IDENTIFICATION OF PATIENTS AT HIGH-RISK FOR ADVERSE CORONARY EVENTS WHILE AWAITING ROUTINE CORONARY ANGIOPLASTY

Background-Identification of patients at risk for progression of coron ary stenosis and adverse clinical events while awaiting coronary angio plasty is desirable. Objective-To determine the standard clinical or a ngiographic variables, or both, present at initial angiography associa ted with the development of adverse coronary events (unstable angina, myocardial infarction, and angiographic total coronary occlusion) in p atients awaiting routine percutaneous transluminal coronary angioplast y (PTCA). Patients and methods-Consecutive male patients on a waiting list for routine PTCA. Routine clinical details were obtained at initi al angiography. Stenosis severity was measured using computerised angi ography. Outcome measures-Development of one or more of myocardial inf arction, unstable angina, or angiographic total coronary occlusion whi le awaiting PTCA were recorded as an adverse event. Results-Some 214 o f 219 patients underwent a second angiogram. One had a fatal myocardia l infarction and four (2%) were lost to follow up. Fifty patients (23% ) developed one or more adverse events (myocardial infarction five, un stable angina 35, total coronary occlusion 23) at a median (range) int erval of 8 (3-25) months. Twenty (57%) of the 35 patients with unstabl e angina developed adverse events compared with 30 (17%) of the 180 wi th stable angina (P = 0.0001). Plasma triglyceride concentration was 2 .6 (1.2) mmol/l in patients with adverse coronary events compared with 2.2 (1.1) mmol/l in those without such events (P < 0.05). Patients wi th adverse events were younger than those without (54 (9) years v 58 ( 9) years, P < 0.01). The relative risk of an adverse event in patients with unstable angina and increased plasma triglyceride concentrations was 6.9 compared with those presenting with stable angina and a norma l triglyceride concentration (P < 0.02). Conclusions-The study shows t hat adverse events are not uncommon in patients awaiting PTCA. Patient s at high risk for adverse events may be predicted by the presence of acute coronary syndrome, increased concentration of plasma triglycerid e, and younger age at the time of the first angiogram.