Five-year follow-up of a randomized comparison between off-pump and on-pump stable multivessel coronary artery bypass grafting. The MASS III Trial

Five-year outcomes of off and on-pump CABG: Insights from PROMOTE Patency Trial

BACKGROUND

There are limited studies reporting follow-up outcome data comparing of off-pump coronary artery bypass (OPCAB) with on-pump (ONCAB) technique. The aim of the study was to report the 5-year clinical outcomes of OPCAB and ONCAB in a post hoc analysis of the PROMOTE patency trial.

METHODS

From March 2016 through March 2017, a total of 321 patients undergoing coronary artery bypass grafting (CABG) were randomised to either the off-pump or the on-pump technique. Data on all-cause mortality, myocardial infarction (MI), cerebrovascular accident (CVA), repeat revascularisation and need for renal replacement therapy (RRT) were recorded. The composite and each of these individual outcomes are reported at 5-year interval.

RESULTS

The mean follow-up period was 65.9 months (±3.39). A total of 275 (85.93%) patients followed up at the 5-year interval who underwent CABG by the off-pump (n  =  158) and the on-pump (n  =  162) technique. The all-cause mortality was 8.9% and 5.7% in ONCAB and OPCAB, respectively (hazard ratio [HR]  =  0.62; 95% confidence interval [CI] 0.25-1.57, p  =  0.31). The composite of all-cause mortality, non-fatal MI, non-fatal CVA, RRT and need for repeat revascularisation was comparable in both groups (7.1% vs. 11.9%, HR  =  0.57; 95% CI 0.25-1.31, p  =  0.18 in OPCAB and ONCAB, respectively). The rates of 5-year non-fatal MI (p  =  0.2), non-fatal CVA (p  =  0.36) and need for repeat revascularisation (p  =  1) were similar in both groups. A sub-group analysis did not show any significant interaction or effect modification with either of the techniques.

CONCLUSIONS

The 5-year clinical outcomes of OPCAB are comparable to ONCAB in low-risk patients undergoing CABG. Off-pump coronary artery bypass had no additional benefit in any subgroup.

Early and mid-term outcomes of off-pump versus on-pump coronary artery bypass surgery in patients with triple-vessel coronary artery disease: a randomized controlled trial

BACKGROUND AND AIM OF THE STUDY

Several studies have compared early and late outcomes of on-pump coronary artery bypass grafting (CABG) and off-pump CABG. However, there is still an ongoing debate on this matter, especially in patients with triple-vessel coronary artery disease (3VD).

METHODS

We randomly assigned 274 consecutive patients with 3VD to two equal groups to undergo on-pump CABG or off-pump CABG. The primary outcome was major adverse cardiac and cerebrovascular events (MACCE), including all-cause mortality, acute coronary syndrome, stroke or transient ischemic attack, and the need for repeat revascularization. The secondary outcomes were postoperative infection, ventilation time, ICU admission duration, hospital stay length, and renal failure after surgery.

RESULTS

The median follow-up duration was 31.2 months (range 24.6-35.2 months). The mean age of patients was 61.4 ± 9.3 years (range: 38-86), and 207 (78.7%) were men. There were 15 (11.2%) and 9 (7.0%) MACCE occurrences in on-pump and off-pump groups, respectively (P value = 0.23). MACCE components including all-cause death, non-fatal MI, CVA, and revascularization did not significantly differ between on-pump and off-pump groups. We observed no difference in the occurrence of MACCE between off-pump and on-pump groups in multivariable regression analysis (HR = 0.57; 95% CI 0.24-1.32; P value = 0.192). There were no statistical differences in postoperative outcomes between the off-pump and on-pump CABG groups.

CONCLUSIONS

Off-pump CABG is an equal option to on-pump CABG for 3VD patients with similar rates of MACCE and postoperative complications incidence when surgery is performed in the same setting by an expert surgeon in both methods. (IRCT20190120042428N1).

Risk of perioperative stroke and cerebral autoregulation monitoring: a systematic review

BACKGROUND

Perioperative stroke, delirium, and cognitive impairment could be related to management and to variations in blood pressure control, cerebral hypoperfusion and raised blood volume. Cerebral autoregulation (CAR) is a mechanism to maintain cerebral perfusion through the control of the vascular tone and hemodynamic reactions in the circulation.

OBJECTIVE

The present systematic review addresses the relationship between impaired CAR and perioperative stroke by evaluating the rate of neurological complications after surgery in studies in which perioperative CAR was tested or monitored.

METHODS

We included randomized clinical trials and prospective observational studies. All studies had adjusted the relative risk, hazard ratio or 95% confidence interval (95%CI) values. These estimation effects were tested using random-effects models. Heterogeneity among the selected studies was assessed using the Higgins and Thompson I² statistics.

RESULTS

The Web of Science, PubMed and EMBASE electronic databases were searched to retrieve articles. A total of 4,476 studies published between 1983 and 2019 were analyzed, but only 5 qualified for the data extraction and were included in the final analysis. The combined study cohort comprised 941 patients who underwent CAR monitoring during surgical procedures. All studies provided information about perioperative stroke, which equated to 16% (158 of 941) of the overall patient population.

CONCLUSION

The present meta-analysis showed evidence of the impact of CAR impairment in the risk of perioperative stroke. On the pooled analysis, blood fluctuations or other brain insults large enough to compromise CAR were associated with the outcome of stroke (odds ratio [OR]: 2.26; 95%CI: 1.54-2.98; p < 0.0001).

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered.

STRUCTURE

Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

Representation of Women in Randomized Trials in Cardiac Surgery: A Meta-Analysis

Background

Women have traditionally been underrepresented in randomized clinical trials (RCTs). We performed a systematic evaluation of the inclusion of women in cardiac surgery RCTs published in the past 2 decades.

Methods and Results

MEDLINE, EMBASE, and the Cochrane Library were searched (2000 to July 2020) for RCTs written in English, comparing ≥2 adult cardiac surgical procedures. The percentage of women enrolled and its association with year of publication, sample size, mean age, funding source, geographic location, number of sites involved, and interventions tested were analyzed using a meta‐analytic approach. Fifty‐one trials were included. Of 25 425 total patients, 5029 were women (20.8%; 95% CI, 17.6–24.4; range, 0.5%–57.9%). The proportion of women dropped significantly during the study period (29.6% in 2000 versus 13.1% in 2019, P<0.001). Women were significantly more represented in European trials (26.2%; 95% CI, 21.2–31.9), and less represented in trials of coronary bypass surgery versus other interventions (16.8%; 95% CI, 12.3–22.7 versus 33.6%; 95% CI, 27.4–40.5; P=0.0002) and in trials enrolling younger patients (P=0.009); the percentage of women was higher in industry‐sponsored versus non‐industry sponsored trials (31.7%; 95% CI, 27.2–36.6 versus 15.5%; 95% CI, 10.0–23.2; P=0.0004) and was not associated with trial sample size (P=0.52) or study design (multicenter versus monocenter: P=0.22). After exclusion of trials conducted at Veteran Affairs centers, women representation was 24.4% (95% CI, 21.1–28.0; range, 10.4%–57.9%), with no significant changes during the study period.

Conclusions

The proportion of women in cardiac surgery trials is low and likely inadequate to provide meaningful estimates of the treatment effect.

Right ventricular injury and pulmonary embolism: The perils of deep intramyocardial left anterior descending artery dissection in off-pump coronary artery bypass grafting

An inadvertent vent in the right ventricle (RV) resulted during dissection of a deep intramyocardial left anterior descending coronary artery (LAD), during off-pump coronary artery bypass grafting (OPCAB), led to pulmonary artery air embolism and hemodynamic instability, requiring conversion to cardiopulmonary bypass (CPB) prior to repair. This required a special maneuver in positioning the patient to identify the RV injury and prevent the pulmonary air embolism.

Current Status of Off-Pump Coronary Artery Bypass

PURPOSE

Off-pump coronary arterial bypass grafting (OPCAB) has become a common practice for coronary artery bypass grafting (CABG) in Japan, with approximately 65% CABG procedures currently being performed using OPCAB. However, it is unclear whether OPCAB is superior in terms of associated mortality, incidence of complications, graft patency rate, and long-term outcomes compared with conventional CABG (CCABG).

METHODS

Literature consideration was performed, mainly based on observational studies involving large samples and randomized controlled trials (RCTs).

RESULTS

Many RCTs indicated that the acute-phase and long-term mortality rates were comparable between CCABG and OPCAB or that OPCAB was inferior to CCABG. In contrast, many observational studies indicated that OPCAB was superior to CCABG.

CONCLUSION

CABG is a delicate procedure, the outcomes of which vary in accordance with the patient's condition as well as the level of expertise of the associated institution and surgeon. In the future, we hope that reports will emerge with excellent results, including long-term results, from Japanese institutions experienced in performing OPCAB.

Patients who develop post-operative atrial fibrillation have reduced survival after off-pump coronary artery bypass grafting

Objective

Post-operative atrial fibrillation (POAF) increases hospital stay, resource utilization, morbidity, and mortality. However, there is paucity of data about its effect in Indian patients undergoing off-pump coronary artery bypass grafting (CABG).

Methods

Seven hundred forty-eight patients underwent off-pump CABG from January 2015 to December 2016 (24 months). One hundred twenty-seven patients (16.7%) developed POAF. In an effort to mitigate the effects of wider risk factors on perioperative outcomes, a separate sub-analysis of patients based on risks quantified by EuroSCORE II (<> 3) was also performed.

Results

Age > 60 years and development of sepsis were the independent predictors for the development of POAF. Thirty-day/mortality rate was higher in the POAF group (7.1% vs. 1.4%; p value < 0.001). POAF was associated with increased ICU and hospital stay and increased incidence of stroke and renal dysfunction. The survival was significantly lower in the POAF group compared with the normal sinus rhythm (NSR) (3-year survival in POAF was 81.3% vs. 94.4% in the NSR group; Hazard ratio (HR) 3.867 (1.989–7.516)). Intra-aortic balloon pump (IABP) usage, age ≥ 60 years and sepsis were independent predictors for the development of POAF in low-risk patients. For the NSR group, 1-year survival was 98% and 3-year survival was 95.7%. For the POAF group, 1-year survival was 94.4% and 3-year survival was 84.0% (HR. 3.794 (1.897–7.591)).

Conclusion

The incidence of POAF was lower than reported in the wider global literature. Increasing age and development of post-operative sepsis were strong independent predictors of POAF. POAF increases the morbidity; length of hospital stay and these patients show decreased survival after off-pump CABG.

Long-Term Graft Patency After Off-Pump and On-Pump Coronary Artery Bypass: A CORONARY Trial Cohort

BACKGROUND

Randomized controlled trials have compared the early and midterm prognosis of on-pump coronary artery bypass grafting (CABG) and off-pump CABG. However the results are controversial, and there is limited information on graft patency and long-term outcomes.

METHODS

Between May 2007 and October 2011, 349 patients were randomized to off-pump or on-pump CABG as part of the CORONARY trial at Fuwai Hospital. The primary outcome was coronary bypass graft patency, which was assessed at a mean of 6.7 ± 1.7 years after surgery by multidetector computed tomography. A secondary endpoint was a composite outcome of death, nonfatal myocardial infarction, repeat coronary revascularization, or stroke; mean follow-up was 6.5 ± 1.7 years. Graft patency was compared between the off-pump and on-pump CABG treatment arms in 206 patients with follow-up computed tomography.

RESULTS

During the follow-up period 107 patients were in the off-pump CABG group and 99 in the on-pump group. These patients underwent a total of 723 grafts, and the overall rate of graft patency did not differ significantly between the off-pump and on-pump groups (87.4% vs 88.9%, P = .527). The patency rate of the posterior descending branch was lower than average. Higher incidences of mortality, nonfatal myocardial infarction, and repeat revascularization were found in the off-pump patients; however it did not reach significance.

CONCLUSIONS

There were no statistical differences in graft patency rates in off-pump versus on-pump CABG patients during long-term follow-up. The on-pump CABG group appeared to have a better long-term prognosis even with no statistical differences for the limited study population.

Prevalence and Impact of Treatment Crossover in Cardiac Surgery Randomized Trials: A Meta-Epidemiologic Study

Background Crossover dilutes treatment effect and reduces statistical power of intention-to-treat analysis. We examined incidence and impact on cardiac surgery randomized controlled trial (RCT) outcomes of crossover from experimental to control interventions, or vice versa. Methods and Results MEDLINE, EMBASE, and Cochrane Library were searched, and RCTs (≥100 patients) comparing ≥2 adult cardiac surgical interventions were included. Crossover from the initial treatment assignment and relative risks (RRs) for each trial's primary end point and mortality at longest available follow-up were extracted. All RRs were calculated as >1 favored control group and <1 favored experimental arm. Primary outcome was the effect estimate for primary end point of each RCT, and secondary outcome was all-cause mortality; both were appraised as RR at the longest follow-up available. Sixty articles reporting on 47 RCTs (25 440 patients) were identified. Median crossover rate from experimental to control group was 7.0% (first quartile, 2.0%; third quartile, 9.7%), whereas from control to experimental group, the rate was 1.3% (first quartile, 0%; third quartile, 3.6%). RRs for primary end point and mortality were higher in RCTs with higher crossover rate from experimental to control group (RR, 1.01 [95% CI, 0.94-1.07] versus RR, 0.80 [95% CI, 0.66-0.97] and RR, 1.02 [95% CI, 0.95-1.11] versus RR, 0.94 [95% CI, 0.82-1.07], respectively). Crossover from control to experimental group did not alter effect estimates for primary end point or mortality (RR, 0.82 [95% CI, 0.63-1.05] versus RR, 0.95 [95% CI, 0.86-1.04] and RR, 0.88 [95% CI, 0.73-1.07] versus RR, 1.02 [95% CI, 0.95-1.09], respectively). Conclusions Crossover from experimental to control group is associated with outcomes of cardiac surgery RCTs. Crossover should be minimized at designing stage and carefully appraised after study completion.

Off- vs. On-Pump Coronary Artery Bypass Grafting Long-Term Survival is Driven by Incompleteness of Revascularisation

BACKGROUND

Off-pump coronary artery bypass grafting (CABG) negates the requirement for extracorporeal circulation used with the traditional on-pump approach. However, off-pump CABG is technically more challenging and may theoretically lead to less complete revascularisation. Recent data suggests a prognostic benefit for traditional on-pump CABG, but the mechanism for this remains unclear. We hypothesised that the inferior outcomes with off-pump CABG could be driven by the need for repeat revascularisation, with this benefit only becoming clear at long-term follow-up. We therefore evaluated short, medium and long-term outcomes of patients undergoing revascularisation with on vs. off-pump CABG.

METHODS

Electronic databases were searched to identify suitable randomised controlled trials enrolling ≥100 patients in each arm. Clinical outcomes were extracted at 30-days, 12-months or >4years. The primary outcome was long-term all-cause death, while secondary outcomes included 30-day, 12-month and >4-year cardiac death, stroke, myocardial infarction or revascularisation.

RESULTS

Thirteen (13) studies comprising 13,234 patients were included. Off-pump CABG was associated with an increased risk of all-cause death (Odds Ratio [OR] 1.18, 95% confidence interval [CI] 1.02-1.32, p=0.01) and repeat bypass surgery (OR 2.57, 95%CI 1.23-5.39, p=0.01) at long-term follow-up. A significant, increased requirement for revascularisation in off-pump was seen at 12-month follow-up (OR 1.59, 95%CI 1.09-2.33, p=0.02). No differences were noted between groups at 30-days, 12-months and >4years for myocardial infarction or stroke.

CONCLUSIONS

Off-pump CABG is associated with significantly higher rates of all-cause mortality rate at long-term follow-up. These outcomes demonstrate a temporal relationship that may be driven by a greater requirement for repeat revascularisation at 1- and 5-year follow-up.

STUDY REGISTRATION

CRD42018102019 (PROSPERO).

Behavior of Ultrasensitive C-Reactive Protein in Myocardial Revascularization with and without Cardiopulmonary Bypass

Objective

To analyze the inflammation resulting from myocardial revascularization techniques with and without cardiopulmonary bypass, based on ultrasensitive C-reactive protein (US-CRP) behavior.

Methods

A prospective non-randomized clinical study with 136 patients was performed. Sixty-nine patients were enrolled for Group 1 (on-pump coronary artery bypass - ONCAB) and 67 patients were assigned to Group 2 (off-pump coronary artery bypass - OPCAB). All study participants had blood samples collected for analysis of glucose, triglycerides, creatinine, total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and creatinephosphokinase (CPK) in the preoperative period. The samples of creatinephosphokinase MB (CKMB), troponin I (TnI) and US-CRP were collected in the preoperative period and at 6, 12, 24, 36, 48 and 72 hours after surgery. We also analyzed the preoperative biological variables of each patient (age, smoking, diabetes mellitus, left coronary trunk lesion, body mass index, previous myocardial infarction, myocardial fibrosis). All angiographically documented patients with >70% proximal multiarterial stenosis and ischemia, documented by stress test or classification of stable angina (class II or III), according to the Canadian Cardiovascular Society, were included. Reoperations, combined surgeries, recent acute myocardial infarction, recent inflammatory disease, deep venous thrombosis or recent pulmonary thromboembolism, acute kidney injury or chronic kidney injury were not included.

Results

Correlation values between the US-CRP curve and the ONCAB group, the treatment effect and the analyzed biological variables did not present expressive results. Laboratory variables were evaluated and did not correlate with the applied treatment (P>0.05).

Conclusion

The changes in the US-CRP at each moment evaluated from the postoperative period did not show any significance in relation to the surgical technique applied.

Off- Versus On-Pump Coronary Surgery and the Effect of Follow-Up Length and Surgeons' Experience: A Meta-Analysis

Background The debate on the relative benefits of off-pump and on-pump coronary artery bypass surgery ( OPCABG and ONCABG ) is still open. We aimed to provide an updated and complete summary of the evidence on the differences between OPCABG and ONCABG and to explore whether the length of the follow-up and the surgeons' experience in OPCABG modify the comparative results. Methods and Results All randomized clinical trials comparing OPCABG and ONCABG were included. Primary outcome was follow-up mortality. Secondary outcomes were operative mortality, perioperative stroke, perioperative myocardial infarction, and late repeated revascularization. Subgroup analyses were performed based on the length of the follow-up and the percentage of crossover from the OPCABG group (used as a surrogate of surgeon experience with OPCABG ). One hundred four trials were included (20 627 patients, OPCABG : 10 288; ONCABG : 10 339). Weighted mean follow-up time was 3.7 years (range 1-7.5 years). OPCABG was associated with a higher risk of follow-up mortality (incidence rate ratio 1.11, 95% confidence interval 1.00-1.23, P=0.05). The difference was significant only for trials with mean follow-up of ≥3 years and for studies with a crossover rate of ≥10%. There was a trend toward lower risk of perioperative stroke and higher need for late repeated revascularization in the OPCABG arm. Conclusions OPCABG is associated with a higher incidence of incomplete revascularization, an increased need for repeated revascularization, and decreased midterm survival compared with ONCABG . Surgeon inexperience in OPCABG is associated with late mortality.

Ten-Year Follow-Up of Off-Pump and On-Pump Multivessel Coronary Artery Bypass Grafting: MASS III

It was a randomized trial, and 308 patients undergoing revascularization were randomly assigned: 155 to off-pump coronary artery bypass (OPCAB) and 153 to on-pump coronary artery bypass (ONCAB). End points were freedom from death, myocardial infarction, revascularization, and cerebrovascular accidents. The rates for 10-year, event-free survival for ONCAB versus OPCAB were 69.6% and 64%, (hazard ratio [HR]: 0.88; 95% confidence interval [CI] 0.86-1.02; P = .41), respectively. Adjusted Cox proportional hazard ratio was similar (HR: 0.92; 95% CI 0.61-1.38, P = .68). A difference occurred between the duration of OPCAB and ONCAB, respectively (4.9 ± 1.5 vs 6.6 ± 1.1 h, P < .001). Statistical differences occurred between OPCAB and ONCAB in the length of intensive care unit (ICU) stay (20 ± 2.5 vs 48 ± 10 hours, P < .001), time to extubation (5.5 ± 4.2 vs 10.2 ± 3.5 hours, P < .001), hospital stay (6.7 ± 1.4 vs 9.2 ± 1.3 days, P < .001), higher incidence of atrial fibrillation (AF; 33 vs 5 patients, P < .001), and blood requirements (46 vs 64 patients, P < .001). Grafts per patient was higher in ONCAB (3.15 vs 2.55 grafts, P < .001). No difference existed between the groups in primary composite end points at 10-year follow-up. Although OPCAB surgery was related to a lower number of grafts and higher incidence of AF, it had no effects related to long-term outcomes.

Meta-Analysis of Repeat Revascularization of Off-Pump and On-Pump Coronary Artery Bypass Surgery

BACKGROUND

There is an ongoing debate focusing on clinical outcomes after off-pump coronary artery bypass graft surgery (OPCABG) and on-pump coronary artery bypass graft surgery (ONCABG). The objective of the present meta-analysis is to update and compare repeat revascularization rates between OPCABG and ONCABG procedures.

METHODS

Data sources including PubMed, EMBASE, Cochrane Library, and ISI Web of Knowledge were searched between 1966 and October 2017. Studies considered for inclusion should conform to the following criteria: prospective randomized clinical trials comparing OPCABG and ONCABG. Outcome should include repeat revascularization rate at the time of 1-month, 1-year, or 5-year follow-up.

RESULTS

A literature search yielded 11 randomized controlled trials, and a total of 11,246 patients were randomly allocated to OPCABG or ONCABG procedures. Pooled analysis demonstrated a statistically significant 53% increase in repeat revascularization rate at 1-year follow-up with OPCABG relative to ONCABG in the fixed effects model (odds ratio 1.53, 95% confidence interval: 1.17 to 2.00, p = 0.002), whereas there was no significant difference in repeat revascularization rate at 5-year follow-up between OPCABG and ONCABG in the fixed effects model (OR 1.16, 95% confidence interval: 0.95 to 1.41, p = 0.14). In general, exclusion of any single trial did not affect repeat revascularization rate at 1-year and 5-year follow-up. There was no evidence of significant publication bias.

CONCLUSIONS

The result of our meta-analysis suggests that compared with ONCABG, OPCABG increases repeat revascularization rate at 1-year follow-up, but does not affect that of 5-year follow-up.

Perioperative stroke: pathophysiology and management

Although perioperative stroke is uncommon during low-risk non-vascular surgery, if it occurs, it can negatively impact recovery from the surgery and functional outcome. Based on the Society for Neuroscience in Anesthesiology and Critical Care Consensus Statement, perioperative stroke includes intraoperative stroke, as well as postoperative stroke developing within 30 days after surgery. Factors related to perioperative stroke include age, sex, a history of stroke or transient ischemic attack, cardiac surgery (aortic surgery, mitral valve surgery, or coronary artery bypass graft surgery), and neurosurgery (external carotid-internal carotid bypass surgery, carotid endarterectomy, or aneurysm clipping). Concomitant carotid and cardiac surgery may further increase the risk of perioperative stroke. Preventive strategies should be individualized based on patient factors, including cerebrovascular reserve capacity and the time interval since the previous stroke.

Meta-Analysis Comparing ≥10-Year Mortality of Off-Pump Versus On-Pump Coronary Artery Bypass Grafting

Off-pump coronary artery bypass grafting (CABG) is suggested to be associated with an increase in long-term (≥5-year) all-cause mortality. To determine whether off-pump CABG is associated with an increase in very long-term (≥10-year) all-cause mortality, we performed a meta-analysis of propensity-score matched observational comparative studies of off-pump versus on-pump CABG. MEDLINE and EMBASE were searched through May 2017. A hazard ratio of follow-up (including early) all-cause mortality for off-pump versus on-pump CABG was extracted from each individual study. Study-specific estimates were combined using inverse variance-weighted averages of logarithmic hazard ratios in the random-effects model. Of 164 potentially relevant studies, our search identified 16 propensity-score matched observational comparative studies of off-pump versus on-pump CABG with ≥10-year follow-up enrolling a total of 82,316 patients. A pooled analysis of all the 16 studies demonstrated that off-pump CABG was significantly associated with an increase in all-cause mortality (hazard ratio 1.07, 95% confidence interval 1.03 to 1.12, p for effect = 0.0008; p for heterogeneity = 0.30, I² = 12%). In a sensitivity analysis, exclusion of any single hazard ratio from the analysis (leave-one-out meta-analysis) did not substantively alter the overall result. There was no evidence of a significant publication bias. In conclusion, off-pump CABG is associated with an increase in very long-term (≥10 years) all-cause mortality compared with on-pump CABG.

Efficacy and effectiveness of on- versus off-pump coronary artery bypass grafting: A meta-analysis of mortality and survival

BACKGROUND

Despite many studies comparing on- versus off-pump coronary artery bypass graft (CABG), there is no consensus as to whether one of these techniques offers patients better outcomes.

METHODS

We searched PubMed from inception to June 30, 2015, and identified additional studies from bibliographies of meta-analyses and reviews. We identified 42 randomized controlled trials (RCTs) and 31 rigorously adjusted observational studies (controlling for the Society of Thoracic Surgeons-recognized risk factors for mortality) reporting mortality for off-pump versus on-pump CABG at specified time points. Trial data were extracted independently by 2 researchers using a standardized form. Differences in probability of mortality (DPM) were estimated for the RCTs and observational studies separately and combined, for time points ranging from 30 days to 10 years.

RESULTS

RCT-only data showed no significant differences at any time point, whereas observational-only data and the combined analysis showed short-term mortality favored off-pump CABG (n = 1.2 million patients; 36 RCTs, 26 observational studies; DPM [95% confidence interval (CI)], -44.8% [-45.4%, -43.8%]) but that at 5 years it was associated with significantly greater mortality (n = 60,405 patients; 3 RCTs, 5 observational studies; DPM [95% CI], 10.0% [5.0%, 15.0%]). At 10 years, only observational data were available, and off-pump CABG showed significantly greater mortality (DPM [95% CI], 14.0% [11.0%, 17.0%]).

CONCLUSIONS

Evidence from RCTs showed no differences between the techniques, whereas rigorously adjusted observational studies (with >1.1 million patients) and the combined analysis indicated that off-pump CABG offers lower short-term mortality but poorer long-term survival. These results suggest that, in real-world settings, greater operative safety with off-pump CABG comes at the expense of lasting survival gains.

Five-Year Outcomes after On-Pump and Off-Pump Coronary-Artery Bypass

BACKGROUND

Coronary-artery bypass grafting (CABG) surgery may be performed either with cardiopulmonary bypass (on pump) or without cardiopulmonary bypass (off pump). We report the 5-year clinical outcomes in patients who had been included in the Veterans Affairs trial of on-pump versus off-pump CABG.

METHODS

From February 2002 through June 2007, we randomly assigned 2203 patients at 18 medical centers to undergo either on-pump or off-pump CABG, with 1-year assessments completed by May 2008. The two primary 5-year outcomes were death from any cause and a composite outcome of major adverse cardiovascular events, defined as death from any cause, repeat revascularization (CABG or percutaneous coronary intervention), or nonfatal myocardial infarction. Secondary 5-year outcomes included death from cardiac causes, repeat revascularization, and nonfatal myocardial infarction. Primary outcomes were assessed at a P value of 0.05 or less, and secondary outcomes at a P value of 0.01 or less.

RESULTS

The rate of death at 5 years was 15.2% in the off-pump group versus 11.9% in the on-pump group (relative risk, 1.28; 95% confidence interval [CI], 1.03 to 1.58; P=0.02). The rate of major adverse cardiovascular events at 5 years was 31.0% in the off-pump group versus 27.1% in the on-pump group (relative risk, 1.14; 95% CI, 1.00 to 1.30; P=0.046). For the 5-year secondary outcomes, no significant differences were observed: for nonfatal myocardial infarction, the rate was 12.1% in the off-pump group and 9.6% in the on-pump group (P=0.05); for death from cardiac causes, the rate was 6.3% and 5.3%, respectively (P=0.29); for repeat revascularization, the rate was 13.1% and 11.9%, respectively (P=0.39); and for repeat CABG, the rate was 1.4% and 0.5%, respectively (P=0.02).

CONCLUSIONS

In this randomized trial, off-pump CABG led to lower rates of 5-year survival and event-free survival than on-pump CABG. (Funded by the Department of Veterans Affairs Office of Research and Development Cooperative Studies Program and others; ROOBY-FS ClinicalTrials.gov number, NCT01924442 .).

Off-pump versus on-pump coronary artery bypass grafting in patients with diabetes: a meta-analysis

AIMS

The effects of off-pump CABG (OFF-CABG) versus on-pump CABG (ON-CABG) in diabetic patients remain controversial. The aim of our study was to compare mortality and postoperative morbidity between OFF-CABG and ON-CABG for diabetic patients.

METHODS

Electronic databases including PubMed, EMBASE and Cochrane Library for studies investigating clinical outcomes of OFF-CABG versus ON-CABG in diabetic patients were searched, collecting data from inception until June 2016. We pooled the odds ratios from individual studies and performed heterogeneity, quality assessment and publication bias analysis.

RESULTS

A total of 543,220 diabetic patients in 10 studies were included. The overall mortality (OR, 0.87; 95% CI, 0.58-1.31; p = 0.50) was comparable between the OFF-CABG and ON-CABG. OFF-CABG was associated with significantly fewer cerebrovascular accidents (OR, 0.45; 95% CI, 0.31-0.65; p < 0.0001), bleeding complications (OR, 0.59; 95% CI, 0.43-0.80; p < 0.001) and pulmonary complications. However, no differences in myocardial infarction (OR, 0.76; 95% CI, 0.52-1.12; p = 0.16), renal failure (OR, 0.74; 95% CI, 0.50-1.11; p = 0.14) and other postoperative morbidity outcomes were found.

CONCLUSIONS

OFF-CABG significantly reduces the incidence of postoperative cerebrovascular accidents and bleeding complications compared with ON-CABG in diabetic patients. No differences were found regarding mortality, myocardial infarction and renal failure between these two techniques. Our study suggests that OFF-CABG may be an optimal strategy for diabetic patients although adequately powered randomized trials are needed to further verify the finding.

Minimally invasive coronary artery bypass grafting: a systematic review

To minimize surgical morbidity in coronary artery bypass grafting, minimally invasive cardiac surgery has gained popularity. Minimally invasive coronary artery bypass grafting offers unique advantages compared to conventional off-pump coronary artery bypass or minimally invasive direct coronary artery bypass in that it enables the surgeon to harvest and graft bilateral internal thoracic arteries via a small thoracotomy while being conducted completely off-pump. This review focuses on current evidence behind off-pump coronary artery bypass, multi-arterial revascularization, patient populations that would most benefit from bilateral internal thoracic artery minimally invasive coronary artery bypass grafting, the surgical technique, and early outcomes. By overcoming the perceived inability to utilize bilateral internal thoracic arteries in minimally invasive coronary artery bypass grafting, the new technique further expands the armamentarium of surgeons and cardiologists. Hybrid coronary revascularization with bilateral internal thoracic artery minimally invasive coronary artery bypass grafting further augments the appeal of the next generation of minimally invasive cardiac surgery.

Five-Year Outcomes after Off-Pump or On-Pump Coronary-Artery Bypass Grafting

BACKGROUND

We previously reported that there was no significant difference at 30 days or at 1 year in the rate of the composite outcome of death, stroke, myocardial infarction, or renal failure between patients who underwent coronary-artery bypass grafting (CABG) performed with a beating-heart technique (off-pump) and those who underwent CABG performed with cardiopulmonary bypass (on-pump). We now report the results at 5 years (the end of the trial).

METHODS

A total of 4752 patients (from 19 countries) who had coronary artery disease were randomly assigned to undergo off-pump or on-pump CABG. For this report, we analyzed a composite outcome of death, stroke, myocardial infarction, renal failure, or repeat coronary revascularization (either CABG or percutaneous coronary intervention). The mean follow-up period was 4.8 years.

RESULTS

There were no significant differences between the off-pump group and the on-pump group in the rate of the composite outcome (23.1% and 23.6%, respectively; hazard ratio with off-pump CABG, 0.98; 95% confidence interval [CI], 0.87 to 1.10; P=0.72) or in the rates of the components of the outcome, including repeat coronary revascularization, which was performed in 2.8% of the patients in the off-pump group and in 2.3% of the patients in the on-pump group (hazard ratio, 1.21; 95% CI, 0.85 to 1.73; P=0.29). The secondary outcome for the overall period of the trial - the mean cost in U.S. dollars per patient - also did not differ significantly between the off-pump group and the on-pump group ($15,107 and $14,992, respectively; between-group difference, $115; 95% CI, -$697 to $927). There were no significant between-group differences in quality-of-life measures.

CONCLUSIONS

In our trial, the rate of the composite outcome of death, stroke, myocardial infarction, renal failure, or repeat revascularization at 5 years of follow-up was similar among patients who underwent off-pump CABG and those who underwent on-pump CABG. (Funded by the Canadian Institutes of Health Research; CORONARY ClinicalTrials.gov number, NCT00463294 .).

Circulating Biomarkers Predictive of Postoperative Atrial Fibrillation

Postoperative atrial fibrillation (PoAF), a common complication of cardiac surgery, contributes significantly to morbidity, mortality, and increasing healthcare costs. Despite advances in surgical and medical management, the overall incidence of PoAF has not changed significantly, partly because of the limited understanding of mechanisms underlying acute surgery-related factors, such as myocardial injury, inflammation, sympathetic activation, and oxidative stress, which play an important role in the initiation of PoAF, whereas a preexisting atrial substrate appears to be more important in the maintenance of this dysrhythmia. Thus, in a majority of patients, PoAF becomes a manifestation of an underlying arrhythmogenic substrate that is unmasked after acute surgical stress. As such, the ability to identify which patients have this proarrhythmic substrate and are, therefore, at high risk for developing AF postoperatively, is important for the improved selection for prophylactic interventions, closer monitoring for complications, and establishing the probability of AF in the long term. This review highlights the role of the underlying substrate in promoting PoAF, proposed mechanisms, and the potential role of serum biomarkers to identify patients at risk for PoAF.

Impact of off-pump coronary artery bypass grafting on survival: current best available evidence

The superiority of either off-pump (OPCAB) or on-pump (ONCAB) coronary artery bypass grafting (CABG) remains unclear despite a large body of literature evidence comparing the two approaches. The potential advantages of avoiding cardiopulmonary bypass (CPB), minimizing aortic manipulation and maintaining pulsatile flow may be associated with reduced inflammatory responses and embolic events. Numerous studies compared OPCAB with ONCAB and the cumulative data have been presented in meta-analyses of both randomized and observational studies. Although there is an abundance of data with respect to the operative morbidity and mortality and the short-term outcomes associated with these two strategies, not much is known about how they impact long-term survival and recurrence of myocardial ischaemic events. Recent studies and meta-analyses have focused on long-term survival and major secondary outcomes in OPCAB vs. ONCAB within the general population. Significant limitations in methodology, however, have raised concerns about the strength of several randomized trials with restrictive inclusion criteria that reduced the populations to those at low risk only, thus creating result bias. Here, we present a review of the best available evidence with a focus on long-term outcomes.

Is off-pump technique a safer procedure for coronary revascularization? A propensity score analysis of 20 years of experience

OBJECTIVES

We aim to describe our experience in coronary artery bypass grafting (CABG) with or without cardiopulmonary bypass by comparing intraoperative and postoperative outcomes.

METHODS

From January 1993 to June 2013, 3097 patients underwent consecutive emergency and scheduled CABG surgery. A total of 1770 patients underwent on-pump CABG (ONCABG) and 1327 off-pump CABG (OPCABG). A propensity score matching was performed to identify appropriate matched-pair patients; univariable and multivariable logistic regression analyses were performed to assess significant predictors of hospital and 30-day morbidity and mortality composite end-points. Morbidity composite end-point was defined as any renal, pulmonary, cardiovascular and neurological complication that occurred during hospital stay. We collected all-cause mortality data during the study period.

RESULTS

We identified 1004 patients in each group. There were no significant differences in thirty day mortality, 2.8 vs 3.8%, in OPCABG and ONCABG, respectively (P = 0.21). Cardiovascular, neurological, respiratory and renal complications were more frequent in the ONCABG group: 13.9 vs 8.7% (P < 0.001), 3.9 vs 2.2% (P = 0.03), 13.5 vs 7.5% (P < 0.001), 7.1 vs 5.3% (P = 0.095), respectively. The long-term all-cause mortality rate was 12.3 vs 12.9% in the OPCABG versus ONCABG group (P = 0.42), respectively. In both uni- and multivariable analysis preoperative renal failure, chronic obstructive pulmonary disease and ONCABG were independent predictors of mortality and morbidity composite end-points.

CONCLUSIONS

OPCABG is associated with less postoperative morbimortality and shorter hospital and intensive care unit length of stay. ONCABG resulted as an independent predictor of morbidity and mortality composite end-point. No statistically significant differences were observed in long-term all-cause mortality between groups.

The impact of off-pump surgery in end-organ function: practical end-points

Most surgeons perform coronary bypass surgery with the aid of cardiopulmonary bypass, which inflicts a massive systemic inflammatory response to the body leading to adverse clinical outcome. In an attempt to make CABG less invasive, interest have been diverted to the off pump technique.

The current review attempts to bring an insight onto the last ten years knowledge on the off-pump impact in end organ function, with an aim to draw some clear conclusions in order to allow practitioners to reflect on the subject.

Outcome Reporting in Cardiac Surgery Trials: Systematic Review and Critical Appraisal

Background

There is currently no accepted standard for reporting outcomes following cardiac surgery. The objective of this paper was to systematically review the literature to evaluate the current use and definition of perioperative outcomes reported in cardiac surgery trials.

Methods and Results

We reviewed 5 prominent medical and surgical journals on Medline from January 1, 2010, to June 30, 2014, for randomized controlled trials involving coronary artery bypass grafting and/or valve surgery. We identified 34 trials meeting inclusion criteria. Sample sizes ranged from 57 to 4752 participants (median 351). Composite end points were used as a primary outcome in 56% (n=19) of the randomized controlled trials and as a secondary outcome in 12% (n=4). There were 14 different composite end points. Mortality at any time (all-cause and/or cardiovascular) was reported as an individual end point or as part of a combined end point in 82% (n=28), myocardial infarction was reported in 68% (n=23), and bleeding was reported in 24% (n=8). Patient-centered outcomes, such as quality of life and functional classification, were reported in 29% (n=10). Definition of clinical events such as myocardial infarction, stroke, renal failure, and bleeding varied considerably among trials, particularly for postoperative myocardial infarction and bleeding, for which 8 different definitions were used for each.

Conclusions

Outcome reporting in the cardiac surgery literature is heterogeneous, and efforts should be made to standardize the outcomes reported and the definitions used to ascertain them. The development of standardizing outcome reporting is an essential step toward strengthening the process of evidence-based care in cardiac surgery.

Off-pump coronary artery bypass grafting improves short-term outcomes in high-risk patients compared with on-pump coronary artery bypass grafting: Meta-analysis

OBJECTIVES

To assess the benefits and risks of off-pump coronary artery bypass (OPCAB) versus coronary artery bypass grafting (CABG) through a meta-analysis of randomized controlled trials (RCTs), and to investigate the relationship between outcomes and patient risk profile.

METHODS

PubMed, Embase, the Cumulative Index of Nursing and Allied Health Literature, Scopus, Web of Science, Cochrane Library, and major conference proceedings databases were searched for RCTs comparing OPCAB and CABG and reporting short-term (≤ 30 days) outcomes. Endpoints assessed were all-cause mortality, myocardial infarction (MI), and cerebral stroke.

RESULTS

The meta-analysis included 100 studies, with a total of 19,192 subjects. There was no difference between the 2 techniques with respect to all-cause mortality and MI (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.71-1.09; P = .25; I(2) = 0% and OR, 0.90; 95% CI, 0.77-1.05; P = .19; I(2) = 0%, respectively). OPCAB was associated with a significant 28% reduction in the odds of cerebral stroke (OR, 0.72; 95% CI, 0.56-0.92; P = .009; I(2) = 0%). A significant relationship between patient risk profile and benefits from OPCAB was found in terms of all-cause mortality (P < .01), MI (P < .01), and cerebral stroke (P < .01).

CONCLUSIONS

OPCAB is associated with a significant reduction in the odds of cerebral stroke compared with conventional CABG. In addition, benefits of OPCAB in terms of death, MI, and cerebral stroke are significantly related to patient risk profile, suggesting that OPCAB should be strongly considered in high-risk patients.

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.

Evaluation of brain lesions in patients after coronary artery bypass grafting using MRI with the emphasis on susceptibility-weighted imaging

Introduction

Patients undergoing coronary artery bypass grafting (CABG) are at risk of strokes and neurocognitive disorders.

The aim of the study

The aim of the study was to assess the clinical utility of susceptibility-weighted imaging (SWI) MRI in detection of new brain lesions in patients after CABG. We assessed the incidence and types of brain lesions and correlated the data with neurological examinations in groups of patients who underwent on-pump and off-pump CABG.

Material and methods

Patients underwent a neurological examination and MRI before, 6-20 days after and 6 months after the CABG. Fifty-one patients (43 men, mean age 63.12 years) were analyzed.

Results

Fifteen (29.4%) patients underwent on-pump CABG, 36 (70.6%) off-pump CABG. On postoperative scans new lesions were detected in 12 (23.5%) patients. Ischemic lesions (visible on diffusion-weighted imaging [DWI]) were detected in 4 patients, in 6 lesions were visible on SWI, in 1 case lesions were visible on SWI and DWI. Hemorrhagic stroke was observed in 1 patient. In the group of patients who underwent on-pump CABG, new brain lesions were observed in 60.0% of patients vs. 8.3% of those who underwent off-pump CABG (p < 0.0001); these changes more frequently were multiple (p < 0.0013) and located infratentorially (p < 0.0218). Lesions visible on SWI were observed only in patients undergoing on-pump CABG (p = 0.00005). In all patients (except for 1 with stroke), lesions visible in MRI were clinically silent.

Conclusions

The use of SWI enables one to detect lesions occurring in the brain after CABG, invisible in other sequences. On-pump CABG is associated with a greater risk of clinically silent brain damage compared to off-pump CABG.