Coronary artery bypass grafting in young adults.
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Adult↗
Biomedical subjects
B W Lytle
Publications and source records attributed to B W Lytle.
The internal mammary artery: coronary bypass conduit of choice.
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Coronary Artery Bypass↗
Fifteen hundred coronary reoperations. Results and determinants of early and late survival.
Fifteen hundred consecutive patients undergoing a first reoperation for coronary revascularization were reviewed to determine early and late results and predictors of survival. Patients were subdivided into cohorts on the basis of the year of reoperation: Group A (1967 to 1978, 436 patients); Group B (1979 to 1981, 439 patients); and Group C (1982 to 1984, 625 patients). Overall operative mortality was 3.4% (51 deaths): 4.6%, 2.3%, and 3.4% for Groups A, B, and C, respectively. Group C had significantly more women (p = 0.01) and patients with triple-vessel disease, left main coronary artery stenosis (greater than or equal to 50%), abnormal left ventricular function, age greater than or equal to 70 years, and graft failure as a surgical indication (all p less than 0.001). The mean interval between operations increased from 50 months for Group A to 84 months for Group C. At reoperation, Group C patients received more grafts, more internal mammary artery grafts, and had a higher prevalence of complete revascularization (all p less than 0.001). Univariate and multivariate analyses identified left main stenosis (p less than 0.0001), Class III or IV symptoms (p = 0.0002), advanced age (p = 0.0006), Group A (p = 0.02), and incomplete revascularization (p = 0.004) as predictors of increased in-hospital mortality. Follow-up of in-hospital survivors (mean interval 54 months, range 13 to 171 months) documented a 5 year survival rate of 90% and a 10 year survival rate of 75%. Multivariate testing identified advanced age (p less than 0.0001), hypertension (p less than 0.0001), and abnormal left ventricular function (p less than 0.0001) as predictors of decreased late survival.
Aged↗
Elective coronary surgery.
The goal of providing patent grafts distal to important coronary stenoses remains unchanged. Results of bypass grafting show the influence of refined technique, improved technology, and the longer followup now available. Coronary artery bypass is now routinely performed with low morbidity and mortality. Late attrition of saphenous vein grafts with concomitant deterioration of patients' clinical status has been increasingly recognized. The internal mammary graft, with its superior patency and impact on length and quality of survival, is gaining wider acceptance. Increased use of the mammary artery graft and extension of its use with bilateral and sequential grafting patterns are an important trend in the current practice of coronary surgery.
Angina Pectoris↗
Repeat mitral commissurotomy: long-term results.
Fifty-three patients underwent reoperation for open mitral commissurotomy (OMC) with one (1.9%) in-hospital death. The previous mitral operation was an OMC in 14 patients and a closed commissurotomy in 39. Mean age at the time of repeat OMC was 46 years (range 27 to 64), and NYHA functional class was II in 19 patients, III in 31, and IV in three. Follow-up of the 52 in-hospital survivors at a postoperative interval of 1 to 23 years (mean 10) documented 13 late deaths (mean interval 117 months, range 17 to 209) and survival of 96%, 83%, and 63% at 5, 10, and 15 postoperative years, respectively. Sixteen patients underwent subsequent mitral valve surgery (one OMC and 15 mitral valve replacements) 1 to 223 months after repeat OMC (mean 99), three patients within 5 years of repeat OMC. Reoperation-free survival was 94%, 74%, and 52% at 5, 10, and 15 postoperative years, respectively. Univariate testing did not document any correlation between age, functional class, rhythm, and either survival or reoperation-free survival. When feasible, repeat OMC can afford patients excellent long-term survival and relative freedom from prosthetic valve replacement.
Adult↗
Influence of the internal-mammary-artery graft on 10-year survival and other cardiac events.
We compared patients who received an internal-mammary-artery graft to the anterior descending coronary artery alone or combined with one or more saphenous-vein grafts (n = 2306) with patients who had only saphenous-vein bypass grafts (n = 3625). The 10-year actuarial survival rate among the group receiving the internal-mammary-artery graft, as compared with the group who received the vein grafts (exclusive of hospital deaths), was 93.4 percent versus 88.0 percent (P = 0.05) for those with one-vessel disease; 90.0 percent versus 79.5 percent (P less than 0.0001) for those with two-vessel disease; and 82.6 percent versus 71.0 percent (P less than 0.0001) for those with three-vessel disease. After an adjustment for demographic and clinical differences by Cox multivariate analysis, we found that patients who had only vein grafts had a 1.61 times greater risk of death throughout the 10 years, as compared with those who received an internal-mammary-artery graft. In addition, patients who received only vein grafts had 1.41 times the risk of late myocardial infarction (P less than 0.0001), 1.25 times the risk of hospitalization for cardiac events (P less than 0.0001), 2.00 times the risk of cardiac reoperation (P less than 0.0001), and 1.27 times the risk of all late cardiac events (P less than 0.0001), as compared with patients who received internal-mammary-artery grafts. Internal-mammary-artery grafting for lesions of the anterior descending coronary artery is preferable whenever indicated and technically feasible.
Coronary Artery Bypass↗
Reoperations for valve surgery: perioperative mortality and determinants of risk for 1,000 patients, 1958-1984.
One thousand consecutive cardiac reoperations for valve surgery in 897 patients were reviewed to determine in-hospital mortality and indicators of risk. Subgroups based on the number of previous cardiac procedures and the valve or valves replaced or repaired at reoperation (aortic valve, mitral valve, tricuspid valve, or multiple valves and mortality [deaths/number of procedures (% mortality)]) for those subgroups are as follows: (Table: see text) Predictors of increased risk for a first aortic valve reoperation were advanced age (p = .0002), endocarditis (p = .0018), female sex (p = .014), impaired left ventricular function (p = .039), and number of coronary vessels obstructed by 70% or more (p = .055). For a first mitral valve reoperation, the predictors were advanced age (p less than .0001), preoperative shock or cardiac arrest (p = .01), previous aortic or tricuspid valve operations (p = .02), type of mitral valve procedure (risk for repair of periprosthetic leak was greater than mitral valve replacement which was greater than mitral valve-conserving operation [p = .05]), and impaired left ventricular function (p = .059). For a first multiple valve reoperation, the predictors were diabetes (p = .04) and ascites (p = .02), whereas patients undergoing mitral valve replacement and tricuspid valve operations were at decreased risk (p = .01). Comparison of second reoperations with first reoperations indicates risk increases for multiple operations (p = .01) but not for aortic or mitral valve procedures. Rereplacement of a prosthesis (p = .007), coronary bypass grafting at reoperation (p = .006), and advanced age (p = .06) increased the risk for second reoperations. Age is the most consistent predictor of risk for patients undergoing valve reoperations.
Aortic Valve↗
Free (aorta-coronary) internal mammary artery graft. Late results.
Free internal mammary artery grafts were placed in 156 patients (1971 to 1985). Preoperative clinical and angiographic variables were similar to those of other series of isolated coronary bypass grafts. Of 244 total internal mammary artery grafts, 166 were in the aorta-coronary position and were performed mainly because of unsuitable saphenous veins or to gain additional graft length. One patient (0.6%) died during hospitalization. Perioperative complications included respiratory dysfunction in 16 (10.3%), reoperation for bleeding in 13 (8.0%), stroke in four (2.6%), myocardial infarction in three (1.9%), and wound complications in two (1.3%). Morbidity occurred significantly more often in the 1971 to 1975 period. Subsequently, eight (7%) had reoperation (6 to 158 months; mean 99 months). After a 98 month mean follow-up, the 10 year actuarial survival rate (including all causes of death) was 73.3%. Of 40 free grafts restudied within 18 months of operation, 31 (77%) were patent. The higher rate of early closure is attributed to technical problems early in our experience, especially construction of the aortic anastomosis. However, 32 of 35 (91%) free grafts studied after more than 18 months (mean 94 months) were open. Fifty of 58 (86%) free internal mammary artery grafts placed to the anterior descending coronary artery, seven of nine (78%) to the circumflex, and six of eight (75.0%) to the right coronary artery were patent. Sequential catheterization showed that of 24 free grafts open at 9 months, 24 remained patent at 80 months; when six of these were restudied at 93 months (third catheterization) and two (fourth catheterization) at 125 months, all were patent. These late studies of free internal mammary artery grafts showed no evidence of graft atherosclerosis. Free internal mammary artery grafts, like in situ internal mammary artery grafts, appear to have relative immunity from atherosclerosis. These findings expand the versatility of internal mammary artery grafting and justify wider use of free internal mammary artery grafts.
Adult↗
Early results of emergency surgery after coronary angioplasty.
During the period of our study 81 patients undergoing elective coronary artery angioplasty at our institution required emergency revascularization surgery within the ensuing 24 hr. The mean age of the 59 men and 22 women was 57 years (32 to 74 years). The principal indications for the emergency surgery were acute occlusion (n = 36), dissection (n = 28), unstable angina (n = 10), ventricular arrhythmias (n = 4), and unsuccessful balloon dilatation (n = 3). There were two early deaths and in 35 patients the presence of three criteria for myocardial infarction was noted postoperatively. Including these patients, 52 patients surviving their hospital course suffered 75 major complications. Emergency surgery after failed percutaneous transluminal coronary angioplasty can be performed with low mortality, but it carries a high incidence of major postoperative complications.
Adult↗
Perioperative risk of bilateral internal mammary artery grafting: analysis of 500 cases from 1971 to 1984.
The records of the first 500 patients (420 men, 80 women, mean age 55 years, range 24 to 78) undergoing bilateral internal mammary artery (IMA) grafting were reviewed to determine in-hospital morbidity and mortality. Sixty patients (12%) had had previous cardiac operations and 130 (26%) previous saphenous vein removal. From two to seven total grafts (mean 3.2) were performed, including 595 IMA grafts to the anterior descending or diagonal artery, 355 to the circumflex, and 105 to the right coronary system. To assess changing risks, the first 125 patients (group A, 1971 to 1982) were compared with the next 375 (group B, 1982 to 1984). Major complications in groups A and B included stroke, four (3.2%) vs ine (2.4%); wound complications requiring reoperation, three (2.4%) vs five (1.3%); prolonged (greater than 48 hr) respiratory care, seven (5.6%) vs 19 (5.1%); and death, two (1.6%) vs five (1.3%) (no p value less than .05). Complications significantly less frequent in group B were new Q waves in nine (7.2%) vs 10 (2.7%) in group A (p = .02) and reoperation for bleeding in 17 (13.6%) vs 16 (4.3%) in group A (p = .0003). Logistic regression analysis showed that major complications did not correlate with gender, diabetes, number of grafts, or preoperative left ventricular function but were associated with increasing age (p = .0001) and previous cardiac surgery (p = .009) and were decreased by the use of cardioplegia (p = .002). The excellent long-term patency of IMA grafts, combined with low and decreasing perioperative risk, supports the continued use of bilateral IMA grafting.
Adult↗
Results of mitral valve reconstruction.
To evaluate the early results of mitral valve reconstruction for mitral insufficiency, 117 consecutive cases were analyzed. Sixty-four (57.7%) of the patients were men, and the mean age was 60 +/- 13 years (range 18 to 85). Eighty-nine (76%) of the patients were in NYHA functional class III or IV preoperatively. The cause of the mitral disease was degenerative in 94 (80%) and rheumatic in 13 (11%) patients. Isolated mitral valve repair was performed in 56 patients (47.9%); the remainder underwent associated procedures that included myocardial revascularization in 38 (32.5%). Ninety-nine (85%) underwent a ring annuloplasty but in only seven (6%) was this the only repair technique. Resection of the posterior leaflet was performed in 41 (35%). There were five operative deaths (4.3%); one (1.8%) occurred after isolated repair and four (6.5%) after repair with associated procedures. All deaths occurred in patients greater than 65 years of age who were in NYHA functional class III or IV. Mean follow-up was 13.5 months (range 1 to 62). Two year actuarial survival was 90.6%. Three patients required reoperation (incidence of 2.5% per patient-year). Two patients sustained embolic events (incidence of 1.6% per patient-year). There were no anticoagulant-related complications. After surgery, 100 survivors (96.2%) were in NYHA functional class I or II.
Adolescent↗
Predictors of reoperation after myocardial revascularization.
The first 1,000 patients undergoing primary isolated myocardial revascularization each year from 1971 to 1978 were analyzed to define the incidence of reoperation and to elucidate the determinants of reoperation and reoperation-free survival. Six hundred sixty-six patients (9.7%) underwent reoperation in a mean of 6.9 +/- 3.2 years. Cumulative percent reoperation was 2.7% at 5 years, 11.4% at 10 years, and 17.3% at 12 years. The annual incidence of reoperation was 1.1% at 5 years and increased to 3.9% at 12 years. Twenty-five patient descriptors were analyzed for predictors of reoperation. Young age was found to be the most important predictor of potential for reoperation. Other risk factors in descending order of significance were absence of an internal mammary artery graft, incomplete revascularization, New York Heart Association Functional Class III/IV, and single or double vessel disease. Absence of an internal mammary artery graft was an important predictor for all age groups. In the multivariate analyses for risk factors for reoperation-free survival, absence of an internal mammary artery graft was the most important predictor. Other factors of major significance were smoking, incomplete revascularization, and moderate/severe left ventricular impairment. Internal mammary artery grafting neutralizes hypertension, serum cholesterol level higher than 300 mg/dl, and smoking as risk factors for reoperation-free survival.
Adult↗
Reoperation after previous grafting with the internal mammary artery: technique and early results.
Among 1,006 patients undergoing coronary bypass reoperation from 1968 through 1982, 100 had a patent internal mammary artery graft. There were 88 men and 12 women with a mean age of 53.4 years and a mean interval between first and second operations of 56.6 months. Reasons for reoperation were vein graft closure in 26% of the patients, progressive disease in previously ungrafted arteries in 48%, and combined indications in 26%. One operative death occurred. There was no significant difference in morbidity when compared with a reference group of 906 reoperations in patients without IMA grafting. Complete revascularization was achieved in 64% of the patients; the mean number of grafts per patient was 1.6. Seven patients had a perioperative myocardial infarction, and eight mammary artery pedicles were damaged during reoperation.
Coronary Disease↗
Determinants of blood utilization during myocardial revascularization.
Blood transfusion during cardiac surgical procedures has steadily decreased, but little information is available regarding the factors that determine its necessity or amount. To determine the predictors of blood utilization during myocardial revascularization, 441 consecutive patients undergoing primary myocardial revascularization were studied. Forty-four patients (10%) received blood during hospitalization with a mean transfusion of 0.3 +/- 1.4 units per patient. Age, sex, weight, body surface area, preoperative hematocrit, blood volume, and red blood cell volume were examined univariately for trends. All demonstrated a statistically significant trend for both need and amount of transfusion (p less than 0.001). Neither number of grafts nor duration of cardiopulmonary bypass demonstrated statistically significant trends. All univariately significant factors were evaluated by multivariate logistic regression analysis. Red cell volume was the best predictor of the need for transfusion (p less than 0.001), followed by age. No other factors improved predictive capabilities. We conclude that preoperative red cell mass and age are the principal determinants of the need for and quantity of blood transfused during myocardial revascularization. Use of this information may greatly improve the efficiency of ordering blood before operation.
Adult↗
Determinants of 10-year survival after primary myocardial revascularization.
The first 1000 patients undergoing primary isolated myocardial revascularization each year from 1971 to 1978 were analyzed to elucidate the determinants of long-term survival. Five-year survival was 93.2%, and 10-year survival was 79.3%. Five-year survivals were 96.1%, 94.2%, 92.1%, and 90.8%, respectively, for single, double, triple, and left main disease. Ten-year survivals for the same subsets were 88.6%, 83.0%, 74.9%, and 70.9%. Five-year survivals were 95.3%, 92.4%, 88.0%, and 81.3% for patients with normal, mild, moderate, and severe impairment of the left ventricle. Ten-year survivals for the same subsets were 84.1%, 76.5%, 65.8% and 53.6%. Patients receiving internal mammary artery grafts had 95.6% and 85.8% 5- and 10-year survivals that were superior to 92.0% and 76.2% in patients with only vein grafts. Patients completely revascularized had 95.0% and 82.5% 5- and 10-year survivals, while incompletely revascularized patients had lower (90.5% and 75.2%) 5- and 10-year survivals. Advancing age was the most important factor influencing late survival. Other risk factors in descending order of significance were impaired left ventricular function, no mammary artery graft, smoking, abnormal EKG, three vessel or left main disease, left ventricular end diastolic pressure (LVEDP) greater than 24, hypertension, 1971 to 1974 surgical era, cholesterol greater than 300, incomplete revascularization, and two vessel disease.
Adult↗
Mitral valve replacement combined with myocardial revascularization: early and late results for 300 patients, 1970 to 1983.
Of 300 consecutive patients undergoing primary operation for mitral valve replacement combined with coronary bypass grafting, 22 (7.3%) died in-hospital. Multivariate testing of preoperative and operative descriptors identified radiographic cardiac enlargement, preoperative paced rhythm or atrial fibrillation, 70% or more left main coronary obstruction, and serum bilirubin of more than 2 mg% as factors associated with an increase in in-hospital mortality. Follow-up of the 278 hospital survivors (mean interval 48 months, range 2 to 165 months) documented survival of 85%, 66%, and 31% and an event-free survival of 65%, 46%, and 21% at 2, 5, and 10 postoperative years, respectively. Cox proportional-hazard regression models of late risk implicated in-hospital ventricular arrhythmias, left ventricular dysfunction, and rheumatic or ischemic causes of mitral valve disease in decreasing long-term survival. In addition, patients with bioprostheses without warfarin anticoagulation had better survival and event-free survival than those with bioprostheses taking warfarin and those with mechanical prostheses with or without warfarin.
Aged↗
Mitral valve replacement. Results 20 years after operation.
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Adult↗
Long-term (5 to 12 years) serial studies of internal mammary artery and saphenous vein coronary bypass grafts.
Serial arteriograms were obtained in 501 patients after coronary bypass grafting. Study I within 5 years of operation (mean interval 15 months) and Study II more than 5 years after (mean interval 88 months, range 60 to 147 months). One hundred patients received both internal mammary artery and saphenous vein grafts: 37, mammary artery grafts only, and 364, vein grafts only. In Study I, 645 (82%) of 786 vein grafts were patent, 42 (5%) stenotic or irregular, and 99 (13%) occluded. Of 140 mammary artery grafts, 136 (97%) were patent, two (2%) stenotic, and two (2%) occluded. Of the 645 vein grafts patent in Study I, 357 (55%) remained patent in Study II, 119 (18%) were stenotic or irregular, and 169 (26%) were occluded. Of 136 mammary artery grafts patent in Study I, 130 (96%) were unchanged, one was stenotic, and five (4%) were occluded in Study II. Early vein graft patency was influenced by the coronary artery grafted and by angina. Progression of vein grafts patent at Study I to stenosis or occlusion at Study II was associated with increasing postoperative interval (p less than 0.00001), interval myocardial infarction (p less than 0.001), angina (p less than 0.001), diabetes (p less than 0.004), hypercholesterolemia (p less than 0.006), and hypertriglyceridemia (p less than 0.02); it was not influenced by the coronary artery grafted. Within 5 years of operation, mammary artery graft patency exceeded vein graft patency. Between 5 and 12 years after operation, the attrition rate of vein grafts greatly exceeded that of mammary artery grafts (p less than 0.0001).
Adult↗