Corporate executives are typically expected to be able to shoulder any sort of burden. Employees look to them to make the right decisions about the direction of the company or to keep them safe from harm whilst they are at work, shareholders look to them to improve margins and bring about a share price increase... The list is a long one, and as such there are many groups who place a lot of expectation and demands upon senior managers and directors.
Of course many people will argue that it is an extremely well-paid and privileged position, and that with such rewards it is only natural to expect responsibility and heavy workloads. Even so, executives are still human after all, and will suffer variations of the same trials and tribulations that other workers experience. Similarly, just as line managers and workers can benefit from training courses and business coaching, so too can senior managers in the form of executive coaching.
These senior executives are unlikely to have "line managers" insofar as having someone available every day to discuss their concerns with. They may be responsible only to the head of the entire organisation, who may be situated in a different country and have little hands-on involvement with the actual running of the company, and so may not be available to speak to for days or weeks at a time. Executive coaching is indeed provided to many CEOs themselves, for which they often have nobody with whom they can really discuss their doubts about the strategy or the direction of the business for example, as they might be unwilling to convey such uncertainty to the board of directors.
Having an executive coaching session with an experienced business coach and mentor can prove to be highly beneficial for the executive, both in terms of helping them with corporate issues and in relieving some of the sense of isolation and sole accountability that can come with being a director or chief executive.