Is your spouse a pain in the ass or does he/she/it give you heart palpitations? If it's the latter, watch out. Your life might depend on you and your spouse fixing your marriage. OK, that's a tenuous finding of the research, but there is this:
Over the following 12 years, 589 participants had heart attacks or other heart problems. Those with the highest negative scores on the questionnaire had the highest risks, even taking into account other factors related to heart disease such as obesity, high blood pressure and smoking.Keep in mind, though, that married people fare better than single people, no matter what a pain in the patoot he or she might be.
Quality of life wise, try to have a good marriage. It's just better than a bad one. (And, yes, that advice was free.)