Unmeasured Confounders in Observational Studies Comparing Bilateral Versus Single Internal Thoracic Artery for Coronary Artery Bypass Grafting: A Meta-Analysis

Surgeon Frequency of Aortic Root Enlargement and Long-Term Survival in Medicare Beneficiaries Undergoing Surgical Aortic Valve Replacement

Aortic root enlargement (ARE) is a variably performed during surgical aortic valve replacement (SAVR) to minimize patient-prothesis mismatch (PPM), but its impact on survival remains under-evaluated. We retrospectively analyzed Medicare beneficiaries (1999-2019) undergoing isolated SAVR with or without non-Konno ARE. Procedural details were doubly-adjudicated by ICD and CPT codes. Overlap propensity score weighting adjusted for confounders. Restricted mean survival times (RMST) at 30-days and 20-years were compared. Surgeons were stratified by ARE frequency, and survival was analyzed using risk-adjusted Kaplan-Meier estimates in both "as-treated" (SAVR vs SAVR+ARE) and "surgeon-preference" (never-ARE vs frequent-ARE surgeons) analyses. Of 214,266 beneficiaries undergoing isolated SAVR, 6,652 (3.1%) underwent SAVR+ARE. From 1999 to 2019, ARE utilization increased from 2.1% to 6.4% (Cochran-Armitage Z-statistic: 15.2). Among 3,018 surgeons, 1,513 never performed ARE (69,389 beneficiaries), 1,227 performed ARE in <10% of cases (128,258 beneficiaries), and 278 performed ARE in ≥10% of cases (16,619 beneficiaries). After risk-adjustment, survival was significantly lower in SAVR+ARE compared to SAVR recipients: 30-day RMST 28.73 (28.60,28.87) versus 29.35 (29.26,29.45) days (p = 0.013) and 20-year RMST 9.15 (8.96,9.35) vs 9.49 (9.30,9.69) years (p = 0.018). Similarly, beneficiaries treated by frequent-ARE surgeons experienced worse early risk-adjusted survival without any late survival benefit: 30-day RMST 29.19 (29.11,29.27) versus 29.33 (29.25-29.40) days (p = 0.013), 20-year RMST 9.04 (8.90,9.18) versus 9.13 (9.00,9.27) (p = 0.351). Landmark analysis of 1-year survivors showed no late survival difference (p = 0.456 "as-treated" analysis; p = 0.943 "surgeon-preference" analysis). Even among frequent-ARE surgeons, SAVR+ARE was associated with higher 30-day and reduced 20-year RMST relative to SAVR alone. In conclusion, ARE was associated with higher early mortality and no long-term survival advantage compared to SAVR alone (even among frequent-ARE surgeons), as was undergoing surgery by a frequent ARE surgeon. Further studies are required to assess the potential utility of ARE in younger patients, those with small annuli, and those at risk for PPM.

Coronary artery bypass grafting in acute coronary syndromes: modern indications and approaches

PURPOSE OF REVIEW

Acute coronary syndromes (ACS) are a leading cause of morbidity and mortality worldwide, with approximately 1.2 million hospitalizations annually in the U.S. This review aims to explore the contemporary evidence regarding revascularization strategies, including percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG), in ACS patients. It also addresses the unresolved questions concerning the optimal procedural aspects of surgery and antithrombotic therapy for secondary prevention postsurgery.

RECENT FINDINGS

Recent studies highlight that while PCI is generally preferred for its timeliness in high-risk non-ST-elevation ACS (NSTE-ACS) patients, CABG offers a benefit in terms of cardiovascular events in those with multivessel disease, particularly in the presence of diabetes and higher coronary disease complexity. For ST-elevation myocardial infarction (STEMI), CABG is less frequently utilized due to the preference for primary PCI, but it remains crucial for patients with complex anatomy or failed PCI. Furthermore, the optimal timing and type of antiplatelet therapy post-CABG remain controversial, with current evidence supporting the use of dual antiplatelet therapy (DAPT) to reduce ischemic events but necessitating careful management to balance bleeding risks.

SUMMARY

In patients with ACS, the choice between PCI and CABG depends on the complexity of coronary disease and patient comorbidities. CABG is particularly beneficial for multivessel disease in NSTE-ACS and specific STEMI cases where PCI is not feasible. The management of antiplatelet therapy postsurgery requires a nuanced approach to minimize bleeding risks while preventing thrombotic complications. Further randomized clinical trials are needed to solidify these findings and guide clinical practice.

Association between postoperative atrial fibrillation after coronary artery bypass grafting and short-term clinical outcomes

BACKGROUND

Despite advances in prevention and treatment, postoperative atrial fibrillation (POAF) is the most common type of complication undergoing cardiac surgery. This study aimed to identify the relationship between POAF and clinical outcomes after coronary artery bypass graft.

METHODS

In this cross-sectional study, we retrospectively reviewed the medical records of 324 patients who had undergone coronary artery bypass grafting in an intensive care unit between 2010 and 2019 at a tertiary hospital in Korea. Propensity score matching was used to estimate a 1:1 match (without: with POAF) using seven covariates to overcome selection bias. Kaplan-Meier survival analysis and Cox proportional hazards modeling were performed to determine the effect on intensive care unit readmission and length of hospital stay.

RESULTS

After controlling for covariates, 1:1 matching was performed for 91 patients in each group. The occurrence of postoperative atrial fibrillation was found to increase the probability of readmission to the intensive care unit, with a 23% reduced probability of readmission for every 10% increase in left ventricular ejection fraction. Multivariate analysis indicated that postoperative atrial fibrillation, chronic obstructive pulmonary disease as a comorbidity, and preoperative hemoglobin were factors affecting the length of hospitalization after surgery. The Kaplan-Meier survival analysis results indicated that the without POAF group had a higher survival rate than the with POAF group.

CONCLUSIONS

Healthcare professionals should recognize negative factors such as postoperative atrial fibrillation and abnormal hematologic parameters that impact major clinical outcomes in patients and may require closer monitoring before and after coronary artery bypass grafting.

Improvement of the outcome of the saphenous vein graft when connected to the internal thoracic artery

Background

Since 2000, we have been grafting the right coronary artery system (RCAs) using the proximal portion of the right internal thoracic artery (RITA) as the inflow of the saphenous vein graft (SVG) to increase the number of patients undergoing beating heart complete myocardial revascularization.

Methods

From 2000 to 2022, 928 consecutive patients underwent SVG on the RCAs. In 546 patients (58.8%), the inflow was the RITA (I-graft group), and in 382 patients (41.2%), the inflow was the aorta (Ao-graft group). The inclusion criteria were age ≤75 years, ejection fraction >35%, only one SVG per patient, bilateral internal thoracic arteries as a Y-graft on the left system (three-vessel disease, n = 817, 88.0%) or left internal thoracic artery on the left anterior descending artery and RITA + SVG on the RCAs (two-vessel disease, n = 111, 12.0%). Propensity matching identified 306 patients per group. After a median follow-up of 8 (5-10) years, graft patency was assessed by coronary computed tomographic angiography in 132 patients (64 in the I-graft group and 68 in the Ao-graft group).

Results

Early results were similar in both groups. The I-graft group had higher 10-year survival and freedom from main adverse cardiac events (90.0 ± 2.0 vs. 80.6 ± 3.8, p = 0.0162, and 81.3 ± 2.7 vs. 64.7 ± 5.6, p = 0.0206, respectively). When RITA was the inflow, SVG had a higher estimated 10-year patency rate (82.8% ± 6.5 vs. 58.8% ± 7.4, p = 0.0026) and a smaller inner lumen diameter (2.7 ± 0.4 vs. 3.4 ± 0.6 mm, p < 0.0001).

Conclusion

When the inflow is the RITA, SVG grafted to the RCAs (I-graft) may result in a higher patency rate and better outcome than when the inflow is the ascending aorta (Ao-graft). The continuous supply of nitric oxide by RITA may be the cause of the higher patency rate of the I-graft, which can behave like an arterial conduit.

Best treatment option for secondary mitral regurgitation surgery: a network meta-analysis of randomized and non-randomized controlled studies

The objective of this study is to ascertain whether subvalvular papillary muscle repair in conjunction with restrictive mitral valve annuloplasty represents the most efficacious treatment for patients presenting with secondary ischemic mitral regurgitation, as compared to restrictive mitral valve annuloplasty alone and to mitral valve replacement. A network meta-analysis was conducted to investigate outcomes of randomized controlled trials, propensity-matched studies, and observational studies, comparing various treatments for secondary ischemic mitral regurgitation. The average follow-up duration for late mortality was 4.4 years. Coronary artery bypass grafting (CABG) without mitral valve surgery had a late mortality incidence of 3.7%. Restrictive mitral annuloplasty demonstrated a rate of 6.5%, while restrictive mitral annuloplasty + CABG resulted in a rate of 4.1%. Subvalvular papillary muscle repair plus restrictive mitral annuloplasty ± CABG and mitral valve replacement + CABG had rates of 4.4% and 5.1%. SUCRA analysis showed that CABG was the most effective treatment for reducing late mortality (70.0%). This was followed by subvalvular papillary muscle repair plus restrictive mitral annuloplasty with or without CABG (62.4%). The top strategy for decreasing early death, reoperation, and readmission to the hospital for heart failure is subvalvular papillary muscle repair plus restrictive mitral annuloplasty with or without CABG, based on SUCRA probabilities (84.6%, 85.54%, and 86.3%, respectively). Subvalvular papillary muscle repair plus restrictive mitral annuloplasty ± CABG has potential to reduce the risks associated with early mortality, reoperation, and re-hospitalization for heart failure. However, further research is required to substantiate these findings.

Superior Outcomes of Dual-Arterial Coronary Artery Bypass Grafting Are Maintained in the Veterans Health Administration

INTRODUCTION

Controversy surrounds the long-term clinical benefit of coronary artery bypass grafting (CABG) using dual arterial grafts (DAGs) compared to single arterial grafts (SAGs). We investigated outcomes of DAG, using single internal thoracic artery and radial artery (DAG-RA) or bilateral internal thoracic artery grafts (DAG-BITA), compared to SAG, using the left internal thoracic artery and saphenous vein grafts, in the U.S. Veterans Health Administration (VA).

METHODS

We conducted a cross-sectional study of U.S. Veterans undergoing isolated on-pump CABG between 2005 and 2015 at 44 VA medical centers. The primary composite outcome was first occurrence of a major adverse cardiac and cerebrovascular event (MACCE), comprised of death from any cause, myocardial infarction, stroke, or repeat revascularization.

RESULTS

Among 25,969 Veterans undergoing isolated CABG, 1261 (4.9%) underwent DAG (66.8% DAG-RA and 33.2% DAG-BITA). Over a 5-y follow-up, DAG was associated with lower rates of all-cause death (adjusted hazard ratio [AHR] 0.70, 95% confidence interval [CI] 0.58-0.85), MACCE (AHR 0.80, 95% CI 0.71-0.91), and stroke (AHR 0.74, 95% CI 0.57-0.96) versus SAG. DAG-BITA was associated with lower rates of all-cause death (AHR 0.52, 95% CI 0.35-0.77) and MACCE (AHR 0.66, 95% CI 0.51-0.84) than SAG, while DAG-RA was associated with lower rates of all-cause death (AHR 0.79, 95% CI 0.64-0.99).

CONCLUSIONS

In the VA, DAG was associated with improved long-term MACCE outcomes compared to SAG. These results suggest that the practice of DAG in the VA benefits Veterans and should be promoted further.

Race, neighborhood disadvantage, and survival of Medicare beneficiaries after aortic valve replacement and concomitant coronary artery bypass grafting

BACKGROUND

Race, neighborhood disadvantage, and the interaction between these 2 social determinants of health remain poorly understood with regards to survival after aortic valve replacement with concomitant coronary artery bypass grafting (AVR+CABG).

METHODS

Weighted Kaplan-Meier survival analyses and Cox proportional hazards modeling were used to evaluate the association between race, neighborhood disadvantage, and long-term survival in 205,408 Medicare beneficiaries undergoing AVR+CABG from 1999 to 2015. Neighborhood disadvantage was measured using the Area Deprivation Index, a broadly validated ranking of socioeconomic contextual disadvantage.

RESULTS

Self-identified race was 93.9% White and 3.2% Black. Residents of the most disadvantaged quintile of neighborhoods included 12.6% of all White beneficiaries and 40.0% of all Black beneficiaries. Black beneficiaries and residents of the most disadvantaged quintile of neighborhoods had more comorbidities compared with White beneficiaries and residents of the least disadvantaged quintile of neighborhoods, respectively. Increasing neighborhood disadvantage linearly increased the hazard for mortality for Medicare beneficiaries of White but not Black race. Residents of the most and least disadvantaged neighborhood quintiles had weighted median overall survival of 93.0 and 82.1 months, respectively, a significant difference (P < .001 by Cox test for equality of survival curves). Black and White beneficiaries had weighted median overall survival of 93.4 and 90.6 months, respectively, a nonsignificant difference (P = .29 by Cox test for equality of survival curves). A statistically significant interaction between race and neighborhood disadvantage was noted (likelihood ratio test P = .0215) and had implications on whether Black race was associated with survival.

CONCLUSIONS

Increasing neighborhood disadvantage was linearly associated with worse survival after combined AVR+CABG in White but not Black Medicare beneficiaries; race, however, was not independently associated with postoperative survival.

Effect of right internal mammary artery versus radial artery as a second graft vessel in coronary artery bypass grafting on postoperative wound infection in patients: A meta-analysis

Few studies have shown that radial artery (RA), which is used as a secondary arterial graft, offers superior results compared with right internal thoracic artery (RIMA) in coronary artery bypass grafting (CABG). In a meta-analysis of observational studies starting in 2023, we looked at the effect of re-operation on postoperative infection and haemorrhage in CABG with RA vs. RIMA. The electronic database up to October 2023 was examined in the course of the research. Analysis was carried out on the clinical trials of postoperative wound infections and haemorrhage re-surgery. Among 912 trials associated with CABG, we selected 8 trials to be included in the final data analysis. The main results were secondary wound infection and re-operation after surgery. The odds ratios (OR) and confidence intervals (CIs) were computed on the basis of a randomized or fixed-effect model of wound infection and re-operation. Seven trials showed a significant reduction in the risk of wound infection in RA treated as a secondary artery transplant compared with RIMA (OR, 1.60; 95% CI, 1.03, 2.47 p = 0.04); Four trials showed that RIMA was not significantly different from RA in the rate of re-operation for postoperative bleeding (OR, 1.31; 95% CI, 0.60, 2.88 p = 0.50). In CABG, RA is used as a secondary arterial conduit graft to lower the risk of wound infection in CABG patients.

Predictors of long-term stenosis in bicuspid aortic valve repair

OBJECTIVES

The use of modern techniques for bicuspid aortic valve repair has been shown to provide safe and durable results against recurrent regurgitation. However, an emerging body of evidence is indicating that aortic stenosis might be an additional late complication of these procedures. To date, the pathogenesis and clinical impact of aortic stenosis after bicuspid aortic valve repair are poorly understood.

METHODS

A retrospective analysis of 367 patients with bicuspid aortic valve repair was performed to identify predictors of reoperation for stenosis. Bicuspid aortic valve repair was performed using a combination of procedures on the leaflet, annulus, and aortic root.

RESULTS

During a median follow-up of 8 years, reoperation for stenosis was required in 33 patients (9.0%). Freedom from reoperation for stenosis was 100%, 99.6%, 91.7%, and 74.9% at 1, 5, 10, and 15 years, respectively. The following factors were independently associated with reoperation for aortic stenosis: Leaflet or raphe resection with shaving was a protective factor (hazard ratio, 0.34; 95% confidence interval, 0.16-0.71; P = .004), whereas the use of expanded polytetrafluoroethylene for free-edge running suture (hazard ratio, 2.55; 95% confidence interval, 1.16-5.57; P = .019), supracoronary replacement of the ascending aorta in combination with valve repair (hazard ratio, 5.41; 95% confidence interval, 2.11-13.85; P = .001), and the need for a second aortic crossclamp (hazard ratio, 10.95; 95% confidence interval, 2.80-42.80; P = .001) were associated with increased risk of reoperation for aortic stenosis.

CONCLUSIONS

While confirming previous findings, our analysis suggests that the inability to restore leaflet mobility and polytetrafluoroethylene for free-edge running suture are risk factors for stenosis. The so-called ascending phenotypes are probably more prone to stenosis. If the first attempt to repair is unsuccessful, the risk of late reoperation for aortic stenosis is high.

Bilateral internal thoracic artery versus single internal thoracic artery plus radial artery: A double meta-analytic approach

OBJECTIVES

We explored the current evidence on the best second conduit in coronary surgery carrying out a double meta-analysis of propensity score matched or adjusted studies comparing bilateral internal thoracic artery (BITA) versus single internal thoracic artery plus radial artery.

METHODS

PubMed, Embase, and Google Scholar were searched for propensity score matched or adjusted studies comparing BITA versus single internal thoracic artery plus radial artery. The end point was long-term mortality. Two statistical approaches were used: the generic inverse variance method and the pooled meta-analysis of Kaplan-Meier-derived individual patient data.

RESULTS

Twelve matched populations comparing 6450 patients with BITA versus 9428 patients with single internal thoracic artery plus radial artery were included in our meta-analysis. The generic inverse variance method showed a statistically significant survival benefit of the BITA group (hazard ratio, 0.84; 95% CI, 0.74-0.95; P = .04). The Kaplan-Meier estimates of survival at 1, 5, 10, and 15 years of the BITA group were 97.0%, 91.3%, 80.0%, and 68.0%, respectively. The Kaplan-Meier estimates of survival at 1, 5, 10, and 15 years of the single internal thoracic artery plus radial artery group were 97.3%, 91.5%, 79.9%, and 63.9%, respectively. The Kaplan-Meier-derived individual patient data meta-analysis applied to very long follow-up time data, showed that BITA provided a survival benefit after 10 years from surgery (hazard ratio, 0.77; 95% CI, 0.63-0.94; P = .01). No differences in terms of survival between the 2 groups were detected when the analysis was focused on the first 10 years of follow-up (hazard ratio, 0.99; 95% CI, 0.91-1.09; P = .93).

CONCLUSIONS

The present meta-analysis suggests that double internal thoracic artery may provide, compared with single internal thoracic artery plus radial artery, a statistically significant survival advantage after 10 years of follow-up, but not before. VIDEO ABSTRACT.

A Systematic Review of Contemporary Randomized Trials in Cardiothoracic Surgery

Background

This analysis was conducted to characterize contemporary randomized controlled trials (RCTs) in cardiothoracic surgery.

Methods

We selected randomized controlled trials published in the journals with the highest impact factor in medicine, general surgery, and cardiothoracic surgery and published between 2008 and 2020. Trial characteristics as well as measures of reporting and quality were summarized and compared.

Results

Ninety-three trials were included; 44 (47.3%) were prospectively registered and 14 (31.8%) had a discrepancy between the registered and published primary outcome. Most trials (n = 83 [89.1%]) used a superiority design, a composite primary outcome (n = 82 [88.2%]), and a major clinical event as the primary end point (n = 67 [72.0%]). Blinding was used infrequently, and most trials did not control for surgeon experience (n = 74 [79.5%]) or monitor the intervention (n = 90 [96.7%]). Twenty-four (25.8%) trials had high risk of bias. Twenty-one (27.3%) trials were funded by industry. A median 1.62% of patients (interquartile range, 0.00-3.70) crossed over between trial arms. Most trials reported a favorable outcome (n = 53 [58.9%]). For eligible trials, the median fragility index was 2.0 (interquartile range, 0.0-4.0), meaning the change of 2 patient outcomes would render the significant result insignificant. Spin, or distortion in reporting, was identified in 9 of 53 trials (17.0%). The median number of citations was 25 (10-56).

Conclusions

Contemporary trials in cardiothoracic surgery are pragmatic with low rates of loss to follow-up and crossover. Few trials implemented measures to ensure quality of the intervention, and the presence of spin was infrequent.

Are Observational Studies on Distal Radius Fracture Treatment Robust? An E-value Approach to Analysis

BACKGROUND

Reported complication frequencies after distal radius fracture (DRF) treatment vary widely in the literature and are based mostly on observational evidence. Whether that evidence is sufficiently robust to use in practice is controversial. The E-value is an innovative sensitivity analysis that quantitates the robustness of observational evidence against unmeasured confounders, whereby a greater E-value usually implies more robust evidence and vice versa; with DRF complications, this approach can help guide readers to a more confident interpretation of the available evidence.

QUESTIONS/PURPOSES

In this study, we sought (1) to compare the complication frequencies among different DRF treatment modalities, and (2) to evaluate the robustness of these observational studies using the E-value as an index for unmeasured confounding.

METHODS

We searched PubMed, Embase, and SCOPUS for observational studies on the management of DRFs that were published from January 2001 to July 2021 with the last database search performed on July 31, 2021. All articles that compared different DRF treatment modalities with reported complication frequencies were included to accurately capture the quality of the observational studies in research about DRF. Risk ratios (RRs) of the overall complication and major complication risks were calculated for each subgroup comparison: volar plating versus dorsal plating, casting, external fixation, and percutaneous K-wire fixation. The RRs and their corresponding lower limits of the 95% confidence intervals (CIs) were used to derive the E-values. E-values can have a minimum possible value of 1, which signifies that the treatment-outcome association is not strong and can readily be overturned by unmeasured confounders. By contrast, a large E-value means that the observed treatment-outcome association is robust against unmeasured confounders. We averaged RRs and E-values for the effect estimates and lower limits of CIs across studies in each treatment comparison group. We identified 36 comparative observational studies that met the inclusion criteria. Seven studies compared volar with dorsal plating techniques. Volar plating was also compared with casting (eight studies), external fixation (15 studies), and percutaneous K-wire fixation (six studies).

RESULTS

Total and major complication risks did not differ among different DRF treatments. The mean RRs for total and major complications were 1.2 (95% CI 0.4 to 3.9; p = 0.74) and 1.8 (95% CI 0.4 to 11.4; p = 0.52) for the volar versus dorsal plating group; 1.2 (95% CI 0.3 to 11.2; p = 0.87) and 1.5 (95% CI 0.3 to 14.9; p = 0.74) for the volar plating versus casting group; 0.6 (95% CI 0.2 to 2.2; p = 0.33) and 0.8 (95% CI 0.2 to 6.7; p = 0.86) for the volar plating versus external fixation group; and 0.6 (95% CI 0.2 to 2.6; p = 0.47) and 0.7 (95% CI 0.2 to 4.0; p = 0.67) for the volar plating versus K-wire fixation group. The mean E-values for total and major complication frequencies for the between-group comparison ranged from 3.1 to 5.8; these were relatively large in the context of a known complication risk factor, such as high-energy impact (RR 3.2), suggesting a reasonable level of robustness against unmeasured confounding. However, the E-values for lower limits of CIs remained close to 1, which indicates the observed complication frequencies in these studies were likely to have been influenced by unmeasured confounders.

CONCLUSION

Complication frequencies did not differ among different DRF treatment modalities, but the observed complication frequencies from most comparative observational studies were less robust against potential unmeasured confounders. The E-value method, or another type of sensitivity analysis, should be implemented in observational hand surgery research at the individual-study level to facilitate assessment of robustness against potential unmeasured confounders.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Early Re-Exploration versus Conservative Management for Postoperative Bleeding in Stable Patients after Coronary Artery Bypass Grafting: A Propensity Matched Study

BACKGROUND

Postoperative bleeding requiring re-exploration in cardiac surgery has been associated with complications impacting short-term outcomes and perioperative survival. Many aspects of decision-making for re-exploration still remain controversial, especially in hemodynamically stable patients with significant but not acutely cumulating chest drain output. We investigated the impact of re-exploratory surgery on short-term outcomes in a "borderline population" of CABG patients who experienced significant non-acute bleeding, but that were not in critically hemodynamic unstable conditions.

METHODS

A prospectively collected database of 8287 patients undergoing primary isolated elective CABG was retrospectively interrogated. A population of hemodynamically stable patients experiencing significant non-acute or rapidly cumulating bleeding (>1000 mL of blood loss in 12 h, <200 mL per hour in the first 5 h) with normal platelet and coagulation tests was identified (N = 1642). Patients belonging to this group were re-explored (N = 252) or treated conservatively (N = 1390) based on the decision of the consultant surgeon. Clinical outcomes according to the decision-making strategy were compared using a propensity score matching (PSM) approach.

RESULTS

After PSM, reoperated patients exhibited significantly higher overall blood product consumption (88.4% vs. 52.6% for red packed cells, p = 0.001). The reoperated group experienced higher rates of respiratory complications (odds ratio 5.8 [4.29-7.86] with p = 0.001 for prolonged ventilation), prolonged stay in intensive care unit (coefficient 1.66 [0.64-2.67] with p = 0.001) and overall length of stay in hospital (coefficient 2.16 [0.42-3.91] with p = 0.015) when compared to conservative management. Reoperated patients had significantly increased risk of multiorgan failure (odds ratio 4.59 [1.37-15.42] with p = 0.014) and a trend towards increased perioperative mortality (odds ratio 3.12 [1.08-8.99] with p = 0.035).

CONCLUSIONS

Conservative management in hemodynamically stable patients experiencing significant but non-critical or emergency bleeding might be a safe and viable option and might be advantageous in terms of reduction of postoperative morbidities and hospital stay.

Late Clinical Outcomes of Total Arterial Revascularization or Multiple Arterial Grafting Compared to Conventional Single Arterial with Saphenous Vein Grafting for Coronary Surgery

Coronary surgery provides better long-term outcomes than percutaneous coronary intervention. Conventional practice is to use a single arterial conduit supplemented by saphenous vein grafts. The use of multiple arterial revascularization (MAG), or exclusive arterial revascularization (TAR), however, is reported as having improved late survival. Survival is a surrogate for graft failure that may lead to premature death, and improved survival reflects fewer graft failures in the non-conventional strategy groups. The reasons for not using MAG or TAR may be due to perceived technical difficulties, a lack of definitive large-scale randomized evidence, a lack of confidence in arterial conduits, or resources or time constraints. Most people consider radial artery (RA) grafting to be new, with use representing approximately 2-5% worldwide, despite select centers reporting routine use in most patients for decades with improved results. In conclusion, the current body of evidence supports more extensive use of total and multiple arterial revascularization procedures in the absence of contraindications.

Reconstruction Technique Options for Achieving Total Arterial Revascularization and Multiple Arterial Grafting

Ischemic heart disease is the leading cause of morbidity and mortality worldwide and may require coronary revascularization when more severe or symptomatic. Coronary artery bypass grafting (CABG) is the most common cardiac surgical procedure and can be performed with different bypass conduits and anastomotic techniques. Saphenous vein grafts (SVGs) are the most frequently used conduits for CABG, in addition to the left internal thoracic artery. Outcomes with a single internal thoracic artery and SVGs are favorable, and the long-term patency of SVGs may be improved through novel harvesting techniques, preservation methods, and optimal medical therapy. However, increasing evidence points towards the superiority of arterial grafts, especially in the form of multiple arterial grafting (MAG). Nevertheless, the uptake of MAG remains limited and variable, both as a result of technical complexity and a scarcity of conclusive randomized controlled trial evidence. Here, we present an overview of CABG techniques, harvesting methods, and anastomosis types to achieve total arterial revascularization and adopt MAG. We further narratively summarize the available evidence for MAG versus single arterial grafting to date and highlight remaining gaps and questions that require further study to elucidate the role of MAG in CABG.

Angiographic Outcomes for Arterial and Venous Conduits Used in CABG

Coronary artery bypass grafting is the most commonly performed cardiac surgical procedure. Conduit selection is crucial to achieving early optimal outcomes, with graft patency being likely the main driver to long-term survival. We present a review of current evidence on the patency of arterial and venous bypass conduits and of differences in angiographic outcomes.

Coronary artery bypass with single versus multiple arterial grafts in women: A meta-analysis

OBJECTIVE

The study objective was to investigate the impact of multiple arterial grafting on long-term all-cause mortality in women undergoing isolated coronary artery bypass grafting.

METHODS

A comprehensive search was performed to identify observational studies reporting outcomes after coronary artery bypass grafting reported by sex and stratified into multiple arterial grafting versus single arterial grafting strategies. Articles were considered for inclusion if they were written in English and were propensity-matched observational studies. Included studies were then pooled in a meta-analysis performed using the generic inverse variance method. The primary outcome was long-term all-cause mortality. Secondary outcomes were operative mortality and spontaneous myocardial infarction. Meta-regression was used to explore the effects of preoperative and intraoperative variables on the primary outcome.

RESULTS

A total of 6 studies with 32,793 women (25,714 single arterial grafting and 7079 multiple arterial grafting) were included. Women who received multiple arterial grafting had lower long-term mortality (incidence rate ratio, 0.86; 95% confidence interval, 0.76-0.96; P = .007) and spontaneous myocardial infarction (incidence rate ratio, 0.80; 95% confidence interval, 0.68-0.93; P = .003) compared with women who received single arterial grafting, but the difference in mortality disappeared when including only the 3 largest studies. There was no difference between groups in operative mortality (odds ratio, 0.99; 95% confidence interval, 0.84-1.17; P = .91). Meta-regression did not identify any associations with the incidence rate ratio for long-term mortality.

CONCLUSIONS

The use of multiple arterial grafting in women undergoing coronary artery bypass grafting is associated with lower long-term mortality, although the difference is mostly driven by small series. Further studies, including randomized trials, are needed to evaluate the efficacy of multiple arterial grafting in women undergoing coronary artery bypass grafting.

Sensitivity analysis of individual treatment effects: A robust conformal inference approach

We propose a model-free framework for sensitivity analysis of individual treatment effects (ITEs), building upon ideas from conformal inference. For any unit, our procedure reports the Γ-value, a number which quantifies the minimum strength of confounding needed to explain away the evidence for ITE. Our approach rests on the reliable predictive inference of counterfactuals and ITEs in situations where the training data are confounded. Under the marginal sensitivity model of [Z. Tan, J. Am. Stat. Assoc. 101, 1619-1637 (2006)], we characterize the shift between the distribution of the observations and that of the counterfactuals. We first develop a general method for predictive inference of test samples from a shifted distribution; we then leverage this to construct covariate-dependent prediction sets for counterfactuals. No matter the value of the shift, these prediction sets (resp. approximately) achieve marginal coverage if the propensity score is known exactly (resp. estimated). We describe a distinct procedure also attaining coverage, however, conditional on the training data. In the latter case, we prove a sharpness result showing that for certain classes of prediction problems, the prediction intervals cannot possibly be tightened. We verify the validity and performance of the methods via simulation studies and apply them to analyze real datasets.

Single versus multiple arterial grafting in diabetic patients at 10 years: the Arterial Revascularization Trial

AIMS

To evaluate the impact of multiple arterial grafting (MAG) vs. single arterial grafting (SAG) in a post hoc analysis of 10-year outcomes in patients with diabetes mellitus (DM) from the Arterial Revascularization Trial (ART).

METHODS AND RESULTS

The primary endpoint was all-cause mortality and the secondary endpoint was a composite of major adverse cardiac events (MACE) at 10-year follow-up. Patients were stratified by diabetes status (non-DM and DM) and grafting strategy (MAG vs. SAG). A total of 3020 patients were included in the analysis; 716 (23.7%) had DM. Overall, 55.8% non-DM patients received MAG and 44.2% received SAG, while 56.6% DM patients received MAG and 43.4% received SAG. The use of MAG compared with SAG was associated with lower 10-year mortality for both non-DM [17.7 vs. 21.0%, adjusted hazard ratio (HR) 0.87, 95% confidence interval (CI) 0.72-1.06] and DM patients (21.5 vs. 29.9%, adjusted HR 0.65, 95% CI 0.48-0.89; P for interaction = 0.12). For both groups, the rate of 10-year MACE was also lower for MAG vs. SAG. Overall, deep sternal wound infections (DSWIs) were uncommon but more frequent in the MAG vs. SAG group in both non-DM (3.3 vs. 2.1%) and DM patients (7.9 vs. 4.8%). The highest rates of DSWI were in insulin-treated patients receiving MAG (9.6 vs. 6.3%, when compared with SAG).

CONCLUSION

In this post hoc analysis of the ART, MAG was associated with substantially lower mortality rates at 10 years after coronary artery bypass grafting in patients with DM. Patients with DM receiving MAG had a higher incidence of DSWI, especially if insulin dependent.

Effect of coronary artery bypass grafting on quality of life: a meta-analysis of randomized trials

AIMS

We conducted a systematic review and meta-analysis to evaluate temporal trends in quality of life (QoL) after coronary artery bypass grafting (CABG) surgery in randomized clinical trials, and a quantitative comparison from before surgery to up to 5 years after surgery.

METHODS AND RESULTS

We searched MEDLINE, CINAHL, EMBASE, Cochrane Library, and PsycINFO from 2010 to 2020 to identify studies that included the measurement of QoL in patients undergoing CABG. The primary outcome was the Seattle Angina Questionnaire (SAQ), and secondary outcomes were the 36-item Short Form Health Survey (SF-36) and EuroQol Questionnaire (EQ-5D). We pooled the means and the weighted mean differences over the follow-up period. In the meta-analysis, 2586 studies were screened and 18 full-text studies were included. There was a significant trend towards higher QoL scores from before surgery to 1 year post-operatively for the SAQ angina frequency (AF), SAQ QoL, SF-36 physical component (PC), and EQ-5D, whereas the SF-36 mental component (MC) did not improve significantly. The weighted mean differences from before surgery to 1 year after was 24 [95% confidence interval (CI): 21.6-26.4] for the SAQ AF, 31 (95% CI: 27.5-34.6) for the SAQ QoL, 9.8 (95% CI: 7.1-12.8) for the SF-36 PC, 7.1 (95% CI: 4.2-10.0) for the SF-36 MC, and 0.1 (95% CI: 0.06-0.14) for the EQ-5D. There was no evidence of publication bias or small-study effect.

CONCLUSION

CABG had both short- and long-term improvements in disease-specific QoL and generic QoL, with the largest improvement in angina frequency.

Sex differences in outcomes after coronary artery bypass grafting: a pooled analysis of individual patient data

AIMS

Data suggest that women have worse outcomes than men after coronary artery bypass grafting (CABG), but results have been inconsistent across studies. Due to the large differences in baseline characteristics between sexes, suboptimal risk adjustment due to low-quality data may be the reason for the observed differences. To overcome this limitation, we undertook a systematic review and pooled analysis of high-quality individual patient data from large CABG trials to compare the adjusted outcomes of women and men.

METHODS AND RESULTS

The primary outcome was a composite of all-cause mortality, myocardial infarction (MI), stroke, and repeat revascularization (major adverse cardiac and cerebrovascular events, MACCE). The secondary outcome was all-cause mortality. Multivariable mixed-effect Cox regression was used. Four trials involving 13 193 patients (10 479 males; 2714 females) were included. Over 5 years of follow-up, women had a significantly higher risk of MACCE [adjusted hazard ratio (HR) 1.12, 95% confidence interval (CI) 1.04-1.21; P = 0.004] but similar mortality (adjusted HR 1.03, 95% CI 0.94-1.14; P = 0.51) compared to men. Women had higher incidence of MI (adjusted HR 1.30, 95% CI 1.11-1.52) and repeat revascularization (adjusted HR 1.22, 95% CI 1.04-1.43) but not stroke (adjusted HR 1.17, 95% CI 0.90-1.52). The difference in MACCE between sexes was not significant in patients 75 years and older. The use of off-pump surgery and multiple arterial grafting did not modify the difference between sexes.

CONCLUSIONS

Women have worse outcomes than men in the first 5 years after CABG. This difference is not significant in patients aged over 75 years and is not affected by the surgical technique.

Coronary artery bypass grafting in low ejection fraction: state of the art

PURPOSE OF REVIEW

As the number of patients with reduced ejection fraction secondary to ischemic cardiomyopathy (ICM) increases, coronary artery bypass grafting is being used with increasing frequency. In this review, we summarize the different operative considerations in this vulnerable patient population.

RECENT FINDINGS

Preoperative optimization with mechanical circulatory support devices, especially in the setting of hemodynamic instability, can reduce perioperative morbidity and mortality. The advantage of advanced techniques, such as off-pump CABG and multiple arterial grafting remains unclear. Concomitant procedures, such as ablation for atrial fibrillation remain important considerations that should be tailored to the individual patients risk profile.

SUMMARY

Despite improvements in perioperative care of patients undergoing CABG, patients with a reduced ejection fraction remain at elevated risk of major morbidity and mortality. Preoperative optimization and careful selection of intraoperative techniques can lead to improved outcomes.

Radial artery or saphenous vein for Coronary artery bypass grafitng

Coronary artery disease (CAD) is the most common cardiovascular disease worldwide, affecting over 18 million American adults. Coronary artery bypass grafting (CABG) is the standard of care for patients with left main or triple vessel CAD. Historically, the saphenous vein (SV) has been utilized to bypass the majority of the coronary vessels in patients undergoing CABG, but more recent data suggest that the use of the radial artery (RA), rather than the SV, is associated with improved cardiac outcomes and better survival. The aim of this review is to summarize the current literature on the use of RA and SV for CABG in patients with multivessel CAD.

Multiarterial coronary grafting using the radial artery as a second arterial graft: how far does the survival benefit extend?

OBJECTIVES

Despite the 10-year results of the Arterial Revascularization Trial, the controversy regarding the survival benefit of multiarterial grafting (MAG) remains. Our goal was to present our long-term survival data in this propensity-matched observational study.

METHODS

A primary unmatched population of 4303 patients with first-time isolated coronary artery bypass grafts operated on between 2000 and 2018 were included. A total of 1187 post-matched patients were compared with matched controls. Multivariate logistic regression and Cox proportional hazard analyses were undertaken to assess the contribution of MAG and other covariates to the long-term survival of unmatched and propensity-matched populations.

RESULTS

MAG was associated with increased median survival in both the unmatched and the matched groups; difference: 962 and 1459 days, log-rank tests; P = 0.029 and 0.0004, respectively. MAG was associated with a reduced hazard of death in the unmatched as well as in the matched groups: hazard ratio [95% confidence interval (CI)]: 0.72 (0.62-0.83); P < 0.0001 and 0.75 (0.64-0.88); P ≤ 0.0001, respectively. In the matched group, the prosurvival factors were low logistic EuroSCORE, obesity, no intra-aortic balloon pump, an ejection fraction >30%, age 50-69 years, operation by an experienced surgeon, with and without diabetes, on-pump surgery and 3 distal anastomoses. In a cohort of 242 late-presenting patients with reinfarction or recurrent angina, both MAG and control populations were associated with reduced median survival; median (95% CI): MAG: 3026 (1138-3503); control: 3035 (2134-3991), log-rank P = 0.217 with superior patency of the left internal mammary artery but no difference between radial artery and saphenous vein grafts.

CONCLUSIONS

Multiarterial revascularization, especially using the radial artery as a second arterial conduit, is associated with a significant survival benefit and a lack of in-hospital morbidity.

How to build a multi-arterial coronary artery bypass programme: a stepwise approach

Observational evidence shows that the use of multiple arterial grafts (MAG) is associated with longer postoperative survival and improved clinical outcomes. The current European Society of Cardiology/European Association for Cardio-Thoracic Surgery Guidelines on myocardial revascularization recommend the use of MAG in appropriate patients. However, a significant volume-to-outcome relationship exists for MAG, and lack of sufficient experience is associated with increased operative risk. A stepwise approach to building experience with MAG allows successful implementation of this technique into routine coronary surgery practice.

Characteristics of Randomized Clinical Trials in Surgery From 2008 to 2020: A Systematic Review

IMPORTANCE

Randomized clinical trials (RCTs) provide the highest level of evidence to evaluate 2 or more surgical interventions. Surgical RCTs, however, face unique challenges in design and implementation.

OBJECTIVE

To evaluate the design, conduct, and reporting of contemporary surgical RCTs.

EVIDENCE REVIEW

A literature search performed in the 2 journals with the highest impact factor in general medicine as well as 6 key surgical specialties was conducted to identify RCTs published between 2008 and 2020. All RCTs describing a surgical intervention in both experimental and control arms were included. The quality of included data was assessed by establishing an a priori protocol containing all the details to extract. Trial characteristics, fragility index, risk of bias (Cochrane Risk of Bias 2 Tool), pragmatism (Pragmatic Explanatory Continuum Indicator Summary 2 [PRECIS-2]), and reporting bias were assessed.

FINDINGS

A total of 388 trials were identified. Of them, 242 (62.4%) were registered; discrepancies with the published protocol were identified in 81 (33.5%). Most trials used superiority design (329 [84.8%]), and intention-to-treat as primary analysis (221 [56.9%]) and were designed to detect a large treatment effect (50.0%; interquartile range [IQR], 24.7%-63.3%). Only 123 trials (31.7%) used major clinical events as the primary outcome. Most trials (303 [78.1%]) did not control for surgeon experience; only 17 trials (4.4%) assessed the quality of the intervention. The median sample size was 122 patients (IQR, 70-245 patients). The median follow-up was 24 months (IQR, 12.0-32.0 months). Most trials (211 [54.4%]) had some concern of bias and 91 (23.5%) had high risk of bias. The mean (SD) PRECIS-2 score was 3.52 (0.65) and increased significantly over the study period. Most trials (212 [54.6%]) reported a neutral result; reporting bias was identified in 109 of 211 (51.7%). The median fragility index was 3.0 (IQR, 1.0-6.0). Multiplicity was detected in 175 trials (45.1%), and only 35 (20.0%) adjusted for multiple comparisons.

CONCLUSIONS AND RELEVANCE

In this systematic review, the size of contemporary surgical trials was small and the focus was on minor clinical events. Trial registration remained suboptimal and discrepancies with the published protocol and reporting bias were frequent. Few trials controlled for surgeon experience or assessed the quality of the intervention.

Differences in Long-term Outcomes After Coronary Artery Bypass Grafting Using Single vs Multiple Arterial Grafts and the Association With Sex

Importance

Sex-related differences in the outcome of using multiple arterial grafts during coronary artery bypass grafting (CABG) remain uncertain.

Objective

To compare the outcomes of the use of multiple arterial grafts vs a single arterial graft during CABG for women and men.

Design, Setting, and Participants

This statewide cohort study used data from New York's Cardiac Surgery Reporting System and New York's Vital Statistics file on 63 402 patients undergoing CABG from January 1, 2005, to December 31, 2014. Statistical analysis was performed from January 10 to August 20, 2020.

Exposures

Multiple arterial grafting or single arterial grafting.

Main Outcomes and Measures

Mortality, acute myocardial infarction (AMI), stroke, repeated revascularization, major adverse cardiac and cerebrovascular event (composite of mortality, AMI, and stroke), and major adverse cardiac event (composite of mortality, AMI, or repeated revascularization) were compared among propensity-matched patients and stratified by the risk of long-term mortality.

Results

Of the 63 402 patients (48 155 men [76.0%]; mean [SD] age, 69.9 [10.5] years) in the study, women had worse baseline characteristics than men for most of the explored variables. Propensity matching yielded a total of 9512 male pairs and 1860 female pairs. At 7 years of follow-up, mortality was lower among men who underwent multiple arterial grafting (adjusted hazard ratio, 0.80; 95% CI, 0.73-0.87) but not women who underwent multiple arterial grafting (adjusted hazard ratio, 0.99; 95% CI, 0.84-1.15). When stratified by the estimated risk of death, the use of multiple arterial grafts was associated with better survival and a lower rate of a major adverse cardiac event among low-risk, but not high-risk, patients of both sexes, and the risk cutoff was different for men and women.

Conclusions and Relevance

This study suggests that women have a worse preoperative risk profile than men. Multiple arterial grafting is associated with better outcomes among low-risk, but not high-risk, patients, and the risk cutoffs differ between sexes. These data highlight the need for new studies on the outcome of multiple arterial grafts in women.

Tam D, Hare DL, Girardi LN, Biondi‐Zoccai G, E. Fremes S. Angiographic Patency of Coronary Artery Bypass Conduits: A Network Meta-Analysis of Randomized Trials

Background Several randomized trials have compared the patency of coronary artery bypass conduits. All of the published studies, however, have performed pairwise comparisons and a comprehensive evaluation of the patency rates of all conduits has yet to be published. We set out to investigate the angiographic patency rates of all conduits used in coronary bypass surgery by performing a network meta-analysis of the current available randomized evidence. Methods and Results A systematic literature search was conducted for randomized controlled trials comparing the angiographic patency rate of the conventionally harvested saphenous vein, the no-touch saphenous vein, the radial artery (RA), the right internal thoracic artery, or the gastroepiploic artery. The primary outcome was graft occlusion. A total of 4160 studies were retrieved of which 14 were included with 3651 grafts analyzed. The weighted mean angiographic follow-up was 5.1 years. Compared with the conventionally harvested saphenous vein, both the RA (incidence rate ratio [IRR] 0.54; 95% CI, 0.35-0.82) and the no-touch saphenous vein (IRR 0.55; 95% CI, 0.39-0.78) were associated with lower graft occlusion. The RA ranked as the best conduit (rank score for RA 0.87 versus 0.85 for no-touch saphenous vein, 0.23 for right internal thoracic artery, 0.29 for gastroepiploic artery, and 0.25 for the conventionally harvested saphenous vein). Conclusions Compared with the conventionally harvested saphenous vein, only the RA and no-touch saphenous vein grafts are associated with significantly lower graft occlusion rates. The RA ranks as the best conduit. Registration URL: https://www.crd.york.ac.uk/prospero; Unique identifier: CRD42020164492.

Long-term Outcomes Associated With Total Arterial Revascularization vs Non-Total Arterial Revascularization

Importance

The optimal conduits for coronary artery bypass grafting (CABG) remain controversial in multivessel coronary artery disease.

Objective

To compare the long-term clinical outcomes of total arterial revascularization (TAR) vs non-TAR (CABG with at least 1 arterial and 1 saphenous vein graft) in a multicenter population-based study.

Design, Setting, and Participants

This multicenter population-based cohort study using propensity score matching took place from October 2008 to March 2017 in Ontario, Canada, with a mean and maximum follow-up of 4.6 and 9.0 years, respectively. Individuals with primary isolated CABG were identified, with at least 1 arterial graft. Exclusion criteria were individuals from out of province and younger than 18 years. Patients undergoing a cardiac reoperation or those in cardiogenic shock were also excluded because these conditions would potentially bias the surgeon toward not performing TAR. Analysis began April 2019.

Exposures

Total arterial revascularization.

Main Outcomes and Measures

Primary outcome was time to first event of a composite of death, myocardial infarction, stroke, or repeated revascularization (major adverse cardiac and cerebrovascular events). Secondary outcomes included the individual components of the primary outcome.

Results

Of 49 404 individuals with primary isolated CABG, 2433 (4.9%) received TAR, with the total number of bypasses being 2, 3, and 4 or more vessels in 1521 (62.5%), 865 (35.6%), and 47 individuals (1.9%), respectively. The mean (SD) age was 61.2 (10.4) years and 1983 (81.5%) were men. After propensity score matching, 2132 patient pairs were formed, with equal total number of bypasses (mean [SD], 2.4 [0.5]) but with more arterial grafts in the TAR group (mean [SD], 2.4 [0.5] vs 1.2 [0.4]; P < .01). In-hospital death (15 [0.7%] vs 21 [1.0%]; P = .32) did not differ between TAR vs non-TAR groups after propensity score matching. Throughout 8 years, TAR was associated with improved freedom from major adverse cardiac and cerebrovascular events (hazard ratio, 0.78; 95% CI, 0.68-0.89), death (hazard ratio, 0.80; 95% CI, 0.66-0.97), and myocardial infarction (hazard ratio, 0.69; 95% CI, 0.51-0.92). There was no difference in stroke and repeated revascularization.

Conclusions and Relevance

Total arterial revascularization was associated with improved long-term freedom from major adverse cardiac and cerebrovascular events, death, and myocardial infarction and may be the procedure of choice for patients with reasonable life expectancy requiring CABG.

Is the Use of BIMA in CABG Sub-Optimal? A Review of the Current Clinical and Economic Evidence Including Innovative Approaches to the Management of Mediastinitis

Bilateral internal mammary artery (BIMA) in coronary artery bypass grafting (CABG) has traditionally been limited. This review looks at the recent outcome data on BIMA in CABG focusing on the management of risk factors for mediastinitis, one of the potential barriers for more extensive BIMA utilization. A combination of pre-, intra- and postoperative strategies are essential to reduce mediastinitis. Limited data indicate that the incidence of mediastinitis can be reduced using closed incision negative-pressure wound therapy as a part of these strategies with the possibility of offering patients best treatment options by extending BIMA to those with a higher risk of mediastinitis. Recent economic data imply that the technology may challenge the current low uptake of BIMA by reducing the short-term cost differentials between single internal mammary artery and BIMA. Given that most published randomized controlled trials and meta-analyses of observational long-term outcome data favor BIMA, if short-term complications of BIMA including mediastinitis can be controlled adequately, there may be opportunities for more extensive use of BIMA leading to improved long-term outcomes. An ongoing study looking at BIMA in high-risk patients may provide evidence to support the hypothesis that mediastinitis should not be a factor in limiting the use of BIMA in CABG.

Treatment strategies in ischaemic left ventricular dysfunction: a network meta-analysis

OBJECTIVES

The optimal revascularization strategy for patients with ischaemic left ventricular systolic dysfunction (iLVSD) remains controversial. We aimed to compare percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG) and medical therapy (MT) in a network meta-analysis.

METHODS

All randomized controlled trials and observational studies comparing any combination of PCI, CABG and MT in patients with iLVSD were analysed in a frequentist network meta-analysis (generic inverse variance method). Primary outcome was mortality at longest available follow-up. Secondary outcomes were cardiac death, stroke, myocardial infarction (MI) and repeat revascularization (RR).

RESULTS

Twenty-three studies were included (n = 23 633; 4 randomized controlled trials). Compared to CABG, PCI was associated with higher mortality [incidence rate ratio (IRR) 1.32, 95% confidence interval (CI) 1.13-1.53], cardiac death (IRR 1.65, 95% CI 1.18-2.33), MI (IRR 2.18, 95% CI 1.70-2.80) and RR (IRR 3.75, 95% CI 2.89-4.85). Compared to CABG, MT was associated with higher mortality (IRR 1.52, 95% CI 1.26-1.84), cardiac death (IRR 3.83, 95% CI 2.12-6.91), MI (IRR 3.22, 95% CI 1.52-6.79) and RR (IRR 3.37, 95% CI 1.67-6.79). Compared to MT, PCI was associated with lower cardiac death (IRR 0.43, 95% CI 0.24-0.78). CABG ranked as the best revascularization strategy for mortality, cardiac death, MI and RR; MT ranked as the strategy associated with the lowest incidence of stroke. Left ventricular ejection fraction, year of study, use of drug-eluting stents did not affect relative treatment effects.

CONCLUSIONS

CABG appears to be the best therapy for iLVSD, although mainly based on observational data. Definitive randomized controlled trials comparing CABG and PCI in iLVSD are required.

PROSPERO REGISTRATION ID

132414.