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Nineteen pigs were studied in order to assess the effect of low grade, radiofrequency-powered, thermal balloon angioplasty on the vasoconstrictor response of peripheral arteries. A mechanical stimulus was used to induce vasospasm. Thermal angioplasty reduced the extent of inducible vasospasm from 79% to 6% compared to nonthermal control inflations, which reduced the vasoconstrictor response from 75% to 60% (P < 0.001). Histologic studies demonstrated that the extent of myocyte necrosis was significantly greater in the thermally treated arteries than in the control vessels (P < 0.01). Thermal balloon angioplasty at 60 degrees C significantly attenuates peripheral arterial vasospasm induced by mechanical trauma in the porcine model. This paralytic effect may be related to the loss of myocytes secondary to thermal necrosis.

The purpose of this study was to assess the efficacy of local heparin delivery to balloon angioplasty sites in an in vivo porcine model by using a newly designed angiotherapy catheter that allows for prolonged drug infusion while maintaining distal arterial perfusion. Protocols were designed to assess the safety of intracoronary drug delivery, the effect of infusion time and drug concentration on intramural heparin deposition, the distribution of heparin within the arterial wall, the histologic effects of local heparin delivery, the wash-out of intramurally deposited heparin, and the effect of heparin delivery on early platelet deposition following balloon injury in peripheral and coronary vessels. Local intracoronary delivery of heparin was well tolerated in all animals. Between 0.04 and 0.08% of infused heparin was intramurally deposited at the time of drug delivery, with longer infusion durations and higher concentrations of heparin resulting in greater intramural deposition. Autoradiography demonstrated homogenous distribution of heparin throughout the intima, media, and adventitia, with localization in the nuclei, cytoplasm, and extracellular space. Histologic analysis demonstrated no additional vessel trauma from local drug delivery beyond that seen with conventional angioplasty. Wash-out studies demonstrated a biexponential disappearance of intramurally deposited drug, with rapid release of heparin over the first 60 min and persistence of small amounts of drug for at least 7 d. Locally delivered heparin significantly attenuated the deposition of platelets in peripheral vessels, although a similar decrease in platelet deposition in the coronary arteries was not statistically significant. Local delivery of heparin directly to coronary angioplasty sites is possible with the use of a new angiotherapy catheter. Wash-out of heparin from the arterial wall is initially rapid, although drug is detectable for up to 1 wk following delivery. In porcine peripheral arteries, use of this technique significantly decreases early platelet deposition following balloon injury.

Intraluminal delivery of antisense oligonucleotides to c-myb was assessed following balloon angioplasty in swine peripheral arteries. Successful delivery and intramural persistence of oligonucleotide for over 24 h were demonstrated following angioplasty with hydrogel balloons coated with 32P-labeled antisense. Delivery of fluorescein-labeled antisense demonstrated further localization within the arterial media and intracellularly. Preliminary in vitro studies demonstrated the feasibility of inhibition of porcine lymphocyte proliferation using the murine antisense to c-myb. Twelve iliac or carotid arteries underwent angioplasty with antisense-coated balloons, while the contralateral vessels underwent angioplasty with the same-sized balloons coated with the complementary sense strand. Six to seven days later, dilated arterial segments were surgically isolated. In 10 of 12 vessel pairs, antisense-treated vessels demonstrated less cellular proliferation than did contralateral sense-treated vessels, as assessed by quantitative immunohistochemical staining of proliferating cell nuclear antigen, and smooth muscle cell proliferation was reduced 18% in antisense-treated vessels compared to the contralateral sense-treated vessels (PCNA-positive nuclear area: 7.7 +/- 4.9% vs. 9.3 +/- 5.2%, P < 0.04)-intraluminal delivery of antisense oligonucleotides to c-myb is feasible with a catheter-based system and may reduce smooth muscle cell proliferation following arterial injury.

Current techniques for the percutaneous revascularization of totally occluded vein grafts are limited by a low initial success rate, a significant incidence of distal embolization, and a high rate of early graft reclosure. This case report describes two patients in whom graft recanalization was attempted with the combined use of balloon angioplasty/intra-graft stent placement and local urokinase delivery using a new angiotherapy catheter. Successful recanalization was achieved in both patients without major complications, in spite of a large thrombus burden as demonstrated by angiography.

A 38-year-old multigravid white female presented at 16 weeks gestation with an acute inferoposterolateral myocardial infarction. Emergent coronary angiography demonstrated a total proximal occlusion of a large dominant left circumflex artery with a filling defect at the site of the occlusion suggestive of thrombus. Primary angioplasty using a urokinase-coated hydrogel balloon resulted in successful recanalization of the vessel with restoration of normal TIMI Grade III flow and, most notably, apparent complete lysis of the intracoronary thrombus. After a subsequently uneventful pregnancy, a healthy baby was delivered.

Background: The presence of intracoronary thrombus significantly increases the risk of conventional balloon angioplasty because of a high incidence of abrupt closure, distal embolization, and no-reflow phenomenon. The purpose of this study was to assess a new technique for treating intracoronary thrombus consisting of the local delivery of urokinase directly to the angioplasty site with a novel, catheter-based, drug delivery system., Methods: The Dispatch catheter is a new local, drug-delivery device that allows for the prolonged infusion of therapeutic agents at an angioplasty site while still maintaining distal coronary perfusion. Six patients with angiographic or clinical evidence of intracoronary thrombus were treated with 150,000 units of urokinase over a 30-min period using this device prior to or following conventional balloon angioplasty and/or directional atherectomy., Results: Successful delivery of urokinase directly to the angioplasty site was achieved in all 6 patients without hemodynamic or electrocardiographic compromise. In all six cases, local urokinase therapy resulted in complete dissolution of angiographic intracoronary thrombus and/or reduction of the coronary stenosis. Limited ischemia due to side-branch occlusion by the catheter's coils was noted in one patient. Distal embolization or no-reflow phenomenon were not observed in any case., Conclusion: The local drug-delivery catheter used in this study was able to successfully and rapidly achieve intracoronary thrombolysis by delivering limited quantities of urokinase directly to the angioplasty site, while still maintaining distal coronary perfusion. This technique of local, thrombolytic drug delivery may be useful in the percutaneous treatment of intracoronary thrombus and thrombus-containing stenoses.

A patient with Prinzmetal angina and ST segment elevation in the anterior ECG leads became asymptomatic after a 50% left anterior descending coronary artery stenosis was bypassed. However, seven years later Prinzmetal angina recurred but with ST segment elevation in the inferior ECG leads. Although the coronary bypass graft had remained patent, the proximal and distal left anterior descending coronary artery was occluded. No significant stenosis was present in the right coronary artery. Perhexiline maleate controlled his symptoms but when the drug was stopped because of side effects an acute inferior myocardial infarction occurred.

A young man with a single left coronary artery and refractory variant angina is described. Spontaneous coronary artery spasm developed during coronary arteriography at the site of a 50% fixed left anterior descending coronary artery stenosis. Frequent episodes of rest angina with transient ST segment elevation persisted in hospital in spite of treatment with three different calcium antagonist drugs. Symptoms disappeared only when the combination of nifedipine, diltiazem, isosorbide dinitrate, and nitroglycerin ointment were given. Ergonovine testing was used to objectively assess the response to treatment.

This report describes a 70-year-old woman with biventricular failure following an anteroseptal infarction complicated by interventricular septal rupture. Treatment with nitroprusside followed by oral hydralazine eliminated the failure and reduced the shunt from 2.75 to 1 to 1.7 to 1. She is asymptomatic post-discharge. Chronic medical therapy including oral vasodilators may be an acceptable alternative to surgery in a small minority of patients with this complication of myocardial infarction.