Ranolazine for improving coronary microvascular function in patients with nonobstructive coronary artery disease: a systematic review and meta-analysis with a trial sequential analysis of randomized controlled trials.

"Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-23-1029/coif). All authors reported that this work was supported by grants from the Beijing Municipal Natural Science Foundation (grant no. 7212068) and the National Natural Science Foundation of China (grant no. 81900747). The authors have no other conflicts of interest to declare."

"Funding: This work was supported by grants from the Beijing Municipal Natural Science Foundation ( grant no. 7212068 ) and the National Natural Science Foundation of China ( grant no. 81900747 )."

"Cochrane Library, PubMed, Embase, China National Knowledge Infrastructure (CNKI), and the Chinese BioMedical Literature Database (CBM) were searched for published RCTs in English or Chinese languages. The keywords were “ranolazine”, “late sodium channel blocker”, “nonobstructive coronary artery disease”, “ischemia with nonobstructive coronary arteries”, “coronary microvascular dysfunction”, “microvascular angina”, “angina with nonobstructive coronary arteries”, “microcirculatory function”, and “cardiac syndrome X”. We conducted our final searches on the databases on the following dates: the Cochrane Library on September 29, 2023; PubMed on September 30, 2023; Embase on September 30, 2023; CNKI on September 30, 2023; and CBM on September 30, 2023. Furthermore, in our pursuit of comprehensive data collection, we made a concerted effort to include potentially relevant studies that might have reported negative results. To this end, we extended our search to gray literature databases, specifically OpenGrey and the Healthcare Management Information Consortium (HMIC). This strategy was instrumental in ensuring the breadth and inclusivity of our research scope. The search terms are listed in detail in Table S1. The meta-analysis protocol and systematic search strategy are registered in PROSPERO (International Prospective Register of Systematic Reviews; registration ID: CRD42022298144)."