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 investigator's 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.

Left ventricular volume reduction and reconstruction in ischemic cardiomyopathy.

BACKGROUND: Ischemic cardiomyopathy can be the result of large or small myocardial infarctions or due to myocardial hibernation. Patients with an end-systolic volume index >100 mL¿m2 do not benefit from revascularization alone and require an operation that reduces ventricular volume. Various approaches to reduce ventricular volume have been described. We applied several of these techniques in patients with end-stage ischemic cardiomyopathy. METHODS: Forty eight patients with end-stage ischemic cardiomyopathy (Class III-IV) underwent left ventricular volume reduction operations with coronary revascularization and mitral valve repair or Alfieri valvoplasty. Fourteen patients underwent interpapillary resections, 22 anterior resections, 4 posterior resections, 2 anterior and posterior resections, and 6 patients reduction of left ventricular volume with endocavitary patches. RESULTS: All the techniques used improved left ventricular function. Analysis of mortality revealed that extensive resections (interpapillary, anterior, and posterior resection) had a 43% mortality. However, a limited resection or a ventricular reconstruction with an endocavitary patch had only a 12.5% mortality. When we changed our approach to a more conservative one, mortality was reduced from 26% the first 12 months to 13% in the last 15 months of the study. CONCLUSIONS: Ischemic cardiomyopathy has a poor prognosis if the end-systolic volume index exceeds 100 mL/m2. Various procedures exist to reduce left ventricular volume. Extensive ventricular resections improve ventricular function, but have a high mortality. This led us to use other methods of ventricular volume reduction such as more conservative resections combined with left ventricular reconstructions or ventricular volume reduction with endocavitary patches. Mortality was reduced significantly by this approach. The patients that survived have remained Class I-II in a follow-up that extends up to 30 months. Surgical therapy of Class III-IV ischemic cardiomyopathy is feasible, but aggressive ventricular resections have a high mortality. We advocate a more reconstructive approach with limited or no ventricular resection.

Hemodynamic effects of different pacing ratios in chronic dynamic double cardiomyoplasty.

BACKGROUND: Dynamic cardiomyoplasty is being used clinically worldwide, and evaluated by a clinical trial (phase III) in the United States. Some centers stimulate the skeletal muscle wrap with every heart beat (1:1 [muscle:heart]), whereas others use every other heart beat (1:2). Recent concern over the possible deleterious effects of too-frequent stimulation of the muscles motivated the attempt to evaluate, in a canine model of chronic, double cardiomyoplasty, the effects of two different pacing ratios on several hemodynamic parameters of interest. METHODS: Double cardiomyoplasty was performed using both latissimus dorsi muscles in 11 dogs. Fatigue resistance was achieved using the clinical transformation protocol. At a final experiment, acute cardiac failure was induced by administration of propranolol. Hemodynamic measurements of eight physiologic variables were averaged over complete pacing cycles, including the nonpaced beat at a 1:2 pacing ratio. RESULTS: The net effects of latissimus dorsi muscle stimulation at each of two pacing ratios were compared using nonparametric statistics. With the exception of left ventricular pressure (p = 0.0262) and its first derivative, dP/dt (p = 0.0099), there was no significant difference between hemodynamic performance at the two pacing ratios. CONCLUSIONS: In this canine model, pacing every other beat produces hemodynamic results that are statistically similar to pacing every beat. Less frequent stimulation of the latissimus dorsi muscle may preserve its function and improve clinical results without compromising hemodynamic benefit.

Acute impairment of coronary blood flow by dynamic cardiomyoplasty.

The aim of this study was to quantify the effects of three different configurations of cardiomyoplasty on coronary blood flow in an acute dog model. Thirteen dogs had both latissimus dorsi muscles harvested and transposed to the chest. Coronary blood flow was measured using Doppler cuff probes on the left anterior descending and circumflex coronary arteries during each of three cardiomyoplasty configurations: left posterior, right anterior, and double. Multiple beat measures were made of systolic and diastolic flow during a control protocol and a subsequent protocol with the muscle(s) paced. Significant flow reductions during pacing were observed in the left anterior descending coronary artery during left posterior (17%, p = 0.003), right anterior (29%, p < 0.0001), and double (35%, p = 0.0001) myoplasty. Similar reductions occurred in the circumflex artery (14%, p = 0.0009; 20%, p = 0.001; 27%, p = 0.0053). The net flow over an entire pacing cycle also was reduced significantly: left anterior descending artery (11%, p = 0.0035; 23%, p = 0.0001; 23%, p = 0.0047) and circumflex artery (10%, p = 0.0025; 17%, p = 0.0018; 21%, p = 0.0091). Thus, in the acute setting cardiomyoplasty depresses coronary blood flow. A chronic setting will be needed to determine the ultimate significance of these results.

New configuration of double cardiomyoplasty based on studies of the length-tension properties of the latissimus dorsi muscle.

A new configuration of double cardiomyoplasty was designed according to studies of the length-tension properties of the linear latissimus dorsi muscle. Four dogs had both their right and left latissimus dorsi muscles dissected from the chest wall and attached to a tensiometer to measure force of contraction. The maximum active tension obtained with stimulation of the linear latissimus dorsi muscle was observed when the muscle was at its resting anatomic length and up to 5% above this length. Eight dogs had a double cardiomyoplasty in which the resting anatomic length of both muscles was maintained. Control hemodynamic parameters obtained with the muscles at rest were compared with stimulated muscle protocols. In a normal heart state, stimulation of the double cardiomyoplasty increased the cardiac output 32% (p < 0.05), the stroke volume 39% (p < 0.05), and the left ventricular pressure 42% (p < 0.05). When acute heart failure was induced with high-dose intravenous propranolol (5 mg/kg), stimulation of the double cardiomyoplasty increased the cardiac output 32% (p = 0.01), the stroke volume 32% (p < 0.05), rate of pressure rise 39% (p < 0.01), and myocardial thickening 39% (p < 0.01). The study demonstrated that this configuration of double cardiomyoplasty provides significant hemodynamic assistance in the normal and acutely failing canine heart.

Effects of low dose transdermal scopolamine on heart rate variability in acute myocardial infarction.

OBJECTIVES: We hypothesized that by enhancing parasympathetic activity, low dose transdermal scopolamine would increase heart rate variability after myocardial infarction. BACKGROUND: Low heart rate variability is associated with increased mortality after acute myocardial infarction. METHODS: Conventional time domain heart rate variability was measured from 24-h Holter recordings of 61 consecutive male patients (mean age 58 +/- 10 years, left ventricular ejection fraction 44.7 +/- 15.5%) 6 days (median) after acute myocardial infarction. Patients were then randomly assigned to wear one patch of transdermal scopolamine or a matching placebo patch for 24 h, during which their 24-h heart rate variability was remeasured. RESULTS: Compared with placebo, transdermal scopolamine caused a significant increase in time domain measures of 24-h heart rate variability by 26% to 35% above baseline. Transdermal scopolamine was well tolerated. CONCLUSIONS: Low dose transdermal scopolamine safely increases cardiac parasympathetic activity and short-term heart rate variability after acute myocardial infarction. Whether the effect of transdermal scopolamine on heart rate variability is a reasonable surrogate for improvement of long-term morbidity and mortality requires an appropriate designed investigation.

Conventional heart rate variability analysis of ambulatory electrocardiographic recordings 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.

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.

Determinants of survival 10 to 14 years after coronary bypass: analysis of preoperative variables in 1,448 patients.

To determine which preoperative variables were most predictive of long-term survival after coronary bypass surgery, the status of 1,448 consecutive patients was determined 10 to 14 years after operation. All patients were operated on at least 10 years ago and follow-up at 10 years was 93.8% complete. The overall 14-year survival probabilities were: for one-vessel disease, 73.3%; for two-vessel disease, 45.9%; for three-vessel disease, 34.2%; and for left main coronary artery disease, 41.9%. Patients with good left ventricular function had an overall survival rate of 53.3%, and patients with poor ventricular function had a survival rate of 31.9%. Preoperative variables predictive of greater risk of total mortality were: digoxin usage, multivessel disease, poor quality of left ventricular function, age at operation, electrocardiographic evidence of myocardial infarction, previous stroke, diabetes, heart failure, diuretic usage, cigarette smoking, and residual ungrafted coronary artery disease. The major determinants of long-term survival were variables associated with preoperative left ventricular function. Diabetes was the only important metabolic risk factor identified. This study suggests that unfavorable preoperative conventional risk factors should not be considered a contraindication to operation in patients with adequate coronary anatomy and left ventricular function.

Influence of diabetes mellitus on the results of coronary bypass surgery. Follow-up of 212 diabetic patients ten to 15 years after surgery.

To determine the long-term influence of the severity of preoperative diabetes mellitus on the results of coronary bypass, a review was made of 212 diabetics operated on between 1968 and 1973, of whom 87 patients (41%) were receiving no drugs, 108 patients (50.9%) were receiving oral hypoglycemic agents, and 17 patients (8%) were receiving insulin. They were compared with 1,222 nondiabetic patients operated on over the same period. Perioperative mortality was similar in the diabetics and nondiabetics: 7.1% vs 4.5%. Improvement in anginal symptoms was similar in all patient groups: 85.9% to 92.7%. Overall 15-year survival probability was .53 for the nondiabetic group, .43 for the diabetics not receiving drugs, .33 for those receiving oral agents, and .19 for the insulin-treated patients. Late graft patency ranged from 78% to 90% and was comparable in all groups. The preoperative blood glucose level was an important predictor of late mortality in all diabetic patients. Thus, coronary bypass surgery was effective in all groups of diabetic patients in long-term relief of anginal symptoms. Intermediate-term survival rates were good in all groups, but the initial severity of the diabetes was an important determinant of long-term survival rates.

Pacemaker follow-up: its role in the detection and correction of pacemaker system malfunction.

The goal of pacemaker follow-up is not only to detect battery depletion but also to detect all malfunctions of the pacing system and, when possible, to correct such problems using programming. During one year, we discovered 61 such malfunctions in a clinic of 1065 patients (5.7%). These were more frequent in the first year (7.7%) than in the third to fifth years of follow-up (range 3.1-4.8%). The incidence rose again in the sixth and subsequent years (7-7.7%). Despite a significant occurrence of malfunctions (5.2%) among multiprogrammable pacemakers, the necessity for operative intervention for their correction was low (1.2%). Sensing problems were the most common (57%) and the most likely to be corrected by reprogramming (85%); problems involving loss of capture were less likely to be corrected by programming (38.5%). Battery depletion accounted for only 18% of malfunctions, occurring earliest in the forty-third month of follow-up. Pulse generator longevity of those devices reaching end of battery life during the study period was 68.6 +/- 16.7 months (mean + SD). We conclude that specialized pacemaker follow-up continues to be necessary despite improved pulse generator reliability and longevity. Indeed, with reprogramming, it presently plays an even more important role than in the past. Follow-up should be oriented not only to the detection of battery depletion but also toward a comprehensive surveillance of pacemaker system function.

Thoracoabdominal aortic aneurysms: preoperative and intraoperative factors determining immediate and long-term results of operations in 605 patients.

Graft inclusion and vessel reattachment to openings made in the graft were employed in the treatment of 605 patients with thoracoabdominal aortic aneurysms. These patients were divided into four groups on the basis of the extent of aneurysm. Group I consisted of those patients with involvement of most of the descending thoracic and upper abdominal aorta; group II involved most of the descending thoracic aorta and most or all of the abdominal aorta; group III involved the distal descending thoracic aorta and varying segments of abdominal aorta; and group IV involved most or all of the abdominal aorta including the segment from which the visceral vessels arose. The cause of aneurysm formation was medial degenerative disease in 80%, and dissection in 17%; other causes were responsible in the remaining 3%. The median age was 65 years and associated diseases including aneurysms involving other segments, atherosclerotic occlusive disease, heart disease, chronic obstructive pulmonary disease (COPD), hypertension, and renal insufficiency were frequent. The aneurysm was symptomatic in 70% of cases and rupture had occurred in 4% of cases. There were 54 (8.9%) early (30-day) deaths and 151 late deaths; 400 (66%) patients were still alive 3 months to 20 years after operation, including 60% at 5 years. Statistically significant pre- and intraoperative variables by univariate analysis that were predictive of increased risk of early death were advancing age, associated diseases that included COPD, renal artery occlusive disease, atherosclerotic heart disease, renal insufficiency, and long aortic clamp time. Three of these (age, clamp time, and the presence of COPD) retained significance by multivariate analysis. Variables predictive of risk of late death were age, dissection, extent of aneurysm, rupture, heart disease, cerebrovascular disease, COPD, hypertension, and poor renal function. Age, rupture, renal dysfunction, extent of aneurysm, and dissection retained their significance by multivariate analysis. Variables predictive of neurologic disturbances of the lower extremities included rupture, reattachment of intercostal and lumbar arteries, clamp time, dissection, extent and age. Rupture, reattachment of vessels, dissection, and extent of aneurysm retained significance by multivariate analysis. Thus, the risk of this complication was greatest in patients with extensive lesions (group II) with aortic dissection. The greatest risk of renal failure after operation that required dialysis was in patients who had impaired renal function before operation. Methods employed did not prevent these complications.

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 patient's 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)

Alteration of diastolic filling rate during exercise radionuclide angiography: a highly sensitive technique for detection of coronary artery disease.

Diastolic and systolic parameters of left ventricular performance were characterized from high-frequency time-activity curves obtained in 10 normal volunteers (mean age 29 +/- 4 yr), in 25 patients with normal coronary arteries, and in 50 patients with coronary artery disease (CAD) at rest and during three stages of exercise radionuclide angiography. In the normal volunteers ejection fraction was 65 +/- 5% (SD) at rest and 78 +/- 5% with exercise (p less than .001). In patients with normal coronary arteries ejection fraction was 64 +/- 5% at rest and 72 +/- 8% with exercise (p less than .0001). In patients with CAD resting ejection fraction was 60 +/- 10% and that during exercise was 61 +/- 13% (p = NS). Peak diastolic filling rate in the first half of diastole, peak systolic ejection rate, and times to peak rates and to end-systole were measured. In the normal subjects resting peak diastolic filling rate was 3.1 +/- 0.6 end-diastolic counts/sec and it increased in all subjects with exercise to 3.6 +/- 0.7 (p less than .05). In patients with normal arteries and those with CAD peak diastolic filling rate was 2.3 +/- 0.8 at rest and with exercise this parameter increased to 3.2 +/- 1.1 (p less than .001) in patients with normal arteries and fell to 1.7 +/- 0.6 in those with CAD (p less than .001). Peak systolic ejection rate decreased from 2.5 +/- 0.8 to 1.9 +/- 0.8 with exercise in patients with CAD (p less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Late repair of coarctation of the descending thoracic aorta in 190 patients. Results up to 30 years after operation.

Over a 30-year period, 190 consecutive patients had repair of coarctation of the descending thoracic aorta at a mean age of 25 years (range, 1 to 60 years); 130 were male. Median preoperative blood pressure (BP) was as follows: systolic, 160 mm Hg (range, 94 to 300 mm Hg) and diastolic, 90 mm Hg (range, 50 to 160 mm Hg). Dacron grafts were used in 64.7% of patients. Follow-up was obtained at a mean interval of 84.9 months, range, one to 360 months. Survival status was established for 86.1% (163/190) of patients. Postoperatively, the median BP was 133 mm Hg systolic (range, 90 to 195 mm Hg) and 80 mm Hg diastolic (range, 50 to 120 mm Hg). Overall, 80% of patients were either normotensive or had mild hypertension after operation. The best BP response and late survival were in patients operated on under 13 years of age. This study further confirms that early operation (below 5 years of age) is desirable. However, contrary to some previous reports, patients operated on as adolescents, despite some mild residual hypertension, had an excellent long-term prognosis. Patients over 21 years of age at operation had a high rate of persistent hypertension and experienced other serious cardiovascular complications.

Aortoiliac occlusive disease: factors influencing survival and function following reconstructive operation over a twenty-five-year period.

During a period of slightly over 25 years, 949 new patients with aortoiliac atherosclerotic occlusive disease--409 (43%) with associated distal disease--were submitted to various reconstructive operations for claudication in 719 and rest ischemic problems in 230 patients. The ages ranged from 21 to 91 years with a medial age of 59. Men outnumbered women 2.5 to 1. Associated diseases were present in 695 (75%); heart disease and diabetes were most common. The mortality rate from operation--50% of which was from heart disease--8% in first 5 years and 3% during the last 15 years. Good function, i.e., restoration of femoral pulses, leg salvage, and relief of symptoms, was achieved in 95% of cases early after treatment. Early results were best in patients with claudication and those without associated distal disease. The long-term survival rates were significant--50%, 30%, and 15% at 10, 15, and 20 years, respectively--and successful function was maintained in survivors in 79%, 70%, and 56% at the same intervals. Amputation was performed in only 23 (3%) patients with claudication and 33 (14%) with rest ischemia during the period of study. Survival, functional results, and incidence of amputation varied with the numerous factors described in detail herein.