Conversion during off-pump coronary artery bypass graft surgery: A case–control study

Abstract

Objectives: Off pump coronary artery bypass (OPCAB) surgery is carried out as an alternative to conventional coronary artery bypass grafting using cardiopulmonary bypass (CPB). At times ‘conversion’ to CPB may be required to bail out a situation resulting from acute decompensation of the heart. It is reported that such conversion carries significant mortality risk. Since we conduct coronary revascularization by OPCAB technique as the preferred technique, we conducted this study with an aim to identify the markers of adverse outcome during conversion in Indian patients. Design: Case control retrospective study. Setting: Tertiary referral center. Participants: We conducted three thousand two hundred OPAB surgeries in the period between 2013 to16. Ninety patients (3.1%) required conversion to complete the revascularization (Con version group). Twice the number of patients who underwent OPCAB surgery without conver sion were chosen as controls (Control group). Intervention: OPCAB surgery Results: Mortality in the conversion group was 5.56% in contrast to 0.06% in the controls ( P = 0.01). The conversion group had higher left ventricular end diastolic pressure, incidence of endarterectomy, and intra-aortic balloon counter pulsation requirement. Female gender was also predictive of conversion. The total chest drain, duration of ventilation, ICU stay and hospital stay were also higher in the conversion group. Conversion was associated with 9.47 times the odds for mortality. Conclusion: Conversion during OPCAB is associated with significantly increased mortality. Female gender, increased left ventricular end diastolic pressure and preoperative requirement of Intra-aortic balloon are markers of increased risk of mortality when converted.

Peripheral extracorporeal membrane oxygenation support expands the application of robot-assisted coronary artery bypass

“…It is well established that conversion to sternotomy in off-pump cases is associated with a significantly higher morbidity and mortality. 11,12 By establishing RCAB with ECMO as a safe revascularization strategy, we also hope to redefine the indications for minimally invasive CAB. Historically, the ideal candidates for such approaches were younger, healthier patients with preserved ventricular function and primarily single-vessel disease.…”

Preoperative right ventricular dysfunction requires high vasoactive and inotropic support during off-pump coronary artery bypass grafting

“…Fifth, the patient's physique and cardiac size were not taken into account in TAPSE. Sixth, we decided the variables for multiple regression analysis based on previous reports about emergency conversion or hemodynamics of OPCAB [ 5 – 16 ]. It is possible that unknown confounding factors caused bias.…”

“…VIS was calculated as (dopamine dose + dobutamine dose) (mcg/kg/min) + 10 times milrinone dose (mcg/kg/min) + 100 times (epinephrine dose + norepinephrine dose) (mcg/kg/min) + 10,000 times vasopressin dose (unit/kg/min) [ 19 , 20 ] and was used to evaluate intraoperative hemodynamics. Age [ 6 ], sex [ 16 ], urgent surgery [ 5 , 6 , 8 ], TVD [ 6 , 8 , 13 ], LMT disease [ 7 , 8 , 12 , 13 ] and CHF [ 6 , 8 , 11 , 13 , 14 ] were considered to be essential or definitive variables associated with VIS without multicollinearity among the variables and were included in multivariate regression analysis. We defined the patients who required hospitalization and treatment by a cardiologist before surgery as CHF.…”

“…Urgent/emergent was defined based on Japan Cardiovascular Surgery Database. Other potential variables including TAPSE, TR, LVEF [ 6 , 14 ], MR [ 12 , 15 ], early diastolic trans-mitral blood flow velocity divided by early diastolic lateral mitral annulus tissue velocity (E/Ea) (There was no record of LVEDP [ 16 ]. ), LVH [ 5 ], Canadian Cardiovascular Society functional classification (CCS classification) [ 5 ], preoperative acute myocardial infarction (AMI) [ 8 , 14 ], cerebrovascular disease (CVD) [ 5 ], diabetes mellitus (DM) [ 5 ] and anesthesiologists’ or surgeons’ experience [ 9 , 11 ] were used in multivariate regression analysis if their P values were less than 0.1 in simple regression analysis.…”

“…Previous studies have shown that urgent surgery [ 5 , 6 , 8 ], triple vessel disease (TVD) [ 6 , 8 , 13 ], left main coronary artery (LMT) disease [ 7 , 8 , 12 , 13 ], congestive heart failure (CHF) [ 6 , 8 , 11 , 13 , 14 ] and previous CABG [ 5 , 8 , 11 ] are preoperative risk factors of emergency conversion. In addition, left ventricular dysfunctions including low left ventricular ejection fraction (LVEF) [ 6 , 14 ], mitral regurgitation (MR) [ 12 , 15 ], high left ventricular end diastolic pressure (LVEDP) [ 16 ] and left ventricular hypertrophy (LVH) [ 5 ] have been shown to be factors causing hemodynamic instability that can result in the need for emergency conversion.…”