If your card details had been stolen your account would already be empty, so there would be no point in the thieves sending you an email.
The worst that might have happened is that someone has identified you as a person who shops on Italian websites using a visa card (but without any knowledge of the actual card details). Given the tracking technology that's used across most commercial websites, that's quite likely to have happened. It's little different to the ads you see here on AB matching your recent browsing habits except that, rather than paying for advertising based upon knowledge of your browsing habits, someone has sent you an email for the same purpose.
Chris