Comparison of multicenter registries and randomized control trials for transcatheter aortic valve replacement (TAVR).

BACKGROUND: TAVR has emerged as an attractive alternative for treatment of severe aortic stenosis in high risk surgical patients. Despite several large multicenter registries, only one randomized trial (PARTNER) has been published. OBJECTIVE: We aimed to compare the outcomes obtained using multicenter registries and the PARTNER trial. METHODS: Standard MEDLINE search strategy was used to find multicenter registries, reporting clinical outcomes following TAVR. Meta-analytic techniques were utilized to calculate pooled outcomes across multicenter registries and compare them to outcomes in PARTNER trial. RESULTS: Pooled 30-day mortality rate from the registries was 9.2%, which was significantly higher than that in the PARTNER trial (3.8%). Medium-term mortality rates were similar between the PARTNER trial and the multicenter registries. Pooled 30-day and 1-year stroke rates in multicenter registries were 2.6% and 3.8%, respectively. On the other hand, the corresponding rates in PARTNER trial were 5.2% and 7.6%, respectively. In the registry-related cohorts, pooled 30-day and 1-year mortality rates were 6.8% and 20.8% in the transfemoral group and 12.2% and 32.2% in the transapical group. In the PARTNER trial, the pooled incidence of 30-day and 1-year mortality rates were 3.9% and 26.2% in the transfemoral group and 3.8% and 29.0% in the transapical group. CONCLUSIONS: Short-term results in PARTNER were better than those reported in the registries, which may be due to better patient selection and aggressive bailout techniques. Similarity of medium-term outcomes between registries and PARTNER highlights that patient selection for TAVR is critical due to considerable risk of mortality in the first year even after the successful procedure.

Relationship of beam angulation and radiation exposure in the cardiac catheterization laboratory.

OBJECTIVES: The aim of this study was to analyze the relationship between beam angulation and air kerma in a modern cardiac catheterization laboratory. BACKGROUND: Recent reports have identified the merits of reducing radiation scatter, an important determinant of radiation dose in the catheterization laboratory. Radiation scatter is poorly characterized in the context of catheterization laboratories using modern digital equipment. Understanding the principles of dosimetry may reduce the radiation exposure to patients, providers, and medical staff. METHODS: Prospectively captured radiation data were extracted from a database of 1,975 diagnostic catheterizations (DCs) and 755 percutaneous coronary interventions (PCIs), which included 138,342 fluoroscopic and 35,440 acquisition (cine) sequences. Fluoroscopy and acquisition modes were categorized into tertiles based on the total air kerma measured at a standard reference point. Radiation maps were modeled according to the relative proportion of exposure in each projection. RESULTS: Median air kerma during DCs and PCIs was 677 and 2,188 mGy, respectively. Fluoroscopy contributed to 66.3% of total dose during PCIs compared with 39.7% during DCs (p < 0.001). Fluoroscopy was more sensitive to changes in angulation with a rapid increase in total air kerma on small increases in beam angulation. Complex spatial maps were created to study the impact of angulation and other covariates on total air kerma. Besides beam angulation, body surface area was the strongest predictor of the total air kerma. CONCLUSIONS: This study uniquely describes radiation dosimetry using contemporary equipment in a real-world setting. Extreme angulations were associated with high air kerma values. Fluoroscopy compared with acquisition was more sensitive to changes in angulation, with relatively larger increases in total air kerma with small increases in steepness of the angulation.

Percutaneous left atrial appendage occlusion for stroke prophylaxis in nonvalvular atrial fibrillation: a systematic review and analysis of observational studies.

OBJECTIVES: The goal of this study was to provide a systematic review and analysis of observational studies on percutaneous left atrial appendage (LAA) occlusion for stroke prophylaxis in nonvalvular atrial fibrillation (NVAF). BACKGROUND: A recent randomized controlled trial in patients with NVAF suggested noninferiority of percutaneous LAA occlusion versus medical management for stroke prevention. However, the use of percutaneous devices remains controversial because of limited literature on their efficacy and safety. We performed a systematic analytical review of existing observational studies to assess the rate of neurological events for patients treated with occlusion devices. METHODS: A comprehensive search of the Medline, Scopus, and Web of Science databases from inception through August 1, 2013, was conducted using pre-defined criteria. We included studies reporting implantation in at least 10 patients and a follow-up of 6 months or more. RESULTS: In 17 eligible studies, a total of 1,052 devices were implanted in 1,107 patients with 1,586.4 person-years (PY) of follow-up. The adjusted incidence rate of stroke was 0.7/100 PY (95% confidence interval [CI]: 0.3 to 1.1/100 PY), of transient ischemic attacks was 0.5/100 PY (95% CI: 0.1 to 1.8/100 PY), and of combined neurological events (strokes or transient ischemic attacks) was 1.1/100 PY (95% CI: 0.6 to 1.6/100 PY). Access site vascular complications and pericardial effusion were the most commonly observed procedural complications at a rate of 8.6% (95% CI: 6.3% to 11.7%) and 4.3% (95% CI: 3.1% to 5.9%), respectively. CONCLUSIONS: Our systematic review suggested comparable efficacy of LAA occlusion devices compared with historical controls treated with adjusted-dose warfarin and other anticoagulation strategies for prevention of stroke in patients with NVAF.

Impact of diabetes on long-term mortality following multivessel percutaneous interventions: an insight into optimal statistical analysis.

BACKGROUND: Several studies have demonstrated better long-term outcomes with drug eluting stents (DES) as compared to bare metal stents (BMS) among diabetics with coronary artery disease (CAD). A significant heterogeneity exists with respect to the optimal statistical strategy to analyze stent related data. METHODS: We used our percutaneous intervention (PCI) registry to identify all diabetics with CAD, who underwent PCI on two or more vessel territories between 2003 and 2009. Long-term mortality was assessed using the social security death index. Six different analytical strategies were applied. RESULTS: A total of 1568 DES and 336 BMS interventions were encountered in 756 diabetics. Considerable differences were observed in the results between the methods applied. Generalized estimating equation (GEE) approach with an autoregressive correlation structure (GEE) was a robust method to account for the cluster structure, since the measurements taken through time on the same person were assumed to be highly correlated, if they were spaced more closely in time. Diabetics undergoing PCI with BMS had a significantly higher long-term mortality as compared to the patients undergoing DES-PCI [Hazard ratio (95% CI): 1.47 (1.04-2.09)]. CONCLUSION: There is a great potential for erroneous interpretation of PCI data due to complex spatial and temporal clustering. Use of GEE with autoregressive correlation matrix and robust variance is most optimal to account for the clustered nature of the PCI related data. Using GEE, we observed that there is a 47% (4%-119%) higher hazard for mortality among diabetics undergoing BMS-PCI as compared to diabetics undergoing DES-PCI.

Meta-analysis of transcatheter closure versus medical therapy for patent foramen ovale in prevention of recurrent neurological events after presumed paradoxical embolism.

OBJECTIVES: In this study, a meta-analysis of observational studies was performed to compare the rate of recurrent neurological events (RNE) between transcatheter closure and medical management of patients with cryptogenic stroke/transient ischemic attack (TIA) and concomitant patent foramen ovale (PFO). BACKGROUND: A significant controversy surrounds the optimal strategy for treatment of cryptogenic stroke/TIA and coexistent PFO. METHODS: We conducted a MEDLINE search with standard search terms to determine eligible studies. RESULTS: Adjusted incidence rates of RNE were 0.8 (95% confidence interval [CI]: 0.5 to 1.1) events and 5.0 (95% CI: 3.6 to 6.9) events/100 person-years (PY) in the transcatheter closure and medical management arms, respectively. Meta-analysis of the limited number of comparative studies and meta-regression analysis suggested that the transcatheter closure might be superior to the medical therapy in prevention of RNE after cryptogenic stroke. Comparison of the anticoagulation and antiplatelet therapy subgroups of the medical arm yielded a significantly lower risk of RNE within patients treated with anticoagulants. Device-related complications were encountered at the rate of 4.1 (95% CI: 3.2 to 5.0) events/100 PY, with atrial arrhythmias being the most frequent complication. After transcatheter closure, RNE did not seem to be related to the pre-treatment shunt size or the presence of residual shunting in the follow-up period. Significant benefit of transcatheter PFO closure was apparent in elderly patients, patients with concomitant atrial septal aneurysm, and patients with thrombophilia. CONCLUSIONS: Rates of RNE with transcatheter closure and medical therapy in patients presenting with cryptogenic stroke or TIA were estimated at 0.8 and 5.0 events/100 PY. Further randomized controlled trials are needed to conclusively compare these 2 management strategies.