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Biomedical subjects

K L Kayser

Publications and source records attributed to K L Kayser.

At least 19 recordsLinked to original sources
PubMed1992

Aspirin use and survival after coronary bypass surgery.

From Jan. 1, 1968, through Dec. 31, 1981, 5618 patients in a single cardiovascular surgery practice underwent coronary bypass surgery. Detailed clinical information was obtained during hospitalization and entered into a data base. All surviving patients were surveyed for aspirin use four times: in 1984, 1985, 1986, and 1987. A subgroup of 2395 patients gave consistent answers on every returned survey. The group that answered consistently "yes" had a 5-year survival rate of 79%; those who answered consistently "no" had a 5-year survival rate of 67%. Stepwise logistic regression showed that, after adjusting for patient characteristics, the relative risk of death was 58% (confidence interval 47% to 70%) for consistent aspirin users compared with consistent non-aspirin users. This study provides evidence that regular aspirin use after bypass surgery may enhance survival.

Actuarial Analysis↗
PubMed1992

Assessing providers of coronary revascularization: a method for peer review organizations.

OBJECTIVES: Current methods to evaluate quality of care are usually limited to reviews of individual cases or comparisons of hospital mortality rates. We present an alternative method that compares complication rates adjusted for patient characteristics. METHODS: Detailed clinical data that were specifically designed for quality comparisons of providers of revascularization procedures were abstracted from the medical records of 1998 Medicare patients, in 16 hospitals, who had coronary artery bypass surgery and 2091 patients, in 16 hospitals, who had angioplasty. Providers were ranked on the basis of an unadjusted risk, a risk adjusted for detailed clinical information, and a risk adjusted only for patient comorbidities. RESULTS: Complication rates differed significantly and substantially among the hospitals. Clinical adjustment changed the hospital rankings for the bypass surgery hospitals, but not for the angioplasty hospitals. Adjustment for comorbidities did not affect hospital rankings for either procedure. CONCLUSIONS: When sample sizes are limited, adverse outcome rates may be a more sensitive measure of quality of care than mortality rates. Rates that are unadjusted or adjusted only for comorbidities may be inadequate for evaluating some providers of bypass surgery.

Aged↗
PubMed1991

A randomized controlled trial of allopurinol in coronary bypass surgery.

A plethora of experimental evidence indicates that allopurinol reduces the formation of cytotoxic free radicals during myocardial ischemia and reperfusion. The purpose of this study was to evaluate the effect of allopurinol on cardiac performance and early mortality after coronary bypass surgery. Allopurinol (n = 89) or placebo (n = 80) was administered to 169 patients before surgery. Randomization produced groups evenly matched for surgical risk factors. Hospital mortality rate in the placebo group was 14 of 80 (18%) in the allopurinol group 4 of 89 (4%), p = 0.014. Cardiac performance, scored by cardiac index and the need for ionotropic or mechanical support, was significantly better in the allopurinol group. More nonfatal complications occurred in the allopurinol group. When either a complication or death is termed an event, the proportion of events was equal in the two groups. No side effects were identified. We now administer allopurinol to all patients who are undergoing bypass surgery unless specifically contraindicated.

Adult↗
PubMed1989

Factors influencing long-term (10-year to 15-year) survival after a successful coronary artery bypass operation.

The long-term survival of 6,181 consecutive patients who underwent a coronary bypass operation from 1972 to 1986 was evaluated in relation to certain risk factors: age at the time of operation, sex, preoperative left ventricular function, presence of diffuse coronary artery disease, and previous coronary bypass operation. Advanced age markedly reduced the 10-year and 15-year survival. When compared with the general population, however, the survival of patients in the older age groups (over 60 years) exceeded that of the general population at 10 and 15 years. In patients under 55 years of age, the 10-year and 15-year survival is less than that of the general population. Male and female patients of comparable ages had virtually identical 10-year and 15-year survival rates. Severe left ventricular dysfunction, previous coronary bypass operation, and diffuse coronary artery disease requiring coronary artery endarterectomy all adversely affected the long-term survival rates. Within all age groups studied there was a significant benefit in survival with either one or more mammary artery bypass grafts. The data presented provide an important historical control group that can be used in evaluating the long-term results after successful coronary bypass operations.

Adult↗
PubMed1988

Triple vessel coronary artery endarterectomy and reconstruction: results in 144 patients.

Coronary artery endarterectomy and reconstruction are valuable adjuncts to conventional bypass surgery when attempting to revascularize "diffusely" diseased coronary arteries. One hundred forty-four consecutive patients were operated on through February 1986, all of whom required endarterectomy and reconstruction of the left anterior descending, left circumflex and right coronary arteries. There were 130 men (90%), ranging in age from 29 to 83 years (average 55.8), whose left ventricular ejection fraction ranged from 0.20 to 0.75 (average 0.54). One hundred thirty-one patients (91%) had angina preoperatively, which was Canadian Cardiovascular Society class III or IV in 85 (59%). Fifteen operations (10%) were repeat procedures. All operations were performed using intermittent ischemic arrest. There was an average of 5.0 grafts per patient (range 3 to 8), with an average of 3.8 endarterectomized vessels per patient (range 3 to 7). There were 14 surgical deaths (10%), all cardiac in origin. Statistically significant (p less than 0.01) risk factors for increased operative mortality included repeat surgery, ejection fraction less than or equal to 0.30 and age greater than or equal to 70 years. The operative mortality rate in 106 low risk patients (male gender, age less than 70 years, ejection fraction greater than 0.30, first operation) was 3.8% (4 patients). Nonfatal complications included 13 perioperative myocardial infarctions (10%). Long-term follow-up data are available for all 102 surviving patients for an average of 30 months (range 7 to 92). There were 12 late deaths 1 to 52 months postoperatively. The 5 year actuarial survival rate is 71% for the entire group and 87% for the 106 low risk patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Results of coronary artery endarterectomy and reconstruction.

Since 1978, 5005 patients have had coronary artery bypass operations: 50% had conventional grafts only (group A), 25.1% required one coronary artery endarterectomy (group B), and 24.9% required multiple endarterectomies (group C). Operative mortality and long-term survival were stratified within each group according to the presence of additional risk factors: severe left ventricular dysfunction, repeat operation, insulin-dependent diabetes mellitus, female sex, and age over 70 years. Operative mortality was 4.0% in group A patients, 6.3% in group B, and 10.4% in group C; it increased in each group as the number of risk factors increased. Mortality was higher in patients with a left coronary artery endarterectomy compared to those with a right coronary endarterectomy only when multiple risk factors were present. Perioperative myocardial infarction occurred in 5.6% of group A patients, 6.5% of group B, and 13.1% of group C patients. Early graft patency (940 patients, 18.8%) was 801 of 901 (88.9%) for endarterectomy grafts and 2939 of 3248 (90.5%) for conventional grafts. Late patency (over 1 year) in 288 symptomatic patients was 137 of 191 (71.1%) for endarterectomy grafts and 644 of 850 (75.8%) for conventional vein grafts. Long-term (5-year) actuarial survival rate was reduced in patients requiring endarterectomy. Current anginal status is available for 3011 of 3305 patients (91.1%): 28.9% of group A patients, 32.5% of group B, and 33.7% of group C patients have recurrent angina at an average follow-up of 58.3 months. The results of this study show increased operative mortality and morbidity in patients requiring coronary artery endarterectomy and reconstruction. However, the early results and particularly the late survival, clinical status, and continued graft patency justify this approach in patients with diffuse coronary artery disease, many of whom would otherwise be inoperable.

Adult↗
PubMed1988

Coronary artery bypass grafting for the third time or more. Results of 150 consecutive cases.

Through December 1986, coronary artery bypass surgery was performed on 150 patients who had undergone at least two previous myocardial revascularization surgeries. One hundred thirty-seven patients had two, 12 patients had three, and one patient had four previous operations. There were 117 men (78.0%); the mean age was 55.5 years (range, 28-76 years); 137 patients (91.3%) had triple-vessel disease, and 36 (24.0%) had a left ventricular ejection fraction less than 0.40. One hundred forty-nine patients (99.3%) had angina preoperatively, with 142 (94.7%) having Class III and IV angina. Direct myocardial revascularization was performed in all patients, with a mean of 3.3 grafts per patient (range, 1-6). In addition, coronary artery endarterectomy was performed in 70 cases (46.7%): right coronary artery endarterectomy in 15 (10.0%), left coronary artery endarterectomy in 39 (26.0%), and multiple coronary artery endarterectomies in 16 (10.7%). There were 18 in-hospital deaths (12.0%). Statistically significant risk factors for increased early mortality (p less than 0.01) included age over 65 years and left ventricular ejection fraction less than 0.40. Diffuse coronary artery disease requiring multiple coronary artery endarterectomies almost achieved statistical significance as a risk factor (p = 0.06). Complications in the surviving 132 patients included seven nonfatal perioperative myocardial infarctions (5.3%). Follow-up data for a period of 8-172 months (mean, 43.1 months) is available for 100 of 103 patients (97.1%). Five-year actuarial survival was 76.4% for the entire series and 87.3% for hospital survivors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Combined valve replacement and coronary bypass surgery. Results in 127 operations stratified by surgical risk factors.

The results of 127 operations with both valve replacement and coronary bypass were compared with all 5,053 operations involving coronary bypass performed from August 1972 through June 1985. Both groups were stratified by the number of risk factors (age over 70 years, bad ventricle, extensive endarterectomy, and reoperation). Compared with all bypass operations, valve replacement had no effect on surgical mortality except in the group at highest risk. Conversely, valve replacement was associated with reduced late survival in all but those at highest risk. Results with tissue valves were better than with mechanical, but statistical significance was lacking. Relief of angina was equal. Ischemic mitral insufficiency continues to be the greatest challenge, with 46 percent five-year survival. We conclude that combined valve replacement and bypass surgery can be performed successfully, even in the patients at higher risk; however, this operation should be performed only by teams with demonstrated success in surgically treating advanced coronary artery disease.

Adult↗
PubMed1978

Use of intra-aortic balloon pumping (IABP) in clinical cardiac surgery and management of patients with IABP.

One hundred thirty eight patients were reviewed which required IABP assist. Sixty nine (84 per cent) of 82 patients who had been able to come off cardiopulmonary bypass despite increasing pharmacologic support survived operation and 56 patients (68 per cent) discharged hospital. Twenty three (75 per cent) of 31 patients who took for elective coronary artery surgery as extremely high risk because of extensive three vessel coronary artery disease and severely compromised left ventricular function discharged hospital. In summary, hospital death was 35 per cent, late death 12 per cent and long term survivors 54 per cent. Severe complication concerned with inserting balloon catheter occurred in two cases (1.4 per cent) which were abdominal aortic dissection and laceration of iliac artery. At the present time, the primary indication for IABP is in assistance of the open heart surgical patient. Thre are three important factors in successfully managing the patients with IABP. First, begin IABP assist as soon as possible if indicated. Second, keep an adequate circulating volume with mean left atrial pressure being maintained around 20 mmHg and cardiac index at 2.1 L/min./M or greater. Third, improve the peripheral vascular circulation, which might need peripheral vasodilator.

Assisted Circulation↗