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Effects of early thrombolytic therapy (anistreplase versus streptokinase) on enzymatic and electrocardiographic infarct size in acute myocardial infarction. TEAM-2 Investigators.

The effects of thrombolytic therapy on enzymatic and electrocardiographic indexes of myocardial infarction were examined in 370 patients who were enrolled within 4 hours of onset of symptoms and were randomized to blinded therapy with intravenous anistreplase (30 U/5 min, n = 188) or streptokinase (1.5 million IU/1 hour, n = 182). Creatine kinase and its MB isoenzyme were initially measured every 4 to 6 hours, and lactic dehydrogenase (LDH) and its cardiac isoenzyme (LDH-1) every 8 to 12 hours. Electrocardiograms were obtained before, and at 90 minutes and 8 hours after starting thrombolysis, and on discharge. Enzymatic and electrocardiographic measures of infarction were compared between drug treatment and patency groups. Early patency was associated with significant reductions in peak values for each of 4 cardiac enzymes (averaging 21 to 25%, p less than 0.01 to 0.001), even though later rescue procedures were often used in the nonpatient group; times to peaks were also reduced for 3 of the enzymes. Treatment with anistreplase was associated with enzymatic peaks that tended to be lower than with streptokinase (6 to 16%), approaching or reaching significance for LDH (p less than or equal to 0.07) and LDH-1 (p less than or equal to 0.04); times to peaks were similar. Early patency favorably affected electrocardiographic indexes. Summed ST-segment elevations resolved more rapidly (p less than or equal to 0.04), summed Q-wave amplitude was reduced by 32% (p less than or equal to 0.01), and total QRS infarct score on discharge was 22% less (p less than or equal to 0.006) in those achieving early patency. Small differences in electrocardiographic indexes between the 2 drug treatment groups were not significant. These results support use of early reperfusion to reduce infarct size in acute myocardial infarction with administration of streptokinase and anistreplase.

Anistreplase↗

Beneficial effect of long-term beta blockade after acute myocardial infarction in patients without anterograde flow in the infarct artery.

Previous studies have shown that long-term survival after acute myocardial infarction (AMI) is improved by beta-adrenergic blockade and anterograde flow in the infarct artery. This study was done to assess the influence of beta blockade on mortality in survivors of AMI without anterograde flow. Over 9.5 years, 113 subjects (87 men and 26 women, aged 26 to 66 years) with AMI and no anterograde flow in the infarct artery and no disease of the other arteries were medically treated for 48 +/- 28 (mean +/- standard deviation) months. Forty-six patients received long-term beta blockade (group I), whereas 67 did not (group II). The groups were similar in age, sex, cardioactive medications, left ventricular performance and infarct artery. Of the 46 group I subjects, 1 (2%) died of cardiac causes; in contrast, 20 (30%) of the group II patients died of cardiac causes (p = 0.007 compared with group I). Thus, in survivors of AMI without anterograde flow in the infarct artery, mortality is markedly reduced by long-term beta blockade.

Adrenergic beta-Antagonists↗

Effect on outcome of the presence or absence of chest pain at initiation of recombinant tissue plasminogen activator therapy in acute myocardial infarction. The Thrombolysis in Myocardial Infarction Investigators.

To ascertain whether the outcome of patients with suspected myocardial infarction differs when chest pain is still present at initiation of thrombolytic therapy, participants in the Thrombolysis in Myocardial Infarction Phase II study, all of whom presented within 4 hours of symptoms onset, were retrospectively divided into 2 groups: (1) those with chest pain present at onset of intravenous thrombolysis, n = 3,000; and (2) those who were free of chest pain on beginning intravenous thrombolytic therapy, n = 337. Patients free of chest pain were older (58 vs 57 years, p = 0.01), more often women (23 vs 17%, p = 0.01), had fewer electrocardiographic leads with ST elevation (3.8 vs 4.1, p < 0.001), and the presenting event was confirmed less often as myocardial infarction than as chest pain without infarction (88 vs 96%, p < 0.001). There were no significant differences between the 2 groups for in-hospital death, reinfarction, recurrent ischemic events, stroke, overall hemorrhagic complications, coronary angioplasty or bypass surgery. At 6-weeks follow-up, more pain-free patients had resting ejection fraction > 0.55 (35 vs 31%, p = 0.001) and fewer developed congestive heart failure (12 vs 20%). At 1-year follow-up, fewer pain-free patients developed congestive heart failure (15 vs 21%, p = 0.009), but no differences existed between the 2 groups in frequency of death, reinfarction, coronary angioplasty, bypass surgery or anginal class. Thus, there are several observations in patients who were free of chest pain at onset of lytic therapy. (1) The majority developed enzymatic or electrocardiographic evidence of acute myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Relation between myocardial infarction site and pain location in Q-wave acute myocardial infarction.

Location, severity, duration, and time course of pain were assessed in 104 consecutive patients with either first or second, anterior or inferior Q-wave acute myocardial infarction (AMI). Pain severity was assessed using a visual analog scale. Pain location and radiation were similar in 48 patients with anterior and 56 patients with inferior wall AMI. Pain duration (6.1 +/- 6.4 vs 6.5 +/- 5.4 hours, p = NS) and severity (68 +/- 21 vs 61 +/- 21 mm, p = NS) were also similar. The pain was continuous in 34 patients with anterior (71%) and in 42 with inferior (75%) wall AMI. Among the 41 patients who did not receive thrombolytic therapy, 18 patients with continuous pain had a higher creatine kinase peak level than the remaining 23 patients with intermittent pain or preinfarction angina, or both (2,065 +/- 1,017 vs 1,162 +/- 994 IU, p < 0.01). The incidence of gastrointestinal symptoms was slightly higher in patients with inferior than anterior wall AMI (70% vs 48%, p < 0.05). Among 32 patients admitted with a second AMI, pain location was similar in 14 who had both infarcts in the same myocardial region, but was different in 12 of 18 (67%) who had a first and second infarct in different regions (p < 0.001). Thus, patients with anterior or inferior wall AMI experienced pain in similar body regions. However, in patients who presented with > 1 AMI, different locations of the infarction pain were highly predictive of ischemia occurring in different myocardial regions. Finally, patients with preinfarction angina or intermittent pain tended to have smaller infarcts.

Adult↗

Infection and infarction. Acute viral (and other) infection in the onset, pathogenesis, and mimicry of acute myocardial infarction.

Because a prospective controlled investigation showed a highly significant association of the onset of acute myocardial infarction with signs of preceding respiratory infection, the clinical, laboratory, experimental, and epidemiologic evidence more directly supporting this association was analyzed. Inflammation--specifically of infectious, usually viral, origin--has been shown by several lines of evidence to be capable of precipitating or mimicking clinical myocardial infarction. Myocardial biopsy is producing rapidly increasing confirmation that myocarditis can perfectly mimic clinical acute myocardial infarction. Coronary arteritis, with implications for vasospasm and thrombosis, is being increasingly demonstrated when deliberately sought in necropsy and biopsy material. Effects of blood-borne infectious agents, particularly viremia, on platelets in vivo and in vitro--aggregation and lysis with release of vasoactive substances--have even more serious potential for coronary thrombosis and vasospasm. It is not clear whether such mechanisms operate entirely independently or are more potent in high-risk patients, particularly in view of the demonstrable hypercoagulable state in many patients with coronary disease. Because of the great importance of confirming precipitating mechanisms for acute myocardial infarction (as well as its frequent mimic, myocarditis), intensive investigation of the relation between infection and infarction has important preventive and therapeutic implications.

Aged↗

Exercise capacity prior to myocardial infarction relates inversely to enzyme activity during infarction.

Epidemiological studies suggest that myocardial infarction occurs less commonly in physically fit individuals, indicating an inverse relationship between fitness and coronary arterial disease. In this study, the exercise capacity measured prior to infarction, was related to enzyme activity during subsequent infarction. Out of 512 consecutive male patients with acute infarction 35 were found who had previously performed an eligible exercise test. The exercise capacity was inversely related to enzymic activity during the infarction.

Adult↗

Does acute-phase beta-blockade reduce mortality in acute myocardial infarction by limiting infarct size?

The mechanism by which early intervention with beta-blockers reduces mortality in acute myocardial infarction is unclear. Therefore the effects of intravenous, followed by oral, metoprolol on indices of infarct size were studied in a double-blind fashion with a median delay of 6.75 hours from onset of symptoms. In 129 patients peak enzyme release and QRS score on the electrocardiogram were assessed, while myocardial perfusion score on thallium-201 scintigraphy was studied in 45 patients. There was a close correlation between all the indices of infarct size. While the correlation coefficients did not appear to be influenced by metoprolol treatment, the slope of the regression was affected. Peak aspartate aminotransferase and lactic dehydrogenase were lower by 11 and 7%, respectively, in the metoprolol-treated group, but no reduction was noted in QRS score or in thallium-201 perfusion defect size in the actively treated group. Thus, it seems likely that early intervention with metoprolol in acute myocardial infarction reduces mortality, not by limiting infarct size, but by some other mechanism.

Aspartate Aminotransferases↗

Protective action of a thromboxane synthetase inhibitor in preventing extension of infarct size in acute myocardial infarction.

U-63,557A, a new selective thromboxane synthetase inhibitor, was evaluated for its ability to prevent the extension of myocardial infarct size. Left coronary arteries of male Sprague-Dawley rats (230 - 270 g) were acutely ligated, producing a consistent model of myocardial infarction (MI) in rats analyzed 48 hours later. Left ventricular free wall (LVFW), creatine kinase (CK) activity, and amino-nitrogen concentrations were assayed as indices of infarct size. U-63,557A was administered intravenously in two doses (4 and 8 mg/kg) with a split schedule (2 min post-ischemia and either 4 or 24 hrs later). Administration of the thromboxane synthetase inhibitor significantly reduced both myocardial CK and amino-nitrogen loss at a dose of 8 mg/kg, but it was only slightly effective at 4 mg/kg. Drug treatment significantly increased the percent LVFW spared; 27 +/- 3% (vehicle) vs 43 +/- 7% and 52 +/- 7% (8 mg/kg). U-63,557A is an effective agent in myocardial ischemia for limiting the extension of infarct size after acute coronary artery ligation. Previous studies of other thromboxane synthetase inhibitors showed effectiveness in the early stages of MI. This study shows an effect on true infarct size 48 hours post-ligation, and suggests that inhibition of thromboxane A2 plays an important role in the pathogenesis of ischemic damage in the myocardium.

Animals↗

Time course of left ventricular dilation after myocardial infarction: influence of infarct-related artery and success of coronary thrombolysis.

Dilation of the left ventricle after myocardial infarction is common, occurs rapidly (within 2 weeks of infarction) and may be self-limited. To evaluate the time course of postinfarction left ventricular dilation and to assess the impact of successful coronary thrombolysis, serial radionuclide left ventricular volume analyses were performed in 36 patients undergoing attempted thrombolysis for acute transmural myocardial infarction. All patients underwent cardiac catheterization, coronary angiography and attempted thrombolysis within 7 h of the onset of symptoms. The site of coronary occlusion was the left anterior descending coronary artery in 17 patients, the right coronary artery in 18 and, in 1 patient, occluded bypass grafts to the right and left circumflex coronary arteries. Attempted reperfusion using a thrombolytic agent was successful in 22 individuals, occurring 5 +/- 1 h after the onset of symptoms. Gated radionuclide ventriculography was performed early (mean time 1 day after admission, n = 36), subacutely (mean time 11 days postinfarction, n = 36) and late after infarction (mean time 10.5 months, n = 25), and a geometric technique was used to measure serial left ventricular end-diastolic volume. Left ventricular end-diastolic volume for the entire group increased significantly (p less than 0.01) from 153 +/- 30 ml at baseline to 172 +/- 45 ml (at 11 days) to 220 +/- 63 ml (at 10.5 months). Twenty of 36 patients showed greater than 20% increase in left ventricular end-diastolic volume (dilation) with time. This appeared early in seven patients, occurred remote from infarction in seven others and showed a progressive pattern in six.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Does thrombolysis in myocardial infarction (TIMI) perfusion grade 2 represent a mostly patent artery or a mostly occluded artery? Enzymatic and electrocardiographic evidence from the TEAM-2 study. Second Multicenter Thrombolysis Trial of Eminase in Acute Myocardial Infarction.

One measure of the success of thrombolysis is the early patency status of the infarct-related coronary artery. The Thrombolysis in Myocardial Infarction (TIMI) study group designated patency grades 0 (occluded) or 1 (minimal perfusion) as thrombolysis failure and grade 2 (partial perfusion) or 3 (complete perfusion) as success. To evaluate their true functional significance, perfusion grades were compared with enzymatic and electrocardiographic (ECG) indexes of myocardial infarction in 359 patients treated within 4 h with anistreplase (APSAC) or streptokinase. Serum enzymes and ECGs were assessed serially. Patency was determined at 90 to 240 min (median 2.1 h) and graded by an observer who had no knowledge of patient data. Results for the two drug arms were similar and combined. Distribution of patency was grade 0 = 20%, n = 72; grade 1 = 8% n = 27; grade 2 = 16%, n = 58 and grade 3 = 56%, n = 202. Interventions were performed after angiography but within 24 h in 51% (n = 37), 70% (n = 19), 41% (n = 24) and 14% (n = 28) of patients with grades 0, 1, 2 and 3, respectively. Outcomes were compared among the four patency groups by the orthogonal contrast method. Patients with perfusion grade 2 did not differ significantly from those with grade 0 or 1 in enzymatic peaks, time to peak activity and evolution of summed ST segments, Q waves and R waves (contrast 2). Conversely, comparisons of patients with grade 3 perfusion with those with grades 0 to 2 yielded significant differences for enzymatic peaks and time to peak activity for three of the four enzymes (p = 0.02 to 0.0001) and ECG indexes of myocardial infarction (p = 0.02 to 0.0001) (contrast 3). Thus, patients with grade 2 flow have indexes of myocardial infarction similar to those in patients with an occluded artery (grades 0 and 1 flow). Only early grade 3 flow results in a significantly better outcome than that of the other grades. Because early achievement of grade 2 flow does not appear to lead to optimal myocardial salvage, the frequency of achieving grade 3 perfusion alone may best measure the reperfusion success of thrombolytic therapy.

Anistreplase↗

Invasive versus conservative strategy after thrombolytic therapy for acute myocardial infarction in patients with antecedent angina. A report from Thrombolysis in Myocardial Infarction Phase II (TIMI II).

OBJECTIVES: This study was designed to assess the possibility that a subgroup of patients at high risk for recurrent ischemia and reinfarction after thrombolytic therapy might benefit from early intervention. BACKGROUND: The Thrombolysis in Myocardial Infarction Phase II (TIMI II) study recently concluded that an obligatory invasive strategy after thrombolytic therapy offered no advantage over a more conservative strategy. METHODS: Data from the 3,534 patients enrolled in the TIMI II trial were analyzed to determine whether a history of antecedent angina before myocardial infarction identifies patients at high risk for subsequent ischemia and whether these patients might benefit from an invasive strategy. RESULTS: Within the TIMI II population, antecedent angina identified patients at increased risk for recurrent chest pain in the hospital (32.3% vs. 22.1%, p < 0.001) and recurrent infarction during the 1st year of follow-up (11.2% vs. 7.9%, p = 0.001) compared with that of patients without antecedent angina. Among patients assigned to the invasive strategy, coronary arteriography revealed that those with antecedent angina had a more severe residual stenosis of the infarct-related artery after thrombolytic therapy (77.1 +/- 0.7% vs. 73.0 +/- 0.9%, p < 0.001) and more multivessel disease (37.9% vs. 26.4%, p < 0.001). The clinical outcome of the patients with antecedent angina assigned randomly to either the invasive or the conservative strategy were compared. The invasive strategy patients had a slightly lesser incidence of recurrent chest pain in the hospital (29.9% vs. 34.8%, p = 0.13) and more negative (normal) findings on exercise tolerance tests (24.7 vs. 18.9%, p = 0.003), but there was no difference between the treatment strategies in the end point variable of recurrent myocardial infarction or death. CONCLUSIONS: These data demonstrate that antecedent angina identifies patients at increased risk for recurrent ischemic events after thrombolytic therapy. However, similar to the results for the overall population, the invasive strategy does not alter the risk of reinfarction or death compared with the conservative approach.

Administration, Oral↗

Outcome of patients with diabetes mellitus and acute myocardial infarction treated with thrombolytic agents. The Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) Study Group.

OBJECTIVES: This study was designed to assess outcome in patients with diabetes who received thrombolytic therapy and to determine whether differences in angiographic characteristics may account for the worse outcome observed in diabetic patients. BACKGROUND: Patients with diabetes are known to have a worse outcome after acute myocardial infarction than that of patients without diabetes. METHODS: Clinical and angiographic characteristics of the 148 patients with diabetes and the 923 patients without diabetes in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) trials were examined and analyzed. RESULTS: Patients with diabetes tended to be older (median age 59 vs. 56 years) and to have a higher incidence of hypertension and hyperlipidemia and a lower incidence of cigarette smoking. Patients with diabetes had significantly more severe anatomic disease (66% vs. 46% had multivessel disease, p < 0.0001), similar global left ventricular ejection fraction (49% vs. 51%) and worse noninfarct zone ventricular function (-0.13 vs. 0.32 SD/chord, p = 0.02) than that of nondiabetic patients. Angiographic patency rates at 90 min after thrombolytic therapy were similar in patients with and without diabetes (initial 90-min patency 71% vs. 70%). Diabetic patients had nearly twice the in-hospital mortality rate (11% vs. 6%, p < 0.02) and a higher incidence of pulmonary edema (11% vs. 4%, p = 0.001). Diabetic women had an especially high in-hospital mortality rate (21%). No retinal hemorrhages were observed. Although diabetes as an unadjusted variable was predictive of in-hospital (p < 0.02) and long-term (p = 0.003) mortality, after adjustment for baseline clinical and angiographic characteristics, diabetes was not found to have an independent influence on mortality. CONCLUSIONS: Patients with diabetes after myocardial infarction have a worse outcome than that of patients without diabetes despite similar rates of infarct vessel patency. However, diabetes was not found to be an independent risk factor for increased mortality. These findings suggest that diabetes itself is not a major risk factor for poor early outcome after thrombolytic therapy for myocardial infarction; rather, the secondary effects such as more extensive coronary artery disease account for the worse outcome.

Aged↗

Severity and response of chest pain during thrombolytic therapy for acute myocardial infarction: a useful indicator of myocardial salvage and infarct size.

OBJECTIVES: The purpose of this study was to determine noninvasively whether chest pain severity is predictive of the amount of myocardium at risk and whether the response of pain during thrombolysis is associated with myocardial salvage during acute myocardial infarction. BACKGROUND: The perception of chest pain and response to reperfusion therapy during acute myocardial infarction may provide important information for treatment benefit. Previous studies have been limited by the inability to measure myocardium at risk and myocardial salvage. METHODS: Sixty-two patients with acute myocardial infarction received an injection of technetium-99m sestamibi before thrombolysis and again at hospital discharge. Tomographic imaging was performed 1 to 6 h later. Myocardium at risk, infarct size and absolute myocardial salvage were derived from these images using previously described techniques and were expressed as a percent of the left ventricle. Salvage index was calculated by dividing myocardial salvage by the myocardium at risk. Chest pain severity was graded before thrombolysis as none, mild, moderate or severe. Chest pain response during thrombolytic therapy was graded as none, partial or completely resolved. RESULTS: There was no association between chest pain severity and myocardium at risk, but there was a weak trend toward greater myocardial salvage and salvage index (p = 0.09 and p = 0.12, respectively) for patients with more severe symptoms. Patients without chest pain at the start of thrombolysis still demonstrated significant salvage (11 +/- 11% of the left ventricle, p = 0.009). There was a significant association between chest pain response to therapy and both myocardial salvage (p = 0.03) and salvage index (p = 0.01). By multivariate analysis, chest pain severity and response of chest pain during thrombolysis were significant independent predictors of myocardial salvage, salvage index and infarct size. Thrombolysis was most effective in the 20 patients (32%) with moderate or severe chest pain and complete resolution of symptoms during thrombolysis (salvage of 79% to 89% of the area at risk). In the remaining 32 patients with chest pain, salvage of the area at risk was only 32%. CONCLUSIONS: These findings suggest that the assessment of chest pain before and after thrombolytic therapy is a readily available, useful indicator of the efficacy of the therapy.

Adult↗

Long-term physical training and left ventricular remodeling after anterior myocardial infarction: results of the Exercise in Anterior Myocardial Infarction (EAMI) trial. EAMI Study Group.

OBJECTIVES: The aim of this multicenter randomized study was to investigate whether long-term physical training would influence left ventricular remodeling after anterior myocardial infarction. BACKGROUND: Exercise is currently recommended for patients after myocardial infarction; however, the effects of long-term physical training on ventricular size and remodeling still have to be defined. METHODS: Patients with no contraindications to exercise were studied 4 to 8 weeks after anterior Q wave myocardial infarction and 6 months later by echocardiography at rest and bicycle ergometric testing. After the initial study, patients were randomly allocated to a 6-month exercise training program (n = 49) or a control group (n = 46). A computerized system was used to derive echocardiographic variables of ventricular size, function and topography. RESULTS: After 6 months, a significant (p < 0.01) increase in work capacity (from 4,596 +/- 1,246 to 5,508 +/- 1,335 kp-m) was observed only in the training group, whereas global ventricular size, regional dilation and shape distortion did not change in either the control or the training group. However, compared with patients with an ejection fraction > 40%, patients with an ejection fraction < or = 40% had more significant (p < 0.001) ventricular enlargement at entry and demonstrated further (p < 0.01) global and regional dilation after 6 months, in both the control and the training group (end-diastolic volume from 77 +/- 14 to 85 +/- 17 ml/m2 in the control group and from 74 +/- 11 to 77 +/- 15 ml/m2 in the training group; regional dilation from 46 +/- 18% to 57 +/- 21% in the control group and from 42 +/- 18% to 44 +/- 26% in the training group). Ventricular size and topography did not change in patients with an ejection fraction > 40%. CONCLUSIONS: Patients with poor left ventricular function 1 to 2 months after anterior myocardial infarction are prone to further global and regional dilation. Exercise training does not appear to influence this spontaneous deterioration. Thus, postinfarction patients without clinical complications, even those with a large anterior infarction, may benefit from long-term physical training without any additional negative effect on ventricular size and topography.

Electrocardiography↗

Predictors of in-hospital and 6-month outcome after acute myocardial infarction in the reperfusion era: the Primary Angioplasty in Myocardial Infarction (PAMI) trail.

OBJECTIVES: This study examined the predictors of in-hospital and 6-month outcome after different reperfusion strategies in acute myocardial infarction. BACKGROUND: Thrombolytic therapy and primary angioplasty are both widely applied as reperfusion modalities in patients with myocardial infarction. Although it is accepted that restoration of early patency of the infarct-related artery can reduce mortality and salvage myocardium, the optimal reperfusion strategy remains controversial, and the predictors of outcome in the reperfusion era have been incompletely characterized. METHODS: At 12 centers, 395 patients presenting within 12 h of onset of acute transmural myocardial infarction were prospectively randomized to receive tissue-type plasminogen activator (t-PA) or undergo primary angioplasty without antecedent thrombolysis. Sixteen clinical variables were examined with univariate and multiple logistic regression analysis to identify the predictors of clinical outcome. RESULTS: By univariate analysis, in-hospital mortality was increased in the elderly, women, patients with diabetes and in patients treated with t-PA as opposed to angioplasty. Only advanced age and treatment by t-PA versus angioplasty independently correlated with increased in-hospital mortality (6.5% vs. 2.6%, respectively, p = 0.039 by multiple logistic regression analysis). Similarly, the only variables independently related to in-hospital death or nonfatal reinfarction were advanced age and treatment by t-PA versus angioplasty (12.0% vs. 5.1%, p = 0.02). The reduction in in-hospital death or reinfarction with angioplasty versus t-PA was particularly marked in patients > or = 65 years of age (8.6% vs. 20.0%, p = 0.048). Furthermore, primary management with angioplasty versus t-PA was the most powerful multivariate correlate of freedom from recurrent ischemic events (10.3% vs. 28.0%, p = 0.0001). The independent beneficial effect of angioplasty on freedom from death or reinfarction was maintained at 6-month follow-up (8.2% vs. 17.0%, p = 0.02). CONCLUSIONS: In the reperfusion era, the two most powerful determinants of freedom from death, reinfarction and recurrent ischemia after myocardial infarction are young age and treatment by primary angioplasty.

Age Factors↗

Prognostic value of N-terminal proatrial natriuretic factor plasma levels measured within the first 12 hours after myocardial infarction. Thrombolysis in Myocardial Infarction (TIMI) II Investigators.

OBJECTIVES: The aim of the present study was to examine the relation between the plasma levels of the atrial peptide N-terminal proatrial natriuretic factor (proANF) measured during the 1st 12 h after myocardial infarction and 1-year mortality. BACKGROUND: The atrial peptides atrial natriuretic factor and N-terminal proANF are released from cardiac atria secondary to increased atrial pressures. The plasma levels of both peptides have been found to be related to long-term prognosis when measured in the subacute phase of myocardial infarction. METHODS: The study was of a retrospective case-control design studying patients enrolled in the Thrombolysis in Myocardial Infarction (TIMI) II trial. Seventy-six patients who died within the 1st year of enrollment in the trial were matched with another 76 patients who survived. N-terminal proANF was analyzed by radioimmunoassay at enrollment (no later than 4 h after the start of chest pain) and at 50 min, 5 h and 8 h after enrollment. RESULTS: At all studied time points the peptide levels were significantly higher in the case group than in the control group. At 8 h after enrollment, an N-terminal proANF value above a cutoff point of 1,500 pmol/liter was associated with an odds ratio for death of 3.9. CONCLUSIONS: The plasma level of N-terminal proANF, when measured during the 1st 12 h after the onset of chest pain, is related to 1-year mortality after myocardial infarction. Together with previous findings, these results suggest that N-terminal proANF measurements represent a valuable supplement to currently used prognostic indicators after myocardial infarction.

Aged↗

Long-term anticoagulant treatment after acute myocardial infarction. The Warfarin Re-Infarction Study.

High levels of fibrinogen and clotting factor VII are associated with an increased risk for subsequent death and cardiovascular disease in apparently healthy individuals. Furthermore, pathoanatomic studies and coronary angiography have confirmed a relationship between coronary thrombus formation and acute Q-wave infarction. Effective antithrombotic agents may prevent or limit thrombus formation and events related to thrombosis. The Warfarin Re-Infarction Study (WARIS) studied the effect of warfarin in survivors of acute myocardial infarction. Patients aged 75 years or less were randomized in a double-blind, placebo-controlled study to test whether long-term treatment with warfarin reduces the risk of death, reinfarction, and thromboembolic morbidity. A total of 1918 patients were screened for participation; 1214 were recruited. The mean follow-up was 37 months. Analyzed on an intention-to-treat basis, 123 (20%) in the placebo group died, versus 94 (15%) in the warfarin group, a risk reduction of 24% (P = 0.026). Considering patients on treatment or within 28 days after discontinuing the test medication, 92 in the placebo group died, as compared with 60 of the warfarin-treated patients, a risk reduction of 35% (P = 0.005). Relapsing myocardial infarction (fatal and nonfatal) was reduced by 43% (P = 0.0001). The incidence of cerebrovascular attacks was lower in the warfarin group (16 patients) than the placebo group (41 patients), a highly significant reduction of 61% (P = 0.0003). Serious bleeding occurred in 11 patients taking warfarin, an incidence of 0.6% per year. In conclusion, long-term anticoagulant therapy may be recommended after acute myocardial infarction.

Aged↗

Electrocardiographic infarct size assessment after thrombolysis: insights from the Acute Myocardial Infarction STudy ADenosine (AMISTAD) trial.

BACKGROUND: Noninvasive methods are needed to evaluate reperfusion success in patients with acute myocardial infarction (MI). The AMISTAD trial was analyzed to compare MI size and myocardial salvage determined by electrocardiogram (ECG) with technetium Tc 99m sestamibi single-photon emission computerized tomography (SPECT) imaging. METHODS: Of 236 patients enrolled in AMISTAD, 166 (70 %) with no ECG confounding factors and no prior MI were included in this analysis. Of these, group 1 (126 patients, 53%) had final infarct size (FIS) available by both ECG and SPECT. Group 2 (56 patients, 24%) had myocardium at risk, FIS, and salvage index (SI) assessed by both SPECT and ECG techniques. Aldrich/Clemmensen scores for myocardium at risk and the Selvester QRS score for final MI size were used. Salvage index was calculated as follows: SI = (myocardium at risk-FIS)/(myocardium at risk). RESULTS: In group 1, FIS was 15% (6, 24) as measured by ECG and 11% (2, 27) as measured by SPECT. In the adenosine group, FIS was 12% (6, 21) and 11% (2, 22). In the placebo group, FIS was 16.5% (7.5, 24) and 11.5% (3.0, 38.5) by ECG and SPECT, respectively. The overall correlation between SPECT and ECG for FIS was 0.58 (P = .0001): 0.60 in the placebo group (P = .0001) and 0.54 (P = .0001) in the adenosine group. In group 2, myocardium at risk was 23% (17, 30) and 26% (10, 50) with ECG and SPECT, respectively (P = .0066). Final infarct size was 17% (6, 21) and 12% (1, 24) (P < .0001). The SI was 29% (-7, 57) and 46% (15, 79) with ECG and SPECT, respectively (P = .0510). CONCLUSIONS: The ECG measurement of infarct size has a moderate relationship with SPECT infarct size measurements in the population with available assessments. This ECG algorithm must further be validated on clinical outcomes.

Adenosine↗