Faculty Bibliography

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.).

The Ross procedure or pulmonary autograft has been frequently used for surgical treatment of aortic valve disease. One considerable disadvantage of the Ross procedure is the involvement of two valves (aortic and pulmonary) in treatment of single (aortic) valve disease. Both the aortic and pulmonary valves are at risk for future degeneration. Concurrent failure of both valves after a Ross procedure is rare but presents a significant technical challenge when reoperation is necessary. We describe a novel approach to this complication using composite biological valved conduits comprised of stentless bioprosthetic valves and polyester grafts.

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.

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.

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.

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.

Surgical atrial fibrillation ablation (SAFA) has not achieved the efficacy of Cox's original maze procedure, although technical improvements continue to be made. It is possible that biologic factors determine SAFA success. Therefore we examined how patient-specific characteristics affected SAFA success in 353 atrial fibrillation (AF) patients who underwent SAFA at a single institution. Among these, 257 (72.8%) had continuous AF and 96 (27.2%) had intermittent AF. For 297 patients (84.1%) postoperative follow-up was > 3 months. We compared SAFA success in patients whose procedure involved only pulmonary vein isolation with those whose procedure involved extensive lesion sets. Multivariate analysis included AF duration, left atrial size, preoperative atrial flutter, concomitant procedures, lesion sets, and energy source. Early SAFA success was classified as freedom from AF between postoperative months 3 and 6, and intermediate success between postoperative months 6 and 12. Receiver-operating characteristic (ROC) curves and stratum-specific likelihood ratios (SSLR) were generated to compare intermediate failure by left atrial size (LAS) thresholds. SAFA was more successful in the intermittent than the continuous AF group (n = 66, 86% vs n = 165, 71%; P = .014). When pulmonary vein isolation was compared only to more extensive lesion sets, there was no difference in success in the intermittent (34, 91% vs 32, 81%; P = .24) or continuous groups (67, 73% vs. 98, 69%; P = .603). Success for intermittent AF patients was not correlated with variables considered; in continuous AF patients, predictors included presence of concomitant mitral valve repair/replacement (P = .075), decreasing LAS (P = .025) and absence of preoperative atrial flutter (P = .001). In the continuous AF group, ROC curves and corresponding areas under the curve (AUC) were 0.60 (0.50-0.71) for failure at 6 months to 1 year. SSLR analysis generated 2 strata for LAS: < 8 cm with SSLR = 0.87 (0.74-1.0) and < or = 8 cm SSLR = 2.98 (1.07-8.3). In patients with intermittent AF, SAFA achieved acceptable results regardless of tested preoperative and intraoperative variables. In continuous AF, patient-specific characteristics affected success more than intraoperative variables. Failure was more than 3-fold greater in continuous AF patients with an LAS < or = 8 cm. In both patient types, more extensive lesion sets were not shown to improve outcomes. Future improvements in SAFA may depend on pharmacologic and/or surgical substrate modification