[Circadian variation in the effectiveness of reperfusion therapy in ST-segment elevation myocardial infarction treated with primary angioplasty and circadian associations with prognosis]. / Variabilidad circadiana de la efectividad de la técnica de reperfusión y del pronóstico del infarto de miocardio con elevación del ST tratado mediante angioplastia primaria.

OBJECTIVES: To explore circadian variation in the effectiveness of percutaneous transluminal coronary angioplasty (PTCA) to treat ST-elevation myocardial infarction (STEMI) To explore the effects of circardian variation on infarct extension and in-hospital complications. MATERIAL AND METHODS: Observational retrospective cohort study including patients with PTCA-treated STEMI in a tertiary care university hospital between March 2003 and August 2009. The independent variable of interest was the time of onset of STEMI symptoms, grouped in 6-hour time frames. The main outcome variable was PTCA effectiveness. Secondary outcome variables were infarct extension and the presence of in-hospital complications. RESULTS: A total of 522 patients records were studied. The mean (SD) age was 62.3 (13.6) years and 404 (77.4%) were men. The largest proportion of PTCA-treated STEMI cases first experienced symptoms between 6 AM and 12 PM (201 cases, 38.5%) (P<.001). PTCA was ineffective in 122 (23.4%). The 6 AM to 12 PM time frame was an independent predictor of PTCA ineffectiveness (odds ratio, 1.79; 95% CI, 1.09-2.94; P=.012). Onset in this interval was also associated with infarct extension but not with in-hospital complications. CONCLUSION: A time of onset of STEMI between 6 AM and 12 PM predicts the ineffectiveness of PTCA and greater infarct extension but not in-hospital complications.

OBJETIVO: Estudiar la presencia de un patrón de variabilidad circadiana en la efectividad del tratamiento con angioplastia coronaria transluminal percutánea (ACTPp) del infarto agudo de miocardio con elevación del segmento ST (IAMCEST), así como su relación con la extensión del infarto y la presencia de complicaciones intrahospitalarias. METODO: Estudio observacional de cohortes retrospectivo que incluyó a pacientes con IAMCEST tratados con ACTPp en un hospital terciario universitario entre marzo 2003 y agosto 2009. La variable de estudio fue la hora de inicio de los síntomas del IAMCEST, agrupando en periodos de riesgo cronobiológico de 6 horas. La variable de resultado principal fue la efectividad de ACTPp. Las variables de resultado secundarias fueron la extensión del infarto y la presencia de complicaciones intrahospitalarias. RESULTADOS: Se incluyeron 522 pacientes con una edad media de 62,3 (DE 13,6) años, de los cuales 404 (77,4%) fueron hombres. La franja horaria entre las 6-12 h fue la que presentó una mayor frecuencia de IAMCEST tratado con ACTPp (201 casos, 38,5%) (p < 0,001). Del total, 122 casos (23,4%) mostraron una ACTPp no efectiva. La franja horaria de 6-12 h fue un factor independiente de ACTPp no efectiva (OR 1,79; IC95% 1,09-2,94; p = 0,012). Además, se asoció con la extensión del infarto, aunque no con la presencia de complicaciones durante el ingreso hospitalario. CONCLUSIONES: La hora de inicio de infarto de miocardio, en la franja de 6-12 h, es un predictor independiente de ACTPp no efectiva y de una mayor extensión del infarto, pero no de complicaciones intrahospitalarias.

Usefulness of Rabbit Anti-thymocyte Globulin in Patients With Giant Cell Myocarditis.

Giant cell myocarditis (GCM) is an aggressive inflammatory myocardial disease. Immunosuppression is an effective treatment for some cases. However, the duration of action of agents such as muromonab CD3 is short and others such as the calcineurin inhibitors may lead to renal failure. Here we describe the outcome of a novel approach to treatment using rabbit anti-thymocyte globulin (RATG). A retrospective analysis of 6 patients treated with RATG for GCM was performed. Diagnosis was confirmed by endomyocardial biopsy, and RATG was administered with a high dose of corticosteroids. None of the patients had cytokine release syndrome or leukopenia, and 5 had thrombocytopenia (2 of them severe). Only 1 had a serious bleeding event that occurred after implantation of mechanical circulatory support. None developed impaired renal function after the treatment. Five were successfully discharged home with an increase in global left ventricular ejection fraction of 29%. Four are currently alive without recurrent disease, 1 of them after heart transplantation, with a mean follow-up of 970 days (423 to 1,875 days), left ventricular ejection fraction of 53%, and all in current New York Heart Association Classification class ≤II. Only 1 case had GCM recurrence. There were 2 deaths: one because of intracranial bleeding after mechanical circulatory support implantation and the other caused by primary graft dysfunction. In conclusion, patients with GCM can be successfully immunosuppressed with RATG and corticosteroids, thereby avoiding renal impairment. Early thrombocytopenia is the main adverse event. Larger cohorts of patients are necessary to compare the different immunosuppressant strategies available for GCM in a randomized fashion.

Circadian variations of infarct size in acute myocardial infarction.

BACKGROUND: The circadian clock influences a number of cardiovascular (patho)physiological processes including the incidence of acute myocardial infarction. A circadian variation in infarct size has recently been shown in rodents, but there is no clinical evidence of this finding. OBJECTIVE: To determine the impact of time-of-day onset of ST segment elevation myocardial infarction (STEMI) on infarct size. METHODS: A retrospective single-centre analysis of 811 patients with STEMI admitted between 2003 and 2009 was performed. Infarct size was estimated by peak enzyme release. The relationship between peak enzyme concentrations and time-of-day were characterised using multivariate regression splines. Time of STEMI onset was divided into four 6-hour periods in phase with circadian rhythms. RESULTS: Model comparisons based on likelihood ratio tests showed a circadian variation in infarct size across time-of-day as evaluated by peak creatine kinase (CK) and troponin-I (TnI) concentrations (p=0.015 and p=0.012, respectively). CK and TnI curves described similar patterns across time, with a global maximum in the 6:00-noon period and a local minimum in the noon-18:00 period. Infarct size was largest in patients with STEMI onset in the dark-to-light transition period (6:00-noon), with an increase in peak CK and TnI concentrations of 18.3% (p=0.031) and 24.6% (p=0.033), respectively, compared with onset of STEMI in the 18:00-midnight period. Patients with anterior wall STEMI also had significantly larger infarcts than those with STEMI in other locations. CONCLUSIONS: Significant circadian oscillations in infarct size were found in patients according to time-of-day of STEMI onset. The infarct size was found to be significantly larger with STEMI onset in the dark-to-light transition period (6:00-noon). If confirmed, these results may have a significant impact on the interpretation of clinical trials of cardioprotective strategies in STEMI.