Minimally invasive versus conventional sternotomy for Mitral valve repair: protocol for a multicentre randomised controlled trial (UK Mini Mitral).

INTRODUCTION: Numbers of patients undergoing mitral valve repair (MVr) surgery for severe mitral regurgitation have grown and will continue to rise. MVr is routinely performed via median sternotomy; however, there is a move towards less invasive surgical approaches.There is debate within the clinical and National Health Service (NHS) commissioning community about widespread adoption of minimally invasive MVr surgery in the absence of robust research evidence; implementation requires investment in staff and infrastructure.The UK Mini Mitral trial will provide definitive evidence comparing patient, NHS and clinical outcomes in adult patients undergoing MVr surgery. It will establish the best surgical approach for MVr, setting a standard against which emerging percutaneous techniques can be measured. Findings will inform optimisation of cost-effective practice. METHODS AND ANALYSIS: UK Mini Mitral is a multicentre, expertise based randomised controlled trial of minimally invasive thoracoscopically guided right minithoracotomy versus conventional sternotomy for MVr. The trial is taking place in NHS cardiothoracic centres in the UK with established minimally invasive mitral valve surgery programmes. In each centre, consenting and eligible patients are randomised to receive surgery performed by consultant surgeons who meet protocol-defined surgical expertise criteria. Patients are followed for 1 year, and consent to longer term follow-up.Primary outcome is physical functioning 12 weeks following surgery, measured by change in Short Form Health Survey (SF-36v2) physical functioning scale. Early and 1 year echo data will be reported by a core laboratory. Estimates of key clinical and health economic outcomes will be reported up to 5 years.The primary economic outcome is cost effectiveness, measured as incremental cost per quality-adjusted life year gained over 52 weeks following index surgery. ETHICS AND DISSEMINATION: A favourable opinion was given by Wales REC 6 (16/WA/0156). Trial findings will be disseminated to patients, clinicians, commissioning groups and through peer reviewed publication. TRIAL REGISTRATION NUMBER: ISRCTN13930454.

Choice of conduit for coronary artery bypass grafting in poor ventricles.

BACKGROUND: advantages in the use of arterial grafts for coronary artery revascularizations have been reported previously. OBJECTIVES: we aimed to compare the outcome and survival rates of different conduits in patients with poor ventricular function (ejection fraction<30%). METHODS: in a 10-year period, 979 patients with an ejection fraction<30%, who underwent isolated first-time coronary artery bypass grafting, were divided into in 3 groups: (A) total arterial grafts (n=257), (B) total vein grafts (n=76), and (C) left internal mammary artery and vein grafts (n=610). Multivariate logistic regression was used to assess the effect of graft type on mortality, while adjusting for patient and disease characteristics. Hospital mortality and 5-year survival rates were compared among the groups. RESULTS: hospital mortality was 8.9% for group A, 11.8% for group B, and 5.7% for group C. Mortality at 5 years was 27.2% for group A, 42.3% for group B, and 28.7% for group C. After risk adjustment, hospital mortality and mid- and long-term mortality showed no significant differences among the groups. CONCLUSIONS: patients with poor ventricular function have a high mortality rate in both the short- and long-term with any type of conduit. Mortality rates with total arterial grafts and vein plus arterial grafts were comparable before and after risk adjustment.

A comparison of outcome in patients with preoperative atrial fibrillation and patients in sinus rhythm.

BACKGROUND: Approximately 10% to 15% of patients undergoing cardiac operations suffer from atrial fibrillation (AF) at the time of surgery. The current risk stratification methods do not include preoperative arrhythmias. The aim of this study was to assess the effect of preoperative AF on the immediate postoperative outcome of patients undergoing cardiac surgery as well as in the midterm and long-term outcomes. METHODS: We reviewed patient data for our institution for a 10-year period; a total of 14,320 patients undergoing any cardiac operation were included; 12,395 (86.5%) had sinus rhythm preoperatively and 1,925 (13.5%) were in persistent AF. After propensity matching and adjusting for the preoperative and operative characteristics, 1,800 patients remained in each group and were compared. RESULTS: Before and after adjusting for the preoperative and operative characteristics, inotropic support, ventilation time, renal failure, stroke, and surgical wound infection rates were all significantly higher for the patients with AF (p < 0.001). Intensive care unit stay and hospital stay as well as in-hospital mortality were also significantly higher among the patients with AF compared with the sinus rhythm group (p < 0.001). At 30 days, 5-year and 10-year mortality rates in the AF group were significantly higher compared with those in sinus rhythm group (p < 0.001). CONCLUSIONS: Atrial fibrillation preoperatively is associated with a higher incidence of postoperative complications. This arrhythmia is an important variable that appears to have been excluded from the current risk stratification systems. Our experience suggests that AF should be considered in the development/update of risk-stratifying methodologies to improve the predictive accuracy.

Do patients in congestive cardiac failure undergoing cardiac surgery demonstrate worse outcomes compared with those with a history of cardiac failure?

OBJECTIVES: Cardiac surgery in patients with symptoms of congestive cardiac failure (CCF) carries a significant risk of mortality and morbidity. Except for emergencies and in unstable cases, the recommendation has been to delay the operation until the patient is fully recovered. The objective of this study was to determine the consequences of cardiac surgery in patients with acute decompensated heart failure and to compare their outcomes with the results of the operation in patients with previous CCF. METHODS: We compared the outcomes of patients with CCF (n = 707) at the time of cardiac surgery (valve replacement or coronary artery bypass grafting [CABG]) with those with a history of CCF (n = 1583). The EuroSCORE was significantly higher in CCF patients (P < .001). Impaired renal function was also more commonly observed in patients with CCF (P < .001). After adjusting for preoperative characteristics, we compared the 2 groups with respect to postoperative complications, postoperative creatine kinase MB values, and in-hospital mortality. RESULTS: Before adjusting for preoperative characteristics, we found that in-hospital mortality (15.5%) and postoperative complications, such as arrhythmias (31%), renal failure (19%), stroke (4.7%), and myocardial infarction (MI) (3%), were significantly higher in the CCF group than in those with a previous history of CCF. When the patients were matched for preoperative characteristics, the rates of postoperative MI and arrhythmia were the main complications that were significantly higher in the CCF group, compared with the patients with previous CCF. The 2 groups were not significantly different with respect to in-hospital mortality. The results were not affected by the type of procedure (valve or CABG), and the main factor influencing mortality was the EuroSCORE. CONCLUSION: Despite the significant risk of mortality and morbidity in patients with current CCF, cardiac surgery to reverse the cause should not be delayed in these patients, because doing so may lead to further deterioration. Other risk factors, however, should be taken into consideration on an individual basis.

Comparing the outcome of on-pump versus off-pump coronary artery bypass grafting in patients with preoperative atrial fibrillation.

OBJECTIVES: Around 5-15% of patients undergoing coronary artery bypass grafting (CABG) suffer from preoperative/pre-existing atrial fibrillation (PAF). This is a benign arrhythmia but can affect the outcome of the surgery. The aim of this study was to assess the effect of PAF on the immediate postoperative course of patients undergoing on-pump (ONCAB) vs. off-pump (OPCAB) CABG. METHODS: Over a 10-year period, data were prospectively entered into the database of our institution. A total of 10,461 patients underwent CABG, of whom 477 (4.6%) were in PAF. We analyzed these patients in two separate groups: group A (n=310) who underwent ONCAB and group B (n=167) who underwent OPCAB. After 4:1 propensity matching and adjusting for the preoperative and operative characteristics of these two groups with patients in SR (sinus rhythm), early, mid- and long-term outcomes of PAF patients were analyzed. RESULTS: After adjusting for preoperative characteristics, postoperative complications were significantly higher in patients who had ONCAB when there was PAF compared to those in SR (P<0.001). In the OPCAB patients, on the other hand, there was no statistically significant difference in the postoperative complications between the patients with preoperative SR or PAF. In-hospital and short-term mortality were no different in the PAF group undergoing OPCAB compared to those in SR; however, the mid- and long-term survival rates in PAF patients who underwent OPCAB/ONCAB were worse compared than was seen in SR. CONCLUSIONS: PAF is associated with a higher incidence of postoperative complications. Our results have demonstrated that patients in PAF undergoing ONCAB are more susceptible to the postoperative complications compared to those in SR. However, there were no differences in mid- and long-term outcomes.

Atrial fibrillation postcardiac surgery: a common but a morbid complication.

OBJECTIVES: Despite all the advances in cardiac surgery, atrial fibrillation (AF) remains a common postoperative complication with unclear predisposing factors. Postoperative AF is often a short-lived and a self-limiting condition, but can result in debilitating and even lethal consequences. The aim of this study is to assess the effect of AF on patients postcardiac surgery. METHODS: In this retrospective study, we prospectively reviewed patient data for our institution for a 10-year period; a total of 17,379 patients with preoperative sinus rhythm (SR) who underwent cardiac surgery were included, of which 4984 (28.7%) had developed postoperative AF for any length of time. After propensity matching for the preoperative characteristics between the two groups; the group with AF and the group who remained in SR, postoperative complications, in-hospital mortality, mid-term survival rate (five years), and long-term survival rate (10 years) were compared. RESULTS: Before and after adjusting for the preoperative characteristics and type of the operation, postoperative complications, such as renal failure, surgical wound infection, stroke and myocardial infarction were significantly higher in the AF group compared to the SR group (P < 0.001). Inotropic support, use of intra-aortic balloon pump, and ventilation time were also considerably higher in the AF patients (P < 0.001). In-hospital mortality was also higher in the AF group. Likewise, 30-day, mid-term and long-term mortality rates were found to be considerably higher in the AF group. CONCLUSIONS: Despite all the modern anti-arrhythmic drugs, the incidence of AF remains unchanged. Patients who develop AF postcardiac surgery show a significantly worse outcome compared to those without AF. This study also highlights the importance of anticoagulation in AF to prevent the devastating consequences as a result of a cerebral stroke. We believe that not only immediate treatment of AF postoperatively should be implemented, but also measures should be taken to identify the risk factors of AF and to prevent AF postcardiac surgery.

The use of cell salvage in routine cardiac surgery is ineffective and not cost-effective and should be reserved for selected cases.

The reported benefits of intraoperative cell salvage are decreased requirement for blood transfusion and cost-effectiveness. This study was designed to challenge this hypothesis. We assessed intraoperative blood loss and the use of cell saver in our institution. In <7% of cases the volume of blood loss was sufficient enough to be washed and returned. We conclude that the routine use of cell savers in all cardiac operations affords no benefit and consumes additional revenue. We recommend that the system only be considered in selected high-risk cases or complex procedures.

Does off-pump coronary artery revascularization improve the long-term survival in patients with ventricular dysfunction?

OBJECTIVES: Coronary artery revascularization with cardiopulmonary bypass (ONCAB) has been reported to carry several risks for patients with poor left ventricular (LV) function (ejection fraction <30%). Off-pump CABG (OPCAB) has been proposed to result in a better outcome, but mid- and long-term survival rates have never been compared. The aim of this study is to assess the effect of cardiopulmonary bypass on this group of patients. METHODS: In a 10-year period, a total of 934 patients with poor LV function undergoing isolated first-time coronary artery bypass graft were studied. They were divided into two groups, the ONCAB group, with 528 patients, and the OPCAB group with 406 patients. The EuroSCORE was significantly higher in the OPCAB group (P=0.049). After adjusting for the preoperative characteristics, postoperative complications, in-hospital mortality, mid-term survival rate (five years), and long-term survival rate (10 years) were compared. RESULTS: The average number of grafts was 3.7 in the ONCAB group and 3.1 in the OPCAB group (P<0.001). Postoperative complications of ONCAB and OPCAB groups such as; atrial fibrillation (29.6% vs. 28.6%), renal failure (9.3% vs. 9.6%), stroke (2.3% vs. 0.7%), and perioperative myocardial infarction (MI) (3.8% vs. 2.0%), were comparable between groups. Length of intensive care unit stay, hospital stay and ventilation time were considerably shorter in the OPCAB group (P<0.05). The incidence of wound infection was also lower in the OPCAB patients (P<0.05). After adjusting for the preoperative characteristics the incidence of most postoperative complications remained the same between the two groups, except for MI, which was lower in the OPCABs (P<0.04). Despite a lower number of proximal anastomoses in the OPCAB patients, the rate of stroke remained the same between the OPCAB and ONCAB patients (0.09% vs. 1.6%). In-hospital mortality was higher in ONCAB compared to OPCAB (7.8% vs. 5.7%), but this difference did not reach statistical significance (P=0.21). Likewise, mid-term and long-term survival rates were similar even with matched preoperative characteristics. However, re-intervention rate was found to be higher in the OPCABs (P<0.001). CONCLUSIONS: Despite the reported benefits of OPCAB, there was no significant influence on the in-hospital mortality, mid-term survival or long-term survival in patients with LV dysfunction. With adequate myocardial protection in ONCAB and complete revascularization in OPCAB, similar results are achievable.

Does off-pump surgery offer benefit in high respiratory risk patients? A respiratory risk stratified analysis in a propensity-matched cohort.

OBJECTIVE: The role of off-pump surgery in high respiratory risk patients remains unclear. In this study, we aim to evaluate the effect of off-pump surgery on high respiratory risk patients. METHODS: To achieve comparative groups, a five digit propensity score matching with 18 pre-operative variables was performed on 4406 consecutive CABG patients operated between January 2000 and September 2003. Respiratory risk stratification was performed with the following variables: (1) FEV(1)<65% of predicted, (2) patients>75 years old, (3) history of current smoking, (4) body mass index more than 40 kg/m(2) and (5) NYHA class IV dyspnoea in combination with current respiratory medication. The presence of two or more variables defined high risk. The primary end point was post-operative ventilation time. We also compared alveolar arterial gradients (A-a gradient) on admission to ITU, 2 and 4h using Friedman rank time analysis. RESULTS: We matched 1353 off-pump patients with 1353 unique on-pump patients. Respiratory risk stratified selection resulted in 73 off-pump and 55 on-pump high-risk patients. In the off-pump group, four (5.5%) patients had more than two selection criteria, compared to one (1.8%) for on-pump patients (p=0.29). The off-pump group had more patients with FEV1<65% compared to on-pump: 65 (89.0%) versus 40 (72.7%); p=0.017. The median ventilation time was significantly shorter for off-pump patients (7h [IQR: 5-14] vs 12h [IQR: 7-18], p=0.003). In the off-pump group, three (4.1%) patients had a ventilation time>48 h compared to eight (14.6%) in the on-pump group, p=0.037. A-a gradient measurements on admission to ITU were lower in off-pump patients (median: 182.3 [IQR: 126.6-216.2]) compared to on-pump patients (median: 194.7 [IQR 139.7-245.4], p=0.064). CONCLUSION: Off-pump surgery offers benefit to high respiratory risk patients by reducing post-operative ventilation time. Off-pump patients also have lower A-a gradients in the early post-operative period but this failed to reach significance.

A randomized comparison of three methods of analgesia for chest drain removal in postcardiac surgical patients.

Sixty-six patients scheduled for coronary artery bypass graft and/or valve surgery were recruited in a prospective, randomized study designed to compare the effectiveness of three analgesic regimens for chest drain removal. Patients were randomized to receive 0.1 mg/kg IV morphine, 20 mL of 0.5% bupivacaine infiltrated subcutaneously, or inhaled 50% nitrous oxide in oxygen (Entonox) via a demand valve. We assessed pain by measuring visual analog scale pain scores before and during drain removal. Median (25th, 75th centile) visual analog scale pain scores associated with drain removal in the bupivacaine, Entonox, and morphine groups were 9.5 mm (3, 18 mm), 37.0 mm (13, 56 mm), and 15.0 mm (7, 27 mm), respectively. The pain scores were higher in the Entonox group compared with the bupivacaine group (P=0.005) and the morphine group (P=0.047). Differences between baseline and drain-removal scores were -0.5 mm (-13, 7 mm), +10 mm (1, 29 mm), and -3.0 mm (-11, 12 mm), respectively. There was no difference among groups in arterial blood pressure, heart rate, PaCO2, oxygenation, or sedation. Bupivacaine and morphine, unlike Entonox, produce lower pain scores associated with drain removal.