Comparison of SYNTAX score strata effects of percutaneous and surgical revascularization trials: A meta-analysis.

OBJECTIVES: The evidence supporting the use of the Synergy Between Percutaneous Coronary Intervention With TAXUS and Cardiac Surgery (SYNTAX) score for risk stratification is controversial. We performed a systematic review and meta-analysis of all the randomized controlled trials comparing percutaneous coronary intervention versus coronary artery bypass grafting that reported their outcomes stratified by SYNTAX score, focusing on between-strata comparisons. METHODS: A systematic review of MEDLINE, EMBASE, Cochrane Library databases was performed. Incidence rate ratios were pooled with a random effect model. Between-group statistical heterogeneity according to accepted SYNTAX score tertiles was computed in the main analysis. Ratios of incidence rate ratios were computed to appraise between-strata effect, as sensitivity analysis. Primary and secondary outcomes were major adverse cardiac and cerebrovascular events and all-cause mortality, respectively. Separate sub-analyses were performed for left main and multivessel disease. RESULTS: From 425 citations, 6 trials were eventually included (8269 patients [4134 percutaneous coronary interventions, 4135 coronary artery bypass graftings]; mean follow-up: 6.2 years [range: 3.8-10]). Overall, percutaneous coronary intervention was associated with a significant increase in major adverse cardiac and cerebrovascular events (incidence rate ratio, 1.39, 95% confidence interval, 1.27-1.51) and nonsignificant increase in all-cause mortality (incidence rate ratio, 1.17, 95% confidence interval, 0.98-1.40). There was no significant statistical heterogeneity of treatment effect by SYNTAX score for major adverse cardiac and cerebrovascular events or mortality (P = .40 and P = .34, respectively). Results were consistent also for patients with left main and multivessel disease (major adverse cardiac and cerebrovascular events: P = .85 in left main, P = .78 in multivessel disease 0.78; mortality: P = .12 in left main; P = .34 in multivessel disease). Results of analysis based on ratios of incidence rate ratios were consistent with the main analysis. CONCLUSIONS: No significant association was found between SYNTAX score and the comparative effectiveness of percutaneous coronary intervention and coronary artery bypass grafting. These findings have implications for clinical practice, future guidelines, and the design of percutaneous coronary intervention versus coronary artery bypass grafting trials.

Spinal cord injury after open and endovascular repair of descending thoracic and thoracoabdominal aortic aneurysms: A meta-analysis.

OBJECTIVE: An inclusive contemporary analysis of spinal cord injury (SCI) rates in patients undergoing aneurysm repair and the factors associated with complications has not been performed. METHODS: Following a systematic literature search, studies from 2008 to 2018 on repair of descending thoracic aneurysm (DTA) and thoracoabdominal aortic aneurysm (TAAA) were pooled in a meta-analysis performed using the generic inverse variance method. The primary outcome was permanent SCI. Secondary outcomes were temporary SCI, operative mortality, long-term mortality, postoperative stroke, and cerebrospinal fluid (CSF) drain-related complications. RESULTS: One-hundred sixty-nine studies (22,634 patients) were included. The pooled rate of permanent SCI was 4.5% (95% confidence interval [CI], 3.8-5.4); 3.5% (95% CI, 1.8-6.7) for DTA and 7.6% (96% CI, 6.2-9.3) for TAAA repair (P for subgroups = .02), 5.7% (95% CI, 4.3-7.5) for open repair and 3.9% (95% CI, 3.1-4.8) for endovascular repair (P for subgroups = .03). Rates for Crawford extents I, II, III, IV, and V aneurysms were 4.0% (95% CI, 3.0-5.0), 15.0% (95% CI, 10.0-22.0), 7.0% (95% CI, 6.0-9.0), 2.0% (95% CI, 2.0-4.0), and 7.0% (95% CI, 2.0-23.0) respectively (P for subgroups <.001). The pooled rates for operative mortality, late mortality at a mean follow-up of 5.0 years, stroke, and temporary SCI were 7.4% (95% CI, 6.1-9.4), 1.0% (95% CI, 0.0-1.0), 4.2% (95% CI, 3.6-4.8), and 3.7% (95% CI, 3.0-4.6), respectively. The pooled rates for severe, moderate, and minor CSF-drain related complications were 5.1% (95% CI, 2.23-11.1), 4.1% (95% CI, 0.6-22.0), and 3.6% (95% CI, 1.2-8.0) respectively. CONCLUSIONS: Despite improvement, both open and endovascular aneurysm repair remain associated with a substantial risk of permanent SCI. The risk is greater for TAAA repair, especially extent II, III, and V.

Sex differences in outcomes following coronary artery bypass grafting: a meta-analysis.

OBJECTIVES: Previous reports have found females are a higher risk of morbidity and mortality following isolated coronary artery bypass grafting (CABG). Here, we describe the differences in outcomes following isolated CABG between males and females. METHODS: Following a systematic literature search, studies reporting sex-related outcomes following isolated CABG were pooled in a meta-analysis performed using the generic inverse variance method. The primary outcome was operative mortality. Secondary outcomes included rates of stroke, repeat revascularization, myocardial infarction, major adverse cardiac events, and late mortality. Subgroup analyses were performed for studies published before and after the year 2000 and for the type of risk adjustment. RESULTS: Eighty-four studies were included with a total of 903 346 patients. Females were at higher risk for operative mortality (odds ratio: 1.77, 95% confidence interval [CI]: 1.64-1.92, P < 0.001). At subgroup analysis, there was no difference in operative or late mortality between studies published prior and after 2000 or between studies using risk adjustment. Females were at a higher risk of late mortality (incidence rate ratio [IRR]: 1.16, 95% CI: 1.06-1.26, P < 0.001), major adverse cardiac events (IRR: 1.40, 95% CI: 1.19-1.66, P < 0.001), myocardial infarction (IRR: 1.28, 95% CI: 1.13-1.45, P < 0.001) and stroke (IRR: 1.31, 95% CI: 1.15-1.51, P > 0.001) but not repeat revascularization (IRR: 0.99, 95% CI: 0.76-1.29, P = 0.95). The use of the off-pump technique or multiple arterial grafts was not associated with the primary outcome. CONCLUSIONS: Females undergoing CABG are at higher risk for operative and late mortality as well as postoperative events including major adverse cardiac events, myocardial infarction and stroke. PROSPERO REGISTRATION: CRD42020187556.

Effects of Experimental Interventions to Improve the Biomedical Peer-Review Process: A Systematic Review and Meta-Analysis.

Background Quality of the peer-review process has been tested only in small studies. We describe and summarize the randomized trials that investigated interventions aimed at improving peer-review process of biomedical manuscripts. Methods and Results All randomized trials comparing different peer-review interventions at author-, reviewer-, and/or editor-level were included. Differences between traditional and intervention-modified peer-review processes were pooled as standardized mean difference (SMD) in quality based on the definitions used in the individual studies. Main outcomes assessed were quality and duration of the peer-review process. Five-hundred and seventy-five studies were retrieved, eventually yielding 24 randomized trials. Eight studies evaluated the effect of interventions at author-level, 16 at reviewer-level, and 3 at editor-level. Three studies investigated interventions at multiple levels. The effects of the interventions were reported as mean change in review quality, duration of the peer-review process, acceptance/rejection rate, manuscript quality, and number of errors detected in 13, 11, 5, 4, and 3 studies, respectively. At network meta-analysis, reviewer-level interventions were associated with a significant improvement in review quality (SMD, 0.20 [0.06 to 0.33]), at the cost of increased duration of the review process (SMD, 0.15 [0.01 to 0.29]), except for reviewer blinding. Author- and editor-level interventions did not significantly impact peer-review quality and duration (respectively, SMD, 0.17 [-0.16 to 0.51] and SMD, 0.19 [-0.40 to 0.79] for quality, and SMD, 0.17 [-0.16 to 0.51] and SMD, 0.19 [-0.40 to 0.79] for duration). Conclusions Modifications of the traditional peer-review process at reviewer-level are associated with improved quality, at the price of longer duration. Further studies are needed. Registration URL: https://www.crd.york.ac.uk/prospero; Unique identifier: CRD42020187910.

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.

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.

Publication of cardiac surgery research papers in top cardiovascular journals.

BACKGROUND AND AIM: To evaluate the publication rate of articles related to cardiac surgery in the four main cardiovascular journals over the last 5 years. METHODS: A bibliometric review of all full-length articles published between January 2014 and March 2020 in the top four cardiovascular journals (Circulation, European Heart Journal (EHJ), Journal of the American College of Cardiology (JACC), and JAMA Cardiology) was conducted. For each eligible article in the four journals, the journal of publication, study design, area of interest, country of origin, and type of intervention tested (for cardiac surgery and interventional cardiology studies) were extracted. The affiliations of all editorial board members were identified from journal websites or from online searches and recorded as from cardiac surgery, cardiology, or another discipline. Correlations between variables were evaluated. RESULTS: A total of 4835 articles were reviewed. Cardiac surgery studies amounted to 6.2% (104) of total research publications in JACC, 4.4% (74) in Circulation, 3.6% (13) in JAMA Cardiology, and 2.0% (22) in EHJ (P < .001). The percentage of cardiac surgery publications was significantly less than interventional cardiology publications (P < .001). CONCLUSIONS: Cardiac surgery studies represent only a small minority of the articles published in the top cardiovascular journals over the last 5 years, with significant differences between individual journals. Cardiac surgery studies were more often observational and this may constitute one important reason for their under-representation.

Overall and Cause-Specific Mortality in Randomized Clinical Trials Comparing Percutaneous Interventions With Coronary Bypass Surgery: A Meta-analysis.

Importance: Mortality is a common outcome in trials comparing percutaneous coronary intervention (PCI) with coronary artery bypass grafting (CABG). Controversy exists regarding whether all-cause mortality or cardiac mortality is preferred as a study end point, because noncardiac mortality should be unrelated to the treatment. Objective: To evaluate the difference in all-cause and cause-specific mortality in randomized clinical trials (RCTs) comparing PCI with CABG for the treatment of patients with coronary artery disease. Data Sources: MEDLINE (1946 to the present), Embase (1974 to the present), and the Cochrane Library (1992 to the present) databases were searched on November 24, 2019. Reference lists of included articles were also searched, and additional studies were included if appropriate. Study Selection: Articles were considered for inclusion if they were in English, were RCTs comparing PCI with drug-eluting or bare-metal stents and CABG for the treatment of coronary artery disease, and reported mortality and/or cause-specific mortality. Trials of PCI involving angioplasty without stenting were excluded. For each included trial, the publication with the longest follow-up duration for each outcome was selected. Data Extraction and Synthesis: For data extraction, all studies were reviewed by 2 independent investigators, and disagreements were resolved by a third investigator in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline. Data were pooled using fixed- and random-effects models. Main Outcomes and Measures: The primary outcomes were all-cause and cause-specific (cardiac vs noncardiac) mortality. Subgroup analyses were performed for PCI trials using drug-eluting vs bare-metal stents and for trials involving patients with left main disease. Results: Twenty-three unique trials were included involving 13 620 unique patients (6829 undergoing PCI and 6791 undergoing CABG; men, 39.9%-99.0% of study populations; mean age range, 60.0-71.0 years). The weighted mean (SD) follow-up was 5.3 (3.6) years. Compared with CABG, PCI was associated with a higher rate of all-cause (incidence rate ratio, 1.17; 95% CI, 1.05-1.29) and cardiac (incidence rate ratio, 1.24; 95% CI, 1.05-1.45) mortality but also noncardiac mortality (incidence rate ratio, 1.19; 95% CI, 1.00-1.41). Conclusions and Relevance: Percutaneous coronary intervention was associated with higher all-cause, cardiac, and noncardiac mortality compared with CABG at 5 years. The significantly higher noncardiac mortality associated with PCI suggests that even noncardiac deaths after PCI may be procedure related and supports the use of all-cause mortality as the end point for myocardial revascularization trials.

Robustness of the Comparative Observational Evidence Supporting Class I and II Cardiac Surgery Procedures.

Background Current cardiac surgery guidelines give Class I and II recommendations to valve-sparing root replacement over the Bentall procedure, mitral valve (MV) repair over replacement, and multiple arterial grafting with bilateral internal thoracic artery based on observational evidence. We evaluated the robustness of the observational studies supporting these recommendations using the E value, an index of unmeasured confounding. Methods and Results Observational studies cited in the guidelines and in the 3 largest meta-analyses comparing the procedures were evaluated for statistically significant effect measures. Two E values were calculated: 1 for the effect-size estimate and 1 for the lower limit of the 95% CI. Thirty-one observational studies were identified, and E values were computed for 75 effect estimates. The observed effect estimates for improved clinical outcomes with valve-sparing root replacement versus the Bentall procedure, MV repair versus replacement, and grafting with bilateral internal thoracic artery versus single internal thoracic artery could be explained by an unmeasured confounder that was associated with both the treatment and outcome by a risk ratio of more than 16.77, 4.32, and 3.14, respectively. For MV repair versus replacement and grafting with bilateral internal thoracic artery versus single internal thoracic artery, the average E values were lower than the effect sizes of the other measured confounders in 33.3% and 60.9% of the studies, respectively. For valve-sparing root replacement versus the Bentall procedure, no study reported effect sizes for associations of other covariates with outcomes. Conclusions The E values for observational evidence supporting the use of valve-sparing root replacement, MV repair, and grafting with bilateral internal thoracic artery over the Bentall procedure, MV replacement, and grafting with single internal thoracic artery are relatively low. This suggests that small-to-moderate unmeasured confounding could explain most of the observed associations for these procedures.

Open Repair of Descending Thoracic and Thoracoabdominal Aortic Aneurysms: A Meta-Analysis.

BACKGROUND: Contemporary outcomes of open repair of thoracoabdominal aortic aneurysms (TAAAs) and descending thoracic aortic aneurysms (DTAs) have not been analyzed in an inclusive meta-analysis. METHODS: After a systematic literature search, studies from 2008 to 2018 reporting outcomes of open repair of DTAs or TAAAs were pooled in a single-arm meta-analysis performed using the generic inverse variance method. Primary outcome was operative mortality. Secondary outcomes were late mortality, postoperative stroke, permanent and temporary spinal cord injury, renal failure, respiratory failure, and myocardial infarction. RESULTS: Fifty-four studies with 12,245 patients were included. Pooled operative mortality for open repair was 10.4% (95% confidence interval [CI], 8.3-12.8): 6.6% (95% CI, 3.7-11.6) for DTA and 10.5% (95% CI, 7.5-14.5) for TAAA. Pooled incidence rate of late mortality was 0.6% (95% CI, 0.5-0.8) per person-year. Pooled rates for postoperative outcomes were 4.9% (95% CI, 3.9-6.1) for stroke; 5.7% (95% CI, 4.3-7.5) and 3.0% (95% CI, 2.1-4.2) for permanent and temporary spinal cord injury, respectively; 13.2% (95% CI, 9.9-17.3) for renal failure; 23.3% (95% CI, 17.5-30.4) for respiratory failure; and 2.7% (95% CI, 1.8-4.1) for myocardial infarction. At metaregression, year of publication, use of the clamp-and-sew technique, and use of the cerebrospinal fluid drain were associated with lower operative mortality. Ruptured aneurysms were associated with higher operative mortality. CONCLUSIONS: Despite improvement, open repair of DTAs and TAAAs continues to be associated with a considerable risk for operative death and perioperative complications. Use of the cerebrospinal fluid drain is associated with better outcomes.

Diagnostic dilemma of perioperative myocardial infarction after coronary artery bypass grafting: A review.

Coronary artery bypass grafting (CABG) is one of the most commonly performed cardiac procedures in the United States (US) and Europe. In the US, perioperative morbidity and mortality related to CABG are below 5%. One of the most significant complications following CABG, however, is perioperative myocardial infarction (PMI). Cardiac biomarkers, intra- and post-operative echocardiography, and electrocardiography are routinely used to monitor for evidence of PMI. In this review, we seek to summarize how each of these modalities is used in the clinical setting to differentiate PMI from expected procedure-related changes, and how these findings impact patients' outcomes. We conclude that while no perfect diagnostic test for the detection of clinically meaningful PMI exists, using a combination of existing modalities with knowledge of expected post-procedure changes allows for early and reliable detection. Future development is needed to create more sensitive and specific modalities for the detection of PMI in patients undergoing CABG.

Effect of Concomitant Coronary Artery Bypass Grafting on Outcomes of Ascending Aorta Replacement.

BACKGROUND: Ascending aorta replacement can be performed safely in high-volume centers. What remains unknown is whether concomitant coronary revascularization with bypass grafting affects postoperative outcomes. METHODS: This study retrospectively reviewed a prospectively maintained institutional database for patients who underwent ascending aorta replacement (AAR) during the period from 1997 to 2018. Patients were stratified into AAR alone (AAR) vs AAR and coronary artery bypass graft (AAR with CABG), further categorized as 1 or more than 1 CABG. Aortic dissection and root replacement cases were excluded. The primary end point consisted of major adverse events (MAE), including operative mortality, perioperative myocardial infarction, stroke, need for tracheostomy, and need for dialysis. Secondary end points were operative mortality, each MAE component, and late survival. RESULTS: A total of 951 patients were included in the analysis; 725 (76.2%) underwent isolated AAR, and 226 (23.8%) underwent AAR with CABG. Operative mortality was similar across the 2 groups (1.8% for AAR with CABG and 0.8% for AAR; P = .40). The unadjusted incidence of MAE was higher in the AAR with CABG group (5.8% vs 1.9%; P = .005).). On multivariable analysis, the performance of 1 CABG (odds ratio [OR], 1.90; 95% confidence interval [CI], 0.67 to 5.33; P = .23) and more than 1 CABG (OR, 2.65; 95% CI, 0.93 to 7.53; P = .07) was not associated with higher rates of MAE. Preoperative pulmonary dysfunction (OR, 2.51; 95% CI, 1.07 to 5.85; P = .03) was the only independent predictor of MAE. CONCLUSIONS: In patients undergoing concomitant CABG with AAR, the performance of concomitant CABG is not associated with an increased risk of MAE.

Characteristics, results, and reporting of contemporary surgical trials: A systematic review and analysis.

INTRODUCTION: The complexities and risks inherent to the field of surgery and surgical interventions present unique challenges to the design and analysis of surgical randomized controlled trials (RCT). Prior studies have investigated the practical and methodologic challenges posed by surgical RCTs. To date, however, a comprehensive analysis of the contemporary literature across multiple surgical subspecialties does not exist. In this descriptive analysis, we set out to characterize surgical RCTs over the past 10 years across six major surgical specialties. METHODS AND ANALYSIS: A literature search by a medical librarian will be performed to identify all surgical randomized clinical trials published between January 2009 and December 2019 in the two journals with the highest impact factor for six surgical specialties as well as two large general medicine journals. Two reviewers will independently screen the citations retrieved from the literature search and extract data according to a previously described protocol via a pre-defined data collection form. Categorical variables will be reported as counts and percentages. Following assessment of normality, continuous variables will be reported as mean (standard deviation) or median (inter-quartile range). Based on normality of data, independent t-test or the Mann-Whitney U test will be used to compare continuous variables and chi-square and Fisher's exact tests to compare categorical variables. Comparisons across multiple sets will be performed using ANOVA or Kruskak-Wallis tests. Two-sided significance testing will be used and a p-value <0.05 will be considered significant without adjustment for multiple testing. All analyses will be performed using SPSS version 24 and R within RStudio. PROSPERO (ID number: 162797). ETHICS AND DISSEMINATION: There are no ethical concerns directly pertinent to this systematic review. The retrieved data will be made available upon request. The study will be written in English and submitted for publication in a peer-reviewed journal.

Comparison of the effects of hemodialysis and hemodiafiltration on left ventricular hypertrophy in end-stage renal disease patients: A systematic review and meta-analysis.

Whether hemodiafiltration (HDF) is better than conventional hemodialysis (HD) in improving left ventricular hypertrophy (LVH), defined as reduction of the left ventricular mass index (LVMi) and increasing the ejection fraction (EF), is unclear. A systematic literature search was performed. Primary outcome was the mean difference between pre- and post-procedural LVMi. Secondary outcome was the mean difference in EF. Seven studies with a total of 845 patients were included. The pooled mean difference between pre-and post-procedural LVMi was -8.0 g/m2 (95% confidence interval [CI] -13.1, -2.8). On subgroup analysis, the mean differences between pre- and post-procedural LVMi for HD and HDF were -6.7 g/m2 (95% CI -14.5, 1.1) and -9.3 g/m2 (95% CI -16.3, -2.3), respectively (P for subgroups = .62). Pooled mean difference between pre- and post-procedural EF was 2.4% (95% CI -1.8, 6.5). On subgroup analysis, the mean differences between pre- and post-procedural EF for HD and HDF were 3.6% (95% CI -2.7, 9.8) and 2.0% (95% CI 2.9, 6.8), respectively (P for subgroups = .68). On meta-regression, age (Beta -0.35 ± 0.05, P < .001) and longer dialysis duration (Beta -0.12 ± 0.02, P < .001) were associated with lower mean difference between pre-and post-procedural EF. No significant effects on changes in LVMi and EF were observed with HDF compared with conventional HD.

The translation of surgical animal models to human clinical research: A cross-sectional study.

BACKGROUND: Surgical animal models are used in pre-clinical scientific studies. To date there has not been an analysis of how effective these data are when translated to human/clinical research. In this retrospective review, we evaluate the impact of studies using surgical animal models on human/clinical research through study-level analysis of citations. METHODS: The top two ranking clinical journals based on impact factor for the top ten surgical specialties were identified and a search was run on PubMed to identify studies using surgical animal models published in the years 2007 and 2008. The translation to human/clinical research of each study was evaluated by analyzing the frequency of citation in human studies over the ten years following publication. Regression was used to identify predictors of citation in human/clinical research. RESULTS: 411 animal studies using surgical models were identified. Over the course of the 10 years following publication the original animal studies were cited 6063 times, with 1300 (21.4%) citations in human/clinical studies and 4763 (78.6%) in animal/basic science studies. The median number of citations in human/clinical research was 1 (IQR 0-5). Regression showed an association between citation in human/clinical research and the use of porcine models and the specialties of general surgery, oral and maxillofacial surgery, orthopedic surgery, transplant, and plastic surgery. CONCLUSION: The use of animal models in surgical research shows poor translation to human/clinical research. Alternative surgical models should urgently be explored.

Effect of atrial pacing on post-operative atrial fibrillation following coronary artery bypass grafting: Pairwise and network meta-analyses.

BACKGROUND: To determine the effect of atrial pacing on the rate of post-operative atrial fibrillation (POAF) following coronary artery bypass grafting. METHODS: After a systematic literature search, randomized clinical trials (RCTs) comparing any combination of no pacing (NP), bi-atrial (BiA) pacing, left-atrial (LA) pacing and right-atrial (RA) pacing were included. Pairwise and network meta-analyses were performed using the generic inverse variance method. The primary outcome was POAF incidence. Secondary outcomes were postoperative bleeding, infection, and operative mortality. Leave-one-out and meta-regression were done. RESULTS: Fourteen RCTs were included with a total of 1727 patients. Compared with NP, any form of atrial pacing was significantly associated with lower incidence of POAF (odds ratio [OR]: 0.49; 95% confidence interval [CI]: 0.35-0.69). BiA pacing was associated with the larger risk reduction (OR: 0.36; 95% CI: 0.20-0.64 vs. 0.59; 95% CI: 0.34-1.02 for LA and 0.64; 95% CI: 0.38-1.07 for RA). Secondary outcomes were similar between the no pacing and pacing groups. On meta-regression, age and the use of continuous monitoring were associated with lower reduction of the incidence of POAF. In the network meta-analysis, BiA pacing ranked the best strategy for the prevention of POAF (OR: 0.34; 95% CI: 0.21-0.55). CONCLUSIONS: Compared to other pacing modalities, BiA pacing is associated with lower rates of POAF following CABG.

Intraoperative graft flow profiles in coronary artery bypass surgery: A meta-analysis.

BACKGROUND: Conduits used in coronary artery bypass artery grafting (CABG) have different properties and flow profiles. We compared intraoperative mean graft flow (MGF) between arterial and venous conduits, off-pump CABG (OPCABG) and on-pump CABG (ONCABG) procedures, skeletonized and pedicled internal mammary artery (IMA) grafts, and pulsatility index (PI) between OPCABG and ONCABG, in pairwise meta-analyses. METHODS: Following a systematic literature search, all studies comparing MGF in arterial and venous grafts, were included. The primary endpoint was comparison of pooled MGF between arterial and venous grafts. Secondary endpoints were comparisons of pooled MGF in OPCABG vs ONCABG, anastomosed skeletonized vs pedicled IMA grafts, free skeletonized vs pedicled IMA grafts and PI in OPCABG versus ONCABG. RESULTS: A total of 25 studies with 4443 patients were included. Compared with venous grafts, arterial grafts had lower MGF (standardized mean difference [SMD], -0.28; 95% confidence interval [CI, -0.34; -0.22]; P < .001). OPCABG was associated with significantly lower MGF compared to ONCABG (SMD, -0.29; 95%CI, -0.50; -0.08]; P = .01). No differences were found in MGF between skeletonized vs pedicled IMA after anastomosis (SMD, 0.32; 95%CI [-0.08; 0.71]; P = .11) or in free flow (SMD, 0.76; 95%CI [-0.14; 1.65]; P = .10). No difference was found in PI between OPCABG and ONCABG. At meta-regression, age was associated with higher MGF, while OPCABG was associated with lower MGF. CONCLUSIONS: Intraoperative flow of venous conduits is higher than that of arterial grafts. Compared to OPCABG surgery, graft flow is higher in ONCABG. In skeletonized and pedicled IMA conduits, no difference in flow profiles was found.

Changes in the socioeconomic status of patients receiving TAVR in New York State.

BACKGROUND: When transcatheter aortic valve replacement (TAVR) was first approved by the Food and Drug Administration in October 2011, it was an innovative treatment with limited accessibility. However, over the past few years, TAVR has become standard of care in patients with aortic stenosis. The effect of socioeconomic status (SES) on this transition of use of TAVR is unknown. METHOD: Using the New York state department Statewide Planning and Research Cooperative System database, we compared baseline patient characteristics and facilities in low-income areas and high-income areas. Trends in residential SES of patients undergoing TAVR were examined over time and assessed with a Poisson regression and Cochran Armitage trend tests. RESULT: From October 2011 and 2012 to December 2016, we found that the numbers of TAVR procedures performed among patients from both low (187-1150 in 2016, P < .001) and high (227-1160, P < .001) income areas increased over time. The proportion of TAVR procedures performed in patients from low-income areas increased over time, while those in high-income areas decreased (from 45.2% in 2011 and 2012 to 49.8% in 2016 for low-income and from 54.8%-50.2% for high-income, P = .009). CONCLUSION: In the case of TAVR in New York State, when the innovative treatment was introduced in the clinical practice, there were initial SES-based disparities in access to the procedure. However, these disparities resolved over time, probably due to the broader diffusion of the technique.