Isolated bypass grafting of the left internal thoracic artery to the left anterior descending coronary artery: late consequences of incomplete revascularization

Sequential composite BIMA grafting for 3v-CAD: factors that predict successful outcome of the one-inflow and two-inflow revascularization techniques

OBJECTIVE

The effect of one-inflow and two-inflow coronary surgical revascularization techniques inclosing skeletonized double mammary artery (BIMA) as T-graft on outcome is studied.

METHODS

Early ad mid-term outcome of complete BIMA revascularization (C-T-BIMA) versus left-sided BIMA with right-sided aorto-coronary bypass (L-T-BIMA + R-CABG) is quantified and analyzed by multivariate logistic regression, Cox-regression, and Kaplan-Meier analysis in a series of 204 consecutive patients treated for triple-vessel coronary disease (3v-CAD).

RESULTS

The L-T-BIMA + R-CABG technique (n = 104) enables higher number of total (4.02 ± 0.87 vs. 3.71 ± 0.69, p = 0.015) and right-sided (1.21 ± 0.43 vs. 1.02 ± 0.32, p = 0.001) coronary anastomoses, improves total bypass flow (125.88 ± 92.41 vs. 82.50 ± 49.26 ml, p < 0.0001) and bypass flow/anastomosis (31.83 ± 23.9 vs.22.77 ± 14.23, p = 0.001), and enhances completeness of revascularization (84% vs.69%, p = 0.014) compared to C-T-BIMA strategy (n = 100), respectively. Although the incidence of MACCE was comparable in the two groups (8% vs.1.2%, p = 0.055), the progression of functional mitral regurgitation (FMR) was significantly lower after L-T-BIMA + R-CABG, then after C-T-BIMA (47% vs.64%, p = 0.017). The use of C-T-BIMA-technique (HR = 4.2, p = 0.01) and preoperative RCA occlusion (HR = 3.006, p = 0.023) predicted FMR progression, whereas L-T-Graft + R-CABG technique protected against it (X2 = 14.04, p < 0.0001) independent of the anatomic and clinical complexity (Syntax score I: HR = 16.2, p = 0.156, Syntax score II: HR = 1.901, p = 0.751), of early- (0.96% vs.2%, p = 0.617) and mid-term mortality (5.8% vs.4%, p = 0.748) when compared to C-T-BIMA, respectively.

CONCLUSIONS

The two-inflow coronary revascularization by L-T-BIMA + R-CABG better protects against FMR progression without increasing MACCE and mortality. Older patients with RCA occlusion and reduced LV-EF benefit most from the two-inflow L-T-BIMA + R-CABG technique. Younger 3v-CAD patients with normal LV-EF can preferentially be managed with the one-inflow C-T-BIMA; however, long-term outcome remains to be revealed.

Additional bypass graft or concomitant surgical ablation? Insights from the HEIST registry

BACKGROUND

Surgical ablation for atrial fibrillation at the time of isolated coronary artery bypass grafting is reluctantly attempted. Meanwhile, complete revascularization is not always possible in these patients. We attempted to counterbalance the long-term benefits of surgical ablation against the risks of incomplete revascularization.

METHODS

Atrial fibrillation patients undergoing isolated coronary artery bypass grafting for multivessel disease between 2012 to 2022 and included in the HEart surgery In atrial fibrillation and Supraventricular Tachycardia registry were divided into complete revascularization, complete revascularization with additional grafts, and incomplete revascularization cohorts; these were further split into surgical ablation and non-surgical ablation subgroups.

RESULTS

A total of 8,405 patients (78% men; age 69.3 ± 7.9) were included; of those, 5,918 (70.4%) had complete revascularization, and 556 (6.6%) had surgical ablation performed. Number of anastomoses was 2.7 ± 1.2. The median follow-up was 5.1 [interquartile range 2.1-8.8] years. In patients in whom complete revascularization was achieved, surgical ablation was associated with long-term survival benefit: hazard ratio 0.69; 95% confidence intervals (0.50-0.94); P = .020 compared with grafting additional lesions. Similarly, in patients in whom complete revascularization was not achieved, surgical ablation was associated with a long-term survival benefit of 0.68 (0.49-0.94); P = .019. When comparing surgical ablation on top of incomplete revascularization against complete revascularization without additional grafts or surgical ablation, there was no difference between the 2: 0.84 (0.61-1.17); P = .307, which was also consistent in the propensity score-matched analysis: 0.75 (0.39-1.43); P = .379.

CONCLUSION

To achieve complete revascularization is of utmost importance. However, when facing incomplete revascularization at the time of coronary artery bypass grafting in a patient with underlying atrial fibrillation, concomitant surgical ablation on top of incomplete revascularization is associated with similar long-term survival as complete revascularization without surgical ablation.

Revascularization of Occluded Right Coronary Artery and Outcome After Coronary Artery Bypass Grafting

OBJECTIVES

The aim of the present study was to evaluate the results of isolated coronary artery bypass grafting (CABG) with or without revascularization of the occluded right coronary artery (RCA).

METHODS

Patients undergoing isolated CABG were included in a prospective European multicenter registry. Outcomes were adjusted for imbalance in preoperative variables with propensity score matching analysis. Late outcomes were evaluated with Kaplan-Meier's method and competing risk analysis.

RESULTS

Out of 2,948 included in this registry, 724 patients had a total occlusion of the RCA and were the subjects of this analysis. Occluded RCA was not revascularized in 251 (34.7%) patients with significant variability between centers. Among 245 propensity score-matched pairs, patients with and without revascularization of occluded RCA had similar early outcomes. The nonrevascularized RCA group had increased rates of 5-year all-cause mortality (17.7 vs. 11.7%, p = 0.039) compared with patients who had their RCA revascularized. The rates of myocardial infarction and repeat revascularization were only numerically increased but contributed to a significantly higher rate of MACCE (24.7 vs. 15.7%, p = 0.020) at 5 year among patients with nonrevascularized RCA.

CONCLUSION

In this multicenter study, one-third of totally occluded RCAs was not revascularized during isolated CABG for multivessel coronary artery disease. Failure to revascularize an occluded RCA in these patients increased the risk of all-cause mortality and MACCEs at 5 years.

Impact of Functional vs Anatomic Complete Revascularization in Coronary Artery Bypass Grafting

BACKGROUND

This study was conducted to evaluate the impact of functional and anatomic complete revascularization on long-term clinical outcomes after coronary artery bypass grafting (CABG).

METHODS

Of 2034 patients who underwent primary isolated CABG between 2006 and 2017, 1162 patients who underwent off-pump CABG for 3-vessel disease and for whom data on functional and anatomic completeness of revascularization were available on the basis of preoperative myocardial single photon emission computed tomography and early postoperative graft angiography were enrolled. The median follow-up duration was 82.4 months (interquartile range, 50.8-122.4 months). Univariate and multivariate analyses were performed to evaluate the impact of the functional and anatomic completeness of revascularization on long-term survival.

RESULTS

Of 1162 patients, anatomic complete revascularization was achieved in 1014 patients (87.3%), whereas functional complete revascularization was achieved in 1077 patients (92.7%). Early mortality occurred in 7 patients. Late death occurred in 322 of 1155 early survivors. The 5- and 10-year overall survival rates were 84.3% and 66.7%, respectively. Univariate analyses demonstrated that functional completeness of revascularization was a statistically significant risk factor (P = .038), whereas anatomic completeness was not (P = .859). The multivariate analysis showed that functional completeness of revascularization (hazard ratio, 1.54; 95% CI, 1.08-2.22; P = .019) and age, underweight status, diabetes mellitus, chronic kidney disease, chronic obstructive pulmonary disease, and left ventricular dysfunction were significant factors associated with long-term survival.

CONCLUSIONS

Functional rather than anatomic completeness of revascularization has a significant impact on the long-term survival in patients who undergo CABG.

Off-pump coronary artery bypass grafting is safe and effective in patients with severe left ventricular dysfunction

OBJECTIVES

Severe left ventricular dysfunction (LVD) is associated with increased risk following coronary artery bypass grafting (CABG). Due to a dearth of reports on the choice of CABG technique in patients with LVD, this study aims to compare the outcomes of off-pump CABG (OPCAB) and conventional CABG (ONCAB) in such patients.

METHODS

Retrospective single-centre propensity-matched analysis comparing early- and long-term outcomes of OPCAB and ONCAB in patients with severe LVD. Primary outcome was long-term all-cause mortality.

RESULTS

Between 2002 and 2014, a total of 1161 consecutive patients with severe LVD underwent isolated CABG [442 patients underwent OPCAB and 719 ONCAB (430 matched pairs)]. Incomplete revascularization was observed more frequently among OPCAB than ONCAB patients (35.3% vs 21.6%; P < 0.01). The overall 30-day mortality was 5% and was comparable between the matched groups [OR 0.64 (0.34-1.22); P = 0.18]. OPCAB patients had shorter median hospital stay (11 vs 12 days; P = 0.02) and lower packed red blood cell transfusion rates [2.7 (2.21-3.19) vs 4.4 (3.56-5.24); P < 0.01]. Estimated adjusted survival was 86.0% vs 85.8%, 69.1% vs 65.5% and 59.9% vs 49.1% at 1, 5 and 10 years for OPCAB and ONCAB patients, respectively (P = 0.99). Long-term risk of mortality was similar between groups [hazard ratio (HR) 0.94 (0.66-1.32); P = 0.7]. Incomplete revascularization was weakly associated with increased risk of long-term all-cause mortality [HR 1.33 (0.99-1.77); P = 0.05].

CONCLUSIONS

OPCAB is safe and effective in patients with severe LVD. Although incomplete revascularization is more commonly observed in patients undergoing OPCAB, it is not associated with increased late mortality.

Non-Autologous Grafts in Coronary Artery Bypass Surgery: A Systematic Review

BACKGROUND

Suitable autologous conduits may be lacking when performing coronary artery bypass grafting (CABG). The aim of this review is to determine the status of non-autologous grafts in CABG.

METHODS

We conducted a literature search on MEDLINE All, Embase Classic and Embase through Ovid from 1960 to April 2020.

RESULTS

Of the 1579 records identified, 21 studies were included in the review. The following grafts were assessed for patency: 109 homologous saphenous veins (patency rates ranged from 66.7% at a median follow-up of 8.5 months to 0% at 6-12 and 7-18 months, respectively), 29 expanded polytetrafluoroethylene (ePTFE) grafts (from 80% at a median follow-up of 5 months to 14.3% at 45 months), 12 human umbilical veins (50% at a median follow-up of 6 months), 50 Bioflow bovine internal mammary arteries (from 15.8% to 0% at a mean follow-up of 9.5 and 19 months, respectively), 39 Perma-Flow grafts (80% and 76.9% at 1-3 and 12 months, respectively), 20 No-React bovine internal mammary arteries (57.1% at a median follow-up of 28 months and 23.1% at a mean follow-up of 7 months), 40 autologous venous endothelial cell-seeded ePTFE grafts (94.7% and 81% at a mean follow-up of 27 and 60 months, respectively) and 12 autologous venous endothelial cell-seeded cryopreserved homologous veins (83.3% at a mean follow-up of 8.5 months).

CONCLUSIONS

The goal of an alternative conduit with patency and attributes that match those of autografts remains elusive. Autologous endothelial cell-seeded synthetic grafts have demonstrated promising results but require further investigation.

Clinical outcomes of complete versus incomplete revascularization in patients treated with coronary artery bypass grafting: insights from the TiCAB trial

OBJECTIVES

In this post hoc analysis of the Ticagrelor in coronary artery bypass grafting (CABG) trial, we aimed to analyse patients treated with CABG receiving either complete revascularization (CR) or incomplete revascularization (ICR) independent from random allocation to either ticagrelor or aspirin.

METHODS

Of 1859 patients enrolled in the Ticagrelor in CABG trial, 1550 patients (83.4%) received CR and 309 patients (16.6%) ICR. Outcomes were evaluated regarding all-cause mortality, cardiovascular death, myocardial infarction (MI), repeat revascularization, stroke and bleeding within 12 months after CABG.

RESULTS

Baseline parameters revealed significant differences regarding clinical presentation (stable angina pectoris: CR 68.9% vs ICR 71.2%, instable angina pectoris: 14.1% vs 7.8%, non-ST elevation MI: 17.0% vs 21.0%, P ˂ 0.01), lesion characteristics (chronic total occlusion: CR 91.3% vs ICR 96.8%, P ˂ 0.01), operative technique [off-pump coronary artery bypass surgery (OPCAB): CR 3.0% vs ICR 6.1%, P ˂ 0.01] and number of utilized grafts (total number of grafts: 2.69/patient vs 2.49/patient, P ˂ 0.001). ICR patients displayed a significantly increased risk of repeat revascularization [hazard ratio (HR) 1.91, 95% confidence interval (CI) 1.16-3.16; P < 0.01] and percutaneous coronary intervention (HR 1.95, 95% CI 1.13-3.35; P < 0.05) within 12 months after CABG. Higher risk for repeat revascularization in ICR patients was independent from random allocation to either ticagrelor or aspirin and persisted after adjustment for baseline imbalances.

CONCLUSIONS

Patients with ICR presented more stable at the time of admission, but received less grafts, highly likely due to a higher rate of chronic total occlusion lesions and performed OPCAB. Although mortality presented no difference between groups, our results suggest that patients benefit from CR with regard to prevention of repeat revascularization.

Quantitative estimation of LIMA blood flow between extraluminal papavarine vs extraluminal papavarine plus intraluminal vasodilator cocktail in CABG patients

Objective:

In this study, we aimed at a comparative quantitative estimation of the difference in LIMA blood flow between LIMAs treated with topical papaverine alone and LIMAs treated with a combination of topical papaverine plus an intraluminal cocktail of papaverine, nitroglycerine, and milrinone.

Methods:

Nearly 50 consecutive patients with similar demographics undergoing elective on-pump CABG were recruited for the study. After pedicled LIMA harvest, topical papaverine was sprayed on the pedicle and kept enveloped in papaverine soaked gauze. LIMA flow was then estimated. Later, intraluminal vasodilator solution of papaverine, NTG, milrinone, and heparinized blood were instilled in LIMA, and LIMA flows were estimated.

Results:

The mean LIMA flows with topical papaverine alone was 47.19 mL/min whereas the mean LIMA flows with topical papaverine plus intraluminal cocktail was 104 mL/min. There was a significant difference between the two flows as their mean was 56.815 mL/min and the paired t-test for significance had a P value of 0.0001.

Conclusion:

There was a significant difference in the LIMA flow when the LIMA had been treated with the intraluminal instillation of the vasodilator cocktail in addition to the topical application of papaverine solution. Therefore, intraluminal vasodilator cocktail of milrinone, NTG, and papaverine mixed with heparinized blood in addition to topical papaverine is a simple and effective method for LIMA preparation in CABG.

Complete versus incomplete coronary revascularization: definitions, assessment and outcomes

Coronary artery disease is the leading cause of morbidity and mortality worldwide. Selected patients with obstructive coronary artery disease benefit from revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery. Many (but not all) studies have demonstrated increased survival and greater freedom from adverse cardiovascular events after complete revascularization (CR) than after incomplete revascularization (ICR) in patients with multivessel disease. However, achieving CR after PCI or CABG surgery might not be feasible owing to patient comorbidities, anatomical factors, and technical or procedural considerations. These factors also mean that comparisons between CR and ICR are subject to multiple confounders and are difficult to understand or apply to real-world clinical practice. In this Review, we summarize and critically appraise the evidence linking various types of ICR to adverse outcomes in patients with multivessel disease and stable ischaemic heart disease, non-ST-segment elevation acute coronary syndrome or ST-segment elevation myocardial infarction, with or without cardiogenic shock. In addition, we provide practical recommendations for revascularization in patients with high-risk multivessel disease to optimize their long-term clinical outcomes and identify areas requiring future clinical investigation.

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.

Effect of Papaverine on Left Internal Mammary Artery Flow: Topical Spraying versus Perivascular Injection Method

Objective

To analyze two techniques of papaverine application, topical spray on the harvested left internal mammary artery (LIMA) and perivascular injection, to find out their ability to improve LIMA flow.

Methods

Forty patients were randomized into two groups. In Group 1, papaverine was sprayed on the harvested pedunculated LIMA. In Group 2, papaverine was delivered into the perivascular plane. Drug dosage was the same for both groups. LIMA flow was measured 20 minutes after applying papaverine. Blood flow was recorded for 20 seconds and flow per minute was calculated. The systemic mean pressures were maintained at 70 mmHg during blood collection. The data collected was statistically evaluated and interpreted.

Results

The LIMA blood flow before papaverine application in the Group 1 was 51.9±13.40 ml/min and in Group 2 it was 55.1±15.70 ml/min. Statistically, LIMA flows were identical in both groups before papaverine application. The LIMA blood flow, post papaverine application, in Group 1 was 87.20±13.46 ml/min and in Group 2 it was 104.7±20.19 ml/min. The Group 2 flows were statistically higher than Group 1 flows.

Conclusion

Papaverine delivery to LIMA by the perivascular injection method provided statistically significant higher flows when compared to the topical spray method. Hence, the perivascular delivery of papaverine is more efficient than the spray method in improving LIMA blood flow.

The effect of completeness of revascularization during CABG with single versus multiple arterial grafts

INTRODUCTION

Incomplete coronary revascularization is associated with suboptimal outcomes. We investigated the long-term effects of Incomplete, Complete, and Supra-complete revascularization and whether these effects differed in the setting of single-arterial and multi-arterial coronary artery bypass graft (CABG).

METHODS

We analyzed 15-year mortality in 7157 CABG patients (64.1 ± 10.5 years; 30% women). All patients received a left internal thoracic artery to left anterior descending coronary artery graft with additional venous grafts only (single-arterial) or with at least one additional arterial graft (multi-arterial) and were grouped based on a completeness of revascularization index (CRI = number of grafts minus the number of diseased principal coronary arteries): Incomplete (CRI ≤ -1 [N = 320;4.5%]); Complete (CRI = 0 [N = 2882;40.3%]; reference group); and two Supra-complete categories (CRI = +1[N = 3050; 42.6%]; CRI ≥ + 2 [N = 905; 12.6%]). Risk-adjusted mortality hazard ratios (AHR) were calculated using comprehensive propensity score adjustment by Cox regression.

RESULTS

Incomplete revascularization was rare (4.5%) but associated with increased mortality in all patients (AHR [95% confidence interval] = 1.53 [1.29-1.80]), those undergoing single-arterial CABG (AHR = 1.27 [1.04-1.54]) and multi-arterial CABG (AHR = 2.18 [1.60-2.99]), as well as in patients with 3-Vessel (AHR = 1.37 [1.16-1.62]) and, to a lesser degree, with 2-Vessel (AHR = 1.67 [0.53-5.23]) coronary disease. Supra-complete revascularization was generally associated with incrementally decreased mortality in all patients (AHR [CRI = +1] = 0.94 [0.87-1.03]); AHR [CRI ≥ +2] = 0.74 [0.64-0.85]), and was driven by a significantly decreased mortality risk in single-arterial CABG (AHR [CRI = +1] = 0.90 [0.81-0.99]; AHR [CRI ≥ +2] = 0.64 [0.53-0.78]); and 3-Vessel disease patients (AHR [CRI = +1] = 0.94 [0.86-1.04]; and AHR [CRI ≥ +2] = 0.75 [0.63-0.88]) with no impact in multi-arterial CABG (AHR [CRI = +1] = 1.07 [0.91-1.26]; AHR [CRI ≥ +2] = 0.93 [0.73-1.17]).

CONCLUSIONS

Incomplete revascularization is associated with decreased late survival, irrespective of grafting strategy. Alternatively, supra-complete revascularization is associated with improved survival in patients with 3-Vessel CAD, and in single-arterial but not multi-arterial CABG.

Incomplete revascularization: what the surgeon needs to know

For many years, the concept of "complete revascularization" (CR) was considered an absolute truth in coronary surgery with improved long-term survival and a lower rate of reintervention. This was derived from early publications which showed a survival benefit for patients undergoing coronary artery bypass grafting (CABG) who received CR. Many advances in the field of coronary revascularization have been made in the years that passed since those publications, including more frequent use of percutaneous coronary intervention (PCI) in patients with multivessel disease (MVD). This has led some to question the importance of CR and raise the option of "reasonable incomplete revascularization" (IR) for selected patients. The definition of CR is variable in the literature with the two most common definitions being an anatomical (revascularization of all coronary segments with stenosis and larger than a predefined size) and a functional definition (where revascularization is considered complete if all ischemic and viable territories are reperfused). No randomized control trials have been conducted to compare complete versus IR, and a significant proportion of data is based on post hoc analysis of data from randomized control trials and registries. Multiple studies have proven that CR is achieved more frequently with CABG then with PCI. A review of the available data from the past three to four decades shows a trend toward improved results with CR, regardless of the reperfusion strategy chosen. This should impact the heart team discussion when choosing a revascularization strategy and impact the surgical decision making while preforming CABG. IR can be part of a hybrid revascularization strategy or be reserved for rare cases where the cost of achieving CR much outweighs the benefit.

Residual SYNTAX score following coronary artery bypass grafting

Objectives

To quantify residual coronary artery disease measured using the SYNTAX score (SS) and its relation to outcomes after coronary artery bypass grafting (CABG).

Methods

We conducted a retrospective analysis on a consecutive series of 1608 patients [mean age 68 years, standard deviation (SD): 7, F:M, 242:1366] undergoing first-time isolated CABG from 2004 to 2015. The baseline SS was retrospectively determined from preoperative angiograms, and the residual SS (rSS) was measured during assessment of the actual operative report for each patient after CABG. Patients were then stratified according to tercile cut points of low (rSS low 0-11, N  = 537), intermediate (rSS mid  >11-18.5, N  = 539) and high residual SS (rSS high  >18.5, N  = 532). The Cox regression model was used to investigate the impact of rSS on major adverse cardiac and cerebrovascular events (MACCE) at 1 year.

Results

The mean preoperative SS was 26.6 (SD: 9.4) (range 10.1-53), and the residual SS after CABG was 15.3 (SD: 8.4) (range 0-34) ( P  <   0.001 versus preoperative). At 1 year, cumulative incidence of MACCE in the low rSS was 1.5% ( N  = 8/537), 4.5% ( N  = 24/539) in the intermediate and 8.8% ( N  = 47/532) in the high rSS group. Kaplan-Meier analysis showed a statistically significant difference of MACCE-free survival between the three groups (log-rank test, P  <   0.001). The estimated MACCE-free survival rate at 1 year was 98.1% [standard error (SE): 1.6] for the rSS low , 95.5% (SE: 1.9) for the rSS mid , and 90.5% (SE: 1.3) for the rSS high group, respectively. After multivariable adjustment, the rSS high group was independently associated with a higher incidence of MACCE at 1 year (hazard ratio 1.92, 95% confidence interval 1.21-3.23) compared to the rSS low group.

Conclusions

These unanticipated findings suggest that a residual SS may be a useful tool for risk stratification of patients undergoing isolated first-time CABG. Our study may set the stage for further investigations addressing this important clinical question.

The Surgical Treatment of Coronary Artery Occlusive Disease: Modern Treatment Strategies for an Age Old Problem

Coronary artery disease remains a formidable challenge to clinicians. Percutaneous interventions and surgical techniques for myocardial revascularization continue to improve. Concurrently, in light of emerging data, multiple practice guidelines have been published guiding clinicians in their therapeutic decisions. The multidisciplinary Heart Team concept needs to be embraced by all cardiovascular providers to optimize patient outcomes.

Revascularization in ischemic heart failure with reduced left ventricular ejection fraction. The impact of complete revascularization

Heart failure is a growing problem worldwide, with coronary artery disease being the underlying cause of over two-thirds of cases. Revascularization in this group of patients may potentially inhibit the progressive damage to the myocardium and lead to improved outcomes, but data in this area are scarce. This article emphasizes the role of qualification for revascularization and selection of method (percutaneous coronary intervention vs. coronary artery bypass grafting) and subsequently focuses on the issue of completeness of revascularization in this group of patients.

Does a similar procedure result in similar survival for women and men undergoing isolated coronary artery bypass grafting?

OBJECTIVES

To (1) identify sex-related differences in risk factors and revascularization strategies for patients undergoing coronary artery bypass grafting (CABG), (2) assess whether these differences influenced early and late survival, and (3) determine whether clinical effectiveness of the same revascularization strategy was influenced by sex.

METHODS

From January 1972 to January 2011, 57,943 adults-11,009 (19%) women-underwent primary isolated CABG. Separate models for long-term mortality were developed for men and women, followed by assessing sex-related differences in strength of risk factors (interaction terms).

RESULTS

Incomplete revascularization was more common in men than women (26% vs 22%, P < .0001), but women received fewer bilateral internal thoracic artery (ITA) grafts (4.8% vs 12%; P < .0001) and fewer arterial grafts (68% vs 70%; P < .0001). Overall, women had lower survival than men after CABG (65% and 31% at 10 and 20 years, respectively, vs 74% and 41%; P ≤ .0001), even after risk adjustment. Incomplete revascularization was associated equally (P > .9) with lower survival in both sexes. Single ITA grafting was associated with equally (P = .3) better survival in women and men. Although bilateral ITA grafting was associated with better survival than single ITA grafting, it was less effective in women-11% lower late mortality (hazard ratio, 0.89 [0.77-1.022]) versus 27% lower in men (hazard ratio, 0.73 [0.69-0.77]; P = .01).

CONCLUSIONS

Women on average have longer life expectancies than men but not after CABG. Every attempt should be made to use arterial grafting and complete revascularization, but for unexplained reasons, sex-related differences in effectiveness of bilateral arterial grafting were identified.

Completeness of revascularization and its impact on the outcomes of a staged approach of percutaneous coronary intervention followed by minimally invasive valve surgery for patients with concomitant coronary artery and valvular heart disease

BACKGROUND

A staged approach of percutaneous coronary intervention (PCI) followed by minimally invasive valve surgery (MIVS) is an alternative to the conventional combined coronary artery bypass and valve surgery for patients with concomitant coronary artery and valve disease. Limited data exist on degree of the completeness of revascularization achieved with this approach and its impact on outcomes.

METHODS

A total of 138 patients, who underwent a staged approach between January 2009 and June 2013, were retrospectively evaluated. Coronary angiograms were reviewed by two cardiologists blinded to outcomes and were then categorized into two groups: complete or incomplete revascularization, which was defined as ≥1 major epicardial coronary arteries of at least 2.0 mm diameter with ≥70% untreated obstruction after the index PCI and before MIVS.

RESULTS

Complete and incomplete revascularization was achieved in 105 (76%) and 33 (24%) patients, respectively. The patients with incomplete revascularization had a lower ejection fraction, a higher STS score, and more prior myocardial infarctions and multi-vessel coronary artery disease. There were no differences in the post-operative complications, 30-day mortality, or 3-year survival (84 vs. 83%, P = 0.68). After a median follow-up of 29 months, incompletely revascularized patients had a higher incidence of acute coronary syndrome (2.9 vs. 12.9%, P = 0.05).

CONCLUSIONS

In patients undergoing a staged approach of PCI followed by MIVS, incomplete revascularization did not significantly impact the short or mid-term survival, but was associated with an increased incidence of acute coronary syndrome at follow-up. © 2015 Wiley Periodicals, Inc.

Long-term outcomes of complete versus incomplete revascularization for patients with multivessel coronary artery disease and left ventricular systolic dysfunction in drug-eluting stent era

We aimed to investigate that complete revascularization (CR) would be associated with a decreased mortality in patients with multivessel disease (MVD) and reduced left ventricular ejection fraction (LVEF). We enrolled a total of 263 patients with MVD and LVEF <50% who had undergone percutaneous coronary intervention with drug-eluting stent between March 2003 and December 2010. We compared major adverse cardiac and cerebrovascular accident (MACCE) including all-cause death, myocardial infarction, any revascularization, and cerebrovascular accident between CR and incomplete revascularization (IR). CR was achieved in 150 patients. During median follow-up of 40 months, MACCE occurred in 52 (34.7%) patients in the CR group versus 51 (45.1%) patients in the IR group (P=0.06). After a Cox regression model with inverse-probability-of-treatment-weighting using propensity score, the incidence of MACCE of the CR group were lower than those of the IR group (34.7% vs. 45.1%; adjusted hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.44-0.95, P=0.03). The rate of all-cause death was significantly lower in patients with CR than in those with IR (adjusted HR, 0.48; 95% CI, 0.29-0.80, P<0.01). In conclusion, the achievement of CR with drug-eluting stent reduces long-term MACCE in patients with MVD and reduced LVEF.

On-pump beating-heart versus conventional coronary artery bypass grafting for revascularization in patients with severe left ventricular dysfunction: early outcomes

BACKGROUND

We sought to evaluate the effects of on-pump beating-heart versus conventional coronary artery bypass grafting techniques requiring cardioplegic arrest in patients with coronary artery disease with left ventricular dysfunction.

METHODS

We report the early outcomes associated with survival, morbidity and improvement of left ventricular function in patients with low ejection fraction who underwent coronary artery bypass grafting between August 2009 and June 2012. Patients were separated into 2 groups: group I underwent conventional coronary artery bypass grafting and group II underwent an on-pump beating-heart technique without cardioplegic arrest.

RESULTS

In all, 131 patients underwent coronary artery bypass grafting: 66 in group I and 65 in group II. Left ventricular ejection fraction was 26.6% ± 3.5% in group I and 27.7% ± 4.7% in group II. Left ventricular end diastolic diameter was 65.6 ± 3.6 mm in group I and 64.1 ± 3.2 mm in group II. There was a significant reduction in mortality in the conventional and on-pump beating-heart groups (p < 0.001). Perioperative myocardial infarction and low cardiac output syndrome were higher in group I than group II (both p < 0.05). Improvement of left ventricular function after the surgical procedure was better in group II than group I.

CONCLUSION

The on-pump beating-heart technique is the preferred method for myocardial revascularization in patients with left ventricular dysfunction. This technique may be an acceptable alternative to the conventional technique owing to lower postoperative mortality and morbidity.

Intramyocardial transfer of hepatocyte growth factor as an adjunct to CABG: phase I clinical study

The purpose of this phase I clinical trial was to evaluate the safety, tolerability and potential efficacy of VM202, naked DNA expressing two isoforms of hepatocyte growth factor, as an adjunct therapy to coronary artery bypass grafting (CABG) in patients with ischemic heart disease (IHD). Nine patients were assigned to receive increasing doses (0.5 to 2.0 mg) of VM202 injected into the right coronary artery (RCA) territory following completion of CABG for the left coronary artery territory. Patients were evaluated for safety and tolerability, and changes in myocardial functions were monitored via echocardiography, cardiac magnetic resonance imaging and myocardial single photon emission computed tomography throughout 6-month follow-up period. No serious complication related to VM202 was observed throughout the 6-month follow-up period. Global myocardial functions (wall motion score index, P=0.0084; stress perfusion, P=0.0002) improved during the follow-up period. In the RCA region, there was an increase in the stress perfusion (baseline vs 3-month, P=0.024; baseline vs 6-month, P=0.024) and also in the wall thickness of the diastolic and systolic phases. Intramyocardial injection of VM202 can be safely used in IHD patients with the tolerable dose of 2.0 mg. In addition, VM202 might appear to have improved regional myocardial perfusion and wall thickness in the injected region.

Complete revascularization is compromised in off-pump coronary artery bypass grafting

OBJECTIVE

Patients who undergo off-pump coronary artery bypass grafting (OPCAB) commonly receive fewer bypass grafts and are more often incompletely revascularized compared with those receiving conventional coronary artery bypass (CCAB) recipients. Because this can compromise survival, we sought to determine whether patients undergoing OPCAB are incompletely revascularized and whether this affects long-term survival and freedom from cardiac events.

METHODS

OPCAB cases (n = 411) performed from January 1, 1997 to June 30, 2003 were considered for inclusion and matching with 874 randomly selected, contemporary CCAB cases. After propensity matching, 308 OPCAB cases and 308 CCAB cases were included in the final analysis. We compared the number of bypass grafts and the completeness of revascularization by coronary territory. Survival and readmission for cardiac causes were monitored for up to 10 years postoperatively, with a median follow-up period of 5.9 years.

RESULTS

On average, the patients undergoing OPCAB received significantly fewer distal anastomoses than did those undergoing CCAB (mean ± standard deviation, 2.6 ± 0.9 vs 3.0 ± 1.0, P < .0001). The circumflex territory was the most likely territory to be ungrafted during OPCAB in patients with angiographically significant obstruction (P = .0006). The frequency of complete revascularization was significantly different between the 2 groups (OPCAB, 79.2% vs CCAB, 88.3%; P = .0.002). The OPCAB group had a significantly greater rate of total arterial grafting (OPCAB, 66.6% vs CCAB, 49.7%; P = .0001). No difference was seen in 8-year survival or freedom from cardiac cause hospital readmission between the 2 groups.

CONCLUSIONS

Despite receiving fewer distal anastomoses and the decreased frequency of complete revascularization, OPCAB and CCAB techniques produced comparable results.

Impact of incomplete surgical revascularization on survival

Complete revascularization is considered superior to incomplete revascularization (IR), with better long-term survival and a lower rate of reintervention. However, it has yet to be established whether this difference is due directly to IR as a surgical strategy or whether this approach is merely a marker of more severe coronary disease and more rapid progression. We believe that IR is a prognostic marker for a more complex coronary pathology, and adverse effects are probably due to the preoperative condition of the patient. In fact, although IR may negatively affect long-term outcomes, it may be, when wisely chosen, the ideal treatment strategy in selected high-risk patients. IR can derive from a surgical strategy of target vessel revascularization, where the impact of surgery is minimized to reduce perioperative mortality and morbidity, aiming to achieve the best feasible safe revascularization.

Early increase in myocardial perfusion after stem cell therapy in patients undergoing incomplete coronary artery bypass surgery

Incomplete revascularization is associated with worse long-term outcomes. Autologous bone marrow cells (BMC) have recently been tested in patients with severe coronary artery disease. We tested the hypothesis that intramyocardial injection of autologous BMC increases myocardial perfusion in patients undergoing incomplete coronary artery bypass grafting (CABG). Twenty-one patients (19 men), 59 ± 7 years old, with limiting angina and multivessel coronary artery disease (CAD), not amenable to complete CABG were enrolled. BMC were obtained prior to surgery, and the lymphomonocytic fraction separated by density gradient centrifugation. During surgery, 5 mL containing 2.1 ± 1.3 × 108 BMC (CD34+ = 0.8 ± 0.3%) were injected in the ischemic non-revascularized myocardium. Myocardial perfusion was assessed by magnetic resonance imaging (MRI) at baseline and 1 month after surgery. The increase in myocardial perfusion was compared between patients with <50% (group A, n = 11) with that of patients with >50% (group B, n = 10) of target vessels (stenosis ≥ 70%) successfully bypassed. Injected myocardial segments included the inferior (n = 12), anterior (n = 7), and lateral (n = 2) walls. The number of treated vessels (2.3 ± 0.8) was significantly smaller than the number of target vessels (4.2 ± 1.0; P < 0.0001). One month after surgery, cardiac MRI showed a similar reduction (%) in the ischemic score of patients in group A (72.5 ± 3.2), compared to patients in group B (78.1 ± 3.2; P = .80). Intramyocardial injection of autologous BMC may help increase myocardial perfusion in patients undergoing incomplete CABG, even in those with fewer target vessels successfully treated. This strategy may be an adjunctive therapy for patients suffering from a more advanced (diffuse) CAD not amenable for complete direct revascularization.

Off-pump coronary artery bypass vs percutaneous coronary intervention. Therapeutic strategies for 3-vessel coronary artery disease: OPCAB vs PCI(PCI-Side)

Coronary artery bypass graft (CABG) surgery is still the best therapy for patients with multivessel and left main coronary artery disease. Recently, the introduction of percutaneous coronary intervention (PCI) with drug-eluting stents (DES) in these patients has improved the restenosis rate compared with bare metal stents. Furthermore, according to the results of the SYNTAX trial, no differences were found in the frequencies of mortality or myocardial infarction between CABG and PCI patients. PCI with DES is being increasingly performed for the treatment of patients with either left main trunk, diffuse, or multivessel lesions. In Japan, to avoid any side effects from cardiopulmonary bypass, off-pump coronary artery bypass (OPCAB) was performed in 66% of the total isolated CABG procedures in 2009, and is markedly different from the procedures performed in North America and Europe. However, the comparative effectiveness of PCI and OPCAB remains uncertain. In the present study, the current evidence from randomized trials, a meta-analysis and several observation studies are reviewed.

Evaluation of revascularization subtypes in octogenarians undergoing coronary artery bypass grafting

BACKGROUND

Recent data suggest that octogenarians' long-term survival after complete coronary artery bypass graft revascularization is superior to incomplete revascularization. Discriminating between variable definitions of "complete" complicates interpretation of survival data. We aimed to clarify octogenarian long-term survival rates by stratifying revascularization subtypes.

METHODS AND RESULTS

From 1986 to 2007, 580 patients 80 to 94 years of age underwent coronary artery bypass graft. Functional complete revascularization was defined as at least 1 graft to all diseased coronary vessels with >50% stenosis. Traditional complete revascularization was defined as 1 graft to each major arterial system with at least 50% stenosis. Incomplete revascularization was defined as leaving diseased, ungrafted regions. Revascularization was functional in 279 (48%), traditional in 181 (31%), and incomplete in 120 (21%). Long-term survival was evaluated by Kaplan-Meier analysis. Of 537 operative survivors, there were 402 late deaths. Cumulative long-term survival totaled 2890 patient-years. Late survival (Kaplan-Meier) was similar between functional (mean, 6.8 years) and traditional (6.7 years) groups (P=0.51), but diminished with incomplete (4.2 years) revascularization (P=0.007). Survival by group at 5 years was: 59+/-3% functional, 57+/-4% traditional, and 45+/-5% incomplete. Survival at 8 years was: 40+/-3% functional, 37+/-4% traditional, and 26+/-5% incomplete. To minimize selection bias in patients with limited life expectancy, Kaplan-Meier analysis was repeated including only patients with survival >12 months. Survival was again impaired with incomplete revascularization (P=0.04), and there was no difference between functional and traditional complete revascularization (P=0.73).

CONCLUSIONS

Bypassing all diseased arterial vessels after revascularization does not afford significant long-term survival advantage compared to a traditional approach. Incomplete revascularization, related to more extensive disease, is associated with an 18% decline in survival. These data suggest that it is important to avoid incomplete revascularization in octogenarians, but the supplementary endeavor required to perform functional complete revascularization does not improve survival.

Incomplete revascularization reduces survival benefit of coronary artery bypass grafting: role of off-pump surgery

OBJECTIVE

We sought to analyze the influence, if any, of incomplete revascularization and on/off-pump techniques on long-term mortality after coronary artery bypass grafting.

METHODS

A total of 9408 patients undergoing coronary artery bypass grafting, 8461 on pump and 947 off pump, operated on between 1995 and 2004 were included in the study. Adjusted hazard function for long-term mortality was estimated with Poisson regression analysis in a model that included variables reflecting completeness of revascularization, operative method (on/off pump), and background risk factors for death.

RESULTS

Mean follow-up after surgical intervention for survivors was 5.0 +/- 2.8 years (range, 0.5-10.5 years), with a total follow-up of 45,076 patient years. Leaving 1 diseased vascular segment without a bypass graft in 2- or 3-vessel disease did not increase the hazard ratio for death in comparison with complete revascularization (hazard ratio, 1.05; 95% confidence interval, 0.87-1.27; P = .60). In contrast, leaving 2 vascular segments without a bypass graft in 3-vessel disease was associated with an increased hazard ratio for death (hazard ratio, 1.82; 95% confidence interval, 1.15-2.85; P = .01). Incomplete revascularization was more common in the off-pump group (P < .001) in our study. If adjusting for incomplete revascularization, there was no significant influence of the use of on/off-pump techniques on the hazard ratio for death (hazard ratio, 1.08; 95% confidence interval, 0.82-1.40; P = .57).

CONCLUSIONS

Incomplete revascularization of patients with 3-vessel disease is an independent risk factor for increased long-term mortality after coronary artery bypass grafting. In contrast, the use of on- or off-pump techniques had no significant effect on survival after adjusting for incomplete revascularization.

The late open infarct-related artery hypothesis: evidence-based medicine or not?

Randomized clinical trials have clearly shown that early reperfusion of coronary arteries is the established treatment of myocardial infarction preserving left ventricular function and reducing mortality. However, late patency of the infarct-related artery is an independent predictor of survival leading to the late open-artery hypothesis. This concept implies restoration of antegrade blood flow of the infarct-related artery in patients with myocardial infarction to improve survival by mechanisms less time-dependent or even time-independent. Possible explanations for this benefit include improved left ventricular function and electrical stability by perfusion of hibernating myocardium, accelerated infarct healing and limitation of ventricular remodeling. This review focuses on the evidence of late recanalization of occluded infarct-related arteries in patients with coronary artery disease.

Skin-derived microorgan autotransplantation as a novel approach for therapeutic angiogenesis

Despite promising preclinical results, transient single-factor-based therapeutic angiogenesis has shown no definitive benefits in clinical trials. The use of skin-derived microorgans (SMOs), capable of sustained expression of angiogenic factors and sustained viability with their cellular and extracellular elements, constitutes an attractive alternative. We sought to evaluate the efficacy of SMO implantation in a porcine model of chronic myocardial ischemia. Eighteen pigs underwent placement of an ameroid constrictor on the proximal circumflex artery. Three weeks later, split-thickness skin biopsies were harvested and pigs were randomized to lateral wall implantation of either 8 or 16 SMOs or blank injections. The procedure was safe and resulted in no adverse events. Three weeks after treatment, SMO implantation resulted in significant improvement of lateral wall perfusion during pacing, assessed by isotope-labeled microspheres [post- vs. pretreatment ratios of lateral/anterior wall blood flow were 1.31 ± 0.09 (SMOs) and 1.04 ± 0.06 (controls); P = 0.03]. No significant difference in angiographic scores was observed. Microvascular relaxation in response to VEGF was impaired in the ischemic territory of the control group but returned to normal after SMO implantation, indicating restoration of endothelial function. Molecular studies showed significant increases in VEGF and CD31 expression in the ischemic area of treated animals. Morphometric analysis showed increased neovascularization with SMO treatment. Autotransplantation of SMOs constitutes a novel approach for safe and effective therapeutic angiogenesis with improvement in perfusion, normalization of microvascular reactivity, and increased expression of VEGF and CD31.

Single versus sequential saphenous vein grafting of the circumflex system: a flowmetric study

OBJECTIVE

We sought to evaluate if patients with proximal critical circumflex (CX) lesions did better with single SV-CABG on the best obtuse marginal (OM), or with sequential SV-CABG on two OM branches.

DESIGN

Ninety patients were prospectively randomised to single SV-CABG on the best OM (sSV-CABG-45 patients; Group A) or to sequential SV-CABG on 2 OM (seqSV-CABG 45 patients; Group B). Transit-time flowmetry (TTF), and graft flow reserve were evaluated. Recurrent angina, acute myocardial infarction, readmission for coronary reintervention were defined "treatment failure" during follow-up.

RESULTS

SeqSV-CABG showed better intraoperative maximum (119.1+/-57.5 ml/min vs. sSV-CABG 62.4+/-29.6; p=0.001), mean (56.3+/-31.5 ml/min vs. 30.8+/-12.8; p=0.0001), minimum flow (22.8+/-9.2 ml/min vs. 11.8+/-8.9; p=0.001) and P.I. (0.71+/-0.4 vs.1.46+/-0.9; p=0.006). Graft flow reserve also proved to be higher (95.4+/-29.7 ml/min mean flow vs. sSV-CABG 42.3+/-15.2 ml/min mean flow; p=0.0001; flow reserve 1.72+/-0.99 vs 1.32+/-1.09; p=0.001) as well as freedom from treatment failure (97.5+/-0.5% vs 88.7+/-0.4%; p=0.05).

CONCLUSIONS

SeqSV-CABG showed higher TTF flows, with no incremental risk for perioperative morbidity. Higher flows and graft flow reserve may allow lower treatment failure at mid-term follow-up.

Off-pump bypass of the left anterior descending coronary artery: 23- to 34-year follow-up

OBJECTIVE

We sought to develop a baseline for long-term survival of patients after off-pump bypass of the left anterior descending coronary artery with the heart beating.

METHODS

We reviewed results for 241 consecutive patients with significant obstruction of the left anterior descending coronary artery who underwent surgery between November 1969 and the end of 1980. The off-pump operative technique involved elevating and stabilizing a segment of the distal left anterior descending coronary artery with 4 traction sutures. Starting in 1973, an internal thoracic artery became the graft of choice, so that a total of 171 patients received an internal thoracic artery bypass graft, and 70 patients received a saphenous vein graft.

RESULTS

The median survival of patients with internal thoracic artery grafts was 23.7 years versus 17.9 years for patients with venous grafts (P < .02). Early patency of arterial grafts was 95%, and late patency was 90%. There were 2 (0.8%) operative deaths. Seventy of the 74 patients still alive in 2003 were interviewed by telephone, and 40 (57%) did not require additional invasive treatment, which is consistent with our finding that more than 50% of our patients after bypass of the left anterior descending coronary remained stable without obstruction of the right or circumflex arteries. However, atherosclerosis progressed in 30 (43%) of the survivors, who underwent reinterventions.

CONCLUSIONS

Off-pump bypass of the left anterior descending coronary artery with an internal thoracic artery can be done on a beating heart safely and results in median survival of patients for more than 23 years.

Endothelial cell-seeded bovine internal mammary artery for complete revascularization

We present a 79-year-old woman with coronary heart disease who underwent complete revascularization by using a No-React bovine internal mammary artery seeded with autologous endothelial cells. Her postoperative course was uneventful, and the patient was recently in New York Heart Association functional class I. Multislice computed tomography imaging showed patent grafts at 20 months of follow-up.