to preoperative radiation therapy, postoperative radiation therapy or to surgery alone. A previous analysis of the cardiac dose-volumes with the treatment techniques used in the trial indicated that the irradiated patients could roughly be divided into three groups. Information on the number of myocardial infarctions was obtained through computerized record linkage with a population-based registry of myocardial infarctions in Stockholm County. Information on cause-specific mortality was obtained from the Swedish Cause-of-Death Registry. The median follow-up was 20 years (range 17-23 years). RESULTS: A total of 58 patients developed an acute myocardial infarction during the period of follow-up. The number of myocardial infarction cases was not significantly different between the three treatment groups. When analyzed according to estimated cardiac radiation dose-volumes, patients in the highest dose-volume subgroup exhibited a hazard of myocardial infarction of 1.3 (95% CI 0.7-2.6) relative to that of the surgical controls, whereas the corresponding relative hazard for the intermediate and low dose-volume subgroups was below unity. Data on death due to cardiovascular disease showed that patients in the high dose-volume group exhibited a hazard of 2.0 (95% CI 1.0-3.9, P = 0.04) relative to that of the surgical controls. Concerning death due to ischemic heart disease, the relative hazard for the same subgroup was 2.5 (95% CI 1.1-5.7, P = 0.03). The difference between the groups was established after 4-5 years. The cumulative incidence curves continued to diverge up to about 10-12 years. No further divergence appeared after 12 years, but the number of events was low. CONCLUSIONS: This analysis confirms and extends previous results from the trial. Cardiac mortality was positively correlated with the cardiac dose-volume. Patients receiving high dose-volumes exhibited an increased mortality of ischemic heart disease, but not of myocardial infarction, which implies another mechanism, e.g. radiation-induced microvascular damage to the heart.     

Projected cost-effectiveness of primary angioplasty for acute myocardial infarction

OBJECTIVES: This study sought to evaluate the cost-effectiveness of primary angioplasty for acute myocardial infarction under varying assumptions about effectiveness, existing facilities and staffing and volume of services. BACKGROUND: Primary angioplasty for acute myocardial infarction has reduced mortality in some studies, but its actual effectiveness may vary, and most U.S. hospitals do not have cardiac catheterization laboratories. Projections of cost-effectiveness in various settings are needed for decisions about adoption. METHODS: We created a decision analytic model to compare three policies: primary angioplasty, intravenous thrombolysis and no intervention. Probabilities of health outcomes were taken from randomized trials (base case efficacy assumptions) and community-based studies (effectiveness assumptions). The base case analysis assumed that a hospital with an existing laboratory with night/weekend staffing coverage admitted 200 patients with a myocardial infarction annually. In alternative scenarios, a new laboratory was built, and its capacity for elective procedures was either 1) needed or 2) redundant with existing laboratories. RESULTS: Under base case efficacy assumptions, primary angioplasty resulted in cost savings compared with thrombolysis and had a cost of $12,000/quality-adjusted life-year (QALY) saved compared with no intervention. In sensitivity analyses, when there was an existing cardiac catheterization laboratory at a hospital with > or = 200 patients with a myocardial infarction annually, primary angioplasty had a cost of < $30,000/QALY saved under a wide range of assumptions. However, the cost/QALY saved increased sharply under effectiveness assumptions when the hospital had < 150 patients with a myocardial infarction annually or when a redundant laboratory was built. CONCLUSIONS: At hospitals with an existing cardiac catheterization laboratory, primary angioplasty for acute myocardial infarction would be cost-effective relative to other medical interventions under a wide range of assumptions. The procedure's relative cost-ineffectiveness at low volumes or redundant laboratories supports regionalization of cardiac services in urban areas. However, approaches to overcoming competitive barriers and close monitoring of outcomes and costs will be needed.     

Autonomic nervous system activity in essential hypertension: a comparison between dippers and non-dippers

This study examines whether race is a significant determinant of the diagnoses of acute myocardial infarction or angina pectoris in patients with symptoms suggestive of acute cardiac ischemia. The study population was comprised of 3401 (34%) African-American and 6600 (66%) white patients who presented to emergency departments with symptoms suggestive of acute cardiac ischemia. The main outcome measure was a diagnosis of acute myocardial infarction or angina pectoris. African Americans were younger, predominantly female, and more often had hypertension, diabetes mellitus, or smoked. The diagnosis of acute myocardial infarction was confirmed in 6% of African-American and 12% of white men, and in 4% of African-American and 8% of white women. After adjusting for age, gender, medical history, signs and symptoms, and hospital, African Americans were half as likely to develop acute myocardial infarction and were 60% as likely to have acute cardiac ischemia. Despite having less acute cardiac ischemia, African Americans in this study had high risk levels for coronary artery disease.     

Comparison of angiotensin converting enzyme and renin inhibition in rats following myocardial infarction

Renal and systemic hemodynamics were studied in rats 1 month after induction of myocardial infarction by ligation of the left coronary artery. The mean arterial pressure, heart rate, and cardiac index were not different from controls, but there were striking elevations in heart weight (p < 0.001), left ventricular end diastolic pressure (p < 0.002), and renal vascular resistance (p < 0.01). Renal blood flow and the percent of cardiac output perfusing the kidneys were reduced by 18% (p < 0.01) and 14% (p < 0.01), respectively. Acute angiotensin inhibition was studied at a dose of the converting enzyme inhibitor, enalapril, or the renin inhibitor, CP71362, that lowered the mean arterial pressure by 15 mm Hg in normal rats. In normal rats, enalapril and CP71362 were without effect on renal blood flow (RBF), renal vascular resistance (RR), and RBF as a percent of cardiac output. However, in rats with myocardial infarction, enalapril and CP71362 increased the RBF and RBF as a percent of cardiac output and lowered the RR to levels similar to normal controls (p < 0.02). Enalapril and CP71362 were equally effective in reducing the left ventricular end-diastolic pressure and total peripheral resistance in rats with myocardial infarction. These data demonstrate significant intrarenal vasoconstriction following myocardial infarction in the absence of detectable changes in mean arterial pressure or cardiac index. Converting enzyme inhibition or renin inhibition had similar beneficial effects on cardiorenal function, suggesting that both classes of compounds act by a similar mechanism to improve renal hemodynamics in congestive heart failure.     

Clinical experience with technetium-99m stannous polyphosphate for myocardial imaging

Myocardial imaging with technetium-99m stannous polyphosphate was performed on 46 patients. Eleven patients had no cardiac disease, 22 had acute myocardial infarction, and 13 had stable arteriosclerotic heart disease. Distinct patterns of myocardial activity were noted: (1) the patients with no obvious cardiac disease showed no cardiac activity; (2) stable arteriosclerotic heart disease showed faint, ill-defined cardiac activity, primarily in the anterior or inferior aspect of the left ventricle; (3) acute myocardial infarction showed intense, focal, well-defined activity, with a shape that characterized the location of the infarct.     

Development of Kozhevnikov''s epilepsy in tick-borne encephalitis

The examination was carried out in 787 patients with macrofocal myocardial infarction. The most frequently encountered variant of intraventricular block in males was the right bundle branch block, in females--the left bundle branch block. The rarest variant of intraventricular conductivity disorders in myocardial infarction was the left-posterior hemiblock. The prognostically severest variant of bilateral block consists in a combination of the right bundle branch block with the left-posterior hemiblock. The leading causes of death among the patients with myocardial infarction and intraventricular blocks were acute (cardiogenic shock, pulmonary oedema) and chronic cardiac insufficiency. In patients with bilateral blocks the frequent causes of death were, along with cardiac insufficiency, also arrhythmias (ventricular fibrillation, asystole).     

Cardiac death prediction and impaired cardiac sympathetic innervation assessed by MIBG in patients with failing and nonfailing hearts

BACKGROUND: Although cardiac sympathetic nerve dysfunction is related to poor clinical outcome, a critical sympathetic dysfunction level for predicting cardiac death is still unclear. The current study was designed to investigate which indices derived from metaiodobenzylguanidine (MIBG) imaging have prognostic value compared with clinical and cardiac function variables, and to determine the threshold of cardiac MIBG activity for identifying patients likely to suffer cardiac death in both failing and nonfailing hearts. METHODS AND RESULTS: Myocardial I-123-MIBG activity was quantified as a heart-to-mediastinum ratio in 414 consecutive patients, 173 (42%) of whom had symptomatic heart failure. After cardiac function measurements, patients were followed up with an end-point of cardiac or noncardiac death. During a mean follow-up period of 22 months, 37 cardiac deaths occurred: 23 resulted from heart failure, 9 were sudden cardiac deaths, and 5 were fatal myocardial infarctions. Multivariate analysis using the Wald chi2 and the Cox proportional hazard model revealed that late heart-to-mediastinum ratio, the use of nitrates, early heart-to-mediastinum ratio, and left ventricular ejection fraction were independent predictors of cardiac death; late heart-to-mediastinum ratio, New York Heart Association (NYHA) class, the presence of previous myocardial infarction, and age were independent predictors of heart failure and sudden cardiac death. Late heart-to-mediastinum ratio was the most powerful predictor of overall cardiac death among the variables. The Kaplan-Meier analysis showed that a late heart-to-mediastinum ratio of 1.74 or less, age greater than 60 years, the presence of myocardial infarction, and NYHA functional class 3 or 4 strongly indicated poor clinical outcomes. Furthermore, the more powerful incremental prognostic values were obtained by using MIBG imaging in combination with conventional clinical variables. CONCLUSIONS: Impaired cardiac sympathetic innervation assessed by MIBG activity has the greatest potential for predicting cardiac death and may be useful for identifying a threshold level for selecting patients at risk for death by heart failure, sudden cardiac death, and fatal myocardial infarction.     

The effect of the mean platelet volume on the short-term prognosis of acute myocardial infarct

INTRODUCTION AND OBJECTIVES: The increase of mean platelet volume in the late phase of myocardial infarction is an independent predictor for recurrent myocardial infarction and death, but the association between this finding and the short-term prognosis after acute myocardial infarction is unknown. The goals of this study were to assess the influence of mean platelet volume on the risk of death, recurrent ischemic events or cardiac heart failure during the in-hospital phase of myocardial infarction and to analyse the relationship between mean platelet volume and several demographic and clinical variables registered on admission. MATERIAL AND METHODS: A population of 1,082 patients with acute myocardial infarction were distributed in two groups according to the platelet volume measured on admission: group 1, mean platelet volume > 9 fl (n = 443) and group 2, mean platelet volume < or = 9 fl (n = 639). The difference between both groups on the end-point of this study were assessed by univariate and multivariate statistical methods. An univariate analysis was also applied to assess the relationship between platelet volume and the baseline variables. RESULTS: A mean platelet volume > 9 fl was associated with a significant increase of risk for the combined end-point considered (OR = 1.37; p = 0.026). By univariate analysis, an increased platelet volume was related to a higher risk of cardiac failure (OR = 1.46; p = 0.01) and a non-significant increase in the incidence of recurrent ischemic events (OR = 1.35; p = 0.07). In addition, a large platelet volume was also associated with a higher prevalence of prior myocardial infarction, arterial hypertension and diabetes mellitus. CONCLUSIONS: The results of this study suggest that the increase of mean platelet volume on admission is an independent risk factor for cardiac heart failure and is associated with a non significant higher rates of ischemic events during the recovery phase of acute myocardial infarction.