While you are angry, the arteries supplying oxygen-rich blood to your heart are also narrowing, and your blood is "sticker" (more viscous) and more likely to form dangerous blood clots.
Blood clots could lead to a heart attack or stroke. A heart attack could also be triggered if hormones released during anger (for example, adrenaline) cause an irregular heart rhythm (arrhythmia).
Furthermore, anger has been linked to risk factors such as higher homocysteine levels and higher cholesterol levels. Therefore, learning anger management techniques could help reduce the stress on your cardiovascular system and ultimately save your life.
Next time, if you want to get angry with someone or anything, do think twice!