Minimally Invasive versus Open Mitral Valve Surgery a Consensus Statement of the International Society of Minimally Invasive Coronary Surgery (ISMICS) 2010

Objective

The purpose of this consensus conference was to deliberate the evidence regarding whether minimally invasive mitral valve surgery via thoracotomy improves clinical and resource outcomes compared with conventional open mitral valve surgery via median sternotomy in adults who require surgical intervention for mitral valve disease.

Methods

Before the consensus conference, the consensus panel reviewed the best available evidence up to March 2010, whereby systematic reviews, randomized trials, and nonrandomized trials were considered in descending order of validity and importance. The accompanying meta-analysis article in this issue of the Journal provides the systematic review of the evidence. Based on this systematic review, evidence-based statements were created for pre-specified clinical questions, and consensus processes were used to derive recommendations. The American Heart Association/American College of Cardiology system was used to label the level of evidence and class of each recommendation.

Results and Conclusions

Considering the underlying level of evidence, and notwithstanding the limitations of the evidence base (retrospective studies with important differences in baseline patient characteristics, which may produce bias in results of the evidence syntheses), the consensus panel provided the following evidence-based statements and overall recommendation: In patients with mitral valve disease, minimally invasive surgery may be an alternative to conventional mitral valve surgery (Class IIb), given that there was comparable short-term and long-term mortality (level B), comparable in-hospital morbidity (renal, pulmonary, cardiac complications, pain perception, and readmissions) (level B), reduced sternal complications, transfusions, postoperative atrial fibrillation, duration of ventilation, and intensive care unit and hospital length of stay (level B). However, this should be considered against the increased risk of stroke (2.1% vs 1.2%) (level B), aortic dissection (0.2% vs 0%) (level B), phrenic nerve palsy (3% vs 0%) (level B), groin infections/complications (2% vs 0%) (level B), and, prolonged cross-clamp time, cardiopulmonary bypass time, and procedure time (level B). The available evidence consists almost entirely of observational studies and must not be considered definitive until future adequately controlled randomized trials further address the risk of stroke, aortic complications, phrenic nerve complications, pain, long-term survival, need for reintervention, quality of life, and cost-effectiveness.

Minimally invasive direct coronary artery bypass and off-pump coronary artery bypass surgery: anesthetic considerations

Many new surgical technologies are being developed, with the overall aim of improving outcomes. One common feature of many new technologies is that they offer a safer approach than previous techniques; one of the greatest forces for change over the last 30 years is risk reduction. Cardiac surgery risk has been effectively undercut by percutaneous-based procedures, which have offered dramatic reductions in risk--at least in the short term. Beating heart techniques, whether minimally invasive direct coronary artery bypass (MIDCAB), off-pump coronary artery bypass surgery (OPCAB), or in other forms, such as percutaneous valve replacement, are likely to dramatically increase over the next decade. What role OPCAB and MIDCAB techniques will play in this new era is anyone's guess.

Impact of the opening of a specialized cardiac surgery recovery unit on postoperative outcomes in an academic health sciences centre

PURPOSE

It is controversial as to whether cardiac surgery patients are optimally managed in a mixed medical-surgical intensive care unit (ICU) or in a specialized postoperative unit. We conducted a prospective cohort study in an academic health sciences centre to compare outcomes before and following the opening of a specialized cardiac surgery recovery unit (CSRU) in April 2005.

METHODS

The study cohort included 2,599 consecutive patients undergoing coronary artery bypass grafting (CABG), valve and combined CABG-valve procedures from April 2004 to March 2006. From April 2004 to March 2005 (year 1) all patients received postoperative care in mixed medical-surgical ICUs at two different sites staffed by critical care consultants, fellows and residents. From April 2005 until March 2006 (year 2) patients were cared for in a newly-established CSRU on one site staffed by cardiac anesthesiology fellows, a nurse practitioner and consultants in critical care, cardiac anesthesiology and cardiac surgery. The effect of this change on in-hospital mortality, the incidence of ten major postoperative complications, postoperative ventilation hours, readmission rates and case cancellations due to a lack of capacity was assessed using Chi-square or Wilcoxon tests, where appropriate.

RESULTS

Coronary artery bypass grafting, valve and combined CABG-valve mortality rates were similar in years 1 and 2. There was a significant reduction in the composite major complication rate (16.3% to 13.0%, P=0.02) and in median postoperative ventilation hours (8.8 vs 8.0 hr, P=0.005) from year 1 to 2. On multivariable logistic regression analysis, the pre-merger interval (year 1) was a significant independent predictor of the occurrence of death or major complications.

CONCLUSION

A specialized CSRU with a multi-disciplinary consultant model was associated with stable or improved outcomes postoperatively, when compared to a mixed medical- surgical ICU model of cardiac surgical care.

A phase II dose-response study of hemoglobin raffimer (Hemolink) in elective coronary artery bypass surgery

BACKGROUND

We performed this study to determine the dose-response of hemoglobin raffimer administered in conjunction with intraoperative autologous donation in patients undergoing coronary artery bypass grafting surgery. A secondary objective was to evaluate hemoglobin raffimer for reducing the incidence of allogeneic red blood cell transfusions.

METHODS

This was a phase II, single-blind, multicenter, placebo-controlled, open-label study. Patients undergoing coronary artery bypass grafting with cardiopulmonary bypass and intraoperative autologous donation were randomized to receive a single dose of hemoglobin raffimer or control (10% pentastarch). Patients were sequentially enrolled in a dose block of 250, 500, 750, and 1000 mL.

RESULTS

Sixty patients received hemoglobin raffimer (n = 30) or control (n = 30). Hemoglobin raffimer was well tolerated. Most (98%) adverse events were mild or moderate in severity. There was an expected dose-dependent increase in the incidence of blood pressure increases and jaundice in hemoglobin raffimer-treated patients. In a dose-pooled analysis of hemoglobin raffimer versus control, increased blood pressure (43% vs 17%), nausea (37% vs 33%), and atrial fibrillation (37% vs 17%) were the most frequently reported adverse events. All serious adverse events were considered unrelated or unlikely to be related to study drug. No hemoglobin raffimer-treated patient required an intraoperative allogeneic red blood cell transfusion, compared with 5 (17%) pentastarch-treated patients (P =.052). This advantage of hemoglobin raffimer was maintained at 24 hours after surgery (7% vs 37%; P =.010) and up to 5 days after surgery (10% vs 47%; P =.0034).

CONCLUSIONS

Hemoglobin raffimer was not associated with any serious adverse events in patients undergoing primary coronary artery bypass grafting with cardiopulmonary bypass and intraoperative autologous donation in a dose-response study up to 1000 mL. Hemoglobin raffimer was effective in facilitating decreased exposure or avoidance of allogeneic red blood cell transfusions when used in conjunction with intraoperative autologous donation.

Randomized assessment of resource use in fast-track cardiac surgery 1-year after hospital discharge

BACKGROUND

The authors assessed the safety and resource use associated with fast-track cardiac anesthesia (FTCA) after coronary artery bypass graft surgery (CABG) over a 1-yr period.

METHODS

One hundred twenty patients were initially randomized to FTCA (n = 60) or conventional anesthetic (n = 60) for primary elective CABG surgery. Patients were followed for 1-yr after index surgery through linkage to universal administrative databases. Acute care hospital readmission rates and length of stay (LOS) and the downstream use of health resources were compared. Resource use was analyzed as use of hospital and rehabilitation center bed-days, expenditures on physician services, and use of cardiac drugs.

RESULTS

There were no deaths during the 1-yr follow-up after initial discharge; 15 (25%) patients from both groups were readmitted to acute care hospitals in the follow-up period. The mean LOS for acute care readmission was 0.3 (1.0) in the FTCA and 1.6 (6.3) days in the conventional group at 3 months; P= 0.01, 95% CI (0.1, 5.7) and 0.8 (1.8) and 2.9 (9.6) days at 12 months; P= 0.01, 95% CI (0.2, 7.5). Two (3.3%) patients in the FTCA group and 9 (15%) patients in the conventional group were transferred to rehabilitation facilities. The LOS was 0.3 (1.5) and 2.3 (5.7) days respectively; P= 0.001, 95% CI (0.6, 4.0). Specialist visits were more frequent in the FTCA group 6.2 (13.2) versus 1.9 (2.2) visits respectively; P= 0.002, 95% CI (-9.0, -1.3). Percentage reduction of FTCA cost was 68% at 3 months, P= 0.0002 and 49.5% at 1-yr, P= 0.004 after index hospital discharge.

CONCLUSIONS

Fast-track cardiac anesthesia is a safe practice that decreases resource use for a 1-yr period after index hospitalization.

Oxygen therapeutics (blood substitutes) in cardiac surgery

PURPOSE OF REVIEW

Discuss and summarize recent published literature related to the use of 'blood substitutes' in cardiac surgery patients.

RECENT FINDINGS

Concerns about safety, inventory and the cost of allogenic blood transfusion have led to the continued interest to find an ideal oxygen carrier 'blood substitute' for cardiac surgery patients. Two classes of oxygen therapeutics 'blood substitutes' are being investigated: (1) perfluorocarbons are synthetic fluorinated hydrocarbons which increase dissolved oxygen in the fluid phase and (2) hemoglobin-based oxygen carriers, modified to improve oxygen dissociation properties and side effects profiles of free hemoglobin. Hemoglobin-based oxygen carriers from bovine and human sources are being tested in phase III trials in cardiac surgery patients as well as a variety of other surgical and nonsurgical settings. Recombinant human hemoglobin and encapsulated hemoglobins of any source are emerging. Safety and cost effectiveness are being evaluated for their use as an alternative to blood transfusion or along with other strategies of blood conservation in cardiac surgery.

SUMMARY

One hemoglobin-based oxygen carrier (Hemopure) has been approved for use in humans in South Africa as well as another hemoglobin-based oxygen carrier (Gelenpol) and a perfluorocarbon (Perfluoron) in Russia. Phase III trials in Europe and North America will be concluded very soon. We anticipate seeing one or two products approved in North America and Europe by the year 2003/2004.

Postoperative atrial fibrillation: a comparison of off-pump coronary artery bypass surgery and conventional coronary artery bypass graft surgery

OBJECTIVE

To compare the incidence and pattern of onset of postoperative atrial fibrillation (AF) in patients undergoing coronary artery bypass graft (CABG) surgery with and without cardiopulmonary bypass (CPB).

DESIGN

Retrospective, cohort-controlled study.

SETTING

University hospital and tertiary referral center.

PARTICIPANTS

A group of 108 consecutive patients who underwent primary off-pump coronary artery bypass (OP-CAB) surgery and a control group of 100 patients who underwent CABG surgery with CPB. All patients underwent surgery between January and September 1999.

INTERVENTIONS

Patients in the OP-CAB surgery group were operated on by either of 2 surgeons. The CABG surgery group was drawn from the general pool of patients operated on by 1 of 10 surgeons. All patients underwent median sternotomy and received standard anesthesia and intensive care unit management for this institution.

MEASUREMENTS AND MAIN RESULTS

Data from 99 OP-CAB surgery patients (data incomplete in 9 patients) were compared with data from 100 CABG surgery patients. General demographics were similar except the CABG surgery group received a higher mean number of distal anastomoses (3.3 v 3.0; p = 0.028) The incidence of AF was similar in both groups (OP-CAB surgery, 25% v CABG surgery, 18%; p = 0.228). The peak incidence of AF was postoperative day 2 in both groups. The median hospital length of stay was increased in patients developing AF.

CONCLUSION

Avoiding CPB does not seem to reduce the incidence of postoperative AF in CABG surgery. The similar time distribution of onset of AF in OP-CAB surgery patients and CABG surgery patients may point toward a common cause.