Coronary bypass graft fate: long-term angiographic study.

In 222 patients, 741 venous coronary bypass grafts were studied angiographically early, at 1 year and at a late examination at greater than 6.5 years (mean 9.6) after operation; 565 of these grafts were also examined 5 years postoperatively. Grafts were graded for patency and disease considered to be atherosclerotic and for both extent and profile of lesions. Graft occlusion rates increased steadily from 8% early to 20% at 5, 41% at 10 and 45% at greater than 11.5 years after operation. All grafts were considered free of atherosclerosis early, but disease appeared in 8% at 1 year, increasing to 38% at 5 and 75% at 10 years postoperatively. Increasing involvement of vessel wall area was associated with greater protrusion of lesions into the graft lumen. Diseased grafts became more so at subsequent examinations, with occlusion occurring in many. However, absence of disease had little prognostic significance because diseased and abruptly occluded grafts were generated in those with healthy appearance at earlier examinations. For instance, 82% of very diseased grafts at the 5 year study originated from normal grafts at 1 year and 73% of occluded grafts at 1 year had appeared normal early postoperatively. Of 590 patent grafts free of disease at 1 year, 30% were occluded at the late examination, 76% of those patent were diseased, 55% of these were diffusely diseased and 35% were greater than 50% narrowed. Only 17% of the original 590 patent grafts were healthy at this time. Bypass graft atherosclerosis severely limits the long-term utility of these grafts. It is suggested that the solution may lie in some powerful drug regimen.

Coronary artery disease and coronary bypass grafting in young men: experience with 138 subjects 39 years of age and younger.

One hundred thirty-eight men aged less than or equal to 39 years had coronary bypass grafting during a 13 year period. Angina was the presenting symptom in 77% and of these patients, one-third had unstable angina. More than half of the patients had experienced at least one myocardial infarct. There was a high incidence of coronary risk factors, especially smoking. Nineteen patients (13.8%) had left main coronary artery stenosis (it was isolated in two); 13.8, 24.6 and 60.2% had single, double and triple vessel disease, respectively. Left ventriculograms showed serious functional impairment in 42%. A total of 461 coronary bypass grafts, 3.34 per patient, were placed; almost all were vein grafts. There were no operative deaths. Transmural myocardial infarction occurred in 4.3% of patients. All bypass grafts were opacified angiographically early after operation, 95% at 1 year, 56% at 5 years and 26% at 10 years after operation. Some patients also had coronary angiograms, dictated by clinical events, between 1 and 5 and between 5 and 10 years postoperatively. Patency rates for bypass grafts were comparable with those previously reported and were acceptable, although they decreased with time. However, increasing evidence of atherosclerosis of bypass grafts was seen beyond 1 year, particularly beyond 5 years. Of 23 subjects with a coronary bypass reoperation, 2 died and 44% had perioperative transmural myocardial infarction. During follow-up, 13.8% of the patients died, survival being 95, 84 and 76% at 5, 10 and 12 years, respectively. It is considered that the patients were advantageously treated with coronary bypass grafting especially in the short-term. However, bypass graft patency steadily decreased with the passage of time and graft atherosclerosis became an increasingly important problem.

Coronary bypass graft fate and patient outcome: angiographic follow-up of 5,065 grafts related to survival and reoperation in 1,388 patients during 25 years.

OBJECTIVES: We sought to examine, angiographically, the longterm fate of a large number of mainly venous coronary bypass grafts and to correlate graft patency and disease with patient survival and reoperation. BACKGROUND: Much is known about bypass graft patency and disease, but the precise relation between graft fate and patient outcome has not been substantiated and documented. METHODS: A total of 1,388 patients underwent a first coronary artery bypass graft procedure at a mean age of 48.9 years, 234 had a second bypass procedure at a mean age of 53.3 years, and 15 had a third bypass procedure at a mean age of 58.2 years during the 25-year period from 1969 to 1994. Most were male military personnel or veterans; 12% were < or = 39 years old. Of 5,284 grafts placed, 91% were venous and 9% arterial. Angiograms were performed on 5,065 (98% of surviving) grafts early, on 3,993 grafts at 1 year and on 1,978 grafts at 5 years after operation; other examinations were also performed up to 22.5 years after operation, and 353 grafts were examined after > or = 15 years. Grafts were graded for patency and disease. The status of all patients was known at the study's end. RESULTS: The perioperative mortality rate was 1.4% for an isolated first coronary bypass procedure, 6.6% for reoperation. Vein graft patency was 88% early, 81% at 1 year, 75% at 5 years and 50% at > or = 15 years; when suboptimal grafts, graded B, were excluded from calculation, the proportion of excellent grafts, graded A, decreased to 40% after > or = 12.5 years. After the early study, the vein graft occlusion rate was 2.1%/year. Internal mammary artery graft patency was significantly better but decreased with time. Vein graft disease appeared by 1 year and the rate accelerated by > or = 2.5 years, involving 48% of grafts at 5 years and 81% at > or = 15 years; 44% of the latter grafts were narrowed > 50%. Survival of all patients was 93.6% at 5 years. 81.1% at 10 years, 62.1% at 15 years, 46.7% (150 patients) at 20 years and 38.4% (25 patients) at 23 years after operation. Survival decreased as age increased, but curves approximated "normal" life expectancy for older patients. Survival curves at all ages showed a steeper decline after 7 years. The rate of reoperation increased between 5 years and 10 to 14 years, then decreased to stable levels. Coronary atheroembolism from vein grafts was the major cause of morbidity and mortality associated with reoperation. Vein graft patency and disease were temporally and closely related to reoperation and survival. CONCLUSIONS: Coronary bypass graft disease and occlusion are common after coronary artery bypass grafting and increase with time. They are major determinants of clinical prognosis, specifically measured by reoperation rate and survival. Intraoperative graft atheroembolism was a major reoperation hazard. Reoperation is definitely worthwhile but entails identifiable risks that must be dealt with.

Coronary bypass graft fate. Angiographic study of 1,179 vein grafts early, one year, and five years after operation.

A total of 1,179 vein grafts were studied angiographically in 353 (45%) unselected survivors (male, mean age 45.5 years) of 786 coronary bypass operations. Studies were conducted early (0.96 months), 1 year (12.8 months), and 5 years (59.7 months) postoperatively. A previously described technique was used to grade the patency of the grafts, and a new technique was used to assess intimal irregularity, presumably caused by atherosclerosis; this new technique indicated both intimal surface distribution of disease and profile (relief or elevation). Ten percent, 17%, and 26% of grafts were occluded early, at 1 year, and at 5 years, respectively. Distal anastomotic defects were the commonest cause for low grades in the patency classification. Irregularities in patent grafts increased from 9% at 1 year to 42% at 5 years, with 11% of all the 1 year lesions and 20% of all the 5 year lesions having a high profile (more than 50% graft stenosis); of the lesions categorized as showing the widest surface spread, 17% were in high relief at 1 year and 34% at 5 years. Thus, the lesions we believed to be atherosclerotic proliferated in both surface spread and elevation. All severely diseased grafts at the 1 year study had been normal in outline early; 79% at the 5 year study had been disease free at 1 year. All newly occluded grafts at the 1 year study had been normal in outline and 82% had had good patency early; 78% of newly occluded grafts at the 5 year study had been disease free at 1 year and 77% had had good patency. Normal appearance of the intima in grafts studied at 1 year had no prognostic value for 5 year findings. However, 62% of all grafts with the appearance of intimal disease at 1 year showed deterioration by 5 years, and 28% were occluded. The differences between these outcomes are highly significant (p less than 0.0005). In conclusion, the appearance of intimal irregularity compatible with atherosclerosis in a coronary bypass graft 1 year after operation carried a poor prognosis for adverse angiographic change at 5 years. On the other hand, normally appearing intima at 1 year had no predictive valve for the 5 year study despite a generally better prognosis for nondiseased grafts.

Interventions for coronary stenosis--a Canadian experience of 30 revolutionary years.

OBJECTIVE: To report 2324 coronary stenosis interventions (Vineberg procedures [VbP], coronary artery bypass graft operations [CABG] and percutaneous transluminal coronary angioplasties [PTCA]), in 1711 patients of a Canadian military hospital between 1965 and 1995 and to report their evolution and interaction in a historical context. DESIGN: Retrospective examination of clinical and angiographic findings in hard records, collected from the beginning for long term follow-up and later embedded in a custom-designed computer database. PATIENTS: Most were male, mean ages 43.2 and 43.3 years for first and second VbPs; 48.9 and 58.2 years for first and repeat CABGs; and 53.4 and 59.9 years for first and repeat PTCAs, respectively; 12% of all patients were 39 years old or younger at the first intervention. INTERVENTIONS: There were 160 VbPs, 1637 CABGs and 527 PTCAs. Of 1711 subjects, 74% had only one procedure, 15% had more than one of the same kind, and 11% had more than one of different kinds. MAIN RESULTS: Perioperative mortality for VbPs was 4.4%; for 'isolated' first CABGs it was 1.4% and 6.6% for reoperations, when other concurrent major cardiac procedures, excepting ventricular aneurysm repair, were excluded. It was 0.4% for PTCAs. Perioperative mortality for all 1761 'isolated' coronary interventions necessitating thoracotomy, during 30 years, was 2.4%. Angiographic follow-up rates were high and some findings are reported, including early postoperative patency rates for 5065 coronary bypass grafts, and long term follow-up data on graft patency and disease. CONCLUSIONS: Each intervention was used to circumvent or relieve coronary stenosis, in the early years when it became available and, later, as was most appropriate for dealing with specific clinical problems. The impact of advances in the evolution of these interventions on therapeutic decision-making is discussed. Finally, tributes are paid to those responsible for making these procedures possible, including a Canadian surgeon whose role was pivotal.

Atherosclerosis of coronary artery bypass grafts and smoking.

Follow-up angiography was performed at selected intervals on 340 men who had undergone coronary artery bypass surgery. There were 1160 grafts, but 112 were excluded from study because they occluded shortly after the operation. After 5 years 115 patients were smokers and 225 were nonsmokers. The mean number of grafts per patient was similar in the two groups. We classified each graft according to irregularities in graft outlines and graft patency and found disease-free grafts in 39% of the smokers and 52% of the nonsmokers; the proportion of diseased or occluded grafts was greater in the smokers than in the nonsmokers. Our results do not identify the effect of smoking cessation after bypass surgery, but they do suggest that men who continue to smoke are at significantly greater risk of atherosclerosis and occlusion than nonsmoking men.