If you ages 18 and older AND have either heart failure (in the past 2 years) or a heart attack (in the past year) you may qualify for a research study. What happens in the study? • vaccination with either high dose (investigational for adults under the age of 65) OR standard dose flu shot, provided at no cost to you (once per year, up to 3 years); •monitoring any heart or lung related hospital visits; • telephone follow-up • optional blood draw. Patients who have already received their flu shot this year are not eligible to enroll. Participants will be compensated. For more information about how you can participate in INVESTED, please call the UAB Hypertension Program at 205-934-9281.