Overview
We did a systematic review and meta-analysis of studies on prevalence and outcomes of arrhythmic mitral annular disjunction. The review is reported according to PRISMA guidelines.
Search strategy, selection criteria, and data extraction
We electronically searched the PUBMED databases with no starting date through June, 2021. The search included MeSH term [‘TAVR’ and ‘pacemaker’] according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, PRISMA. No language restrictions were applied. Additional search strategy included limiting the search applying filters: ‘Clinical Trials’ and published in the last 5 years.
Abstracts and potentially relevant full texts were reviewed independently by two authors (HF and HM) with any conflicts resolved by consensus. Case-control studies, cohort studies, and brief reports were not eligible for inclusion (prespecified by search strategy). Case reports, studies without comparison groups, narrative or systematic literature reviews, preprint papers, and studies reporting on overlapping populations were excluded. The following data were extracted: author’s name, publication date, study design, study population, follow-up period.
A total of fourteen (14) studies were included in the meta-analysis.10-23
Primary outcomes included (rate of new pacemaker implantation in patients undergoing transcatheter aortic valve replacement at 1 year). We intended to evaluate the primary outcome irrespective of valve brand manufacturer, vascular access used, deployment technique/mechanism (auto-expandable vs mechanical). Secondary outcomes included (all-cause mortality at 1-year, 30-day mortality, and cardiovascular mortality). We planned to record any additional patients’ outcomes identified. Where papers described service configuration or resource-use changes without clinical outcomes, we excluded them from the analysis.
Quality appraisal
The quality appraisal was established according to Le Floch and colleagues’ criteria, by two independent assessors (HF and HM).24 This tool appraises the quality of the study based on the following questions: Did this article give an answer to the research question? Did the article focus clearly on the research question? Was the methodology appropriate? Do you believe the results? (Can it be due to chance, bias or confounding?). To be included, the article had to score “yes” on every question.
Statistical analysis
Quantitative meta-analysis was done for an outcome when more than one study presented relevant data. We excluded individual outcomes from studies reporting no adverse outcomes in one or both groups, and studies not satisfying the normality assumption for continuous variables.
A random-effects estimate of the pooled odds of each outcome was generated with use of the Mantel-Haenszel method. Between-study heterogeneity was explored using the I2 statistic, with substantial heterogeneity defined as an I2 value greater than 50%. We reported p values and the amount of accounted heterogeneity for each covariate. Potential publication bias was assessed with Egger’s test and funnel plots for visual inspection when sufficient studies (n>10) were available. Statistical analyses were performed using the Revman software package (Review Manager, Version 5.4. Copenhagen, The Nordic Cochrane Centre, the Cochrane Collaboration).