Bypass Surgery Group Research Articles

Incidence, Predictors, Treatment, and Long-Term Prognosis of Patients With Restenosis After Drug-Eluting Stent Implantation for Unprotected Left Main Coronary Artery Disease

The aim of this study was to evaluate the incidence, predictors, and long-term outcomes of patients with in-stent restenosis (ISR) after percutaneous coronary intervention (PCI) with drug-eluting stents (DES) for unprotected left main coronary artery (LMCA) disease. Few data on the clinical course and management of patients experiencing restenosis after DES treatment for unprotected LMCA disease have appeared. Between February 2003 and November 2007, 509 consecutive patients with unprotected LMCA disease underwent DES implantation, with 402 (80.1%) undergoing routine surveillance or clinically driven angiographic follow-up. A major adverse cardiac event was defined as the composite of death, myocardial infarction (MI), or target-lesion revascularization. The overall incidence of angiographic ISR in LMCA lesions was 17.6% (71 of 402 patients, 57 with focal-type and 14 with diffuse-type ISR. Forty patients (56.3%) underwent repeated PCI, 10 (14.1%) underwent bypass surgery, and 21 (29.6%) were treated medically. During long-term follow-up (a median of 31.7 months), there were no deaths, 1 (2.2%) MI, and 6 (9.5%) repeated target-lesion revascularization cases. The incidence of major adverse cardiac event was 14.4% in the medical group, 13.6% in the repeated PCI group, and 10.0% in the bypass surgery group (p = 0.91). Multivariate analysis showed that the occurrence of DES-ISR did not affect the risk of death or MI. The incidence of ISR was 17.7% after DES stenting for LMCA. The long-term clinical prognosis of patients with DES-ISR associated with LMCA stenting might be benign, given that these patients were optimally treated with the clinical judgment of the treating physician.

Infrapopliteal Percutaneous Transluminal Angioplasty Versus Bypass Surgery as First-Line Strategies in Critical Leg Ischemia

Recently, endovascular revascularization (percutaneous transluminal angioplasty [PTA]) has challenged surgery as a method for the salvage of critically ischemic legs (CLI). Comparison of surgical and endovascular techniques in randomized controlled trials is difficult because of differences in patient characteristics. To overcome this problem, we adjusted the differences by using propensity score analysis. The study cohort comprised 1023 patients treated for CLI with 262 endovascular and 761 surgical revascularization procedures to their crural or pedal arteries. A propensity score was used for adjustment in multivariable analysis, for stratification, and for one-to-one matching. In the overall series, PTA and bypass surgery achieved similar 5-year leg salvage (75.3% vs 76.0%), survival (47.5% vs 43.3%), and amputation-free survival (37.7% vs 37.3%) rates and similar freedom from any further revascularization (77.3% vs 74.4%), whereas freedom from surgical revascularization was higher after bypass surgery (94.3% vs 86.2%, P < 0.001). In propensity-score-matched pairs, outcomes did not differ, except for freedom from surgical revascularization, which was significantly higher in the bypass surgery group (91.4% vs 85.3% at 5 years, P = 0.045). In a subgroup of patients who underwent isolated infrapopliteal revascularization, PTA was associated with better leg salvage (75.5% vs 68.0%, P = 0.042) and somewhat lower freedom from surgical revascularization (78.8% vs 85.2%, P = 0.17). This significant difference in the leg salvage rate was also observed after adjustment for propensity score (P = 0.044), but not in propensity-score-matched pairs (P = 0.12). When feasible, infrapopliteal PTA as a first-line strategy is expected to achieve similar long-term results to bypass surgery in CLI when redo surgery is actively utilized.

Late outcomes of on-pump and off-pump redo coronary artery bypass grafting

Benefits of off-pump surgery are still widely debated in the literature comparing with conventional coronary artery bypass grafting. The aim of our study was to compare the late outcomes of patients who underwent on-pump redo coronary artery bypass surgery with those who had off-pump redo coronary artery bypass surgery. Two groups of patients were compared. Group 1 consisted of 34 patients who underwent off-pump redo coronary artery bypass surgery, and Group 2 included 160 patients who underwent on-pump redo coronary artery bypass surgery. Both groups of patients were operated on by the same team of surgeons at the same time period. Groups did not differ by age, gender, functional class, preoperative myocardial infarction rate, and left ventricular function. More patients with hypertension were in the off-pump group. Significantly more grafts were performed in the on-pump group. Survival, presence of angina, reoccurrence of postoperative myocardial infarction, necessity of percutaneous transluminal coronary angioplasty and reoperations were evaluated in late follow-up period. The duration of follow-up was 3.37+/-2.15 years in the off-pump group and 3.27+/-2.36 years in the on-pump group. Survival after 6 years in the off-pump and on-pump redo coronary artery bypass surgery groups was 85.3% and 83.6%, respectively (P=0.758). Five years after redo operation, 54.9% of patients who underwent off-pump coronary artery bypass surgery and 69.3% of patients who underwent on-pump coronary artery bypass surgery had no angina (P=0.174). There were no major cardiac events (percutaneous transluminal coronary angioplasty, death, myocardial infarction, and reoperations) after 6 years in 69.7% of patients in the off-pump group and 76.9% of patients in the on-pump group (P=0.343). Five years after redo surgery, 79.4% of patients in the off-pump group and 91.9% in the on-pump group were free of percutaneous transluminal coronary angioplasty (P<0.02). There was no difference in survival despite the fact that patients in the on-pump group received more grafts than those in the off-pump group. Recurrence of angina and incidence of major cardiac events were almost equal in both the groups. Percutaneous transluminal coronary angioplasty was more frequently performed in the patients of off-pump group at late follow-up.

Effect of Roux-en-Y Gastric Bypass Surgery on the Sex Steroids and Quality of Life in Obese Men

The effect of bariatric surgery on the reproductive function of obese men is not entirely elucidated. The aim of the study was to define the effect of Roux-En-Y gastric bypass surgery on the reproductive hormones and sexual function in obese men. The cohort was followed for 2 yr at a clinical research center. Sixty-four severely obese men (22 who had gastric bypass surgery and 42 controls) participated in the study. Anthropometrics [weight, body mass index (BMI), and percentage body fat] and reproductive hormones were measured. The sexual quality of life was assessed using the Impact of Weight on the Quality Of Life-Lite questionnaire. Reproductive hormones and sexual quality of life were measured. The mean age was 48.9 +/- 1.2 yr. At baseline, mean weight was 333.0 +/- 7.1 lb, BMI was 46.2 +/- 0.9 kg/m(2), and total testosterone was 339.9 +/- 21.32 ng/dl. BMI correlated positively with estradiol and negatively with total and free testosterone. Indices of dissatisfaction with sexual quality of life correlated positively with measures of obesity. Difficult sexual performance and low sexual desire correlated negatively with free and total testosterone (r = -0.273, P = 0.038; and r = -0.267, P = 0.042, respectively). After 2 yr, the gastric bypass surgery group had a significant decrease in BMI (-16.6 +/- 1.2 vs. -0.46 +/- 0.51 kg/m(2)) and estradiol (-8.1 +/- 2.4 vs. 1.6 +/- 1.4 pg/ml) and had an increase in total testosterone (310.8 +/- 47.6 vs. 14.2 +/- 15.3 ng/dl) and free testosterone (45.2 +/- 5.1 vs. -0.4 +/- 3.0 pg/ml). Sexual quality of life was improved after gastric bypass surgery. Hormonal alterations and diminished sexual quality of life among obese men are related to degree of obesity, and both are improved after gastric bypass surgery.

Twenty-Five–Year Trends in In-Hospital and Long-Term Outcome After Percutaneous Coronary Intervention

Little is known about the impact of technological and pharmacological advances on long-term outcome after percutaneous coronary intervention in general clinical practice. We analyzed in-hospital and long-term outcome of 24,410 percutaneous coronary interventions among 18,575 unique patients who underwent percutaneous coronary intervention at Mayo Clinic over 25 years. The study population was divided into group 1 (n=3708), coronary interventions from 1979 to 1989; group 2 (n=7020), interventions from 1990 to 1996; group 3 (n=10,952), interventions from 1996 to 2003; and group 4 (n=2730), interventions from 2003 to 2004. Despite the fact that patients in groups 3 and 4 were significantly older, sicker, and had greater prevalence of comorbid conditions, heart failure, and previous revascularization than those in groups 1 and 2, procedural success in groups 3 and 4 improved significantly (94%) versus groups 2 (89%) and 1 (78%) (P<0.001). Significant reduction in in-hospital mortality (groups 4 to 1: 1.8%, 1.7%, 2.6%, 3.0%; P<0.001) and need for emergency bypass surgery (groups 4 to 1: 0.4%, 0.5%, 1.6%, 5%; P<0.001) was noted in groups 3 and 4 compared with groups 1 and 2. Better adherence to currently recommended evidence-based medications for secondary prevention was seen in the recent time periods. After adjustment, significant reduction in follow-up mortality (hazard ratio, 0.81 and 0.74 for groups 3 and 4, respectively); death or myocardial infarction (hazard ratio, 0.80 and 0.75 for groups 3 and 4, respectively); death, myocardial infarction, or revascularization (hazard ratio, 0.76 and 0.58 for groups 3 and 4, respectively) was noted in recent time periods. Despite higher-risk profiles of patients who underwent percutaneous coronary intervention in recent time periods, procedural success as well as in-hospital and long-term outcomes improved significantly over the last 25 years.

Preoperative Clinical Status but not Waiting Time Predicts In-Hospital Outcomes of Surgery in Patients with Left Main Coronary Artery Stenosis

Contoversy exists about the optimal operation time of the patients with left main coronary artery (LMCA) stenosis. We therefore, aimed to investigate the effect of waiting time on in-hospital morbidity and mortality in patients with LMCA stenosis and identify the risk factors associated with adverse cardiovascular events before and during surgery. One hundred seventy six patients with LMCA stenosis were divided into two groups according to the time period between coronary angiography and coronary artery bypass surgery (group 1: <or= 7 days, 94 patients; and group 2: > 7 days, 82 patients). Primary end points were death and major adverse cardiac event (MACE): in-hospital death, sustained ventricular tachycardia or ventricular fibrillation development, postoperative stay in the intensive care > 48 hrs and in hospital > 9 days. Demographic and clinical characteristics of patients in groups 1 and 2 were comparable. There was no difference between the two groups in terms of in-hospital morbidity, mortality and MACE. When we analyzed the differences between the patients with and without MACE, the patients who experienced MACE were older (p = 0.001), and had higher degree of LMCA stenosis (p = 0.01), higher degree of right coronary artery stenosis (p = 0.02), higher blood urea level (p = 0.003), and higher incidence of unstable angina or myocardial infarction within 2 weeks (p = 0.001). Independent risk factors for MACE were unstable angina or myocardial infarction within 2 weeks, age more than 70 years and stenosis more than 75% in the LMCA. These results suggest that preoperative clinical status but not waiting time predicts in-hospital surgical outcomes in LMCA stenosis.

ＥＣ‐ＩＣ ｂｙｐａｓｓの現状と未来〜ＪＥＴ／ＪＥＴ‐２／ＪＡＭ ｔｒｉａｌ報告

Since 1985, when the efficacy of the extracranial-intracranial (EC-IC) bypass surgery on stroke prevention was denied by the randomized multi-center trial, the number of bypass surgery for stroke prevention had drastically decreased all over the world. Recent development of quantitative cerebral blood flow (CBF) measurement, however, has made it possible to examine efficacy of bypass surgery for specific groups of cerebrovascular insufficiency.Japanese EC-IC bypass surgery trial (JET) focused on the efficacy of bypass for the stage II ischemia, and now established significantly lower recurrence rate in the bypass-surgery group than the medical treatment group. JET-2 study, now in progress, is designed to examine stroke recurrence rate on medical treatment for the stage I ischemia, classified into 4 subgroups based on cerebrovascular reserve capacity and rest CBF value, and will establish whether there is potential candidate in the stage I ischemia who benefit from bypass surgery for stroke prevention. Japan Adult Moyamoya (JAM) Trial is a multi-center randomized trial designed to answer the efficacy of bypass surgery for secondary prevention of hemorrhagic stroke in adult patients with moyamoya disease of hemorrhagic presentation. These Japanese multi-center studies will herald a new era of bypass surgery for stroke prevention after longstanding darkness since 1985.

Is the use of cardiopulmonary bypass for multivessel coronary artery bypass surgery an independent predictor of operative mortality in patients with ischemic left ventricular dysfunction?

Background Coronary artery bypass grafting for patients with ischemic left ventricular dysfunction (ILVD) remains superior to medical therapy in terms of long-term survival. Recently, off-pump coronary artery bypass surgery has been shown to be very promising in achieving functional improvements with favorable operative mortality in this challenging group of patients. The aim of this study was to assess the risk factors responsible for operative mortality in this group of patients. Methods The records of 305 consecutive ILVD patients, who underwent primary isolated coronary artery bypass grafting for multivessel disease at The National Heart and Lung Institute, Imperial College, University of London, between January 1999 and January 2002, were reviewed retrospectively. Patients were considered to have ILVD if they had a left ventricular ejection fraction of 0.30 or less on preoperative coronary angiography. One hundred six patients were operated on using the off-pump coronary artery bypass surgery technique, and 199 patients were operated on using the conventional coronary artery bypass grafting technique with cardiopulmonary bypass. Results Seven (6.6%) patients died in the off-pump coronary artery bypass surgery group, whereas 28 (14.1%) patients died in the cardiopulmonary bypass group ( p = 0.05). Univariate analysis of all the preoperative characteristics was performed to identify the potential predictors of mortality in the whole group of ILVD patients. Potential predictors of mortality included symptom status (stable/unstable), chronic obstructive airway disease, dyspnea grade III and IV on the New York Heart Association classification, intravenous nitrates, preoperative use of intraaortic balloon pump, ventricular tachycardia or ventricular fibrillation, body surface area less than 2, and cardiopulmonary bypass. Only ventricular tachycardia or ventricular fibrillation was proved to act as an independent predictor of operative mortality in this group of ILVD patients, with an odds ratio of 29.6 (95% confidence interval, 8.9 to 98). Conclusions This study showed that using cardiopulmonary bypass for multivessel coronary artery bypass grafting in patients with ILVD was not proved to act as an independent predictor of operative mortality.

The Dresden approach for complete multivessel revascularization

Background. In a prospective clinical trial, a group of patients receiving less invasive surgical procedure, including minithoracotomy in combination with cardiopulmonary bypass (group 1), was compared to a group of patients receiving conventional bypass surgery (group 2) for the treatment of coronary artery disease. Methods. Group 1 included 85 patients (71 men, 14 women, aged 39 to 82 years, median 61.1 ± 9.0 years); group 2 included 53 patients (38 men, 15 women, aged 51 to 79 years, median 62.0 ± 6.1 years). Results. There were no perioperative deaths in the whole series of patients. Time of operation was 256 ± 43 minutes in group 1 and 150.0 ± 53.6 minutes in group 2. Hospitalization was 6.0 ± 1.4 days and intensive care unit stay 1 day for both groups. Back pain assessment on postoperative day 3 showed less pain in group 1. Three-month follow-up revealed ischemia in stress electrocardiogram in 2 patients (2.5%) in group 1 and in 2 patients (4.1%) in group 2. Coronary angiograms confirmed the stress-electrocardiogram findings. Conclusions. Surgical results are equal for both techniques. Even though time of operation is longer in patients receiving less invasive procedures, intensive care unit stay and hospital stays are the same length. Early postoperative back pain is less in group 1 and combined with faster convalescence.

Combined carotid and coronary artery surgery: What have we learned after 15 years?

Optimal surgical strategy in patients with concomitant coronary and carotid artery disease is debatable. We have analysed 15-years of experience (January 1981–August 1996) with 195 consecutive patients in whom we have used two different surgical approaches. Group A consisted of 48 patients who underwent a single-stage surgical procedure, and group B (147 patents) underwent a two-stage procedure, either as carotid endarterectomy followed by coronary artery bypass surgery (group B 1, 97 patients), or as coronary artery bypass surgery followed by carotid endarterectomy (group B 2, 50 patients). Overall, there were 40 (20.5%) patients with left main coronary artery disease, 49 (25.1%) with poor left ventricular function, 128 (65.6%) with previous myocardial infarction, 134 (68.7%) were in New York Health Authority (NYHA) functional class III or IV, and bilateral carotid involvement was present in 57 patients (29.2%). Unstable angina was more frequent in groups A and B 2 ( P < 0.0001), NYHA class III–IV was more frequent in group A ( versus B 1, P = 0.001 and versus B 2, P = 0.02), low ejection fraction (EF) was more frequent in groups A and B 2 ( P < 0.0001 for both), bilateral carotid stenosis in groups A and B 1 ( P = 0.02 and P = 0.0001, respectively) and ulcerated plaque in group B 1 ( versus A, P = 0.0001). These differences dictated the surgical strategy, which resulted in different protocols for clinical and operative management. Results: Early mortality for the entire group was 4.6% ( 9 195 –6.2% in group A, 6.2% in group B 1 and 0% in group B 2, respectively P > 0.05). Serious morbidity occurred in 7.3% of patients ( 14 195 –8.3% in group A, 7.2% in group B 1 and 6% in group B, respectively P > 0.05). Univariate analysis revealed only bilateral carotid stenosis as a predictor of outcome ( P = 0.04). Follow-up was completed for 156 patients (80.0%) and averaged 84.1 ± 13.3 months (range 1–180 months). Kaplan-Meier survival estimate for the entire group was 81% and event-free survival was 76% at 5 years. Actuarial and event-free survivals were similar for all groups. Early and late outcome in these patients were influenced more by their preoperative clinical status than by the surgical strategy itself. It is therefore concluded that surgical approach should be individualized for the majority of patients.

The efficacy of bypass surgery for the patients with hemorrhagic Moyamoya disease

The efficacy of bypass surgery for the patients with hemorrhagic Moyamoya disease were studied by multi-center retrospective questionnaire study. The rebleeding rate was 28.3% (39/138 patients) in conservative treatment group and 19.1% (29/152 patients) in bypass surgery group with no significant statistical difference. It is still difficult to clarify the efficacy of bypass surgery for prevention of hemorrhagic attack.

Three-year follow-up of the argentine randomized trial of percutaneous transluminal coronary angioplasty versus coronary artery bypass surgery in multivessel disease (ERACI)

The purpose of this study was to report the 3-year follow-up results of the ERACI trial (Argentine Randomized Trial of Percutaneous Transluminal Coronary Angioplasty Versus Coronary Artery Bypass Surgery in Multivessel Disease). Although coronary angioplasty has been used with increased frequency in patients with multivessel coronary artery disease, its value, compared with bypass graft surgery, has not been established. Thus, controlled, randomized clinical trials such as the ERACI are needed. In this trial 127 patients who had multivessel coronary artery disease and clinical indication of myocardial revascularization were randomized to undergo coronary angioplasty (n = 63) or bypass surgery (n = 64). The primary end point of this study was event-free survival (survival with freedom from myocardial infarction, angina and new revascularization procedures) for both groups of patients at 1, 3 and 5 years of follow-up. Freedom from combined cardiac events (death, Q-wave myocardial infarction, angina and repeat revascularization procedures) was significantly greater for the bypass surgery group than the coronary angioplasty group (77% vs. 47%; p < 0.001). There were no differences in overall (4.7% vs. 9.5%; p = 0.5) and cardiac (4.7% vs. 4.7%; p = 1) mortality or in the frequency of myocardial infarction (7.8% vs. 7.8%; p = 0.8) between the two groups. However, patients who had bypass surgery were more frequently free of angina (79% vs. 57%; p < 0.001) and required fewer additional reinterventions (6.3% vs. 37%; p < 0.001) than patients who had coronary angioplasty. 1) Freedom from combined cardiac events at 3-year follow-up was greater in patients who had bypass surgery than in those who had coronary angioplasty. 2) The coronary angioplasty group had a higher incidence of recurrence of angina and the need for repeat revascularization procedures. 3) Cumulative cost at 3-year follow-up was greater for the bypass surgery group than for the coronary angioplasty group.

American Heart Association 68th Scientific Sessions, Anaheim, California, November 13 to 15, 1995.

Dr Elliott Antman, of Harvard Medical School and Brigham and Women’s Hospital in Boston, Massachusetts, presented the results of the Thrombolysis in Myocardial Infarction (TIMI) 9B study at a Satellite Symposium sponsored by George Washington University immediately prior to the American Heart Association Meetings in Anaheim, California, in November 1995. The TIMI 9 trial was a randomized, double-blind study conducted in 150 clinical centers that was designed to compare the efficacy and safety of intravenous heparin versus the direct-acting thrombin inhibitor hirudin in patients with acute myocardial infarction (<12 hours from onset) treated with a thrombolytic agent (streptokinase or tissue-type plasminogen activator [TPA], at the discretion of the treating physician). The TIMI 9A study (n=757) was suspended in April 1994 because of excessive bleeding in both the heparin and hirudin groups. The TIMI 9B trial was restarted in May 1994 with lower doses of both heparin and hirudin; enrollment (n=3002) continued through August 1995. The primary end point of the study was the 30-day incidence of death, myocardial infarction, congestive heart failure, and shock. At 30 days, there was no significant difference in the primary end point between heparin (11.8%) and hirudin (12.8%) and no difference in the incidence of death and myocardial infarction (9.3% in the heparin group, 9.6% in the hirudin group). Similarly, there was no significant difference in major bleeding events (including intracranial hemorrhage) between treatment groups. The TIMI 9 Investigators concluded that hirudin was equally effective as but not superior to heparin with respect to either clinical outcome or bleeding risk in patients with acute myocardial infarction receiving thrombolytic therapy. Also at the George Washington University Satellite Symposium, Dr Eugene Braunwald, of Harvard Medical School and Brigham and Women’s Hospital in Boston, presented the results of the TIMI 10A phase I trial. TIMI 10A is an …

Asymptomatic cardiac ischemia pilot (ACIP) study: Effects of coronary angioplasty and coronary artery bypass graft surgery on recurrent angina and ischemia

The Asymptomatic Cardiac Ischemia Pilot (ACIP) study showed that revascularization is more effective than medical therapy in suppressing cardiac ischemia at 12 weeks. This report compares the relative efficacy of coronary angioplasty or coronary artery bypass graft surgery in suppressing ambulatory electrocardiographic (ECG) and treadmill exercise cardiac ischemia between 2 and 3 months after revascularization in the ACIP study. Previous studies have shown that coronary angioplasty and bypass surgery relieve angina early after the procedure in a high proportion of selected patients. However, alleviation of ischemia on the ambulatory ECG and treadmill exercise test have not been adequately studied prospectively after revascularization. In patients randomly assigned to revascularization in the ACIP study, the choice of coronary angioplasty or bypass surgery was made by the clinical unit staff and the patient. Patients assigned to bypass surgery (n = 78) had more severe coronary disease (p = 0.001) and more ischemic episodes (p = 0.01) at baseline than those assigned to angioplasty (n = 92). Ambulatory ECG ischemia was no longer present 8 weeks after revascularization (12 weeks after enrollment) in 70% of the bypass surgery group versus 46% of the angioplasty group (p = 0.002). ST segment depression on the exercise ECG was no longer present in 46% of the bypass surgery group versus 23% of the angioplasty group (p = 0.005). Total exercise time in minutes on the treadmill exercise test increased by 2.4 min after bypass surgery and by 1.4 min after angioplasty (p = 0.02). Only 10% of the bypass surgery group versus 32% of the angioplasty group still reported angina in the 4 weeks before the 12-week visit (p = 0.001). Angina and ambulatory ECG ischemia are relieved in a high proportion of patients early after revascularization. However, ischemia can still be induced on the treadmill exercise test, albeit at higher levels of exercise, in many patients. Bypass surgery was superior to coronary angioplasty in suppressing cardiac ischemia despite the finding that patients who underwent bypass surgery had more severe coronary artery disease.

A comparison of intensive care unit utilization in Alberta and western Massachusetts

To analyze differences in intensive care unit (ICU) utilization between a Canadian province and a U.S. area. Retrospective data analysis of hospital discharge data and existing data from an international study of severity of illness in ICU patients. Administrative data for the province of Alberta and the four counties of western Massachusetts for the years 1990 to 1991 were used. Detailed data on consecutive ICU admissions from two Alberta hospitals, one western Massachusetts hospital, and 24 other U.S. hospitals for 3 months in 1991 were used. ICU use and hospital mortality rates were compared for 50,030 hospital admissions divided into 11 patient groups. ICU days per million population were two to three times as great in western Massachusetts as in Alberta. The primary reason was higher ICU incidence (percent of hospitalized patients treated in the ICU) rather than a difference in hospital admission rate or length of ICU stay. ICU incidence in western Massachusetts was significantly higher in ten of 11 patient groups--for the coronary bypass surgery group, there was no difference. The hospital mortality rate in western Massachusetts was similar to, or higher than, the mortality rate in Alberta. In Alberta, a much higher proportion of ICU patients received mechanical ventilation. For elective surgery patients, the ICU severity of illness was lower in western Massachusetts and in other U.S. hospitals than in Alberta. Western Massachusetts hospitalized patients are more likely to be treated in an ICU than are similar patients in Alberta. There is no evidence that the greater ICU utilization in western Massachusetts led to a lower hospital mortality rate.

731-6 Longterm Followup and Crossover 15 Years After Coronary Angioplasty: Comparison of Angioplasty and Bypass Surgery Strategies

To characterize the longterm outcome in patients who had successful coronary angioplasty (PTCA) and those who had an unsuccessful, uncomplicated procedure followed by elective bypass surgery (BYPASS) between 3/78 and 6/81, late followup was obtained in 196 (140 PTCA and 56 BYPASS) patients. Mean time to followup was 12 years (range = 13–16). There was no difference between the groups in survival (PTCA – 84.8%; BYPASS – 88.9%), late myocardial infarction (PTCA – 11.3%; BYPASS – 13.0%) or freedom from angina at latest contact (PTCA – 84.1 %; BYPASS – 87.0%). In the PTCA group, 110 (78.6%) were definitively treated with one or more PTCA procedures. In the BYPASS group, 46 (82.1%) were definitively treated with one or more bypass surgeries. Twenty (14.3%) of the PTCA group crossed over to BYPASS and 8 (14.3%) of the BYPASS group crossed over to PTCA. In conclusion, PTCA and BYPASS strategies yield comparable longterm results. Crossover rates between the two therapeutic procedures are similar. It appears that repeat procedures and crossovers are important in sustaining the beneficial results for both procedures over very long periods of time.

Effects of coronary artery bypass surgery and angioplasty on the total ischemic burden: A study of exercise testing and ambulatory ST segment monitoring

To assess the effects of standard therapeutic interventions on the total ischemic burden, 86 patients with stable angina underwent 48 hours of ambulatory ST segment monitoring and treadmill exercise testing before and at a mean of 10 weeks after coronary artery bypass surgery (CABG) (group 1, N = 46) or percutaneous transluminal coronary angioplasty (PTCA) (group 2, N = 40). There were 72 male and 14 female patients with a mean age of 56.4 years. All patients had documented coronary artery disease (24, single-vessel; 28, two-vessel; 34, three-vessel disease). Both groups were characteristically similar apart from more severe coronary artery disease ( p < 0.001) and more previous myocardial infarctions ( p < 0.05) in group 1. Groups with CABG and PTCA had significant prolongation of exercise time after intervention (group 1: 7.6 to 9.8 minutes, p < 0.0001; group 2: 8.1 to 10.0 minutes, p < 0.001), and both interventions led to a significant reduction in ischemic responses (group 1: 33 to 4, p < 0.001; group 2: 20 to 13, p < 0.05) to exercise. During a total of 7643 hours of ST segment monitoring, 253 episodes of ischemia were recorded in 3768 hours before and 44 ischemic episodes in 3875 hours after intervention (group 1, 113 episodes in 24 patients and 21 episodes in 10 patients; group 2, 140 episodes in 13 patients and 23 episodes in six patients). Both interventions reduced the mean frequency of ischemia per 24 hours (group 1: 1.24 to 0.22 episodes per 24 hours; p < 0.01; group 2: 1.9 to 0.3 episodes per 24 hours; p < 0.05). Almost 28% (N = 24) of resting electrocardiographic findings were altered as a result of intervention. Both CABG and PTCA are effective in improving exercise capacity and reducing the total ischemic burden. The paucity of transient ischemic episodes after these interventions and the frequency of alteration of the baseline electrocardiogram as a result of intervention make the use of ambulatory ST segment monitoring of questionable practical usage as an additional tool to assess the effects of revascularization and make interpretation of the ST segment more difficult in some instances.

Leucocytes and cardiopulmonary bypass: in vitro production of oxygen free radicals and trapping in the reperfused myocardium

The production of oxygen free radicals (OFR) by leucocytes was evaluated ex vivo by chemiluminescence (CL) before, during and after routine coronary artery bypass surgery (group A, n=11). The possibility of leucocyte trapping in the coronary circulation during the early reperfusion period was also investigated (group B, n=9). In group A, arterial blood samples were taken immediately before the start of surgery during anaesthesia, five minutes before and five and 30 minutes after the start of cardiopulmonary bypass (CPB), five minutes before and five and 30 minutes after the start of reperfusion of the heart, and then four and 24 hours after the end of CPB. In group B, arterial and coronary sinus blood samples were simultaneously drawn five and 30 minutes after the release of the aortic crossclamp. All blood samples were corrected for haemodilution. In group A, both CL and the level of circulating leucocytes declined during CPB. The lowest value of CL was measured 30 minutes after the start of CPB (69± 2% of baseline values) (mean±SEM). The lowest level of leucocytes was found after 30 minutes of CPB: 2.6±0.4 (109/l) vs 4.2±0.5 before surgery. Twenty-four hours after CPB, CL was increased to 170±49% and a leucocytosis was present (12.2±1.1). In group B, after five minutes of reperfusion the number of circulating leucocytes in arterial blood was 3.8±0.9 x 109/l as compared to 2.2±0.5 x 109/l in the coronary sinus (p&lt;0.0017). However, no such difference was found after 30 minutes of reperfusion. The decreased CL during CPB was probably due to in vivo activation and exhaustion of leucocytes. The postischaemic trapping of these cells may play a pathogenetic role in reperfusion injury.

Long-term outcome of unsuccessful percutaneous transluminal coronary angioplasty

We analyzed the long-term outcome of 198 patients after unsuccessful percutaneous transluminal coronary angioplasty. Forty-nine percent underwent emergency coronary artery bypass grafting surgery, 17% had elective bypass surgery, and 34% were treated medically. The in-hospital mortality rate was 4%, and myocardial infarction occurred in 36% of patients. Follow-up was completed in 100% of patients with a mean follow-up period of 35 +/- 22 months. Actuarial cardiac survival at 4 years was 97% in the emergency bypass surgery group, 100% in the elective bypass surgery group, and 86% in the medically treated group. Actuarial event-free survival (freedom from myocardial infarction, bypass surgery, coronary angioplasty, and cardiac death) at 4-year follow-up was 81% in 198 patients, 90% in the emergency bypass surgery group, 85% in the elective bypass surgery group, and 65% in the medically treated group. Results of multivariate analysis showed that emergency or elective bypass surgery after failed coronary angioplasty, normal or mildly impaired left ventricular function, and male sex were predictors of better outcome at 4 years.

Coronary angioscopy during cardiac catheterization and cardiac surgery.

Coronary angioscopy (CA) was performed in 30 patients (pts) during cardiac catheterization (Group 1) and in 11 pts during coronary bypass surgery (Group 2) using ultrathin fiberoptic angioscopes (phi 1.2-1.8 mm). For percutaneous CA (Group 1) the angioscope was introduced through a 9F guiding catheter from the femoral artery. The viewing field was cleared by flushing Ringer's solution and short-time occlusion of the coronary ostium by the guiding catheter. In Group 2 CA was performed retrogradely from the distal arteriotomy and through the bypass vein during flushing with cardioplegic solution. In Group 1 in 17/30 pts the coronary artery could be successfully examined by CA. In 13 pts the obstruction was eccentric and irregular shaped. In 2/5 pts, in whom CA was performed successfully pre and post balloon dilatation, CA after PTCA revealed an intimal rupture without clinical or angiographical signs of the intimal dissection. In Group 2 in 9/11 pts good visualization of stenoses could be achieved. At the obstruction site CA revealed thrombi in 3 pts and ulcer in 1 pts. In contrast to angiography, which estimates the lumen diameter of a segmental lesion, CA gives information about the luminal shape and the underlying substance of the obstruction (e.g. atheroma, thrombus, ulceration). The main problems in percutaneous CA are the insufficient intraluminal guidance, the insufficient depth of view of the angioscopes, and the limited examination time.