Reperfusion therapy for acute myocardial infarction: Concepts and controversies from inception to acceptance.

More than 20 years of misconceptions derailed acceptance of reperfusion therapy for acute myocardial infarction (AMI). Cardiologists abandoned reperfusion for AMI using fibrinolytic therapy, explored in 1958, because they no longer attributed myocardial infarction to coronary thrombosis. Emergent aortocoronary bypass surgery, pioneered in 1968, remained controversial because of the misconception that hemorrhage into reperfused myocardium would result in infarct extension.

Anatomic versus physiologic assessment of coronary artery disease. Role of coronary flow reserve, fractional flow reserve, and positron emission tomography imaging in revascularization decision-making.

Angiographic severity of coronary artery stenosis has historically been the primary guide to revascularization or medical management of coronary artery disease. However, physiologic severity defined by coronary pressure and/or flow has resurged into clinical prominence as a potential, fundamental change from anatomically to physiologically guided management. This review addresses clinical coronary physiology-pressure and flow-as clinical tools for treating patients.

In vivo demonstration of an antithrombin effect of abciximab.

Abciximab prolonged the activated clotting time (ACT) in a post hoc analysis from the Evaluation of IIb/IIIa Platelet Receptor Antagonist 7E3 in Preventing Ischemic Complications trial and an in vitro study has suggested an antithrombin effect of platelet glycoprotein IIb/IIIa inhibition. The purpose of this study was to evaluate the in vivo effects of abciximab on ACT and thrombin generation. In 46 patients undergoing coronary intervention, 24 received heparin and abciximab (group I), whereas 22 received heparin alone (group II).

Serial angiographic assessment of coronary artery obstruction and collateral flow in acute myocardial infarction. Report from the second Mount Sinai-New York University Reperfusion Trial.

In the Second Mt. Sinai-New York University Reperfusion Trial, in which change of ejection fraction was the primary end point, the following secondary end points were prospectively assessed by serial coronary angiography: patency of the infarct artery both before intervention and 10-14 days later, acute and delayed recanalization rates, presence or absence of collateral flow, and complication rates of acute interventional catheterization. We assigned 393 patients randomly to groups receiving acute cardiac catheterization and a double-blind intracoronary infusion of streptokinase (SK arm), both streptokinase and nitroglycerin (SK-NTG arm), nitroglycerin alone (NTG arm), or conventional therapy without acute catheterization (control arm).

Late thrombolytic therapy preserves left ventricular function in patients with collateralized total coronary occlusion: primary end point findings of the Second Mount Sinai-New York University Reperfusion Trial.

The change in left ventricular ejection fraction from preintervention to predischarge was prospectively assessed in 393 patients with acute myocardial infarction. Within 12 h of symptom onset (mean 6.3 +/- 2.

Determinants of collateral filling observed during sudden controlled coronary artery occlusion in human subjects.

Higher grades of collateral circulation limit the extent of myocardial ischemia observed during balloon inflation in patients with single vessel coronary disease undergoing coronary angioplasty. However, the grade of collateral filling during sudden coronary occlusion varies from patient to patient. To assess which characteristics may predict a high grade of collateral filling, baseline clinical and angiographic variables were correlated with the grade of filling during coronary occlusion in 67 patients (whose angina ranged from 1 week to 36 months in duration) undergoing left anterior descending or right coronary artery angioplasty.

Determinants and protective potential of coronary arterial collaterals as assessed by an angioplasty model.

Two indexes of collateral blood flow, the ratio of distal coronary occlusion pressure/aortic pressure (DCOP/Pao) and angiographic collateral class were determined during elective angioplasty in 36 patients with normal left ventricular function. The association between collateral indexes and 8 anatomic and clinical variables was assessed. A reduction in luminal diameter by greater than or equal to 70% predicted angiographically demonstrable collaterals with 100% specificity and 85% sensitivity.

Prospective analysis of electrocardiographic variables as markers for extent and location of acute wall motion abnormalities observed during coronary angioplasty in human subjects.

To assess the usefulness of different electrocardiographic variables as markers for the presence, extent and location of new wall motion abnormalities seen after sudden controlled coronary occlusion, 23 patients with isolated left anterior descending (n = 12), or right (n = 11) coronary artery disease and a normal baseline left ventriculogram were prospectively studied during transluminal coronary angioplasty. A simultaneous 12 lead electrocardiogram was recorded before passing the balloon catheter and again at 30 seconds into the fourth inflation cycle. Using a second arterial catheter, a left ventriculogram was obtained at 40 seconds into the fourth inflation cycle.

Limitation of myocardial ischemia by collateral circulation during sudden controlled coronary artery occlusion in human subjects: a prospective study.

We have shown improvement in collateral filling immediately after sudden controlled coronary occlusion in human subjects undergoing elective coronary angioplasty. It has been suggested but not proved that collateral circulation can limit myocardial ischemia. We prospectively studied 23 patients with isolated left anterior descending (n = 14) or right coronary (n = 9) disease and normal left ventriculograms during elective coronary angioplasty.

Coronary angiographic morphology in myocardial infarction: a link between the pathogenesis of unstable angina and myocardial infarction.

It has previously been shown that analysis of coronary morphology can separate unstable from stable angina. An eccentric stenosis with a narrow neck or irregular borders, or both, is very common in patients who present with acute unstable angina, whereas it is rare in patients with stable angina. To extend these observations to myocardial infarction, the coronary morphology of 41 patients with acute or recent infarction and nontotally occluded infarct vessels was studied.

Long-term follow-up after intracoronary streptokinase therapy for acute myocardial infarction.

This article describes the effects on patients treated with intracoronary streptokinase during acute myocardial infarction and long-term follow-up. The mortality and the incidence of cardiac events were assessed during a follow-up period of 35 +/- 5 months. Coronary artery bypass grafting was undertaken in 37% of the patients.

Prevalence and significance of residual flow to the infarct zone during the acute phase of myocardial infarction.

Residual flow to the infarct zone was assessed by coronary angiography during the acute phase of myocardial infarction in 130 patients. In 36 patients, the infarct-related coronary artery was not completely obstructed, thereby providing residual anterograde flow to the infarct area (Group I). Complete obstruction of the infarct vessel with residual flow to the infarct zone by means of collateral circulation was observed in 56 patients (Group II).

[Relation between electrocardiography and coronary angiography findings in the infarct stage].

One hundred and fifty-two patients underwent cardiac catheterization and coronary arteriography within 6.3 +/- 6.0 hours from onset of acute myocardial infarction.

[Significance of precordial ST segment depressions in acute inferior infarct--correlation with coronary angiography and ventriculography findings in the acute infarct phase].

Thirty-two patients presenting with acute transmural inferior wall myocardial infarction underwent cardiac catheterization and angiography within 12 hours of onset of symptoms. Twelve lead electrocardiograms performed within 11/2 hours of catheterization revealed the following: Seventeen patients exhibited ST-segment depression in the anterior precordial leads in addition to inferior wall changes (group A). Fifteen patients did not manifest any ST-segment changes in the anterior precordial leads (group B).

Changes in collateral channel filling immediately after controlled coronary artery occlusion by an angioplasty balloon in human subjects.

Transluminal coronary angioplasty can serve as a model for controlled coronary artery occlusion and reperfusion which enables assessment of short-term changes in collateral vessel filling in patients with severe atherosclerotic coronary artery disease. In 16 patients with isolated left anterior descending or right coronary artery disease (greater than or equal to 75% stenosis) and normal left ventricular function, collateral filling to the artery being dilated was visualized by contrast injection into the contralateral artery using a second arterial catheter. During balloon inflation, contralateral dye injection was performed as soon as the patient developed angina or ST-T changes or at 90 seconds in those patients without symptoms or signs of ischemia.

Thrombolytic therapy in acute myocardial infarction: review of clinical trials.

Intracoronary infusion of streptokinase is associated with recanalization rates of 60 to 90% immediately after the procedure. Mortality data in published trials are conflicting. In 125 registry patients who had paired contrast ventriculograms before streptokinase infusion and hospital discharge, improvement in ejection fraction correlated with incomplete coronary obstruction before angiography, the presence of collateral vessels to the infarct area and recanalization of complete obstruction.

Effects of intracoronary streptokinase and intracoronary nitroglycerin infusion on coronary angiographic patterns and mortality in patients with acute myocardial infarction.

We randomly assigned patients with a clinical diagnosis of acute myocardial infarction to one of four treatment groups: intracoronary streptokinase, intracoronary nitroglycerin, intracoronary streptokinase and intracoronary nitroglycerin, or conventional therapy without initial angiography. Of 124 patients 122 sustained acute myocardial infarction. Initial angiography revealed total occlusion of the coronary artery responsible for infarction in 67 per cent (61 of 91).