ABSTRACT
Background: Vein graft thrombosis is the leading cause of acute graft failure within the first post-operative month. Several studies have shown the benefit of post-operative dual anti-platelet therapy (DAPT) in preventing acute graft thrombosis. The purpose of this study was to determine whether peri-operative initiation of DAPT will improve short and intermediate term graft patency. Methods: This was a randomized, double-blind, placebo controlled trial of 20 patients undergoing CABG to compare DAPT versus aspirin monotherapy. The primary outcome was post-operative graft patency at 2 and 52 weeks determined by <50% bypass graft stenosis by cardiac computed tomography angiography (CCTA). The secondary outcomes were (1) major adverse cardiovascular events (MACE), defined as myocardial infarction, thrombotic events, and angina, and (2) safety end-points defined as TIMI major and minor bleeding events. Results: The study population consisted predominately of men (19/20 patients). At 2 weeks, all LIMA grafts were patent although vein graft patency for the DAPT group was only 83.3% (20/24) compared to 89.5% (17/19) for placebo (p=0.597). At 52 weeks, the patency rate in the placebo group was 52.6% (10/19) as compared to a patency of 71.4% (15/24) in the dual anti-platelet therapy arm (p=0.244). Conclusion: The addition of clopidogrel to aspirin post-bypass surgery did not significantly improve venous graft patency at 2 weeks but trended toward higher graft patency at 52 weeks.
ABSTRACT
Coronary heart disease (CHD) is highly prevalent in patients with diabetes mellitus (DM), and remains the single most common cause of death among this population. Regrettably, a significant percentage of diabetics fail to perceive the classic symptoms associated with myocardial ischemia. Among asymptomatic diabetics, the prevalence of abnormal cardiac testing appears to be high, raging between 10% and 62%, and mortality is significantly higher in those with abnormal scans. Hence, the potential use of screening for CHD detection among asymptomatic DM individuals is appealing and has been recommended in certain circumstances. However, it was not until recently, that this question was addressed in clinical trials. Two studies randomized a total of 2,023 asymptomatic diabetics to screening or not using cardiac imaging with a mean follow up of 4.4 ±1.4 yrs. In combination, both trials showed lower than expected annual event rates, and failed to reduce major cardiovascular events in the screened group compared to the standard of care alone. The results of these trials do not currently support the use of screening tools for CHD detection in asymptomatic DM individuals. However, these studies have important limitations, and potential explanations for their negative results that are discussed in this manuscript.
La enfermedad de la arterias coronarias (EAC) es muy prevalente en pacientes con diabetes mellitus (DM), y continúa siendo la principal causa de muerte en estos pacientes. Desafortunadamente, muchos diabéticos pueden carecer de síntomas de alerta en la presencia de isquemia miocárdica, por lo cual el diagnóstico de EAC puede ocurrir de manera tardía. Estudios observacionales han sugerido que la prevalencia de isquemia miocárdica puede ser alta en diabéticos asintomáticos (10 al 62% según la serie) y la mortalidad es mayor en esos pacientes. Por esto, el uso de pruebas para detección de EAC en el paciente diabético asintomático parece atractivo y es recomendado en ciertas circunstancias. Sin embargo, no fue si no hasta hace poco que dos estudios investigaron el verdadero rol de estas pruebas de manera randomizada. En conjunto, 2,023 pacientes diabéticos asintomáticos fueron aleatorizados a recibir o no una prueba para detección de EAC y fueron seguidos en promedio por 4.4 ±1.4 años. Al final de seguimiento, ambos estudios mostraron menos eventos cardiovasculares de los esperados, y el uso de pruebas para detección de EAC no redujo la tasa de eventos cardiovasculares comparado al no uso de estas pruebas. Los resultados de estos ensayos clínicos no soportan actualmente el uso de estas pruebas en el paciente diabético asintomático. Sin embargo, estos estudios tienen limitaciones importantes, y posibles hipótesis para explicar los resultados que son discutidas en el artículo.