Hi, Thank you for the query and Welcome to HCM community. This incident can be explained from the psychosocial aspect of cardiovascular diseases. Angioplasty was an acute stressful event in yours fathers life. Post-MI patient often develop various psychological problems like anxiety, depression, anger, hostility and so on. A person who once had a stable personality, can become angry with a long lasting episode of anger after MI. And this anger can affect the heart very detrimentally and can act as a risk factor for further cardiac events. Consulting with a psychologist may be of great help. Often these patients get benefit from lifestyle advice, psychotherapy etc. Hope, this helps.