Hi there @Vesna EGarden, 

Thanks for sharing your question with us, happy to help! 

 
The "Default Title" variant is is built as a hidden placeholder in a store’s backend for any item that was not given a variant title, and therefore automatically synced to Klaviyo. 

While there is no way to prevent or purge just these “Default Title” items, you can use our if-else tags to filter them out of templates. For example, within a template with the catalog lookup tag, you can use the following syntax to skip over any items titled "Default Title":

{% if catalog_item.variant.title != 'Default Title' %} {{ catalog_item.variant.title }} {% endif %}

 
Thanks for participating in the Community!

-Taylor 

Thank you so much @Taylor Tarpley 

It works perfectly now. Just in case someone else need it, here is what fits for me:  

{{ item.product.title }}

{% if item.product.variant.title != 'Default Title' %} {{ item.product.variant.title }} {% endif %}

Quantity: {{ item.quantity|floatformat:0 }} — Total: {% currency_format item.line_price|floatformat:2 %}