Faculty Bibliography

BACKGROUND: Although some trials have reported that on-pump coronary artery bypass graft (CABG) surgery may be associated with higher rates of stroke than percutaneous coronary intervention (PCI), whether stroke is more common after off-pump CABG compared with PCI is unknown. We therefore sought to determine whether off-pump CABG is associated with an increased risk of stroke compared with PCI by means of network meta-analysis. METHODS: Randomized controlled trials (RCTs) comparing CABG vs PCI were searched through MEDLINE, EMBASE, Cochrane databases, and proceedings of international meetings. RESULTS: Eighty-three RCTs with 22,729 patients randomized to on-pump CABG (n = 10,957), off-pump CABG (n = 7,119), or PCI (n = 4,653) were analyzed. Thirty-day rates of stroke were significantly lower in patients treated with PCI compared with either off-pump CABG (odds ratio [OR]; 0.39, 95% CI, 0.19-0.83) or on-pump CABG (OR, 0.26; 95% CI, 0.12-0.47). Compared with on-pump CABG, off-pump CABG was associated with significantly lower 30-day risk of stroke (OR, 0.67; 95% CI, 0.41-0.95). However, in sensitivity analyses restricted to high-quality studies, studies with more than either 100 or 1,000 patients, or studies with protocol definition or adjudication of stroke by a clinical events committee, the precision of the point estimate for the 30-day risk of stroke between off-pump vs on-pump CABG was markedly reduced. CONCLUSIONS: Percutaneous coronary intervention is associated with lower 30-day rates of stroke than both off-pump and on-pump CABG. Further studies are required to determine whether the risk of stroke is reduced with off-pump CABG compared with on-pump CABG.

Objectives: Low patency rates of saphenous vein grafts remain a major predicament in surgical revascularization. We examined a novel expandable external support device designed to mitigate causative factors for early and late graft failure. METHODS: For this study, fourteen adult sheep underwent cardiac revascularization using two vein grafts for each; one to the LAD and the other to the obtuse marginal artery. One graft was supported with the device while the other served as a control. Target vessel was alternated between consecutive cases. The animals underwent immediate and late angiography and were then sacrificed for histopathologic evaluation. RESULTS: Of the fourteen animals studied, three died peri-operatively (unrelated to device implanted), and ten survived the follow-up period. Among surviving animals, three grafts were thrombosed and one was occluded, all in the control group (p = 0.043). Quantitative angiographic evaluation revealed no difference between groups in immediate level of graft uniformity, with a coefficient-of-variance (CV%) of 7.39 in control versus 5.07 in the supported grafts, p = 0.082. At 12 weeks, there was a significant non-uniformity in the control grafts versus the supported grafts (CV = 22.12 versus 3.01, p < 0.002). In histopathologic evaluation, mean intimal area of the supported grafts was significantly lower than in the control grafts (11.2 mm^2 versus 23.1 mm^2 p < 0.02). CONCLUSIONS: The expandable SVG external support system was found to be efficacious in reducing SVG's non-uniform dilatation and neointimal formation in an animal model early after CABG. This novel technology may have the potential to improve SVG patency rates after surgical myocardial revascularization.

The Society of Thoracic Surgeons Clinical Practice Guidelines are intended to assist physicians and other health care providers in clinical decision making by describing a range of generally acceptable approaches for the diagnosis, management, or prevention of specific diseases or conditions. These guidelines should not be considered inclusive of all proper methods of care or exclusive of other methods of care reasonably directed at obtaining the same results. Moreover, these guidelines are subject to change over time, without notice. The ultimate judgment regarding the care of a particular patient must be made by the physician in light of the individual circumstances presented by the patient.

Paravalvular leak (PVL) is a frequent complication of transcatheter aortic valve replacement (TAVR) and is seen at a much higher rate after TAVR than after conventional surgical aortic valve replacement. Recent reports indicating that PVL may be correlated with increased late mortality have raised concerns. However, the heterogeneity of methods for assessing and quantifying PVL, and lack of consistency in the timing of such assessments, is a hindrance to understanding its true prevalence, severity, and effect. This literature review is an effort to consolidate current knowledge in this area to better understand the prevalence, progression, and impact of post-TAVR PVL and to help direct future efforts regarding the assessment, prevention, and treatment of this troublesome complication.

Acute kidney injury (AKI) is associated with a poor prognosis after transcatheter aortic valve replacement (TAVR). A paucity of data exists regarding the incidence and effect of AKI after TAVR using the new recommended Valve Academic Research Consortium criteria. At Columbia University Medical Center, 218 TAVR procedures (64.2% transfemoral, 35.8% transapical) were performed from 2008 to July 2011. The creatinine level was evaluated daily until discharge. Using the Valve Academic Research Consortium definitions, the 30-day and 1-year outcomes were compared between patients with significant AKI (AKI stage 2 or 3) and those without significant AKI (AKI stage 0 or 1). Significant AKI occurred in 18 patients (8.3%). Of these 18 patients, 10 (55.6%) had AKI stage 3 and 9 (50%) required dialysis. AKI was associated with a lower baseline mean transvalvular gradient (37.6 +/- 11.4 vs 45.6 +/- 14.8 mm Hg for no AKI, p = 0.03). After TAVR, the AKI group had a greater hemoglobin decrease (3.6 +/- 2.0 vs 2.4 +/- 1.3 g/dl, p = 0.01), greater white blood cell elevation at 72 hours (21.09 +/- 12.99 vs 13.18 +/- 4.82 x 10(3)/mul, p = 0.001), a more severe platelet decrease (118 +/- 40 vs 75 +/- 43 x 10(3)/mul, p <0.0001), and longer hospitalization (10.7 +/- 6.4 vs 7.7 +/- 8.5 days, p <0.001). One stroke (5.6%) occurred in the AKI group compared with 3 (1.5%) in the group without AKI (p = 0.29). The 30-day and 1-year rates of death were significantly greater in the AKI group than in the no-AKI group (44.4% vs 3.0%, hazard ratio 18.1, 95% confidence interval 6.25 to 52.20, p <0.0001; and 55.6% vs 16.0%, hazard ratio 6.32, 95% confidence interval 3.06 to 13.10, p <0.0001, respectively). Periprocedural life-threatening bleeding was the strongest predictor of AKI after TAVR. In conclusion, the occurrence of AKI, as defined by the Valve Academic Research Consortium criteria, is associated with periprocedural complications and a poor prognosis after TAVR.

The treatment of calcified coronary lesions by percutaneous coronary intervention has been shown to be associated with poor outcomes and an increased rate of complications. However, the impact of coronary calcification in patients undergoing coronary artery bypass grafting (CABG) is unknown. A total of 755 patients presenting with acute coronary syndrome in the Acute Catheterization and Urgent Intervention Triage Strategy trial underwent CABG. Patients were divided into 3 groups according to the presence and extent of coronary calcifications (lesion level: severe, moderate, none to mild) as assessed by an independent angiographic core laboratory. Major ischemic and bleeding outcomes were assessed at 30 days and 1 year. Severe calcification was found in 103 patients (13.6%), moderate calcification in 249 patients (33.0%), and none-to-mild calcification in 403 patients (53.4%). The presence of severe calcification compared with moderate or none to mild was associated with a significantly higher unadjusted rate of death (11.8% vs 3.7% vs 4.5%, p = 0.006), death or myocardial infarction (MI; 31.1% vs 19.7% vs 16.4%, p = 0.006), and major adverse cardiac event (MACE; 32.0% vs 22.6% vs 20.8%, p = 0.059) at 1 year. By multivariate analysis, severe calcification (vs nonsevere calcification) was identified as an independent predictor of 1-year MACE (hazard ratio 1.49, 95% confidence interval 1.01 to 2.21, p = 0.04) and death or MI (hazard ratio 1.77, 95% confidence interval 1.18 to 2.66, p = 0.006). In conclusion, the presence of severe coronary calcification was associated with worse outcomes after CABG, including an increased risk of death. The presence of severe coronary calcification was identified as an independent predictor of MACE and death or MI 1 year after CABG.