Donald H. Glaeser

Patterns of atherosclerosis and their surgical significance.

The records of 13,827 patients admitted on one or more occasions to The Methodist Hospital in Houston on the service of the senior author for the treatment of arterial atherosclerotic occlusive disease from 1948 to 1983 were analyzed. The data derived from this analysis are believed to support the concept that atherosclerotic occlusive disease tends to assume characteristic patterns that may be classified, by predominant site or distribution of the disease, into five major categories: (I) the coronary arterial bed, (II) the major branches of the aortic arch, (III) the visceral arterial branches of the abdominal aorta, (IV) the terminal abdominal aorta and its major branches, and (V) a combination of two or more of these categories occurring simultaneously. Category IV had the highest proportion of patients (about two-fifths), Category I the second highest (almost one-third), and Category III had the lowest percentage (3%). Atherosclerotic occlusive disease in all categories tends to be well localized and usually occurs in the proximal or midproximal portions of the arterial bed. Such lesions are amenable to effective surgical treatment directed toward restoration of normal circulation. Less commonly, however, the occlusive disease in all categories occurs predominantly in the distal portions of the arterial bed, and such lesions are usually not amenable to effective surgical treatment. Patients in Categories I and III were significantly younger than those in the other categories and, although males predominated in all categories, Categories II and III contained significantly more female patients than did the other categories. In general, however, female patients behaved like male patients in virtually all aspects of the study. The rates of progression of the disease may be classified into: rapid (0 to 36 months), moderate (37 to 120 months), and slow (more than 120 months). The rapid and moderate rates of progression occurred most frequently in Categories II and IV, and the moderate and slow rates occurred most frequently in Category I. The possibility for development of recurrence or progression of disease in the same category and in a new category was significantly greater in younger patients. The patients sex had no significant influence in this regard. Among the various categories, patients in Category IV had the highest incidence of development of disease in a new category, and Category I had the lowest incidence. Patients originally in Category II had a somewhat greater tendency to development of disease in Category IV, and patients originally in Category IV, for development of disease in Category II.(ABSTRACT TRUNCATED AT 400 WORDS)

Left ventricular diastolic performance at rest and during exercise in patients with coronary artery disease. Assessment with first-pass radionuclide angiography.

We used first-pass radionuclide angiocardiography to assess filling fraction during the first third of diastole, peak filling rate and peak filling rate during the first third of diastole as indexes of left ventricular diastolic performance at rest and after upright bicycle exercise in 32 normal patients and 68 patients with coronary artery disease. The mean filling fraction was unchanged from rest to exercise in normal patients (47 ± 15% vs 46 ± 13%; NS). Even in 49 coronary patients with normal (⩾ 50%) ejection fraction at rest, filling fraction was less than that in normal patients at rest (35 ± 11% vs 47 ± 15%, p < 0.001). Despite similar resting heart rates, patients with coronary disease had lower (p < 0.001) peak filling rate and peak filling rate during the first third of diastole than normal patients. With exercise, filling fraction decreased (p < 0.001) from the resting value in coronary patients. These data suggest that (1) indexes of diastolic performance can be noninvasively assessed at rest and during exercise using first-pass radionuclide angiocardiography, (2) abnormalities in early diastolic performance are often present at rest in patients with coronary artery disease despite normal systolic performance, and (3) exercise-induced ischemia results in increased early diastolic dysfunction in patients with coronary disease.

The influence of residual disease after coronary bypass on the 5-year survival rate of 1274 men with coronary artery disease.

To determine the independent influence of the extent and site of residual disease on late survival, we analyzed the fate of 1448 consecutive patients who had coronary artery bypass surgery during 1968-1974. There were 1274 males, mean age 53.4 ± 8 years (range 24-75 years). Females were excluded from further analysis. Two hundred twenty-six patients (17.7%) had one-vessel disease, 492 (38.6%) had two-vessel disease, 408 (32.0%) had three-vessel disease and 148 (11.6%) had left main stenosis. Survival was determined at a follow-up of at least 5 years. Survival data were analyzed by Kaplan-Meier survival curves for the patients with two- and three-vessel disease according to the extent of residual disease. For patients with two-vessel disease and good ventricular function, survival was similar at 5 years, 89.1 % and 87.7% for no and one residual lesion; for those with two-vessel disease and poor ventricular function, 5-year survival was 84.5% and 52.6% for no and one residual lesion; for those with three-vessel disease and good ventricular function, it was 92.0 %, 83.4%, and 75.0% for no, one and two residual lesions, respectively. With poor ventricular function, the corresponding results were 83.1%, 72.5% and 23.1%. The Cox multivariate analysis technique was used to analyze the influence of age at operation, number of vessels diseased preoperatively, preoperative left ventricular function, period of surgery, and the number and site of residual lesions after operation. Residual disease, age at operation and left ventricular function were the most important variables affecting survival of patients with two- and three-vessel disease. Residual lesions of the left anterior descending or circumflex coronary arteries were the most important predictors of survival; residual lesions of the right coronary artery exerted a lesser influence. The results of this study suggest that the greatest benefit in terms of improved survival may come from the first two to three grafts placed.

Conventional heart rate variability analysis of ambulatory electrocardiographiic recording fails to predict imminent ventricular fibrillation

OBJECTIVES The purpose of this report was to study heart rate variability in Holter recordings of patients who experienced ventricular fibrillation during the recording. BACKGROUND Decreased heart rate variability is recognized as a long-term predictor of overall and arrhythmic death after myocardial infarction. It was therefore postulated that heart rate variability would be lowest when measured immediately before ventricular fibrillation. METHODS Conventional indexes of heart rate variability were calculated from Holter recordings of 24 patients with structural heart disease who had ventricular fibrillation during monitoring. The control group consisted of 19 patients with coronary artery disease, of comparable age and left ventricular ejection fraction, who had nonsustained ventricular tachycardia but no ventricular fibrillation. RESULTS Heart rate variability did not differ between the two groups, and no consistent trends in heart rate variability were observed before ventricular fibrillation occurred. CONCLUSIONS Although conventional heart rate variability is an independent long-term predictor of adverse outcome after myocardial infarction, its clinical utility as a short-term predictor of life-threatening arrhythmias remains to be elucidated.

Patterns of atherosclerosis: effect of risk factors on recurrence and survival—analysis of 11,890 cases with more than 25-year follow-up

A series of 11,890 patients from the senior investigators surgical service between 1949 and 1998 is analyzed for the significance of distinct risk factors for recurrence of, and survival from, atherosclerotic occlusive disease. Eight risk factors have been assessed for their importance in 4 defined arterial categories (the coronary arterial bed, the branches of the aorta, the abdominal visceral [celiac, superior mesenteric, and renal] arteries, and the terminal abdominal aorta and its major branches) in determining survival rate of the entire group and their impact on rate of recurrence of atherosclerosis in a subgroup of 5,568 patients who had > or =1 postoperative arteriogram, permitting precise identification of changes in the atherosclerotic process. Patients in these 2 groups were followed for > or =25 years; univariate and multivariate analyses were used. On admission all patients had symptomatic atherosclerotic occlusive disease in a single vascular category. Each patient was treated surgically for alleviation of the disease. Two primary outcomes are included: (1) survival, by atherosclerosis category, in all 11,890 patients; and (2) recurrence, also by category, in the subset of 5,568 patients. Multivariate results for recurrence showed little consistency across categories. Only 1 risk factor, diabetes, appeared in 2 of the 3 categories fully analyzed. Other variables that are significant in only a single category are male sex, cholesterol, hypertension, and smoking. Survival showed much greater consistency, with age, diabetes, and hypertension significant in all 3 categories, male sex and smoking in 2, and cholesterol in only Category I. Univariate results followed much the same trend. For recurrence and survival, the response of the arterial bed to the risk factors in each of the 4 categories is distinctly different, an observation that we have not found to be previously reported.

Late results of reconstructive surgery for renovascular disease.

In order to determine the late results of reconstructive surgery for renovascular disease, a review was made of a series of 505 consecutive patients who underwent operation over a 20-year period. There were 257 males (50.9%) with an age range of 3–80 years. Renal artery bypass grafts were used in 75.4% (471/625) and thromboendarterectomy and/or patch angioplasty in 15.0% (94/625) of reconstructions. Associated vascular procedures were performed in 38.0% (186/489) of patients. Operative mortality (30-day) was 1.8% (9/489) overall, and 4.8% (9/186) with associated procedures but there was no operative mortality in 303 consecutive isolated renal artery reconstructions. The blood pressure was normal or improved in 65% of patients at a mean follow-up interval of 49.3 months, range 1–240 months. The best response rate was obtained in younger patients with isolated renal lesions. Linear regression analysis showed age at operation to be the most important determinant of blood pressure response (p < 0.003) with the presence or absence of diffuse atherosclerosis as another but less powerful determinant of responsiveness (p < 0.07). Crude 15-year survival was 70% (340/489). The overall five- and ten-year actuarial survival probabilities were 80 and 62% respectively. The most common causes of death were myocardial infarction, stroke, and cancer. Cox regression analysis for variables influencing survival indicated that age at operation (p < 0.001), sex (p < 0.01) and the presence or absence of fibromuscular disease (p < 0.002) were the major determinants of late survival with persistent severe hypertension exerting an important but lesser influence. The results of this study indicate that about two-thirds of patients will experience long-term relief of hypertension after operation and that the best long-term survival and blood pressure relief will be obtained in patients less than 50 years of age. Because hypertension in females is better tolerated, younger, male patients appear to have the most to gain from successful renovascular reconstruction.

Renovascular reconstruction: factors affecting long-term prognosis in 919 patients followed up to 31 years.

During the 31-year period from May 3, 1955, to May 12, 1986, renovascular reconstructions were performed on 919 patients. The mean age of the 529 men was 54 +/- 0.58 (SE) years and, of the 390 women, 48 +/- 0.7 years. Mean preoperative diastolic blood pressure was 110 +/- 0.6 mm Hg. The most common causes of renal artery stenosis were atherosclerosis in 647 patients, fibromuscular disease in 161 patients, and renal artery aneurysm in 51 patients. In the remaining 60 patients, other causes were present, including kinks and fibrous bands. The most common surgical procedures were Dacron bypass graft (780 arteries) and endarterectomy with or without a patch graft (329 arteries). Four hundred sixty-nine patients had associated operations, the most common of which were abdominal aortic aneurysmectomy in 231 and aortoiliofemoral reconstruction in 141 patients. The perioperative mortality rate was 5.5% (51 of 919 overall); for renal procedures alone, it was 1.7% (8 of 450) and for combined surgical procedures, 9.2% (43 of 469). The overall graft patency rate at a follow-up of 18.8 +/- 1.9 months was 88.6% (381 of 430) and at a second follow-up of 50 +/- 4.3 months, 86.7% (111 of 128). Analysis of long-term blood pressure response and factors affecting late survival indicated that patients with preoperative diastolic pressures of greater than 100 mm Hg and renal artery stenosis of greater than 70% had the best blood pressure responses and that male sex, increasing age, bilateral renal stenosis, and associated vascular operations lowered the survival rate whereas fibromuscular disease enhanced the duration of survival.(ABSTRACT TRUNCATED AT 250 WORDS)

The St. Jude Valve prosthesis: Analysis of the clinical results in 815 implants and the need for systemic anticoagulation

Between July 1979 and December 1984, 785 patients received 815 St. Jude Medical valve prostheses. Valve-related mortality in the follow-up period was due to thromboembolism in seven cases, anticoagulant-related hemorrhage in three and perivalvular leak in two. Freedom from valve-related death or reoperation at 3 years was 96.4% for aortic valve replacement and 98.3% for mitral valve replacement. The overall rate of thromboembolism was 2.6%/patient-year with warfarin, 9.2%/patient-year with antiplatelet medication and 15.6%/patient-year in patients with no anticoagulant therapy. One episode of thrombotic obstruction of a mitral valve, in a patient receiving no anticoagulant therapy, resulted in an occurrence rate of such obstruction of 0.22%/patient-year. Valve replacement with the St. Jude valve produced excellent clinical results, but long-term anticoagulation with warfarin was required to minimize thromboembolic complications. The use of antiplatelet agents alone provided inadequate protection.

Membrane vs bubble oxygenator: clinical comparison.

Numerous studies have demonstrated the superiority of membrane oxygenators (MO) over the bubble oxygenators (BO) when used for prolonged cardiopulmonary support. However, there is little information available evaluating the MO for routine, short-term cardiopulmonary bypass. In this study the 5MO314 Modulung-Teflo (MO) was compared to 5M30314 Miniprime Variflo (BO). The data of 91 patients (46 MO and 45 BO) were analyzed according to the duration of cardiopulmonary bypass (Group I less than 60 min., Group II 60-90 min. and Group III greater than 90 min.). Hemodynamic parameters, fluid and blood balance, as well as hematologic and blood gas studies were used for comparing the two oxygentors. The hemodynamic parameters were better, and the arterial blood gases were more physilogic with the MO. The postoperative blood loss was significantly less when using the MO. The other measurements documented the stability of the MO. All statements were based on statistical analysis with a DEC PDP-9 computer, using the MIIS language and operating system. Consequently, we are now using this MO for routine cardiopulmonary bypass.

Outcomes in single versus bilateral internal thoracic artery grafting in coronary artery bypass surgery.

The authors analyzed the early outcomes in two groups of patients undergoing coronary artery bypass grafting (CABG) with single versus bilateral internal thoracic arteries (ITA) in their institution. One thousand sixty-nine patients underwent CABG with single or bilateral ITAs from 1990 to 2000. Of these patients, 911 (85.2%) had single ITA and 158 had bilateral ITA (14.8%). The incidence of tobacco abuse was 40.3% in the single ITA group and 56.7% in the double ITA group (P = 0.0001). The incidence of perioperative myocardial infarction, renal failure, reoperation for bleeding, stroke, or operative mortality did not differ in the two groups. There was a 4.4% incidence of mediastinitis in the bilateral ITA group versus 2.2% in the single ITA group (P = 0.0602). Early outcomes after bilateral ITA grafting for CABG are similar to single ITA grafting. Careful judgment should be exercised in selecting patients for bilateral ITA grafting, particularly if the patient smokes.