[Problems of aortocoronary bypass. Indications for coronary angiography and ventriculography; results of direct bypassing coronary surgery].

The introduction of selective coronary arteriography and aorto-to-coronary saphenous vein bypass surgery (a.-c bypass) has fundamentally altered our understanding of ischemic heart disease (IHD). The indications for the effective diagnostic procedure and the results of the new and increasingly important surgical technique are summarized. Selective coronary arteriography should be performed (a) in patients with known IHD in order to furnish the anatomical and functional information necessary to assess the indication for surgery, i.e. in patients below 60 years with intractable stable or unstable (impending infarction) angina. It is rarely indicated in patients with an old myocardial infarction who are free from symptoms. It is debatable in patients during the acute stage of infarction; (b) in patients with questionable IHD, with the aim of ruling out or confirming the condition, i.e. mainly in patients with atypical chest pain or with equivocal ecg findings. The risks of the procedure, if carried out by experienced personnel, are small. Selective arteriography will always be supplemented by a selective left ventricular angiography yielding important information concerning the functional behaviour of the myocardium. In judging the therapeutic value of a.-c. bypass surgery it should be noted that postoperatively 60 to 70 percent of the patients present without symptoms and 80 to 95 percent feel markedly better, and that physical performance is enhanced in about the same proportions. An improvement in left ventricular function under exercise conditions seems to be rare. Hospital mortality of a.-c. bypass operation is small and below 5 percent if patients with stable angina and without myocardial failure, previous infarctions or mitral regurgitation are considered. In the presence of an ischemic cardiomyopathy, on the other hand, the mere surgical risk soon reaches prohibitive limits. The incidence of early complicating myocardial infarctions ranges around 10 percent. Bypass occlusion occurs in some 5 to 15 percent during the early postoperative phase, while in the following months and years the patency rate diminishes but little. If the survival rates of operated and non-operated patients with IHD are compared it becomes evident that a prolongation of life is possible whenever surgery aims at a correction of two- and three-vessel disease (including the prognostically unfavourable isolated stenosis of the left anterior descending branch and stenosis of left main artery) whereas the natural course of isolated lesions of the right coronary artery and the left circumflex branch seems to balance the effect of corresponding surgical interventions. It should be borne in mind, however, that the follow-up periods on which these statements are based do not exceed 3-4 years.