Endothelial activation after coronary artery bypass surgery : comparison between on-pump and off-pump techniques

Background - The effects of off-pump coronary artery bypass (OPCAB) surgery on endothelial cell activation are poorly understood. Endothelial cell adhesion molecules (CAMs) are expressed and released when the endothelium is activated. We compared plasma CAMs (E-selectin, ICAM-1 and VCAM-1) and HUVEC expression of the same CAMs when exposed to plasma taken before, during and after OPCAB or on-pump coronary surgery (CABG). Methods - Patients undergoing first time CABG (n = 10) or OPCAB (n = 10) had 6 blood samples taken before surgery and up to 24 h post-operatively. Plasma samples were assayed for E-selectin, ICAM-1 and VCAM-1. The same plasma samples were exposed to HUVEC cultures and cell-surface expression of E-selectin, ICAM-1 and VCAM-1 measured. Data are expressed as mean ± SEM of n subjects. Results - Plasma E-selectin was unchanged. Plasma ICAM-1 and VCAM-1 were elevated 24 h post-operatively in both groups (P < 0.01), with no differences between the groups. Twenty-four hours post-OPCAB plasma increased basal and IL-1β induced expression of endothelial VCAM-1 by 133 ± 16% and 140 ± 27% (P < 0.05), respectively. Plasma taken 3 h post-CABG decreased endothelial VCAM-1 expression by 76 ± 10% (P < 0.05). Peri-operative plasma had no effect on endothelial expression of E-selectin or ICAM-1 in either group. Conclusions - OPCAB and CABG with CPB appear to generate qualitatively different inflammatory responses with respect to endothelial activation, which may have clinical implications.8 page(s

Outcomes of surgical aortic valve replacement in octogenarians

Background: In the era of TAVI, there has been renewed interest in the outcomes of conventional AVR for high-risk patients. This study evaluates the short- and long-term outcomes of AVR in octogenarians. Methods: A retrospective review was performed of all 117 patients aged ≥80 years who underwent AVR, (isolated AVR (n= 60) or AVR + CABG (n= 57),) from August 2005 to February 2011 at Royal Prince Alfred Hospital and Strathfield Hospital. Univariate analysis was used to compare pre- and post-operative variables between younger and older subgroups (age 80-84, n= 82; age 85-89, n= 35 respectively). Long-term survival data was obtained from the National Death Index at the Australian Institute of Health and Welfare and survival curves were constructed using the Kaplan-Meier method. Results: The median age was 83 years (interquartile range, 81-85 years), 46.2% were females, the median EuroSCORE was 10.89% (interquartile range, 8.20-16.45%) and 16.2% of patients had a EuroSCORE ≥20%. The difference between subgroups for history of stroke was significant (p = .042). Post-operative complications included pleural effusion (12.8%), new renal failure (4.3%) and respiratory failure (4.3%). The rate of major adverse events was extremely low, with no cases of stroke. The 30-day mortality rate was 3.4%. There was a significant difference between subgroups for 30-day mortality (p = .007). 38.9% of patients were discharged home, 11.5% were transferred to another hospital and 38.9% spent a period of time in a rehabilitation institution post discharge. In terms of long-term survival, the six-month, one-year and three-year survival was 95.6%, 87.6% and 58.4% respectively. Conclusions: Surgical AVR yields excellent short- and long-term outcomes for potentially high-risk, elderly patients.9 page(s

Outcomes of aortic arch replacement surgery after previous cardiac surgery

Background: Aortic arch replacement is a potentially high-risk operation and in the re-operative setting has been found to be a risk factor for poor outcome, yet there is a dearth of published data specifically on this topic. The aim of the study was to review our unit's outcomes in this re-operative setting. Method: Data were collated for all patients who underwent aortic arch replacement surgery after previous cardiac surgery from January 1988 to November 2011. The patients were divided based primarily on elective versus non-elective and also early (≤2005) and late (≥2006) series. Results: Twenty-seven eligible patients (22 male; median age: 53.0 years; elective: 14, non-elective: 13) were identified. There was a mean period of 14.5 years between the first operation and the subsequent aortic arch replacement. The overall 30-day mortality rate was 22.2% - 0% elective and 46.2% non-elective (P = 0.004). Overall permanent neurological dysfunction was 21.7% - 28.6% elective and 11.1% non-elective (P = 0.463). There were 11 early-series patients and 16 late-series patients. For early-series patients, 90.9% were non-elective versus 18.8% in the late-series patients. The 30-day mortality rate was 54.5% early series versus 0% late series. Conclusion: Aortic arch replacement is high risk in the re-operative setting. These risks are even greater for non-elective procedures. This highlights the need for aggressive first-time surgery to reduce re-operative procedures and good long-term follow-up programmes to allow elective procedures if required.6 page(s

Evolution in the techniques and outcomes of aortic arch surgery : a 22 year single centre experience

Background: Aortic arch replacement is a complicated and high risk procedure. There have been many advances over recent years. We review the changes in our unit's techniques and outcomes over the past 22 years. Methods: Data were collated from databases and medical records for all patients who underwent aortic arch replacement surgery from January 1989 to December 2010. The patients were divided into two groups – Group A (1989–2005) and Group B (2006–2010). Data were analysed to compare early and late series patients' outcomes. Logistic regression was used to identify variables that predicted mortality. Results: Seventy-five eligible patients (56 males; mean age: 57.5 years; Group A: 40, Group B 35) were identified. There were great changes in the technique and the methods of cerebral protection. The overall mortality rate was 30.7% – Group A: 50% and Group B: 8.6% (p < 0.001). Overall permanent neurological dysfunction was 23.7% – Group A: 40% and Group B: 11.8% (p = 0.012). Cardiovascular disease and circulatory arrest time were significant predictors of mortality. Conclusions: Increased experience and volume and advances in techniques over 22 years have resulted in major improvements in outcomes for patients having aortic arch replacement, allowing the procedure to be performed with greatly improved outcomes.8 page(s

Off-pump coronary artery bypass surgery induces prolonged alterations to host neutrophil physiology

Persistent alteration to host polymorphonuclear cell (PMN) physiology has been demonstrated after cardiac surgery performed with cardiopulmonary bypass (CPB). However, to date, PMN physiology and function beyond the first 24 h have not been investigated after cardiac surgery performed without CPB (off-pump coronary artery bypass grafting [OPCAB]). Blood samples of 15 patients were collected preoperatively and on days 1, 3, and 5 after OPCAB. Expression of CD11b, CD18, CBRM1/5, and CD62L were assessed by flow cytometry under resting conditions and after stimulation with formyl methionyl-leucyl-phenylalanine (fMLF), and respiratory burst activity was also measured. Under resting conditions, PMN CD11b, CBRM1/5, and CD62L expressions were minimally altered by surgery. Compared with the response of preoperative PMNs, PMNs assayed on days 3 and 5 after OPCAB demonstrated a significantly blunted increase in the expression of CD11b and CBRM1/5 after fMLF, significantly diminished shedding of CD62L in response to platelet-activating factor and fMLF, and diminished superoxide production after stimulation on day 3. The alteration of PMN function after OPCAB implies that cardiac surgical trauma without CPB directly modulates host PMN physiology

Risk of reoperation for structural failure of aortic and mitral tissue valves

In order to assess the risk of reoperation in the case of a failing stented tissue valve, 259 patients (118 males, 141 females; mean age 60.1 ± 15.4 years) underwent redo valve replacement. Of these patients, 94 (36.3%) underwent redo aortic valve replacement (AVR), 105 (40.5%) redo mitral valve replacement (MVR), and 60 (23.2%) redo aortic and mitral valve replacement (DVR). Twenty patients (7.7%) had previous coronary artery bypass grafting (CABG); further CABG were performed in 32 cases (12.4%). Preoperatively, 216 patients (83.3%) were in NYHA functional class III or IV. Early mortality was (6.5%; n = 17). A higher preoperative NHYA status (p &lt;0.0004) and emergency surgery (p &lt;0.0001) were associated with an increased risk of operative death. Age at operation (p = 0.45), previous CABG (p = 0.45), position of the valve replaced (p = 0.2), type of implant (p = 0.06) and presence of coronary artery disease (p = 0.51) were not associated with a significant risk of operative mortality. A failing tissue valve may be replaced, with acceptable operative mortality and morbidity. The trend towards reducing the age at which tissue valve implantation is performed may be justified

Long term outcomes following Freestyle stentless aortic bioprosthesis implantation : an Australian experience

Background: The Freestyle stentless bioprosthesis (FSB) has been demonstrated to be a durable prosthesis in the aortic position. We present data following Freestyle implantation for up to 10 years post-operatively and compare this with previously published results. Methods: A retrospective cohort analysis of 237 patients following FSB implantation occurred at five Australian hospitals. Follow-up data included clinical and echocardiographic outcomes. Results: The cohort was 81.4% male with age 63.2±13.0 years and was followed for a mean of 2.4±2.3 years (range 0-10.9 years, total 569 patient-years). The FSB was implanted as a full aortic root replacement in 87.8% patients. The 30-day all cause mortality was 4.2% (2.0% for elective surgery). Cumulative survival at one, five and 10 years was 91.7±1.9%, 82.8±3.8% and 56.5±10.5%, respectively. Freedom from re-intervention at one, five and 10 years was 99.5±0.5%, 91.6±3.7% and 72.3±10.5%, respectively. At latest echocardiographic review (mean 2.3±2.1 years post-operatively), 92.6% had trivial or no aortic regurgitation. Predictors of post-operative mortality included active endocarditis, acute aortic dissection and peripheral vascular disease. Conclusions: We report acceptable short and long term outcomes following FSB implantation in a cohort of comparatively younger patients with thoracic aortic disease. The durability of this bioprosthesis in the younger population remains to be confirmed.7 page(s