Meta-analysis of sutureless technology versus standard aortic valve replacement and transcatheter aortic valve replacement

Objective Many published meta-analyses are underpowered. We explored the role of trial sequential analysis (TSA) in assessing the reliability of conclusions in underpowered meta-analyses. Methods We screened The Cochrane Database of Systematic Reviews and selected 100 meta-analyses with a binary outcome, a negative result and sufficient power. We defined a negative result as one where the 95% CI for the effect included 1.00, a positive result as one where the 95% CI did not include 1.00, and sufficient power as the required information size for 80% power, 5% type 1 error, relative risk reduction of 10% or number needed to treat of 100, and control event proportion and heterogeneity taken from the included studies. We re-conducted the meta-analyses, using conventional cumulative techniques, to measure how many false positives would have occurred if these meta-analyses had been updated after each new trial. For each false positive, we performed TSA, using three different approaches. Results We screened 4736 systematic reviews to find 100 meta-analyses that fulfilled our inclusion criteria. Using conventional cumulative meta-analysis, false positives were present in seven of the meta-analyses (7%, 95% CI 3% to 14%), occurring more than once in three. The total number of false positives was 14 and TSA prevented 13 of these (93%, 95% CI 68% to 98%). In a post hoc analysis, we found that Cochrane meta-analyses that are negative are 1.67 times more likely to be updated (95% CI 0.92 to 2.68) than those that are positive. Conclusions We found false positives in 7% (95% CI 3% to 14%) of the included meta-analyses. Owing to limitations of external validity and to the decreased likelihood of updating positive meta-analyses, the true proportion of false positives in meta-analysis is probably higher. TSA prevented 93% of the false positives (95% CI 68% to 98%).

Significant aortic regurgitation (AR) is rare following surgical aortic valve replacement and has been associated with worse outcome. Following transcatheter aortic valve implantation (TAVI), AR is common, but little is known about its determinants and its effect on clinical outcome. To evaluate early outcome and risk factors possibly associated with AR after TAVI. Data were analysed from 690 patients with severe aortic stenosis treated with TAVI enrolled in the prospective multicentre German transcatheter aortic valve interventions registry. The occurrence of AR was evaluated angiographically after device deployment and removal of the catheter and guidewire. Significant AR was defined as AR≥2/4. The study population's mean age was 81.4±6.3 years and men represented 44%. The mean logistic Euroscore was 20.4±13.1%. Overall, 84% of patients received the Medtronic CoreValve system and 16% received the Edwards Sapien valve. Significant AR occurred in 119 patients (17.2%). Factors independently associated with significant AR were aortic valve area (adjusted OR=0.10), annulus measurement by transoesophageal echocardiography (adjusted OR=1.94), male gender (adjusted OR=1.80), cardiogenic shock (adjusted OR=1.94) and renal failure (adjusted OR=0.53). In-hospital death rates were significantly higher in patients with significant AR than in those with no/mild AR (15.1% vs 6.7%, OR=2.50, 95% CI 1.37 to 4.55), as were rates of low cardiac output (20% vs 4.4%) and respiratory failure (16.5% vs 7.1%). Using multivariate analysis, the presence of post-procedural AR≥2/4 remained a strong independent predictor of in-hospital death (adjusted OR=2.43, 95% CI 1.22 to 4.85). Significant AR after TAVI is common and is associated with increased in-hospital mortality. Long-term follow-up is critical to further define the impact of residual AR on clinical outcome. Until these data become available, every effort should be made to prevent and treat this complication.

Minimally invasive surgical procedures (MIS) may offer several advantages over conventional full sternotomy (FS) aortic valve replacement (AVR). A novel class of aortic valve prostheses has been developed for rapid-deployment AVR (RDAVR). We report a randomized, multicenter trial comparing the outcomes for MIS-RDAVR with those of conventional FS-AVR.