Has he had the surgery yet? Lavender is a heavenly color, but the skulls are only reminding him that death means no more flesh. It's surely a big thought to have to leave your wife, I know it well. If there is any secret higher insight or guidance in this dream, it would be found by exploring the differences between his real awareness and the dream content. The dream's imagery could suggest that rising up to heaven could be very sweet--as in the lavender color and its heavenly aroma, but it's entering a fleshless home of the dead, and leaving you behind. In traditional masculine thinking he's aware of not wanting to leave YOU alone, but not aware that he'd be leaving alone himself, while you would not be without human company. So you are the MOST IMPORTANT PERSON to him, and the only one he's mightily does not want to leave behind him.
These moments of intimate words at the edge of life are very precious; you are blessed to share them.
Heart surgery can feature closeness to death--I've had it before such surgery myself. The body can accurately display in dreams such invasive surgery when it's happening. but in advance it's more likely vague premonitions and not clear warnings. So what he dreamt is more about how he felt about it than about what was going to happen.