This research is conducted to determine whether the nurse-led Health Action Process Approach Model-based Cardiac Rehabilitation Program is effective in patients with myocardial infarction. The population of the study will consist of coronary angiography patients with myocardial infarction in the cardiology service of a state hospital. In this study, which is planned as a randomized controlled experimental model, 35 intervention and 35 control groups will be studied. As data collection tools; patient identification form, Laboratory Investigations Monitoring Form, Perceived Stress Scale, Health Action Process Approach Based Participant Assessment Form, Health Action Process Approach Based Myocardial Infarction Risk Factors Participant Assessment Form Functional Capacity Assessment Form, Myocardial Infarction Dimensional Assessment Scale and Turkish Modified Morisky Scale will be used. Health Action Process Approach Modeled Cardiac Rehabilitation Program will be applied to the intervention group and no intervention will be applied to the control group. Data will be collected with data collection tools at 6, 12, 24 weeks. SPSS 25.0 (Stastical Package for Social Science) package program will be used for statistical analysis of the data. Descriptive statistics will be given as number, percentage, mean, standard deviation and median values. The normal distribution of the data of numerical variables will be evaluated by Shapiro Wilk test. Two group comparisons will be made with independent two sample t-test for normally distributed variables and with Mann-Whitney U test for variables that do not show normal distribution. Comparisons of the groups' pre-test, week 6, week 18 and week 24 scale scores will be made with two-way analysis of variance in repeated measures from general linear models.

Inclusion Criteria:

• To be between 18-70 years old,
• Becoming literate,
• Living in the city center
• Having had a heart attack within the last month,
• Not having had a heart attack before,
• Dyspnea less than 4-5 degrees according to the modified Borg Scale
• No deformity or diagnosis related to the musculoskeletal system that may prevent physical activity, no orthopedic limitation
• Stable New York Heart Association (NHYA) functional class I or II coronary artery disease with myocardial infarction

Exclusion Criteria:

Those with communication disabilities such as speech, vision, hearing

• Dyspnea score of more than 4-5 degrees according to the modified Borg Scale
• Those who stayed in intensive care for a long time after MI
• Complications related to treatment and interventions after MI
• Those who underwent surgical treatment after MI,
• Those with chronic diseases (chronic obstructive pulmonary disease, chronic renal failure, hypertension, diabetes, pulmonary emphysema, rheumatic valve disease, cancer diagnosis, etc.)
• Those who indicated that they would not participate in intervention programs due to time constraints.
• Failure of the six-minute walk test