Analysis of Short- and Long-term Outcomes of Patients With Surgically Treated Left-sided Infective Endocarditis: A 5-Year Longitudinal Follow-up Study

This study aims to analyze survival, repeat hospitalization, and risk factors for surgically treated left-sided endocarditis. Retrospective review of all 166 (114 native and 52 prosthetic) patients operated between January 2004 and March 2015 was performed. Long-term survival and repeat hospitalization data for 134 of 166 patients were obtained via linked clinical databases with the Manitoba Centre for Health Policy. Kaplan-Meier estimates of survival and hospital readmission and Cox multivariable regression analysis of factors influencing outcomes were performed. Survival at 1 and 5 years was 91% and 80%, respectively, and major adverse prosthesis-related event repeat hospitalization rates were 12% and 21%, respectively. Repeat hospitalization because of endocarditis was 7% and 11% at 1 and 5 years, respectively. Survival and repeat hospitalization were similar for aortic and mitral valves. Survival after surgically treated endocarditis was similar to survival for age-, sex-, and valve-matched surgical valve replacements for noninfectious indications (P = 0.53). Viridans Streptococci was the most common organism in native valve endocarditis, and culture negative endocarditis was most common in prosthetic valves. Prosthetic valve endocarditis (P < 0.01) and preoperative renal dysfunction (P < 0.01) were risk factors for in-hospital mortality and major postoperative adverse events. Diabetes and renal dysfunction were associated with poor long-term survival, functional survival, and repeat hospitalization. This analysis suggests that surgery remains a very effective tool in management of these complex patients in terms of survival and major adverse prosthesis-related event repeat hospitalization.

Outcomes of octogenarians discharged from the hospital after prolonged intensive care unit length of stay after cardiac surgery

OBJECTIVE

Octogenarians offered complex cardiac surgery frequently experience a prolonged intensive care unit length of stay; however, minimal data exist on the outcomes of these patients. We sought to determine the rates and predictors of 1-year noninstitutionalized survival ("functional survival") and rehospitalization for octogenarian patients with prolonged intensive care unit length of stay after cardiac surgery and who were discharged from hospital.

METHODS

The outcomes of discharged patients aged 80 years or more who underwent cardiac surgery with prolonged intensive care unit length of stay (≥5 consecutive days) from January 1, 2000, to December 31, 2011, were examined retrospectively from linked clinical and administrative provincial databases. Regression analysis was used to determine predictors of 1-year functional survival and rehospitalization after discharge from the hospital.

RESULTS

A total of 80 of 683 (11.7%) discharged octogenarian patients had prolonged intensive care unit length of stay. Functional survival at 1 year was 92% and 81% for those with nonprolonged and prolonged intensive care unit lengths of stay, respectively (P < .01). Lack of outpatient physician visits within 30 days of discharge (hazard ratio, 5.18; P < .01) was a significant predictor of poor 1-year functional survival. The 1-year rehospitalization rates were 38% and 48% for those with nonprolonged and prolonged intensive care unit lengths of stay, respectively, with 41% of all rehospitalizations occurring within 30 days of initial discharge. A rural residence (hazard ratio, 1.82; P < .01) and nosocomial pneumonia during patients' operative admissions (hazard ratio, 2.74; P < .01) were associated with rehospitalization within 30 days of discharge.

CONCLUSIONS

Octogenarians with prolonged intensive care unit length of stay have acceptable functional survival at 1 year but have high rates of early rehospitalization. Access to health services may influence functional survival and early rehospitalizations. These data suggest that close follow-up of these vulnerable patients after hospital discharge is warranted.

Early Rehospitalization After Prolonged Intensive Care Unit Stay Post Cardiac Surgery: Outcomes and Modifiable Risk Factors

Background

Prolonged intensive care unit length of stay (prICULOS) following cardiac surgery (CS) in older adults is increasingly common but rehospitalization characteristics and outcomes are understudied. We sought to describe the rehospitalization characteristics and subsequent non‐institutionalized survival of prICULOS (ICULOS ≥5 days) patients and identify modifiable risk factors to decrease 30‐day rehospitalization.

Methods and Results

Consecutive patients from January 1, 2000 to December 31, 2011 were analyzed utilizing linked clinical and administrative databases. Logistic regression was used to identify risk factors associated with 30‐day rehospitalization. Out of 9210 consecutive patients discharged from the hospital alive, 596 (6.5%) experienced prICULOS. Cumulative incidence of rehospitalization for the prICULOS cohort at 30 and 365 days was 17.5% and 45.6% versus 11.4% and 28.1% for non‐prICULOS (P<0.01). Over 40% of rehospitalizations for the entire cohort occurred within 30 days of discharge costing over $12 million. The most common reasons for rehospitalization were heart failure (in prICULOS) and infection (in non‐prICULOS). Rehospitalization within 30 days was associated with a 2.29‐fold risk of poor 1‐year noninstitutionalized survival for the entire cohort. Potentially modifiable factors affecting 30‐day rehospitalization included lack of physician visits within 30 days of discharge (odds ratio 2.11; P=0.01), and preoperative anxiety diagnosis (odds ratio 2.20; P=0.01).

Conclusions

PrICULOS patients have high rates of rehospitalization that is associated with an increased rate of poor noninstitutionalized survival. Addressing modifiable risk factors including early postdischarge access to physician services, as well as access to mental health services may improve patient outcomes.

Use of Cardiopulmonary Bypass in High-Risk Patients Is a Predictor of Adverse Outcome

High-risk patients experience substantially more compli cations after coronary artery bypass grafting (CABG). We hypothesized that these patients are uniquely vulner able to cardiopulmonary bypass and compared postop erative outcomes between high-risk patients undergo ing off-pump CAB (OPCAB) and conventional CABG. Prospective provincial cardiac care registry and retro spective chart data were reviewed for 1,850 consecutive patients at our institution between January 1996 and January 1999. From this, 235 patients, 36 OPCAB and 199 CABG, were identified as high risk (modified Parson net score ≥15). Risk factor analysis showed the popula tions were equivalent in perioperative risk with mean modified Parsonnet scores of 18.1 ± 3.4 (OPCAB) and 18.7 ± 4.2 (CABG) (P = .4). In total, 6% of OPCAB and 40% of CABG patients suffered major complications leading to extended hospital/intensive care unit (ICU) stay or death ( P ≤ .001). Mean hospital stays were 7.0 ± 4.0 days (OPCAB) and 10.6 ± 10.2 days (CABG) ( P ≤ .001). Mean ICU stays were 23.9 ± 9.7 hours (OPCAB) and 64.9 ± 128.3 hours (CABG) ( P ≤ .001). Mortality was 0% in the OPCAB group and 6% in the CABG group (P = .2). Multivariate predictors of experiencing a major complication were: use of cardiopulmonary bypass (OR 5.1, 95 Cl 2.1-12.1), age > 80 (OR 2.5, 95 Cl 1.7-7.5), female (OR 3.0, 95 Cl 1.6-5.4), repeat operation (OR 2.5, 95 Cl 1.2-5.4), and ejection fraction <40% (OR 2.4, 95 Cl 1.2-4.7). Extracorporeal circulation is the most impor tant predictor of postoperative complications after CABG in high-risk patients. Off-pump surgery substantially reduces morbidity in this group, and further study of the protective effects of this emerging modality are war ranted.

Clinical outcomes of minimally invasive endoscopic and conventional sternotomy approaches for atrial septal defect repair

BACKGROUND

Concerns remain that minimally invasive atrial septal defect (ASD) repair may compromise patient outcomes. We compared clinical outcomes of adult patients undergoing ASD repair via a minimally invasive endoscopic approach versus a "gold standard" sternotomy.

METHODS

We retrospectively reviewed the clinical outcomes of consecutive patients who underwent ASD patch repair at our institution between 2002 and 2012. We compared in-hospital/30-day mortality, postoperative complications, length of stay in hospital and in the intensive care unit and blood product requirements between patients who underwent right mini-thoracotomy (MT) and those who underwent conventional sternotomy.

RESULTS

During the study period, 73 consecutive patients underwent ASD patch repair at our institution: 51 (age 47 ± 16 yr, 66.7% women) in the MT group and 22 (age 46 ± 21 yr, 59.1% women) in the sternotomy group. In-hospital mortality was similar between the 2 groups (MT 0% v. sternotomy 4.5%, p = 0.30). There were no significant differences in any postoperative complications or blood product requirements. No patients in the MT group suffered stroke, retrograde aortic dissection or leg ischemia. Mean intensive care unit (MT 1.2 ± 1.2 d v. sternotomy 1.7 ± 2.2 d, p = 0.26) and hospital length of stays (MT 5.1 ± 2.2 d v. sternotomy 6.3 ± 3.6 d, p = 0.17) were similar between the groups; however, there was a trend toward fewer patients requiring prolonged hospital stays (> 10 d) in the MT group (3.9% v. 18.2%, p = 0.06).

CONCLUSION

Repair of ostium secundum and sinus venosus ASD can be performed safely via MT endoscopic approach with similar outcomes as sternotomy. Patient preference for a more cosmetically appealing incision may be considered without concern of compromised outcomes.

Cost-effectiveness analysis of rheumatic heart disease prevention strategies

Rheumatic heart disease (RHD), secondary to group A streptococcal infection is endemic in the developing as well as parts of the developed world with significant costs to the patient, and to the healthcare system. We briefly review the prevalence and cost of RHD in developed and developing nations. We subsequently develop a Markov model to evaluate the cost-effectiveness of three strategies (vs standard no prevention) for preventing RHD in a developing world country: primary prophylaxis (throat swab to detect and subsequently treat group A streptococci as needed); primary prophylaxis (antibiotic prophylaxis for all) with benzathine penicillin G once monthly to all patients (ages 5-21 years) regardless of evidence of infection; and secondary prophylaxis with monthly only to those with echocardiographic evidence of early RHD. Our model suggests that echocardiographic screening and secondary prophylaxis is the best strategy although the strategies change depending on parameters used.

Bioprosthetic heart valves of the future

Glutaraldehyde-fixed bioprosthetic heart valves (GBHVs), derived from pigs or cows, undergo structural valve deterioration (SVD) over time, with calcification and eventual failure. It is generally accepted that SVD is due to chemical processes between glutaraldehyde and free calcium ions in the blood. Valve companies have made significant progress in decreasing SVD from calcification through various valve chemical treatments. However, there are still groups of patients (e.g., children and young adults) that have accelerated SVD of GBHV. Unfortunately, these patients are not ideal patients for valve replacement with mechanical heart valve prostheses as they are at high long-term risk from complications of the mandatory anticoagulation that is required. Thus, there is no "ideal" heart valve replacement for children and young adults. GBHVs represent a form of xenotransplantation, and there is increasing evidence that SVD seen in these valves is at least in part associated with xenograft rejection. We review the evidence that suggests that xenograft rejection of GBHVs is occurring, and that calcification of the valve may be related to this rejection. Furthermore, we review recent research into the transplantation of live porcine organs in non-human primates that may be applicable to GBHVs and consider the potential use of genetically modified pigs as sources of bioprosthetic heart valves.

Longer in-hospital wait times do not result in worse outcomes for patients requiring urgent coronary artery bypass graft surgery

BACKGROUND

In certain health care systems, patients wait for non-emergency services. Although waiting may not be considered acceptable, the delay may allow for patient optimization, such as giving time for "toxic" agents to be cleared, that could improve outcomes. We sought to determine the relationship between wait times and outcomes in in-hospital patients undergoing urgent coronary artery bypass graft (CABG) surgery.

METHODS AND RESULTS

A prospectively collected database of consecutive, medically urgent, but clinically stable patients undergoing CABG surgery from 1995 to 2007, was analyzed. A total of 3067 patients with need for urgent CABG surgery with various in-hospital wait times (n = 440, 0-2 days; n = 799, 3-5 days; n = 1317, 6-10 days; n = 511, 11-15 days) were included. There were no differences in mortality, intensive care unit (ICU) or post-surgery hospital length of stay (LOS) among the patient groups. Multivariate logistic regression analysis revealed that wait time was not associated with mortality (P = 0.625). Due to changes in the nonsurgical management of coronary artery disease, a separate analysis of patients, from 2002 to 2007, was also performed to explore contemporary results. In the latter subset, 1495 patients (n = 175, 341, 720, 259, in the same 4 respective wait-time groups) were included; the 0-2 days patient group underwent more blood transfusions (50% vs 38%; P = 0.01), prolonged ventilation (6% vs 2%; P = 0.05), post-operative dialysis (2% vs 0%; P = 0.08), and longer ICU LOS (26 vs 23 hours; P = 0.02) compared with the 3-5 days patient group. The Society of Thoracic Surgeons mortality risk scores of the 0-2 days and 3-5 days groups were the same (1.5%). Multivariate regression analysis revealed that increased wait time was associated with fewer patients requiring blood transfusion (P < 0.05) for CABG surgery.

CONCLUSION

Waiting for in-hospital urgent CABG surgery does not lead to worse patient outcomes and may, in fact, reduce the procedural and medical risks of postoperative blood transfusions, prolonged ventilation, dialysis, and shorten ICU LOS.

Can long-term ventricular assist devices be safely implanted in low-volume, non-heart transplant centres?

BACKGROUND

Mechanical circulatory support (MCS) using long-term ventricular assist devices (VADs) is an established therapy in select patients with advanced heart failure. Studies have suggested that outcomes after VAD implantation may be dependent on institutional procedural volume, and outcome data from non-transplant centres are lacking. This study reviews the outcomes of patients who received a long-term VAD at our centre to determine if these devices can be safely implanted at tertiary care, low-volume, non-transplant centres.

METHODS

We conducted a single-centre retrospective cohort study, examining the clinical outcomes of consecutive patients who received a long-term VAD over a 42-month period.

RESULTS

During the study period 73 patients required MCS, of whom 16 received a long-term VAD. This select group had a mean Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile of 1.6 (0.9) and before implantation 94% required at least 1 inotropic medication, 69% had suffered a cardiac arrest, 63% required an intra-aortic balloon pump, 69% required mechanical ventilation, and 44% required short-term MCS. The primary outcome of survival to transplant or ongoing MCS at 1 year was achieved in 75% of patients. Operating room, intensive care unit, and hospital survival were 100%, 88%, and 81%, respectively.

CONCLUSIONS

Long-term VADs can be implanted at low-volume, nontransplant centres with survival rates comparable with contemporary clinical trials. Availability of a specialty trained multidisciplinary team with expertise in short-term and long-term MCS options facilitates appropriate patient selection and might be more important than institutional volume in determining outcomes after implantation.

The acutely occluded left main coronary artery culprit in cardiogenic shock and initial percutaneous coronary intervention: a substudy of the Manitoba “no option” left main PCI registry

We aim to describe the in-hospital outcomes of the first reported Canadian cohort of patients with cardiogenic shock and acute myocardial infarction (MI) due to acute and total occlusion of the left main coronary artery, treated with initial percutaneous coronary intervention (PCI). Acute left main thromboses with cardiogenic shock were identified (N = 8) from a retrospective consecutive cohort of high risk left main PCI (N = 56) performed at our institution from 2004–2009. The mean age was 62.3 ± 13.2 years, with 6 (75%) male patients. Successful PCI was performed in all patients, with thrombectomy utilized in 4 patients (50%), stenting in 7 patients (88%), and intra-aortic balloon pump augmentation in 7 patients (88%). Two patients (25%) required extracorporeal membrane oxygenation (ECMO) and 2 other patients required ventricular assist devices. Post-PCI coronary artery bypass grafting (CABG) was performed for 2 patients (25%). The mean SYNTAX score was 26.6 ± 10.5. The mean logistic EuroSCORE was 30.4 ± 12.6%. In-hospital mortality occurred in 3 patients (38%). Acute left main occlusion is a rare but devastating presentation of myocardial infarction, invariably with cardiogenic shock. Emergent PCI may be an effective method to acutely revascularize this subset of patients; however, aggressive post-PCI care including ECMO, CABG, and ventricular support may be required to improve patient survival.

Abstract 105: 24/7 In-House Consultant Staffing for Cardiac Surgical ICU Patients: A Cost-Effective Model

Introduction: Intensive care staffing models vary amongst institutions. There is increasing evidence that in-house consultant care is beneficial in the intensive care unit. We have previously published beneficial results associated with 24-hour / 7-days a week in-house consultants working in a dedicated post-cardiac surgical unit. The cost-effectiveness of employing 24-hour / 7-days a week in-house consultants (both in the postoperative cardiac surgery and the general systems intensive care unit settings) remains largely unknown. The objective of this study was to analyze the cost implications of such a model.

Methods: Using a prospectively collected database, an observational before and after cohort analysis of consecutive patients undergoing a cardiac surgical procedure at a single tertiary center was performed. The control cohort (n=1425) consisted of patients admitted to a traditional mixed surgical intensive care unit (SICU) from Jan.2005 - Jan.2007. The intervention cohort (n=1824) consisted of patients admitted to a newly created cardiac surgery ICU (CICU) from Jan.2007 - Sept.2008, which was staffed by 24/7 in-house consultants. Cost estimates were calculated for each patient from time of ICU admission to hospital discharge. For comparison purposes, propensity analysis was performed matching both cohorts on over twenty clinical, physiological, and surgical variables.

Results: 1,182 patients (83%) per cohort were matched. Pre-operative demographics and surgical variables were similar between both cohorts. The CICU model was associated with a significant decrease in mean hospital bed, laboratory, and blood transfusion costs (Table 1). A higher mean ICU consultant salary cost offset this. Total estimated median cost was ∼14% lower in the CICU model relative to the SICU model (Table 1).

Conclusions: We present a large before-after observational study examining the cost-effectiveness of 24/7 ICU consultant staffing. Our data suggests that the greater savings associated with improvement in post-operative care offsets the salary costs associated with 24/7 in-house consultants.

Influenza myocarditis and myositis: case presentation and review of the literature

Myocarditis, a general inflammatory condition of the heart muscle, can result from a variety of etiologies, the most common being viral. Despite common pathogens, concomitant myocarditis and myositis remains a rare event. Although a common cause of respiratory illness, extrapulmonary infections with influenza are infrequent. We describe the case of a patient who presented to our centre with concomitant "seasonal" H1N1 influenza A myocarditis further complicated by pan-myositis. The patient's condition rapidly declined, eventually requiring biventricular mechanical support, in addition to multilimb fasciotomies. The cardiac support required was progressive, from a percutaneous left ventricular assist device, to extracorporeal membrane oxygenation, to eventual biventricular assist device support for bridge-to-transplantation. This case motivated a detailed review of the literature (a total of 29 cases were identified), in which we found that patients with influenza myocarditis/myositis were predominantly female (63%) and young (mean age 33.2 years) and continue to have a high incidence of morbidity and mortality (27%). As a result of its atypical pattern, the 2009 H1N1 pandemic strain has gained attention. From our review, we found 7 patients with of 2009 H1N1 pandemic influenza myocarditis. Serial serum cytokine analysis did not demonstrate a "cytokine storm," which has been associated with other virulent influenza strains. The PB1-F2 marker in particular has been associated with a vigorous cytokine response. The 2009 H1N1 and "seasonal" influenza strains lack this marker. In those patients with community-acquired influenza, interleukin-6 has been shown to correlate with symptoms. For patients with myocarditis resulting in shock, mechanical circulatory support has gained acceptance as a means to recovery or transplantation.

Interprovincial spoke-to-hub transport using the Impella Recover LP 5.0 left ventricular assist device as a bridge to long-term circulatory support

Current hospital administrative practices categorize health care centres in a network of&nbsp; 'spokes' (primary care centres) and 'hubs' (tertiary care centres). For the treatment of cardiogenic shock, long-term left ventricular assist devices (LVADs) and transplant therapies are only used at a few hub centres nationwide and are, thus, only available to patients living in close proximity to these centres. The relatively lower technical requirements of the Impella Recover LP 5.0 LVAD (ABIOMED Inc, USA) translate into greater use by spoke centres for the short-term treatment of cardiogenic shock, and facilitate appropriate stabilization and subsequent transportation to a suitable hub centre. Based on a review of the literature, the present report describes the first case demonstrating successful use of the Impella Recover LP 5.0 LVAD, implanted under local anesthetic, for the purposes of interprovincial spoke-to-hub transport in a bridge-to-bridge-to-transplant procedure. By providing an economical and technically straightforward alternative to traditional extracorporeal membrane oxygenation, the present case demonstrates that less invasive LVADs are valuable to the spoke-and-hub model for delivery of specialized cardiac care.

Iatrogenic acute aortic dissection in a patient with Marfan syndrome: unusual site of intimal tear

Iatrogenic acute aortic dissection is a rare, but well-known, potentially lethal complication following cardiac surgery. Iatrogenic acute aortic dissection in Marfan syndrome patients with normal aortic parameters has not been well studied. The location of the intimal tear, along the lesser curvature of the arch, poses the question if more attention should be given to this subgroup of patients. Due to their underlying aortic pathology and the nature of cardiac surgery, patients with Marfan syndrome will continue to be at greater risk than the average population.

Computer-enhanced telemanipulation in mitral valve repair: preliminary experience in Canada with the da Vinci robotic system

BACKGROUND

Investigation into the surgical application of robot technology continues to expand. We report on the first case series of robotic-assisted mitral valve (RAMV) repair in Canada with use of the da Vinci telemanipulation system (Intuitive Surgical, Sunnyvale, Calif.).

METHODS

Between February 2004 and August 2004, 10 patients with normal left ventricular function and severe mitral valve regurgitation underwent RAMV repair with use of the da Vinci system. Peripheral cardiopulmonary bypass, transthoracic aortic cross-clamping and antegrade cardioplegia were used in all cases. A minithoracotomy in the fourth intercostal space and 2 ports in the third and fifth intercostal spaces allowed surgical access. All mitral valve valvuloplasties and band annuloplasties were done endoscopically with robotic assistance.

RESULTS

Nine of 10 patients had successful valve repair, and 1 had conversion to mitral valve replacement due to persistent regurgitation. There were no deaths, strokes or need for sternotomy. One patient required re-exploration for bleeding.

CONCLUSION

Minimally invasive RAMV repair is feasible and safe with promising early postoperative results when performed by experienced surgical personnel accomplished in both mitral valve procedures and robotic techniques.

The new cardiac surgery patient: defying previous expectations

BACKGROUND

Studies conducted before 1999 of patients who had coronary artery bypass graft surgery (CABG) have shown a tendency toward increasing preoperative risk factors. This study examines whether this trend of increasing risk in patients who have cardiac surgery has continued since 1999 and whether its effect on mortality and morbidity has changed.

METHODS

We prospectively collected data for 2754 patients who had cardiac surgery, divided them into 4 cohorts based on the year of operation (2000-2003) and analyzed the data according to 56 predefined preoperative, operative and postoperative variables.

RESULTS

There were no significant changes in most preoperative risk factors over time, except for significant decreases in the proportion of elective (p = 0.016) and emergency/salvage operations (p < 0.001) and increases in urgent procedures and in the number of patients with congestive heart failure (CHF) (p < 0.001). The proportion of CABG procedures decreased significantly, whereas the proportion of valve, CABG plus valve, and non-CABG surgeries increased. A significant increase in multiarterial graft use and a decrease in off-pump coronary artery bypass procedures were observed. Postoperative complication rates did not change during the 4 years except for a significant decrease in wound infections. No significant changes in overall mortality and mortality across types of procedure were observed. Median observed/expected ratios for expected length of stay in hospital and risk of mortality did not change significantly over time.

CONCLUSION

Patients' risk factors, except for CHF, did not change from 2000 to 2003. Despite more complicated procedures, the postoperative complication rates did not change except for a decrease in wound infections. These results suggest that the assumption of an inexorably increasing patient risk profile should be re-evaluated.

Is obesity a predictor of mortality, morbidity and readmission after cardiac surgery?

INTRODUCTION

Obesity has been described as a risk factor for the development of coronary artery disease, but it has not been determined whether obesity is associated with adverse outcomes after cardiac surgery. Therefore, we analyzed a large cohort of patients who had undergone cardiac surgery to determine whether obesity is a predictor of mortality, morbidity or early readmission to hospital.

METHODS

At the London Health Sciences Centre, an academic tertiary care centre, we prospectively entered data from the cardiac surgical database from July 1999 to April 2002. We collected data on 1310 consecutive, unselected patients who underwent cardiac surgery during that time. We assessed the degree of obesity using the body mass index (BMI), and we prospectively documented the occurrence of 10 major complications after surgery. They included stroke, reoperation for bleeding, life-threatening cardiac arrest or arrhythmia, new renal failure requiring dialysis, septicemia, mediastinitis, sternal dehiscence, respiratory failure, postoperative myocardial infarction and low cardiac output necessitating intra-aortic balloon pump use. Univariable and multivariable analyses were conducted to determine the factors associated with and predictive of postoperative death and major complications.

RESULTS

An increased BMI did not increase the risk of early postoperative death. Furthermore, increased BMI was not a predictor of a patient experiencing any of the major complications, except sternal dehiscence. An increased BMI was associated with a higher likelihood of readmission to hospital within 30 days of discharge.

CONCLUSION

Obesity was not associated with adverse outcomes after cardiac operations, aside from the increased risks of sternal dehiscence and early hospital readmission.

Extracorporeal femoral to carotid artery perfusion in selective brain cooling for a giant aneurysm

Giant partially thrombosed intracranial aneurysms are a challenge to treat surgically, and they are also unsuitable for coil embolization. The current options for treatment include extracranial-intracranial bypass followed by parent artery occlusion or direct surgical occlusion in which deep hypothermic circulatory arrest is used. The authors report the use of another approach in the treatment of a giant anterior circulation aneurysm: selective brain cooling accomplished by extracorporeal perfusion. This facilitated direct surgery on a 4.2-cm, partially thrombosed aneurysm of the middle cerebral artery (MCA). A brain temperature of 22 degrees C was achieved after 20 minutes of perfusion with blood cooled using an extracorporeal technique of femoral-common carotid artery perfusion. This was followed by a 20-minute period of surgical trapping of the MCA, then evacuation and clip occlusion of the aneurysm. During the period of selective brain cooling the patient's core body temperature was maintained above 35 degrees C. This technique of selective brain cooling may be a useful alternative to currently available surgical and endovascular methods of treatment for giant aneurysms.

Robotic Surgery, the First 100 Cases: Where Do We Go from Here?

Abstract Background: Since the robot-assisted cardiac surgery program at this center was initiated in September 1998 the results have been regularly critically evaluated. We report a retrospective review of the first 100 robotic procedures and their evolution. Methods: Between September 1998 and May 2001, 146 patients underwent robot-assisted procedures. All procedures were performed using the Aesop robotically controlled camera or the Zeus robotic system. A harmonic scalpel was used for all internal thoracic artery (ITA) dissections whether the dissections were performed manually or with the Zeus robotic system. Results: There were 123 closed-heart and 23 open-heart procedures, which included 8 atrial-septal defect repairs, 11 mitral valve repairs, 4 mitral valve replacements, 57 Aesop ITA takedowns, 68 Zeus ITA takedowns, and 13 totally endoscopic coronary artery bypass grafts. Graft patency in Aesop and Zeus ITA takedown groups was 96%. All the patients were New York Heart Association class I after their procedures. Conclusion: With the development of surgical robots, it has been possible to perform endoscopic cardiac surgery for selected cases. Future directions will be demonstrated, including telementoring, telesurgery, and Zeus-assisted initiatives in cardiac surgery and other surgical disciplines.

Hybrid approach for minimally-invasive operative therapy of arrhythmias

The failure of linear radiofrequency lesions to effectively replace operative therapy for atrial fibrillation (AF) is largely related to the inability to produce complete lines of conduction block. While pulmonary vein ablation enjoys success in patients with paroxysmal AF, patients with persistent AF and permanent AF fair less well. As such, a minimally-invasive, preferably "off pump" robotically-assisted procedure for complex arrhythmias like AF remains highly desirable. The shift to access from a mini-thoracotomy or port access will limit visualization and direct access to the ablation target. For the most part, the tools to overcome these limitations are not yet developed. As these develop, it is critical for the electrophysiologic effects of the delivered lesions to be assessed. With the development of non-fluoroscopic mapping systems and advances in imaging, a hybrid operative, electrophysiology (EP) suite can be equipped to provide full support for the surgeon and electrophysiologist. This will provide the opportunity to assess the efficacy and safety of ablation lesions, ideally with direct feedback to the surgeon. A hybrid approach will provide the opportunity to gain insights into the success and failure of specific ablation tools, approaches and lesions. This step will be crucial in understanding why specific procedures ultimately fail to cure AF and other complex arrhythmias.

Analysis of the learning curve in telerobotic, beating heart coronary artery bypass grafting: a 90 patient experience

BACKGROUND

Recent articles have commented on the "learning curve" in robotic-assisted coronary artery bypass grafting. We systematically studied this phenomenon using standard statistical and cumulative sum (CUSUM) failure methods.

METHODS

Ninety patients underwent internal thoracic artery (ITA) takedown and an attempt at ITA to coronary bypass on the beating heart using the Zeus telerobotic system from September 1999 to December 2001. The rates of mortality and 11 predefined major complications were compared in five quintiles of 18 consecutive patients each and a CUSUM curve was generated for the entire cohort.

RESULTS

All patients but one underwent successful endoscopic ITA takedown. Thirteen patients had a totally endoscopic anastomosis, whereas in 61 a small mini-thoracotomy or mini-sternotomy was used. Sixteen patients (17.8%) were converted electively to a sternotomy: 11 patients underwent off-pump and 5 patients on-pump surgery. There were no deaths; 13 patients (14.4%) incurred one or more of the 11 major complication(s), including 5, 1, 2, 3, and 2 in each of the five quintiles (p = 0.39). Standard statistical analyses identified a significant decrease in operating room time (p < 0.0001), as well as a decrease in the incidence of an occluded graft or wrong vessel grafted from quintiles 1 to 5 (p = 0.03). On CUSUM analysis, the failure curve was steep for the first 18 to 20 patients, before moderating its slope for the remainder of the experience.

CONCLUSIONS

Robotic ITA to coronary bypass on the beating heart has a moderately steep learning curve, which is mitigated by further experience. CUSUM analysis complimented standard statistical methods in detecting a cluster of suboptimal results during the early experience with this procedure.

Mitral valve aneurysm associated with aortic valve endocarditis and regurgitation

Mitral valve aneurysms are rare complications occurring most commonly in association with aortic valve infective endocarditis. [Decroly 1989, Chua 1990, Northridge 1991, Karalis 1992, Roguin 1996, Mollod 1997, Vilacosta 1997, Cai 1999, Vilacosta 1999, Teskey 1999, Chan 2000, Goh 2000, Marcos- Alberca 2000] While the mechanism of the development of this lesion is unclear, complications such as perforation can occur and lead to significant mitral regurgitation. [Decroly 1989, Karalis 1992, Teskey 1999, Vilacosta 1999]; The case of a 69-year-old male with Streptococcus Sanguis aortic valve endocarditis and associated anterior mitral leaflet aneurysm is presented. Following surgery, tissue pathology of the excised lesion revealed myxomatous degeneration and no active endocarditis or inflammatory cells. This may add support to the hypothesis that physical stress due to severe aortic insufficiency and structural weakening, without infection of the anterior mitral leaflet, can lead to the development of this lesion.

Effect of off-pump coronary artery bypass grafting on risk-adjusted and cumulative sum failure outcomes after coronary artery surgery

BACKGROUND AND AIM

We have shown that cumulative sum (CUSUM) failure analysis may be more sensitive than standard statistical methods in detecting a cluster of adverse patient outcomes after cardiac surgical procedures. We therefore applied CUSUM, as well as standard statistical techniques, to analyze a surgeon's experience with off-pump coronary artery bypass grafting (OPCAB) and on-pump procedures to determine whether the two techniques have similar or different outcomes.

METHODS

In 320 patients undergoing nonemergent, first time coronary artery bypass grafting, preoperative patient characteristics, rates of mortality and major complications, and ICU and hospital lengths of stay were compared between the on-pump and OPCAB cohorts using Fisher's exact tests and Wilcoxon two sample tests. Predicted mortality and length of stay were determined using previously validated models of the Cardiac Care Network of Ontario. Observed versus expected ratios of both variables were calculated for the two types of procedures. Furthermore, CUSUM curves were constructed for the on-pump and OPCAB cohorts. A multivariable analysis of the predictors of hospital length of stay was also performed to determine whether the type of coronary artery bypass procedure had an independent impact on this variable.

RESULTS

The predicted mortality risk and predicted hospital length of stay were almost identical in the 208 on-pump patients (2.2 +/- 3.9%; 8.2 +/- 2.5 days) and the 112 OPCAB patients (2.0 +/- 2.2%; 7.8 +/- 2.1 days). The incidence of hospital mortality and postoperative stroke were 2.9% and 2.4% in on-pump patients versus zero in OPCAB patients (p = 0.09 and 0.17, respectively). Mechanical ventilation for greater than 48 hours was significantly less common in OPCAB (1.8%) than in on-pump patients (7.7%, p = 0.04). The rate of 10 major complications was 14.9% in on-pump versus 8.0% in OPCAB patients (p = 0.08). OPCAB patients experienced a hospital length of stay that was a median of 1.0 day shorter than on-pump patients (p = 0.01). The observed versus expected ratio for length of stay was 0.78 in OPCAB patients versus 0.95 in on-pump patients. On CUSUM analysis, the failure curve in OPCAB patients was negative and was flatter than that of on-pump patients throughout the duration of the study. Furthermore, OPCAB was an independent predictor of a reduced hospital length of stay on multivariable analysis.

CONCLUSIONS

OPCAB was associated with better outcomes than on-pump coronary artery bypass despite a similar predicted risk. This robust finding was documented on sensitive CUSUM analysis, using standard statistical techniques and on a multivariable analysis of the independent predictors of hospital length of stay.

[Clinical experience in thoracoscopic left internal mammary artery harvesting with voice activated robotic assistance]

Between September 1998 to February 2000, 45 consecutive patients underwent robotic-assisted, video-enhanced coronary artery bypass grafting. All IMA's were harvested using the voice-activated robotic assistant (AESOP 3000, Computer Motion Inc, Santa Barbara, CA) and the Harmonic scalpel (Ethicon Endo-Surgery, Cincinnati, OH). Left IMA's were successfully harvested in all patients. Harvested IMA's were anastomosed to LAD's under direct vision through limited left anterior thoracotomy. The IMA harvest time was 57.8 +/- 23.2 min, intraoperative graft flow was 34.3 +/- 20.5 ml/min, postoperative hospital stay was 3.9 +/- 1.5 days. The early postoperative angiogram showed that all grafts were patent. There was no mortality, no significant morbidity. The robotic assisted, video enhanced CABG provides safe and complete LIMA dissection with minimal manipulation and assures sufficient LITA length for tension free anastomosis.

A multicenter, randomized, controlled trial of Celsior for flush and hypothermic storage of cardiac allografts

BACKGROUND

A multicenter, randomized, controlled, open-label trial was conducted to evaluate the safety and efficacy of Celsior when used for flush and hypothermic storage of donor hearts before transplantation.

METHODS

Heart transplant recipients were randomized to one of two treatment groups in which donor hearts were flushed and stored in either Celsior or conventional preservation solution(s) (control). Study subjects were followed for 30 days after transplantation.

RESULTS

A total of 131 heart transplant recipients were enrolled (Celsior, n = 64; control, n = 67). The treatment groups were evenly distributed in donor and recipient base line characteristics. Graft loss rate was lower in the Celsior group on day 7 (3% versus 9%) and on day 30 (6% versus 13%), but the difference was not statistically significant based on 95% confidence interval analysis. No significant difference was measured between the Celsior and control groups in 7-day patient survival (97% versus 94%) and the proportion of patients with one or more adverse events (Celsior, 88%; control 87%) or serious adverse events (Celsior, 38%; control, 46%). Significantly fewer patients in the Celsior group developed at least one cardiac-related serious adverse event (13% versus 25%).

CONCLUSIONS

Celsior was demonstrated to be as safe and effective as conventional solutions for flush and cold storage of cardiac allografts before transplantation.

RAVECAB: improving outcome in off-pump minimal access surgery with robotic assistance and video enhancement

OBJECTIVE

To determine the efficacy of using the harmonic scalpel and robotic assistance to facilitate thoracoscopic harvest of the internal thoracic artery (ITA).

DESIGN

A case series.

SETTING

London Health Sciences Centre, University of Western Ontario, London, Ont.

PATIENTS AND METHODS

Fifteen consecutive patients requiring harvest of the ITA for coronary artery bypass grafting.

INTERVENTION

Robot-assisted, video-enhanced coronary artery bypass (RAVECAB) through limited-access incisions, using the harmonic scalpel and a voice-activated robotic assistant.

MAIN OUTCOME MEASURES

Ease and duration of the harvesting technique, complications of the procedure, graft flow and patency, and duration of postoperative hospitalization.

RESULTS

RAVECAB facilitated thoracoscopic dissection of the ITA with the harmonic scalpel in all cases. There were no conversions to a standard approach and no reoperations for bleeding. The mean (and standard deviation) ITA harvest time was 64.1 (22.9) minutes (range from 40 to 118 minutes). Robotic voice command capture rate was greater than 95%. Mean (and SD) intraoperative graft flows were 33.1 (26.8) mL/min (range from 14 to 126 mL/min). There was 100% graft patency on postoperative angiography. There were no deaths, perioperaive myocardial infarction or arrhythmias. Mean (and SD) postoperative hospitalization was 3.3 (0.8) days.

CONCLUSIONS

RAVECAB is a demanding procedure that addresses many of the disadvantages of the "conventional" minimally invasive coronary artery bypass. It allows complete pedicle dissection with minimal ITA manipulation and assures sufficient conduit length and a tension-free coronary artery anastomosis. All anastomoses were performed under direct vision through a 5- to 8-cm inferior mammary incision.

A comparison of robot-assisted versus manually constructed endoscopic coronary anastomosis

BACKGROUND

New technology has enabled surgeons to attempt totally endoscopic coronary artery bypass grafting. Our purpose was to compare three different techniques of totally endoscopic anastomosis using a porcine animal model.

METHODS

Porcine hearts were excised and the right coronary artery was dissected free for use as an arterial graft. The hearts were placed in a human thoracic model and an endoscopic arterial anastomosis between the free right coronary artery and the left anterior descending coronary artery was performed using one of the following: (1) two-dimensional visualization with straight endoscopic instruments (n = 8); (2) three-dimensional head-mounted visualization with curved endoscopic instruments (n = 7); or (3) three-dimensional visualization with robotic telemanipulation (n = 8). Pathologic analysis of suture placement, vessel trauma, and patency was performed. Anastomoses were graded according to quality, ease, and patency using a seven-point Likert scale (1 = excellent, 7 = very poor).

RESULTS

Endoscopic anastomotic ease and quality were significantly improved when three-dimensional visualization and curved endoscopic instruments were employed. Telemanipulation enhanced the process and provided the best operative results with regard to time required to construct the anastomosis, as well as ease and quality.

CONCLUSIONS

Totally endoscopic anastomosis is feasible using currently available technology. Three-dimensional visualization and robotic telemanipulation significantly facilitate anastomosis construction and will likely benefit clinical operative outcome.

Off-pump surgery decreases postoperative complications and resource utilization in the elderly

BACKGROUND

Bypass surgery in the elderly (age >70 years) has increased mortality and morbidity, which may be a consequence of cardiopulmonary bypass. We compare the outcomes of a cohort of elderly off-pump coronary artery bypass (OPCAB) patients with elderly conventional coronary artery bypass grafting (CABG) patients.

METHODS

Chart and provincial cardiac care registry data were reviewed for 30 consecutive elderly OPCAB patients (age 74.7 +/- 4.2 years) and 60 consecutive CABG patients (age 74.9 +/- 4.1 years, p = 0.82) with similar risk factor profiles: Parsonnet score 17.2 +/- 8.1 (OPCAB) versus 15.6 +/- 6.5 (CABG), p = 0.31; and Ontario provincial acuity index 4.5 +/- 1.9 (OPCAB) versus 4.3 +/- 2.0 (CABG), p = 0.65.

RESULTS

Mean hospital stay was 6.3 +/- 1.8 days for OPCAB patients and 7.7 +/- 3.9 days for CABG patients (p < 0.05). Average intensive care unit stay was 24.0 +/- 10.9 h for OPCAB patients versus 36.6 +/- 33.5 h for CABG patients (p < 0.05). Atrial fibrillation occurred in 10.0% of OPCAB patients and 28.3% of CABG patients (p < 0.05). Low output syndrome was observed in 10% of OPCAB patients and 31.7% of CABG patients (p < 0.05). Cost was reduced by $1,082 (Canadian) per patient in the OPCAB group. Postoperative OPCAB graft analysis showed 100% patency.

CONCLUSIONS

OPCAB is safe in the geriatric population and significantly reduces postoperative morbidity and cost.

The role of donor age and ischemic time on survival following orthotopic heart transplantation

BACKGROUND

The advances in immunotherapy, along with a liberalization of eligibility criteria have contributed significantly to the ever increasing demand for donor organs. In an attempt to expand the donor pool, transplant programs are now accepting older donors as well as donors from more remote areas. The purpose of this study is to determine the effect of donor age and organ ischemic time on survival following orthotopic heart transplantation (OHT).

METHODS

From April 1981 to December 1996 372 adult patients underwent OHT at the University of Western Ontario. Cox proportional hazards models were used to identify predictors of outcome. Variables affecting survival were then entered into a stepwise logistic regression model to develop probability models for 30-day- and 1-year-mortality.

RESULTS

The mean age of the recipient population was 45.6 +/- 12.3 years (range 18-64 years: 54 < or = 30; 237 were 31-55; 91 > 56 years). The majority (329 patients, 86.1%) were male and the most common indications for OHT were ischemic (n = 180) and idiopathic (n = 171) cardiomyopathy. Total ischemic time (TIT) was 202.4 +/- 84.5 minutes (range 47-457 minutes). In 86 donors TIT was under 2 hours while it was between 2 and 4 hours in 168, and more than 4 hours in 128 donors. Actuarial survival was 80%, 73%, and 55% at 1, 5, and 10 years respectively. By Cox proportional hazards models, recipient status (Status I-II vs III-IV; risk ratio 1.75; p = 0.003) and donor age, examined as either a continuous or categorical variable ([age < 35 vs > or = 35; risk ratio 1.98; p < 0.001], [age < 50 vs > or = 50; risk ratio 2.20; p < 0.001], [age < 35 vs 35-49 versus > or = 50; risk ratio 1.83; p < 0.001]), were the only predictors of operative mortality. In this analysis, total graft ischemic time had no effect on survival. However, using the Kaplan-Meier method followed by Mantel-Cox logrank analysis, ischemic time did have a significant effect on survival if donor age was > 50 years (p = 0.009). By stepwise logistic regression analysis, a probability model for survival was then developed based on donor age, the interaction between donor age and ischemic time, and patient status.

CONCLUSIONS

Improvements in myocardial preservation and peri-operative management may allow for the safe utilization of donor organs with prolonged ischemic times. Older donors are associated with decreased peri-operative and long-term survival following. OHT, particularly if graft ischemic time exceeds 240 minutes and if these donor hearts are transplanted into urgent (Status III-IV) recipients.

Safety and cost-effectiveness of MIDCABG in high-risk CABG patients

BACKGROUND

Myocardial revascularization without cardiopulmonary bypass has been proposed as a potential therapeutic alternative in high-risk patients undergoing coronary artery bypass grafting. To evaluate this possibility we compared 15 high-risk (HR) patients in whom minimally invasive direct coronary artery bypass grafting was used as the method of revascularization with 41 consecutive patients who underwent conventional coronary artery bypass grafting during 1 month.

METHODS

Patients undergoing myocardial revascularization without cardiopulmonary bypass were significantly older than their low-risk (LR) counterparts (72.2 +/- 11.6 versus 63.3 +/- 9.7 years, p = 0.006). The demographic profile for HR versus LR patients was as follows: female patients, 60.0% versus 26.8%, p = 0.02; diabetes, 20.0% versus 24.4%, p = 0.7; prior stroke, 33.3% versus 7.4%, p = 0.03; chronic obstructive pulmonary disease, 60.0% versus 9.8%, p < 0.0001; peripheral vascular disease, 33.3% versus 12.2%, p = 0.03, congestive heart failure, 26.6% versus 9.8%, p = 0.09; impaired left ventricular (ejection fraction < 0.40), 40.0% versus 17.0%, p = 0.07; urgent operation, 86.6% versus 46.3%, p < 0.0001; and redo operation, 20.0% versus 0%, p = 0.003.

RESULTS

There were no deaths in the HR group and one death in the LR group. The average intensive care unit stay was 1.1 +/- 0.5 days in HR patients versus 1.6 +/- 1.6 days in LR individuals (p = 0.2), and the average hospital stay was 6.1 +/- 1.8 versus 7.3 +/- 4.4 days, respectively (p = 0.3). We used an acuity risk score index developed by the Adult Cardiac Care Network of Ontario to predict outcome in the HR group. The expected intensive care unit stay in HR patients was 4.1 +/- 1.2 days (versus the observed stay of 1.1 +/- 0.5 days, p < 0.0001), and the expected hospital stay was 12.5 +/- 1.5 days (versus the observed stay of 6.1 +/- 1.8 days, p < 0.0001). The expected mortality in the HR group was 6.1% versus 0%, p = 0.3. A cost regression model was used to examine predicted versus actual cost (in Canadian dollars) for the HR patient cohort (based on Ontario Ministry of Health funding). The expected cost for the HR cohort would have been $11,997 per patient. In contrast, the average cost for these 15 patients was $5,997 per patient, an estimated cost saving of 50%.

CONCLUSIONS

Myocardial revascularization without cardiopulmonary bypass appears to be a safe and cost-effective therapeutic modality for HR patients requiring myocardial revascularization.

Reversal of pulmonary arteriovenous malformation after diversion of anomalous hepatic drainage

Pulmonary arteriovenous malformation can occur in up to 25% of patients after a classic Glenn shunt. Although unproven, exclusion of hepatic venous blood from the lungs has been proposed as a possible cause. We present a patient born with anomalous hepatic venous drainage into the left atrium with an intact atrial septum in whom pulmonary arteriovenous malformation developed in childhood. This was reversed after diversion of the hepatic venous drainage to the right atrium, supporting exclusion of hepatic venous flow as the cause of pulmonary arteriovenous malformation. The association with the hepatopulmonary syndrome is discussed.

Phase I safety and pharmacokinetic studies of brequinar sodium after single ascending oral doses in stable renal, hepatic, and cardiac allograft recipients

Brequinar sodium (BQR), a substituted 4-quinoline carboxylic acid, was in clinical development in combination with cyclosporine (CsA) as a potentially effective therapy for the treatment and prophylaxis of rejection in organ transplant patients. This phase I study was performed in stable renal, hepatic, and cardiac transplant patients receiving CsA and prednisone maintenance therapy for immunosuppression. The pharmacokinetic objectives of this study were to characterize the pharmacokinetics of (a) single oral 0.5- to 4-mg/kg doses of BQR when given in combination with CsA and prednisone to stable renal, hepatic, and cardiac transplant patients and (b) steady-state oral doses of CsA, with and without single oral doses of BQR. In all three patient populations, the pharmacokinetics of BQR were characterized by a lower oral clearance (12-19 mL/min) than that seen in previous studies in patients with cancer (approximately 30 mL/min at similar doses) and a long terminal half life (13-18 hrs). This slower oral clearance for BQR could be due either to a drug interaction between BQR and CsA or to altered clearance or metabolic processes in patients with transplants. Steady-state CsA trough levels and the oral clearance of CsA were not affected by BQR coadministration. Among the three transplant populations, the cardiac transplant patients had lower oral clearance values of BQR and of CsA. The cause of this lower clearance is not known. Safety results indicate that BQR was well tolerated by this patient population.