Acute clinical and financial outcomes of on- versus off-pump coronary artery bypass grafting in octogenarians.

BACKGROUND: Coronary artery bypass surgery in octogenarians is associated with increased postoperative morbidity. Off-pump coronary artery bypass surgery eliminates potential complications of cardiopulmonary bypass, but its use remains controversial. This study aimed to evaluate the clinical and financial impact of off-pump coronary artery bypass surgery compared to conventional coronary artery bypass surgery among this high-risk population. METHODS: Patients ≥80 years undergoing first-time, isolated, elective coronary artery bypass surgery were identified using the 2010-2019 Nationwide Readmissions Database. Patients were grouped into off-pump or conventional coronary artery bypass surgery cohorts. Multivariable models were developed to assess the independent associations between off-pump coronary artery bypass surgery and key outcomes. RESULTS: Of ∼56,158 patients, 13,940 (24.8%) underwent off-pump coronary artery bypass surgery. On average, the off-pump cohort was more likely to undergo single-vessel bypass (37.3 vs 19.7%, P < .001). After adjustment, undergoing off-pump coronary artery bypass surgery was associated with similar odds of in-hospital mortality (adjusted odds ratio 0.90, 95% confidence interval 0.73-1.12) relative to conventional bypass. Additionally, the off-pump and conventional coronary artery bypass surgery groups were comparable in odds of postoperative stroke (adjusted odds ratio 1.03, 95% confidence interval 0.78-1.35), cardiac arrest (adjusted odds ratio 0.99, 95% confidence interval 0.71-1.37), ventricular fibrillation (adjusted odds ratio 0.89, 95% confidence interval 0.60-1.31), tamponade (adjusted odds ratio 1.21, 95% confidence interval 0.74-1.97), and cardiogenic shock (adjusted odds ratio 0.94, 95% confidence interval 0.75-1.17). However, the off-pump coronary artery bypass surgery cohort was linked with an increased likelihood of ventricular tachycardia (adjusted odds ratio 1.23, 95% confidence interval 1.01-1.49) and myocardial infarction (adjusted odds ratio 1.34, 95% confidence interval 1.16-1.55). Furthermore, those undergoing off-pump coronary artery bypass surgery demonstrated reduced odds of non-home discharge (adjusted odds ratio 0.91, 95% confidence interval 0.83-0.99) and a decrement in hospitalization expenditures ($-1,290, 95% confidence interval -$2,370 to $200). CONCLUSION: Off-pump coronary artery bypass surgery was linked with increased odds of ventricular tachycardia and myocardial infarction, but no difference in mortality. Our findings point to the safety of conventional coronary artery bypass surgery in octogenarians. Yet, future work is needed to consider long-term outcomes in this complex surgical cohort.

The effects of high-sensitivity C-reactive protein on the clinical outcomes in obstructive sleep apnea patients undergoing off-pump coronary artery bypass grafting.

PURPOSE: To investigate the relationship between obstructive sleep apnea (OSA) severity and high-sensitivity C-reactive protein (Hs-CRP), and their respective impact on the clinical outcomes in patients undergoing off-pump cardiac artery bypass grafting (OPCABG). METHODS: We enrolled consecutive eligible patients listed for elective OPCABG who underwent cardiorespiratory polygraphy before surgery between January 2019 and December 2019 in this prospective observational single-center study. Baseline, intraoperative, and postoperative clinical data were compared between absent-mild and moderate-severe OSA groups. Regression analysis investigated the relationship between Hs-CRP level and severity of OSA, and further assessed the factors influencing postoperative atrial fibrillation, duration of hospitalization, and hospital cost. RESULTS: Patients with moderate-severe OSA accounted for 42.3% (52/123) of the cohort. Partial pressure of carbon dioxide (PCO2), Hs-CRP, apnea hypopnea index (AHI), mean apnea time, maximum apnea time, and oxygen desaturation index ODI ≥ 3% were significantly higher in the moderate-severe OSA group than in the absent-mild OSA group. Left ventricle ejection fraction (LVEF), lowest arterial oxygen saturation (SaO2), and mean SaO2 were significantly lower in the moderate-severe OSA group. Moderate-severe OSA was associated with elevated Hs-CRP level (OR = 2.356, 95% CI 1.101-5.041, P = 0.027). Hs-CRP was an independent risk factor for post-CABG atrial fibrillation (POAF) (OR = 1.212, P = 0.01). Hs-CRP level independently correlated with duration of hospitalization (B = 0.456, P = 0.001) and hospital cost (B = 1.111, P = 0.044). CONCLUSION: Hs-CRP level was closely related to OSA severity and have potential utility in predicting POAF, duration of hospitalization, and hospital costs in patients undergoing OPCABG.

Blood flow assessment by transit time flow measurement and its prognostic impact in coronary bypass surgery.

BACKGROUND: The competitive coronary flow is influenced by the severity of the stenosis and may affect graft patency. Transit time flow measurement (TTFM) enables intraoperative graft evaluation and cardiac magnetic resonance (MRI) allows for graft evaluation during follow-up. METHODS: Competitive flow and target vessel diameters were determined in 35 patients undergoing off-pump coronary bypass graft surgery (CABG) and correlated to TTFM. Cardiac function, ischemia, and graft flow were evaluated using cardiac MRI during the follow-up period to determine the impact of above-mentioned parameters on graft patency. RESULTS: Competitive flow led to reduced mean graft flow (MGF) and increased pulsatility index (PI) in arterial grafts. This effect to was not observed in veins. Smaller target coronary arteries (<1.5 mm) were associated with reduced MGF, more pronounced in veins, which presented increased PI and shortened diastolic flow fraction (DF). No death and no re-hospitalization for acute coronary syndrome occurred. Borderline values of TTFM (mean MGF 13±4 mL/min; PI 3.8±1) in left internal mammary artery (LIMA) were mainly observed due to increased native anterior descending artery (LAD) flow. These LAD's collateralized occluded right coronaries (RCA). The corresponding LIMA to LAD grafts showed a bypass flow increase at cardiac MRI follow-up. Two graft occlusions occurred: one in LIMA-to-LAD bypass with borderline TTFM, which did not collateralize the RCA and one in a vein graft with borderline TTFM bypassed on a narrow vascular target. CONCLUSIONS: Competitive flow has an impact on arteries contrary to veins. Veins are at risk for occlusion when grafted to smaller targets. Borderline LIMA flow should be considered as potentially dangerous, if satisfactory explanations are missing, e.g. in the absence of a large coronary target without flow competition.

Costs Five Years After Off-Pump or On-Pump Coronary Artery Bypass Surgery.

BACKGROUND: Coronary artery bypass grafting (CABG) is a common surgical treatment for ischemic heart disease. Little is known about the long-term costs of conducting the surgery on-pump or off-pump. METHODS: As part of the Randomized On/Off Bypass follow-up study, we followed 2,203 participants randomized to on-pump (n = 1,099) and off-pump (n = 1,104) CABG for 5 years using Department of Veterans Affairs and Medicare administrative data. We examined annual costs through 5 years, standardized to 2016 dollars, using multivariate regression models, controlling for site and baseline patient factors. RESULTS: In the first year, including the CABG surgery, annual average costs were $66,599 (SE, $1,946) for the on-pump group and $70,552 (SE, $1,954) for the off-pump group. In years 2 to 5, average costs ranged from $15,000 to $20,000 per year. There was no significant difference between on-pump and off-pump across the 5 years. We explored differences among high-risk subgroups (diabetes, chronic obstructive pulmonary disease, peripheral vascular disease, cerebrovascular disease, renal dysfunction, ejection fraction < 35%, over age 70 years), and found no treatment assignment by time interactions, except for a nonsignificant trend in patients with diabetes. CONCLUSIONS: At 5 years, the average costs of off-pump and on-pump CABG patients did not statistically differ. Costs do not favor one approach and the decision should be based on clinical risks, especially in subgroups. Future research is warranted to examine post-CABG costs and outcomes for diabetic patients over time.

[Flowmetric assessment of coronary bypass grafts in the conditions of artificial circulation and on the beating heart].

Advantages and shortcomings of aortocoronary bypass grafting on the beating heart and in the conditions of artificial circulation (AC) have long been discussed. The data on patency of bypass grafts in the remote period are indicative of comparable results of operations with and without AC or advantages of using AC. In order to determine benefits of each method it is necessary to reveal intraoperative predictors of bypass grafts occlusion in the remote period. We analyzed the results of ultrasound flowmetry of the blood flow through the left internal thoracic artery during bypass grafting of the anterior descending artery with the use of AC and on the beating heart. A retrospective study included a total of 352 patients subdivided into 2 groups: Group One was composed of 120 patients undergoing surgery in the conditions of AC and Group Two comprised 232 patients subjected to similar operations on the beating heart. Blood flow was measured with the help of flowmeter VeryQ MediStim® after termination of AC and inactivation of heparin by protamine, with systolic pressure of 100-110 mm Hg. There were no statistically significant differences between the groups by the diameter and degree of stenosis of the anterior descending artery, diameter of the left internal thoracic artery. The mean volumetric blood flow velocity (Qmean) along the shunts in Group One was higher (p=0.01). No statistically significant differences by the pulsatility index (PI) between the groups were revealed (p=0.2). A conclusion was drawn that coronary bypass grafting of the anterior descending artery by the left internal thoracic artery in the conditions of artificial circulation made it possible to achieve higher volumetric velocity of blood flow through the conduit as compared with operations on the beating heart, with similar resistance index. The immediate results of the operations with the use of the both techniques did not differ.

Assessment of feasibility and efficacy of Class IV laser therapy for postoperative pain relief in off-pump coronary artery bypass surgery patients: A pilot study.

BACKGROUND: Laser therapy, for its established analgesic properties with minimal side effects, has been used for the treatment of chronic pain. However, it has not been used for the treatment of acute postoperative pain. This pilot study was designed to assess the feasibility and efficacy of Class IV laser on postoperative pain relief following off-pump coronary artery bypass graft (OPCABG) surgery, as a component of multimodal analgesia (MMA) technique. METHODS: This open observational prospective study comprised of 100 adult patients (84 male, 16 female) who underwent OPCABG through sternotomy. For postoperative analgesia, they were subjected to laser therapy subjected to laser therapy in addition to the standard institutional pain management protocol comprising of IV infusion/bolus of tramadol and paracetamol and fentanyl bolus as rescue analgesic. Pain intensity was measured by Verbal Rating Scale (VRS). The laser therapy was scheduled as once a day regime for three consecutive postoperative days (PODs) starting on POD 1, 30 min following tracheal extubation. The subsequent laser applications were also scheduled at the same time of the day as on day 1 if VRS was ≥5. 10 W Class IV laser was applied over 150 cm² sternal wound area for 150 s. VRS was used to assess pain severity and was recorded for statistical analysis using Friedman Test. RESULTS: The mean (standard deviation [SD]) VRS of all the 100 patients just before application of the first dose of laser was 7.31 (0.94) while on MMT; the same fell to 4.0 (1.279) and 3.40 (2.697) at 1 h and 24 h respectively following first dose of laser. The change of VRS over first 24 h among all the 100 patients was statistically significant (P = 0.000). Laser was re-applied in 40 patients whose VRS was ≥5 (mean [SD] - 6.38 [0.868]) at 24th h. After receiving the 2nd dose of laser the VRS scores fell significantly (P = 0.000) and became 0 at 54th h. No patients required 3rd dose of the laser. No patient required rescue analgesic while on laser therapy. CONCLUSION: Class IV laser can be an effective technique for postoperative analgesia following OPCABG surgery through sternotomy when included as a component of MMA technique.

Short-term clinical outcomes after hybrid coronary revascularization versus off-pump coronary artery bypass for the treatment of multivessel or left main coronary artery disease: a meta-analysis.

BACKGROUND: Hybrid coronary revascularization (HCR) and off-pump coronary artery bypass grafting (OPCABG) are both feasible, less invasive techniques for coronary revascularization. Although both techniques utilize the left internal mammary artery to left anterior descending artery graft, HCR uses drug-eluting stents instead of saphenous vein bypass. It remains unclear whether HCR is equal to, better or worse than OPCABG. METHODS AND RESULTS: A meta-analysis was carried out using a random-effects model. Seven observational studies were included. There was no significant difference either in in-hospital mortality [relative risk (RR) 0.57, 95% confidence interval (CI) 0.13-2.59, P=0.47] or in the MACCE rate (RR 0.63, 95% CI 0.24-1.64, P=0.34) between the HCR group and the OPCABG group. A significant difference was observed between the two groups in the length of hospitalization (RR 0.55, 95% CI 0.13-0.97, P=0.01), length of ICU stay (RR 0.45, 95% CI 0.10-0.80, P<0.05), intubation time (RR 0.48, 95% CI 0.13-0.84, P<0.01), need for red blood transfusion (RR 0.67, 95% CI 0.56-0.82, P<0.001), and total in-hospital costs (RR 0.90, 95% CI 0.39-1.42, P<0.01). CONCLUSION: Compared with OPCABG, HCR did not improve early survival but decreased the length of hospitalization, length of ICU stay, intubation time, and need for red blood transfusion, and increased total in-hospitalcosts.

Assessment of long-term cognitive impairment after off-pump coronary-artery bypass grafting and related risk factors.

OBJECTIVES: To assess cognitive impairment after off-pump coronary-artery bypass grafting, with a particular emphasis on long-term follow-up and related risk factors. DESIGN: Prospective study. SETTING: Virgen de la Victoria University Hospital, Málaga, Spain. PARTICIPANTS: Participants were 36 patients undergoing off-pump coronary-artery bypass grafting. MEASUREMENTS: Changes in the neuropsychological test battery administered from before to after surgery (1, 6, and 12 months). Postoperative cognitive impairment was defined by a significant decrease. RESULTS: A significantly multidomain (attention-executive functions, P < .01; immediate and delayed memory, P < .001; and verbal fluency, P < .05) postoperative cognitive impairment was shown, being maximum at 6 months (more than 50% of patients) and still presented at 12 months (more than 30% of patients), but partially recovered. Related risk factors as smoking (P < .01), diabetes mellitus (P < .01), peripheral arteriopathy (P < .01), obesity (P < .05), lower hematocrit (P < .01), and hemoglobin (P < .05) levels and diastolic blood pressure (P < .05) were identified as predictors of cognitive impairment. Better New York Heart Association class (P < .01) and less severity of angina (P < .01) were associated with partial postoperative recovering. CONCLUSION: A multidomain long-term postoperative cognitive impairment and a partial neurocognitive recovering were detected after off-pump coronary-artery bypass grafting and were associated with several nonspecific surgery factors. These findings may be useful when counseling patients before surgery and suggest the importance of long-term neurocognitive evaluation.

Impact of pump status and conduit choice in coronary artery bypass: A 15-year follow-up study in 1412 propensity-matched patients.

OBJECTIVE: Previous studies have demonstrated that bilateral internal mammary artery (BIMA) grafts lead to superior outcomes compared with single internal mammary artery grafts. This study examines whether cardiopulmonary bypass affects conduit-dependent outcomes of coronary artery bypass grafting (CABG) surgery. METHODS: From 1994 to 2013, a total of 6666 patients underwent isolated CABG surgery at our institution. Of these procedures, 3548 (53.2%) were performed off pump. A BIMA-saphenous vein graft (SVG) was used in 1544, and 5122 had left internal mammary artery-SVGs. These 2 conduit groups differed significantly in baseline characteristics. Propensity matching based on 22 preoperative variables and using a nearest-neighbor matching algorithm was used to make balanced cohorts, resulting in 2 groups of 1006. To account for the influence of pump status on conduit selection, a second propensity score was developed for pump use. These cases were matched to create 4 patient cohorts of 353 patients each (a total of 1412), balanced for both conduit use and pump status. Late mortality was determined using the Social Security Death Index. RESULTS: No difference was found in survival between patients receiving BIMA-SVGs on or off pump (78.9% vs 79.1%). BIMA-SVGs outperformed the left internal mammary artery-SVGs regardless of whether the procedure was performed off pump (73.9%) or on pump (69.9%). CONCLUSIONS: This study demonstrates that the use of cardiopulmonary bypass does not significantly affect the long-term outcomes in these patients as long as full revascularization is achieved. In addition, these results are consistent with prior research showing that the use of BIMAs produces better outcomes than use of a single internal mammary artery when performing CABG.

[Evaluation of postoperative myocardial injury by heart-type fatty acid-binding protein in off-pump coronary artery bypass grafting surgery]. / Valoración del daño miocárdico mediante la medición de la heart-fatty acid-binding protein en cirugía de revascularización coronaria sin circulación extracorpórea. Estudio preliminar.

BACKGROUND AND GOAL OF STUDY: Postoperative myocardial infarction is a serious and frequent complication of cardiac surgery. Nonetheless, diagnosis in this context it is occasionally challenging. We sought to evaluate the kinetics and diagnostic accuracy of the new biomarker « heart-type fatty acid-binding protein ¼ (h-FABP) in the early detection of myocardial injury in patients undergoing off-pump coronary artery bypass grafting, compared with classical biomarkers. MATERIALS AND METHODS: A prospective study was conducted on 17 consecutive patients who underwent off-pump coronary artery bypass grafting during a 2 month period. Blood samples were drawn for measurement of myocardial ischemic injury biomarkers (h-FABP, troponin, creatine kinase [CK] and CK-MB), at baseline (T1), immediate post-coronary artery bypass grafting (T2), on ICU admission (T3), and after 4 (T4), 8 (T5), 24 (T6) and 48 h (T7). Perioperative ischemic complications, defined according to electrocardiographic, echocardiographic and hemodynamic criteria, were recorded. RESULTS: Earlier biomarkers peak plasma values occurred at T4 with troponin (2.9 ± 5.2 ng/mL), and at T5 with h-FABP (37.9 ± 55.5 ng/mL). Maximum values of CK and CK-MB occurred later, both in T6 (741 ± 779 and 37 ± 51 U/L, respectively). The optimized cut-off obtained for h-FABP was 19 ng/mL, providing a sensitivity and specificity of 77 and 75%, respectively, for diagnosis of perioperative ischemic injury, with an area under the ROC curve for h-FABP of 0.83 (95% CI 0.6-1.0) vs. 0.63 (95% CI 0.33-0.83) for troponin. This cut-off value for h-FABP is reached on average at T2 (mean value of h-FABP at T2: 18.9 ± 21.5 ng/mL). CONCLUSION: This is the first study evaluating the kinetics of h-FABP biomarker in perioperative off-pump coronary artery bypass grafting, and the cut-off value established could help to extend earlier detection of myocardial ischemia in this context.

The fate at mid-term follow-up of the on-pump vs. off-pump coronary artery bypass grafting surgery.

AIMS: To evaluate the fate of on-pump coronary artery bypass grafting (ON-pump CABG) vs. off-pump coronary artery bypass grafting (OP-CABG) surgery at mid-term follow-up. METHODS: From January 2008 to December 2010, 369 patients underwent surgical myocardial revascularization by means of OP-CABG techniques (n = 166) or with ON-pump CABG (n = 203). Data of the two groups of patients were retrospectively analyzed. RESULTS: As compared with OP-CABG, in the ON-pump CABG patients, mean value of Logistic EuroSCORE (8.1 ± 7.8% vs. 6.2 ± 5.9%, P = 0.04), more extended coronary disease (2.7 ± 0.5 vs. 2.5 ± 0.7 diseased vessels/patient, P < 0.001) consequently requiring greater number of grafts/patient (2.9 ± 0.9 vs. 2.3 ± 0.9, P < 0.0001), and emergency surgery (12 vs. 6%, P = 0.03) were more frequently observed. Operative mortality was 1.9% in ON-pump CABG vs. 1.2% in OP-CABG (P = 0.6) and incidence of stroke 2.46 vs. 1.81% (P = 0.7). The incidence of stroke was reduced at 1.2% when OP-CABG PAS-Port 'clamp-less' technique was used.Intraoperatively, costs per patient were higher for OP-CABG vs. ON-pump CABG (1.930,00 +1.050,00 €, if PAS-port system was included, vs. 1.060,00 € for ON-pump surgery). ICU stay (1.9 ± 1.0 days vs. 1.4 ± 0.7 days) and total postoperative in-hospital stay (5.3 ± 3.3 days vs. 5.5 ± 3.5 days) were similar in both groups.At 4 years, survival (91 ± 13% in the ON-pump CABG vs. 84 ± 19% in the OP-CABG), freedom from major adverse cardiac events (composite end-point of all-cause death, myocardial infarction, and repeat coronary revascularization of the target lesion) (82 ± 9% vs. 76 ± 14%), and major adverse cardiac and cerebrovascular events (80 ± 11% vs. 72 ± 16%) were not significantly different. Freedom from late cardiac death was slightly significant higher after ON-pump CABG (98 ± 4% vs. 90 ± 10%, P = 0.05). CONCLUSION: Mid-term freedom from composite end-points is similar after ON-pump CABG and OP-CABG. Freedom from cardiac death appears to be better after ON-pump CABG. OP-CABG needs for more expensive surgical technique. OP-CABG performed by an experienced surgical team using 'clamp-less' techniques can be an effective strategy in reducing postoperative stroke.

Worse long-term survival after off-pump than on-pump coronary artery bypass grafting.

OBJECTIVE: To determine whether off-pump coronary artery bypass grafting (CABG) is associated with worse long-term survival compared with on-pump CABG. We performed a meta-analysis of adjusted observational studies and randomized controlled trials. METHODS: MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched through March 2014. Eligible studies were randomized controlled trials and adjusted observational studies (in which appropriate statistical methods adjusting for confounders had been used) of off-pump versus on-pump CABG that had reported long-term (≥5-year) all-cause mortality as an outcome. RESULTS: Of 478 potentially relevant studies screened initially, 5 randomized trials and 17 observational studies, enrolling a total of 104,306 patients, were identified and included. A pooled analysis of all 22 studies demonstrated a statistically significant 7% increase in long-term all-cause mortality with off-pump relative to on-pump CABG (hazard ratio, 1.07; 95% confidence interval, 1.03-1.11; P=.0003). Although a pooled analysis of 5 randomized trials (1486 patients) demonstrated a statistically nonsignificant 14% increase in mortality with off-pump relative to on-pump CABG (hazard ratio, 1.14; 95% confidence interval, 0.84-1.56; P=.39), another pooled analysis of 17 observational studies (102,820 patients) demonstrated a statistically significant 7% increase in mortality with off-pump relative to on-pump CABG (hazard ratio, 1.07; 95% confidence interval, 1.03-1.11; P=.0004). CONCLUSIONS: A meta-analysis of 22 studies, enrolling a total of >100,000 patients, showed that off-pump CABG is likely associated with worse long-term (≥5-year) survival compared with on-pump CABG.

OPCAB surgery is cost-effective for elderly patients.

OBJECTIVE: To determine the cost-effective operative strategy for coronary artery bypass surgery in patients above 70 years. DESIGN: Randomized, controlled trial of 900 patients above 70 years of age subjected to coronary artery bypass surgery. Patients were randomized to either on-pump or off-pump coronary artery bypass surgery. Data on direct and indirect costs were prospectively collected. Preoperatively and six months postoperatively, quality of life was assessed using EuroQol-5D questionnaires. Perioperative in-hospital costs and costs of re-intervention were included. RESULTS: The Summary Score of EuroQol-5D increased in both groups between preoperatively and postoperatively. In the on-pump group, it increased from 0.75 (0.16) (mean (SD)) to 0.84 (0.17), while the increase in the off-pump group was from 0.75 (0.15) to 0.84 (0.18). The difference between the groups was 0.0016 QALY and not significantly different. The mean costs were 148.940 D.Kr (CI, 130.623 D.Kr-167.252 D.Kr) for an on-pump patient and 138.693 D.Kr (CI, 123.167 D.Kr-154.220 D.Kr) for an off-pump patient. The ICER base-case point estimate was 6,829,999 D.Kr/QALY. The cost-effectiveness acceptability curve showed 89% probability of off-pump being cost-effective at a threshold value of 269,400 D.Kr/QALY. CONCLUSIONS: Off-pump surgery tends to be more cost-effective than on-pump surgery. Long-term comparisons are warranted.

Outcomes of off-pump versus on-pump coronary artery bypass grafting: Impact of preoperative risk.

BACKGROUND: It is unknown whether purported benefits of off-pump coronary artery bypass grafting are patient-specific within the Society of Thoracic Surgeons National Cardiac Database or dependent on center volume or operating surgeon. METHODS: The Society of Thoracic Surgeons National Cardiac Database was queried for all patients undergoing nonemergency, isolated coronary artery bypass between January 1, 2005, and December 31, 2010, who had Predicted Risk of Mortality scores and participant/surgeon identifiers. Of these 876,081 patients ("all sites"), 210,469 underwent surgery at participant sites that had performed more than 300 off-pump and 300 on-pump coronary artery bypass operations during the 6-year study period ("high-volume sites"). Operative mortality, stroke, acute renal failure, mortality or morbidity, and prolonged postoperative length of stay were analyzed with conditional logistic models for all sites and for high-volume sites, stratified by participant center and surgeon, and adjusted for 30 variables that comprise the Society of Thoracic Surgeons coronary artery bypass grafting risk models. RESULTS: Off-pump coronary artery bypass was associated with a significant reduction in risk of death, stroke, acute renal failure, mortality or morbidity, and postoperative length of stay compared with on-pump coronary artery bypass after adjustment for 30 patient risk factors in the overall sample. This held true within high-volume centers. In the overall sample, there was a significant (P < .05) interaction between off-pump coronary artery bypass and Predicted Risk of Mortality for death, stroke, acute renal failure, and mortality or morbidity. CONCLUSIONS: Off-pump coronary artery bypass was associated with reduced adverse events compared with on-pump coronary artery bypass after adjustment for 30 patient risk factors and center and surgeon identity. Patients with higher Predicted Risk of Mortality scores had the largest apparent benefit.

Is there a surgeon or hospital volume-outcome relationship in off-pump coronary artery bypass surgery?

A best evidence topic was written according to a structured protocol. The question addressed was whether there is a surgeon or hospital volume-outcome relationship in patients undergoing off-pump coronary artery bypass surgery. A total of 281 papers were found using the reported searches, of which six represented the best evidence to answer the clinical question. The authors, date, journal, study type, population, main outcome measures and results are tabulated. The studies found analysed the outcomes of off-pump coronary artery bypass surgery in relation to surgeon or hospital volume and evaluated the presence of a volume-outcome relationship. Reported measures included mortality and major adverse cardiovascular and cerebrovascular events. The methodological quality and strength of each study for exploring volume-outcome relationships were quantitatively assessed using a predefined scoring system. Three studies analysed surgeon volume and three studies analysed hospital volume. The two largest and most recent studies presented a significant volume-outcome relationship in mortality and postoperative complications. Perhaps owing to the smaller sample size, this significant relationship in mortality was not observed in the four smaller studies; however, one of these studies demonstrated a significantly positive relationship for postoperative complications and another study demonstrated a similar significant relationship for the number of grafts and the degree of completeness of revascularization. While the volume-outcome relationship in coronary artery bypass graft surgery is very well-documented, the technically challenging nature of off-pump surgery, the length of the learning curve associated with the operation and the higher risk profile of patients undergoing off-pump surgery in comparison with routine on-pump surgery render these results difficult to interpret. Although our review does support the idea of a volume-outcome relationship in off-pump coronary artery bypass surgery, this relationship may not be so clearly defined and requires further analysis by higher-quality studies.

Off-pump coronary artery bypass grafting attenuates morbidity and mortality for patients with low and high body mass index.

BACKGROUND: Patients at high and low body mass index have been shown to experience higher morbidity and mortality when undergoing coronary artery bypass grafting. The purpose of this research was to compare outcomes of patients at body mass index extremes who underwent coronary artery bypass grafting with or without cardiopulmonary bypass. METHODS: A retrospective review of 6801 patients with a body mass index <25 or >35 undergoing isolated, primary coronary artery bypass grafting from 1996 to 2009 at Emory Healthcare Hospitals was performed. Patients were compared by therapy either on-pump coronary artery bypass grafting (n = 3210) or off-pump coronary artery bypass grafting (n = 3591). Salvage patients or those with concomitant operations were excluded. Comparisons were made using multivariable regression analysis, using a propensity score covariate calculated from 41 preoperative risk factors. RESULTS: A total of 6801 patients, including 4312 with a body mass index <25 (off-pump coronary artery bypass grafting, n = 2083; on-pump coronary artery bypass grafting, n = 2229) and 2489 with a body mass index >35 (off-pump coronary artery bypass grafting, n = 1127; on-pump coronary artery bypass grafting, n = 1362) were included for analysis. Society of Thoracic Surgeons predicted risk of mortality was significantly higher for both body mass index strata in patients undergoing off-pump coronary artery bypass grafting (2.8% vs 3.1% for body mass index <25 [P = .043] and 1.7% vs 1.8% for body mass index >35 [P = .049]). For patients with a body mass index <25, multivariable analysis of outcomes showed a significant decrease in in-hospital mortality (adjusted odds ratio, 0.48; 95% confidence interval, 0.28-0.82), stroke (adjusted odds ratio, 0.31; 95% confidence interval, 0.18-0.56), new-onset renal failure (adjusted odds ratio, 0.59; 95% confidence interval, 0.36-0.96), and prolonged ventilation (adjusted odds ratio, 0.50; 95% confidence interval, 0.38-0.64). Long-term survival was unaffected by method of revascularization for either body mass index strata (P > .05). CONCLUSIONS: Patients with high and low body mass indices experience reduced morbidity and in-hospital mortality when undergoing off-pump coronary artery bypass grafting. Despite a higher risk profile, patients with a body mass index <25 who underwent off-pump coronary artery bypass grafting experienced a significant reduction in in-hospital mortality.

An open randomized controlled trial of median sternotomy versus anterolateral left thoracotomy on morbidity and health care resource use in patients having off-pump coronary artery bypass surgery: the Sternotomy Versus Thoracotomy (STET) trial.

OBJECTIVE: Our objective was to compare off-pump coronary artery bypass surgery carried out via a left anterolateral thoracotomy (ThoraCAB) or via a conventional median sternotomy (OPCAB). BACKGROUND: Recent advances in minimally invasive cardiac surgery have extended the technique to allow complete surgical revascularization on the beating heart via thoracotomy. METHODS: Patients undergoing nonemergency primary surgery were enrolled between February 2007 and September 2009 at 2 centers. The primary outcome was the time from surgery to fitness for hospital discharge as defined by objective criteria. RESULTS: A total of 93 patients were randomized to off-pump coronary artery bypass surgery via a median sternotomy (OPCAB) and 91 to off-pump coronary artery bypass surgery via a left anterolateral thoracotomy (ThoraCAB). The surgery was longer for patients in the ThoraCAB group (median, 4.1 vs 3.3 hours) and there were fewer with more than 3 grafts (2% vs 17%). The median time from surgery to fitness for discharge was 6 days (interquartile range, 4-7) in the ThoraCAB group versus 5 days (interquartile range, 4-7) in the OPCAB group (P = .53). The intubation time was shorter, by on average 65 minutes, in the ThoraCAB group (P = .017), although the time in intensive care was similar (P = .91). Pain scores were similar (P = .97), but more analgesia was required in the ThoraCAB group (median duration, 38.8 vs 35.5 hours, P < .001; tramadol use, 66% vs 49%, P = .024). ThoraCAB was associated with significantly worse lung function at discharge (average difference, -0.25 L, P = .01) but quality of life scores at 3 and 12 months were similar (P = .52). The average total cost was 10% higher with ThoraCAB (P = .007). CONCLUSIONS: ThoraCAB resulted in no overall clinical benefit relative to OPCAB.

Preoperative hypoalbuminemia is a major risk factor for acute kidney injury following off-pump coronary artery bypass surgery.

PURPOSE: To investigate the association between preoperative low serum albumin level and acute kidney injury (AKI) after off-pump coronary artery bypass surgery (OPCAB) METHOD: We assessed preoperative and perioperative risk factors, and preoperative serum albumin concentration in 1,182 consecutive adult patients with preoperative normal renal function who underwent OPCAB surgery. Each patient was categorized by maximal Acute Kidney Injury Network (AKIN) criteria based on creatinine changes within the first 48 h after OPCAB. Logistic regression and propensity analyses were performed to evaluate the association between preoperative low serum albumin level and postoperative AKI. RESULTS: Of the 1,182 patients, 334 (28.3%) developed AKI. Risk factors for AKI were old age, diabetes mellitus, maximal cardiovascular component of the sequential organ failure assessment score, perioperative transfusion, and postoperative C-reactive protein concentration. The risk of AKI was negatively correlated with the volume of crystalloid infused during surgery. A preoperative serum albumin level of <4.0 g/dl was independently associated Ith postoperative AKI [multivariable logistic analysis: odds ratio (OR) 1.83, 95 % confidence interval (CI) 1.27-2.64; P = 0.001; propensity analysis: OR 1.62, 95 % CI 1.12-2.35; P = 0.011). AKI was associated with prolonged stay in the intensive care unit and hospital and a high mortality rate. CONCLUSIONS: Preoperative low serum albumin level is an independent risk factor for AKI, and postoperative AKI is associated with poor outcomes after OPCAB in patients with preoperative normal renal function.

Rationale and design of the coronary artery bypass grafting surgery off or on pump revascularization study: a large international randomized trial in cardiac surgery.

BACKGROUND: Uncertainty remains regarding the benefits and risks of the technique of operating on a beating heart (off pump) for coronary artery bypass grafting (CABG) surgery versus on-pump CABG. Prior trials had few events and relatively short follow-up. There is a need for a large randomized, controlled trial with long-term follow-up to inform both the short- and long-term impact of the 2 approaches to CABG. METHODS: We plan to randomize 4,700 patients in whom CABG is planned to undergo the procedure on pump or off pump. The coprimary outcomes are a composite of total mortality, myocardial infarction (MI), stroke, and renal failure at 30 days and a composite of total mortality, MI, stroke, renal failure, and repeat revascularization at 5 years. We will also undertake a cost-effectiveness analysis at 30 days and 5 years after CABG surgery. Other outcomes include neurocognitive dysfunction, recurrence of angina, cardiovascular mortality, blood transfusions, and quality of life. RESULTS: As of May 3, 2011, CORONARY has recruited >3,884 patients from 79 centers in 19 countries. Currently, patient's mean age is 67.6 years, 80.7% are men, 47.0% have a history of diabetes, 51.4% have a history of smoking, and 34.4% had a previous MI. In addition, 20.9% of patients have a left main disease, and 96.6% have double or triple vessel disease. CONCLUSIONS: CORONARY is the largest trial yet conducted comparing off-pump CABG to on-pump CABG. Its results will lead to a better understanding of the safety and efficacy of off-pump CABG.