[Occurrence and predictability of progression of high grade coronary vessel stenoses to occlusions].

The aim of this study is to evaluate the incidence and time of occlusions of high-grade coronary stenoses and to discover risk factors for the prediction of impending occlusions. At the time of scheduled angioplasty, on average within 4.5 months of the first diagnostic angiogram, 35 (6.5% of 650) vessels were already occluded. Another 5 patients had died on the waiting list and 2 had suffered a non-fatal infarction. In comparison to patients without progression of stenoses of a similar location and severity, special risk for the occurrence of occlusions was found in cases with collaterals, after infarctions (history, ECG, angiogram), and with multivessel disease. The prevalence of atherogenic risk factors was also higher. There are no clear differences between both groups as far as age, sex, nature and duration of symptoms, angiographic morphology of stenoses and waiting time for angioplasty are concerned. The stenotic vessels of the 7 patients who died or suffered infarctions had no collaterals. Thus coronary angioplasty should be performed immediately after the diagnostic angiogram. This leads to an increase in the success rate in patients with impending coronary occlusion. The spontaneous risk, however, of these patients in suffering sudden cardiac death or non-fatal infarction is low. On the other hand acute infarction and sudden death in the group of patients without detectable signs of impending occlusions can only be prevented by shortening the waiting time for angioplasty.