Ahmed A. Abouarab

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

Background Observational studies suggest a survival advantage with bilateral single internal thoracic artery (BITA) versus single internal thoracic artery grafting for coronary surgery, whereas this conclusion is not supported by randomized trials. We hypothesized that this inconsistency is attributed to unmeasured confounders intrinsic to observational studies. To test our hypothesis, we performed a meta‐analysis of the observational literature comparing BITA and single internal thoracic artery, deriving incident rate ratio for mortality at end of follow‐up and at 1 year. We postulated that BITA would not affect 1‐year survival based on the natural history of coronary artery bypass occlusion, so that a difference between groups at 1 year could not be attributed to the intervention. Methods and Results We searched MEDLINE and Pubmed to identify all observational studies comparing the outcome of BITA versus single internal thoracic artery. One‐year and long‐term mortality for BITA and single internal thoracic artery were compared in the propensity‐score–matched (PSM) series, that is, the form of observational evidence less prone to confounders. Thirty‐eight observational studies (174 205 total patients) were selected for final comparison. In the 12 propensity‐score–matched series (34 019 patients), the mortality reduction for BITA was similar at 1 year and at the end of follow‐up (incident rate ratio, 0.70; 95% confidence interval, 0.60–0.82 versus 0.77; 95% confidence interval, 0.70–0.85; P for subgroup difference=0.43). Conclusions Unmeasured confounders, rather than biological superiority, may explain the survival advantage of BITA in observational series.

The radial artery: Results and technical considerations

The radial artery (RA) is a frequently used conduit for coronary artery bypass graft (CABG). We review the results of the use of the RA in CABG patients and discuss the unique technical considerations when using this conduit.

Open repair of descending and thoracoabdominal aortic aneurysms in octogenarians

OBJECTIVEnDespite improved outcomes for open repair of descending thoracic aneurysm (DTA) and thoracoabdominal aortic aneurysm (TAAA), these operations remain challenging in octogenarians. Patients unsuitable for thoracic endovascular aortic repair require open surgery to avoid catastrophic rupture. We analyzed our results for DTA/TAAA repair in these elderly patients.nnnMETHODSnOur institutional aortic database was queried to identify those ≥80xa0years old and thosexa0<80xa0years old undergoing open DTA/TAAA repair. Logistic and Cox regression analyses were used to account for confounders and to identify predictors of perioperative and long-term outcomes.nnnRESULTSnFrom 1997 to 2017, there were 783 patients who underwent open repair of DTA or TAAA; 96 (12.3%) were ≥80xa0years old. Octogenarians were more likely to be female (Pxa0= .018), with chronic pulmonary disease (Pxa0= .012), severe peripheral vascular disease (Pxa0< .001), and hypertension (Pxa0= .025). Degenerative aneurysms were more common among octogenarians (Pxa0< .001), whereas chronic and acute dissections were more common among those younger than 80xa0years (Pxa0< .001 for both). Operative mortality was 5.6% and was not negatively affected by advanced age (<80xa0years, 5.7%; ≥80xa0years, 5.6%; Pxa0= .852). Other than an increased incidence of left recurrent nerve palsy in the younger cohort (<80xa0years, 6.7%; ≥ 80xa0years, 1.0%; Pxa0= .029), there were no significant differences in the incidence of major postoperative complications. Logistic regression modeling showed that age ≥80xa0years was not predictive of operative mortality or postoperative complications. A greater percentage of octogenarians had aortic reconstruction with a clamp and sew strategy (85.4% vs 61.6%; Pxa0< .001), which led to significantly shorter cross-clamp times in this cohort (26.6xa0minutes vs 30.7xa0minutes; Pxa0< .004). In octogenarians, the incidence of major postoperative adverse events was associated with extent II aneurysms (odds ratio, 2.6; Pxa0< .025). Short- and long-term survival was significantly reduced in octogenarians.nnnCONCLUSIONSnIn select octogenarians, open repair of DTA/TAAA can be performed with acceptable risk. A simplified surgical approach may provide the best opportunity for a successful outcome.

Totally endoscopic coronary artery bypass surgery: A meta-analysis of the current evidence

BACKGROUNDnTotally endoscopic coronary artery bypass (TECAB) has emerged as an alternative to other minimally invasive techniques. However, limited TECAB results are available to date. The purpose of this systematic review is to examine the existing literature to give an objective estimate of the outcomes of TECAB using a meta-analytical approach.nnnMETHODSnA comprehensive online review was performed in Ovid MEDLINE®, Ovid EMBASE and The Cochrane Library from 2000 to July 2017. Eligible studies included single arm TECAB studies as well as comparative studies (TECAB vs minimally invasive direct coronary artery bypass (MIDCAB)). Pooled event rates and odds ratios (ORs) for operative mortality, perioperative myocardial infarction (MI), perioperative stroke, graft patency and repeat revascularization were estimated. Single arm and pairwise comparisons were performed.nnnRESULTSnSeventeen single arm TECAB articles (3721 patients, weighted mean follow-up 3.3years) were included. The pooled event rate was 0.80% (95%CI: 0.60-1.2%) for operative mortality, 2.28% (95%CI: 1.7-3%) for perioperative MI, 1.50% (95%CI: 1.1-2.0%) for perioperative stroke, 2.99% (95%CI: 1.6-5.4%) for repeat revascularization and 94.8% (95%CI: 89.3-97.5%) for early graft patency (weighted mean follow-up 10.1months). On pairwise meta-analysis 376 patients (263 TECAB and 113 MIDCAB) were included. No difference in operative mortality (OR=0.25, 95%CI: 0.02-2.83), perioperative MI (OR=3.09, 95%CI: 0.37-26.12) or perioperative stroke (OR=1.33, 95%CI: 0.17-10.26) was found between the two techniques.nnnCONCLUSIONSnTECAB has an acceptably low operative risk and a good early patency rate. The incidence of perioperative MI requires further investigation. The dearth of data comparing TECAB to open approaches compels the need for future comparative trials.

Does a balanced transfusion ratio of plasma to packed red blood cells improve outcomes in both trauma and surgical patients? A meta-analysis of randomized controlled trials and observational studies

BACKGROUNDnThe effect of high transfusion ratios of fresh frozen plasma (FFP): packed red blood cell (RBC) on mortality is still controversial. Observational evidence contradicts a recent randomized controlled trial regarding mortality benefit. This is an updated meta-analysis, including a non-trauma cohort.nnnMETHODSnPatients were grouped into high vs. low based on FFP:RBC ratio. Primary outcomes were 24-h and 30-day/in-hospital mortality. Secondary outcomes were acute respiratory distress syndrome and acute lung injury rates. Random model and leave-one-out-analyses were used.nnnRESULTSnIn 36 studies, lower ratio showed poorer 24-h and 30-day survival (pxa0<xa00.001). In trauma and non-trauma settings, a lower ratio was associated with worse 24-h and 30-day mortality (Pxa0<xa00.001). A ratio of 1:1.5 provided the largest 24-h and 30-day survival benefit (pxa0<xa00.001). The ratio was not associated with ARDS or ALI.nnnCONCLUSIONSnHigh FFP:RBC ratio confers survival benefits in trauma and non-trauma settings, with the highest survival benefit at 1:1.5.

Percutaneous coronary intervention in the elderly: current updates and trends

Ischemic heart disease is the leading cause of death with acute coronary syndrome accounting for more than 30% of causes of mortality in the elderly population. The rate of growth of the older segment of the population has increased exponentially and will become more pronounced in the future. Historically, there has been a paucity of clinical trials investigating the challenges and outcomes of more invasive treatment strategies such as percutaneous coronary intervention (PCI) for that very segment of the population. However, the safety, efficacy, and outcomes of PCI in the older population have started to receive more attention, leading to some changes in their trends. There are several factors that make interventional cardiologists more resistant to direct the elderly to PCI. Most of these challenging factors, such as the complexity of coronary lesions, frailty, hematological and vascular changes, are discussed in this review. In addition. more advanced technologies have been introduced to PCI platform such as secondand thirdgenerations stents, several alternative approaches have been adopted like transradial approach and the usage of bivalirudin instead of heparin and GP IIb/IIIa inhibitor, and several imaging modalities have been optimized to assess patients’ outcome and prognosis more accurately. Several recent studies have shown better results when these strategies are adopted. The most recent recommendations regarding performing PCI in the elderly are also discussed in

Nonbacterial Thrombotic Endocarditis Presenting with Leg Pain and a Left Atrial Mass Lesion

Systemic lupus erythematosus (SLE) is a major cause of nonbacterial thrombotic endocarditis (NBTE) associated with intracardiac sterile vegetations. It is rare for vegetations to present as an atrial tumor. This report describes a 48-year-old female with SLE and antiphospholipid syndrome complicated by recurrent thrombosis on anticoagulation. A large left atrial mass lesion was detected on echocardiography during a work-up for leg burning. Infective endocarditis could not be confirmed, and hence left atrial mass lesion was the most likely diagnosis. The patient was managed surgically and the pathology report revealed fibrin networks in a pattern similar to that of thrombosis, characteristic of NBTE.

Intravenous and Inhaled Milrinone in Adult Cardiac Surgery Patients: A Pairwise and Network Meta-Analysis

OBJECTIVEnTo summarize the evidence on the hemodynamic, echocardiographic, and clinical effects of inhaled and intravenous milrinone (iMil and IvMil) in adult cardiac surgery patients.nnnDESIGNnSystematic review, pairwise and network meta-analysis.nnnSETTINGnMulti-institutional.nnnPARTICIPANTSnAdult cardiac surgery patients.nnnINTERVENTIONSnComparison between iMil and IvMil versus other agents or placebo.nnnMEASUREMENTS AND MAIN RESULTSnThe primary endpoints were mean pulmonary artery pressure (MPAP) and peripheral vascular resistance (PVR). Secondary endpoints included the following: (1) mean arterial pressure, heart rate, and cardiac index (CI); (2) echocardiographic data; and (3) clinical outcomes. Random model, leave-one-out-analysis, and meta-regression were used. Thirty studies (6 iMil and 24 IvMil) were included for a total of 1,438 patients (194 iMil and 521 IvMil). IvMil was associated with a lower MPAP, lower PVR, and higher CI compared to placebo (standardized mean difference [SMD]u202f=u202f-0.22 [95% CIu202f=u202f-0.48 to 0.05], SMDu202f=u202f-0.49 [95% CIu202f=u202f-0.71 to -0.27], and SMDu202f=u202f0.94 [95% CIu202f=u202f0.51 to 1.37]). No difference in any outcome was found between iMil and placebo. At network meta-analysis, significantly lower PVR and shorter hospital length of stay were found for IvMil compared to iMil (SMDu202f=u202f-0.82 [95% CIu202f=u202f-1.53 to -0.10] and SMDu202f=u202f-0.50 [95% CIu202f=u202f-0.95 to -0.05], respectively).nnnCONCLUSIONnThese results support the clinical use of IvMil in cardiac surgery patients. No evidence at present supports the adoption of iMil.

Bilateral internal thoracic artery use in coronary bypass surgery: is there a benefit?

PurposeOver the past three decades, there have been a plethora of retrospective observational data and meta-analyses which support the hypothesis of improved clinical outcomes using bilateral internal thoracic arteries (BITA) when compared to saphenous vein grafts (SVGs). However, recently published results have brought this thinking into doubt. We discuss the existing literature on the subject and attempt to clarify the appropriate use of BITA in coronary artery bypass surgery (CABG).MethodsA review of all existing meta-analyses on BITA was conducted to better understand the utility of BITA in CABG. A review of the largest randomized controlled trials on the subject was then compared to the observational data.ResultsIn all existing meta-analyses, BITA shows a significant advantage over the use of a single internal thoracic artery (SITA) with SVGs. The two largest randomized controlled trials evaluating BITA failed to show a survival advantage and brought into question the complications associated with BITA.ConclusionsAt present, the use of multiple arterial grafts remains a reasonable choice, particularly in young patients, provided that their use does not increase the operative risk. Further evidence currently being collected may lend a definitive answer in the near future.

Editor's Choice – Aortic Re-operation After Replacement of the Proximal Aorta: A Systematic Review and Meta-Analysis

OBJECTIVE/BACKGROUNDnThe aim was to estimate risk of aortic re-operation, and re-operative morbidity and mortality, following replacement of the proximal aorta for aneurysm or dissection.nnnMETHODSnA meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and the Meta-Analysis of Observational Studies in Epidemiology guidelines. A comprehensive literature review was performed to identify all articles reporting aortic re-operation after proximal aortic replacement. The proximal aorta was defined as extending to the origin of the brachiocephalic trunk. The incidence rate for aortic re-operation (IRAR) was calculated, and stratified based on presence/absence of connective tissue disorders, as well as initial surgical indication. Pooled in hospital mortality and post-operative complication rates were estimated.nnnRESULTSnIn total, 7821 patients who underwent proximal aortic replacement from 47 studies were included: 8.3% (nxa0=xa0649) had Marfan syndrome (MS). During a weighted mean follow up of 4.7xa0±xa00.3 years, 11.5% (nxa0=xa0903) underwent aortic re-operation. Mean weighted time between initial surgery and re-operation was 5.2xa0±xa00.2 years. IRAR was 2.4% per person-year (PPY) (confidence interval [CI] 2.1-2.8%). Patients with MFS had a threefold higher IRAR (6.0% PPY, CI 4.1-8.8%) than did patients without a connective tissue disorders (2.3% PPY, CI 1.9-2.7%; pxa0<xa0.001). IRAR was 2.5% PPY (CI 2.1-3.0%) after operation for dissection and 1.3% PPY (CI 0.9-2.0%) after operation for aneurysm (pxa0=xa0.004 for subgroup differences). IRAR proximal and distal to the left subclavian artery was 1.2% PPY (CI 1.0-1.5%) and 1.3% PPY (CI 1.1-1.6%), respectively. The pooled in hospital mortality and complication rates after re-operation were 14.31% (CI 11.28-17.99%) and 18.08% (CI 10.54-29.25%), respectively. On meta-regression, initial operation for dissection was the only significant predictor of aortic re-operation (betaxa0=xa0.030, pxa0=xa0.001).nnnCONCLUSIONnAortic re-operation occurs at a mean rate of 2.4% per person-year in the five years after proximal aortic replacement and is strongly associated with initial operation for dissection.