Use WP_Query with have_posts()?

Is it possible to use

$items = new WP_Query( $query_args ); 

with

<?php if(have_posts()): ?>
<?php while (have_posts()) : the_post(); ?>

without changing the loop to be

<?php while ($items->have_posts()) : $items->the_post();

Thanks.

global $wp_query;
$original_query = $wp_query;
$wp_query = null;
$wp_query = new WP_Query( $args );
if ( have_posts() ) :
    while ( have_posts() ) : the_post();
        the_title();
        the_excerpt();
    endwhile;
else:
    echo 'no posts found';
endif;
$wp_query = null;
$wp_query = $original_query;
wp_reset_postdata();

http://codex.wordpress.org/Function_Reference/wp_reset_postdata