Elevated pre-operative serum peptides for collagen I and III synthesis result in post-surgical atrial fibrillation.

OBJECTIVES: This study sought to determine if serum markers for collagen I and III synthesis, the carboxyl terminal peptide from pro-collagen I (PICP) and the amino terminal peptide from pro-collagen III (PIIINP), correlate with left atrial (LA) fibrosis and post-operative atrial fibrillation (AF). BACKGROUND: AF after cardiac surgery is associated with adverse outcomes. We recently demonstrated that LA fibrosis is associated with post-operative AF in patients with no previous history of AF. METHODS: Fifty-four patients having cardiac surgery without a history of AF consented to left and right atrial biopsies and a pre-operative peripheral blood draw. Picrosirius red staining quantified the percentage of fibrosis, and reverse transcriptase polymerase chain reaction assessed atrial tissue messenger ribonucleic acid transcripts involved in the fibrosis pathway. PICP and PIIINP levels were measured using an enzyme immunosorbent assay. RESULTS: Eighteen patients developed AF, whereas 36 remained in normal sinus rhythm. LA fibrosis was higher in patients who developed AF versus normal sinus rhythm (6.13 ± 2.9% vs. 2.03 ± 1.9%, p = 0.03). LA messenger ribonucleic acid transcripts for collagen I, III, transforming growth factor, and angiotensin were 1.5- to 2.0-fold higher in AF patients. Serum PICP and PIIINP levels were highest in AF versus normal sinus rhythm (PICP: 451.7 ± 200 ng/ml vs. 293.3 ± 114 ng/ml, p = 0.006; PIIINP: 379 ± 286 pg/ml vs. 191.6 ± 162 pg/ml, p = 0.01). Furthermore, there was a linear correlation between LA fibrosis and serum PICP levels (R(2) = 0.2; p = 0.01), and of the markers, only PICP was independently associated with AF. CONCLUSIONS: This demonstrates that serum PICP and PIIINP levels correlate with the presence of LA fibrosis and may act as predictors for post-operative AF even in the absence of previous history of AF.

Cerebral oximetry during cardiac surgery: the association between cerebral oxygen saturation and perioperative patient variables.

OBJECTIVE: This "real-world" study was designed to assess the patterns of regional cerebral oxygen saturation (rSO(2)) change during adult cardiac surgery. A secondary objective was to determine any relation between perioperative rSO(2) (baseline and during surgery) and patient characteristics or intraoperative variables. DESIGN: Prospective, observational, multicenter, nonrandomized clinical study. SETTING: Cardiac operating rooms at 3 academic medical centers. PARTICIPANTS: Ninety consecutive adult patients presenting for cardiac surgery with or without cardiopulmonary bypass. INTERVENTIONS: Patients received standard care at each institution plus bilateral forehead recordings of cerebral oxygen saturation with the 7600 Regional Oximeter System (Nonin Medical, Plymouth, MN). MEASUREMENTS AND MAIN RESULTS: The average baseline (before induction) rSO(2) was 63.9 ± 8.8% (range 41%-95%); preoperative hematocrit correlated with baseline rSO(2) (0.48% increase for each 1% increase in hematocrit, p = 0.008). The average nadir (lowest recorded rSO(2) for any given patient) was 54.9 ± 6.6% and was correlated with on-pump surgery, baseline rSO(2), and height. Baseline rSO(2) was found to be an independent predictor of length of stay (hazard ratio 1.044, confidence interval 1.02-1.07, for each percentage of baseline rSO(2)). CONCLUSIONS: In cardiac surgical patients, lower baseline rSO(2) value, on-pump surgery, and height were significant predictors of nadir rSO(2), whereas only baseline rSO(2) was a predictor of postoperative length of stay. These findings support previous research on the predictive value of baseline rSO(2) on length of stay and emphasize the need for further research regarding the clinical relevance of baseline rSO(2) and intraoperative changes.

Meta-analysis of average and variability of time to extubation comparing isoflurane with desflurane or isoflurane with sevoflurane.

BACKGROUND: We recently determined how to use anesthesia information management system data to model the time from end of surgery to extubation. We applied that knowledge for meta-analyses of trials comparing extubation times after maintenance with desflurane and sevoflurane. In this study, we repeated the meta-analyses to compare isoflurane with desflurane and sevoflurane. METHODS: A Medline search through December 2009 was used to identify studies with (1) humans randomly assigned to isoflurane or desflurane groups without other differences (e.g., induction drugs) between groups, and (2) mean and SD reported for extubation time and/or time to follow commands. The search was repeated for random assignment to isoflurane or sevoflurane groups. We considered extubation times >15 minutes (representing 15% of cases in the anesthesia information management system data) to be prolonged. RESULTS: Desflurane reduced the mean extubation time by 34% and reduced the variability in extubation time by 36% relative to isoflurane. These reductions would reduce the incidence of prolonged extubation times by 95% and 97%, respectively. Sevoflurane reduced the mean extubation time by 13% and reduced the SD by 8.7% relative to isoflurane. These reductions would reduce the incidence of prolonged extubation times by 51% and 35%, respectively. CONCLUSIONS: The pharmacoeconomics of volatile anesthetics are highly sensitive to measurement of relatively small time differences. Therefore, surgical facilities should use these values combined with their local data (e.g., mean baseline extubation times) when making evidence-based management decisions regarding pharmaceutical purchases and usage guidelines.

Robot-assisted mitral valve repair: a single institution review.

OBJECTIVE: Mitral valve repair (MVR) is the definitive therapy for mitral myxomatous degeneration. Median sternotomy has been the traditional approach to repair until the advent of the da Vinci Surgical System (Intuitive Surgical, Inc., Sunnyvale, CA). Minimally invasive surgical approaches for mitral repair have been slow to gain acceptance in cardiac surgery. We review the MVR results from our single-institution academic robotic program. METHODS: From August 2004 through April 2008, patients who underwent a robotic-assisted (RA) MVR were identified. RA technique included a 4-cm right minithoracotomy, femoral cardiopulmonary bypass with transthoracic aortic occlusion, and RA-MVR. Repair types were combinations of quadrangular/triangular leaflet resection, sliding plasty, chordal transfer/replacement, and edge-to-edge approximation, with band annuloplasty in all cases. Postrepair echocardiography and morbidity follow-ups were completed in all patients. Our primary outcome was adequacy of repair, and secondary outcome was major complications. RESULTS: There were 43 patients (29 male and 14 female) who underwent RA-MVR for severe (4+) mitral regurgitation during the 4-year review. Average operative time was 272.26 minutes. Only one patient had mild postoperative mitral regurgitation, whereas 20 had trace and 22 had no regurgitation after repair. Mean ventilator time was 32.1 hours, and length of stay was 5.7 days. One third of the patients (33%) received postoperative-packed red blood cell transfusions (average: 2.4 units per patient). Twenty-eight percent of patients developed atrial fibrillation after repair. Most of the patients (95.3%) were discharged home. There were no 30-day mortalities. CONCLUSIONS: Based on our small single-institution experience, RA-MVR provides an effective treatment for severe mitral valve regurgitation. Although procedure durability is slowly being established, preliminary results are promising. Careful programmatic advances with an integrated team approach can facilitate acceptable postoperative outcomes and excellent MVR.