Is a person with vitamin K deficiency at a lower risk for having a heart attack because he clots poorly?

Almost . . . I can see the logic in that question, since we often prescribe mild blood-thinners (e.g., aspirin) to prevent coronary clots. However, someone with a pronounced enough vit. K deficiency to prevent coagulation may begin spontaneously hemorrhaging elsewhere (particularly in the GI tract or the brain); and if the hemodynamic state in the body is disrupted, the heart may still become ischemic.