Over-zealous doctors are one of the major causes of death after a heart attack. Their aggressive interventions - such as angioplasty and clot-dissolving drugs - double the chances of the patient dying after he has survived a heart attack or heart failure. It's all to do with timing, researchers from the Quebec Healthcare Assessment Agency in Montreal have discovered. Aggressive treatments on the heart-attack patient are supposed to be carried out within a very short time of him being admitted to hospital. Done immediately, the interventions can be life-savers - but even a delay of a few minutes can kill the patient. Techniques such as angioplasty are supposed to be carried out within 90 minutes, but the researchers discovered that 68 per cent of the operations took place after that optimum time, and clot-dissolving drugs were given after the recommended 30-minute window in 54 per cent of cases. As a result, the patients given late treatment were twice as likely to die as those given the same treatments within the recommended timeframe. (Source: Journal of the American Medical Association, 2010; 303: 2148).