Relative safety and complication profiles of thrombolysis and primary angioplasty in acute myocardial infarction

The safety profile of thrombolytic therapy has been evaluated by several large-scale clinical trials; data on percutaneous coronary angioplasty (PTCA) complications in the context of acute myocardial infarction is more limited. The major life-threatening complication of thrombolytic therapy is cerebral haemorrhage, with an overall incidence of 0.7-1%, but with higher rates in the elderly, hypertensives or patients on anticoagulant therapy, or patients with a previous stroke. Non-life-threatening bleeds occur in 4-20% depending on definition and on whether or not invasive vascular procedures are involved. Allergic reactions occur in 5-7% but are seldom severe. There is a small but significant increase in the risk of cardiac rupture or ventricular septal defect. PTCA-related complications can be divided into cardiac and non-cardiac. Cardiac complications include arrhythmias, coronary dissection and abrupt coronary closure. However, since the starting point in primary PTCA is usually a completely closed vessel, the incremental damage is small. Thrombus displacement to another coronary artery, or left main or proximal right coronary dissection are serious but rare (<1%). Delayed abrupt closure probably occurs in 5-10%, but may be silent. Restenosis occurs in 30-40%, but very rarely leads to reinfarction. Cif non-cardiac complications, cerebral haemorrhage is rare, but embolic stroke may occur. Large volumes of radiographic contrast may be used, and radiation exposure may be substantial in prolonged procedures, but documented adverse events are uncommon. Vascular access problems (bleeding, ischaemia) occur in 5-10%. Vascular problems are much more common when PTCA is performed after thrombolysis.