Literature search and data sources
This systematic review and meta-analysis were executed using a
preplanned protocol. The results were reported according to the
Preferred Reporting Items for Systematic Reviews and Meta‐Analyses
(PRISMA) guidelines(5). An electronic search with the assistance of a
librarian was conducted. We searched the databases including Ovid
MEDLINE, Ovid Embase Scopus, Web of Science, Google Scholar, and EBSCO
CINAHL from inception up to December 26th, 2020 were queried. The search
was not restricted to time, publication status or language. Moreover,
the references as well as studies related to first author and
corresponding author of included studies were hand-searched for other
relevant studies. We used Medical Subject Headings (MeSH) terms with
keywords sleep apnea, sleep-disordered breathing, hypoventilation
disorder/disease, DD and heart failure with preserved/normal ejection
fraction. (Figure 1) shows details. We included randomized and
quasi-randomized designs, pre-post trials, cross-sectional studies, and
observational studies.