Conditional probability of multiple coronary graft failure.

To assess the potential capability of using artery-specific factors to predict the success of coronary bypass grafting, we classified each graft according to the type of graft (mammary, single vein, or multiple skip vein), the degree of obstruction in the native coronary artery, and the size of the grafted artery. The mean patency rates for each category of graft were determined by performing early postoperative (mean 6.6 months) arteriograms in 354 patients. We found that mammary arteries gave the best results for every graft category. Skip vein grafts had a higher mean patency rate than single vein grafts for arteries with obstructions between 70% and 90% and lumina less than 2.0 mm in diameter. The results for vein and skip grafts were equivalent for the category with arteries greater than 2.0 mm and obstruction greater than 90%. Vein grafts produced better results than skip grafts for the remaining categories. Patients were classified into subgroups according to the number of actually observed graft failures. The probabilities that specific numbers of grafts would fail were calculated for each patient. These probabilities were based upon the observed patency rates for the category appropriate for each graft and the hypothesis that individual grafts within a patient fail independently. We observed an excess number of patients with no failures or multiple failures than would be expected according to the hypothesis of independent failure and category-specific patency rates. Conversely, there were fewer patients than expected who had single failures. Therefore, we postulate that there may also be global factors which influence early graft patency.

Association between early graft patency and late outcome for patients undergoing artery bypass graft surgery.

For a group of 658 patients who received coronary artery bypass graft surgery, we investigated the correlation between the degree of early (6 months) graft patency and recurrence of anginal symptoms, late myocardial infarction, and postoperative coronary-related death. The patients were grouped according to the number of surgically placed grafts, and each group was further subgrouped on the basis of the number of grafts functioning at the early postsurgical follow-up examination. The patients were observed over a period as long as 13 years. The frequency with which angina returned correlated significantly with the degree of patency within each of the groups (one, two, three, or four grafts); patients with a higher percentage of patent grafts experienced longer periods of freedom from angina. On the average, patients with all of their multiple grafts patent experienced at least 7 more years of symptomatic relief than their counterparts with all grafts occluded. Most surprisingly, the rate of the return of angina for those patients who had all grafts patent and were completely revascularized was independent of the number of diseased vessels or the number of grafts placed. The findings for coronary death and postoperative infarction showed similar trends.

The rehabilitation of coronary surgical patients.

Coronary revascularization has been reported to have failed to effectively rehabilitate working-age patients. This study of 565 patients demonstrates that motivation to return to work is strongly influences by age and educational level. Patients under age 55 are more likely to return to work than are patients over that age, but preoperative job classification does not influence rehabilitation. Although preoperative disability was associated with a slightly lower return-to-work rate (90%) than was the case with patients working preoperatively (97%) preoperative retirement was a strongly negative influence on rehabilitation. In this study, 80% of the patients worked to or beyond retirement age, and duration of work was not influenced by preoperative disability. The salary produced by those patients who were rehabilitated by surgery was four and a half times greater than the total cost of care and disability payments for the entire patient population. The factors which seemed to be the most important in effective rehabilitation were the psychological preparation of patients and their families and the attitude toward rehabilitation expressed by physicians and employers.

Relationship between graft patency, postoperative work status, and symptomatic relief.

In 405 men under the age of 65 requiring coronary bypass, in whom 6 month postoperative arteriograms were performed, we compared graft patency to postoperative work status and recurrent symptoms. We divided the population into subgroups of patients with varying degrees of patency. When these subgroups were tested, no significant dependence was found between the degree of graft patency and the percentages of patients who were working after operation, unless certain subgroups were removed from the population. When relief of angina was examined in the same manner as the postoperative work, we found a significant dependence between the graft patency and the percentage of patients who reported either short or long-term relief of angina in all groups. Because the rate of rehabilitation was high, even in patients with occluded grafts, and because older patients were less likely to return to work than younger patients despite successful revascularization, we conclude that physician emphasis on work rehabilitation and patient age, as well as graft patency, are all important factors which influence postoperative work status.

Changes in left ventricular wall motion after coronary artery bypass surgery: signal or noise?

We evaluated changes in ventricular wall motion after surgery by comparing smoothed, filtered measurements of regional percent shortening (RPS) from right anterior oblique ventriculograms in 37 patients before and after surgery. After surgery there was a significant (p less than 0.05) decrease in the number of regions with hypokinetic wall motion. The distribution of RPS values was also different (p less than 0.005). However, the mean value of RPS for the surgery group as a whole was not significantly altered. These data were contrasted with RPS data from 11 control patients, who were each studied twice but did not have surgical intervention. Similar analysis of the control group did not show any significant change between studies in the number of hypokinetic regions, and the distributions of RPS for the first and second angiograms were not different. We found a 10.3% absolute mean change in repeated measurements of RPS in the control group. We conclude that significant changes occurred after surgery that were not evident in the control group, and the amount of variability in repeated measurements of RPS suggests that analysis should be applied to group rather than individual data.

Impasse at the crossroads: evolution or regulation.

Today, the free enterprise system of health care delivery is being challenged in the United States, where availability and consumption of health services and their cost are epochal. Review of the health care delivery systems of other nations reveals failure of the system when the national medical community has been divided, when government has monopolized the system, and when fee for service has been abandoned. Government intervention in American health care has been increasingly regulatory and promises to extend regulation in the immediate future. The American medical community can respond by unifying, by reducing its contribution to health care costs, and by changing physician behavior. Consumers have the responsibility to eliminate unnecessary utilization and to become more informed buyers of health care and insurance. The fiscal intermediary has the responsibility to provide tailored insurance options that are cost-effective. As informed and unified medical community can be a formidable force in shaping the future of health care in the United States.

Results of direct coronary artery graft reconstruction. A five-year clinical and arteriographic appraisal.

Three hundred thirty-six patients with severe coronary artery disease were operated upon between June, 1969, and December, 1974. All were followed from 1 to 66 months (average, 37 months) with respect to survival and late myocardial infarction. The patients operated upon were compared statistically with a group of unoperated patients, and this evaluation demonstrated significantly better late survival in the surgically treated patients who had double- and triple-vessel disease. Two hundred thirty-six consecutive patients had clinical and late arteriographic reevaluation more than 6 months postoperatively; 78% were asymptomatic. Factors affecting graft patency are reviewed in detail. Late graft patency is determined by preoperative selection of vessels for grafting. Patency is not an index of success for this procedure. Surgical therapy appears to be the treatment of choice for patients with two- three-vessel coronary occlusive disease.

Assessment of ventricular function in coronary artery disease using nitroglycerin and computerized analysis of left ventriculograms.

The ability to predict if abnormalities in regional wall motion are reversible would assist in selecting patients for aortocoronary bypass operation. This study shows that asynergic areas of the ventricle may be reversed by nitroglycerin. Thirty-four asynergic areas in 30 patients with coronary artery disease were studied before and after administration of nitroglycerin. Nineteen patients with previous infarction, diagnostic Q waves in their electrocardiogram, and akinetic areas in the left ventricle had no change in their akinetic areas after nitroglycerin administration. Nine of these patients did show increased motion in other hypokinetic areas of the myocardium. Five of 11 patients with no evidence of previous infarction showed a dramatic improvement in akinetic areas after nitroglycerin, while of the remaining 6, 5 showed mild improvement. This illustrates that recoverable asynergic areas may be recognized by nitroglycerin.