A Higher-Than-Standard-Intensity International Normalized Ratio Goal for Patients Undergoing Mechanical Aortic Valve Replacement With Additional Thrombotic Risk Factors: Protocol for a Systematic Review and Meta-Analysis - Myung-Rho Kim; Taha Shaikh; Shawn Wang; Spencer Taylor; Vidhani Goel; Banveet Kaur Khetarpal; Chowdhury Ahsan; Kavita Batra (JMIR Research Protocols)