The Elusive Clot: The Controversy over Coronary Thrombosis in Myocardial Infarction

After Heberden's description of patients with "angina pectoris" in 1768, for over 125 years most physicians believed that the disease was immediately fatal. The growing realization early in the twentieth century that in fact patients could survive an acute myocardial infarction led to a search for mechanisms and treatment. Coronary thrombosis was the primary candidate for the inciting event, but this supposition was based on rather piecemeal and uncritical reports. It became apparent that coronary thrombosis and acute myocardial infarction (AMI), terms that had often been used interchangeably, actually represented separate pathological entities. A few physicians even proposed that AMI caused coronary thrombosis rather than the other way around. The reasons for some investigators rejecting the coronary thrombosis hypothesis were ultimately shown to be the result of faulty pathological techniques and interpretations. This debate ended only when in vivo studies (i.e., coronary arteriography in living patients during AMI episodes) finally settled the matter. These events indicate that older theories, even when derived from faulty reasoning or poorly substantiated documentation, might ultimately prove valid. Newer investigative techniques can suddenly clarify issues that have previously seemed irresolvable. The identification of coronary thrombosis in AMI has led to major advances in the treatment of this serious and ubiquitous disease.