you can try my working code :
private void listView1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Up)
{
if(e.Alt==true){
//do your stuff
}
}
}
i use this code because i don't know why when i use :
(e.Keycode == Keys>up && e.Alt==true)
didn't work.