Off-pump coronary artery bypass graft surgery in California, 2003 to 2005

Off-Pump Coronary Artery Bypass Grafting; is it Still Relevant?

Off-pump Coronary Artery Bypass Grafting (OPCAB) experienced a resurgence in the 1980s -2000s and developed steadily with improvement of the instrumentation and techniques. However questions about graft patency and long-term survival of OPCAB patients still exist. This review attempts to explore the current relevance of OPCAB.

Effect of Hospital and Surgeon Procedure Volumes on the Incidence of Intraoperative Conversion During Off-Pump Coronary Artery Bypass Grafting

Intraoperative conversion to cardiopulmonary bypass with its subsequent high mortality is a major concern associated with off-pump coronary artery bypass grafting (OPCAB). The impact of procedure volume on the incidence of intraoperative conversion, however, is poorly defined. This study therefore evaluated the effect of procedure volume on the incidence of conversion in OPCAB using nationwide data. We analyzed 31,361 patients who underwent primary, nonemergent, isolated OPCAB during 2013-2016 reported in the Japan Cardiovascular Surgery Database. Hospitals (n = 548) and surgeons (n = 1315) were divided into tertile categories (low-, medium-, and high volumes) based on the total number of isolated coronary artery bypass grafting (CABG). Hierarchical logistic regression analysis, including 22 preoperative factors and hospital and surgeon CABG volumes, was used to assess the relation between procedure volume and the risk of conversion due to bleeding/hemodynamic instability. There were 797 (2.5%) intraoperative conversions due to bleeding/hemodynamic instability. Risk-adjusted odds ratios for conversion were significantly lower in some combined hospital/surgeon CABG volume categories than in the reference category. Hospital/surgeon volumes and their odds ratio (95% confidence interval) were as follows: low/low 1.00 (reference); medium/low 0.62 (0.39-0.96); high/low 0.47 (0.27-0.81); high/high 0.58 (0.38-0.89). There was a lower risk of conversion in medium- and high-volume than low-volume hospitals, especially among low-volume surgeons. Procedure volume is associated with the incidence of conversion during OPCAB. Among low-volume surgeons, hospital CABG volume significantly reduces conversion in a volume-dependent manner. These findings will be useful for safety training of OPCAB surgeons.

Cardiovascular Risk Factors in Coronary Artery Bypass Graft Patients: Comparison Between Two Periods

Background

Information showing risk factor trends in patients undergoing coronary artery bypass graft in Saudi Arabia is scarce. Thus, we aimed to compare cardiovascular risk factors among coronary artery bypass graft patients between two periods: 2012 and 2018.

Methods

This was a cross-sectional study based on hospital records at a tertiary center in Saudi Arabia. The medical records of 72 patients in 2012 and 111 patients in 2018 were reviewed. The study included all patients who underwent coronary artery bypass grafting for the first time. The chi-square test and independent t-test were used for statistical analysis; P-values less than 0.05 were considered statistically significant.

Results

The mean (SD) of the patient age was 61.21 (9.74) years in the first period and 58.01 (11.14) years in the second period. The number of patients who smoked was significantly higher in the second period of the study (14.3% in the first period; 27.0% in the second period; P < 0.001). The study also showed an increase in hypertension and diabetes mellitus in the second period compared to the first (70% vs 71.2% and 68.6% vs 72.1%, respectively), and a reduction in the percentage of patients with hypercholesterolemia (18.3% vs 17.1%). However, these findings were non-significant.

Conclusions

The percentage of smokers was significantly higher in the second period of this research as a consequence of cultural variation and because of the popularity of water-pipe smoking in the society. We recommend the need for increased awareness regarding smoking and the implementation of smoking-cessation programs.

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.

Myocardial revascularization without extracorporeal circulation; Why hasn't it convinced yet?

Extracorporeal circulation has led to a great development in cardiovascular surgery during the last five decades. Its time-proven efficacy and safety have made on-pump coronary artery bypass grafting (CABG) the gold standard method of surgical revascularization. However, coronary revascularization on cardiopulmonary bypass and the accompanying aortic manipulation are related to plenty of deleterious complications. Therefore, off-pump CABG surgery was established to avoid complications. Nevertheless, despite the initial enthusiasm on this technique, only 20% of myocardial revascularization procedures worldwide are performed off-pump. Not only are off-pump cardiac procedures more technically difficult but also they do not provide better results in terms of graft patency, completeness of revascularization, repeat revascularization requirement, cost, and quality of life. Completeness of revascularization and anastomotic quality should not be compromised to avoid cardiopulmonary bypass.

The future of off-pump coronary artery bypass grafting: a North American perspective

Off-pump coronary artery bypass graft (OPCAB) is currently performed routinely in a minority of specialized centers and in many more centers, utilized only when a porcelain aorta mandates a no-touch aortic technique. The OPCAB literature can be summarized as follows: (I) large-scale randomized trials in relatively low risk patients that include surgeons with a range of experience demonstrating no consistent beneficial differences in major cardiovascular and cerebrovascular outcomes but lower transfusion rates and shorter length of stay, tempered by some reports of higher rates of incomplete revascularization and lower rates of long term graft patency; (II) smaller randomized controlled trials (RCTs) from highly specialized programs demonstrating equivalent or superior outcomes with OPCAB and similar completeness of revascularization and graft patency; and (III) observational data from large databases demonstrating a consistent benefit of OPCAB, especially in higher-risk patient subsets. Our rationale for OPCAB remains that if complete and precise revascularization can be safely and routinely accomplished, then the patient should benefit by avoiding the morbidities that can be attributed to aortic cannulation/clamping, cardiopulmonary bypass (CPB), hemodilution, hypothermia and global myocardial ischemia/cardioplegia. We further believe that OPCAB procedures should emphasize the use of arterial grafts to optimize long term patency and minimize aortic manipulation to limit the risk of stroke. Moving forward, the off-pump surgical community and specialty societies must address the challenge of training surgeons and their teams to master this technically demanding procedure. Furthermore, OPCAB opens the door to minimally-invasive surgical revascularization via hybrid coronary revascularization (HCR). A large NIH-funded RCT is currently underway to determine whether hybrid revascularization can offer a superior alternative to multi-vessel percutaneous coronary intervention for patients with low SYNTAX score and proximal LAD disease.

Current outcomes of off-pump coronary artery bypass grafting: evidence from real world practice

Coronary artery bypass grafting (CABG) can be performed conventionally using cardiopulmonary bypass (CPB) and aortic clamping or on a beating heart (BH) without the use of CPB, the so-called off-pump CABG. Some surgeons, who are proponents of off-pump CABG, preferentially use this technique for the majority of operations, whereas others use it only in certain situations which warrant avoidance of CPB. Ever since the conception of off-pump CABG, the never-ending debate about which technique of CABG is safe and efficacious continues to date. Several randomized controlled trials (RCTs) have been conducted that have either favored on-pump CABG or have failed to show a significant difference in outcomes between the two techniques. However, these RCTs have been fraught with claims that they do not represent the majority of patients undergoing CABG in real world practice. Therefore, assessment of the benefits and drawbacks of each technique through observational and registry studies would be more representative of patients encountered in daily practice. The present review examines various retrospective studies and meta-analyses of observational studies that compare the early and long-term outcomes of off- and on-pump CABG, which assesses their safety and efficacy. Additionally, their outcomes in older patients, females, and those with diabetes mellitus, renal dysfunction, presence of ascending aortic disease, and/or acute coronary syndrome (ACS) have also been discussed separately. The general consensus is that early results of off-pump CABG are comparable to or in some cases better than on-pump CABG. However, on-pump CABG provides a survival benefit in the long term according to a majority of publications in literature.

Role of Left Main Coronary Artery Stenosis on Intraoperative Conversion and Mortality in Off-Pump Coronary Artery Bypass

BACKGROUND

Intraoperative conversion is a major threat in off-pump coronary artery bypass (OPCAB). The conversion rate depends on patient selection and surgeon experience. Previous studies have demonstrated the feasibility of OPCAB for patients with left main coronary artery stenosis (LMCAS) ≥ 50%. However, no studies have focused on the role of LMCAS ≥ 90%. We sought to assess the impact of LMCAS ≥ 90% on the conversion rate and mortality in OPCAB.

METHODS

We conducted a retrospective review of 1055 consecutive unselected patients undergoing OPCAB between 2000 and 2012. The patients in our study were divided into 3 groups by the severity of LMCAS.

RESULTS

LMCAS was < 50% in 704, 50-90% in 266, and ≥ 90% in 85 patients. LMCAS was not associated with major postoperative complications and hospital mortality, although preoperative cardiogenic shock was present in 6.3%. Overall, the conversion rate was 10.1%:11.4% in LMCAS < 50%, 5.6% in LMCAS 50-90%, and 14.1% in LMCAS ≥ 90%. Operation status, cardiogenic shock, left ventricular ejection fraction < 30% and operation before 2007 were noted as independent predictors of conversion. The overall hospital mortality rate was 5.1%: 4.8% in LMCAS < 50%, 4.5% in LMCAS 50-90%, and 9.4% in LMCAS ≥ 90%. Operation status, cardiogenic shock, left ventricular ejection fraction < 30% and intraoperative conversion were observed to be independent predictors of mortality. However, LMCAS did not predict either conversion or hospital mortality.

CONCLUSIONS

LMCAS ≥ 90% was not an independent predictor of intraoperative conversion or hospital mortality in OPCAB.

KEY WORDS

Conversion; Left main coronary artery stenosis; Off-pump coronary artery bypass.

On-pump versus off-pump coronary artery bypass graft surgery: what do the evidence show?

The main purpose of the off-pump coronary artery bypass surgery is to reduce morbidity and mortality due cardiopulmonary bypass. However, even though many studies have shown that off-pump coronary artery bypass is feasible and provides hospital morbidity and mortality similar to the on-pump coronary artery bypass graft surgery, probably better in some aspects, its long-term results have been questioned, since some trials have shown reduced survival with off-pump coronary artery bypass. It is likely that incomplete revascularization and/or poor graft patency with off-pump coronary artery bypass probably are responsible for such unfavorable outcome.

Perioperative outcomes after on- and off-pump coronary artery bypass grafting

Although numerous reports describe the results of off-pump coronary artery bypass grafting (CABG) at specialized centers and in select patient populations, it remains unclear how off-pump CABG affects real-world patient outcomes. We conducted a large, multicenter observational cohort study of perioperative death and morbidity in on-pump (ON) versus off-pump (OFF) CABG. We reviewed Veterans Affairs Surgical Quality Improvement Program data for all patients (N=65,097) who underwent isolated CABG from October 1997 through April 2011 (intention-to-treat data were available from 2005 onward). The primary outcome was perioperative (30-day or in-hospital) death; the secondary outcomes were perioperative stroke, dialysis dependence, reoperation for bleeding, mechanical circulatory support, myocardial infarction, ventilator support ≥ 48 hr, and mediastinitis. Propensity scores calculated from age, 17 preoperative risk factors, and year of surgery were used to match 8,911 OFF with 26,733 ON patients. In the complete cohort, compared with the ON patients (n=53,468), the OFF patients (n=11,629) had less perioperative death (2.02% vs 2.53%, P=0.0012) and lower incidences of all morbidities except perioperative myocardial infarction. In the matched cohort, perioperative death did not differ significantly between OFF and ON patients (1.94% vs 2.28%, P=0.06), but the OFF group had lower incidences of all morbidities except for perioperative myocardial infarction and mediastinitis. A subgroup intention-to-treat analysis yielded similar but smaller outcome differences between the ON and OFF groups. Off-pump CABG might be associated with decreased operative morbidity but did not affect operative death, compared with on-pump CABG. Future studies should examine the effect of off-pump CABG on long-term outcomes.

Off-pump coronary artery bypass grafting--the current state

The optimal strategy for coronary revascularization remains controversial. Currently, most surgical revascularizations are performed with the use of cardiopulmonary bypass (ONCAB), yet over the past 20 years off-pump coronary artery bypass grafting (OPCAB) has been increasingly used because of the increased awareness of the deleterious effects of cardiopulmonary bypass (CPB) and aortic manipulation. Small, prospective, randomized controlled trials have lacked sufficient sample size to demonstrate differences in early and long-term outcomes. Larger observational studies that are better powered to statistically compare outcomes have shown more favorable in-hospital outcomes and equivalent long-term outcomes with OPCAB and ONCAB. The benefits of OPCAB techniques may be more apparent for patients at high risk for complications associated with CPB and aortic manipulation. Recent studies have demonstrated improved outcomes in higher-risk patients undergoing OPCAB, as well as improved neurological outcomes. The purpose of this review is to outline the recent literature comparing OPCAB with ONCAB, and to demonstrate efficacy of OPCAB as a useful technique for coronary revascularization.

Coronary revascularization trends in the United States, 2001-2008

CONTEXT

Coronary revascularization is among the most common hospital-based major interventional procedures performed in the United States. It is uncertain how new revascularization technologies, new clinical evidence from trials, and updated clinical guidelines have influenced the volume and distribution of coronary revascularizations over the past decade.

OBJECTIVE

To examine national time trends in the rates and types of coronary revascularizations.

DESIGN, SETTING, AND PATIENTS

A serial cross-sectional study with time trends of patients undergoing coronary artery bypass graft (CABG) surgery or percutaneous coronary interventions (PCIs) between 2001 and 2008 at US hospitals in the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample, which reports inpatient coronary revascularizations. These data were supplemented by Medicare outpatient hospital claims.

MAIN OUTCOME MEASURES

Annual procedure rates of coronary revascularizations, CABG surgery, and PCI.

RESULTS

A 15% decrease (P < .001) in the annual rate of coronary revascularizations was observed from 2001-2002 to 2007-2008. The annual CABG surgery rate decreased steadily from 1742 (95% confidence interval [CI], 1663-1825) CABG surgeries per million adults per year in 2001-2002 to 1081 (95% CI, 1032-1133) CABG surgeries per million adults per year in 2007-2008 (P < .001), but PCI rates did not significantly change (3827 [95% CI, 3578-4092] PCI per million adults per year in 2001-2002 vs 3667 [95% CI, 3429-3922] PCI per million adults per year in 2007-2008, P = .74). Between 2001 and 2008, the number of hospitals in the Nationwide Inpatient Sample providing CABG surgery increased by 12% (212 in 2001 vs 241 in 2008, P = .03), and the number of PCI hospitals increased by 26% (246 in 2001 vs 331 in 2008, P < .001). The median CABG surgery caseload per hospital decreased by 28% (median [interquartile range], 253 [161-458] in 2001 vs 183 [98-292] in 2008; P < .001) and the number of CABG surgery hospitals providing fewer than 100 CABG surgeries per year increased from 23 (11%) in 2001 to 62 (26%) in 2008 (P < .001).

CONCLUSIONS

In US hospitals between 2001 and 2008, a substantial decrease in CABG surgery utilization rates was observed, but PCI utilization rates remained unchanged.

Teaching off-pump coronary artery bypass surgery

Off-pump coronary artery revascularization requires a unique skill set and a different conduct of operation compared with on-pump coronary artery bypass. Not only must the surgeon perform anastomoses on the beating heart, but he/she must understand the hemodynamic consequences of cardiac positioning and stabilization, the effects of regional ischemia on hemodynamic function, contractility, and arrhythmias, and the importance of anesthesia and grafting sequence given variants of anatomy and clinical conditions. Given these differences, the ability to teach off-pump coronary artery bypass to residents and surgeons places unique demands on the teaching surgeon. In this article, we review the available literature about the safety and efficacy of teaching off-pump coronary artery bypass to residents, discuss the fundamentals for training residents, and review the future of simulation and new training paradigms and the impact this will have on current training methods.

Percutaneous treatment with drug-eluting stent vs bypass surgery in patients suffering from chronic stable angina with multivessel disease involving significant proximal stenosis in left anterior descending artery

BACKGROUND

The aim of the present study was to compare the effects of drug-eluting stents (DES) and coronary artery bypass grafting (CABG) in patients suffering from chronic stable angina with multivessel disease, involving significant proximal stenosis in the left anterior descending artery (LAD).

METHODS AND RESULTS

All consecutive patients suffering from chronic stable angina with multivessel disease involving significant proximal LAD stenosis underwent DES implantation (n=600) or CABG (n=709) at our institution. At 2 years, the unadjusted mortality was significantly lower in the DES group than in the CABG group (2.2% vs 5.2%, P=0.004), but the adjusted risk of death was similar (odds ratio (OR) 0.74, 95%CI 0.28-1.97, P=0.555). Furthermore, both the adjusted rate of nonfatal myocardial infarction and cerebrovascular events was also comparable. However, the unadjusted and adjusted risk of major adverse cardiac cerebrovascular events in the DES was significantly higher than in the CABG (13.3% vs 9.6%, OR 2.71, 95%CI 1.56-4.74, P<0.001), which is probably attributed to the higher subsequent revascularization rate after DES implantation.

CONCLUSIONS

DES showed comparable long-term mortality for the treatment of multivessel disease involving significant proximal stenosis in LAD in comparison with CABG.

[Not Available]

Aim:

We aimed to report our postoperative results in elderly patients that had off-pump coronary bypass grafting.

Method:

Data of 173 patients with isolated coronary bypass 70 years of age or older were retrospectively evaluated. One month follow-up data were evaluated in all patients. After getting verbal informed consent a total of 91 patients were included in the quality of life assessment via EuroQoL form. The data of patients with age of 70-74 and 75 or older were compared.

Results:

The mean ages of patients at age of 70-74 and ≥75 were 71.69±0.16 and 76.81±0.23 years; respectively. Eleven cases had in-hospital mortality (%6 of 173 patients). The mean follow-up period for the group that were reached for EuroQoL assessment was 46,3 ± 20,8 months. The percent of cases among the whole study group that had participated in the quality of life questionnaire were in good condition in terms of mobility, self-care, usual activities, pain/discomfort, anxiety/depression were %75, %87, %81, %92 and %89; respectively.

Discussion:

Off-pump coronary bypass operation may be safely used in elderly patients with high quality of life and low morbidity and mortality.