Faculty Bibliography

Atrial fibrillation (AF) is associated with worse outcomes in many cardiovascular diseases. There are few data examining pacemaker implantation rates and indications in patients with AF who undergo transcatheter aortic valve replacement (TAVR). To examine the impact of AF on the incidence of and indications for pacemakers in patients undergoing TAVR, we evaluated data of 1723 patients without pre-existing pacemakers who underwent TAVR in the Placement of AoRTic TraNscathetER Valve (PARTNER) trial. Permanent pacemaker implantation rates and indications were compared in groups based on baseline and discharge heart rhythm: sinus rhythm (SR) vs. AF. 1211 patients manifested SR at baseline/SR at discharge (SR/SR), 105 SR baseline/AF discharge (SR/AF), and 407 AF baseline/AF discharge (AF/AF). Patients who developed and were discharged with AF (SR/AF) had the highest rates of pacemaker implantation at 30 days (13.7% SR/AF vs. 5.4% SR/SR, p=0.0008 and 5.9% AF/AF, p=0.008) and 1 year (17.7% SR/AF vs. 7.1% SR/SR, p=0.0002 and 8.1% AF/AF, p=0.0034). Conversion from SR to AF by discharge was an independent predictor of increased pacemaker implantation at 30 days (HR 2.19 vs. SR/SR, 95% CI 1.23-3.93, p=0.008) and 1 year (HR 1.91 vs. SR/SR, 95% CI 1.33-3.80). Pacemaker indications differed between groups, with relatively more implanted in the AF groups for sick sinus syndrome (SSS) versus AV block. In conclusion, conversion to AF is an independent predictor of permanent pacemaker implantation in TAVR patients. Indications differ depending on heart rhythm, with patients in AF manifesting clinically significant tachy-brady syndrome versus AV block.

Background: Patients with severe aortic stenosis in the setting of low gradient and preserved left ventricular ejection fraction (LVEF) remain an area of clinical uncertainty. Methods: Retrospective chart review identified 209 patients who underwent transcatheter aortic valve replacement (TAVR) between September 2014 and September 2015. Of these patients, 3 (1.4%) were excluded due to procedural indication other than severe aortic stenosis and 41 (20%) were excluded due to reduced LVEF (<50%). Of the remaining 165 patients with aortic valve area <1 cm2, 77 (47%) had either a peak velocity <4.0 m2 or mean gradient <40 mmHg (LG group) and 88 (53%) had both peak velocity >4.0 m2 and mean gradient >40 mmHg (HG group) across the AV. Outcomes were defined by the valve academic research consortium 2 criteria when applicable and compared between the LG and HG groups via Fisher's exact test. Median follow-up was 367 days. Continuous data are shown as median [interquartile range] and categorical data are shown as proportions. Results: The 30-day mortality risk as assessed by Society of Thoracic Surgery score was not significantly different between the LG and HG groups (5.9% [3.5-8.1] vs 6.2% [4.4-7.6], p=0.45). There were no significant differences in outcomes (Table). Conclusion: In a high-volume center, patients undergoing TAVR for severe AS with LG preserved LVEF have no significant difference in adverse outcomes, both in-hospital and on 1-year follow-up, when compared to patients with HG preserved LVEF. (Figure Presented)

BACKGROUND: Appropriate valve sizing is critical in aortic valve replacement. We hypothesized that direct intraoperative valve sizing results in smaller aortic annular diameters compared with sizing based on systolic-phase multidetector computerized tomographic (MDCT) imaging. METHODS AND RESULTS: We retrospectively analyzed 78 patients undergoing surgical aortic valve replacement for severe aortic stenosis between 2012 and 2014 at our institution. Preoperative MDCT measurements of the aortic annulus served as basis for assignment to a theoretical surgical valve size, which was then (1) compared to the implanted valve size and (2) to a theoretical transcatheter aortic valve replacement valve size. To quantify the resulting differences, geometric orifice areas (GOA) were calculated. MDCT-based sizing produced the same valve size for n=34 patients (group CT-same), a larger valve with a 25% increased GOA in n=32 patients (group CT-Lg) and a smaller GOA by 22% in n=12 patients (group CT-Sm). On the basis of MDCT measurements, 41% of valves implanted were undersized. The comparison of intraoperative implanted to a theoretical transcatheter aortic valve replacement valve size resulted in GOAs 25% larger for patients in group CT-same, 40.6% larger in group CT-Lg and 14.6% larger in group CT-Sm. CONCLUSIONS: Preoperative MDCT measurements differ substantially from direct intraoperative assessment of the aortic annulus. Implanted surgical aortic valve replacement valves were smaller relative to MDCT-based sizing in 41% of patients, and the potential GOA was between 25% and 40.6% larger if patients had undergone transcatheter aortic valve replacement.

Background Although transcatheter aortic-valve replacement (TAVR) is an accepted alternative to surgery in patients with severe aortic stenosis who are at high surgical risk, less is known about comparative outcomes among patients with aortic stenosis who are at intermediate surgical risk. Methods We evaluated the clinical outcomes in intermediate-risk patients with severe, symptomatic aortic stenosis in a randomized trial comparing TAVR (performed with the use of a self-expanding prosthesis) with surgical aortic-valve replacement. The primary end point was a composite of death from any cause or disabling stroke at 24 months in patients undergoing attempted aortic-valve replacement. We used Bayesian analytical methods (with a margin of 0.07) to evaluate the noninferiority of TAVR as compared with surgical valve replacement. Results A total of 1746 patients underwent randomization at 87 centers. Of these patients, 1660 underwent an attempted TAVR or surgical procedure. The mean (+/-SD) age of the patients was 79.8+/-6.2 years, and all were at intermediate risk for surgery (Society of Thoracic Surgeons Predicted Risk of Mortality, 4.5+/-1.6%). At 24 months, the estimated incidence of the primary end point was 12.6% in the TAVR group and 14.0% in the surgery group (95% credible interval [Bayesian analysis] for difference, -5.2 to 2.3%; posterior probability of noninferiority, >0.999). Surgery was associated with higher rates of acute kidney injury, atrial fibrillation, and transfusion requirements, whereas TAVR had higher rates of residual aortic regurgitation and need for pacemaker implantation. TAVR resulted in lower mean gradients and larger aortic-valve areas than surgery. Structural valve deterioration at 24 months did not occur in either group. Conclusions TAVR was a noninferior alternative to surgery in patients with severe aortic stenosis at intermediate surgical risk, with a different pattern of adverse events associated with each procedure. (Funded by Medtronic; SURTAVI ClinicalTrials.gov number, NCT01586910 .).

OBJECTIVES: This study sought to evaluate this transcatheter aortic valve (TAV) bioprosthesis in patients who are poorly suitable for surgical aortic valve (AV) replacement. BACKGROUND: A novel self-expandable TAV bioprosthesis was designed to provide a low-profile delivery system, conformable annular sealing, and the ability to resheath and reposition during deployment. METHODS: The Evolut R U.S. study included 241 patients with severe aortic stenosis who were deemed to be at least high risk for surgery treated at 23 clinical sites in the United States. Clinical outcomes at 30 days were evaluated using Valve Academic Research Consortium-2 criteria. An independent echocardiography laboratory was used to evaluate hemodynamic outcomes. RESULTS: Patients were elderly (83.3 +/- 7.2 years of age) and had high surgical risk (Society of Thoracic Surgeons predicted risk of mortality of 7.4 +/- 3.4%). The majority of patients (89.5%) were treated by iliofemoral access. Resheathing or recapturing was performed in 22.6% of patients; more than 1 valve was required in 3 patients (1.3%). The 30-day outcomes included all-cause mortality (2.5%), disabling stroke (3.3%), major vascular complications (7.5%), life-threatening or disabling bleeding (7.1%), and new permanent pacemaker (16.4%). AV hemodynamics were markedly improved at 30 days: the mean AV gradient was reduced from 48.2 +/- 13.0 mm Hg to 7.8 +/- 3.1 mm Hg (p < 0.001) and AV area increased from 0.6 +/- 0.2 cm2 to 1.9 +/- 0.5 cm2 (p < 0.001). Moderate residual paravalvular leak was identified in 5.3% of patients. CONCLUSIONS: We conclude that this novel self-expanding TAV bioprosthesis is safe and effective for the treatment of patients with severe aortic stenosis who are suboptimal for surgery. (Medtronic CoreValve Evolut R U.S. Clinical Study; NCT02207569).