Coronary angioplasty in patients who were considered poor bypass surgery candidates.

In most patients who undergo coronary angioplasty (PTCA), coronary bypass surgery (CABG) is an alternative. Patients with severe symptoms secondary to coronary disease, amenable to PTCA, but who are poor CABG candidates are commonly seen. From April 1988 to December 1989 PTCA was performed in 751 patients. Patients with evolving infarction (47) were excluded. Of the remaining 704, 605 were considered candidates for CABG and they were compared to the 99 patients not felt to be candidates for CABG. The objective of this report was to compare these 2 patient groups. These salvage PTCA patients were older, had a higher incidence of heart failure, more prior CABG, higher left ventricular end-diastolic pressure and lower ejection fraction (all p less than 0.01). PTCA had a high success rate per lesion in both groups (96% CABG candidates vs. 95% salvage patients), but there were more patients whose culprit lesion could not be dilated in the salvage group (14% vs. 7%, p less than 0.02). Severe complications including Q wave infarction (2% vs. .3%) and in-hospital death (7% vs. 0.2%) were more common in salvage patients. As planned, emergency CABG was not performed on any salvage PTCA patient but on 2.6% of the other patients. Patients who may benefit from PTCA but were not felt to be operable made up 13% of our PTCA experience. PTCA can be performed in these patients but risks were increased.

Influence of scar on left ventricular performance at the onset of myocardial ischemia: shock versus heart failure.

Obstruction of a major branch of the left coronary artery in a previously normal ventricle is not usually associated with shock, experimentally or clinically. To examine the early hemodynamic alterations which may determine the course of ischemia when myocardial scar exists from previous infarction, 16 animals were successfully studied 9 wk after obstruction of the left circumflex artery. Acute ischemia during thrombus formation in the anterior descending artery of intact anesthetized dogs with scar was compared with animals undergoing the same procedure in the absence of scar (group 1). In the chronic animals, two types of hemodynamic responses were observed. Group 2 was characterized by heart failure usually persisting through 3 hr, and group 3 by a different ventricular volume response and rapidly developing shock. The weight of ischemic and scar areas were comparable and coronary blood flow ((85)Kr method) to the ischemic site was reduced to a similar extent. Animals in groups 1 and 2 remained normotensive and had similar elevations of left ventricular enddiastolic volume (indicator dilution method) during the initial 60 min of ischemia. Group 2 had a significantly larger rise of end-diastolic pressure, presumably related to altered elastic properties associated with scar of subendocardial distribution. Group 3 had a stroke volume decline that was not significantly greater than group 2 and both groups had an initial rise of peripheral vascular resistance. Despite a nearly fourfold increase of left ventricular end-diastolic pressure, there was a significant decline of left ventricular end-diastolic volume in group 3. This preceded the onset of hypotension in group 3, with arterial pressure declining to a greater extent than stroke volume, usually culminating in cardiac standstill. Group 3 was distinguished by the presence of transmural scar, which was postulated to influence contiguous ischemic tissue in diastole so as to diminish ventricular volume. By analogy with the hemodynamics of acute pericardial tamponade, a reflex pathway activated in the myocardium in response to reduced end-diastolic volume has been suggested as a mechanism for the arterial hypotension.