Endothelial-dependent vasoconstriction in the infarct-related artery early after myocardial infarction is smaller following primary angioplasty than thrombolytic therapy.

INTRODUCTION AND OBJECTIVES: In patients with ST-elevation acute myocardial infarction treated by thrombolysis, both early endothelial dysfunction and long-term improvement in the infarct-related artery have been reported. Our aims were to assess the degree of endothelial dysfunction present after primary angioplasty and to compare it with that after thrombolysis. METHODS: Endothelial function was assessed 9 days after infarction by infusing acetylcholine, at an increasing concentration, and subsequently nitroglycerine into the infarct-related artery in 16 patients who had undergone primary angioplasty and bare-metal stent implantation. In addition, endothelial function was compared with that in a group of 16 patients treated by thrombolysis in a different time period. The mean change in the diameters of segments distal to the culprit lesion or the treated lesion were evaluated by quantitative coronary angiography. RESULTS: Baseline characteristics were similar in the two groups, except that patients in the primary angioplasty group were treated with clopidogrel and there were differences in residual stenosis in the infarct-related artery (3% in the primary angioplasty group compared with 62% in the thrombolysis group). At the maximum acetylcholine concentration, the degree of vasoconstriction was less in the primary angioplasty group than in the thrombolysis group (-4+/-5% vs. -20+/-21%; P=.018). CONCLUSIONS: Early endothelium-dependent vasoconstriction in the infarct-related artery was lower in acute myocardial infarction patients treated by primary angioplasty and bare-metal stent implantation than in those treated by thrombolysis.

Menor vasoconstricción precoz dependiente del endotelio en la arteria que causa el infarto tras angioplastia primaria en comparación con trombolisis después de un infarto agudo de miocardio / Endothelial-Dependent Vasoconstriction in the Infarct-Related Artery Early After Myocardial Infarction Is Smaller Following Primary Angioplasty than Thrombolytic Therapy

Introducción y objetivos. En pacientes con un infartoagudo de miocardio con elevación del ST tratado contrombolisis, se ha documentado una disfunción endotelialprecoz de la arteria que causa el infarto, así como unamejoría de ésta a largo plazo. Nuestro objetivo fue valorar el grado de disfunción endotelial después de una angioplastia primaria y en comparación con la trombolisis.Métodos. La función endotelial fue valorada 9 díasdespués del infarto infundiendo acetilcolina a concentraciones crecientes y luego nitroglicerina en la arteria origen del infarto de 16 pacientes tratados con angioplastia primaria e implante de stent metálico. La función endotelial fue comparada con la de un grupo de 16 pacientes tratados con trombolisis en otro momento. Evaluamos los cambios medios en el diámetro de los segmentos distales a la lesión causal o tratada, mediante angiografía coronaria cuantitativa.Resultados. Las características basales fueron similaresen ambos grupos, a excepción del tratamiento conclopidogrel en el grupo de angioplastia primaria y la estenosis residual de la arteria origen del infarto (del 3% en el grupo de angioplastia primaria frente al 62% del grupo de trombolisis). Con la concentración máxima de acetilcolina, el grupo tratado con angioplastia primaria mostró menor vasoconstricción que el grupo tratado con trombolisis (–4 ± 5% frente a –20 ± 21%; p = 0,018).Conclusiones. Los pacientes con un infarto agudode miocardio tratados con angioplastia primaria e implante de stent metálico tienen menor vasoconstricciónprecoz dependiente del endotelio que los tratados contrombolisis

Introduction and objectives. In patients with STelevationacute myocardial infarction treated bythrombolysis, both early endothelial dysfunction and longterm improvement in the infarct-related artery have been reported. Our aims were to assess the degree ofendothelial dysfunction present after primary angioplastyand to compare it with that after thrombolysis.Methods. Endothelial function was assessed 9 daysafter infarction by infusing acetylcholine, at an increasing concentration, and subsequently nitroglycerine into the infarct-related artery in 16 patients who had undergone primary angioplasty and bare-metal stent implantation. In addition, endothelial function was compared with that in a group of 16 patients treated by thrombolysis in a differenttime period. The mean change in the diameters ofsegments distal to the culprit lesion or the treated lesion were evaluated by quantitative coronary angiography.Results. Baseline characteristics were similar in the twogroups, except that patients in the primary angioplastygroup were treated with clopidogrel and there weredifferences in residual stenosis in the infarct-related artery (3% in the primary angioplasty group compared with 62% in the thrombolysis group). At the maximum acetylcholine concentration, the degree of vasoconstriction was less in the primary angioplasty group than in the thrombolysis group (–4±5% vs. –20±21%; P=.018).Conclusions. Early endothelium-dependentvasoconstriction in the infarct-related artery was lower in acute myocardial infarction patients treated by primary angioplasty and bare-metal stent implantation than in those treated by thrombolysis