Stop auto load wp-admin admin-ajax.php

I have a multisite.
I want to stop autoload wp-admin/admin-ajax.php. As I have search in google. I have found out option heartbeat. But it reduced the request.

<?php 
add_action( 'init', 'my_deregister_heartbeat', 1 );
function my_deregister_heartbeat() {
global $pagenow;

if ( 'post.php' != $pagenow && 'post-new.php' != $pagenow )
    wp_deregister_script('heartbeat');
} 
?>

But I want to completely stop autoload wp-admin admin-ajax.php. As autoload wp-admin admin-ajax.php increase my cpu usage limit to 70 to 80%.

So is there any option to stop autoload wp-admin admin-ajax.php request.