What is best method to get GetItemsWithUniquePermissions count from SharePoint 2013 using client context (CSOM)?

I’m converting Event receiver codes into Remote event receiver using SharePoint 2013 Client context. I need to get list items with unique permissions count to validate while creating new document in certain site collections

It is possible using SharePoint object model

SP.List.GetItemsWithUniquePermissions().Count()

I written the below logic to get list items with unique permissions count in CSOM but it is throwing timeout exception

var items = list.GetItems(CamlQuery.CreateAllItemsQuery());
            ctx.Load(items, icol => icol.Include(i => i.RoleAssignments.Include(ra => ra.Member), i => i.DisplayName));
            ctx.ExecuteQuery();
            List<string> uniqitem = new List<string>();
            foreach (var item in items)
            {
                foreach (var assignment in item.RoleAssignments)
                {
                    uniqitem.Add(assignment.Member.Title);
                }
            }
            int itemCount = uniqitem.Distinct().Count();

Could you please suggest me the right method in CSOM ? Thanks in advance

Thanks, it is slight faster now

var items = list.GetItems(CamlQuery.CreateAllItemsQuery());
ctx.Load(items, col => col.Include(i => i.HasUniqueRoleAssignments));
ctx.ExecuteQuery();
int itemCount = items.Where(i => i.HasUniqueRoleAssignments).Count;