Predictors of reoperation after myocardial revascularization

Increasing surgeon experience and cumulative institutional experience drive decreasing hospital mortality after reoperative cardiac surgery

OBJECTIVE

The study objective was to identify the effects of surgeon experience and age, in the context of cumulative institutional experience, on risk-adjusted hospital mortality after cardiac reoperations.

METHODS

From 1951 to 2020, 36 surgeons performed 160,338 cardiac operations, including 32,871 reoperations. Hospital death was modeled using a novel tree-bagged, generalized varying-coefficient method with 6 variables reflecting cumulative surgeon and institutional experience up to each cardiac operation: (1) number of total and (2) reoperative cardiac operations performed by a surgeon, (3) cumulative institutional number of total and (4) reoperative cardiac operations, (5) year of surgery, and (6) surgeon age at each operation. These were adjusted for 46 patient characteristics and surgical components.

RESULTS

There were 1470 hospital deaths after cardiac reoperations (4.5%). At the institutional level, hospital death decreased exponentially and became less variable, leveling at 1.2% after approximately 14,000 cardiac reoperations. For all surgeons as a group, hospital death decreased rapidly over the first 750 reoperations and then gradually decreased with increasing experience to less than 1% after approximately 4000 reoperations. Surgeon age up to 75 years was associated with ever-decreasing hospital death.

CONCLUSIONS

Surgeon age and experience have been implicated in adverse surgical outcomes, particularly after complex cardiac operations, with young surgeons being novices and older surgeons having declining ability. However, at Cleveland Clinic, outcomes of cardiac reoperations improved with increasing primary surgeon experience, without any suggestion to mid-70s of an age cutoff. Patients were protected by the cumulative background of institutional experience that created a culture of safety and teamwork that mitigated adverse events after cardiac surgery.

Early cardiac contractility outcome of reoperative coronary artery bypass grafting using right gastroepiploic artery

BACKGROUND AND AIM OF THE STUDY

Reoperative coronary artery bypass grafting (redo CABG) still carries higher mortality and increased morbidity compared with primary CABG. In this study, we retrospectively reviewed our operative outcome of redo CABG to evaluate the impact of the left anterolateral thoracotomy approach using the right gastroepiploic artery (RGEA).

METHODS

Between 1994 and 2020, 11 patients (mean age 60.3 ± 13.1 years; nine men, two women) underwent isolated redo CABG using the RGEA via the left anterolateral thoracotomy.

RESULTS

The mean duration from the initial CABG was 128.3 ± 88.4 months. Redo CABG was performed because of graft occlusion in six patients (54.5%), graft stenosis in one patient (9.1%), and progressive disease of previously ungrafted vessels in four patients (36.4%). The total number of bypasses using RGEA (including Y-composite vein grafts) was 16 (four left anterior descending branches, two diagonal branches, five circumflex branches, five right coronary arteries). No residual graft injury, major comorbidity, or in-hospital death was observed. Changes in echocardiographic values before and after redo CABG were 210.9 ± 48.2 ml and 175.0 ± 41.4 ml in left ventricular end-diastolic volume, 130.2 ± 49.2 ml and 94.4 ± 33.0 ml in left ventricular end-systolic volume, and 45.6 ± 11.0% and 52.2 ± 10.7% in left ventricular ejection fraction, respectively. These parameters significantly improved after redo CABG.

CONCLUSIONS

Redo CABG with RGEA grafting via the left anterolateral thoracotomy approach is a safe and effective surgical procedure especially in improving cardiac contractility in patients who required revascularization.

A Practical Approach to Hybrid Coronary Revascularization

Combined surgical and percutaneous coronary revascularization, ie, hybrid coronary revascularization (HCR) consists of surgical left internal mammary artery (LIMA) bypass to the left anterior descending artery (LAD) and percutaneous revascularization of other diseased coronary arteries. Developed as a 1-stage procedure, HCR has not been widely adopted by the cardiovascular community. The recommended minimally invasive approach through a small left thoracotomy incision is technically demanding, and same-day percutaneous revascularization requires a hybrid operating room that is not available in most hospitals. In this review, we consider present HCR protocols, barriers to widespread adoption of HCR, and we give special attention to the surgical approach for the LIMA graft to the LAD and the timing of percutaneous revascularization. We conclude that grafting the LIMA to the LAD through a median sternotomy approach and delaying the percutaneous revascularization may facilitate the widespread use of HCR in patients with multivessel coronary artery disease and a low to intermediate Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery score.

Repeat Coronary Artery Bypass Grafting: A Meta-Analysis of Off-Pump versus On-Pump Techniques in a Large Cohort of Patients

BACKGROUND

Redo coronary artery bypass grafting (CABG) can be performed with either the off-pump (OPCAB) or the on-pump (ONCAB) technique.

METHOD

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), this meta-analysis compared the safety and efficacy of OPCAB versus ONCAB redo CABG.

RESULTS

Twenty-three (23) eligible studies were included (OPCAB, n=2,085; ONCAB, n=3,245). Off-pump CABG significantly reduced the risk of perioperative death (defined as in-hospital or 30-day death rate), myocardial infarction, atrial fibrillation, and acute kidney injury. The two treatment approaches were comparable regarding 30-day stroke and late all-cause mortality.

CONCLUSIONS

Off-pump redo CABG resulted in lower perioperative death and periprocedural complication rates. No difference was observed in perioperative stroke rates and long-term survival between the two techniques.

[Complete myocardial revascularization in patients with multiple-vessel coronary artery disease and partial or complete absence of the grafts for coronary artery bypass surgery]

Complete revascularization in patients with multiple-vessel coronary artery disease and partial or complete absence of the grafts is still actual problem for cardiac surgeons. The main causes of the absence of conduits for coronary artery bypass surgery are aging of population, increased incidence of repeated coronary artery bypass surgery and prevalence of varicose vein disease of the lower extremities. The most perspective approaches characterized by acceptable early and long-term postoperative outcomes are bilateral internal mammary artery grafting, sequential bypass including autoarterial grafts, as well as hybrid revascularization methods. However, treatment strategy is individualized in each patient.

Contemporary use of arterial and venous conduits in coronary artery bypass grafting: anatomical, functional and clinical aspects

Although the benefits of using the left internal mammary artery to bypass the left anterior descending artery (LAD) have been extensively ascertained, freedom from major cardiovascular events and survival after coronary artery bypass grafting (CABG) also correlate with the completeness of revascularisation. Hence, careful selection of the second-best graft conduit is crucial for CABG success. The more widespread use of saphenous vein grafts contrasts with the well-known long-term efficacy of multiple arterial grafting, which struggles to emerge as the procedure of choice due to concerns over increased technical difficulties and higher risk of postoperative complications. Conduit choice is at the discretion of the operator instead of being discussed by the heart team, where cardiologists are not usually engaged in such decisions due to a hypothetical lack of technical knowledge. Furthermore, according to the ESC/EACTS guidelines, traditional CABG remains the gold standard for multi-vessel coronary artery disease with complex LAD stenosis, but hybrid procedures using percutaneous coronary intervention for non-LAD targets could combine the best of two worlds. With the aim of raising the cardiologist's awareness of the surgical treatment options, we provide a comprehensive overview of the anatomical, functional and clinical aspects guiding the decision-making process in CABG strategy.

Experience with Bilateral Internal Mammary Artery Grafts for Myocardial Revascularization in Asian Patients

Bilateral internal mammary artery grafts were used for direct myocardial revascularisation in 72 patients from August 1988 to January 1994. Twenty-five of them had diffuse coronary artery disease. The coronary arteries were small in the majority of patients and 10 patients needed endarterectomy. Two patients died in the hospital. Fifty-nine patients were followed up and the mean time of follow-up was 25 months. One patient died during the follow-up period and another patient developed inferior wall myocardial infarction. Three patients are on antianginal medications and the rest are doing well.

Protective effects of panax notoginseng saponins on cardiovascular diseases: a comprehensive overview of experimental studies

Panax notoginseng saponins (PNS) are one of the most important compounds derived from roots of the herb Panax notoginseng which are traditionally used as a hemostatic medicine to control internal and external bleeding in China for thousands of years. To date, at least twenty saponins were identified and some of them including notoginsenoside R1, ginsenoside Rb1, and ginsenoside Rg1 were researched frequently in the area of cardiovascular protection. However, the protective effects of PNS on cardiovascular diseases based on experimental studies and its underlying mechanisms have not been reviewed systematically. This paper reviewed the pharmacology of PNS and its monomers Rb1, Rg1, and R1 in the treatment for cardiovascular diseases.

Long-term outcomes of percutaneous coronary interventions with stent implantation in patients ≤40 years old

Data on the long-term prognosis of percutaneous coronary intervention (PCI) in young patients are limited. The aim of the present study was to report the immediate and long-term clinical outcomes in a consecutive series of young patients with premature coronary artery disease who underwent PCI with stent implantation. During the study period (2005 to 2010), 214 consecutive patients aged ≤40 years who had undergone PCI with a bare metal stent or drug-eluting stent implantation were retrospectively selected and analyzed. Primary end point of this study was the incidence of major adverse cardiac and cerebrovascular events at short- and long-term follow-up. Mean age was 36.3 ± 3.5 years and 88.3% of patients were men. Three-quarters were active smokers and all patients had ≥1 conventional cardiovascular risk factor. The total number of implanted stents was 272 (154 bare metal stent and 118 drug-eluting stent). During the hospital stay, no patient died, and the incidence of major adverse cardiac and cerebrovascular events was 2.3%. No additional events had occurred at 30 days of follow-up. At a median follow-up of 757 days (interquartile range 365 to 1,818), the overall death rate was 0.9%, and a new revascularization procedure was needed in 12.6% of patients. The major adverse cardiac and cerebrovascular event-free survival rate at the median follow-up point and 1,818 days was 89.6% and 84.2%, respectively. Active smoking and left ventricular ejection fraction <50% were independent predictors of major adverse cardiac and cerebrovascular events. In conclusion, PCI in young patients lead to excellent results in short- and long-term follow-up and should be considered as the treatment of choice. Traditional risk factors are important prognostic determinants of adverse events and might help identify higher risk patients within this cohort.

Metabolic profiles predict adverse events after coronary artery bypass grafting

OBJECTIVE

Clinical models incompletely predict the outcomes after coronary artery bypass grafting. Novel molecular technologies can identify biomarkers to improve risk stratification. We examined whether metabolic profiles can predict adverse events in patients undergoing coronary artery bypass grafting.

METHODS

The study population comprised 478 subjects from the CATHGEN biorepository of patients referred for cardiac catheterization who underwent coronary artery bypass grafting after enrollment. Targeted mass spectrometry-based profiling of 69 metabolites was performed in frozen, fasting plasma samples collected before surgery. Principal components analysis and Cox proportional hazards regression modeling were used to assess the relation between the metabolite factor levels and a composite outcome of postcoronary artery bypass grafting myocardial infarction, the need for percutaneous coronary intervention, repeat coronary artery bypass grafting, and death.

RESULTS

During a mean follow-up period of 4.3 ± 2.4 years, 126 subjects (26.4%) experienced an adverse event. Three principal components analysis-derived factors were significantly associated with an adverse outcome on univariate analysis: short-chain dicarboxylacylcarnitines (factor 2, P = .001); ketone-related metabolites (factor 5, P = .02); and short-chain acylcarnitines (factor 6, P = .004). These 3 factors remained independently predictive of an adverse outcome after multivariate adjustment: factor 2 (adjusted hazard ratio, 1.23; 95% confidence interval, 1.10-1.38; P < .001), factor 5 (odds ratio, 1.17; 95% confidence interval, 1.01-1.37; P = .04), and factor 6 (odds ratio, 1.14; 95% confidence interval, 1.02-1.27; P = .03).

CONCLUSIONS

Metabolic profiles are independently associated with adverse outcomes after coronary artery bypass grafting. These profiles might represent novel biomarkers of risk that can augment existing tools for risk stratification of coronary artery bypass grafting patients and might elucidate novel biochemical pathways that mediate risk.

The Radial Artery in Reoperative Coronary Bypass Surgery:. A 5-Year Experience

BACKGROUND

Failure of saphenous vein grafts (SVG) is a significant cause for coronary reoperation (redo CABG). The radial artery (RA) because of its availability, and versatility is well suited to use (together with internal thoracic arteries (ITA) in redo CABG, especially to replace failed SVG. We evaluated our experience where the RA was a major conduit in redo CABG over the past 5 years.

METHODS

From July 1996 to June 2002, 590 consecutive patients underwent redo CABG where one or both RA(s) were used, together with LITA or RITA. The mean age was 67.3 years, 82% were male, and 19% diabetic, 419 (71%) had Class III or IV angina, 135 (23%) had left main stenosis, and 210 (36%) had an LVEF < 0.50. There were a total of 877 RA conduits (303 single, 287 bilateral), 518 new LITA or RITA. A mean of 2.8 new distal anastomoses constructed 92% (2.6 per patient)of the arterial grafts. Follow-up was at 1 month, 3 months, and then yearly. The results were compared with 6466 primary CABG performed in the same time frame, and with a prior cohort of 741 consecutive patients having redo CABG without an RA in which identical operative techniques had otherwise been used.

RESULTS

The 30-day mortality was 3.9% (23 patients). Morbidity was low. Perioperative myocardial infarction occurred in 16 (2.7%) patients, stroke in 10 (1.7%), sternal infection in 10 (1.7%), donor site infection in 2 (0.3%), and IABP use in 23 patients (3.9%)-including 10 preoperatively. The results were better when compared to a prior cohort of 741 patients with redo CABG (1991 to 1996) without use of the RA. The results were inferior to that of the contemporary primary CABG. Operative mortality was 3.9% versus 0.9%, p = 0.002, myocardial infarction 2.7% versus 0.8%, p = 0.03.

CONCLUSION

The use of the RA (together with ITA) in redo CABG achieved total arterial revascularization in 92% of cases and is associated with excellent results, at least equal to or superior to those achieved previously.

Transmyocardial Laser Therapy: A Strategic Approach

BACKGROUND

Coronary artery bypass and percutaneous intervention have become the established methods of coronary revascularization in treating angina pectoris. Subsets of angina patients, however, are not amenable to either of these procedures. Transmyocardial laser revascularization (TMR) has been developed as a potential treatment to address such patients, and clinical research to date illustrates the success of TMR for this patient group.

STRATEGIC PLAN SUMMARY

Although the symptoms of ischemic heart disease manifest themselves in a variety of ways, the best results with TMR are seen in patients with severe angina rather than in patients with silent ischemia or congestive heart failure. Potential TMR patients receive diagnostic tests to determine if and where the therapy should be applied. A recent cardiac catheterization is required to document the status of and the coronary-system suitability for the planned intervention. It is not appropriate to assume that a patient with nonbypassable, noninterventional coronary artery disease has to be relegated to medical therapy only. Additionally, echocardiography demonstrates the status of cardiac valves and segmental wall motion activity. This knowledge allows the surgeon to determine the sequence of surgery and if abnormalities are present. Once the decision to use TMR use has been made, there are 2 approaches--sole therapy or adjunctive therapy. TMR is not to be substituted for a feasible bypass graft, but the best time to make this decision may well be during the surgery itself, because grafts that appear surgically feasible on an angiogram may be less feasible after the chest has been opened. The decision to perform sole-therapy TMR in the absence of bypassable vessels clearly must be made before opening the chest. Whether to use cardiopulmonary bypass (CPB) and the sequence in which to perform TMR and bypass grafts are based on surgeon preference. The advantage of performing TMR on CPB is that channels can quickly be lased without pause. A potential advantage of performing TMR before bypass grafts is that "channel leak" (bleeding) can be minimized by the conclusion of the surgery. Complete revascularization has become technically more difficult because of the increasing use of percutaneous approaches and because patients are being referred for coronary artery bypass grafting much later in the course of their coronary disease progression than before. TMR may well be a viable alternative to bypassing a heavily diseased, previously intervened, small-diameter coronary artery. Thus, a model in which myocardial perfusion is considered within the context of the natural circulation can be conceived as an alternative to a model in which circulation is altered by interventional, surgical, and/or transmyocardial methods. TMR has been shown to be effective in accomplishing a complete revascularization when the restoration of circulation to ischemic territories with interventional therapy, bypass surgery, or a combination of both has been ineffective. We recommend that interested users follow this "complete revascularization strategy" algorithm for all ischemic vessels being considered for interventional or surgical treatment. Running each diseased vessel through this thought process will ensure that available treatment options are considered in the optimization of a patient's outcome.

CONCLUSION

The use of TMR for angina relief has evolved into a clinically proven technology that has enabled physicians to address difficult revascularization cases with a therapy that is safe and effective.

Redo coronary artery bypass grafting: early and mid-term results

OBJECTIVES

Redo coronary artery bypass grafting (CABG) has been gradually increasing in Japan. We prospectively collected redo-CABG data and evaluated these the early and remote results.

METHODS

Between 01/01/1994 and 06/30/2002, a total of 71 patients underwent isolated redo-CABG in our hospital group. The interval between operations was 7.8 +/- 6.1 years. Previous surgery was CABG in all patients. Perioperative, early angiographic, and follow-up results were analyzed.

RESULTS

The mean number of grafts was 2.9 +/- 1.2. There were 4 incidences of injury to the heart or graft during sternal re-entry or during dissection of the heart. There was 1 hospital death (2.8%) and 19 major complications (26.8%), including 7 patients (9.9%) with postoperative congestive heart failure and 2 (2.8%) with postoperative myocardial infarction. Postoperative angiography was obtained in 47 patients and their overall stenosis free patency rate was 93.9%. Follow-up was completed for all hospital survivors with a mean follow-up of 3.9 +/- 2.2 years. The event-free and survival rates at 5 years were 76.4% and 83.9%, respectively.

CONCLUSION

In our limited experience, redo-CABG was performed with acceptable risks and its long-term results were satisfactory.

Results of bioprosthetic versus mechanical aortic valve replacement performed with concomitant coronary artery bypass grafting

BACKGROUND

Concomitant coronary artery disease with aortic valve disease is an established risk factor for diminished late survival. This study evaluated the results of bioprosthetic (BAVR) or mechanical aortic valve replacement (MAVR) performed with coronary artery bypass grafting (CABG).

METHODS

From January 1984 through July 1997, combined AVR + CABG was performed in 750 consecutive patients; 469 received BAVR and 281 received MAVR. BAVR recipients were significantly older (mean age, 75 vs 65 years), and had more nonelective operations, congestive heart failure, peripheral vascular disease, preoperative intraaortic balloons, lower cardiac indices, more severe aortic stenosis, less aortic regurgitation, and more extensive coronary artery disease.

RESULTS

Early complications included operative mortality, 32 patients (4.3% total: 3.8% BAVR and 5.0% MAVR); perioperative infarction, 10 (1.3%); and perioperative stroke, 22 (2.9%). Significant multivariable predictors of early mortality were age, perioperative infarction or stroke, nonelective operation, operative year, ventricular hypertrophy, and need for intraaortic balloon. Ten-year actuarial survival was 41.7% for all patients. Predicted survival for age- and gender-matched cohorts from the general population versus observed survival were BAVR, 45% versus 36%; MAVR, 71% versus 48% (survival differences BAVR 9% vs MAVR 23%, p < 0.007). Significant multivariable predictors of late mortality included age, congestive failure, perioperative stroke, extent of coronary disease, peripheral vascular disease, and diabetes. Valve type was not significant. Ten-year actuarial freedom from valve-related complications were (BAVR vs MAVR) structural deterioration, 95% versus 100%, p = NS; thromboembolism, 86% versus 84%, p = NS; anticoagulant bleeding, 93% versus 88%, p < 0.005; reoperation, 98% versus 98%, p = NS.

CONCLUSIONS

AVR + CABG has diminished late survival despite the type of prosthesis inserted. Although valve type did not predict late mortality, mechanical AVR was associated with worse survival compared with predicted and more valve-related complications due to anticoagulation requirements.

Does coronary endarterectomy increase the risk of coronary bypass?

BACKGROUND

With increased incidence of angioplasty and stent implantation, patients referred for coronary bypass (CABG) typically have more advanced and diffuse coronary disease. Thus, more patients may require endarterectomy in order to achieve complete revascularization. We compared our results in patients undergoing CABG with or without coronary endarterectomy.

METHODS

Between 1993 and 1999, 2372 patients underwent isolated CABG in our department. A retrospective analysis was performed to compare patients requiring coronary endarterectomy of the LAD (group 1, n = 88), endarterectomy of arteries other than the LAD (group 2, n = 143), to those not requiring endarterectomy (group 3, n = 2071). Patients undergoing CABG without the use of cardiopulmonary bypass were excluded. Group 1 had a higher incidence of proximal LAD stenosis (p = 0.001) than group 3, while group 2 had a higher incidence of peripheral vascular disease (p = 0.02), preoperative MI (p = 0.03) and LV dysfunction (p = 0.001).

RESULTS

Operative mortality was 10% in group 1 (p < 0.001) and 4% in group 2 (p = NS) compared to 3% in group 3. Incidence of perioperative MI was 12% in group 1 (p = 0.001) and 8% in group 2 (p = 0.001) compared to 2% in group 3.

CONCLUSIONS

Patients requiring endarterectomy of the LAD are at increased risk of operative mortality. This was not true for patients requiring endarterectomy of arteries other than the LAD. In both groups there was an increased risk of perioperative myocardial infarction.

Alternatives to traditional coronary bypass surgery

Over 1 million percutaneous coronary interventions (PCI) and a half million surgical coronary artery bypass grafting procedures (CABG) are performed in the United States annually for treatment of coronary artery disease. With recent advances in anti-restenosis strategies, the number of PCIs is expected to increase dramatically. Still, these therapies treat relatively discrete coronary lesions. However, there is a relatively large number of patients for whom traditional therapies are not optimal, either because there are diffuse coronary artery lesions, because there are chronic total occlusions, or because, in the instance of bypass surgery, creating proximal or distal anastomoses is problematic. We review three strategies in various stages of development aimed at treating patients not optimally served by traditional forms of revascularization: transmyocardial laser revascularization, angiogenic therapies, and direct ventricle-to-coronary artery bypass.

Angiogenesis by endothelial cell transplantation

PURPOSE

Myocardial angiogenesis may improve regional perfusion and perhaps function after cardiac injury. We evaluated the effect of endothelial cell transplantation into a myocardial scar on angiogenesis and ventricular function, as an alternative to angiogenic gene or protein therapy.

METHODS AND RESULTS

A transmural myocardial scar was created in the left ventricular free wall of rat hearts by cryoinjury. Allogeneic aortic endothelial cells were injected into the scar 2 weeks after cryoinjury. A cluster of transplanted cells was identified at the site of injection 1 day and 1 week after transplantation, but not after 2 weeks. The size of this cluster of transplanted cells decreased as vascular density in the transplanted scar tissue increased with time. Six weeks after transplantation, vascular density was significantly greater in transplanted hearts than in control hearts. Regional blood flow, by microsphere analysis, was greater in the transplanted rats. Systolic and diastolic ventricular function was similar between groups. In a second series of experiments, syngeneic aortic endothelial cells labeled with bromodeoxyuridine were transplanted 2 weeks after cryoinjury. Vascular density in the transplanted scar was greater than in controls. Labeled transplanted endothelial cells were identified forming part of the newly developed blood vessels. No difference in vascular density was found between allogeneic and syngeneic cell transplantation. Vascular endothelial growth factor was not expressed at greater levels in the transplanted cells or the myocardial scar.

CONCLUSION

Transplanted endothelial cells stimulated angiogenesis, were incorporated into the new vessels, and increased regional perfusion in myocardial scar tissue, but did not improve global function in this cryoinjury rat model.

[Clinical results of double versus single mammary artery myocardiac revascularization: 15 years of follow-up]

INTRODUCTION

Use of the left internal mammary artery to bypass the left anterior descending coronary artery reduces cardiac events and increases survival. However, there is some controversy as to the benefits of using both mammary arteries.

OBJECTIVES

To assess the long-term outcome of the use of both mammary arteries in comparison with the use of only one.

PATIENTS AND METHOD

A retrospective cohort study with a mean follow-up of 9.0 +/- 4.2 years was performed including 108 patients consecutively revascularized using both mammary arteries (II) and 108 patients randomly chosen in whom one mammary artery (I) was used for this purpose.

RESULTS

Both groups were similar. There were no differences between the groups in operative morbidity or mortality. The survival at 10 years was similar (II: 84.61 +/- 4%; I: 85.18 +/- 3.8%), whereas recurrence of angina (II: 29.63 +/- 5.3%; I: 47.55 +/- 5.6%) (p = 0.012), the requirement for percutaneous angioplasty (II: 3.98 +/- 2%; I: 12.99 +/- 4.1%) (p = 0.009) and cardiologic events (II: 33.48 +/- 5.5%; I: 48.48 +/- 5.5%)(p = 0.022) were all lower in the group in which both mammary arteries were used. In the multivariate analysis, the use of both mammary arteries was an independent protective factor against angina recurrence (RR = 0.55), angioplasty (RR = 0.18) and cardiologic event (RR = 0.60).

CONCLUSIONS

The use of both mammary arteries for revascularization does not increase operative morbidity. Since this procedure acts as an independent factor against angina recurrence, angioplasty and cardiologic event

The radial artery in coronary re-operations

OBJECTIVES

Vein graft (VG) failure often leads to coronary re-operation (re-do coronary artery bypass grafting (CABG)). As the internal thoracic artery (ITA(s)) and VG have often already been used and as the VG has usually failed, the radial artery (RA) is ideally suited for use in re-do CABG. We evaluated our experience where the RA(s) was a key conduit in re-do CABG to determine the safety and efficacy and compared this to re-operations where the RA was not used.

METHODS

Three hundred and fifty-two consecutive patients who had re-do CABG using the RA(s) from July 1995 to March 1999 were studied: mean age 67.3 years, 209 (60%) angina Class III or IV, past acute myocardial infarction (AMI) in 201 (57%), left ventricular ejection fraction <50% in 109 (31%). Five hundred and thirty-two RAs were used (bilateral in 180 (51%) patients). Additionally, 232 new left ITAs (66% of patients) and 71 new right ITAs (20% of patients) were placed. A total of 1022 distal anastomoses were performed (mean of 2.9 per patient). Follow-up was at 1 month, 3 months, and yearly. The results were also compared to 730 patients having re-do CABG without an RA (January 1990 to June 1995) using identical operative and myocardial protection techniques.

RESULTS

RA spasm was noted intra-operatively in four (1.1%) patients, operative mortality was noted in 14 (3.9%) patients, peri-operative myocardial infarction was noted in ten (2.8%) patients, intra-aortic balloon pump was used in nine (2.6%) patients, stroke was noted in six (1.7%) patients, deep sternal infection was noted in two (0.6%) patients, and re-operation for haemorrhage was performed in seven (2.0%) patients. There was only one (0.3%) forearm infection, and two (0.6%) forearm haematomas required drainage. There was no hand ischaemia. When compared to 730 re-do CABG patients without RA, there were significant differences in arterial grafts used (2.6 vs. 1.2, P=0.01), in deep sternal infection (0.6% vs. 2.6%, P=0.01) and donor site infection (0.3% vs. 2.7%, P=0.005) favouring the RA group. Three-year actuarial survival was 89.2% in the RA group and 88.5% in the non-RA group (P=1.0).

CONCLUSIONS

Use of the RA in re-do CABG is safe, effective, allows additional conduit choice, reduces donor site and sternal infections, and may avoid further late VG failure.

Direct coronary artery perfusion from the left ventricle

OBJECTIVES

Trends in coronary bypass surgery require less invasive techniques and more conduits. We investigated the ability of direct coronary perfusion from the left ventricle to support regional and global cardiac function.

METHODS

A conduit was established between the left ventricle and left anterior descending coronary artery (n = 6) with an interposed Starling resistor that allowed for graded regulation of backward flow. Changes of coronary flow, regional function in the territory of the left anterior descending coronary artery, and reactive hyperemia were studied. In 3 separate dogs, functional tolerance to increased heart rate was tested. In another 3 dogs, left ventricle-left anterior descending and left ventricle-left circumflex coronary artery conduits were established simultaneously (double conduit), and global function was tested.

RESULTS

Without flow regulation, flow through the left ventricle-left anterior descending conduit exhibited high peaking (102 +/- 35 mL/min), midsystolic forward flow, and large pandiastolic backward flow (peaking at -47 +/- 22 mL/min). Mean coronary flow and regional function were maintained at 46.0% +/- 7.1% (35.8%-54.2%) and 45.3% +/- 29.1% (-1.8%-74.2%) of their respective normal values. When the Starling resistor was used to regulate backward flow, these values increased to 70.8% +/- 12.5% (56.8%-90.4%) and 70.2% +/- 27.8% (23.6%-107.7%), respectively. Coronary and functional reserve with a left ventricle-left anterior descending conduit were not observed. With the double conduit, global ventricular contractility indexed by end-systolic pressure-volume relation averaged 46% +/- 35% of its normal value.

CONCLUSIONS

A left ventricle-coronary artery conduit supplied approximately 45% of normal blood flow and regional function, and both were improved by regulation of backward flow. Therefore, a conduit from the left ventricle to an epicardial vessel could serve as a rapidly deployable means of revascularizing totally occluded coronary vessels for which suitable natural conduits are not available.

Reoperative coronary bypass surgery: effect of patent grafts and retrograde cardioplegia

OBJECTIVE

To determine the effects of patent or diseased aorta-coronary bypass grafts and retrograde cardioplegia on mortality during reoperative coronary bypass surgery.

METHODS

We conducted a retrospective review of prospectively gathered data, supplemented by systematic chart review, of all patients (n = 744) undergoing reoperative coronary bypass surgery at our institution between 1990 and 1997. Independent predictors of survival were determined by stepwise logistic regression analysis.

RESULTS

At least one patent or stenosed graft to the left anterior descending artery was present in 50% of patients, to the circumflex territory in 27% of patients, and to the right coronary artery territory in 33% of patients. The previous left anterior descending graft was a saphenous vein in 82% and a left internal thoracic artery in 18% of patients. In-hospital mortality occurred in 42 (5.6%) patients. Patent or diseased grafts of any coronary artery territory did not significantly increase the risk of mortality. Retrograde cardioplegia use increased in more recent years, was more frequent in patients with stenosed grafts, and was associated with improved survival. Independent predictors of mortality were as follows (with odds ratios and 95% confidence intervals in parentheses): failure to use retrograde cardioplegia (odds ratio 2.81; 1.28-6.20), New York Heart Association class (odds ratio 2.69; 1.25-5.81), peripheral vascular disease (odds ratio 2.60; 1.25-5.41), and left ventricular grade (2.07; 1.31-3.27).

CONCLUSIONS

In this series, patent or stenosed grafts were not associated with an increased risk of mortality during reoperative coronary bypass surgery, possibly because of increased use of retrograde cardioplegia in this patient group. We strongly recommend the routine use of retrograde cardioplegia during redo coronary bypass surgery.

Prognostic factors for atherosclerosis progression in saphenous vein grafts: the postcoronary artery bypass graft (Post-CABG) trial. Post-CABG Trial Investigators

OBJECTIVES

The study was done to assess patients in the Post-Coronary Artery Bypass Graft (Post-CABG) trial to determine prognostic factors for atherosclerosis progression.

BACKGROUND

Saphenous vein grafts (SVGs) are effective in relieving angina and, in certain patient subsets, in prolonging life. However, the progression of atherosclerosis in many of these grafts limits their usefulness.

METHODS

The Post-CABG trial studied moderate versus aggressive lipid-lowering and low-dose warfarin versus placebo in patients with a history of coronary artery bypass surgery and found that more aggressive lipid lowering was effective in preventing progression of atherosclerosis in SVGs, but warfarin had no effect. Using variables measured at baseline, we sought the independent prognostic factors for atherosclerosis progression in SVGs, employing the statistical method of generalized estimating equations with a logit-link function.

RESULTS

Twelve independent prognostic factors for atherosclerosis progression were found. In the order of their importance they were: maximum stenosis of the graft at baseline angiography, years post-SVG placement; the moderate low-density lipoprotein-cholesterol (LDL-C) lowering strategy; prior myocardial infarction; high triglyceride level; small minimum graft diameter; low high-density lipoprotein-cholesterol (HDL-C); high LDL-C; high mean arterial pressure; low ejection fraction; male gender; and current smoking.

CONCLUSIONS

This study identified Post-CABG patient and SVG characteristics associated with saphenous vein graft atherosclerosis progression. These data provide a basis for rational risk factor management to prevent progression of SVG atherosclerosis.

Coronary artery reconstruction for extensive coronary disease: 108 patients and two year follow-up

BACKGROUND

Surgical coronary artery reconstruction for diffuse coronary disease is described and assessed.

METHODS

A long arteriotomy, internal thoracic artery graft, and exclusion of atheromatous plaques from the coronary lumen are the bases of the technique. One hundred eighteen reconstructions were performed in 108 patients with a mean age of 59 years. Stable angina was present in 62% of patients and unstable angina in 22%. Sixteen percent had had a recent myocardial infarction. The reconstructions involved 94 left anterior descending coronary arteries, 17 marginal, 5 diagonal, and 2 right coronary arteries.

RESULTS

The perioperative mortality rate was 3.7% (4 patients). The rate of perioperative myocardial infarction was 6.3%. Mean follow-up was 29 months (standard deviation, 10 months). Two patients were lost to follow-up. Ninety patients were free from angina and cardiac-related events. Five patients sustained a myocardial infarction, 3 were in congestive heart failure, 3 had class II angina, and 1 died of stroke. Seventy-four of the surgical coronary artery reconstructions have been angiographically evaluated (29 months): 94.6% of the internal thoracic artery grafts were completely patent, and 70 of the reconstructions were patent without restenosis. String signs and occlusions were present in two internal thoracic arteries each.

CONCLUSIONS

This technique allows revascularization of severely and diffusely diseased coronary arteries with encouraging results.

Is diabetes mellitus a major risk factor in coronary artery bypass grafting? The influence of internal thoracic artery grafting on late survival in diabetic patients

OBJECTIVE

The presence of diabetes could possibly have an adverse influence on the late results of coronary artery bypass grafting (CABG). A retrospective observational risk-unadjusted estimation study was conducted to clarify the magnitude of this unfavorable influence of diabetes based on our experience at Juntendo University.

METHODS

Between January 1984 and December 1995, 1,618 primary CABG operations were performed and 99.0% of these patients were followed up for a mean period of 81.2 months with a maximal follow-up of 14 years. Among the 1,610 patients who were successfully followed up, 523 patients (32.5%) were diabetic and this cohort was compared with 1,087 nondiabetic patients regarding the patient profiles, perioperative outcome, and the long-term outcome.

RESULTS

Diabetic patients included a higher proportion of females, a greater preoperative presence of renal insufficiency, a higher rate of three vessel disease, and reception of a greater number of grafts (mean: 2.5 versus 2.4) and an internal thoracic artery graft (68% versus 58%). Hospital mortality was not significantly different (2.1% vs 1.0%: ns). An actuarial analysis revealed a significantly unfavorable long-term survival in the diabetic group (59.6%) at 14 years, compared with the nondiabetic group (73.4%), however diabetic patients with an internal thoracic artery graft had a favorable long-term survival (82.0%) at 13 years, and this finding was almost identical to that of nondiabetic patients with an internal thoracic artery graft (88.5%).

CONCLUSION

We conclude that the presence of diabetes appears to be a major risk factor in patients undergoing CABG. However, diabetic patients with an internal thoracic artery graft had a survival almost identical to that of nondiabetic patients with an internal thoracic artery graft.

Functional assessment of disease-free saphenous vein grafts at redo coronary artery bypass grafting

BACKGROUND

Reoperations for coronary artery bypass grafting are on the rise. The general rule of replacing all saphenous vein grafts (SVGs) older than 5 years of age at the time of reoperation has recently been challenged on clinical grounds. This study provides functional data of endothelial behavior in long-term vein grafts.

METHODS

Previously placed SVGs were removed at the time of redo operations. Nitric oxide (NO) measurements in real time were carried out before and after stimulation with morphine. The measurements were compared to the angiographic appearance of the grafts obtained prior to operation. Grafts were categorized into 3 groups: disease-free, moderately diseased, and severely diseased.

RESULTS

Sixteen grafts were analyzed. Five were angiographically disease-free, 4 had moderate, and 7 severe disease. In the disease-free group, peak NO production after 10(-6) mol/L morphine stimulation was 35 mol/L, equivalent to the production of native saphenous vein. The severely diseased group did not demonstrate an increase in NO production, and the moderately diseased group produced a small rise in production.

CONCLUSIONS

Measurement of NO release of old SVGs, when angiographically pristine, equals that of native saphenous vein. These findings support the recent clinical observations that long-term angiographically disease-free vein grafts are biologically privileged.

Multiple arterial grafts and survival

Limitations in the long-term patency of saphenous veins for bypass grafts have encouraged interest in the use of arterial conduits. The positive effect of an internal thoracic artery graft on survival has been accepted for more than a decade, but it has proven difficult to show additional benefit from additional arterial conduits; this is probably due to multiple factors, including inappropriate choice of target vessels, short follow-up, and inadequate numbers of patients. Recently, however, the positive effect of a second arterial graft was confirmed. It will probably be difficult to show a survival benefit from a third or fourth arterial graft, but we believe that complete arterial revascularization will result in improved long-term freedom from reintervention. Interest in arterial conduits for coronary artery bypass was primarily limited to the left internal thoracic artery until the mid-1980s, when enthusiasm for the use of bilateral internal thoracic arteries grew. More recently, the gastroepiploic artery, the inferior epigastric artery, and especially the radial artery have all found advocates. However, the original conduit--and the standard against which all others are compared--is the greater saphenous vein.

Total arterial revascularization with an internal thoracic artery and radial artery T graft

BACKGROUND

Proximal anastomosis of the radial artery to the side of the internal thoracic artery (ITA) permits complete arterial revascularization in most patients, with the aim of improving long-term results of coronary artery bypass through greater long-term graft patency. The short-term results, however, have yet to be defined. We therefore reviewed our early experience with this grafting strategy.

METHODS

Between October 1, 1993, and September 1, 1998, 649 patients aged 30 to 85 years (mean, 60+/-10 years) had primary coronary artery bypass using an ITA and radial artery in a T-graft configuration. Left ventricular function was severely depressed (ejection fraction <35%) in 12%, and left main stenosis was present in 14%.

RESULTS

A total of 937 distal anastomoses were performed with the left ITA (1.4 per patient) and 1,452 with the radial artery (2.2 per patient). There was one perioperative death (0.2%). There were 32 (5%) q-wave myocardial infarctions, and 14 patients (2%) had transient low output syndrome. There was one episode of hypoperfusion corrected by lengthening the left ITA. Angiography for clinical indications in 27 patients 1 to 35 months postoperatively (mean, 9.5+/-8.3 months) demonstrated a distal anastomotic patency of 100% for ITA and 82% for radial artery grafts.

CONCLUSIONS

Complete arterial revascularization can be achieved with an ITA and radial artery T-graft with low operative risk and acceptable early patency. These results support the continued investigation of this grafting strategy.

Long-term follow-up after coronary artery bypass grafting reoperation

BACKGROUND

Coronary artery bypass grafting (CABG) reoperation is being performed with increasing frequency.

OBJECTIVE

To determine the clinical outcome and the long-term results of a second CABG.

SETTING

An 1100-bed urban university-affiliated hospital.

DESIGN

Retrieval of data on selected parameters from medical records before surgery and prospective follow-up afterwards.

PATIENTS AND METHODS

We studied the outcomes of 498 consecutive patients who underwent CABG reoperation in our institution from January 1978 to December 1989 and who were followed postoperatively. Their perioperative mortality, morbidity, and long-term follow-up results were re-evaluated. The end points of the study were December 1997, 15 years of follow-up, or the patient's death.

RESULTS

The perioperative mortality rate was 3%. The cumulative survival rates were 90.1%, 74%, and 63.4% at the 5-year, 10-year, and 15-year follow-ups, respectively. The cardiac event-free survival rates were 91.5%, 83.4%, and 67.8% at the 5-year, 10-year, and 15-year follow-ups, respectively. The risk factors adversely affecting long-term survival were advanced age, hypertension, and a low left ventricular ejection fraction (LVEF).

CONCLUSIONS

The long-term results of cumulative survival and cardiac event-free survival in patients who underwent CABG reoperation are good. Although this reoperation is safe overall, advanced age, hypertension, and a decreased LVEF significantly increase the surgical risk.

[Ambulatory cardiac phase II rehabilitation--"the Cologne model"--including 3-year-outcome after termination of rehabilitation]

From January 1992 until December 1994 the Cologne model of ambulant cardiac rehabilitation (ACR) in the greater area of Cologne, Germany, was performed and is still in progress. In Germany until 1992 the cardiac rehabilitation was exclusively performed stationary. The objective of the "Cologne model" was to evaluate, whether the transfer of the stationary cardiac rehabilitation programs into the ambulatory setting is achievable without deficits in efficiency, safety and overall quality. The results obtained are intended to serve for standardization and quality control of future ambulatory cardiac rehabilitation programs in Germany. From 1992 to 1994 108 patients (94 men, 14 women; 52.3 +/- 8.0 years old) with coronary artery disease (CAD) which were compatible with the criteria of the "Cologne model" (Table 1) participated in the 4-week ACR. The indications for inclusion into the ACR were in 74 cases a myocardial infarction (MI), in 34 cases CAD without MI, but with PTCA/stent-procedure (Table 3). Seven patients discontinued the ACR prematurely, 2 patients because of cardiovascular reasons. Reasons for the preference of the ambulatory over a stationary cardiac rehabilitation program were in 40.6% of the patients refusal of "hospital ambience", in 43.6% familiar or in 12.9% professional reasons. During the 4-week ACR patients participated in a mean of 72.9 +/- 6.7 hours of therapy (Table 4). As a result of the ACR exercise tolerance increased highly significantly (**) from 116.4 +/- 28.8 to 129.9 +/- 34.6 watt). This improvement was maintained at the 1- and 3-year control (128.7 +/- 35.8**) examinations (Tables 5 and 7). One year after ACR 77% of the patients stated to be physically active in ambulatory heart groups (AHG) (27.6%) or on their own (49.4%). Three years after ACR the rate of regularly physically active patients still was 59.2%. Furthermore, as a result of ACR the dietary behavior was changed significantly. There was a reduction in the consumption of lipids by 20.8%, saturated fatty acids by 30.7% and of cholesterol by 30.5%. The plasma concentrations of cholesterol decreased from 231 +/- 49.8 to 213.2 +/- 35.9 mg%**. Six (and 12) months after ACR they increased again to 225.6 +/- 39.4 mg%. Three years after ACR the mean cholesterol level was 219.1 +/- 39.3 mg%. In the high risk group (cholesterol at the initial visit > 220 mg%) cholesterol levels were reduced from 266 +/- 44 to 232 +/- 31.9 mg%**. Six and 12 months after ACR they were 239.7 +/- 35.8 mg% and 245.8 +/- 32.6 mg%, respectively, (Tables 6 and 7) and still significantly lower than before ACR, though only 19% of the patients were treated with lipid lowering agents. Three years after ACR cholesterol were 234.6 +/- 37.7 mg%** in the high-risk group. 34.2% of the patients received lipid lowering agents. Mean body weight remained unaltered over the 3-year period. Smoking behavior was not altered significantly during the 4-week ACR. However, before the cardiovascular event 67.3% of the patients had smoked cigarettes. At the beginning and at the end of ACR 20.8% of the patients still smoked. During the ACR the number of smoked cigarettes was reduced significantly from 32.4 +/- 15.2 to 6.9 +/- 5.2 cigarettes per day. One year after ACR 23% of the patients were smokers, 3 years after ACR the percentage of smokers increased to 30.3%. Before ACR 73.3% of the patients were still working. During the first 6 months after ACR 68.2% returned to work and the percentage increased to 73% in the following 6 months. The results demonstrate that it is achievable to transfer the contents of the established stationary cardiac rehabilitation programs into the ambulatory setting without loss of efficiency, safety and overall quality. It is further confirmed, that it is necessary to continuously evaluate the results of the cardiac rehabilitation program on a long-term basis. (ABSTRACT TRUNCATED)

Cardiovascular surgery in the elderly

The elderly segment of the population is increasing rapidly, and surgeons are more frequently being requested to operate on this group of patients. A number of reports suggest that elderly patients have a significantly higher incidence of operative mortality and 30-day hospital mortality as compared with younger patients. Elderly patients also had a significantly higher increased incidence of complications, such as renal failure, prolonged ventilation, and incidence of strokes and postoperative cardiac arrest. Regarding coronary artery disease, elderly patients are more acutely sick on admission, are more likely to have triple-vessel disease, more likely have comorbid disease, and are usually less likely to receive an internal mammary artery graft. The presence of valvular disorders with concomitant coronary disease (especially mitral ischemic related valve disease) increases operative time, morbidity, and mortality. Efforts must continue to be made to gather data on outcomes of cardiac surgery in the elderly. Consideration must be given to modify the operative approach that minimizes cardiopulmonary bypass time, mitigates the multisystem organ injury associated with cardiopulmonary bypass, and decreases the likelihood of embolization from the ascending aorta. Future efforts must be made to develop measures to decrease the complications rate identified in elderly patients.

Clinical results of endarterectomy of the right and left anterior descending coronary arteries

In this study, we examined the clinical outcome of coronary endarterectomy. From 1990 to 1998, 4839 patients underwent surgical revascularization. Coronary artery bypass graft surgery (CABG) was performed alone on 4516 patients, was combined with right coronary artery endarterectomy (RCA-E) in 242 patients, and was combined with left anterior descending coronary artery endarterectomy (LAD-E) in 81 patients. An analysis of preoperative variables revealed a higher proportion of males (90.7% vs 80.2%, p < 0.001), of patients with low ejection fraction (< 35%; 4.6% vs 1.7%, p < 0.001), and of three-vessel disease (47.9% vs 36%, p < 0.001) in the RCA-E versus the CABG patients. There was a higher proportion of unstable angina (51.9% vs 40.3%, p = 0.04) in the LAD-E patients. The 30-day mortality rate for CABG was 2% versus 2.5% for RCA-E and 3.7% for LAD-E (p = NS). Perioperative myocardial infarction (MI) rate for CABG was 3.4% versus 7.0% for RCA-E (p < 0.001) and 4.9% for LAD-E patients (p = NS). Postoperative low cardiac output syndrome was recorded in 11.5% of CABG, 18.6% of RCA-E (p = 0.01), and 11.1% of LAD-E (p = NS) patients. Predictors of postoperative bad outcome (death, MI, low cardiac output, cerebrovascular accident) were preoperative intra-aortic balloon pump, repeat operation, ejection fraction of < 35%, renal insufficiency, female gender, RCA-E, and age over 70. Protective factors included the use of internal mammary artery, multiple arterial grafts, and warm cardioplegia. Actuarial analysis at 6, 12, and 24 months showed late mortality rates of 0.8%, 1.3%, and 2.1% for CABG; 1.2%, 3.7%, and 3.7% for RCA-E; and 2.9%, 2.9%, and 2.9% for LAD-E, respectively. Late MI occurrence was 0.4%, 0.4%, and 0.7% for CABG; 1.5%, 1.5%, and 2.7% for RCA-E; and 0% for LAD-E, respectively. Multivariate analysis found renal insufficiency, ejection fraction of < 35%, repeat operation, female gender, New York Heart Association functional class IV, and diabetes to be predictors for late adverse events (recurrence of angina, MI, and cardiac death), and RCA-E was found to be a predictor of late MI. We conclude that the use of coronary endarterectomy to achieve complete revascularization in patients with diffuse distal coronary artery disease is a reasonable option, associated with a minimal addition in complication rates.

Coronary artery surgery: the end of the beginning

In each of the first three decades of myocardial revascularization, conventional treatment has been revised completely. This lecture comments on three areas of discovery that have shaped the evolution of myocardial revascularization: science, technology development, and revascularization. The discoveries in all three areas are inexorably interrelated. The single greatest lesson learned so far is that conduit performance carries more prognostic weight than any other factor. We have observed that vein graft atherosclerosis is predictable, and that the first-generation lipid lowering drugs have a favorable effect in patients who achieve marked LDL reduction. Biologically better revascularization begins with use of the internal thoracic artery for grafting to the anterior descending coronary artery. As the results of internal thoracic artery grafting are widely reported, arterial bypass revascularization has expanded, notably by radial and gastroepiploic arteries. The results of bilateral internal thoracic artery grafting are discussed, including large-scale registry results of internal thoracic artery usage in the United States. The internal thoracic artery is significantly underutilized. Diabetes affects both endoluminal and surgical revascularization. The new pharmacology in cardiology interventions shows promise in diminishing restenosis and thrombosis even in diabetic patients. Conversely, extended internal thoracic artery grafting may also benefit diabetic patients. Now we are entering a new age of minimally invasive coronary surgery. We have passed through the early stages of mini-thoracotomy, and we are moving on to access through 1-cm ports, intrathoracic cannulation, antegrade and retrograde myocardial protection, and computer guided three-dimensional vision and instrumentation. The potential for robotic control adds greater precision, ease of use, and safety. This new technology will be integrated with diagnostic information, intraoperative monitoring, anesthesia and perfusion data, cost accounting, and surgical note transcription. The operating room of the future will package intraoperative information and is adaptable to all surgical specialties. The future of coronary artery surgery will depend on minimally invasive techniques, all-arterial grafting, and selective lipid modification to reduce progressive atherosclerosis. The conclusion of this decade marks the end of the beginning. The new generation of cardiothoracic surgeons will share in an array of technology and research unmatched in previous decades.

Reoperation for recurrent coronary artery disease: results of 200 consecutive cases

BACKGROUND

It is well known that reoperation for recurrent coronary artery disease is more difficult than primary coronary artery bypass grafting. However, it is possible to reduce the morbidity and mortality of reoperation to the same level as the initial procedure with careful surgical technique.

METHODS

A retrospective study of the first 200 patients who underwent redo coronary bypass grafting was undertaken.

RESULTS

In the first 200 cases of redo coronary bypass grafting at St George Hospital, Sydney (August 1986-January 1995), there were five in-hospital deaths (2.5%). There was one case of sternal infection (0.5%), which required surgical debridement, three cases of stroke (1.5%), one case of postoperative bleeding (0.5%), which required a return to theatre and six cases (3%) required mechanical ventilation for more than 24 h. The need for major postoperative support (such as intra-aortic balloon pumping/adrenaline infusion) was significantly affected by the degree of urgency and the degree of pre-operative ventricular impairment.

CONCLUSIONS

The mortality rate of redo coronary artery bypass grafting in this series is similar to that of primary surgery described in other reports.

Should angiographically disease-free saphenous vein grafts be replaced at the time of redo coronary artery bypass grafting?

BACKGROUND

Controversy exists regarding the management of angiographically disease-free saphenous vein grafts at the time of redo coronary artery bypass grafting (CABG). Some authorities favor replacement of these disease-free grafts, arguing that occlusion is likely in the near future. Others believe that these grafts are "biologically privileged" and should not be replaced.

METHODS

One hundred thirty-two consecutive patients (113 men, 19 women, aged 46 to 88 years, mean 67 years) underwent redo revascularization with one or more angiographically disease-free saphenous vein grafts at the time of redo CABG. Thirty-six patients had the disease-free grafts replaced (R) and 96 did not (NR). The mean interval from the first CABG was 9.25 years.

RESULTS

Surgical mortality was comparable in the NR and R groups (5 of 96 or 5.2% versus 3 of 36 or 8.3%, respectively; p < 0.5). Survival at 1 and 3 years was higher in the NR group than the R group (98% versus 80%, and 95% vs. 66% respectively; p < 0.0001). Late myocardial infarction was less common in the NR group than in the R group (12 of 91 or 12.9% versus 12 of 33 or 36.4%; p < 0.003). Recurrent angina was less common in the NR than in the R group (21 of 91 or 23.1% versus 15 of 33 or 45.5%; p < 0.015). Cardiac hospitalization was required less commonly in the NR than in the R group (11 of 91 or 12.1% versus 12 of 33 or 36.4%; p < 0.002). In nondiseased grafts undergoing angiographic evaluation late after redo CABG, rate of new stenosis was lower in NR grafts than in R grafts (2 of 12 or 16.7% versus 2 of 3 or 66.7%; p < 0.05).

CONCLUSIONS

With a conservative approach that does not replace nondiseased saphenous vein grafts at redo CABG (1) there is no increase in operative mortality, (2) good late survival is obtained, (3) clinical ischemia related to the NR saphenous vein grafts is uncommon, and (4) NR grafts continue to be patent. We conclude that disease-free vein grafts may not require routine replacement at redo CABG. A randomized study is required for definitive resolution.

Single versus bilateral internal mammary artery grafts: 10-year outcome analysis

BACKGROUND

The superior long-term patency of the internal mammary artery (IMA) confers important short-term and late survival advantages when grafted to the left anterior descending coronary artery. However, it remains uncertain whether patients derive additional survival benefit when both IMAs are used in coronary revascularization.

METHODS

Between June 1983 and May 1986, 160 patients (mean age 60 years) received bilateral IMA grafts for coronary artery bypass procedures, and in 93% of patients, the right IMA was used to bypass the left coronary system. During a similar interval, a group of 161 patients matched for symptomatic status and extent of disease (mean age, 62 years) received a single left IMA and saphenous vein grafts.

RESULTS

The two groups were similar with respect to gender, preoperative angina class, priority status, extent of coronary artery disease, left ventricular function, and number of distal anastomoses. Diabetes was more prevalent in the patient group receiving a single IMA graft (27% versus 17.5%; p = 0.05). Early outcome was similar in the two groups; operative mortality was 0.6% for the patient group receiving single IMA grafts and 0% for those with bilateral IMA grafts. The mean follow-up of 320 hospital survivors was 10 years. Univariate analysis revealed significantly fewer overall deaths in the patients receiving bilateral IMA grafts (n = 30; p = 0.05), and less late cardiac mortality (n = 12; p = 0.016). Ten-year actuarial survival for patients dismissed from the hospital was 76% for those receiving single IMA graft versus 85% for those receiving bilateral IMA grafts. Multivariate analysis revealed diabetes (risk ratio = 1.73), advancing age (risk ratio = 1.08), and lower ejection fraction (risk ratio = 1.01) to be the only significant predictors of late cardiac death. Use of a single IMA graft was not significant (p = 0.138) despite a risk ratio of 1.78. Use of only a single IMA graft correlated with an increased risk of angina recurrence (p < 0.001), late myocardial infarction (p = 0.019), and risk of any cardiac event (p < 0.001).

CONCLUSIONS

Independent risk factors for late death were diabetes mellitus, older age, and reduced ejection fraction. Patients receiving bilateral IMA grafts had better long-term survival than those with a single IMA graft, but this was not independent of diabetes. Multivariate analysis, however, did confirm that compared with single arterial grafts, bilateral IMA grafting was an independent predictor of lower rates of angina recurrence, late myocardial infarction, and the composite end point of any cardiac event.

Reoperative coronary artery bypass without cardiopulmonary bypass

BACKGROUND

Conventional reoperative coronary artery bypass grafting using cardiopulmonary bypass carries relatively high mortality and morbidity.

METHODS

Seventy-seven patients underwent coronary artery bypass grafting without cardiopulmonary bypass in two centers between 1988 and 1994. Mean age was 65 +/- 8 years (mean +/- SD). Twenty-three (30%) were operated on urgently and 7 (9%) emergently. Nine (12%) were referred for operation up to 2 weeks after acute myocardial infarction. Fifteen patients (19%) had an ejection fraction less than or equal to 0.35. The mean number of grafts per patient was 1.7 (range, 1 to 3), and the internal mammary artery was used in 66 patients (86%). Only 18 patients (23%) received at least one graft to the circumflex artery. Hospital stay was 7.4 +/- 6.5 days.

RESULTS

Early events included operative death in 4 patients (5.2%), nonfatal myocardial infarction in 3 (3.9%), sternal infection in 2 (2.6%), and stroke in 0 (0%). Follow-up (30 +/- 15 months) showed 11 deaths (5 cardiac, 6 noncardiac), 2 (2.8%) nonfatal myocardial infarctions, and return of angina in 9 patients (12.8%). One- and 4-year actuarial survival rates were 90% and 69%, respectively.

CONCLUSIONS

Reoperative coronary artery bypass grafting without cardiopulmonary bypass has acceptable early and midterm outcome, and should be considered a viable alternative for properly selected patients.

Usefulness of hypertriglyceridemia in predicting myocardial infarction late after coronary artery bypass operation

We prospectively followed 446 consecutive patients who had coronary bypass operations 15 years earlier. Serum levels of cholesterol and triglycerides were measured before and 5 years after bypass, and we established the relation between these lipid levels and the incidence of myocardial infarction (MI) and cardiac mortality during 15 years of follow-up. Follow-up was complete in 99.8% of the patients and averaged 15.4 years for the survivors. Multivariate Cox proportional-hazards analysis revealed that patients with preoperative hypertriglyceridemia (> or = 2.0 mmol/L [176 mg/dl]) had a 2.1 times increased risk for MI during follow-up (p = 0.04). Hypertriglyceridemic patients 5 years after surgery had a 2.2 times increased risk for MI during the subsequent follow-up period, although this difference was not statistically significant (p = 0.09). The only significant risk factor for MI 5 years after surgery was smoking. Hypercholesterolemia (> or = 6.5 mmol/L [254 mg/dl]) both before and 5 years after surgery was not a risk factor for MI during follow-up. Cardiac mortality was not significantly related to either hypercholesterolemia or hypertriglyceridemia. Independent predictors for cardiac mortality were poor left ventricular function, diabetes mellitus, incomplete revascularization, and the use of sequential bypass grafts. These data provide evidence that hypertriglyceridemia, both before and 5 years after surgery, have predictive value for the incidence of MI during long-term follow-up after venous coronary bypass surgery.

Outcome of reoperative coronary bypass surgery versus coronary angioplasty after previous bypass surgery

BACKGROUND

The immediate and long-term outcomes of reoperative coronary artery bypass surgery (CABG) (n = 1561) and catheter-based coronary intervention (angioplasty) (n = 2613) were compared in patients from Emory University Hospitals who had previous CABG.

METHODS AND RESULTS

The surgical and angioplasty procedures and statistical methods were standard. Data were collected prospectively and entered into a computerized database. Followup was by letter, telephone, or additional events resulting in readmission. In the angioplasty group, 2.9% required in-hospital CABG. Hospital mortality was 1.2% after angioplasty versus 6.8% after repeat CABG (P < .0001). Recurrent angina was noted frequently at about 4 years and was more common after angioplasty. One-, 5-, and 10-year mortalities were 11%, 24%, and 49% after CABG versus 6%, 22%, and 38% after angioplasty. Survival corrected for baseline differences did not vary with the choice of procedure. There were more additional procedures after angioplasty. Patients undergoing angioplasty may be divided into those with procedures only in native coronary arteries (n = 1545), only in vein grafts (n = 869), and a mixture (n = 199), with respective 10 year survivals of 66%, 56%, and 65% (P < .0001).

CONCLUSIONS

These patients have a high incidence of events both in-hospital and in the long term. Although initial mortality was higher after CABG, after baseline differences were accounted for, there was no difference in the long term. Patients more frequently have additional procedures after angioplasty. Choice of therapy should consider clinical and angiographic suitability and patient preference.

Third-time coronary artery bypass operations: surgical strategy and results

BACKGROUND

Increasingly, patients are returning for a second, third, and even fourth coronary artery bypass graft (CABG) procedure.

METHODS

This report reviews the in-hospital and long-term outcomes for 102 patients undergoing a third or fourth CABG at Emory University from December 1977 to April 1994.

RESULTS

The mean interval from the first to second CABG was 5.2 +/- 3.5 years and from the second to the third CABG 6.8 +/- 4.1 years. The mean age was 6 +/- 9 years, 91% were male, 33% had hypertension, 16% diabetes, 86% class III or IV angina (Canadian Cardiovascular Society), 4.4% congestive failure (New York Heart Association), and 73% three-vessel disease. The in hospital mortality rate was 9.8%, with a perioperative myocardial infarction rate of 8.8% and a stroke rate of 1.9%.

CONCLUSIONS

These perioperative mortality and myocardial infarction rates are several times higher than those reported for initial revascularizations or first-time redo CABG operations. However, the 5- and 10-year survival rates of 79% and 59%, respectively, and a myocardial infarction-free survival of 62% at 5 years, the benefits of a third-time CABG procedure are apparent for this high-risk group of patients.