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

Coronary flow abnormalities in chronic kidney disease: A systematic review and meta-analysis

BACKGROUND: Coronary vasomotion abnormalities have been described in small studies but not studied systematically. We aimed to review the present literature and analyze it to improve our understanding of chronic kidney disease (CKD) related-coronary microvascular dysfunction. OBJECTIVE: Coronary flow reserve (CFR) is a well-known measure of coronary vasomotion. We aimed to assess the difference in CFR among participants with and without CKD. METHODS: PubMed, Embase, and Cochrane CENTRAL were systematically reviewed to identify studies that compared CFR in participants with and without CKD. We estimated standardized mean differences in mean CFR reported in these studies. We performed subgroup analyses according to imaging modality, and the presence of significant epicardial coronary artery disease. RESULTS: In 14 observational studies with 5966 and 1410 patients with and without CKD, the mean estimated glomerular filtration rate (eGFR) was 29 ± 04 and 87 ± 25 ml/min/1.73 m2 , respectively. Mean CFR was consistently lower in patients with CKD in all studies and the cumulative mean difference was statistically significant (2.1 ± .3 vs. 2.7 ± .5, standardized mean difference -.8, 95% CI -1.1, -.6, p \u3c .05). The lower mean CFR was driven by both significantly higher mean resting flow velocity (.58 cm/s, 95% CI .17, .98) and lower mean stress flow velocity (-.94 cm/s, 95% CI -1.75, -.13) in studies with CKD. This difference remained significant across diagnostic modalities and even in absence of epicardial coronary artery disease. In meta-regression, there was a significant positive relationship between mean eGFR and mean CFR (p \u3c .05). CONCLUSION: Patients with CKD have a significantly lower CFR versus those without CKD, even in absence of epicardial coronary artery disease. There is a linear association between eGFR and CFR. Future studies are required to understand the mechanisms and therapeutic implications of these findings. KEY POINTS: In this meta-analysis of observational studies, there was a significant reduction in coronary flow reserve in studies with chronic kidney disease versus those without. This difference was seen even in absence of epicardial coronary artery disease. In meta-regression, a lower estimate glomerular filtration rate was a significant predictor of lower coronary flow reserve. Coronary microvascular dysfunction, rather than atherosclerosis-related epicardial disease may underly increase cardiovascular risk in a patient with chronic kidney disease

Relationship of Beam Angulation and Radiation Exposure in the Cardiac Catheterization Laboratory

ObjectivesThe aim of this study was to analyze the relationship between beam angulation and air kerma in a modern cardiac catheterization laboratory.BackgroundRecent 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.MethodsProspectively 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.ResultsMedian 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.ConclusionsThis 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