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Biomedical subjects

N T Kouchoukos

Publications and source records attributed to N T Kouchoukos.

At least 127 records · Page 7Linked to original sources
PubMed1982

Detection of myocardial injury after coronary artery bypass grafting using a hypothermic, cardioplegic technique.

Fifty patients undergoing isolated coronary artery bypass grafting procedures using a clear, cold cardioplegic solution, topical hypothermia, and reduced systemic flow for intraoperative myocardial protection were evaluated for myocardial injury by serial plasma creatine kinase-MB isoenzyme (CK-MB) measurements and electrocardiograms. Forty-one (82%) of the patients had three-vessel disease. Preoperative left ventricular contractility determined angiographically was normal in 13 patients (26%), mildly abnormal in 26 (52%), and moderately or severely abnormal in 11 (22%). The number of arteries grafted ranged from 2 to 6 (mean, 3.5). The mean duration of aortic clamping was 38.6 +/- 1.6 minutes. There were no hospital deaths. Enzymatic and electrocardiographic (ECG) evidence of myocardial infarction occurred in 1 patient. Nonspecific ECG changes occurred in 16 patients (32%), and th electrocardiograms were unchanged in the remaining 33 patients (66%). In the 49 patients without ECG evidence of infarction, the mean peak plasma CK-MB value, which occurred 6 hours after the onset of cardiopulmonary bypass, was 7.9 +/- 0.8 IU/L (standard error of the mean) and the mean integrated area 158 +/- 19.5 IU/L X hours. There was no correlation between these CK-MB values and the extent of disease, number of arteries grafted, or the duration of myocardial ischemia. These data document a low incidence of perioperative myocardial injury with this technique, and can serve as a baseline for comparison with other techniques for intraoperative myocardial protection in this setting.

Adult↗
PubMed1982

Employment status after coronary artery bypass surgery.

With a few exceptions, prevailing data on return to work after coronary artery bypass surgery indicate no net gain in employment status for at least several years after the operation. Despite the improved surgical experience and advances in the medical management of postoperative patients, only limited employment benefits occur after surgery, and no gains in work rehabilitation over the past decade have been noted. Several characteristics--preoperative work status, nonwork income, occupation, relief of symptoms, age, perception of health, education and severity of disease--appear to be important for estimating the likelihood of employment after surgery. Other influences, such as attitudes of the family, employers and physicians, undoubtedly alter the probability of return to the work force, but are less well documented. Unless constructive approaches toward work rehabilitation are made, the possibility of return to gainful employment should not be considered an indication for or a necessary consequence of coronary artery bypass surgery.

Age Factors↗
PubMed1982

Unstable angina pectoris: management based on available information.

Several prospective randomized studies of medical or surgical therapy have not shown that either form of management alone is uniformly superior with respect to mortality for unstable angina pectoris. Patients managed medically have a greater incidence of angina pectoris. Earlier studies indicated a higher rate of nonfatal myocardial infarction with urgent surgery. Present management includes hospitalization and early intensive medical therapy with nitrates and, usually, beta-blocking agents. Coronary arteriography is advised within a few days. If the patient has left main coronary artery disease or three-vessel disease, early coronary artery bypass graft surgery within days to a couple of weeks is advised. Otherwise, medical management is advised and elective surgery can be performed if the patient remains symptomatic.

Angina Pectoris↗
PubMed1982

Survival of medically treated patients in the coronary artery surgery study (CASS) registry.

The objective of this study was to evaluate the impact on survival of the anatomic extent of obstructive coronary artery disease and of two measures of left ventricular (LV) performance. This study is based on 20,088 patients without previous coronary artery bypass graft surgery who were enrolled in the registry of the National Heart, Lung, and Blood Institute Coronary Artery Surgery Study from 1975 to 1979. The cumulative 4-year survival of medically managed patients was analyzed to determine the survival of specific subsets of patients with obstructive coronary disease. The vital status of 99.8% of the patients was known. The 4-year survival of medically treated patients with no significant obstructive disease was 97%, in contrast to 92%, 84% and 68% in patients with one-, two- and three-vessel disease, respectively. The presence of left main coronary artery disease decreased survival significantly. The 4-year survival decreased from 70% to 60% in patients with three-vessel disease when significant obstruction of the left main coronary artery was also present. Patients with significant coronary artery disease who had an ejection fraction of 50--100%, 35--49%, and 0--34% had a 4-year survival of 92%, 83% and 58%, respectively. The systolic contraction pattern was assessed in five selected segments and given a score of 1--6, with a score of 1 for normal function, increasing to 6 if an aneurysm was present. In a patient with normal LV contraction in all five segments of the LV ventricular angiogram, the LV score would equal 5. Patients with an LV score of 5--11, 12--16 and 17--30 had 4-year survivals of 90%, 71% and 53%, respectively. Patients with good LV function (a score of 5--11) had a 4-year survival of 94%, 91% and 79% for one-, two- and three-vessel disease, respectively. Patients with poor left ventricular function (score of 17--30) had a 4-year survival rate of 67%, 61% and 42% in one-, two- and three-vessel disease, respectively. Thus, LV function is a more important predictor of survival than the number of diseased vessels.

Coronary Artery Bypass↗
PubMed1982

Costs and benefits associated with treatment for coronary artery disease.

Direct and indirect costs of medical and of surgical treatment are presented for patients entered into the Birmingham portion of the Coronary Artery Surgery Study. For comparison, similar results are shown for the Birmingham portion of the national Cooperative Unstable Angina Study. In the Unstable Angina Study, mean inpatient costs at the end of 1 year in the study were $6867 for medical therapy, $10,574 for surgical therapy and $23,045 for those who failed medical therapy and required late surgery. A stepwise multiple regression analysis shows that the single best predictor of cost was the number of myocardial infarctions that the patient had while in the study. A discriminant-function analysis identified 85% of the medical patients who required late surgery. A significantly lower proportion of surgical than medical patients returned to work. Total inpatient costs for patients in the Coronary Artery Surgery Study (i.e, patients with stable angina) were $3432, $11,100 and $13,554 for medical, surgical and late surgical patients, respectively, for the first year in the study. There was no significant difference in the percentage of medical and surgical patients who were working at the end of 1 year. According to their own perceptions, the surgical group was in the best and the late surgical group in the worst health.

Aged↗
PubMed1982

Simultaneous myocardial revascularization and carotid endarterectomy.

Two methods for performing simultaneous carotid endarterectomy and coronary artery bypass grafting (CABG) were compared in 73 patients. A technique for performing carotid endarterectomy during cardiopulmonary bypass providing hypothermic cerebral protection was used in 37 patients (group 1). The 36 other patients (group 2) underwent carotid endarterectomy immediately before cardiopulmonary bypass was instituted. The mean age, New York Heart Association functional class, ventricular function and extent of carotid disease were similar in the two groups. The proportion of patients with previous myocardial infarction or stroke was higher in group 1 (p less than 0.05). One permanent neurologic deficit (technical error) and one transient neurologic deficit occurred in group 1 and none in group 2 (NS). Twenty-seven patients (37%) had left main disease, compared with an institutional incidence of 14.2% for all coronary operations. Five of seven patients who died early (three in group 1 and four in group 2) had left main disease. No advantage of one method over the other could be demonstrated. Patients with left main coronary artery disease and carotid disease have an increased operative risk.

Aged↗
PubMed1981

Coronary revascularization surgery: feasibility after myocardial infarction.

Since coronary revascularization improves prognosis in some patients with multivessel disease, can the potential benefits be extended to "prophylaxis" in selected postinfarction patients as well? These investigators sought the answer on the basis of patient characteristics, types of surgery, survival data, and mode of death in the postinfarction population of 129 patients who had early angiography.

Angiography↗
PubMed1981

Hospital mortality of re-replacement of the aortic valve. Incremental risk factors.

A total of 200 aortic vale re-replacements were performed between Jan. 1, 1975, and July 1, 1979. The re-replacements (RRP) were an isolated procedure or combined with coronary artery bypass grafting or resection of ascending aortic aneurysm. Ten patients (5%) died in hospital, compared with 24 (2.9%) among 842 patients undergoing isolated or combined initial aortic valve replacement (AVR) (p = 0.12). The mode of death was cardiac failure in six of the 10 patients, hemorrhage in two (from accidents at repeat sternotomy), and neurologic deficits in two (each with innominate vein transection at repeat sternotomy repaired by ligation). There were seven (3.9%) hospital deaths among 181 first RRP (p for difference from initial AVR = 0.5), but three (15%) of 19 died after the second or third RRP (p = 0.001). By simple contingency table analysis, preoperative New York Heart Association (NYHA) Class IV increased the risk of hospital death after RRP (p = 0.002), as did prosthetic valve endocarditis (p = 0.0005) and the use of cold ischemic arrest (p = 0.03). Logistic multivariate analysis showed advanced NYHA functional class (p = 0.02), use of cold ischemic arrest (p = 0.09), and increased aortic cross-clamps time (p = 0.03) to be incremental risk factors. Recommendations for reducing hospital deaths in the event of RRP are (1) reoperate before severe hemodynamic deterioration occurs, (2) plan and conduct the operation to minimize accidents from repeat sternotomy and dissection, (3) keep aortic cross-clamp time as short as possible, and (4) employ cold cardioplegia.

Aortic Valve↗
PubMed1981

Hemodynamic responses to anesthetic induction with midazolam or diazepam in patients with ischemic heart disease.

Hemodynamic responses to induction of anesthesia with midazolam maleate and diazepam were compared in patients with ischemic heart disease. While breathing 100% oxygen, 10 patients (group M) received midazolam maleate, 0.2 mg/kg, and 10 patients (group D) received diazepam, 0.5 mg/kg. In addition, 10 patients (group MN) breathing 50% nitrous oxide in oxygen received midazolam, 0.2 mg/kg. Patients in group M had a small but statistically significant (p less than 0.05) decrease (vs awake control values) in systemic and pulmonary arterial blood pressure, pulmonary arterial occluded pressure, stroke index, and left and right ventricular stroke work indices. Patients in group D experienced statistically significant decreases in systemic blood pressure. The only statistically significant differences between groups M and D occurred 5 minutes followed drug administration: heart rates were higher and systemic pressures and left ventricular stroke work indices were lower following midazolam. Hemodynamic changes following midazolam and nitrous oxide were similar to those observed in patients given midazolam and 100% oxygen. Patients in all three groups responded to endotracheal intubation with transient increases in blood pressure, heart rate, and systemic vascular resistance, but the hemodynamic values spontaneously returned toward control levels within 2 to 5 minutes. Although differing somewhat, midazolam, like diazepam, provided rapid, hemodynamically stable induction of anesthesia in patients with ischemic heart disease.

Anesthetics↗
PubMed1981

Midazolam versus diazepam: different effects on systemic vascular resistance. A randomized study utilizing cardiopulmonary bypass constant flow.

In 43 patients electively scheduled for myocardial revascularization surgery, a hemodynamic comparison of 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4] benzodiazepine (midazolam, Ro 21-3981, Dormicum) and 7-chloro-1,3-dihydro-1-methyl-5-phenyl-(2H)1,4-benzodiazepin-2-one (diazepam) was made during cardiopulmonary bypass. Midazolam and diazepam were compared in patients with ischemic heart disease to determine the effects of the drugs on systemic vascular resistance at constant flow (cardiac output) and temperature. Diazepam (0.3 mg/kg) produced significantly greater decreases in perfusion pressure, systemic vascular resistance, and venous reservoir volume than did midazolam (0.2 mg/kg). It was concluded that there are subtle differences in the pharmacologic actions of both midazolam and diazepam. When used with constant flow on cardiopulmonary bypass, diazepam causes more pronounced arterial and venous dilation. These data are at variance with the findings in intact man.

Anesthetics↗
PubMed1981

The Björk-Shiley valve: intermediate-term follow-up.

We evaluated 643 patients surviving aortic, mitral, and aortic and mitral ("double") valve replacement with the Björk-Shiley prosthesis from 1 to 72 months (median 38 months) postoperatively. Intermediate-term survival rate was similar to that reported for other prosthetic and bioprosthetic devices. Factors unrelated to the device, but related to preoperative patient characteristics or intraoperative or early postoperative events, had important association with late survival rate. These included previous valve replacement, concomitant ventricular aneurysm resection, black race, preoperative functional class, method of myocardial protection, duration of ischemic arrest, ventricular arrhythmias, and double valve replacement. Concomitant coronary artery bypass grafting and the type of valve lesion had no effect on survival prognosis. Freedom from thromboembolism was equal to or superior to other devices, but valve thrombosis occurred 16 times in 15 patients and caused 13 deaths. Improvement in New York Heart Association (NYHA) functional class occurred in the majority of patients. We conclude that the Björk-Shiley valve is durable and effective, but, as with other devices, is associated with problems of thromboembolism and thrombosis. Intermediate-term survival is related also to non-device, patient-associated characteristics.

Adolescent↗