Emergency percutaneous coronary intervention (PCI) for the care of patients with ST-elevation myocardial infarction (STEMI).

There is general consensus that emergency percutaneous coronary intervention (PCI) is the preferred treatment for patients with ST-elevation myocardial infarction (STEMI), so long as it can be delivered in a timely fashion, by an experienced' operator and cardiac catheterization laboratory (CCL) team. STEMI is both a functional and structural issue. Although it has been recognized since the work of pioneering cardiologists and surgeons in Spokane, Washington, that approximately 88% of patients presenting within 6 hours of onset of STEMI have an occluded coronary artery, it is the pathophysiology of myocardial necrosis, and the varied consequences of necrosis that characterize STEMI. Accordingly, experience' of both primary operator and cardiac catheterization laboratory (CCL) crew, in performing an emergency PCI for STEMI, are as much a function of experience with the treatment of complex MI patients, as experience with coronary intervention. Rapidly achieving normal coronary artery flow, at both the macro and micro vascular levels, is the recognized key to aborting the otherwise progressive wavefront' of myocardial necrosis. The time urgency of decisions (Time is muscle') make emergency PCI for patients with on-going necrosis, more like emergency room (ER) care, than like most in-hospital or outpatient care. In general, most patients with acute coronary syndromes (ACS) are currently thought to have plaque rupture and/or erosion with subsequent thrombosis and embolization. Consequences of thrombo-embolism, such as slow flow' or no-reflow' are in addition to, the structural (anatomic) considerations of PCI in stable patients (such as ostial location; bifurcation involvement; heavy calcification; tortuosity of lesion or access to it; length of disease; caliber of infarct-artery; etc.). Good quality studies have provided strong support for the specific added value of glycoprotein IIb/IIIa inhibitors (especially abciximab), dual antiplatelet therapy (the addition of the thienopyridine, clopidogrel, to aspirin use), and bare-metal stents (BMS), for a broad range of STEMI patients. The added value of drug-eluting stents (DES) to bare-metal stents (BMS), primarily in terms of reducing restenosis and repeat revascularization, is supported by several randomized trials, and a number of registries, despite its being off-label' from a regulatory standpoint. The recognition of late stent thrombosis (LST) has raised additional issues, in choosing between these two options for specific STEMI patients. The added value of a number of other mechanical approaches to coronary thrombus, such as thrombus removal devices, and/or distal protection, are more controversial, and perhaps, patient specific. Whether intravascular ultrasound guidance (IVUS) for stent use should be used for the majority, or even a specific minority, of STEMI patients, is also controversial; late-stent thrombosis provides a counter-point. The advantages of developing a network approach to STEMI care, so as to optimize the number of patients receiving timely reperfusion, have been demonstrated in Prague, Denmark, and Minneapolis, among many places. The benefits of both bivalirudin (anti-thrombin drug with efficacy against clot-bound thrombin, which does not appear to stimulate platelets) and abciximab (glycoprotein IIb/IIIa inhibitor which is antibody to platelet receptors), as PCI adjuncts generally, and for STEMI patients, in particular, are supported by multiple trials. The specific choice of administering the bolus dose of either, or both, drugs via intra-coronary (IC) injection follows the precedents' of IC thrombolytics, and IC small-vessel vasodilators for no-reflow', but it has not been tested by prospective, randomized trials. Although rapid reperfusion is the first objective, one cannot ignore the other components of the oxygen delivery chain, and the importance of each of these components to on-going delivery of oxygen to all vital organs. A balance must be struck between doing those control' things which serve to stabilize other vital components of the oxygen-delivery chain, without digressing too long from the job of re-establishing brisk coronary flow. The clinical and angiographic heterogeneity of STEMI patients and the array of available therapeutic approaches make it impossible to obtain specific randomized trial direction for many of the clinical decisions in an individual emergency PCI for STEMI. There are a range of reasonable/ appropriate therapeutic choices for a given emergent PCI performed by multiple experienced and competent operators. The treatment of STEMI, and high-risk non-STEMI, patients, by means of emergent PCI, is among the most challenging and rewarding arenas in contemporary medicine.

IL-8 is an angiogenic factor in human coronary atherectomy tissue.

BACKGROUND: Interleukin-8 (IL-8), a CXC chemokine that induces the migration and proliferation of endothelial cells and smooth muscle cells, is a potent angiogenic factor that may play a role in atherosclerosis. Previously, IL-8 has been reported in atherosclerotic lesions and circulating macrophages from patients with atherosclerosis. Therefore, we sought to determine whether IL-8 plays a role in mediating angiogenic activity in atherosclerosis. METHODS AND RESULTS: Homogenates from 16 patients undergoing directional coronary atherectomy (DCA) and control samples from the internal mammary artery (IMA) of 7 patients undergoing bypass graft surgery were assessed for IL-8 content by specific ELISA, immunohistochemistry, and in situ hybridization for IL-8 mRNA. The contribution of IL-8 to net angiogenic activity was assessed using the rat cornea micropocket assay and cultured cells. IL-8 expression was significantly elevated in DCA samples compared with IMA samples (1.71+/-0.6 versus 0.05+/-0.03 ng/mg of total protein; P<0.01). Positive immunolocalization of IL-8 was found exclusively in DCA tissue sections, and it correlated with the presence of factor VIII-related antigen. In situ reverse transcriptase polymerase chain reaction revealed the expression of IL-8 mRNA in DCA tissue. Corneal neovascular response, defined by ingrowth of capillary sprouts toward the implant, was markedly positive with DCA pellets, but no constitutive vessel ingrowth was seen with IMA specimens. Neutralizing IL-8 attenuated both the in vivo corneal neovascular response and the in vitro proliferation of cultured cells. CONCLUSIONS: The results suggest that, in human coronary atherosclerosis, IL-8 is an important mediator of angiogenesis and may contribute to plaque formation via its angiogenic properties.

Cardiogenic shock in patients with acute ischemic syndromes with and without ST-segment elevation.

BACKGROUND: Cardiogenic shock is usually considered a sequela of ST-segment elevation myocardial infarction. There are limited prospective data on the incidence and significance of shock in non-ST-segment elevation patients. This study assessed the incidence and outcomes of cardiogenic shock developing after enrollment among patients with and without ST-segment elevation in the Global Use of Strategies To Open Occluded Coronary Arteries (GUSTO)-IIb trial. METHODS AND RESULTS: Among 12,084 patients in GUSTO-IIb who did not present with cardiogenic shock, 4092 (34%) had and 7991 (66%) did not have ST-segment elevation on the enrollment ECG. Cardiogenic shock developed in 4.2% of ST-segment elevation patients compared with 2.5% of patients without ST-segment elevation (odds ratio, 0. 581; 95% CI, 0.472 to 0.715; P<0.001). Shock developed significantly later among patients without ST-segment elevation. There were significant differences in baseline characteristics between shock patients with and without ST-segment elevation: Patients without ST-segment elevation were older, more frequently had diabetes mellitus and 3-vessel disease, but had less TIMI grade 0 flow at angiography. Regardless of the initial ECG, mortality was high: 63% among patients with ST-segment elevation and 73% in those without ST-segment elevation. CONCLUSIONS: Cardiogenic shock occurs in the setting of acute ischemic syndromes regardless of whether ST-segment elevation is present. The incidence, patient characteristics, timing, clinical course, and angiographic findings differ between the 2 groups. Mortality from cardiogenic shock is similarly high among patients with and without ST-segment elevation.

Reperfusion therapy in inferior myocardial infarction.

This review summarizes the multicenter trial results of reperfusion therapy for treatment of inferior myocardial infarction. Therapy with intracoronary streptokinase or intravenous recombinant tissue plasminogen activator (rt-PA) produced higher patency rates than did intravenous streptokinase. Reocclusion was more common when the right coronary artery was the infarct-related artery, irrespective of treatment strategy. Left ventricular ejection fraction was improved compared with that in control patients, especially when the time from symptom onset was brief or when patency rates were high. Enzymatic infarct size was reduced in treated patients. A trend toward mortality reduction in treated patients was found in four studies and was statistically significant in the Second International Study of Infarct Survival (ISIS-2) trial. Precordial ST segment depression in inferior myocardial infarction is associated with values for enzyme release, left ventricular ejection fraction and mortality similar to those in anterior infarction. Patients with inferior infarction who present within 6 h of symptom onset with precordial ST segment depression should be considered candidates for intravenous thrombolytic therapy with rt-PA; immediate cardiac catheterization and possible coronary angioplasty should be limited to those who are in hemodynamically unstable condition. Patients without precordial ST segment depression who present within 3 h of symptom onset and who do not have risk factors for bleeding should also be candidates for intravenous rt-PA therapy. The prognosis of other patients with inferior myocardial infarction is so good that the issue of thrombolytic therapy remains unsettled.

Revisiting reperfusion therapy in inferior myocardial infarction.

Although thrombolytic therapy for acute myocardial infarction (MI) is recommended without regard for infarct location, treatment results are less impressive for inferior than for anterior MI because the amount of myocardium at risk is smaller and less strategically located, and the mortality risk is lower. Whereas the risks associated with anterior MI are relatively constant, high risk subsets of patients with an inferior MI can be identified by simple electrocardiographic criteria, including left precordial ST segment depression, complete atrioventricular heart block and right precordial ST segment elevation. Unfortunately, none of the placebo-controlled, randomized trials have analyzed the benefit of thrombolytic therapy for inferior MI in high risk versus low risk subsets. Thrombolytic therapy should be more successful in reducing infarct size and decreasing mortality in high risk patients with an inferior MI. Thrombolytic therapy may not decrease hospital mortality in low risk patients (baseline risk 2% to 4%) or those with symptom duration > 6 h. Whereas it is arguable whether coronary angioplasty is superior to thrombolytic therapy in anterior MI, there are no mortality data to support using angioplasty as a primary or rescue reperfusion strategy instead of thrombolytic therapy in inferior MI, unless thrombolytic contraindications are present or the patient is in cardiogenic shock.

Limitations of thrombolytic therapy for acute myocardial infarction complicated by congestive heart failure and cardiogenic shock.

As many as one quarter of patients treated with thrombolytic therapy present with congestive heart failure or cardiogenic shock. Although thrombolytic therapy has been shown to limit infarct size, preserve left ventricular ejection fraction and decrease mortality in most subgroups of patients, no apparent benefit has been demonstrated in patients with clinical left ventricular dysfunction. The lack of correlation between ejection fraction and other measurements of left ventricular dysfunction such as exercise time, cardiac output, filling pressures, activation of the neurohumoral system and regional perfusion bed abnormalities may partly explain this paradox. Alternatively, lower perfusion rates, higher reocclusion rates, associated mechanical complications or completed infarction may explain these findings. Preliminary data indicate that emergency coronary angioplasty or bypass graft surgery improves survival in selected patients with cardiogenic shock. Because these findings suggest that restoration of infarct artery patency is especially important in patients with clinical left ventricular dysfunction, additional studies are needed in these patients to investigate the potential benefit that new thrombolytic strategies, inotropic or vasodilator agents or intraaortic balloon counterpulsation might offer by augmenting coronary blood flow and improving reperfusion rates. Currently, acute mechanical revascularization should be considered for patients who present with congestive heart failure associated with hypotension or tachycardia and for patients with cardiogenic shock.

Treatment of recurrent ischemia after thrombolysis and successful reperfusion for acute myocardial infarction: effect on in-hospital mortality and left ventricular function.

To determine the effect of treatment of recurrent ischemia after reperfusion for acute myocardial infarction on in-hospital mortality and left ventricular function recovery and to identify patients at highest risk of serious consequences in the event of recurrent ischemia in this setting, 405 consecutively treated patients were studied retrospectively. All patients received intravenous thrombolytic therapy within 6 h of ST segment elevation-documented infarction and had angiographic confirmation of their reperfusion status performed within 120 min of treatment. Three hundred three patients had successful reperfusion with or without rescue angioplasty and had no recurrent ischemia (group 1), 74 patients had initially successful reperfusion but subsequent recurrent ischemia (group 2) and 28 patients had failed reperfusion (group 3). The in-hospital mortality in groups 1 to 3 was 2.0%, 14.9% and 32.1%, respectively (p less than 0.001) and the change from baseline to prehospital discharge left ventricular ejection fraction was 1.2 +/- 9.3%, -0.8 +/- 8.7% and -4.3 +/- 5.3%, respectively (p = NS). Within the recurrent ischemia group (group 2), multiple regression analysis found absence of cardiogenic shock at presentation (p = 0.002) and successful treatment initiated within 90 min of recurrent ischemia (p = 0.045) to be the only variables independently correlated with in-hospital survival. Later successful reperfusion was not associated with improved hospital survival. The timing and success of treatment did not affect recovery of global or regional left ventricular function in the patients with paired angiographic studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative study of coronary flow reserve, coronary anatomy and results of radionuclide exercise tests in patients with coronary artery disease.

A comparative assessment of regional coronary flow reserve, quantitative percent diameter coronary stenosis and exercise-induced perfusion and wall motion abnormalities was performed in 39 patients with coronary artery disease. Coronary flow reserve was determined by a digital angiographic technique utilizing contrast medium as the hyperemic agent. Percent diameter stenosis was calculated by an automated quantification program applied to orthogonal cineangiograms. Thallium-201 scintigraphy and radionuclide ventriculography were used to assess regional perfusion and wall motion abnormalities, respectively, at rest and during exercise. In Group A, 19 patients without transmural infarction or collateral vessels, coronary flow reserve was inversely related to percent diameter stenosis (r = -0.61, p less than 0.0001), and scintigraphic abnormalities occurred only in vascular distributions with a coronary flow reserve of less than 2.00. There was a strong relation among abnormal regional exercise results, stenoses greater than 50% and reactive hyperemia of less than 2.00. Patients with multivessel disease, however, often had normal exercise scintigrams in regions associated with greater than 50% stenosis and low coronary flow reserve when other regions had a lower coronary flow reserve or higher grade stenosis, or both. In Group B, 20 patients with angiographically visible collateral vessels, 12 of whom had prior myocardial infarction, coronary flow reserve correlated less well with percent diameter stenosis than in Group A (r = -0.47, p less than 0.004). As in Group A patients, there was a significant relation between abnormal exercise test results and stenoses greater than 50%. However, reactive hyperemia values were generally lower than in Group A, and positive exercise stress results were strongly correlated only with highly impaired flow reserves of 1.3 or less. In Group B patients, the coronary flow reserve of vessels with less than 50% stenosis was significantly lower than that of similar vessels in Group A patients (2.40 +/- 0.79 versus 1.56 +/- 0.43; p less than 0.0002). It is concluded that: there is a general relation between quantitative percent diameter stenosis and reactive hyperemia that is not of sufficient precision to allow accurate prediction of coronary flow reserve in individual cases; exercise scintigraphic abnormalities are usually associated with low coronary flow reserve, and the relation between these two functional tests is stronger than the relation between exercise test results and quantitative percent diameter stenosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Prospects for the use of antagonists to the platelet glycoprotein IIb/IIIa receptor to prevent post-angioplasty restenosis and thrombosis.

Despite many advances since its inception in humans in 1977, coronary angioplasty continues to be limited by the problems of abrupt arterial closure and late restenosis. Excessive platelet deposition at the site of angioplasty undoubtedly plays an important role in the pathophysiology of both of these problems. Monoclonal antibodies and snake venom-derived or synthetic peptides directed against a common protein recognition sequence on the platelet glycoprotein IIb/IIIa receptor are currently in the early stages of preclinical and clinical testing and hold promise of preventing abrupt closure and restenosis by inhibiting platelet function. Whether any of these agents will eventually be commonly used in clinical practice will depend on their effects on the complex pathophysiology of these problems and on their safety profile when administered to patients who are likely to receive other antithrombotic medications and who are instrumented for coronary angioplasty.

Thrombolysis plus aortic counterpulsation: improved survival in patients who present to community hospitals with cardiogenic shock.

OBJECTIVES: We sought to explore the potential benefit of combining intraaortic balloon counterpulsation (IABP) with thrombolysis for acute myocardial infarction (MI) complicated by cardiogenic shock. BACKGROUND: In community hospitals, this condition is usually managed with thrombolysis alone. METHODS: We reviewed the charts of 335 patients from two community hospitals who presented with acute MI and had cardiogenic shock between 1985 and 1995. RESULTS: Of 46 patients who underwent thrombolysis within 12 h of acute infarction with confirmed cardiogenic shock, 27 underwent IABP and 19 did not. Age, systolic blood pressure with shock, pulmonary artery catheter use, pulmonary capillary wedge pressure and the incidence of diabetes mellitus and anterior MI did not differ between groups. Patients treated with IABP were somewhat more likely to have prior MI and had a significantly greater cardiac index (2.0 vs. 1.5 liters/min per m2, p = 0.04). Although no deaths occurred within 2 h of presentation, patients not treated with IABP tended to die earlier (6.8 +/- 5 vs. 23.8 +/- 19 h, p = 0.13). Patients treated with IABP had a significantly higher rate of community hospital survival (93% vs. 37%, p = 0.0002), and more of them were transferred for revascularization (85% vs. 37%). Of 30 patients transferred for revascularization, 27 underwent angioplasty or bypass surgery; hospital survival was 74%. Patients treated with IABP also had a significantly higher overall hospital and 1-year survival rate (67% vs. 32%, p = 0.019). CONCLUSIONS: Survival may be enhanced and transfer for revascularization facilitated when community hospitals use both thrombolysis and IABP to treat patients with acute MI complicated by cardiogenic shock.

Abnormal coronary flow reserve and abnormal radionuclide exercise test results in patients with normal coronary angiograms.

Coronary flow reserve, exercise thallium-201 scintigraphy and exercise radionuclide ventriculography were compared in 18 patients with chest pain and angiographically normal coronary arteries. Regional exercise thallium-201 perfusion was abnormal in three patients, regional exercise wall motion was abnormal in three other patients and results of both tests were abnormal in one additional patient. Left ventricular ejection fraction responses were abnormal in five of these seven patients. The coronary flow reserve of arterial distributions with abnormal perfusion or regional dysfunction was significantly lower than that of distributions associated with normal radionuclide results (1.42 +/- 0.23 versus 2.58 +/- 0.83, p less than 0.001). All patients with abnormal scintigraphic results had low coronary flow reserve (less than 1.95) in at least one distribution. Perfusion abnormalities appeared to be more localized in the arterial distributions with the lowest flow reserve. Only two patients had low flow reserve (less than 1.95) with normal scintigraphic results; both were hypertensive. These data suggest that abnormal exercise scintigraphic findings in patients with angiographically normal coronary arteries and chest pain are indicative of true blood flow or perfusion abnormalities.

Predictors of success for coronary angioplasty performed for acute myocardial infarction.

To evaluate the predictors and likelihood of success for coronary angioplasty performed in the setting of acute myocardial infarction, 300 consecutive patients with 321 coronary stenoses were studied retrospectively. Success was defined as final diameter stenosis less than 70% and Thrombolysis in Myocardial Infarction (TIMI) flow grade greater than or equal to 2. Nine clinical variables and 15 angiographic variables were assessed. Seventy-nine percent of patients were men; the mean age was 56 +/- 11 years, and 54% of patients also received thrombolytic therapy. The mean left ventricular ejection fraction was 46 +/- 11%, and 18 patients (6%) were in cardiogenic shock. Angioplasty success in the infarct-related artery was achieved in 240 patients (80%). In 177 total occlusions (TIMI flow grade less than or equal to 1), the success rate was 75.7% and success was independently predicted by 1) an ejection fraction greater than 30% (p = 0.001); 2) no arterial bend greater than or equal to 45 degrees at the site of angioplasty (p = 0.008); and 3) no triple vessel disease (p = 0.014). In 144 subtotal occlusions (TIMI flow grade greater than or equal to 2), procedural success was achieved in 84.7% and was predicted by 1) absence of thrombus greater than 5 mm (p = 0.023), and 2) absence of other stenoses greater than or equal to 50% in the same artery (p = 0.043), whereas patency without further emergency intervention was achieved in 71.7% and was predicted only by patient age less than or equal to 60 years and absence of cardiogenic shock.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary angioplasty as primary therapy for acute myocardial infarction 6 to 48 hours after symptom onset: report of an initial experience.

Recent randomized trials in acute myocardial infarction suggest that infarct size reduction need not be achieved for intravenous streptokinase to improve patient survival. If this is the case, attempts to achieve late revascularization may be justified. To assess the results of late primary coronary angioplasty performed in the setting of acute myocardial infarction, the clinical and angiographic data as well as hospital outcome of 139 consecutive patients treated with coronary angioplasty without prior thrombolytic therapy 6 to 48 h after the onset of chest pain (late group) were compared with those of 117 patients treated with primary angioplasty less than 6 h after the onset of chest pain (early group); time to angioplasty was assessed as a covariate of survival. In the 139 patients treated greater than or equal to 6 h after the onset of chest pain, the mean age (+/- SD) was 57 +/- 12 years and the median time to angioplasty was 15 h; 61% had multivessel disease, 14% were in cardiogenic shock and the mean left ventricular ejection fraction was 44 +/- 12%. Angioplasty was successful (final diameter stenosis less than 70% and Thrombolysis in Myocardial Infarction [TIMI] flow grade greater than or equal to 2) in 78% of patients. Successful angioplasty was associated with a 5.5% in-hospital mortality rate, whereas unsuccessful angioplasty was associated with a 43% hospital mortality rate (p less than 0.001). Multivariate testing in all patients identified four independent predictors of in-hospital death: cardiogenic shock (p less than 0.001), unsuccessful angioplasty (p = 0.001), ejection fraction less than or equal to 30% (p = 0.002) and patient age (p = 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)

Implications for patient triage from survival and left ventricular functional recovery analyses in 500 patients treated with coronary angioplasty for acute myocardial infarction.

The in-hospital course of 500 consecutive patients treated with coronary angioplasty for acute myocardial infarction was reviewed in relation to their clinical and angiographic presentation and angioplasty outcome to determine which patients benefit most from successful angioplasty in this setting. Patient age was 56 +/- 11 years (mean +/- SD) and 78% were men; 46% had anterior myocardial infarction, 49% received concomitant intravenous thrombolytic therapy, left ventricular ejection fraction was 47 +/- 11% and median time to angioplasty was 4.7 h (range 1 to 24). Angioplasty was successful in 78% of patients and partially successful in 7% of patients; the overall in-hospital mortality rate was 10.2%. Multivariate analysis found six independent correlates (p less than 0.05) of in-hospital mortality: left ventricular ejection fraction less than or equal to 30%, lack of postangioplasty infarct artery patency, age greater than 65 years, recurrent ischemia after successful angioplasty, emergency bypass surgery and arterial pressure on admission to the catheterization laboratory less than 100 mm Hg. After consideration of these predictors of survival in multivariate analyses, angioplasty success still was independently correlated with improved in-hospital survival for patients with cardiogenic shock (p = 0.002) and anterior myocardial infarction (p = 0.007). A trend toward an independent beneficial effect of successful angioplasty on survival was also noted in patients with inferior wall infarction and precordial ST segment depression (p = 0.063) and for all patients who were hypotensive on admission to the catheterization laboratory, regardless of the infarct site (p = 0.057).(ABSTRACT TRUNCATED AT 250 WORDS)

Thrombolysis and Angioplasty in Myocardial Infarction (TAMI-1) trial: influence of infarct location on arterial patency, left ventricular function and mortality.

The influence of infarct location on arterial patency, left ventricular function and mortality after 150 mg of intravenous recombinant tissue-type plasminogen activator (rt-PA) and selective coronary angioplasty was studied in 386 patients with acute myocardial infarction. In 329 patients with acute and 1 week angiograms, the 90 min infarct-related artery patency rate after rt-PA in the left anterior descending, the left circumflex and the right coronary artery was 77, 68 and 68%, respectively. Angioplasty, performed in half the patients, resulted in a final acute patency rate of 93%, which was not related to arterial distribution. Repeat catheterization and revascularization were required in 12% of patients before day 7 and were independent of arterial distribution. The reocclusion rate for the right coronary artery (21%) was higher than that for the left anterior descending (12%) or left circumflex (5%) artery (p = 0.01). Acute and 1 week contrast ventriculograms suitable for analysis were available in 266 patients. Whereas serial left ventricular ejection fraction did not improve during the course of this study, serial regional wall motion (centerline chord method) improved in each arterial distribution. The in-hospital mortality rate of 6% was not related to arterial distribution, although death was twice as likely with proximal compared with distal lesions. Ten of 11 patients who died in the group with the left anterior descending artery as the infarct-related artery had a lesion proximal to the first septal perforator branch.(ABSTRACT TRUNCATED AT 250 WORDS)

Precordial ST segment depression predicts a worse prognosis in inferior infarction despite reperfusion therapy. The Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) Study Group.

The impact of associated precordial ST segment depression in inferior myocardial infarction on angiographic and clinical outcomes after thrombolytic therapy and selective coronary angioplasty was studied in 583 patients with acute myocardial infarction. Anterior infarction (Group I), inferior infarction with precordial ST segment depression (Group II) and inferior infarction without precordial ST segment depression (Group III) were present in 289, 135 and 159 patients, respectively. Precordial ST segment depression was more frequent in circumflex than right coronary infarct-related arteries (44 [71%] of 62 versus 91 [40%] of 230; p = 0.000). Although acute patency rates were not statistically different, there was a trend toward different patency rates at day 7 (Group I 88%, Group II 84%, Group III 80%; p = 0.089) partly because of insignificantly higher reocclusion rates in inferior infarction without precordial ST segment depression (Group I 11%, Group II 10%, Group III 18%, p = 0.104). Infarct zone regional wall motion (standard deviations/chord) in inferior infarction was lower with precordial ST segment depression, both acutely (Group I -2.8 +/- 0.9, Group II -2.5 +/- 1.2, Group III 2.0 +/- 1.1; p = 0.000) and at day 7 (Group I -2.2 +/- 1.1, Group II -2.3 +/- 1.1, Group III -1.9 +/- 1.3; p = 0.011). Precordial ST segment depression was associated with a lower ejection fraction in inferior infarction both acutely (Group I 47 +/- 11%, Group II 53 +/- 11%, Group III 58 +/- 9%; p = 0.000) and at day 7 (Group I 49 +/- 12%, Group II 53 +/- 10%, Group III 58 +/- 8%; p = 0.000). Complication rates tended to be higher in inferior infarction when precordial ST segment depression was present. Mortality rates for Groups I, II and III were 8%, 6% and 5%, respectively. These results suggest that precordial ST segment depression in inferior infarction predicts a worse ventriculographic and clinical outcome despite reperfusion therapy.

Cardiogenic shock complicating acute myocardial infarction: the use of coronary angioplasty and the integration of the new support devices into patient management.

Conventional therapy for cardiogenic shock complicating acute myocardial infarction continues to be associated with a high in-hospital mortality rate. Hemodynamic support with new mechanical devices and emergency coronary revascularization may alter the long-term prognosis for patients with this complication. Between July 1985 and March 1990, 68 patients presented to the University of Michigan with acute myocardial infarction and cardiogenic shock. Interventions performed included thrombolytic therapy (46%), intraaortic balloon pump counterpulsation (70%), cardiac catheterization (86%), coronary angioplasty (73%), emergency coronary artery bypass grafting/ventricular septal defect repair (15%), Hemopump insertion (11%), percutaneous cardiopulmonary support (4%) and ventricular assist device (3%). The 30-day survival rate was significantly better in patients who had successful angioplasty of the infarct-related artery than in patients with failed angioplasty (61% vs. 7%, p = 0.002) or no attempt at angioplasty (61% vs. 14%, p = 0.003). This difference was maintained over the 1-year follow-up period. The only clinical variable that predicted survival was age less than 65 years. The early use of the new support devices in 10 patients was associated with death in 8 (80%), but this poor outcome may reflect a selection bias for an especially high risk population. Collectively, these recent data continue to suggest that emergency revascularization with angioplasty may reduce the mortality rate, but further study is required to define optimal utilization and integration of new support devices.

Community hospital administration of intravenous tissue plasminogen activator in acute myocardial infarction: improved timing, thrombolytic efficacy and ventricular function.

As an investigational fibrinolytic agent for acute myocardial infarction, intravenous recombinant tissue-type plasminogen activator (rt-PA) has been administered primarily in tertiary care and university centers. To determine the value of early initiation of such therapy, two satellite community hospital emergency rooms were established for use of rt-PA and the experience was compared among 142 consecutive patients who were transferred to a regional center for acute cardiac catheterization after intravenous rt-PA therapy. In Group I (n = 19), patients received rt-PA after interhospital transport to the regional center, but before cardiac catheterization. In Group II (n = 70), rt-PA therapy was initiated by the helicopter physician and nurse team after their arrival at the local community hospital emergency room. Group III patients (n = 53) had rt-PA administered in the local community hospital by the emergency room physician. Group III patients had earlier initiation of therapy (2.1 +/- 0.8 hours in Group III versus 3.8 +/- 1.2 hours in combined Groups I and II, p less than 0.001) and an increased rate of infarct vessel recanalization on the 90 minute coronary angiogram (81 in Group III versus 67% in combined Groups I and II, p = 0.057). The patients in Group III had a higher acute left ventricular ejection fraction (54 +/- 8% versus 50 +/- 9.5% in combined Groups I and II, p less than 0.01) and a trend toward an increased 7 day ejection fraction (55.5 +/- 9% versus 51.7 +/- 9.5%, respectively, p = 0.08).(ABSTRACT TRUNCATED AT 250 WORDS)

A randomized placebo-controlled trial of combined early intravenous captopril and recombinant tissue-type plasminogen activator therapy in acute myocardial infarction.

The adjunctive use of intravenous captopril with tissue plasminogen activator early during acute myocardial infarction offers theoretic advantages of diminishing left ventricular volume, preventing ventricular dilation and improving patient survival. To test the safety and efficacy of combined early administration of intravenous captopril and recombinant tissue-type plasminogen activator (rt-PA), 38 patients treated with rt-PA 3 +/- 0.3 h (mean +/- SE) after the onset of myocardial infarction were randomized to intravenous followed by oral captopril or placebo therapy. They underwent cardiac catheterization with measurement of hemodynamic variables and left ventricular function and determination of serum renin, angiotensin and aldosterone levels on days 1 and 7. Oral administration of the selected agent was continued for 3 months along with other antianginal medications, including nonangiotensin-converting enzyme inhibitor vasodilators. Repeat measurements of left ventricular function were obtained before hospital discharge and at 3 months. There were no significant differences in baseline clinical characteristics between groups. One patient in the captopril-treated group became hypotensive during intravenous therapy, requiring discontinuation of treatment. Compared with the placebo-treated group, the captopril-treated group had significant reductions at day 7 in left ventricular end-diastolic pressure (22.5 +/- 1.5 versus 16.3 +/- 1.6 mm Hg, p less than 0.01) and mean systemic arterial pressure (93.6 +/- 3.3 versus 86.2 +/- 2.7 mm Hg, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Rapid hemodynamic improvement after reperfusion during right ventricular infarction.

OBJECTIVES: This study sought to determine the effects of reperfusion on hemodynamic status and hospital course in patients with right ventricular infarction. BACKGROUND: In contrast to the relatively low risk associated with acute inferior myocardial infarction, right ventricular infarction is associated with higher in-hospital morbidity and mortality. However, the potential benefits of reperfusion in patients with right ventricular infarction are unknown. Consequently, this study evaluated the potential benefits of primary angioplasty in patients with right ventricular infarction. METHODS: Of 141 consecutive patients admitted to the hospital for inferior myocardial infarction, 27 were identified as having right ventricular involvement by electrocardiographic and hemodynamic criteria. Seventeen patients achieved patency of the infarct-related right coronary artery by primary coronary angioplasty within 24 h of hospital admission, but 10 patients did not. All patients had invasive hemodynamic monitoring at the time of hospital admission, and subsequent serial hemodynamic status and clinical events were recorded. RESULTS: Patients with successful reperfusion demonstrated improved right atrial pressure, pulmonary capillary wedge pressure and right atrial/pulmonary capillary wedge pressure ratio as early as 8 h after reperfusion, whereas patients without reperfusion had no hemodynamic improvement over 24 h. Right atrial pressure demonstrated the greatest 8-h improvement after successful reperfusion (15.4 +/- 0.8 to 8.4 +/- 0.8 mm Hg [mean +/- SD], p < 0.05) but was unchanged without reperfusion (13.7 +/- 0.9 to 13.9 +/- 0.8 mm Hg, p = NS). Additionally, persistently elevated right atrial pressure was associated with increased mortality. CONCLUSIONS: Reperfusion in the setting of right ventricular infarction leads to rapid hemodynamic improvement and may result in improved survival.