The effect of porous infusion balloon-delivered angiopeptin on myointimal hyperplasia after balloon injury in the rabbit.

BACKGROUND: Angiopeptin, a synthetic somatostatin analogue, reduces myointimal hyperplasia after experimental balloon angioplasty when given subcutaneously. The feasibility and efficacy of a single dose of angiopeptin delivered locally via the Wolinsky porous balloon on myointimal hyperplasia were studied. METHODS AND RESULTS: Three rabbits received 125I-angiopeptin in the mid abdominal aorta via the Wolinsky balloon at 5 atm for 1 minute after balloon injury. Thirty minutes later, autoradiography demonstrated radioactivity in the media and the adventitia. Forty rabbits were divided equally into one control group receiving saline and three angiopeptin groups receiving 1, 10, or 100 micrograms/mL of angiopeptin delivered locally at 5 atm for 1 minute via the Wolinsky balloon into the mid abdominal aorta after balloon injury of the entire abdominal aorta. On day 21, the abdominal aortas were fixed in situ and harvested. There was no statistical difference in the amount of myointimal hyperplasia in the locally treated aorta in the angiopeptin groups compared with the control group. However, in the lower abdominal aorta, where balloon injury without local delivery was performed, there was a significant reduction of myointimal hyperplasia in the highest-concentration angiopeptin group (P < .001 versus the control group). Electron microscopy showed that the control animals had a pseudointima of smooth muscle cells throughout the aorta, whereas in all the angiopeptin-treated animals, endothelial cells were present at both locations. CONCLUSIONS: Angiopeptin can be delivered intramurally via the Wolinsky porous balloon and reduces myointimal hyperplasia only in the area distal to the local drug delivery site (downstream effect), possibly by healing the injured endothelium, by transport via the vasa vasora, and/or by systemic effect.

Reduction of myocardial infarction after emergency coronary artery bypass grafting for failed coronary angioplasty with use of a normothermic reperfusion cardioplegia protocol.

Emergency coronary artery bypass grafting is necessary in 2.7% to 13.5% of patients undergoing elective percutaneous transluminal coronary angioplasty. Myocardial infarction develops in 11% to 49% of these patients, with 18% to 46% of infarcts resulting in new Q waves. Since February 1987 a revised protocol for myocardial preservation has been used in 19 patients undergoing emergency bypass grafting for failed angioplasty. Cardioplegia is induced with a normothermic blood cardioplegic solution. Multiple maintenance doses of cold (4 degrees C) blood cardioplegic solution are then delivered through the aortic root and vein grafts. Before the aortic crossclamp is removed, normothermic reperfusion cardioplegic solution is delivered through the aortic root and vein grafts. This group was compared with all patients undergoing emergency bypass grafting for failed angioplasty before February 1987. These 45 patients received cold induction of cardioplegic solution, multiple maintenance doses of cold cardioplegic solution, and no reperfusion cardioplegic solution. The prevalence of myocardial infarction in the group receiving cold cardioplegic solution was 65% versus 26% in the group receiving normothermic cardioplegic solution (p less than 0.007). Multivariate analysis identified the use of the normothermic cardioplegia protocol (p less than 0.005), nontotal occlusion of the angioplasty vessel (p less than 0.03), and presence of collateral flow to the angioplasty vessel (p less than 0.04) as being independently associated with absence of myocardial infarction.

Quantification of ST-segment changes during coronary angioplasty in patients with left bundle branch block.

Electrocardiographic manifestations of ischemia are difficult to interpret in the presence of left bundle branch block (LBBB). Recently developed techniques allow continuous computerized digital analysis of ST segments that can be zeroed to the patient's own baseline electrocardiogram even if that baseline is abnormal conduction. With use of this technology, ST-segment changes during balloon coronary occlusion were compared in 10 patients with LBBB versus an age-, sex-, and coronary anatomy-matched population of 20 control subjects with normal baseline conduction. ST-segment deviation of greater than or equal to 1 mm from baseline was present in 80% of patients with LBBB and in 75% of control patients (difference not significant). There was no significant difference between patients with LBBB versus control patients in maximal ST-segment deviation (2.6 +/- 1.7 vs 2.0 +/- 1.0 mm) or in ST-segment deviation measured after 60 seconds of occlusion (2.4 +/- 1.3 vs 1.8 +/- 1.1 mm). ST-segment deviation reached 1 mm more quickly in patients with LBBB (33 +/- 11 seconds) than in control subjects (60 +/- 36 seconds) (p = 0.003). It is concluded that ST-segment analysis is feasible in patients with LBBB using digital self-referenced ST analysis and may provide important clinical information regarding the presence of myocardial ischemia.

Myocardial salvage after failed coronary angioplasty.

UNLABELLED: Patients undergoing coronary angioplasty have a 2% to 7% risk of requiring emergency coronary artery bypass graft surgery for impending infarction. These patients provide a unique model of early reperfusion because the exact time of compromise to blood flow and the composition of the reperfusion solution are known. However, the amount of myocardium salvaged is unknown. Between December 1981 and September 1985, 859 patients underwent coronary angioplasty. Forty-two patients had emergency surgery for objective evidence of impending infarction. Five patients died. Thirty-six patients were contacted for follow-up; 21 (58%) of 36 had a radionuclide ventriculogram performed at a mean of 39 +/- 13 months after surgery. These radionuclide studies were compared with the patient's preangioplasty contrast ventriculogram. One patient had a myocardial infarction 3 years after surgery. Eleven (55%) of the remaining 20 patients had a normal radionuclide ventriculogram at follow-up study (ejection fraction 65 +/- 9%). Five (25%) of the 20 patients had a depressed ejection fraction (46 +/- 4%) with wall motion abnormalities, but these were unchanged from the preangioplasty studies. Four patients (20%) had a significant decrease in ejection fraction over baseline (37 +/- 10%) with new wall motion abnormalities. IN CONCLUSION: 1) there is an 80% chance that left ventricular function will be unchanged at 3 year follow-up study in patients surviving emergency bypass grafting for failed angioplasty; 2) these data suggest that early revascularization for impending infarction in this setting is associated with a good late outcome; and 3) this patient group offers a unique opportunity to study the effects of early reperfusion in a human model.

Intervention in acute myocardial infarction.

The role of thrombolytic therapy in decreasing mortality and improving left ventricular function has been well established. The role of secondary PTCA is still being defined. Current data support a strategy of performing coronary angiography and elective PTCA only in patients with evidence of ischemia after thrombolytic therapy. Despite the trend away from routine early invasive therapy for acute myocardial infarction, accurate definition of coronary anatomy and assessment of left ventricular function will continue to be vital in the management of these patients and provide a continuing challenge for the cardiac radiographer.

Stability of multilead ST-segment "fingerprints" over time after percutaneous transluminal coronary angioplasty and its usefulness in detecting reocclusion.

Multilead ST-segment recordings taken during percutaneous transluminal coronary angioplasty (PTCA) could function as an individualized noninvasive template or "fingerprint," useful in evaluating transient ischemic episodes after leaving the catheterization laboratory. To evaluate the reproducibility of such ST-segment patterns over time, these changes were analyzed in patients grouped according to the time between occlusion and reocclusion. For the patients in group 1, the study required comparing their "fingerprints" in repeat balloon inflation during PTCA (reocclusion in less than 1 hour), for those in group 2, comparing ST "fingerprints" during PTCA with ST changes during spontaneous early myocardial infarction (reocclusion in 24 hours) and in group 3, comparing ST "fingerprints" with ST changes during repeat PTCA for restenosis greater than 1 month after the initial PTCA. The ST "fingerprints" among the 20 patients in group 1 were identical in 14 cases (70%) and clearly related in another 4 (20%). Of the 23 patients in group 2, 12 (52%) had the same and 8 (35%) had related patterns. Of 19 patients in group 3, 8 (42% had the same pattern and 8 (42%) had related patterns. Thus, ST fingerprints were the same or clearly related with reocclusion in the same patient from less than 1 hour to greater than 1 month after initial occlusion in 87% of patients overall, in 90% in less than 1 hour, in 87% in less than 24 hours and in 84% greater than 1 month later. Multilead pattern ST-segment "fingerprints" may serve as a noninvasive marker for detecting site-specific reocclusion.

Quantitative ST-segment recovery following angiographically successful angioplasty: a useful warning of early complications.

The angiographic/anatomic appearance of the TCA site and transstenotic gradient trending are two available intraprocedural variables that help to identify patients at high risk for early complications after successful angioplasty. We have reported on an additional variable, the rate of ST recovery following the final balloon deflation as a physiologic marker to identify patients at risk for early complications. Slow ST recovery was present in 52% of patients with early complications of myocardial infarction, urgent or emergent coronary bypass surgery, and/or death, whereas normal ST recovery was seen in 97% of patients with uncomplicated courses. ST trending is a non-invasive modality that is available in all patients undergoing TCA and should be a useful adjunct in identifying patients at high and low risk for early major complications following angiographically successful angioplasty. A prospective study of ST recovery during TCA deserves consideration.