Characterization of the impact of catheter-tissue contact force in lesion formation during cavo-tricuspid isthmus ablation in an experimental swine model.

AIMS: Catheter-tissue contact is critical for effective lesion creation. The objective of this study was to determine in an experimental swine model the pathological effects of cavo-tricuspid isthmus ablation using two systems that provide reliable measures of the pressure at the catheter tip during radiofrequency ablation procedures. METHODS AND RESULTS: We performed the procedure in eight pigs in our experimental electrophysiology laboratory after right femoral vein dissection and insertion of a 12 Fr. introducer during general anaesthesia and endotracheal intubation. The target contact force during the applications was <10 grs. (axial or lateral), 10-20, 20-30, and >30 grs. in two pigs each. The power was set at 40 W and maximum target temperature at 45°C. We performed a radiofrequency line dragging from the tricuspid valve to the inferior vena cava in the eight pigs. Euthanasia of the animals was carried out a week after the procedure and a pathological examination of the lesions was performed. In the endocardial macroscopic analysis the extent of lesions, presence of thrombus, transmurality, and endothelial rupture was assessed. External surface was examined searching for transmural lesions. The mean contact force applied was 18.7 ± 8.4 grs. and the mean depth of the lesions was 3.6 ± 2 mm. Lesions were never transmural with average forces <10 grs., and the mean depth was very low (0.75 mm). To achieve transmural lesions contact forces of at least 20 grs. were required. We found a positive correlation (r = 0.85, P < 0.05) between the average force during the applications and depth of the lesions. CONCLUSION: When ablating the cavo-tricuspid isthmus in a swine model, contact forces of at least 20 grs. are required to achieve transmural lesions. Catheter-tissue contact is critical for effective lesion creation. This information is important for improving ablation efficacy.

Evolution of differentiated thyroid cancer during pregnancy in a community University Hospital in Buenos Aires, Argentina.

OBJECTIVE: To analyze the presentation, follow-up and evolution of differentiated thyroid cancer (DTC) detected during pregnancy. SUBJECTS AND METHODS: Twenty nine women with DTC detected during pregnancy were analyzed. Group I (n = 13) was seen during pregnancy and DTC was diagnosed during gestation; detection of the nodule occurred during pregnancy (first trimester). Group II (n = 16) was seen after delivery; detection of the nodule occurred during pregnancy (second or third trimester). Complete thyroidectomy, ablative dose of radioactive iodine, and treatment with levothyroxine were performed. FOLLOW-UP: neck ultrasound; TSH, free T4, thyroglobulin, and anti-thyroglobulin antibodies with and without treatment with levothyroxine; and 131I whole body scans. Histological diagnosis, lymph node metastases, tumor size and stage, complications from pregnancy, and DTC evolution were evaluated. RESULTS: 100% of the patients had papillary thyroid carcinoma. Lymph node metastases were detected in 13 (44.8%), and invasion of adjacent extrathyroid tissue in 2 patients. Tumor size was larger in Group II: 22.1 ± 10.9 versus 13.9 ± 3.5 mm; p = 0.03. No differences were found in the tumor stages between groups. All patients had full-term pregnancies and healthy newborns. FOLLOW-UP: 5.7 ± 4.3 years; one patient had persistent disease. CONCLUSIONS: DTC detected during pregnancy had a favorable evolution. Surgery may be postponed to the post-delivery period, unless there are risk factors that justify it during pregnancy.

Asociación de valores de proteína C reactiva preoperatoria con complicaciones en el posoperatorio de cirugía cardiovascular / Association between Preoperative C-Reactive Protein Levéis with Postoperative Complications of Cardiovascular Surgery

Introducción El síndrome de respuesta inflamatoria sistémica es una complicación frecuente en el posoperatorio de cirugía cardíaca, que puede evolucionar con shock vasopléjico y los casos más graves pueden derivar en falla de uno o más órganos. Se describieron predictores en el preoperatorio y el perioperatorio asociados con esta complicación; sin embargo, un estado de inflamación subclínico en la etapa preoperatoria, no detectado por estudios de rutina, podría relacionarse con la respuesta inflamatoria desencadenada en el posoperatorio. Niveles elevados de proteína C reactiva (PCR), un parámetro de inflamación en diferentes escenarios clínicos y que se asocia con el pronóstico de diversas patologías cardiovasculares, podrían predecir el síndrome. Objetivo Evaluar la contribución de la elevación de los niveles preoperatorios de proteína C reactiva para predecir el síndrome de respuesta inflamatoria sistémica y sus complicaciones posoperatorias en cirugía cardíaca. Material y métodos Se incluyeron 169 pacientes consecutivos, prospectivos (77,3% hombres, edad 61,1 ± 15,9, Euroscore 9,46 [DE 12,7]) sometidos a cirugía cardíaca entre abril de 2007 y diciembre de 2008. Se determinó el nivel de PCR en todos los pacientes. El punto final combinado incluyó síndrome de respuesta inflamatoria sistémica y su asociación con fibrilación auricular, insuficiencia renal, shock o muerte. Resultados Ochenta y siete pacientes (54%) desarrollaron el síndrome de respuesta inflamatoria sistémica y 50 pacientes (31%) presentaron el punto final combinado. La mortalidad intrahospitalaria fue del 5,6% (9 pacientes). Ajustados por variables preoperatorias e intraoperatorias, los niveles preoperatorios de PCR ≥ 2 mg/dl se asociaron independientemente con el punto final combinado (OR 2,95, IC 95% 1,20-7,23; p < 0,018), con la evolución con síndrome de respuesta inflamatoria sistémica (SRIS) (OR 2,46, IC 95% 1,17-5,15; p < 0,000), SRIS combinado con insuficiencia renal (OR 5,10, IC 95% 1,48-17,58; p < 0,010), SRIS combinado con shock (OR 6,50, IC 95% 1,59-27,34; p < 0,005), SRIS combinado con fibrilación auricular (OR 3,51, IC 95% 1,14-10,79; p < 0,028), insuficiencia renal (OR 2,91, IC 95% 1,19-7,12; p < 0,019) y shock (OR 4,13, IC 95% 1,25-13,60; p < 0,020). Conclusiones Los niveles preoperatorios de PCR ≥ 2,0 mg/dl pueden predecir el síndrome de respuesta inflamatoria sistémica y el síndrome de respuesta inflamatoria sistémica con insuficiencia renal, fibrilación auricular, shock y muerte en el posoperatorio de cirugía cardíaca.

Background Systemic inflammatory response syndrome is a frequent postoperative complication of cardiovascular surgery that can develop vasoplegic shock and organ or multiorgan dysfunction in tlie most severe cases. Preoperative and postoperative predictors associated with this complication have been described; however, a subclinical preoperative inflammatory state, not detected by routine tests, might be related to the postoperative inflammatory response. Elevated C-reactive protein (CRP) levéis, a parameter of inflammation in different clinical scenarios that is associated with the prognosis of diverse cardiovascular diseases, might predict the syndrome. Objective To evalúate the valué of elevated C-reactive protein to predict systemic inflammatory response syndrome and its postoperative complications after cardiovascular surgery. Material and Methods A total of 169 consecutive patients (77.3% were men, age 61.1±15.9, Euroscore 9.46 [SD 12.7]) undergoing cardiovascular surgery were prospectively included between April 2007 and December 2008. CRP levéis were determined in all patients. The combined endpoint included the incidence of systemic inflammatory response syndrome and its association with atrial fibrillation, kidney failure, shock or death. Results Eighty seven patients (54%) developed systemic inflammatory response syndrome and 50 patients (31%) presented the combined endpoint. In-hospital mortality was 5.6% (9 patients). The preoperative levéis of CRP >2 mg/dl adjusted for preoperative and postoperative variables were independently associated with the combined endpoint (OR 2.95, 95% CI 1.20-7.23; p<0.018), with the development of systemic inflammatory response syndrome (SIRS) (OR 2.46, 95% CI 1.17-5.15; p<0.000), and with the combination of SIRS and kidney failure (OR 5.10, 95% CI 1.48-17.58; p<0.010), SIRS and shock (OR 6.50, 95% CI 1.59-27.34; p<0.005), and SIRS and atrial fibrillation (OR 3.51, 95% CI 1.14-10.79; p<0.028), kidney failure (OR 2.91, 95% CI 1.19-7.12; p<0.019) and shock (OR 4.13, 95% CI 1.25-13.60; p < 0.020). Conclusions Preoperative levéis of CRP >2.0 mg/dl may predict the systemic inflammatory response syndrome and the systemic inflammatory response syndrome with kidney failure, atrial fibrillation, shock and death in the postoperative period of cardiovascular surgery.

Realidad de la cirugía cardíaca en la República Argentina: Registro CONAREC XVI / Real Facts in Cardiovascular Surgery in Argentina. The XVI CONAREC Registry

Introducción Los dos grandes registros multicéntricos de cirugía cardíaca realizados en la Argentina, CONAREC y ESMUCICA, datan de más de 10 años. Considerando los avances médicos y quirúrgicos de la última década, surgió la necesidad de realizar un nuevo registro nacional, prospectivo y multicéntrico para conocer las características, la evolución, las complicaciones y los predictores de mortalidad de los pacientes sometidos a cirugía cardíaca. Objetivos Conocer el perfil epidemiológico, la modalidad quirúrgica y la evolución posoperatoria de los pacientes sometidos a cirugía cardíaca en la Argentina. Material y métodos Registro prospectivo, consecutivo y multicéntrico realizado en 49 centros cardioquirúrgicos de la República Argentina por residentes de cardiología. Se analizaron las características y la evolución de 2.553 pacientes sometidos a cirugía cardíaca entre septiembre de 2007 y octubre de 2008: 1.465 (57,4%) a cirugía coronaria, 359 (14,1%) a reemplazo valvular aórtico, 169 (6,6%) a cirugía valvular mitral, 312 (12,2%) a cirugía combinada coronariovalvular y 248 (9,7%) a otros procedimientos. Resultados Hubo predominio de hombres (74,9%); la edad promedio fue de 63 ± 11 años. La prevalencia de diabetes fue del 24,9%, la de hipertensión del 76,3% y la de insuficiencia cardíaca del 17%. La disfunción ventricular moderada a grave prequirúrgica fue del 23,8% y el 19,8% de las cirugías fueron no programadas. En las cirugías coronarias, el 41,9% de ellas se realizaron sin circulación extracorpórea y se empleó puente mamario en el 89%. El 81,7% de las cirugías mitrales se indicaron por insuficiencia y el 62,6% de las aórticas, por estenosis. En estas cirugías se emplearon válvulas mecánicas en el 58% de los casos. La mediana de internación fue de 6 días. Se presentaron complicaciones mayores en el 31,7% (del 25% en coronarios al 49,36% en combinados) y la mortalidad global fue del 7,7% (del 4,3% en coronarios al 13,4% en combinados). Conclusiones Este registro muestra la realidad de la cirugía cardíaca en centros con residencia o concurrencia de cardiología. Comparadas con cifras de registros nacionales previos, la mortalidad y las complicaciones mayores han disminuido, pero continúan siendo elevadas.

Background The CONAREC and the ESMUCICA studies are the largest multicenter registries performed in Argentina more than 10 years ago. The clinical and surgical advances achieved during the last decade have obliged us to carry out a new national, prospective and multicenter registry to become aware of the characteristics, outcomes, complications and predictors of mortality of patients undergoing cardiac surgery. Objectives To recognize the epidemiologic profile, surgical approach and postoperative outcomes of patients undergoing cardiac surgery in Argentina. Material and Methods This is a prospective, consecutive and multicenter registry performed by residents in Cardiology in 49 centers with cardiovascular surgery facilities. A total of 2553 patients undergoing cardiac surgery were included between September 2007 and October 2008, distributed as follows: coronary artery bypass graft surgery, 1465 patients (57.4%); aortic valve replacement, 359 (14.1%); mitral valve surgery, 169 (6.6%); combined procedure (revascularization-valve surgery), 312 (12.2%); other procedures, 248 (9.7%). Results There were more men (74.9%) than women; mean age was 63±11 years. The prevalence of diabetes was 24.9%, of hypertension 76.3% and of heart failure 17%. Preoperative moderate to severe left ventricular dysfunction was 23.8%, and 19.8% of surgeries were done on an urgent or emergency basis. A 41.9% of coronary artery bypass graft surgeries were done without cardiopulmonary bypass and a mammary artery bypass graft was used in 89%. Mitral valve surgery was indicated due to mitral regurgitation in 81.7% of cases and 63.6% of aortic valve surgeries were due to aortic valve stenosis. Mechanical heart valve prostheses were used in 58% of cases. Patients were hospitalized for a median of 6 days. Major complications occurred in 31.7% of cases (25% in revascularization surgeries and 49.36% in combined procedures) and global mortality was 7.7% (4.3% and 49.36%, respectively). Conclusions This registry demonstrates the real facts in cardiovascular surgery in centers with cardiovascular residents in Cardiology. Mortality and major complications are lower than those reported by previous registers, yet they are still high.