Self-Expanding Transcatheter Aortic Valve Replacement in Patients With Low-Gradient Aortic Stenosis

OBJECTIVES

The authors sought to compare clinical and hemodynamic outcomes in patients receiving transcatheter aortic valve replacement (TAVR) for low-gradient (LG) aortic stenosis in the CoreValve EUS (Expanded Use Study) versus those with high-gradient (HG) aortic stenosis from the CoreValve U.S. Pivotal Extreme Risk Trial and CAS (Continued Access Study).

BACKGROUND

The EUS examined the impact of TAVR in patients unsuitable for surgical aortic valve replacement who were excluded from the U.S. Pivotal Extreme Risk Trial due to LG aortic stenosis.

METHODS

EUS patients were stratified by left ventricular ejection fraction: normal (≥50%, LG-normal ejection fraction), and low (<50%, did not respond to dobutamine by generating a mean gradient >40 mm Hg and/or velocity >4.0 m/s, "nonresponders"), and compared with extreme-risk patients from U.S. Pivotal and CAS that had either low resting gradient and responded to dobutamine ("responders"), or a high resting gradient (HG) or velocity. The primary endpoint was all-cause mortality or major stroke at 1 year. Hemodynamics and quality of life are reported at 30 days and 1 year.

RESULTS

At 30 days, patients with LG/low left ventricular ejection fraction (nonresponders and responders) had significantly higher rates of all-cause mortality or major stroke, all-cause mortality, and cardiovascular mortality than both HG and LG-normal ejection fraction patients. At 1 year, only the responders had higher rates of these outcomes in comparison to the other 3 groups. Mean gradient and effective orifice area improved significantly in all patients and were maintained through 1 year. New York Heart Association functional classification and Kansas City Cardiomyopathy Questionnaire overall summary scores improved (p < 0.05) in all cohorts through 1 year. When all 4 subgroups were pooled, both decreasing mean gradient and stroke volume index were associated with increased mortality. Pre-procedural mean gradient was the only hemodynamic independent predictor of 1-year mortality by multivariate analysis.

CONCLUSIONS

In this study, TAVR provided EUS patients significant hemodynamic relief with both 1-year survival and quality of life outcomes comparable to Pivotal and CAS patients (Safety & Efficacy Study of the Medtronic CoreValve System-Treatment of Symptomatic Severe Aortic Stenosis With Significant Comorbidities in Extreme Risk Subjects Who Need Aortic Valve Replacement, NCT01675440; Safety and Efficacy Study of the Medtronic CoreValve System in the Treatment of Symptomatic Severe Aortic Stenosis in High Risk and Very High Risk Subjects Who Need Aortic Valve Replacement, NCT01240902; Safety and Efficacy Continued Access Study of the Medtronic CoreValve System in the Treatment of Symptomatic Severe Aortic Stenosis in Very High Risk Subjects and High Risk Subjects Who Need Aortic Valve Replacement, NCT01531374).

Innovations in Transcatheter Valve Technology: What the Next Five Years Hold

Transcatheter aortic valve replacement is indicated for the treatment of symptomatic severe aortic stenosis in patients at intermediate or greater risk for surgery. Future indications may include low-risk patients, asymptomatic patients, bicuspid valves, moderate aortic stenosis, and pure native aortic valve regurgitation. Key hurdles to overcome include pacemaker risk, vascular injury, paravalvular regurgitation, coronary artery reaccess, durability, and embolic risk. New valve designs include synthetic polymeric valves that may allow for greater durability, in addition to advances in terms of precise positioning and repositioning to reduce the complication rate.

Outcomes in the Randomized CoreValve US Pivotal High Risk Trial in Patients With a Society of Thoracic Surgeons Risk Score of 7% or Less

Importance

Transcatheter aortic valve replacement (TAVR) is now a well-accepted alternative to surgical AVR (SAVR) for patients with symptomatic aortic stenosis at increased operative risk. There is interest in whether TAVR would benefit patients at lower risk.

Objective

The Society of Thoracic Surgeons Predicted Risk of Mortality (STS PROM) has trended downward in US TAVR trials and the STS/American College of Cardiology Transcatheter Valve Therapy Registry. We hypothesized that if the Society of Thoracic Surgeons Predicted Risk of Mortality (STS PROM) alone is sufficient to define decreased risk, the contribution to survival based on the degree of invasiveness of the TAVR procedure will decrease, making it more difficult to show improved survival and benefit over SAVR.

Design, Setting, and Participants

The CoreValve US Pivotal High Risk Trial was a multicenter, randomized, noninferiority trial. This retrospective analysis evaluated patients who underwent an attempted implant and had an STS PROM of 7% or less. The trial was performed at 45 US sites. Patients had severe aortic stenosis and were at increased surgical risk based on their STS PROM score and other risk factors.

Interventions

Eligible patients were randomly assigned (1:1) to self-expanding TAVR or to SAVR.

Main Outcomes and Measures

We retrospectively stratified patients by the overall median STS PROM score (7%) and analyzed clinical outcomes and quality of life using the Kansas City Cardiomyopathy Questionnaire in patients with an STS PROM score of 7% or less.

Results

The mean (SD) ages were 81.5 (7.6) years for the TAVR group and 81.2 years (6.6) for the SAVR group. A little more than half were men (57.9% in the TAVR group and 55.8% in the SAVR group). Of 750 patients who underwent attempted implantation, 383 (202 TAVR and 181 SAVR) had an STS PROM of 7% or less (median [interquartile range]: TAVR, 5.3% [4.3%-6.1%]; SAVR, 5.3% [4.1%-5.9%]). Two-year all-cause mortality for TAVR vs SAVR was 15.0% (95% CI, 8.9-10.0) vs 26.3% (95% CI, 19.7-33.0) (log rank P = .01). The 2-year rate of stroke for TAVR vs SAVR was 11.3% vs 15.1% (log rank P = .50). Quality of life by the Kansas City Cardiomyopathy Questionnaire summary score showed significant and equivalent increases in both groups at 2 years (mean [SD] TAVR, 20.0 [25.0]; SAVR, 18.6 [23.6]; P = .71; both P < .001 compared with baseline). Medical benefit, defined as alive with a Kansas City Cardiomyopathy Questionnaire summary score of at least 60 and a less than 10-point decrease from baseline, was similar between groups at 2 years (TAVR, 51.0%; SAVR, 44.4%; P = .28).

Conclusions and Relevance

Self-expanding TAVR compares favorably with SAVR in high-risk patients with STS PROM scores traditionally considered intermediate risk.

Trial Registration

Clinicaltrials.gov Identifier: NCT01240902.

The State of the Absorb Bioresorbable Scaffold: Consensus From an Expert Panel

Significant progress has been made in the percutaneous coronary intervention technique from the days of balloon angioplasty to modern-day metallic drug-eluting stents (DES). Although metallic stents solve a temporary problem of acute recoil following balloon angioplasty, they leave behind a permanent problem implicated in very late events (in addition to neoatherosclerosis). BRS were developed as a potential solution to this permanent problem, but the promise of these devices has been tempered by clinical trials showing increased risk of safety outcomes, both early and late. This is not too dissimilar to the challenges seen with first-generation DES in which refinement of deployment technique, prolongation of dual antiplatelet therapy, and technical iteration mitigated excess risk of very late stent thrombosis, making DES the treatment of choice for coronary artery disease. This white paper discusses the factors potentially implicated in the excess risks, including the scaffold consideration and deployment technique, and outlines patient and lesion selection, implantation technique, and dual antiplatelet therapy considerations to potentially mitigate this excess risk with the first-generation thick strut Absorb scaffold (Abbott Vascular, Abbott Park, Illinois). It remains to be seen whether these considerations together with technical iterations will ultimately close the gap between scaffolds and metal stents for short-term events while at the same time preserving options for future revascularization once the scaffold bioresorbs.

Durability of quality of life benefits of transcatheter aortic valve replacement: Long-term results from the CoreValve US extreme risk trial

BACKGROUND

For patients with severe aortic stenosis (AS) at extreme surgical risk, transcatheter aortic valve replacement (TAVR) leads to improved survival and health status when compared with medical therapy. Whether the early health status benefits of TAVR in these patients are sustained beyond 1 year of follow-up is unknown.

METHODS AND RESULTS

Six hundred thirty-nine patients with severe AS at extreme surgical risk underwent TAVR in the CoreValve US Extreme Risk Pivotal trial. Health status was evaluated at baseline and at 1, 6, 12, 24, and 36 months using the Kansas City Cardiomyopathy Questionnaire (KCCQ), the Short-Form-12, and the EuroQoL-5D. Analyses were performed using pattern mixture models to account for both death and missing data and were stratified by iliofemoral (IF) and non-iliofemoral (non-IF) access. After TAVR, there was substantial health status improvement in disease-specific and generic scales by 6 to 12 months. Although there were small declines in health status after 12 months, the initial benefits of TAVR were largely sustained through 3 years for both IF and non-IF cohorts (change from baseline in KCCQ Overall Summary score 19.0 points in IF patients and 14.9 points in non-IF patients; P<.01 for both comparisons). Among surviving patients, clinically meaningful (≥10 point) improvements in the KCCQ Overall Summary Score at 3 years were observed in 85.0% and 83.4% of IF and non-IF patients respectively.

CONCLUSIONS

Among extreme risk patients with severe AS, TAVR resulted in large initial health status benefits that were sustained through 3-year follow-up. Although late mortality was high in this population, these findings demonstrate that TAVR offers substantial and durable health status improvements for surviving patients.

Direct Aortic Access for Transcatheter Aortic Valve Replacement Using a Self-Expanding Device

BACKGROUND

Transcatheter aortic valve replacement (TAVR) using a self-expanding valve has been shown to be superior to an open operation in high-risk patients. Extensive iliofemoral peripheral vascular disease can prohibit femoral access. In these cases, direct aortic (DA) implantation may be a suitable option.

METHODS

The current analysis compared outcomes in patients undergoing TAVR with the self-expanding CoreValve prosthesis (Medtronic, Minneapolis, MN) by direct aortic (DA) access vs iliofemoral (IF) access. Patients treated in the CoreValve US High Risk and Extreme Risk Pivotal Trials and Continued Access Study were included. Propensity score matching was used to account for differences in baseline characteristics between groups. Clinical outcomes were compared at 30 days and 1 year.

RESULTS

We identified 394 matched pairs of IF and DA patients. The all-cause mortality rate was significantly higher in the DA group than in the IF group at 30 days (10.9% vs 4.1%, p < 0.001), but this difference was reduced at 1 year (28.1% vs 23.2%, p = 0.063). All-cause mortality or major stroke was significantly higher for DA vs IF access at 30 days (13.5% vs 5.3%, p < 0.001) and at 1 year (30.4% vs 24.2%, p = 0.025). Major/life-threatening bleeding and acute kidney injury were significantly greater in the DA group at 30 days (66.7% vs 35.4% and 19.7% vs 10.0%, respectively, both p < 0.001).

CONCLUSIONS

When femoral access is not feasible, DA access allows effective delivery of the valve but incurs an increased risk of death and adverse events, potentially the result of procedural differences.

Complications After Self-expanding Transcatheter or Surgical Aortic Valve Replacement

Procedural complications following transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) are usually reported as retrospective analyses. We report the first comparison of complications following SAVR or self-expanding TAVR from a prospectively randomized study of high-risk SAVR patients. Three hundred ninety-five TAVR and 402 SAVR patients were prospectively enrolled and randomized 1:1 to TAVR with a CoreValve bioprosthesis or a surgical bioprosthetic valve. The rates of major procedural and vascular complications occurring (periprocedurally (0-3 days) and early (4-30 days)) were compared for TAVR vs SAVR patients. All-cause mortality, stroke, myocardial infarction, and major infection were similar in both periods post procedure. Within 0-3 days, the major vascular complication rate was significantly higher with TAVR (P = 0.003). Life-threatening or disabling bleeding (P < 0.001), encephalopathy (P = 0.02), atrial fibrillation (P < 0.001), and acute kidney injury (P < 0.001) were significantly higher with SAVR. Non-iliofemoral TAVR approaches had a higher incidence of major or life-threatening or disabling bleeding at 0-3days (P < 0.05). Procedural complications unique to TAVR included coronary occlusion 0.5% (2) and TAVR pop outs 2.8% (11) with no valve embolizations. Pop outs were similar between iliofemoral 2.8% (9/324) and non-iliofemoral approaches 3.0% (2/66). Procedural complications unique to SAVR included aortic dissection 0.8% (3/357) and injury to other heart structures 2.0% (7/357). The procedural complication profiles of TAVR and SAVR are unique. Intraoperative deaths were seen in TAVR only. Mortality at 3 and 30 days was similar. The higher incidence of some complications likely reflects the greater invasiveness of SAVR in this aged high-risk population.

Surgical or Transcatheter Aortic-Valve Replacement in Intermediate-Risk Patients

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 .).

Prediction of Poor Outcome After Transcatheter Aortic Valve Replacement

BACKGROUND

A series of models have been developed to identify patients at high risk for poor outcomes after transcatheter aortic valve replacement (TAVR) to help guide treatment choices, offer patients realistic expectations of long-term outcomes, and support decision making.

OBJECTIVES

This study examined the performance of the previously developed TAVR Poor Outcome risk models in an external dataset and explored the incremental contribution of geriatric domains to model performance.

METHODS

Poor outcome after TAVR was defined as death, poor quality of life (QOL), or decline in QOL, as assessed using the Kansas City Cardiomyopathy Questionnaire. We tested 4 TAVR Poor Outcome risk models: 6-month and 1-year full and clinical (reduced) models. We examined each model's discrimination and calibration in the CoreValve trial dataset, and then tested the incremental contribution of frailty and disability markers to the model's discrimination using the incremental discrimination index.

RESULTS

Among 2,830 patients who underwent TAVR in the CoreValve US Pivotal Extreme and High Risk trials and associated continued access registries, 31.2% experienced a poor outcome at 6 months following TAVR (death, 17.6%; very poor QOL, 11.6%; QOL decline, 2.0%) and 50.8% experienced a poor outcome at 1 year (death, 30.2%; poor QOL, 19.6%; QOL, decline 1.0%). The models demonstrated similar discrimination as in the Placement of Aortic Transcatheter Valves Trial cohorts (c-indexes, 0.637 to 0.665) and excellent calibration. Adding frailty as a syndrome increased the c-indexes by 0.000 to 0.004 (incremental discrimination index, p < 0.01 for all except the 1-year clinical model), with the most important individual components being disability and unintentional weight loss.

CONCLUSIONS

Although discrimination of the TAVR Poor Outcome risk models was generally moderate, calibration was excellent among patients with different risk profiles and treated with a different TAVR device. These findings demonstrated the value of these models for individualizing outcome predictions in high-risk patients undergoing TAVR.

Transcatheter Aortic Valve Replacement Versus Surgery in Women at High Risk for Surgical Aortic Valve Replacement (from the CoreValve US High Risk Pivotal Trial)

The objective of this study was to compare outcomes in women after surgical aortic valve replacement (SAVR) versus transcatheter aortic valve replacement (TAVR) using a self-expanding prosthesis in patients with severe aortic stenosis who were at high risk for SAVR. Although registries and meta-analyses have suggested that TAVR is of considerable benefit in women, perhaps even more so than in men, a rigorous evaluation of TAVR with a self-expanding valve versus SAVR in women from a randomized trial has not been performed. Patients with severe aortic stenosis were randomized 1:1 to either TAVR or SAVR. Outcomes at 1 year are reported. Treatment was attempted in a total of 353 women (183 TAVR and 170 SAVR). Baseline characteristics and predicted risk of the 2 groups were comparable, although the frequency of diabetes mellitus was lower in patients undergoing TAVR (33.3% vs 45.3%; p = 0.02). TAVR-treated patients experienced a statistically significant 1-year survival advantage compared with SAVR patients (12.7% vs 21.8%; p = 0.03). The composite all-cause mortality or major stroke rate also favored TAVR (14.9% vs 24.2%; p = 0.04). Quality of life, as measured by the Kansas City Cardiomyopathy Questionnaire summary score, for both the TAVR and SAVR groups increased significantly from baseline to 1 year. In conclusion, female TAVR patients had lower 1-year mortality and lower 1-year all-cause mortality or major stroke compared with women undergoing SAVR, with both cohorts experiencing improved quality of life. Further studies specifically in women are warranted to validate these findings.

Transcatheter Aortic Valve Replacement in Women Versus Men (from the US CoreValve Trials)

Treatment for severe symptomatic aortic stenosis has changed significantly in recent years due to advances in transcatheter aortic valve replacement (TAVR). Recent studies with the CoreValve prosthesis have demonstrated superior results compared with surgical aortic valve replacement in patients at increased risk for surgery, but there are limited data on gender-related differences in patient characteristics and outcomes with this device. We compared baseline characteristics and clinical outcomes in women and men undergoing TAVR with the CoreValve prosthesis. A total of 3,687 patients (1,708 women and 1,979 men) were included. At baseline, women tended to be slightly older and to have increased frailty, but they had fewer cardiac co-morbidities, higher left ventricular systolic function, less coronary artery disease, and fewer previous strokes. All-cause mortality was 5.9% for women and 5.8% for men at 30 days (p = 0.87) and 24.1% and 21.3%, respectively, at 1 year (p = 0.08). The incidence of stroke was 5.7% in women and 4.0% in men at 30 days (p = 0.02) and 9.3% and 7.7%, respectively, at 1 year (p = 0.05). Women had a higher incidence of bleeding, including more life-threatening bleeds, and a greater incidence of major vascular complications than men at 30 days. Device success was achieved in 86.9% of women and 86.1% of men (p = 0.50). In conclusion, although there were significant baseline differences and procedure-related complications between women and men undergoing TAVR with the CoreValve prosthesis, this analysis found no significant difference in 30-day or 1-year mortality.

Relationship of Annular Sizing Using Multidetector Computed Tomographic Imaging and Clinical Outcomes After Self-Expanding CoreValve Transcatheter Aortic Valve Replacement

Background—

Multidetector computed tomography is useful for determining the appropriate transcatheter heart valve (THV) size in patients with severe aortic stenosis who are suboptimal surgical candidates. The relationship between adherence to the recommended CoreValve sizing algorithm and clinical outcomes is not known.

Methods and Results—

We evaluated 1023 patients with severe aortic stenosis deemed high or extreme risk for surgery treated with the CoreValve THV. All patients underwent preprocedural multidetector computed tomography, and the scans were reviewed at a central analysis center using standardized software. Compliance to a recommended sizing algorithm was used to identify patients with below-range, in-range, and above-range THV sizing. A device annular sizing ratio (DAR) was also calculated based on the native annulus perimeter and perimeter of the selected THV. Clinical end points included the presence of paravalvular aortic regurgitation evaluated by an independent echocardiographic laboratory. Adherence to the sizing algorithm was highest with a 31-mm THV (92.6%) and lowest with the 23-mm THV (38.5%). Below-range sizing was associated with a higher rate of moderate or severe paravalvular aortic regurgitation (15.3%) than in-range (6.5%) or above-range (10.0%; P <0.001) sizing. Higher DARs were associated with lower rates of moderate or severe paravalvular aortic regurgitation: DAR ≤10%, 17.6%; DAR 10% to 15%, 9.9%; DAR 15% to 20%, 6.3%; and DAR >20%, 4.9%; P <0.001. There was no increase in clinical events associated with higher DARs.

Conclusions—

Adherence to a sizing algorithm guided by multidetector computed tomography resulted in lower rates of paravalvular aortic regurgitation after self-expanding transcatheter valve replacement without an increase in complications.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01240902.

2-Year Outcomes After Iliofemoral Self-Expanding Transcatheter Aortic Valve Replacement in Patients With Severe Aortic Stenosis Deemed Extreme Risk for Surgery

BACKGROUND

We reported favorable 1-year outcomes in patients unsuitable for surgery who underwent self-expanding transcatheter aortic valve replacement (TAVR) compared with an objective performance goal. Longer-term outcomes in these patients are not known.

OBJECTIVES

This study sought to evaluate the 2-year safety and efficacy in patients with severe aortic stenosis (AS) at extreme risk of surgery treated with self-expanding TAVR.

METHODS

We performed a prospective, multicenter, controlled, nonrandomized investigation of self-expanding TAVR in patients with severe AS and prohibitive surgical risk. We report the 2-year clinical outcomes in these patients.

RESULTS

A total of 489 extreme-risk patients were treated transfemorally with a self-expanding aortic bioprosthesis at 41 centers. The rate of all-cause mortality or major stroke was 38.0% at 2 years (all-cause mortality, 36.5%; major stroke, 5.1%). The rates of all-cause mortality, cardiovascular mortality, and major stroke were 36.6%, 26.2%, and 5.1%, respectively, at 2 years. Between 1 and 2 years, the incremental all-cause mortality, cardiovascular mortality, and major stroke rates were 12.3%, 7.9%, and 0.8%, respectively. Multivariable predictors of all-cause mortality at 2 years included the presence of coronary artery disease and admission from an assisted living center. A Society of Thoracic Surgeons score >15% was also predictive of 2-year all-cause mortality. At 2 years, 94% of patients had New York Heart Association functional class I or II symptoms. The frequency of moderate or severe paravalvular regurgitation (4.3% at 1 year; 4.4% at 2 years) was unchanged between the first and second year.

CONCLUSIONS

Patients with severe AS at extreme surgical risk treated with self-expanding TAVR continued to show good clinical outcomes and hemodynamic valve performance at 2 years. The presence of comorbid conditions rather than valve performance affected 2-year outcomes in these patients. (Safety and Efficacy Study of the Medtronic CoreValve System in the Treatment of Symptomatic Severe Aortic Stenosis in High Risk and Very High Risk Subjects Who Need Aortic Valve Replacement; NCT01240902).

2-Year Outcomes in Patients Undergoing Surgical or Self-Expanding Transcatheter Aortic Valve Replacement

BACKGROUND

The U.S. pivotal trial for the self-expanding valve found that among patients with severe aortic stenosis at increased risk for surgery, the 1-year survival rate was 4.9 percentage points higher in patients treated with a self-expanding transcatheter aortic valve bioprosthesis than in those treated with a surgical bioprosthesis.

OBJECTIVES

Longer-term clinical outcomes were examined to confirm if this mortality benefit is sustained.

METHODS

Patients with severe aortic stenosis who were at increased surgical risk were recruited. Eligible patients were randomly assigned in a 1:1 ratio to transcatheter aortic valve replacement with the self-expanding transcatheter valve (transcatheter aortic valve replacement [TAVR] group) or to aortic valve replacement with a surgical bioprosthesis (surgical group). The 2-year clinical and echocardiographic outcomes were evaluated in these patients.

RESULTS

A total of 797 patients underwent randomization at 45 centers in the United States. The rate of 2-year all-cause mortality was significantly lower in the TAVR group (22.2%) than in the surgical group (28.6%; log-rank test p < 0.05) in the as-treated cohort, with an absolute reduction in risk of 6.5 percentage points. Similar results were found in the intention-to-treat cohort (log-rank test p < 0.05). The rate of 2-year death or major stroke was significantly lower in the TAVR group (24.2%) than in the surgical group (32.5%; log-rank test p = 0.01).

CONCLUSIONS

In patients with severe aortic stenosis who are at increased surgical risk, the higher rate of survival with a self-expanding TAVR compared with surgery was sustained at 2 years. (Safety and Efficacy Study of the Medtronic CoreValve System in the Treatment of Symptomatic Severe Aortic Stenosis in High Risk and Very High Risk Subjects Who Need Aortic Valve Replacement; NCT01240902).

Early safety and efficacy of percutaneous left atrial appendage suture ligation: results from the U.S. transcatheter LAA ligation consortium

BACKGROUND

Transcatheter left atrial appendage (LAA) ligation may represent an alternative to oral anticoagulation for stroke prevention in atrial fibrillation.

OBJECTIVES

This study sought to assess the early safety and efficacy of transcatheter ligation of the LAA for stroke prevention in atrial fibrillation.

METHODS

This was a retrospective, multicenter study of consecutive patients undergoing LAA ligation with the Lariat device at 8 U.S. sites. The primary endpoint was procedural success, defined as device success (suture deployment and <5 mm leak by post-procedure transesophageal echocardiography), and no major complication at discharge (death, myocardial infarction, stroke, Bleeding Academic Research Consortium bleeding type 3 or greater, or cardiac surgery). Post-discharge management was per operator discretion.

RESULTS

A total of 154 patients were enrolled. Median CHADS2 score (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke, transient ischemic attack, or thromboembolism [doubled]) was 3 (interquartile range: 2 to 4). Device success was 94%, and procedural success was 86%. A major complication occurred in 15 patients (9.7%). There were 14 major bleeds (9.1%), driven by the need for transfusion (4.5%). Significant pericardial effusion occurred in 16 patients (10.4%). Follow-up was available in 134 patients at a median of 112 days (interquartile range: 50 to 270 days): Death, myocardial infarction, or stroke occurred in 4 patients (2.9%). Among 63 patients with acute closure and transesophageal echocardiography follow-up, there were 3 thrombi (4.8%) and 13 (20%) with residual leak.

CONCLUSIONS

In this initial multicenter experience of LAA ligation with the Lariat device, the rate of acute closure was high, but procedural success was limited by bleeding. A prospective randomized trial is required to adequately define clinical efficacy, optimal post-procedure medical therapy, and the effect of operator experience on procedural safety.

Transcatheter aortic-valve replacement with a self-expanding prosthesis

BACKGROUND

We compared transcatheter aortic-valve replacement (TAVR), using a self-expanding transcatheter aortic-valve bioprosthesis, with surgical aortic-valve replacement in patients with severe aortic stenosis and an increased risk of death during surgery.

METHODS

We recruited patients with severe aortic stenosis who were at increased surgical risk as determined by the heart team at each study center. Risk assessment included the Society of Thoracic Surgeons Predictor Risk of Mortality estimate and consideration of other key risk factors. Eligible patients were randomly assigned in a 1:1 ratio to TAVR with the self-expanding transcatheter valve (TAVR group) or to surgical aortic-valve replacement (surgical group). The primary end point was the rate of death from any cause at 1 year, evaluated with the use of both noninferiority and superiority testing.

RESULTS

A total of 795 patients underwent randomization at 45 centers in the United States. In the as-treated analysis, the rate of death from any cause at 1 year was significantly lower in the TAVR group than in the surgical group (14.2% vs. 19.1%), with an absolute reduction in risk of 4.9 percentage points (upper boundary of the 95% confidence interval, -0.4; P<0.001 for noninferiority; P = 0.04 for superiority). The results were similar in the intention-to-treat analysis. In a hierarchical testing procedure, TAVR was noninferior with respect to echocardiographic indexes of valve stenosis, functional status, and quality of life. Exploratory analyses suggested a reduction in the rate of major adverse cardiovascular and cerebrovascular events and no increase in the risk of stroke.

CONCLUSIONS

In patients with severe aortic stenosis who are at increased surgical risk, TAVR with a self-expanding transcatheter aortic-valve bioprosthesis was associated with a significantly higher rate of survival at 1 year than surgical aortic-valve replacement. (Funded by Medtronic; U.S. CoreValve High Risk Study ClinicalTrials.gov number, NCT01240902.).

Percutaneous left atrial appendage suture ligation using the LARIAT device in patients with atrial fibrillation: initial clinical experience

OBJECTIVES

The purpose of the study was to determine the efficacy and safety of left atrial appendage (LAA) closure via a percutaneous LAA ligation approach.

BACKGROUND

Embolic stroke is the most devastating consequence of atrial fibrillation. Exclusion of the LAA is believed to decrease the risk of embolic stroke.

METHODS

Eighty-nine patients with atrial fibrillation were enrolled to undergo percutaneous ligation of the LAA with the LARIAT device. The catheter-based LARIAT device consists of a snare with a pre-tied suture that is guided epicardially over the LAA. LAA closure was confirmed with transesophageal echocardiography (TEE) and contrast fluoroscopy immediately, then with TEE at 1 day, 30 days, 90 days, and 1 year post-LAA ligation.

RESULTS

Eighty-five (96%) of 89 patients underwent successful LAA ligation. Eighty-one of 85 patients had complete closure immediately. Three of 85 patients had a ≤ 2-mm residual LAA leak by TEE color Doppler evaluation. One of 85 patients had a ≤ 3-mm jet by TEE. There were no complications due to the device. There were 3 access-related complications (during pericardial access, n = 2; and transseptal catheterization, n = 1). Adverse events included severe pericarditis post-operatively (n = 2), late pericardial effusion (n = 1), unexplained sudden death (n = 2), and late strokes thought to be non-embolic (n = 2). At 1 month (81 of 85) and 3 months (77 of 81) post-ligation, 95% of the patients had complete LAA closure by TEE. Of the patients undergoing 1-year TEE (n = 65), there was 98% complete LAA closure, including the patients with previous leaks.

CONCLUSIONS

LAA closure with the LARIAT device can be performed effectively with acceptably low access complications and periprocedural adverse events in this observational study.

Catheter-Based Left Atrial Appendage (LAA) Ligation for the Prevention of Embolic Events Arising From the LAA

Background—

Surgical ligation of the left atrial appendage (LAA) has been shown to be an effective alternative to warfarin therapy in patients with atrial fibrillation. A novel catheter-based approach for LAA ligation was evaluated for safety and effectiveness in a canine model.

Methods and Results—

A total of 26 healthy mongrel dogs underwent ligation of the LAA through a catheter-based approach. Intracardiac echocardiography and contrast fluoroscopy were used to position a marker balloon at the origin of the LAA. An over-the-wire approach was used to guide the LARIAT snare device over the LAA to enable ligation of the LAA. Sixteen dogs were euthanized acutely. The LAA was examined to assess the placement and completeness of the ligation. The remaining 10 dogs were used for long-term follow-up. The snare delivery device was able to completely capture, advance, and close the anatomic base of the LAA in all cases. In all animals, complete LAA exclusion through this closed-chest approach was achieved without complications. Chronic follow-up revealed healthy active dogs. Examination of the LAA at 7 days, 1 month, and 3 months demonstrated completely endothelialized orifice of the LAA.

Conclusions—

Using a closed-chest approach in the canine model, the catheter-based snare delivery device achieved safe and reliable ligation of the entire LAA. The clinical application of this novel approach may provide an alternative to warfarin or to permanent device implants in patients with nonvalvular atrial fibrillation for the prevention of embolic events originating from the LAA.

Mortality at 1 year for the direct comparison of tirofiban and abciximab during percutaneous coronary revascularization: do tirofiban and ReoPro give similar efficacy outcomes at trial 1-year follow-up

AIMS

Compared with placebo, abciximab has been associated with mortality reduction at late follow-up. The TARGET trial was performed to test whether tirofiban and abciximab provide similar efficacy outcomes among patients undergoing non-emergent, stent-based percutaneous coronary intervention. We report here the 1-year mortality of the study population.

METHODS AND RESULTS

In 18 countries at 149 hospitals, 4,809 patients undergoing elective or urgent stent implantation were randomly assigned a bolus and infusion of tirofiban or abciximab. Ischaemic events were assessed at 30 days and 6 months and mortality was assessed at 1 year. We previously reported that abciximab was superior to tirofiban considering the composite rate of death or myocardial infarction at 30 days among all patients and at 6 months among those with an acute coronary syndrome (ACS). At 1-year follow-up death occurred in 46 (1.9%) patients who received tirofiban and 42 (1.7%) patients who received abciximab (hazard ratio 1.10, 95% CI 0.72-1.67; P=0.660). Mortality rates for patients with ACS were 2.3% with tirofiban vs. 2.2% with abciximab (hazard ratio 1.03, 95% CI 0.64-1.67; P=0.897) and those without ACS were 1.4 vs. 1.0% (hazard ratio 1.32, 95% CI 0.56-3.13; P=0.530).

CONCLUSION

At 1 year, tirofiban provided a similar level of survival benefit compared with abciximab.

Outcomes at 6 months for the direct comparison of tirofiban and abciximab during percutaneous coronary revascularisation with stent placement: the TARGET follow-up study

BACKGROUND

Two placebo-controlled trials testing intravenous platelet glycoprotein IIb/IIIa antagonists in the setting of percutaneous coronary revascularisation with intracoronary stents have shown a durable reduction in ischaemic events to 6 months. These trials differed regarding their patient population, IIb/IIIa inhibitor, and reported extent of benefit. Whether a small-molecule agent affecting only the IIb/IIIa receptor would provide a similar outcome for ischaemic events and clinical restenosis at 6 months when directly compared with a monoclonal antibody known to affect several integrin receptors is unknown.

METHODS

In 18 countries at 149 hospitals, 4809 patients undergoing elective or urgent stent implantation were randomly assigned a bolus and infusion of tirofiban or abciximab. Patients were followed for 6 months for the occurrence of death, myocardial infarction, and any target-vessel revascularisation. The results at 30 days have been reported previously.

FINDINGS

At 6 months the composite endpoint of death, myocardial infarction, and target-vessel revascularisation occurred in 356 (14.8%) patients who received tirofiban and 345 (14.3%) patients who received abciximab (hazard ratio 1.04, 95% CI 0.90-1.21; p=0.591). The rates for the individual endpoints were 191 (8.0%) versus 159 (6.6%) for myocardial infarction (hazard ratio 1.21, 95% CI 0.98-1.50; p=0.074), 26 (1.1%) versus 25 (1.0%) for death (1.04, 0.60-1.80; p=0.893), and 194 (8.1%) versus 208 (8.6%) for target-vessel revascularisation (0.93, 0.77-1.14; p=0.495).

INTERPRETATION

At 6 months, tirofiban provided a similar level of overall protection to abciximab against the composite of death, myocardial infarction, and any target-vessel revascularisation.

Effects of integrelin, a platelet glycoprotein IIb/IIIa receptor antagonist, in unstable angina. A randomized multicenter trial

BACKGROUND

Although aspirin is beneficial in patients with unstable angina, it is a relatively weak inhibitor of platelet aggregation. The effect of Integrelin, which inhibits the platelet fibrinogen receptor glycoprotein (GP) IIb/IIIa, on the frequency and duration of Holter ischemia was evaluated in 227 patients with unstable angina.

METHODS AND RESULTS

Patients received intravenous heparin and standard ischemic therapy and were randomized to receive oral aspirin and placebo Integrelin; placebo aspirin and low-dose Integrelin. 45 micrograms/kg bolus followed by a 0.5 microgram.kg-1. min-1 continuous infusion; or placebo aspirin and high-dose Integrelin, 90 micrograms/kg bolus followed by a 1.0-microgram.kg-1, min-1 constant infusion. Study drug was continued for 24 to 72 hours, and Holter monitoring was performed. Patients randomized to high-dose Integrelin experienced 0.24 +/- 0.11 ischemic episodes (mean +/- SEM) on Holter lasting 8.41 +/- 5.29 minutes over 24 hours of study drug infusion. Patients randomized to aspirin experienced a greater number (1.0 +/- 0.33, P < .05) and longer duration (26.2 +/- 9.8 minutes, P = .01) of ischemic episodes than the high-dose Integrelin group. There was no evidence of rebound ischemia after withdrawal of study drug. In 46 patients, platelet aggregation was rapidly inhibited by Integrelin in a dose-dependent fashion. The number of clinical events was small, and there were no bleeding differences in the three treatment arms.

CONCLUSIONS

Intravenous Integrelin is well tolerated, is a potent reversible inhibitor of platelet aggregation, and added to full-dose heparin reduces the number and duration of Holter ischemic events in patients with unstable angina compared with aspirin.

An analysis of the safety of performing dobutamine stress echocardiography in an ambulatory setting

Dobutamine echocardiography has become widely used in the past decade in the evaluation of patients with suspected coronary artery disease who are unable to undergo exercise treadmill or bicycle testing. The safety of this procedure has been studied in a hospital-based setting. However, no studies thus far have evaluated the safety of this procedure in an office-based setting, remote from a hospital. We performed dobutamine echocardiography on 127 patients in an office-based setting, remote from a hospital. Throughout the course of this study there were no deaths, myocardial infarctions, sustained episodes of ventricular tachycardia, or syncopal episodes associated with dobutamine infusion. The frequency of noncardiac side effects was 29%, the majority of which were nausea, vomiting, and paresthesias. Three patients had nonsustained ventricular tachycardia, none of whom had symptoms. We conclude that dobutamine echocardiography is safe, well tolerated, and useful in an office-based setting.

Adjunctive thrombolytic agents with coronary interventional techniques

Thrombolytics are used in a variety of interventional procedures, including direct lytic therapy, and in conjunction with PTCA, directional atherectomy and intracoronary stenting. The dosage and variety of thrombolytics is controversial. This article examines all potential uses of thrombolytics and reports on major trials using thrombolytics in these situations.

Bilateral renal artery occlusion: an unusual presentation of atrial fibrillation and hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy predisposes patients to atrial fibrillation and the development of systemic embolization. We describe a rare case of bilateral renal artery thrombosis which presented as acute renal failure requiring dialysis. The patient was successfully treated with a selective, continuous infusion of urokinase which resulted in the return of adequate renal function.

Successful prolonged local infusion of urokinase for the hypothenar hammer syndrome

Ulnar artery thrombosis secondary to trauma, also known as the hypothenar hammer syndrome, has been most commonly been treated by surgical techniques. Applying concepts of local lysis of thrombotic occlusion used in cardiac and peripheral vascular intervention, we describe a method of correction of the hypothenar hammer syndrome by prolonged urokinase infusion.