thrombus formation following Acute coronary after stress testing percutaneous transluminal coronary angioplasty

Summary Successful percutaneous transluminal coronary angioplasty (PTCA) was performed on a 37-year-old white man with an isolated 95% right coronary artery stenosis who initially presented with type 11 unstable angina. Submaximal treadmill stress testing was not carried out before PTCA, but testing 3 days after PTCA was strongly positive without accompanying symptoms of myocardial ischaemia. Some 30 min­ utes after this test the patient experienced severe precordial pain with features of a hyperacute trans­ mural inferior myocardial infarction. Immediate coro­ nary arteriography delineated fresh thrombus related to the previous PTCA site. Intracoronary thrombolysis with streptokinase was successful, revealing an underlying severe stenosis at the PTCA site. PTCA was not repeated, nor was emergency coronary artery bypass grafting (CABG) performed. This is the second such case documented in the literature; the first patient failed to respond to intracoronary throm­ bolysis with streptokinase and was submitted to emergency CABG. The possible underlying patho­ physiological mechanisms are discussed. We believe that the late thrombus formation was directly related to submaximal stress testing after successful PTCA, and recommend that testing to assess the efficacy of PTCA be deferred until at least 1 month after the procedure to allow for completion of the healing process. S AIr Med J , 985; 67: 378-382.