The angiocardiographic and clinical findings in 218 patients with significant obstruction confined to the left anterior descending coronary artery were reviewed to study the influence of the site of obstruction and of the collateral circulation on clinical presentation and prognosis. One hundred and fifty-six patients had been managed medically, 51 had had aortocoronary bypass operations, and 11 had had left ventricular aneurysms excised. The artery was divided into three segments: left anterior descending 1 (LAD1) from its origin to the first septal branch, left anterior descending 2 (LAD2) from the first septal to the first diagonal branch, and left anterior descending 3 (LAD3) the remaining distal vessel. Cardiogenic shock occurred only in patients with LAD1 lesions, but apart from this the clinical presentation bore no consistent relation to the site of disease. Patients with proximal lesions were more likely to have a "positive" exercise test, had more severely impaired left ventricular function, and had a worse prognosis than those with more distal disease. Non-visualisation of collateral vessels in patients with left anterior descending occlusion was associated with extensive infarction, and patients who presented with infarction had more severely impaired ventricular function than those who presented with angina and subsequently had an infarction. Left ventricular function was poor at the time of angiography in 11 of 12 of those who subsequently died; it is therefore unlikely that the prognosis of patients with isolated left anterior descending obstruction could be improved by expanding the indication for aortocoronary bypass from that of severe angina.

SUMMARY In 60 consecutive patients undergoing vein graft surgery the angiographic appearances of the coronary vessels were compared with those of the vessels at operation. On the basis of lumen diameter at the potential sites for grafting it was possible to predict with reasonable accuracy from examination of the angiogram which vessels were large enough to be grafted. Angiographic predictive accuracy was 82% and was similar both for vessels which filled normally and for those which filled by collaterals. The predictive value of the angiographic assessment was similar for branches thought to be too small (predictive value 74%) and for those considered sufficiently large (predictive value 85%) to receive a vein graft.Disease of the vessel walls was found at surgery (66% of coronary branches examined) more frequently than was predicted from the angiographic appearances (33%). Previous necropsy studies have found a high prevalence of coronary atheroma in the population, yet normal angiographic appearances in the coronary arteries are not uncommon in patients undergoing investigation for suspected coronary disease. The present study showed that atheroma may be present in coronary vessels without encroaching into the vessel lumen, so that it is not evident on the angiogram. Coronary atheroma is thus present more often and is more widely distributed in the coronary tree than is indicated by coronary angiography.Postmortem examination of the coronary arteries of patients who have previously undergone coronary angiography during life suggests that atheroma is more extensive than is apparent from the angiogram. ' Although the magnitude of the stenosis estimated at angiography largely correlates with that determined at subsequent necropsy, angiography in life systematically tends to underestimate the degree of stenosis.2-4Patients in these studies may, however, be atypical in that they died of their coronary disease, or after surgical treatment for it, and thus represent the most severe extreme of the spectrum of the disease. We therefore undertook a study to correlate the extent of coronary atheroma with the angiographic appearances during life by examining the coronary vessels during bypass surgery. The study was concerned with the

Forty patients with persistent or recurrent angina after an aortocoronary bypass procedure underwent a second operation. The cause of recurrent angina, defined by angiography, was thought to be isolated graft failure in 13 patients, progression of disease in ungrafted vessels in 4, incomplete revascularisation in 2, and stenoses distal to patent grafts in 1. More than one factor was responsible in 20 patients. There was 1 early postoperative death and 3 perioperative myocardial infarctions. Thirty-four patients have been followed for more than 3 months (4 to 63 months). Of these, 17 had previously bypassed vessels regrafted and 5 are sympton free, 4 have mild angina, and 8 have severe angina. Ten patients had previously ungrafted vessels grafted and 4 are sympton free, 3 have mild angina, 2 have severe angina, and 1 is limited by breathlessness. Seven patients had a combined procedure and 4 are sympton free, 1 has mild angina, and 2 have severe angina. Reoperation can be carried out safely but the results are less satisfactory than for a primary procedure.

Mortality in patients with coronary artery disease is related to its severity. The commonly used classification of 1,2 or 3 vessel disease is relatively insensitive. We have designed a new classification which takes into account site, severity and effect of multiple lesions in the coronary circulation. Data is recorded on Mark Sense computer cards and a coronary index (CI) obtained. We have collected data from 1100 patients and shown correlations of the index with clinical variables, ventricular function and in particular, mortality.

We compared Hexabrix 320 (580 mOsm kg-1) with Conray 420 (2500 mOsm kg-1) for left ventriculography using a prospective randomised double-blind protocol. One hundred consecutive patients with suspected coronary disease were assigned to Hexabrix (52) or Conray (48) for left ventriculography (dose 10 ml m-2 BSA; flow rate 12 ml s-1). Thirteen patients found Hexabrix unpleasant compared with 24 receiving Conray; overall the feelings of warmth and discomfort were less with Hexabrix than Conray (p less than 0.01 and p less than 0.02 respectively). The incidence of nausea, vomiting, and hypersensitivity was similar. Angiographic quality was better with Conray than with Hexabrix (p less than 0.05). Average changes in heart rate and systolic pressure were similar, though there was greater variation in systolic pressure change after Conray (p less than 0.025). End diastolic pressure increased more after Conray than after Hexabrix (p less than 0.05). These slight advantages of Hexabrix over Conray may be valuable in patients requiring multiple angiograms or in those with impaired cardiac function, but do not justify its use for routine angiography.