CF7 – Create a selectbox from database?

Hi guys,
I am trying to create a custom dropdown (select) box in my Contactform 7 with custom table from ai1ec_events table.
this is my code but i have a problem because return only pagetitle field, not correct value.

can you help me, please?

wpcf7_add_shortcode('postdropdown', 'createbox', true);
function createbox(){
global $wpdb;
$campocustom = $wpdb->get_results( "SELECT * FROM db_ippbrescia.wpipp_ai1ec_events WHERE contact_name IS NOT NULL AND contact_name != '';" );
$output = "<select name='contact_name' id='contact_name' onchange='document.getElementById(\"cursus\").value=this.value;'><option></option>";
foreach ( $campocustom as $post ) : setup_postdata($post);
$title = get_the_title();
$output .= "<option value='$title'> $title </option>";
endforeach;
$output .= "</select>";
return $output;
}