Bernardita Garayar P

Factores determinantes en la aparición de fibrilación auricular post-cirugía de revascularización miocárdica: Un estudio prospectivo

Background: Atrial fibrillation (AF) is a relevant complication after coronary artery bypass grafting (CABG). However there is controversy regarding possible contributing factors. Aim: To study the incidence of AF, its risk factors and its repercussion on hospital stay and charges, in patients undergoing CABG. Material and methods: We prospectively collected information from all patients undergoing CABG in our institution, including demographic, surgical and laboratory variables. Exclusion criteria were chronic AF, recent onset AF and patients who needed additional surgical procedures. The primary endpoint was the incidence of AF during the hospital stay. Secondary endpoints were hospital length of stay and hospital charges. Results: We included 250 patients aged 62±9 years (199 males) in the analysis. Incidence of AF was 22% (54 patients). Multivariable analysis showed that age (Odds Ratio (OR) =1.10), previous CABG (OR =9.39), previous use of ACE inhibitors (OR =3.28) and aortic clamp >57 minutes (OR =3.97) were significantly associated with an increased risk of postoperative AF. Previous use of beta-blockers was associated with risk reduction (OR =0.43). Patients who developed AF had a longer hospital stay (p <0.001) and higher hospital charges (p =0.003). Conclusion: AF is a frequent complication in patients undergoing CABG. Risk factors are age, time of aortic clamp, previous CABG and ACE inhibitors. Beta-blockers may prevent its occurrence. Furthermore, AF has a negative impact on both hospital stay and hospital charges (Rev Med Chile 2007; 135: 967-74).

Tratamiento de la insuficiencia cardíaca avanzada mediante trasplante de corazón

Background: Heart transplantation currently provides the most effective treatment for advanced heart failure. However, medical therapy for this condition has also improved, heart donors are scarce and the cost of the procedure is high. Therefore the indications and management of these patients need reevaluation. Aim: To analyze the results of 24 patients submitted to heart transplantation for end-stage heart failure needing repeated hospitalizations and i.v. inotropes for compensation. Patients and methods: The group was comprised by 21 men and 3 women with a mean age of 36.8 years, mean left ventricular ejection fraction 19±4.5%, mean systolic pulmonary artery pressure 48±13 mmHg (24-70) and mean pulmonary vascular resistance 2.6 Wood Units (1-5). Fourteen patients (58%) had a previous median sternotomy. Immunosupression did not include induction therapy and steroids were discontinued early. Results: Operative mortality was 4% at 30 days. Actuarial survival at one year was 90% and at 5 years 72%. Freedom from rejection at one year was 76% and at 5 years 50%. Freedom from infection was 70% at one year and 56.5% at five years. All patients with more than 3 months of follow-up were in functional class I. Conclusions: These results justify the proposed modifications for transplantation protocols (Rev Med Chile 2001; 129: 9-17).

Asistencia ventricular mecánica como puente al trasplante en pacientes en shock cardiogénico: Experiencia preliminar en Chile con ABIOMED BVS 5000 ®

Hospitalization and death due to heart failure and cardiogenic shockis frequent and currently is increasing among the adult population. Although cardiac transplantationis the most effective treatment in patients with end-stage heart failure, its availability is limited. Whilewaiting for transplantation, some patients become refractory to treatment and deteriorateprogressively. Secondary multi-organ damage could highly compromise the transplant success andalso could contraindicate it. Mechanical ventricular assist devices allow reestablishing normal cardiacoutput and they have been used as a bridge to recovery and transplantation. We report four patientsthat underwent mechanical ventricular support using the ABIOMED BVS 5000Hospitalization and death due to heart failure and cardiogenic shock is frequent and currently is increasing among the adult population. Although cardiac transplantation is the most effective treatment in patients with end-stage heart failure, its availability is limited. While waiting for transplantation, some patients become refractory to treatment and deteriorate progressively. Secondary multi-organ damage could highly compromise the transplant success and also could contraindicate it. Mechanical ventricular assist devices allow reestablishing normal cardiac output and they have been used as a bridge to recovery and transplantation. We report four patients that underwent mechanical ventricular support using the ABIOMED BVS 5000 system as a bridge for transplantation. Two patients were connected to biventricular assistance; a third patient was connected to a left ventricular support and the fourth to a right ventricular support. Three were successfully transplanted and one died of refractory non-cardiogenic shock. There were no complications related to the support system, such as infection, hemorrhage or stroke. In our experience, the ABIOMED BVS 5000 was an effective strategy as a bridge to heart transplant in patients in cardiogenic shock.

Aneurisma aórtico abdominal en pacientes mayores de 80 años: tratamiento quirúrgico convencional en 80 casos consecutivos

Background: Abdominal aortic aneurysms (AAA) may be lethal unless appropriately and timely treated. Since age is a surgical risk, octogenarians are usually not considered as candidates for surgical intervention. Aim: To asses surgical complications and mortality in octogenarians treated for AAA. Subjects and Methods: Patients aged 80 years older, treated consecutively between 1984-2001 were retrospectively analyzed. Results: Sixty one patients were male, and their age ranged from 80 to 95 years. All were treated with open surgery. The operation was elective in 58 and as an emergency in 22 patients (symptomatic or ruptured AAA). Aortic diameter was 6.8±1.4 cm in asymptomatic patients and 7.7±1.8 cm in emergency cases (p=0.024). Thirty days postoperative mortality was 5.1% in elective surgery compared to 40.6% in emergency operations (p <0.01). Five years survival rate was 44.7% in asymptomatic patients compared to 10.4% in the emergency cases (p <0.023). Conclusions: Elective surgery for asymptomatic AAA can be performed with low operative mortality in octogenarians. However, surgery in emergency cases has an 8 fold increase in risk. Accordingly, octogenarian patients should be considered for elective AAA repair in a selective basis (Rev Med Chile 2003; 131: 981-6). (Key Words: Aged, 80 and over; Aneurysm, dissecting; Surgical procedures, operative)

Reemplazo parcial o total del arco aórtico: Experiencia en 23 pacientes

Between 1988 and 2002, 23 patients wereoperated. Seventeen had aortic dissection (10 acute and 7 chronic), five had an atheroscleroticaneurysm and one had a traumatic lesion. Thirteen patients were subjected to a replacement of thearch plus ascending aorta, six to a replacement of the arch plus descending aorta and four to areplacement of the arch, ascending and descending aorta. Seven patients had previous operation ofthe thoracic aorta. Arterial perfusion was done via the femoral artery, axillary artery or a combinationof both. A hypothermic circulatory arrest was induced in 22; it was associated with cerebral retroperfusion alone in 8 patients, antegrade cerebral perfusion in 5; isolated or associated axillaryperfusion was used in five patients. In seven, procedures on the aortic or mitral valve, or coronaryartery operations were added. Operative mortality was 26%, 3 of the 8 patients operated as anemergency and 3 of 15 elective operations. There was no mortality among those without dissection andof 7 chronic dissections, one died. All patients were followed for an average of 45 months. Two patientsrequired reinterventions on the aorta and one for colon cancer. There was one late death of unknowncause. Postoperative complications were agitation, bleeding and temporary vocal cord dysfunction.

Falla cardio-respiratoria severa tratada con asistencia cardiopulmonar extracorpórea: Caso clínico

Cardiopulmonary extracorporeal assistance is a high complexity procedure for patients with acute respiratory failure, who have failed conventional ventilatory support. A 30 years old female patient with bacterial endocarditis and congestive cardiac failure subjected to cardiac surgery presented severe hypoxemia, right heart failure and pulmonary hypertension, and failed conventional treatment. Cardiopulmonary support with extracorporeal membrane oxygenation (ECMO) reverted the pathophysiologic alterations allowing a successful recovery (Rev Med Chile 2002; 130: 545-50)

Reoperaciones coronarias: análisis retrospectivo de 16 años de experiencia

Background: Coronary artery bypass grafting (CABG) reoperation is being performed with increasing frequency. Aim: To assess the early and long term results of coronary reoperations in our institution and to identify prognostic factors. Patients and methods: 214 patients subjected to coronary reoperations between 1983 and 1999 were retrospectively studied. Results: Mean age was 64.2 years (range 42-79 years), 202 (94.4%) were male and 12 (5.6%) female. The mean interval between the operations was 125.7 months (range 6-252 months). 10 (4,6%) were emergency surgeries. Overall operative mortality was 5.6% (11 deaths) and in 5 patients (3.4%) a perioperative myocardial infarction was noted. Univariate analysis identified moderate or severe left ventricular failure (p=0.048) as predictor of increased operative mortality, meanwhile age over 75 years (p=0.02) and moderate or severe left ventricular failure (p=0.01) were identified as predictors of increased in hospital mortality in the multivariate analysis. Follow up of in hospital survivors (mean interval 65 months, range 4 to 190 months) documented a 5 years survival rate of 82.9%, a 10 years survival rate of 73.1% and a 15 years survival rate of 53.4%. Moderate or severe left ventricular failure (p <0.0001) and emergency surgeries (p=0.007) were identified as factors influencing the late survival in the stepwise logistical regression analysis. Multivariate analysis identified left ventricular failure (p=0.01) and peripheral vascular disease (p=0.01) as predictors of decreased late survival. Conclusions: Coronary reoperation has a low mortality in patients with a normal ventricular function and also has an excellent overall and disease free survival in the first 10 years of follow up. Left ventricular function is an independent risk factor increasing in hospital and late mortality (Rev Med Chile 2001; 129: 1131-41)

Criocoagulación de venas pulmonares como tratamiento complementario de la fibrilación auricular en cirugía valvular

Twenty onepatients had simultaneous valvular surgery and CPV, 81% of them had permanent AF for an average of5 years. Twenty patients had mitral valve disease. The etiology was rheumatic in 14. Average left atrialdiameter was 60 mm. In 7 patients the mitral valve was replaced, in 5 it was repaired, in 7 both mitraland aortic valve were replaced, in 1 the mitral valve was repaired and the aortic valve was replacedand in 1 only the aortic valve was replaced. A combined transeptal and superior approach was used forall patients. The CPV was performed after the valvular procedure with cryothermy at -60