Faculty Bibliography

Stroke is a potential complication of treating patients with aortic stenosis via surgical aortic valve replacement (AVR), transcatheter aortic valve replacement (TAVR), and balloon aortic valvuloplasty. Because there are limited and heterogeneous data on the incidence, risk factors, and outcomes of stroke among patients being treated for aortic stenosis, we performed a comprehensive review of the literature. The risk of stroke after AVR in the general population is approximately 1.5%, and the risk is increased (to approximately 2% to 4%) in older and higher-risk patients. Strokes were reported in 1.5% to 6% of patients treated with TAVR, and in the only randomized trial of AVR versus TAVR, there was an increased risk of 30-day strokes (minor and major strokes and transient ischemic attacks) with TAVR (5.5% vs. 2.4%, p = 0.04).

OBJECTIVES: This study sought to evaluate the technical success and clinical outcomes of an adjunctive crossover balloon occlusion technique (CBOT) combined with the 10-F Prostar percutaneous closure device (PCD) on the incidence of vascular and bleeding complications in patients after transfemoral transcatheter aortic valve implantation (TAVI). BACKGROUND: Vascular closure following large-vessel access has most commonly been performed using a surgical cut-down and repair procedure. METHODS: Between November 2008 and September 2010, 58 consecutive patients with severe aortic stenosis underwent TAVI via a retrograde femoral artery approach using the Edwards-SAPIEN transcatheter valve. Among these patients, 56 were treated with a CBOT using the "pre-close" technique and the 10-F Prostar system. The technical success of this new CBOT and the 30-day frequency of clinical events, including all-cause mortality, major vascular complications, and major bleeding (defined according to a modified version of the Valve Academic Research Consortium criteria), were assessed. RESULTS: Successful closure was obtained in all but 3 patients (94.6%). The 30-day frequencies of mortality, major vascular complications, and major bleeding were 7.1%, 14.3%, and 5.4% respectively. No deaths were directly related to access site complications. Fourteen patients (25%) received at least 1 transfusion during the index hospitalization, of which 8 (57.1%) were not related to vascular complications. The mean and median hospital lengths of stay were 7.8 and 6.0 days. CONCLUSIONS: This new percutaneous adjunctive CBOT combined with the Prostar PCD resulted in controlled, safe, and successful percutaneous closure in most patients after TAVI.

BACKGROUND: The use of transcatheter aortic-valve replacement has been shown to reduce mortality among high-risk patients with aortic stenosis who are not candidates for surgical replacement. However, the two procedures have not been compared in a randomized trial involving high-risk patients who are still candidates for surgical replacement. METHODS: At 25 centers, we randomly assigned 699 high-risk patients with severe aortic stenosis to undergo either transcatheter aortic-valve replacement with a balloon-expandable bovine pericardial valve (either a transfemoral or a transapical approach) or surgical replacement. The primary end point was death from any cause at 1 year. The primary hypothesis was that transcatheter replacement is not inferior to surgical replacement. RESULTS: The rates of death from any cause were 3.4% in the transcatheter group and 6.5% in the surgical group at 30 days (P=0.07) and 24.2% and 26.8%, respectively, at 1 year (P=0.44), a reduction of 2.6 percentage points in the transcatheter group (upper limit of the 95% confidence interval, 3.0 percentage points; predefined margin, 7.5 percentage points; P=0.001 for noninferiority). The rates of major stroke were 3.8% in the transcatheter group and 2.1% in the surgical group at 30 days (P=0.20) and 5.1% and 2.4%, respectively, at 1 year (P=0.07). At 30 days, major vascular complications were significantly more frequent with transcatheter replacement (11.0% vs. 3.2%, P<0.001); adverse events that were more frequent after surgical replacement included major bleeding (9.3% vs. 19.5%, P<0.001) and new-onset atrial fibrillation (8.6% vs. 16.0%, P=0.006). More patients undergoing transcatheter replacement had an improvement in symptoms at 30 days, but by 1 year, there was not a significant between-group difference. CONCLUSIONS: In high-risk patients with severe aortic stenosis, transcatheter and surgical procedures for aortic-valve replacement were associated with similar rates of survival at 1 year, although there were important differences in periprocedural risks. (Funded by Edwards Lifesciences; Clinical Trials.gov number, NCT00530894.).

Transcatheter aortic valve implantation (TAVI) with the Cribier-Edwards prosthesis may provide an alternative to conventional aortic valve replacement in high-risk patients with aortic stenosis. Previous studies have indicated that TAVI is feasible in this patient population. Transcatheter implantation of a Cribier-Edwards prosthesis was attempted in 55 patients in a United States Food and Drug Administration-approved prospective observational study. Clinical and echocardiographic outcomes were assessed in hospital and at 30 days, 6 months, and 12 months. Fifty-five patients (55% women, mean age 83 years) with a mean aortic valve area of 0.57 +/- 0.14 cm(2) and a mean logistic European System for Cardiac Operative Risk Evaluation score of 33.5 +/- 17.0% were enrolled. Transcatheter heart valves were implanted successfully in 48 patients (87%). Mean echocardiographic aortic valve area improved from 0.56 +/- 0.14 to 1.6 +/- 0.48 cm(2) after the procedure (p <0.0001). Thirty-day all-cause mortality and major adverse cardiac and cerebrovascular events were 7.3% and 20%, respectively. There were also 7 major procedural vascular complications (12.7%). Mortality and major adverse cardiac and cerebrovascular events increased to 23.6% and 32.7%, respectively, at 1 year, with most late events related to underlying co-morbidities. Mean New York Heart Association functional class improved from 3.22 +/- 0.66 at baseline to 1.50 +/- 0.85 at 1 year follow-up (p <0.001). In conclusion, TAVI in high-risk patients with aortic stenosis was feasible, with sustained clinical benefit at 12 months. Procedural complications and late major adverse cardiac and cerebrovascular events, however, overshadowed the overall clinical benefit of TAVI in this high-risk patient population.

OBJECTIVES: The aim of this study was to evaluate outcomes of patients with moderate- and high-risk acute coronary syndromes (ACS) and multivessel coronary artery disease managed with percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG). BACKGROUND: There is uncertainty about the preferred revascularization strategy for high-risk patients with multivessel disease. METHODS: Among 13,819 moderate- and high-risk ACS patients enrolled in the ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial, 5,627 had multivessel disease (including left anterior descending artery involvement) and were managed by PCI (n = 4,412) or CABG (n = 1,215). Propensity score matching was applied to adjust for differences in baseline clinical and angiographic characteristics, yielding a total of 1,056 patients (528 managed by PCI, and 528 managed by CABG). RESULTS: Propensity-matched patients undergoing CABG had higher 1-month rates of stroke (1.1% vs. 0.0%, p = 0.03) and myocardial infarction (13.3% vs. 8.8%, p = 0.03), received more blood transfusions (40.3% vs. 6.3%, p < 0.0001) and more frequently developed acute renal injury (31.7% vs. 14.2%, p < 0.0001), whereas PCI was associated with higher rates of unplanned revascularization at both 1 month and at 1 year (0.8% vs. 5.2%, p < 0.0001; and 3.8% vs. 16.5%, p < 0.0001, respectively). There were no significant differences between the CABG and PCI groups in 1-month or 1-year mortality (2.5% vs. 2.1%, p = 0.69; and 4.4% vs. 5.7%, p = 0.58, respectively). CONCLUSIONS: In this propensity-matched comparison from the ACUITY trial, moderate- and high-risk patients with ACS and multivessel disease treated with PCI rather than CABG had lower rates of peri-procedural stroke, myocardial infarction, major bleeding, and renal injury, with comparable 1-month and 1-year rates of mortality, but more frequently developed recurrent ischemia requiring repeat revascularization procedures during follow-up. (Comparison of Angiomax Versus Heparin in Acute Coronary Syndromes [ACS]; NCT00093158)

BACKGROUND: The purpose of this study was to compare posttransplantation morbidity and mortality in orthotopic heart transplant recipients bridged to transplant with a left ventricular assist device with nonbridged recipients. To account for potential differences across device types, we stratified bridge-to-transplant recipients by type of ventricular assist device: extracorporeal (EXTRA), paracorporeal (PARA), and intracorporeal (INTRA). METHODS: The United Network for Organ Sharing provided de-identified patient-level data. The study population included 10,668 orthotopic heart transplant recipients aged 18 years old or older and undergoing transplantation between January 1, 2001, and December 31, 2006. Follow-up data were provided through August 3, 2008, with a mean follow-up time of 3.17 +/- 2.15 years (range, 0-8.11 years). The primary outcome was actuarial posttransplant graft survival. Other outcomes of interest included infection, stroke, and dialysis during the transplant hospitalization; primary graft failure at 30 days; transplant hospitalization length of stay; and long-term complications including diabetes mellitus, transplant coronary artery disease, and chronic dialysis. Multivariable Cox proportional hazards regression (backward, P < .15) was used to determine the relationship between groups and overall graft survival, and multivariable logistic regression analysis (backward, P < .15) was used to determine the relationship between groups and secondary outcome measures. RESULTS: In multivariable Cox regression analysis, when compared with the nonbridged group, risk-adjusted greater than 90-day graft survival was diminished among the EXTRA group (hazard ratio = 3.54, 2.28-5.51, P < .001), but not the INTRA group (1.04, 0.719-1.51, P = .834) or the PARA group (1.06, 0.642-1.76, P = .809). There were no significant differences in risk-adjusted graft survival across the 4 groups during the 90-days to 1-year or 1- to 5-year intervals. However, at more than 5 years, risk-adjusted graft survival in the INTRA group (0.389, 0.205-0.738, P = .004) was better than in the nonbridged group. The EXTRA, PARA, and INTRA groups all experienced increased risks of infection. The EXTRA group had increased risks of dialysis, stroke, and primary graft failure at 30 days, whereas neither the PARA nor the INTRA group differed from the nonbridged group. Long-term complications did not differ by group. CONCLUSION: The use of implantable left ventricular assist devices as bridges to transplantation, including both intracorporeal and paracorporeal devices, is not associated with diminished posttransplant survival. However, 90-day survival was diminished in recipients bridged with extracorporeal devices.

OBJECTIVE: Some patients submitted to cardiac surgery have concomitant atrial fibrillation and a previously implanted pacemaker. Because it is unknown if there is any potential for these patients to reassume a regular rate sinus rhythm after ablation of atrial fibrillation, we reviewed the results of all patients with pacemaker enrolled in the Registry of Atrial Fibrillation. MATERIALS: Thirty-six patients were included in this study. Twenty-six had valve disease, seven had coronary disease and three had congenital heart disease. They were submitted concomitantly to ablation of atrial fibrillation using biatrial approaches (seven patients), left sided (27), or right sided (three patients). Thirty-three hospital survivors had a mean follow-up of 18 months, and a maximum of 25 months. RESULTS: At 1 year (n=21), patients' rhythm was sinus non-pacing dependent (52%), sinus pacing-dependent (14%), and atrial fibrillation (14%). At 2 years (n=14), patients' rhythm was sinus non-pacing dependent (57%) and atrial fibrillation (43%). The only factor that may have had impact on the recovery of sinus rhythm at 1 year was the small size of the left atrium (p=0.05). CONCLUSIONS: We conclude that in a significant number of patients, having a pacemaker before surgery does not preclude sinus rhythm recovery after a cardiac operation and ablation for concomitant atrial fibrillation.

BACKGROUND: Recent US and European registries have indicated 30% to 60% of patients with critical valvular aortic stenosis (AS) are not treated surgically, usually due to advanced age and comorbidities. We report on a Food and Drug Administration approved feasibility study of a less invasive transcatheter approach to potentially treat these high-risk patients. METHODS: Between December 2006 and February 18, 2008, 40 patients underwent transcatheter insertion of a balloon expandable stainless-steel stent with an internally mounted three-leaflet equine pericardial valve (Edwards Sapien Transcatheter Heart Valve; Edwards Lifesciences, Irvine, CA) into the aortic annulus using a transapical left ventricular insertion (TA-AVI). Patients were inoperable by conventional surgery, or extremely high risk based on Society of Thoracic Surgeons score greater than 15% or other documented risk factors. RESULTS: All 40 valves were successfully delivered and 35 were successfully seated. Two valves embolized and required open aortic valve replacement (AVR), and one case of severe regurgitation later required AVR. In a further two patients placed on cardiopulmonary support, one valve later embolized and one migrated. There were 7 (17.5%) deaths within 30 days, and a further 2 (5%) deaths before discharge at 42 and 72 days. There were no immediate postoperative strokes after successful deployment. Valve area improved from 0.62 cm(2) (SD of 0.13) to 1.61 cm(2) (SD 0.37) at 30 days (p = or<0.0001), with mean perivalvular regurgitation of 1.19 (SD 0.80). Mean follow-up was 143 days (SD 166 days) with 6 further deaths from comorbid disease, none valve or cardiac related. The Kaplan-Meier survival was 81.8% +/- 6.2% at 1 month and 71.7% +/- 7.7% at 3 months. CONCLUSIONS: Transapical insertion of a balloon expandable stented valve is feasible but carries considerable risk and will be further evaluated in the PARTNER (Placement of AoRTic traNscathetER valve) randomized trial.

OBJECTIVES: To investigate the effect of epicardial fat on surgical atrial fibrillation ablation performance using an in vitro model. Two tissue models were employed to investigate standard penetration and maximal lesion depth performance of bipolar radiofrequency (RF), microwave, and laser energy sources. METHODS: Ventricular veal tissue was utilized in various thicknesses (3 mm, 5 mm, 7 mm, 15 mm). Epicardial fat was modeled by layering porcine fat (1 mm, 2 mm and 4 mm) on moistened tissue. In each group, 8 to 10 lesions were created. Post ablation, tissue samples were sectioned and ablation depth of each myocardial section measured using 1% tetrazolium tetrachloride dye solution. RESULTS: The laser energy source produced nearly 100% transmural lesions in almost all study groups irrespective of myocardium thickness and fat thickness. The microwave device maintained transmurality in all 3-mm and most 5-mm myocardium trials but fell to near zero with all 7-mm myocardium trials. The bipolar RF maintained transmurality only when no fat was applied. In the maximal lesion depth models, the laser was capable of producing lesions >8 mm with no fat and >6 mm with either 2 mm or 4 mm of fat present. The microwave produced lesions in the no fat (>6 mm) and 2-mm (>4 mm) fat group. The bipolar RF produced 83% transmurality with no fat and zero percent transmurality with 2 mm of fat present. CONCLUSIONS: Epicardial fat can severely limit transmurality in energy sources that utilize conductive heating. Laser energy was uniformly superior at producing both transmural and deep lesions irrespective of the presence of fat.