Mitral Annular Plane Systolic Excursion: A Simple, Reliable Echocardiographic Parameter to Detect Left Ventricular Systolic Dysfunction in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting with Transesophageal Echocardiography.

OBJECTIVES: This study's objective was to test the hypothesis that transesophageal echocardiography (TEE)-based mitral annular plane systolic excursion (MAPSE) measurement is useful in perioperative settings to detect left ventricular (LV) systolic dysfunction in patients undergoing off-pump coronary artery bypass grafting (OPCAB). DESIGN: Retrospective observational study. SETTING: Tertiary-care level hospitals. PARTICIPANTS: The study comprised 116 patients undergoing OPCAB to obtain cutoffs of MAPSE to detect LV dysfunction. These cutoffs were validated in another 105 patients from 2 other institutions. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: In 116 patients who had undergone OPCAB during the study period with TEE monitoring, MAPSE was measured post hoc at the lateral and septal mitral (and average) annulus using the software tool M.mode.ify (http://www.ultrasoundoftheweek.com/M.mode.ify). Receiver operating curves were constructed to obtain cutoff values of MAPSE at the lateral and septal (and average) annulus of the mitral valve to predict LV systolic dysfunction, which was defined by an ejection fraction <52% for men and <54% for women as measured using the biplane method of disks. These cutoff values then were validated in another 105 patients. LV systolic dysfunction was present in 43% patients. Youden's index values of 9mm for lateral MPASE (area under the receiver operating curve [AUC] 0.93 [confidence interval {CI} 0.87-0.97]; p < 0.0001); 7mm for septal MAPSE (AUC 0.87 [CI 0.79-0.92]; p < 0.0001); and 9mm for average MAPSE (AUC 0.92 [CI 0.86-0.96]; p < 0.0001) were obtained. These cutoffs were statistically significant in the validation cohort (p < 0.0001) with an AUC of 0.84 (CI 0.75-0.90), sensitivity of 86.2%, specificity of 80.8%, positive predictive value of 84.8%, and negative predictive value of 82.6%. CONCLUSIONS: MAPSE is a simple, rapid, and reliable method to detect LV dysfunction using TEE in patients undergoing OPCAB. Its use as screening tool for LV dysfunction is recommended.

Evaluation of augmented pulse pressure variation using the Valsalva manoeuvre as a predictor of fluid responsiveness under open-chest conditions: A prospective observational study.

BACKGROUND: Pulse pressure variation (PPV) is a well known dynamic preload indicator of fluid responsiveness. However, its usefulness in open-chest conditions remains controversial. OBJECTIVE: We evaluated whether augmented PPV during a Valsalva manoeuvre can predict fluid responsiveness after sternotomy. DESIGN: A prospective, observational study. SETTING: Single-centre trial, study period from October 2014 to June 2015. PATIENTS: Forty-nine adult patients who underwent off-pump coronary arterial bypass grafting. INTERVENTION: After midline sternotomy, haemodynamic parameters were measured before and after volume expansion (6 ml kg of crystalloids). PPV was calculated both automatically (PPVauto) and manually (PPVmanual). For PPV augmentation, we performed Valsalva manoeuvres with manual holding of the rebreathing bag and constant airway pressure of 30 cmH2O for 10 s before fluid loading and calculated PPV during the Valsalva manoeuvre (PPVVM). MAIN OUTCOME MEASURES: The predictive ability of PPVVM for fluid responsiveness using receiver-operating characteristic curve analysis. Responders were identified when an increase in cardiac index of at least 12% occurred after fluid loading. RESULTS: Twenty-one patients were responders and 28 were nonresponders. PPVVM successfully predicted fluid responsiveness with an area under the curve (AUC) of 0.88 [95% confidence interval (95% CI) 0.75 to 0.95; sensitivity 91%, specificity 79%, P < 0.0001] and a threshold value of 55%. Baseline PPVauto and PPVmanual also predicted fluid responsiveness [AUC 0.75 (0.62 to 0.88); sensitivity 79%, specificity 75%; and 0.76 (0.61 to 0.87]; sensitivity 71%, specificity 71%, respectively). However, only PPVVM showed a significant AUC-difference from that of central venous pressure (P = 0.008) and correlated with the change of cardiac index induced by volume expansion (r = 0.6, P < 0.001). CONCLUSION: Augmented PPV using a Valsalva manoeuvre can be used as a clinically reliable predictor of fluid responsiveness under open-chest condition. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02457572.

ISMICS Consensus Conference and Statements of Randomized Controlled Trials of Off-Pump Versus Conventional Coronary Artery Bypass Surgery.

OBJECTIVE: At this consensus conference, we developed evidence-informed consensus statements and recommendations on the practice of off-pump coronary artery bypass graft (OPCAB) by systematically reviewing and performing meta-analysis of the randomized controlled trials (RCTs) comparing OPCAB and conventional coronary artery bypass (CCAB). METHODS: All RCTs of OPCAB versus CCAB through April 2013 were screened, and 102 relevant RCTs (19,101 patients) were included in a systematic review and meta-analysis (15 RCTs of 9551 high-risk patients; and 87 RCTs of 9550 low-risk patients) in accordance with the Cochrane Collaboration and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology. Consensus statements for the risks and benefits of OPCAB surgery in mortality, morbidity, and resource use were developed based on best available evidence. RESULTS: Compared to CCAB, it is reasonable to perform OPCAB to reduce risks of stroke [class IIa, level of evidence (LOE) A], renal dysfunction/failure (class IIa, LOE A), blood transfusion (class I, LOE A), respiratory failure (class I, LOE A), atrial fibrillation (class I, LOE A), wound infection (class I, LOE A), ventilation time, and ICU and hospital length of stay (class I, LOE A). However, OPCAB may be associated with a reduced number of grafts performed (class I, LOE A) and with diminished graft patency (class IIa, LOE A, with increased coronary reintervention at 1 year and beyond (class IIa, LOE A), as well as increased mortality at a median follow-up of 5 years (class IIb, LOE A). CONCLUSIONS: OPCAB compared with CCAB may improve outcomes in the short-term (stroke, renal dysfunction, blood transfusion, respiratory failure, atrial fibrillation, wound infection, ventilation time, and length of stay). However, over the longer-term, OPCAB may be associated with reduced graft patency, and increased risk of cardiac re-intervention and death.

Presentation of a quality management program in off-pump coronary bypass surgery.

OBJECTIVE: To increase the number of off-pump coronary procedures at our institution, a new surgical team was formed. The first 3 years of "learning period" were accompanied by a quality management program aimed to control and adjust the surgical process and to ensure the safety and quality of the procedure. METHODS: All patients were operated on by the same surgeon between January 2004 and December 2006; all procedures were performed under the following quality management protocol. First, a flow chart regulated surgical and anesthetic details. Second, an online file, named "disturbance file," was used to report work flow interruption, disturbance, and intraoperative events, that is, myocardial ischemia, hypotension, conversion to cardiopulmonary bypass, and any violation of the protocol. Each event was coded with 1 point and added to a score (the higher the score is, the greater the disturbance). Outcome parameters known as major events-major cardiac and cerebral events: mortality within 30 days/myocardial infarction confirmed by electrocardiogram or significantly high levels of total creatine kinase-myocardial muscle creatine kinase/reintervention within 30 days/stroke--and new-onset dialysis were also measured. Success was defined as freedom from any of those events and depicted in a cumulative sum control (CUSUM) chart. Outcome data and CUSUM were correlated with the intraoperative Disturbance Index. RESULTS: In total, 490 off-pump coronary bypass operations were performed by the named surgeon during the study period. The 30-day mortality was reduced from 4.0% to 1.9%. Disturbance Index score of greater than 1 declined from 41.6% to 23.3%. All major cardiac and cerebral events declined. The CUSUM chart showed two critical periods during the learning period, which made an adjustment of the protocol necessary. CONCLUSIONS: Quality management control is efficient in improving the postoperative results of a surgical procedure. A learning period is of cardinal importance for any new team wishing to engage in a novel surgical technique.

Improved short-term outcomes with off-pump reoperative coronary artery bypass grafting.

OBJECTIVE: Reoperative coronary surgery patients are usually sicker and older, and the procedure is more technically demanding. Comparisons between coronary surgery with (coronary artery bypass [CAB] surgery on cardiopulmonary bypass [CPB]) and without (off-pump CAB [OPCAB]) the pump have been conducted; however, few studies showed results in reoperative cases. We investigate the potential superiority of one technique over the other in redo coronary surgeries. METHODS: Our institutional Society of Thoracic Surgery database was used to gather the data for 266 isolated reoperative coronary artery surgeries from January 2004 to July 2011. These were divided into the CAB surgery in CPB group (n = 204) and the OPCAB group (n = 62). RESULTS: Baseline characteristics of the two groups were similar, except for a significantly higher prevalence of cerebrovascular disease among the off-pump group (P = 0.01). There was also a trend toward fewer vessels bypassed among the same group (P = 0.07). Risk adjustment was done using multivariable analyses for detection of independent effects. The use of CPB was an independent predictor of increased rates of postoperative events (odds ratio, 3.9; P = 0.004) and atrial fibrillation (odds ratio, 5.9; P < 0.005) and longer intensive care unit (0.006) and hospital stay (0.004). CONCLUSIONS: Redo OPCAB seems to offer favorable short-term outcomes compared with redo CAB. Our results suggest a reduced rate of overall postoperative events, decreased new postoperative atrial fibrillation, reduced hours stayed in the intensive care unit, and fewer days stayed from surgery to discharge. This was not associated with an increase in morbidity and mortality. A randomized study with a larger number of patients and with a longer follow-up is needed.

Surgical proficiency and quality indicators in off-pump coronary artery bypass.

BACKGROUND: Off-pump coronary artery bypass (OPCAB) was developed to decrease postoperative mortality and morbidity. Surgeon experience influences outcome. The required levels of surgical proficiency and maturation of technical skills are uncertain. We sought to assess the surgical proficiency in OPCAB and to identify the required levels of technical maturation. METHODS: We included 1,055 consecutive patients undergoing OPCAB. Patients were divided by 100s into 11 groups by timing of operation. Surgical proficiency was evaluated by 2 quality indicators: revascularization index and conversion rate in nonemergency cases. RESULTS: Mode of intervention was elective in 768 patients, urgent in 185 patients, and emergent in 102 patients (9.7%). The in-hospital mortality rate was 5.1% and ranged from 3% (group 3) to 9% (group 11). The percentage of triple-vessel disease and the mean number of diseased vessels increased over time. The mean number of distal anastomoses increased over time, from 2.64 ± 0.82 in group 1 to 4.13 ± 0.98 in group 11. It reached a plateau of 4.0 at group 7 (cases 600-700). The revascularization index also increased over time, from 1.01 ± 0.20 in group 1 to 1.41 ± 0.28 in group 11. It reached a plateau of 1.4 at group 7 (cases 600-700). The conversion rate in nonemergent cases decreased rapidly as the volume of OPCAB increased, and it reached a baseline of 5% at group 3 (cases 200-300). CONCLUSIONS: Surgical proficiency at performing OPCAB could be evaluated with 2 quality indicators: revascularization index of 1.4 or more and conversion rate in nonemergent cases of 5% or less. The required case number for technical maturation was 200 to 300 for conversion and 600 to 700 for complete revascularization.

Surgical treatment of left main disease and severe carotid stenosis: does the off-pump technique provide a better outcome?

OBJECTIVES: Left main disease (LMD), combined with carotid artery stenosis (CAS), constitutes a high-risk patient population. Priority is often given to coronary revascularization, due to the severity of the angina. However, the choice of revascularization strategy [off-pump coronary artery bypass (OPCAB) vs coronary artery bypass grafting (CABG)] remains elusive. METHODS: A total of 1340 patients with LMD were non-randomly assigned to either on-pump (CABG group, n = 680) or off-pump (OPCAB group, n = 634) revascularization between 1 January 2006 and 21 September 2010. Multivariable regression was used to determine the risk-adjusted impact of a revascularization strategy on a composite in-hospital outcome (MACCE), and proportional hazards regression was used to define the variables affecting long-term survival. RESULTS: Significant CAS was found in 130 patients: 84 (13.1%) patients underwent OPCAB, while 46 patients (6.8%) underwent CABG (P < 0.05). Patients with a history of stroke/transient ischaemic attack were also more likely to receive OPCAB (7.1 vs 4.7%; P = 0.08). OPCAB patients were older, in a higher New York Heart Association (NYHA) class, with a lower LVEF and higher EuroSCORE. A calcified aorta was found in 79 patients [OPCAB-CABG: 49 (7.73%) vs 30 (4.41%); P = 0.016] and resulted in a less complex revascularization (OPCAB-CABG: 2.3 ± 0.71 vs 3.19 ± 0.82; P < 0.05), and 30-day mortality was insignificantly higher in the CABG (2.7 vs 2.8%) as well as MACCE (11.2 vs 12.2%; P = NS). This trend reversed when late mortality was evaluated; however, it did not reach significance at 60 months. Preoperative renal impairment requiring dialysis was found to be a technique-independent predictor of MACCE. The number of arterial conduits also influenced MACCE. CONCLUSIONS: Off-pump coronary revascularization may offer risk reduction of neurological complications in patients with a significant carotid artery disease and a history of previous stroke, but a larger study population is needed to support this thesis. The growing discrepancy in long-term survival should draw attention to a more complete revascularization in OPCAB patients.

NICE guidance for off-pump CABG: keep the pump primed.

Because of a desire to reduce the morbidity of a well-established and effective procedure for coronary artery disease, up to 30% of coronary bypass operations are being performed without the use of a heart-lung pump. Concerns remain about the quality of the coronary anastomoses and the completeness of revascularisation. Randomised trials have not disclosed the significant reduction in morbidity or mortality that the early enthusiasts had hoped for. Yet a number of non-randomised studies have shown clinical benefit with the avoidance of an extracorporeal circulation, but these studies have been criticised for potential bias in patient selection and management. Most surgeons have not yet adopted this technique and are waiting for more evidence.

Comparison of uncalibrated arterial pressure waveform analysis with continuous thermodilution cardiac output measurements in patients undergoing elective off-pump coronary artery bypass surgery.

OBJECTIVE: Monitoring of cardiac output is required during anesthesia for off-pump coronary artery bypass (OPCAB) surgery. Recently, FloTrac, a new device for arterial pressure waveform analysis for cardiac output (APCO) monitoring without external calibration, was developed. The authors have compared APCO with STAT-mode continuous cardiac output (SCCO) in patients undergoing OPCAB surgery. DESIGN: A clinical study. SETTING: A university hospital (single institution). PARTICIPANTS: Thirty consecutive patients undergoing elective OPCAB surgery. INTERVENTIONS: Arterial pressure measurement with FloTrac, pulmonary arterial catheter insertion. MEASUREMENTS AND MAIN RESULTS: APCO and SCCO measurements were recorded after pulmonary artery catheter insertion (T1), after sternotomy (T2), after heart positioning for left anterior descending artery anastomosis (T3, T4), after heart positioning for obtuse marginal artery anastomosis (T5, T6), after heart positioning for posterior descending artery anastomosis (T7, T8), and after sternal closure (T9). APCO and SCCO were compared using the Bland-Altman method and the percentage error by Critchley's criteria. SCCO and APCO ranged from 2.1 to 6.9 L/min and 1.2 to 7.4 L/min, respectively, and showed low correlation (r = 0.29). The overall bias by the Bland-Altman method between SCCO and APCO was -0.23 L/min, with a precision of -1.4 to 0.9 L/min, and the overall limits of agreement were -2.5 to 2.0 L/min. The overall mean CO was 4.0 ± 0.95 L/min. The overall percentage error between SCCO and APCO measurements was 57%. CONCLUSIONS: Uncalibrated APCO values do not agree with thermodilution SCCO and significantly overestimated the SCCO in patients undergoing OPCAB surgery. Further evaluation is required to verify the clinical acceptance of FloTrac APCO in OPCAB surgery.

Medium-term results of systematic off-pump coronary surgery performed by trainee surgeons.

OBJECTIVE: Our unit has used off-pump coronary artery bypass (OPCAB) surgery since 1998, and has consequently developed teaching methods for surgical trainees. This study aimed to compare the medium-term results of OPCAB performed by experts or supervised trainees. METHODS: We retrospectively analysed the data relating to 1333 OPCAB operations performed between January 1998 and January 2006 (mean patient age: 65.3 + or - 13; M/F ratio: 2.9), and compared the medium-term outcomes of the 977 (73.3%) carried out by three expert surgeons (group A) with the remaining 356 (26.7%) carried out by four supervised trainees (group B). RESULTS: There were no preoperative differences in patient age, gender, angina class, operative priority, extent of coronary artery disease, the presence of a recent myocardial infarction or left main stenosis or European System for Cardiac Operative Risk Evaluation (EuroSCORE) between the two groups. Thirty-day mortality was 1% in group A and 0.6% in group B (p=0.43), and 4-year actuarial survival, respectively, 97.4 + or - 1.1% and 94.3 + or - 4.1% (p=0.41); the freedom from new re-vascularisation rates in the two groups were, respectively, 96 + or - 0.7% and 95.3 + or - 1.4% (p=0.3). CONCLUSIONS: The results of this study reflect our unit's long experience of OPCAB surgery and that its successful re-engineering towards the systematic use of OPCAB was feasible. They also show that, in this context, teaching OPCAB surgery is safe in a non-selected cohort of patients, and that the medium-term outcomes of the patients operated on by trainee or expert surgeons are similar.

Cardiac output monitoring: comparison of a new arterial pressure waveform analysis to the bolus thermodilution technique in patients undergoing off-pump coronary artery bypass surgery.

OBJECTIVE: To analyze the clinical agreement between the conventional intermittent bolus thermodilution (TD) technique and a new arterial pressure waveform analysis (APCO) technique (FloTrac; Edward Lifesciences, Irvine, CA) for cardiac output (CO) estimation. DESIGN: Prospective observational clinical study. SETTING: Cardiac surgery operating room of a tertiary care cardiac center. PARTICIPANTS: Twelve patients undergoing elective off-pump coronary artery bypass (OPCAB) surgery. MEASUREMENTS AND MAIN RESULTS: CO was determined by 2 different methods: TD and APCO at 8 time points (preinduction, postinduction, poststernotomy, left internal mammary artery to left anterior descending artery anastomosis, left [obtuse marginal/diagonal] anastomosis, right [right coronary/posterior descending coronary artery] anastomosis, postprotamine administration, and poststernal closure) in 12 patients undergoing elective OPCAB surgery. The mean bias and limits of agreement (2 standard deviations) expressed in liters per minute at respective points of measurement were -0.54 +/- 1.12, -0.37 +/- 1.0, -0.42 +/- 1.50, -0.25 +/- 1.18, -0.31 + 1.28, +/-0.41 +/- 1.0, 0.06 +/- 1.50, and 0.09 +/- 1.40. CONCLUSION: Good agreement was found between the CO values obtained by the APCO and TD techniques throughout the intraoperative period including the period of coronary artery graft surgery.

Immediate results of right internal thoracic artery and radial artery as the second arterial graft in myocardial revascularization.

OBJECTIVE: We sought to compare early clinical outcomes in patients receiving a right internal thoracic artery or a radial artery as the second arterial graft in myocardial revascularization. METHODS: We retrospectively studied 58 consecutive patients who underwent coronary artery bypass surgery and received both a left internal thoracic artery graft and either a right internal thoracic artery (n=20) or a radial artery graft (n=38), between January 2004 and March 2006. Hospital mortality, pleural drainage, operative time and postoperative complications were analyzed. RESULTS: There were no significant preoperative differences between groups. There was only one (1.7%) in-hospital death which occurred in the Radial Group. Operative times was significantly higher in the Right Internal Thoracic Group (p-value = 0.0018), but were not associated with increased Intensive Care Unit stays, mechanical ventilation or other postoperative complications. We were able to perform significantly more distal anastomosis using the radial artery than the right internal thoracic artery (1.57 versus 1.05: p-value =0.003). CONCLUSION: In our group of patients, the use of a right internal thoracic artery as a second arterial graft was associated with a prolonged operative time, but had no interference with the immediate clinical outcomes.

OPCAB in patients on hemodialysis.

OBJECTIVE: To analyze the hospital outcomes of patients, with chronic renal insufficiency in the hemodialysis, submitted to OPCAB. METHOD: Fifty-one patients with chronic renal insufficiency were submitted to OPCAB. Hemodialysis was performed on the day before and the day after the operation. Myocardial revascularization was performed using LIMA's suture and suction stabilization. RESULTS: Fifty-one patients, with an average of 61.28+/-11.09 years, were analyzed. Thirty patients (58.8%) were female. The predominant functional class was IV in 21 (41.1%) of the patients. The left ventricle ejection fraction was dire in 21 (41.1%) patients. The mean EUROSCORE of this series was 7.65+/-3.83 and the mean number of distal anastomosis was 3.1+/-0.78 per patient. The average time of mechanical ventilation was 3.78+/-4.35 hours and the mean ICU stay was 41.9+/-13.8 hours, while the average hospitalization was 6.5+/-1.31 days. In respect to complications, nine (17.6%) of the patients developed atrial fibrilation, and one (1.9%) patient presented with a case of ischemic stroke but had a good recovery during hospitalization. There were no deaths in this series. CONCLUSION: Chronic renal patients submitted to hemodialysis were always a high risk population for myocardial revascularization. In this series, the absence of extracorporeal circulation appeared to be safe and efficient in this special subgroup of patients. The operations were performed with low indices of complications, absence of deaths and relatively low stays in the ICU and in hospital.

Off-pump coronary artery bypass grafting for acute myocardial infarction.

BACKGROUND: The aim of this study was to evaluate the surgical results of off-pump coronary artery bypass grafting (OPCAB) for patients with acute myocardial infarction (AMI) within 14 days of the infarction. METHODS AND RESULTS: From April 2000 to January 2005 among 841 patients who underwent OPCAB, 43 consecutive patients (5.1%) were examined. Mean age at operation was 69.5 years and mean time from the onset of AMI to surgery was 4.6 days. Seventeen patients (39.5%) had left main trunk disease. Three patients (7.0%) underwent OPCAB following unsuccessful percutaneous coronary intervention, and 1 patient (2.3%) underwent redo procedure 9 years after previous coronary artery bypass grafting (CABG). Six patients (14%) were admitted in cardiogenic shock. Intraaortic balloon pumping was inserted preoperatively in 20 patients (46.5%). The average maximum creatine kinase-myocardial band was 139+/-181 (U/L). The mean number of grafts was 3.2 and the rate of complete revascularization was 91%. Two of six patients with preoperative cardiogenic shock were converted to on-pump beating CABG due to ventricular arrythmia. The early graft patency rate was 98%. All patients survived except 2 with preoperative cardiogenic shock. CONCLUSIONS: OPCAB can be performed after AMI as a relatively low-risk procedure with an acceptable mortality rate, even within 14 days of the infarction.