Juan Bustamante

Evolution of neutrophil apoptosis in septic shock survivors and nonsurvivors

PURPOSE The aims were to analyze the temporal evolution of neutrophil apoptosis, to determine the differences in neutrophil apoptosis among 28-day survivors and nonsurvivors, and to evaluate the use of neutrophil apoptosis as a predictor of mortality in patients with septic shock. MATERIALS AND METHODS Prospective multicenter observational study carried out between July 2006 and June 2009. The staining solution study included 80 patients with septic shock and 25 healthy volunteers. Neutrophil apoptosis was assessed by fluorescein isothiocyanate (FITC)-conjugated annexin V and aminoactinomycin D staining. RESULTS The percentage of neutrophil apoptosis was significantly decreased at 24 hours, 5 days, and 12 days after the diagnosis of septic shock (14.8% ± 13.4%, 13.4% ± 8.4%, and 15.4% ± 12.8%, respectively; P < .0001) compared with the control group (37.6% ± 12.8%). The difference in apoptosis between 28-day surviving and nonsurviving patients was nonsignificant (P > .05). The mortality rate at 28 days was 53.7%. The crude hazard ratio for mortality in patients with septic shock did not differ according to the percentage of apoptosis (hazard ratio, 1.006; 95% confidence interval, 0.98-1.03; P = .60). CONCLUSIONS During the first 12 days of septic shock development, the level of neutrophil apoptosis decreases and does not recover normal values. No differences were observed between surviving and nonsurviving patients.

El polimorfismo R753Q del toll-like receptor 2 se asocia a un aumento en el riesgo de sufrir endocarditis infecciosa

The ability to respond to the ligands of toll-like receptors (TLR) could be affected by single nucleotide polymorphisms in TLR codifying genes. The influence of the polymorphisms TLR2 (R753Q, R677W), TLR4 (D299G, T399I) and CD14 (C-159T) was consecutively studied in 65 patients with infective endocarditis. The control group (n=66) consisted of healthy volunteers. All the polymorphisms were genotyped by means of restriction analysis after their amplification. An association between endocarditis and variants of TLR2 R753Q (P <.001) was observed, but no association with other polymorphisms was found. The TLR2 R753Q co-dominant (odds ratio=13.33), recessive (odds ratio=9.12) and dominant (odds ratio=3.65) genotypes showed a positive association with the infective endocarditis phenotype. The polymorphism TLR2 R753Q was associated with a greater susceptibility towards the development of infective endocarditis. Further studies are required to validate these results and identify other genetic risk factors.

Cell saving systems do not reduce the need of transfusion in low-risk patients undergoing cardiac surgery.

OBJECTIVES Cell saving systems have been widely used to reduce blood loss and need of transfusions. These device are mainly indicated in complex cardiac surgery procedures and in those patients with a high risk of bleeding. However, it is not clear if there is a benefit of a cell saver (CS) system in low-risk patients undergoing cardiac surgery. Our aim was to analyze if the use of CS systems reduce the need of blood products in low-risk patients undergoing cardiac surgery. METHODS Between February and June 2009 all low-risk patients (EuroSCORE<10%) undergoing coronary or valve procedure were selected (n=63). Exclusion criteria were: combined procedure, aorta procedure, redo surgery, emergency procedures, creatinine levels>2 mg/ml, anemic patients and patients with a body surface area (BSA)<1.6 m2. Patients were randomized to undergo cardiac surgery with a cell saving system (group CS) (n=34) or without (control group, CO) (n=29). All patients received tranexamic acid during the procedure. Need of blood products and clinical outcomes were analyzed in both groups. RESULTS Mean age was 64.7±12.3 years old with 33% of female patients. Baseline clinical characteristics and preoperative blood count cell were similar in both groups. Mean CS blood reinfused was 461±174 ml (maximum: 985 minimum: 259). A total of 59 red blood packages were transfused in 25 patients (mean 1.02±1.3; range: 0-5). The proportion of patients being transfused was similar in both groups (CS: 40% vs. CO: 46.4%; P=0.79). Eleven plasma packages were transfused (CS: 8 vs. CO: 3; P=0.77) and three platelet pools were used in group CS and none in group CO (P=0.08). Multivariate analysis showed that preoperative hemoglobin levels>13.3 g/dl [relative risk (RR): 0.29; confidence interval (CI): 0.09-0.99] and BSA>1.74 (RR: 0.19; CI: 0.54-0.68) were protective against blood transfusion. CONCLUSIONS In low-risk patients CS system did not reduce the need of blood transfusion. Clinical outcomes were similar regardless of the use of a cell saver system. A low preoperative hemoglobin level and a low BSA were related with the use of blood products.

Adjustable Segmental Tricuspid Annuloplasty: Technical Advantages and Midterm Results

BACKGROUND Adjustable segmental tricuspid annuloplasty is a new recently published procedure. The purpose of this prospective study was to present the technical advantages of this new tricuspid annuloplasty and analyze its early and midterm results. METHODS Between January 2004 and December 2006, 17 patients who had moderate or severe pure functional tricuspid regurgitation (TR) underwent adjustable segmental tricuspid annuloplasty. The mean age of the patients was 64.3 +/- 10.4 years and the majority were female (94%). All patients had recent preoperative transthoracic echocardiography (TTE). Three postoperative TTE were performed: (I) before the hospital discharge; (II) between 3 and 6 months after surgery; and (III) at a mean 30.4 +/- 13.8 months of follow-up. We studied the tricuspid valve, right ventricle, and left ventricle. RESULTS No hospital mortality was reported. Progressive overall clinical improvement was observed. Serial postoperative TTE revealed the following: (1) 13 patients with mild or less than mild TR, 1 patient with residual moderate TR, 1 patient with early moderate TR related to poor left ventricular function, and 1 patient with late severe TR due to a transvenous pacemaker lead; (2) the indexed tricuspid annulus diameter normalized in all patients; (3) pulmonary hypertension gradually regressed; and (4) right ventricular end-diastolic diameter and inferior vena cava diameter gradually decreased throughout the study. CONCLUSIONS Adjustable segmental tricuspid annuloplasty is an improved and efficient procedure for functional TR because it is more selective, more adjustable and more resistant. It may be adversely influenced by poor left ventricular function and by the presence of a pacemaker lead.

Intraoperative PaO2 is not related to the development of surgical site infections after major cardiac surgery

BackgroundThe perioperative use of high inspired oxygen fraction (FIO2) for preventing surgical site infections (SSIs) has demonstrated a reduction in their incidence in some types of surgery however there exist some discrepancies in this respect. The aim of this study was to analyze the relationship between PaO2 values and SSIs in cardiac patients.MethodsWe designed a prospective study in which 1,024 patients undergoing cardiac surgery were analyzed.ResultsSSIs were observed in 5.3% of patients. There was not significant difference in mortality at 30 days between patients with and without SSIs. In the uni and multivariate analysis no differences in function of the inspired oxygen fraction administrated were observed.ConclusionsWe observed that the PaO2 in adult cardiac surgery patients was not related to SSI rate.

Restoration of atrial contractility after surgical cryoablation: clinical, electrical and mechanical results

To assess the electrical sinus rhythm (SR) recovery and the mechanical effectiveness of the atrial contraction by echocardiography is essential in patients undergoing atrial fibrillation (AF) surgery. Between September 2006 and May 2008, patients with chronic AF (n=33; permanent=23 or paroxysmal=10) underwent mitral surgery and surgical cryoablation for AF. Exclusion criteria were: AF that has persisted for 10 years and left atrium (LA) >65 mm. Echocardiography study was performed at six months after surgery. Mean age was 62 years (22 female, 11 male). Mean AF duration was three years (range 0.5-7.4). Mean atria size was 52.4+/-5.6 mm. Mitral valve surgery involved 32 prosthetic replacements and one mitral valve repair. There was no surgical mortality. Success rate for SR at three and six months was 90% and 82%, respectively. The only predictor of conversion to SR at six months was being at SR when discharge from the hospital. In patients in SR, echocardiographic study provided mechanical effectiveness of the atria in 100% of right atrium and 70% of the LA. Cryoablation for AF is an effective technique to recover electrocardiographic SR while being able to recover atrial contraction effectiveness.

Mitral insufficiency 30 years after resection of subvalvular aortic stenosis.

A 47-year-old woman who had been operated on 30 years earlier for a membranous type of subvalvular aortic stenosis presented with acute lung edema, rapid atrial fibrillation, and clinical signs of mitral regurgitation. Radiography of the thorax showed enlargement of the left cavities and signs of pulmonary congestion. Echocardiography revealed dilated left cavities, preserved left ventricular ejection fraction, and severe eccentric mitral regurgitation. This was confirmed by angiography that showed normal coronary arteries. At surgery, the mitral valve was found to have a perforation of approximately 1 cm in the anterior leaflet at the mitral-aortic continuity, and fibrous thickening of the leaflets with retraction of the free edges (Figure 1). The anterior mitral leaflet was resected and a prosthesis was implanted with sutures in the anterior section of the ring, placed around the upper area of the circular defect, achieving closure. Surgical resection of the aortic subvalvular fibrous ring (at the base of the septal mitral leaflet) may be complicated by mitral regurgitation through mitral valvular and mitral-aortic continuity lesions, even late after intervention.

Minimally Invasive Aortic Valve Surgery - New Solutions to Old Problems

Aortic stenosis is the most frequent valvulopathy in the western world and basically affects people over 60 years old. It is currently the most common cause of valve replacement in Europe and North America (Schmitto et al., 2011) and its incidence increases with age. (Lung et al., 2003) 25% of people over 65 suffer sclerosis of the aortic valve which can be detected in image tests such as echocardiography and 3% of those over 75 develop aortic stenosis (Lindroos et al., 1993; Stewart et al., 1997). Approximately 16% of patients with aortic valve sclerosis develop stenosis within the space of 7 years. (Cosmi et al., 2002) This rate of progression is variable and has been related with factors common to those for arterial sclerosis. The average reduction in the valve area has been stated as being around 0.1 cm2 per year. (Otto et al., 1997) and the annual increase in gradient as about 10 mmHg. Rheumatic etiology is not common in the more developed countries and its origin is usually degenerative. In approximately half of the cases there usually exists a bicuspid aortic valve basis. Bicuspid aortic valve valvulopathy affects 2% of the population (Kurtz & Otto, 2010) and constitutes the most frequent congenital anomaly. Aortic valve stenosis is more prevalent in men than women (Chambers et al., 2009). This disease normally remains asymptomatic for a long time and represents a low sudden death risk of less than 1%. When stenosis becomes symptomatic, however, the prognosis is much worse. The symptoms usually appear at the end of the disease with three of them being typical and each one of them determining a state which is both evolutionary and prognostic: dyspnea (due to heart faillure), angina and syncope. In aortic stenosis there coexist three physiological phenomena: cardiac ischemia, elevated pressure in the left ventricle and diminished cardiac output. Diminished tolerance to exercise is generally the first symptom of aortic stenosis and could be the result of the three previously mentioned phenomena. A careful medical history investigation is necessary in order to obtain this information as the earliest clinical signs may be insidious and may not be accompanied by dyspnea as such, and may be consciously or unconsciously disguised by the patient in the progressive restriction of their day-to-day activity as the disease develops.

Biodegradable collagen-elastin membrane as a pericardial substitute in coronary surgery.

In 1999 we reported the results of the first randomized clinical trial using a biodegradable collagen-elastin patch (OVI SA, Martillac, France) as a pericardial substitute.1 In this study, 25 patients undergoing surgical coronary revascularization received a membrane implant made of an elastin complex with bovine collagen reinforced with reabsorbable polygycolate mesh. Results showed no local or systemic inflammatory reaction or hemodynamic changes postoperatively. Now we report the case of one of these patients that received a pericardial substitute. Eighty-nine months after surgery, re-operation was required due to the development of aortic valvulopathy. After reopening the sternum (Figure 1), surgical exploration showed a neo-pericardium consisting of a solid, well-defined, membranous laminate, which was greyish in color and approximately 1 mm thick. The membrane uniformly enveloped the epicardium and was clearly distinguishable. Anatomic dissection positions were well defined; a small number of loose, easily removed adhesions by digital dissection were present. There was no evidence of constriction, restriction, or inflammatory reaction in the epicardium, making the identification of mediastinal structures and by-pass conduits relatively easy. Upon histological analysis of the membrane (Figure 2), bands of collagenized, fibrous tissues were observed with isolated collections of a sparse inflammatory cell infiltration of multinucleated giant cells and a foreign body-type inflammatory reaction, composed of lymphocytes, plasma cells, and histiocytes. In previous laboratory tests, it was found that peptides released during the degradation of the collagen-elastin complex inhibited native elastase and collagenase activity and minimized the local inflammatory response. Reabsorption of the collagen-elastin material occurs simultaneously with the synthesis of a neo-pericardium, with the patch acting as a framework to facilitate the incorporation of mesothelium-like cells on the epicardial face of the patch.2 In patients with a history of coronary artery bypass grafting (CABG), the requirement for a repeat CABG is dependent upon progression of atherosclerotic disease and the stability and patency of vein grafts. The necessity for re-operation increases progressively and has a direct relationship with the time elapsed since surgery. The need for a second myocardial revascularization after 5, 10, 15, and 20 years is reported to be approximately 4, 12, 27, and 40%, respectively.3 The most accepted opinion is that reoperations are associated with an increase in morbidity and mortality not only derived from patient-specific clinical factors (ie, older age and increased comorbidities) but also from the complexity Letters to the editor

Membrana biodegradable de colágeno-elastina como sustituto pericárdico en cirugía coronaria

En 1999 presentamos los resultados del primer ensayo clínico aleatorizado en el que se utilizó un parche biodegradable de colágeno-elastina (OVI SA, Martillac, Francia) como sustituto pericárdico. En dicho estudio 25 pacientes sometidos a revascularización miocárdica quirúrgica recibieron como sustituto pericárdico un parche formado por un complejo de elastina y colágeno bovino reforzado con una malla reabsorbible de poliglucolato. Los resultados obtenidos no indicaron ninguna reacción inflamatoria local o sistémica ni alteraciones hemodinámicas postoperatorias. Describimos ahora el caso de uno de esos pacientes en el que se utilizó el sustituto pericárdico. A los 89 meses de la operación, fue necesaria una reintervención a causa de la aparición de una valvulopatía aórtica. Tras reabrir el esternón (fig. 1), la exploración quirúrgica mostró un neopericardio formado por una lámina membranosa sólida y bien definida, de color grisáceo y un grosor de 1 mm aproximadamente. La membrana envolvía de manera uniforme el epicardio y era claramente diferenciable. Los puntos de disección anatómica estaban bien definidos. Había un número reducido de adherencias, que se pudo despegar con facilidad mediante disección digital. No había signos de constricción, restricción o reacción inflamatoria en el epicardio, lo cual hizo que la identificación de las estructuras mediastínicas y los injertos de bypass fuera relativamente sencilla. En el análisis histológico de la membrana (fig. 2), se observaron bandas de colágeno y tejido fibroso con acumulaciones aisladas de un infiltrado inflamatorio con células gigantes multinucleadas y una reacción inflamatoria de tipo cuerpo extraño formada por linfocitos, células plasmáticas e histiocitos, como se observa en la parte aumentada de la tinción. En pruebas de laboratorio previas, se observó que los péptidos liberados durante la degradación del complejo de colágeno-elastina inhibían la actividad de colagenasa y elastasa nativas y reducían al mínimo la respuesta inflamatoria local. La reabsorción del material de colágeno-elastina se produce de manera simultánea a la síntesis de neopericardio, de tal manera que el parche actúa como estructura básica para facilitar la incorporación de células de tipo mesotelial a la cara epicárdica del parche. En los pacientes con antecedentes de revascularización miocárdica quirúrgica, la necesidad de una nueva revascularización depende de la progresión de la enfermedad aterosclerótica y de la estabilidad y la permeabilidad de los injertos. La necesidad de una reintervención aumenta progresivamente y tiene una relación directa con el tiempo transcurrido desde la operación. Se ha descrito que es necesaria una segunda revascularización miocárdica tras 5, 10, 15 y 20 años en aproximadamente un 4, un 12, un 27 y un 40% de los pacientes respectivamente. CARTAS AL EDITOR