Off-pump coronary surgery: effect on early mortality and stroke

Aortic Arch Atheroma: Stroke Reduction in Cardiac Surgical Patients

Cardiac surgery is increasingly performed on elderly patients with extensive coronary artery abnormalities who have impaired left ventricular function, decreased physiologic reserve, and multiple comorbid conditions. Considerable numbers of these patients develop perioperative neurologic complications ranging from subtle cognitive dysfunction to more evident postoperative confusion, delirium, and, less commonly, clinically apparent stroke. Magnetic resonance imaging studies have elucidated that a considerable number of patients have new ischemic brain infarcts, particularly after conventional coronary artery bypass graft surgery. Mechanisms of cerebral injury during and after cardiac surgery are discussed. Intraoperative transesophageal echocardiography and epiaortic scanning for detection of atheromatous disease of the proximal thoracic aorta is paramount in identifying patients at high risk from neurologic injury. It is important to recognize that our efforts to minimize neurologic injury should not be limited to the intraoperative period. Particular efforts should be directed to temperature management, glycemia control, and pharmacologic neuroprotection extending into the postoperative period. Preoperative magnetic resonance angiography may be of value for screening patients with significant atheroma of the proximal thoracic aorta. It is likely that for patients with no significant atheromatous disease, conventional coronary artery revascularization is the most effective long-term strategy, whereas patients with atheromatous thoracic aorta may be better managed with beating heart surgery, hybrid techniques, or medical therapy alone. Patient stratification based on the aortic atheromatic burden should be addressed in future trials designed to tailor treatment strategies to improve long-term outcomes of coronary heart disease and reduce the risks of perioperative neurologic injury.

Long-term Outcomes after Off-Pump or Conventional Coronary Artery Bypass Grafting within a Veteran Population

Objective

Recently published data indicate that outcomes for off-pump coronary artery bypass grafting (OPCABG) may be inferior to conventional CABG (cCABG) within the Veteran population, but this has been only partly addressed within high-volume off-pump centers. Here, we seek to examine the long-term outcomes for these patients within the Veteran population at a single institution well experienced with OPCABG.

Methods

With the use of a preexisting in-house database, all patients who had undergone isolated CABG from 2000 to 2011 (n = 1125) were identified. From these data, 18 demographic and risk factors were compared and used to create a propensity score, which was used for matching between groups (OPCABG vs cCABG). The primary end point examined was death. Survival was analyzed using the Kaplan-Meier method and the log-rank test. Groups were compared using a Student t test or Fisher exact test, where appropriate.

Results

Unmatched OPCABG and cCABG groups were found to have significant differences in risk factors, with the OPCABG being a higher-risk population by ejection fraction, chronic obstructive pulmonary disease status, age, and renal function, among others (all P < 0.05). Kaplan-Meier analysis of the unmatched groups demonstrated an increased mortality rate within the higher-risk OPCABG group ( P = 0.0002). With the use of propensity score matching, 337 OPCABG patients were then matched to 337 cCABG controls. Comparison of demographic and risk factors between these matched groups did not demonstrate any statistically significant difference. When Kaplan-Meier analysis was performed for the matched groups, there was no statistically significant difference in survival. In addition, in the matched data set, OPCABG patients had a shorter average length of stay (8.2 vs 9.7 days, P = 0.022), shorter operative time (205 vs 270 minutes, P < 0.001), and lower rate of bleeding complications (0.9% vs 3.6%, P = 0.032).

Conclusions

In this high-volume off-pump center, matched OPCABG survival is similar to cCABG. Although recent data indicate that OPCABG survival may be worse than that of cCABG within the entire Veteran population, in centers well experienced with OPCABG, this does not seem to hold true. In addition, the benefit of decreased length of stay and lower morbidity rates seems to be significant. Further study of the long-term outcomes of OPCABG in high-volume Veteran's centers is warranted.

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.

Performing coronary artery bypass grafting off-pump may compromise long-term survival in a veteran population

BACKGROUND

There are ample data regarding the short-term outcomes of on-pump and off-pump coronary artery bypass grafting (CABG), but little is known about the long-term survival associated with these approaches.

METHODS

Using the Veterans Affairs (VA) Continuous Improvement in Cardiac Surgery Program, we identified all VA patients (n = 65,097) who underwent primary isolated CABG from October 1997 to April 2011. The primary outcome measure was all-cause mortality. Age, 17 preoperative risk factors, and year of operation were used to calculate propensity scores for each patient. A greedy-match algorithm using the propensity scores matched 8,911 off-pump with 26,733 on-pump patients. Survival functions were estimated by the Kaplan-Meier method and compared by using the log-rank test.

RESULTS

In the complete cohort, off-pump was used in 11,629 of 65,097 (17.9%) operations. For the matched cohort, the median follow-up was 6.7 years (interquartile range, 3.72 to 9.35 years). Risk-adjusted mortality did not differ significantly between the off-pump and on-pump groups at 1 year (4.67% vs 4.78%; risk ratio [RR], 0.98; 95% confidence interval [CI], 0.88 to 1.09) or 3 years (9.21% vs 8.89%; RR, 1.04; 95% CI, 0.96 to 1.12). However, risk-adjusted mortality was higher in the off-pump group at 5 years (14.47% vs 13.45%; RR, 1.08; 95% CI 1.02 to 1.15) and 10 years (25.18% vs 23.57%; RR, 1.07; 95% CI, 1.03 to 1.12). Overall, the hazard ratio for off-pump vs on-pump was 1.06 (95% CI, 1.00 to 1.13; p = 0.04).

CONCLUSIONS

Off-pump CABG may be associated with decreased long-term survival. Further studies are needed to identify the reasons behind this finding.

Changing strategy for aortic stenosis with coronary artery disease by transcatheter aortic valve implantation

Coronary artery disease (CAD) is combined with aortic stenosis (AS) in 40-50 % of patients with typical angina. Recently, transcatheter aortic valve implantation (TAVI) has changed the guideline for AS in patients with high comorbidity. At the same time more than 60 % of isolated CABG has been performed without cardiopulmonary bypass in Japan. CABG is recommended and should be considered in patients with primary indication for AVR and luminal stenosis >70 % in major coronary arteries and the left internal thoracic artery (LITA) by guidelines. AVR is indicated for severe AS undergoing CABG. It is generally accepted to perform AVR for moderate AS at the time of CABG by valve guidelines. However, prophylactic AVR for moderate AS associated with CABG may increase the early operative risk and expose the patients to postoperative long-term valve related complications. AVR after previous CABG poses potential risk for mortality and morbidity. The presence of patent ITA is a significant risk of its injury and difficulty of myocardial protection during aortic cross-clamping. Therefore, at present, for severe AS previous CABG with patent ITA should be one of the definite indications of TAVI. Rationale of TAVI in patients with severe AS and CAD has not been clearly delineated. The safety of TAVI irrespective of the extent and anatomy of CAD is still controversial. PCI is not appropriate before TAVI in high-risk patients with CAD. In the near future hybrid TAVI will be realistic considering least operative mortality and morbidity in high-risk patients.

Left anterior descending artery revascularization in low-risk patients: early outcomes after off-pump versus on-pump surgery

BACKGROUND AND AIM OF THE STUDY

This study aimed to compare the early outcomes of off-pump and on-pump myocardial revascularization in patients with stenosis in the left anterior descending artery (alone or with diagonal artery disease).

METHODS

We retrospectively reviewed the medical records of 300 patients: 150 who underwent on-pump coronary artery bypass and 150 who underwent off-pump coronary artery bypass grafting. There were no significant differences between the 2 groups with respect to medical data and operative findings. On-pump and off-pump groups were compared in terms of mortality and morbidity within 30 days of the operation.

RESULTS

Hospital mortality was 3.3% (5 patients) in the on-pump group and 2.6% (4 patients) in the off-pump group. Five patients (3.3%) in the on-pump group experienced myocardial infarction; 3 died of cardiogenic shock. Four patients (2.6%) in the off-pump group experienced myocardial infarction, and 2 of these patients died. Two patients (1.3%) in the on-pump group and 2 patients (1.3%) in the off-pump group experienced stroke; 1 patient in each group died. One patient (0.6%) in the on-pump group had mediastinitis and died of sepsis.

CONCLUSIONS

Among low-risk patients (defined according to EuroSCORE criteria) who underwent left anterior descending coronary artery bypass, the results obtained with the on-pump and off-pump methods showed no significant differences with respect to morbidity or mortality.

Off-pump versus on-pump coronary artery bypass surgery in patients aged 80 years and older: institutional results and meta-analysis

Patients aged ≥80 years are at high risk of adverse events after coronary artery bypass grafting. This study was performed to evaluate whether off-pump coronary artery bypass surgery (OPCAB) is superior to conventional surgery (CCAB) in these high-risk patients. The outcome of 185 patients aged ≥80 years who underwent OPCAB or CCAB at our institution was reviewed and a meta-analysis on this issue was performed. Similar immediate postoperative results were observed after OPCAB and CCAB at our institution, despite significantly different operative risk (mean logistic EuroSCORE, OPCAB 20.3% vs CCAB 13.4%, P = 0.003). Among 56 propensity score matched pairs a trend toward lower postoperative stroke (0%, 95% CI 0-0 vs 3.6%, 95% CI 0-10.0, P = 0.50) was observed after OPCAB. No significant differences were observed in the other outcome end points. Five-year survival was 81.0% after OPCAB and 78.1% after CCAB (P = 0.239). Pooled analysis of eight studies including 3416 patients showed a significantly higher risk of postoperative stroke after CCAB (pooled rates: 4.2%, 95% confidence interval (95% CI) 2.4-7.1 vs 1.5%, 95% CI 0.9-2.5, risk ratio (RR) 2.15, 95% CI 1.17-3.96, P = 0.01). A trend toward higher immediate postoperative mortality was observed after CCAB (15 studies including 4409 patients, pooled rates: 6.5%, 95% CI 5.2-8.0 vs 5.6%, 95% CI 4.2-7.4, RR 1.29, 95% CI 0.86-1.93, P = 0.21). Generic inverse variance analysis showed similar intermediate survival after CCAB and OPCAB (RR 1.31, 95% CI 0.85-2.01, P = 0.22). At 2 years, survival was 82.8% (95% CI 76.4-89.2) after CCAB and 88.3% (95% CI 82.9-93.7) after OPCAB. Current results indicate that OPCAB compared with CCAB in patients aged ≥80 years is associated with significantly lower postoperative stroke and with a trend toward better early survival. However, suboptimal quality of the available studies, particularly the lack of comparability of the study groups, prevents conclusive results on this controversial issue.

Minimizing the risk of perioperative stroke by clampless off-pump bypass surgery: a retrospective observational analysis

Objectives

Stroke is a devastating complication after coronary artery bypass grafting, occurring in 1.4% to 4.3% of patients. A major cause of stroke is cerebral embolization of aortic atheromatous debris or calcified plaques. This report analyzes the incidence of stroke in patients treated according to the clampless concept, i.e. avoiding side-clamping of the aorta, by means of off-pump coronary artery bypass surgery (OPCAB) in combination with the HEARTSTRING device.

Methods

During a period of 43 months (2005-2008), 412 consecutive patients were treated with the above-mentioned method by one single surgeon. A minimum of one proximal aortal anastomosis was performed in each patient. Altogether, 542 proximal anastomosis were applied, each created by means of the HEARTSTRING device.

Results

The mean age of patients was 67+9.7 years, the predicted mortality 5.2% (logistic EuroSCORE) and the observed mortality 1.9%. Histories of preoperative neurological disorders or cerebrovascular diseases were documented in 15% of patients. The overall incidence of postoperative stroke was 0.48% in contrast to 1.3% according to the stroke risk score.

Conclusions

In accordance to previously published data, our results show that avoiding aortic side-clamping during OPCAB reduces postoperative stroke rates. The HEARTSTRING device is a safe option for creating proximal aortic anastomosis.

Comparison of bypass surgery with drug‐eluting stents for diabetic patients with multivessel disease

BACKGROUND

This retrospective study of prospectively collected data compared coronary artery bypass graft (CABG) surgery to drug-eluting stenting (DES) in diabetic patients with multivessel coronary artery disease (CAD). Prior randomized trials and clinical studies have suggested that CABG may be the preferred revascularization strategy in diabetic patients with multivessel CAD. Data are limited regarding the impact of DES vs. CABG on clinical outcomes.

METHODS

We included 205 consecutive diabetic patients who underwent either CABG (n=103) or DES (n=102). The primary clinical end points were freedom from major adverse cardiac events (MACE) at 30 days and 1 year.

RESULTS

Baseline characteristics were similar between both groups. At 1 year, the mortality rate was similar in the CABG and DES group (8% vs. 10%, p=0.6) but the MACE rate was lower in the CABG group (12% vs. 27%, p=0.006) due to less repeat revascularization with CABG (3% vs. 20%, p<0.001). Stroke occurred only in the CABG group (4% vs. 0%, p=0.04). Angiographically-documented stent thrombosis after DES occurred in 3%. Presentation with acute myocardial infarction (hazard ratio [HR], 2.26, 95% CI, 1.13 to 4.55) and DES (HR, 2.4, 95% CI, 1.23 to 4.77) were positive independent predictors, whereas therapy with a statin was a negative independent predictor of MACE (HR, 0.40, 95% CI, 0.21 to 0.76).

CONCLUSIONS

Bypass surgery was associated with less MACE primarily due to the higher repeat revascularization rate with DES and is therefore superior to DES despite more extensive CAD in CABG patients.

Predictors of Early Postoperative Cerebral Infarction After Isolated Off-Pump Coronary Artery Bypass Grafting

BACKGROUND

Risk factors associated with cerebral infarction within 7 days after off-pump coronary artery bypass grafting require further statistical elucidation.

METHODS

From January 1997 to July 2006, off-pump coronary artery bypass grafting was performed in 576 patients at Toyama University Hospital. Factors including previous cerebral infarction, lesions in head and neck vessels, preoperative cerebral ischemic symptoms, intraaortic balloon pump use, number of coronary lesions, number of coronary bypasses, sites of coronary bypasses, number of proximal anastomoses in the ascending aorta, use of aortic no-touch procedure, partial aortic clamping, automatic proximal anastomosis devices, and a proximal seal system were compared retrospectively between patients with and without early cerebral infarction. Factors differing between groups were analyzed further by multivariate logistic regression.

RESULTS

Ten patients (1.7%) had cerebral infarction within 7 days after surgery. The subjects were divided into two groups, those who had cerebral infarction after surgery (n = 10) and those who did not (n = 566). Factors showing significant intergroup differences were a previous history of cerebral infarction (p < 0.001), preoperative presence of cerebral ischemic symptoms (p < 0.001), vascular lesions in head and neck vessels (p < 0.001), use of partial aortic clamping (p = 0.002), and postoperative atrial fibrillation within 7 days after surgery (p = 0.011). Multiple logistic regression analysis indicated close relationships between previous history of cerebral infarction (odds ratio, 26.6; 95% confidence interval, 2.8 to 251.1; p = 0.004), preoperative presence of cerebral ischemic symptoms plus lesions in head and neck vessels (odds ratio, 22.8; 95% confidence interval 1.8 to 285.7; p = 0.015), and use of partial aortic clamping (odds ratio, 11.1; 95% confidence interval, 1.4 to 85.7; p = 0.021). Postoperative atrial fibrillation within 7 days after surgery (odds ratio, 3.4; 95% confidence interval, 0.7 to 16.5; p = 0.121) was suspected as a risk factor for postoperative cerebral infarction.

CONCLUSIONS

Multivariate analysis identified independent factors strongly associated with cerebral infarction after off-pump coronary artery bypass grafting, such as partial aortic clamping, presence of cerebral ischemic symptoms plus head and neck vascular lesions, and previous cerebral infarction.

Myocardial Revascularization in Patients with Low Ejection Fraction <=35%: Effect of Pump Technique on Early Morbidity and Mortality

BACKGROUND AND AIM

Left ventricular dysfunction is an important predictor of in-hospital mortality. Surgical risk among these patients remains high. The present study is conducted to evaluate the difference in early morbidity and mortality among patients with compromised left ventricular function (LVF) after myocardial revascularization using either off-pump or on-pump coronary artery bypass graft.

METHODS

Between April 2000 and April 2004, 150 patients with ejection fraction (EF) < or =35% underwent isolated coronary artery bypass grafting. Eighty-four patients underwent conventional bypass (mean EF 30.1%+/- 4.2) and 66 patients had off-pump coronary artery bypass (mean EF 27.5%+/- 5.5). Different variables (preoperative, intraoperative, and postoperative) were evaluated and compared. Determination of operation risk was done using EuroSCORE. Patients who underwent OPCAB were more risky due to a high percentage of associated comorbidities, mean EuroSCORE was 12.96 +/- 13.21 in comparison to 8.47 +/- 10.22 in CCAB.

RESULTS

The mean operative mortality was 8.7%. Patients who underwent OPCAB had a lower operative mortality than CCAB (6.1% vs. 10.7%) inspite of a higher preoperative predicted risk score. Completeness of revascularization was higher among the CCAB group (85.7% vs. 69.7%; p = 0.01). Subsequently, the mean number of grafts was significantly higher among this group (3.4+/-0.7 vs. 2.0 +/-0.9; p < 0.001). On the other hand, morbidity was significantly higher in CCAB (35.7% vs. 19.7%; p = 0.03). However, the incidence of both myocardial infarction and atrial fibrillation was more among OPCAB.

CONCLUSIONS

Patients with left ventricular dysfunction are high-risk group. These patients can benefit from myocardial revascularization using either off-pump or conventional CABG, but both are associated with a higher mortality and morbidity than those with normal ventricle. The use of off-pump CABG resulted in better clinical outcome and mortality, but less number of grafts performed than those with conventional CABG especially in patients with lowest EF.

Off-Pump Coronary Artery Surgery for Reducing Mortality and Morbidity

OBJECTIVES

The purpose of this study was to assess the effects of off-pump coronary bypass surgery (OPCAB) on mortality and morbidity.

BACKGROUND

Despite its potential for reducing morbidity and mortality, OPCAB's role in clinical practice remains controversial.

METHODS

A meta-analysis of 37 randomized controlled trials (RCTs) (n = 3,449) and 22 risk-adjusted (logistic regression or propensity-score) observational studies (n = 293,617) was performed. Two reviewers performed literature searches (MEDLINE, EMBASE, PubMed, reference lists), quality assessment, and data extraction. Treatment effects were calculated as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

In RCTs, OPCAB was associated with reduced atrial fibrillation (OR 0.59; 95% CI 0.46 to 0.77) and trends toward reduced 30-day mortality (OR 0.91 95% CI 0.45 to 1.83), stroke (OR 0.52; 95% CI 0.25 to 1.05), and myocardial infarction (OR 0.79; 95% CI 0.50 to 1.25). Observational studies showed OPCAB to be associated with reduced 30-day mortality (OR 0.72; 95% CI 0.66 to 0.78), stroke (OR 0.62; 95% CI 0.55 to 0.69), infarction (OR 0.66; 95% CI 0.50 to 0.88), and atrial fibrillation (OR 0.78; 95% CI 0.74 to 0.82). At one to two years, OPCAB was associated with trends toward reduced mortality, but also increased repeat revascularization (RCT: OR 1.75, 95% CI 0.78 to 3.94; Observational: OR 1.35, 95% CI 0.76 to 2.39).

CONCLUSIONS

Randomized controlled trials did not find, aside from atrial fibrillation, the statistically significant reductions in short-term mortality and morbidity demonstrated by observational studies. These discrepancies might be due to differing patient-selection and study methodology. Future studies must focus on improving research methodology, recruiting high-risk patients, and collecting long-term data.

In the current era, complete revascularization improves survival after coronary artery bypass surgery

BACKGROUND

Complete revascularization has been the standard for coronary bypass grafting. However, surgical intervention has evolved with increasing use of arterial conduits and off-pump techniques.

METHODS

Patients undergoing non-redo bypass surgery from January 1998 through December 2000 were followed up with questionnaires and telephone contact. Incomplete revascularization was defined as absence of bypass grafts placed to a coronary territory supplied by a vessel with 50% or greater stenosis.

RESULTS

One thousand thirty-four patients were followed for a mean of 3.3 +/- 1.6 years. Complete revascularization was found in 937 (90.6%) patients, and incomplete revascularization was found in 97 (9.4%) patients. Eight hundred twenty-seven (80.4%) patients underwent on-pump operations, and 207 (19.6%) underwent off-pump operations. Incomplete revascularization was more prevalent in off-pump versus on-pump operations (21.7% vs 6.3%, P < .001). Multivariable Cox regression analysis indicated that in-hospital cerebrovascular accidents (hazard ratio, 5.49; P < .001), chronic obstructive pulmonary disease (hazard ratio, 1.97; P = .019), and incomplete revascularization (hazard ratio, 1.85; P = .040) predicted an increased hazard (risk) of cardiac death. Left internal thoracic artery (hazard ratio, 0.38; P = .047), right internal thoracic artery (hazard ratio, 0.25; P = .019), and radial artery (hazard ratio, 0.36; P < .001) grafting reduced the risk of cardiac death. The 5-year unadjusted survival rate was 52.6% versus 82.4% in patients undergoing incomplete and complete revascularization ( P < .001), with cardiac survival rates of 74.5% versus 93.1%, respectively ( P < .001). However, this difference in cardiac survival was smaller in octogenarians with incomplete versus complete revascularizations (77.4% vs 87.6%, P = .101) and was essentially absent in off-pump versus on-pump operations if complete revascularization was achieved in both cases (93.6% vs 93.1%, P > .200).

CONCLUSIONS

Complete revascularization and arterial grafting improve 5-year survival. Off-pump techniques do not affect survival. Complete revascularization should be performed whenever possible.

No-touch aorta off-pump coronary surgery: the effect on stroke

OBJECTIVE

Studies examining the neuroprotective effects of off-pump coronary artery bypass grafting have shown inconsistent results. Most studies, however, have not differentiated between clampless and clamp off-pump techniques. The aim of this study was to evaluate the effect of avoiding aortic manipulation on major neurologic outcomes after off-pump coronary artery bypass grafting.

METHODS

A total of 700 consecutive patients undergoing multiple-vessel off-pump coronary artery bypass grafting between 2000 and 2003 were included. The 429 patients undergoing aortic no-touch technique were compared with 271 patients in whom partial aortic clamps were applied. The aorta was screened by manual palpation, and epiaortic ultrasonography was used selectively.

RESULTS

The frequency of detected atherosclerotic aortic disease was higher in the no-touch group (17.4% vs 5.1%, P < .0001). No-touch revascularization was achieved with arterial conduits, arranged in T-graft or in situ configurations (50%). The respective graft/patient ratios were 2.5 +/- 0.6 and 2.6 +/- 0.6 in the side-clamp and no-touch groups ( P = .009); however, revascularization of the posterolateral myocardial territory was comparable (87% vs 90%, difference not significant). The incidence of stroke (0.2% vs 2.2%, P = .01) was significantly lower in the no-touch group (1/429). Logistic regression identified partial aortic clamping as the only independent predictor of stroke (odds ratio 28.5, confidence interval 0.22-333, P = .009), increasing this risk 28-fold. Peripheral vascular disease ( P = .068), diabetes ( P = .072), and history of stroke ( P = .074) trended toward stroke.

CONCLUSIONS

Avoiding partial aortic clamping during off-pump coronary artery bypass grafting provides superior neurologic outcome. The results are reproducible and irrespective of the severity of aortic disease or the method of aortic screening. This technique is recommended whenever technically feasible.

Total Arterial Off-Pump Coronary Artery Bypass Grafting for Revascularization of the Total Coronary System: Clinical Outcome and Angiographic Evaluation

BACKGROUND

We assessed the clinical outcome and conducted an angiographic study of total arterial off-pump coronary artery bypass grafting for revascularization of the total coronary system.

METHODS

Of 382 consecutive patients who underwent off-pump coronary artery bypass between April 2000 and December 2002, 235 patients (193 men and 42 women, mean age 66 +/- 9 years) with three-vessel disease underwent off-pump coronary artery bypass with all arterial grafts. A total of 872 vessels were bypassed (average number of grafts 3.7 +/- 0.8). The internal thoracic arteries, radial arteries, and gastroepiploic arteries were used for revascularization of 306, 542, and 24 coronary arteries, respectively. Two hundred twenty-five patients underwent revascularization with composite grafts that were connected to the in situ internal thoracic artery (Y configuration 181, I configuration 55, K configuration 27, X configuration 3, T configuration 1); 10 patients underwent revascularization with all in situ grafts.

RESULTS

Three (1.3%) hospital deaths and 1 late death occurred. There were no occurrences of clinical underperfusion syndrome or new intraaortic balloon pump insertion. Cerebral infarction occurred in 2 patients (0.8%). Early postoperative angiography was performed on 833 grafts in 223 patients (95%); the overall patency rate was 98%. Stratified by coronary distribution, the patency rate was 99% (218/221) in the left anterior descending artery, 97% (84/87) in the diagonal artery, 99% (70/71) in the obtuse marginal artery, 98% (262/268) in the posterolateral artery, 98% (167/170) in the posterior descending artery, and 100% (16/16) in the right coronary artery.

CONCLUSIONS

Total arterial off-pump coronary artery bypass yielded good clinical results and an excellent patency rate of revascularization for the total coronary system.

The Right Internal Thoracic Artery and Right Gastroepiploic Artery: Alternative Sites for Proximal Anastomosis in Patients with Atherosclerotic Calcified Aorta

BACKGROUND

Atherosclerotic or calcified ascending aorta is an important predictor of adverse cerebrovascular events. Using off-pump coronary artery bypass (OPCAB) with composite and in situ arterial grafting to avoid aortic manipulation and clamping may reduce the risk of stroke related to aortic atheroembolism. When the aorta is calcified and cannot serve as a safe site for proximal anastomosis, this anastomosis can be performed on the proximal segment of the right internal thoracic artery (ITA) and right gastroepiploic artery (RGEA). Four such cases are described.

METHODS

In 2 patients, the proximal right ITA was used as the site for proximal saphenous vein graft (SVG) anastomosis. Chronic obstructive lung disease in one patient and insulin-dependent diabetes in the other precluded performance of OPCAB with bilateral ITA. In addition, positive Allen test precluded performance of composite T-graft with radial artery (RA) on ITA. Both SVGs were anastomosed distally to the posterior descending artery. In 2 other patients, RA was connected end-to-side to the proximal segment of the RGEA. Both of these patients had repeat operations. The distal end of the RGEA was too small, and concerns regarding the future flow to a very large coronary bed precluded its use as an in situ graft.

RESULTS

All patients underwent the operative procedures without any neurological or cardiovascular adverse effects, and all are midterm, symptom-free survivors. Postoperative graft patency was confirmed intraoperatively with flow measurements and postoperatively with control angiography or coronary imaging computed tomography.

CONCLUSIONS

The RITA and proximal RGEA can serve safely as sites for proximal anastomosis in patients with atherosclerotic calcified aorta undergoing OPCAB.

Does off-pump total arterial grafting increase the incidence of intraoperative graft failure?

BACKGROUND

Early graft failure is a common cause of cardiac mortality and morbidity after coronary artery bypass grafting, but there is little information on its natural incidence. Furthermore, there is particular concern about graft patency in off-pump coronary artery bypass grafting and total arterial grafting.

METHODS

We performed a prospective observational study to assess intraoperative graft patency in patients undergoing off-pump and on-pump coronary artery bypass grafting, who also underwent total arterial grafting. We used an intraoperative imaging system, SPY (Novadaq Technologies Inc), based on the fluorescent properties of indocyanine green dye.

RESULTS

We assessed the intraoperative graft patency of 533 conduits in 200 patients. The mean number of grafts was 2.7 per patient. Of these patients, 155 (78%) had off-pump coronary artery bypass grafting, and 45 (22%) had on-pump coronary artery bypass grafting. Overall, 161 (80%) had total arterial grafting, with composite arterial grafting performed in 120 (60%) patients. Fluorescence, confirming graft patency, was observed in all but 8 (1.5%) conduits in 8 (4%) patients, necessitating graft revision. Six (3.9%) and 2 (4.4%) of these patients, respectively, had off-pump coronary artery bypass grafting and on-pump coronary artery bypass grafting.

CONCLUSION

Intraoperative fluorescence imaging demonstrated a low (1.5%) but well-defined incidence of intraoperative graft failure, which affects around 4% of patients. This emphasizes the need for routine assessment of graft patency. Intraoperative fluorescence imaging permits detection and revision of failed grafts in the operating room. We found no difference in the incidence of failed grafts when comparing on-pump and off-pump total arterial grafting.

Off-pump versus on-pump coronary artery bypass surgery: does the pump influence outcome?1 1No competing interests declared

BACKGROUND

This study assessed hospitalization outcome differences for patients undergoing off-pump coronary artery bypass (OPCAB) grafting compared with patients having coronary artery bypass grafting with cardiopulmonary bypass.

STUDY DESIGN

We conducted a nested case-control study from an 8-year, hospitalization cohort (n = 7,905) in which the data were collected prospectively. Inclusion criteria included a coronary artery bypass graft only and age greater than 18 years. Cases were patients undergoing OPCAB (n = 360) and controls were patients undergoing coronary artery bypass grafting with cardiopulmonary bypass (n = 1,080). Cases were matched to controls 1:3 on five variables: age (+/- 3 years), gender, diabetes, New York Heart Association Functional Classification, and surgical year (+/- 3 years). The 13 outcomes of interest were mortality, length of hospitalization, ICU length of stay, return to ICU, ventilator time, intraoperative complications, pulmonary complications, neurologic complications, renal complications, gastrointestinal complications, sternal wound infections, highest postoperative creatine kinase level, and units of blood products given during the procedure. Using logistic regression we controlled for eight confounding variables.

RESULTS

Patients undergoing OPCAB had a significantly shorter length of hospitalization (relative risk [RR] = 0.95; 95% CI, 0.91-0.99%), fewer pulmonary complications (RR = 0.45; 95% CI, 0.22-0.88%), fewer intraoperative complications (RR = 0.04; 95% CI, 0.0048-0.31%) fewer blood product units given (RR = 0.31; 95% CI, 0.14-0.42%) and lower postoperative creatine kinase (RR = 0.99; 95% CI, 0.98-0.99%). There were no considerable differences for the remaining nine outcomes, including mortality and neurologic complications.

CONCLUSIONS

Patients undergoing OPCAB had a considerably shorter length of hospitalization, had fewer pulmonary and intraoperative complications, and received a lower volume of blood products.

Off-pump myocardial revascularization is associated with less incidence of stroke in elderly patients

Several recent studies have highlighted the potential benefits of using off-pump coronary artery bypass (OPCAB) surgery, particularly in high-risk patients. The aim of this meta-analysis is to assess the effect of OPCAB on the incidence of stroke compared with coronary artery bypass grafting using cardiopulmonary bypass (CPB) in elderly patients. We performed a meta-analysis of all observational studies, published in MEDLINE between 1999 and 2002 and a comparison between the OPCAB and CPB techniques in elderly patients was performed with the outcome of interest being the incidence of stroke. Elderly patients were defined as those aged 70 years or older. Nine studies are included in the meta-analysis. The total number of subjects included was 4,475 patients, of which, 1,253 underwent OPCAB (28%) and 3,222 (72%) underwent CPB. The meta-analysis showed that the OPCAB technique was associated with significantly lower incidence of stroke in elderly patients compared with the CPB technique (1% vs 3%), with an odds ratio of 0.38% to 95% (CI, 0.22 to 0.65). We did not identify any significant heterogeneity and funnel plot asymmetry between the studies included in the meta-analysis. Meta-regression analysis including variables predicting stroke, mortality, and study characteristics did not show any associations affecting the calculated odds ratio of stroke. Despite the fact that this is a meta-analysis of observational studies and adjustment for differences in baseline risk factors between OPCAB and CPB patients was not possible, we believe that this study suggests that the OPCAB technique might be associated with reduced incidence of stroke in the elderly patients undergoing coronary artery bypass grafting.

Off-pump coronary artery bypass surgery: physiology and anaesthetic management †

Increasing interest is being shown in beating heart (off-pump) coronary artery surgery (OPCAB) because, compared with operations performed with cardiopulmonary bypass, OPCAB surgery may be associated with decreased postoperative morbidity and reduced total costs. Its appears to produce better results than conventional surgery in high-risk patient populations, elderly patients, and those with compromised cardiac function or coagulation disorders. Recent improvements in the technique have resulted in the possibility of multiple-vessel grafting in all coronary territories, with a graft patency comparable with conventional surgery. During beating-heart surgery, anaesthetists face two problems: first, the maintenance of haemodynamic stability during heart enucleation necessary for accessing each coronary artery; and second, the management of intraoperative myocardial ischaemia when coronary flow must be interrupted during grafting. The anaesthetic technique is less important than adequate management of these two major constraints. However, experimental and recent clinical data suggest that volatile anaesthetics have a marked cardioprotective effect against ischaemia, and might be specifically indicated. OPCAB surgery requires team work between anaesthetists and surgeons, who must be aware of each other's constraints. Some surgical aspects of the operation are reviewed along with physiological and anaesthetic data.

Reduced strokes in the elderly: the benefits of untouched aorta off-pump coronary surgery

BACKGROUND

Avoiding aortic manipulation during off-pump coronary artery bypass (OPCAB) reduces the risk for atheroembolic complications and may, thus, benefit elderly patients who are prone to atherosclerotic aortic involvement.

METHODS

During a period of 18 months (2000-2002), 160 consecutive OPCAB patients older than 75 years were evaluated. One hundred and three patients undergoing clampless OPCAB were compared to 57 patients in whom side clamps were applied. Clampless revascularization was achieved by in situ or T-graft arterial configurations.

RESULTS

Mean age was older (79.3 years vs 78.2, p = 0.049) and the prevalence (43% vs 7%, p < 0.0001) and severity of aortic disease was higher in the clampless group. The main conduits used were bilateral skeletonized internal thoracic artery (47%) and radial arteries (42%). More grafts were performed in the side-clamp group (2.5 +/- 0.5 vs 2.3 +/- 0.6, p = 0.023), however, revascularization of the postero-lateral territory was comparable. While early mortality (2.9% vs 7%, p = >or=0.05), perioperative myocardial infarction (3% vs 5%, p = >or=0.05), and sternal infections (none) were similar, the incidence of major neurological complications (0% vs 5.3%, p = 0.044) and the combined outcome of stroke or mortality (3% vs 12%, p = 0.035) were lower in the clampless group. Multivariate analysis identified side clamping as a predictor for the occurrence of stroke or mortality (OR, 6.28, CL 1.39-28.4, p = 0.017), increasing this risk by sixfold.

CONCLUSIONS

Clampless OPCAB is associated with reproducible neurological benefit. Improved neurological outcome may be conferred irrespective of the method of aortic screening in patients 75 years or older. The use of arterial conduits for this purpose is feasible despite the patients' advanced years.

L-arginine protects the mesenteric vascular circulation against cardiopulmonary bypass-induced vascular dysfunction

BACKGROUND

The aim of our study was to determine whether addition of the nitric oxide donor l-arginine at reperfusion may prevent the cardiopulmonary bypass (CPB)-induced vascular alterations in the intestine.

METHODS

Twelve dogs underwent 90-minute hypothermic CPB. After 60 minutes, the cardiac arrest-treated group (n = 6) received 40 mg/kg intravenous bolus l-arginine, followed by 3 mg/kg/min infusion for 20 minutes. Hemodynamic parameters, blood gases, lactate, and glucose were monitored. Reactive hyperemia (RH) in response to superior mesenteric artery ischemia and vasorelaxation to systemically administered vasoactive drugs (acetylcholine [ACH] and sodium nitroprusside) were assessed before and after CPB and defined as percent change of vascular resistance.

RESULTS

In the control group, CPB reduced reactive hyperemia (RH) (-26 +/- 15% vs -53 +/- 5%), and the response to ACH (-30 +/- 3% vs -42 +/- 7%). In the treated group, the post-CPB endothelial dysfunction was reversed (-37 +/- 1%, P <.05 vs control group) and RH partially recovered (-34 +/- 4%, P <.05). Administration of l-arginine resulted in a higher mesenteric oxygen delivery, increased nitrite/nitrate production, and lower lactate release from the mesenteric vascular circulation after reperfusion.

CONCLUSIONS

CPB disrupts some of the regulatory functions of the endothelial cell in the mesenterium and these are mostly related to nitric oxide unavailability. Systemic supplementation of l-arginine at reperfusion prevents the CPB-induced mesenteric endothelial dysfunction in association with an increased blood distribution and a reduced metabolic impairment.

Use of off-pump and on-pump CABG strategies in current clinical practice: the Clinical Outcomes Assessment Program of the state of Washington

BACKGROUND

The purpose of this study is to assess clinical outcomes and regional differences in the use of on-pump and off-pump CABG in current clinical practice.

METHODS

Between January 1, 1999, and December 31, 2000, there were 10,429 CABG procedures performed in 16 Washington state hospitals, all of which participate in Clinical Outcomes Assessment Program database. This analysis excluded patients with a history of prior CABG as well as those who underwent emergent surgery. After applying these exclusion criteria, 8402 patients (7169 on-pump and 1233 off-pump CABG procedures) were evaluated and presented as both unadjusted and risk-adjusted outcomes.

OUTCOMES

Off-pump CABG constituted 14.7% of all surgical revascularization procedures. These varied enormously among individual centers from an incidence of 0% to 68.9%. The use of off-pump CABG was not associated with a decreased risk of risk-adjusted hospital mortality or stroke, but was associated with a reduction in hospital stay > 7 days (OR 0.62, CI 0.51-0.76), ventilator > 24 hours (OR 0.52, CI 0.34-0.81), dialysis (OR 0.34, CI 0.14-0.86), and RBC transfusion (OR 0.5, CI 0.40-0.61).

CONCLUSIONS

Despite its highly variable use, off-pump CABG seems to be judiciously used in current clinical practice in the State of Washington and is associated with a decrease in morbidity in appropriately selected patients.

Current results of off-pump coronary artery bypass surgery

Whether to use or not use cardiopulmonary bypass-cardioplegic arrest to perform coronary artery bypass surgery is the main controversy presently facing our surgical specialty. The reported clinical outcomes are mainly retrospective and highly debatable for conclusiveness regarding the benefits of off-pump surgery. As more centers and larger patient cohorts are analyzed and reported, particularly over the last 2 years, off-pump surgery appears to provide significantly improved outcomes with decreased bleeding and transfusion requirements, less myocardial enzyme release, less ventilatory time, and decreased hospital stay and costs. Reported off-pump benefits for the major outcomes of operative mortality and stroke are encouraging, but less conclusive. From experienced centers, early off-pump angiographic graft patency has been comparable to previously published conventional results. High-risk, elderly patients may benefit the greatest from off-pump surgery. Although in relative technical infancy, off-pump coronary artery bypass grafting has demonstrated enough benefit outcomes that it is no longer an experimental procedure, but a valid surgical revascularization method requiring further investigation and continued usage.