It has the added benefit of risk stratifying the patient because you know the status of the other coronaries. Reocclusion is very uncommon. After a myocardial infarction, patients are generally observed in the hospital for 3-5 days. This is because this is the time period when they are most at risk for complications following their infarction. Your patient is doing well until day 4 when she suddenly decompensates with cardiogenic shock.
Mechanical complications are uncommon, but carry a high fatality rate.
They are one of the most dramatic things you will see in medicine. Tricuspid insufficiency would not cause sudden hemodynamic collapse. The two possibilities are VSD or mitral insufficiency. Emergency surgery is the only treatment for either of these two conditions. Without surgery, the patient will die.