Simplified clinical risk score to predict acute kidney injury after aortic surgery.

OBJECTIVE: The authors identified risk factors for acute kidney injury (AKI) defined by risk, injury, failure, loss, end-stage (RIFLE) criteria after aortic surgery with cardiopulmonary bypass and constructed a simplified risk score for the prediction of AKI. DESIGN: Retrospective and observational. SETTING: Single large university hospital. PARTICIPANTS: Patients (737) who underwent aortic surgery with cardiopulmonary bypass between 1997 and 2010. MAIN RESULTS: Multivariate logistic regression analysis was used to evaluate risk factors. A scoring model was developed in a randomly selected derivation cohort (n = 417), and was validated on the remaining patients. The scoring model was developed with a score based on regression ß-coefficient, and was compared with previous indices as measured by the area under the receiver operating characteristic curve (AUC). The incidence of AKI was 29.0%, and 5.8% required renal replacement therapy. Independent risk factors for AKI were age older than 60 years, preoperative glomerular filtration rate <60 mL/min/1.73 m(2), left ventricular ejection fraction <55%, operation time >7 hours, intraoperative urine output <0.5 mL/kg/h, and intraoperative furosemide use. The authors made a score by weighting them at 1 point each. The risk score was valid in predicting AKI, and the AUC was 0.74 [95% confidence interval (CI): 0.69 to 0.79], which was similar to that in the validation cohort: 0.74 (95% CI: 0.69 to 0.80; p = 0.97). The risk-scoring model showed a better performance compared with previously reported indices. CONCLUSIONS: The model would provide a simplified clinical score stratifying the risk of postoperative AKI in patients undergoing aortic surgery.

Positive correlation between the dysregulation of transforming growth factor-ß1 and aneurysmal pathological changes in patients with Marfan syndrome.

BACKGROUND: Our goal was to investigate the correlation between the dysregulation of transforming growth factor-ß1 (TGF-ß1) and cystic medial degeneration in the aortic aneurysmal tissues of in Marfan syndrome (MFS) patients. Although aortic aneurysm in animal models of MFS is related to the dysregulation of TGF-ß, it has yet to be determined whether TGF-ß dysregulation correlates with pathogenic aneurysmal characteristics in MFS patients. METHODS AND RESULTS: Compared with aortic tissue from normal individuals, the medial layers of aortic tissue from MFS patients exhibited profound cystic medial degeneration and cellular apoptosis. These histopathologic changes positively correlated with the extent of TGF-ß1 signaling activation (Smad2 phosphorylation) in aneurysmal aortic tissue. In addition, the level of TGF-ß1 expression in peripheral blood and aneurysmal aortic tissues was significantly elevated in MFS patients. A significant positive correlation was observed between the plasma level of active TGF-ß1 in MFS patients and the severity of cystic medial degeneration and Smad2 phosphorylation in aneurysmal aortic medial layers. CONCLUSIONS: We found a strong association between the dysregulation of TGF-ß1 and aortic pathogenesis in human MFS patients. This suggests that the plasma concentration of TGF-ß1 in MFS patients might be a useful biomarker of the progression of aortic aneurysms.

Surgical experience of ascending aorta and aortic valve replacement in patient with calcified aorta.

BACKGROUND: The conventional method of aortic cross-clamping is very difficult and increases the risk of cerebral infarct due to embolism of the calcified aorta in these patients. Accordingly, we analyzed our experience with 11 cases of ascending aorta and aortic valve replacement with hypothermic circulatory arrest. MATERIALS AND METHODS: From January 2002 to December 2009, 11 patients had ascending aorta and aortic valve replacement with hypothermic arrest at our hospital. We performed a retrospective study. RESULTS: There were 5 males and 6 females, with a mean age of 68 years (range, 44 to 82 years). Eight patients had aortic stenosis, and 3 patients had aortic regurgitation. An aortic cannula was inserted into the right axillary artery in 3 patients and ascending aorta in 6 patients. Two patients with aortic regurgitation had a remote access perfusion catheter inserted though the right femoral artery. The mean cardiopulmonary bypass time was 180 minutes (range, 110 to 306 minutes) and mean hypothermic circulatory arrest time was 30 minutes (range, 20 to 48 minutes). The mean rectal temperature during hypothermic circulatory arrest was 21℃ (range, 19℃ to 23℃). No patient had any new onset of cerebral infarct or cardiovascular accident after surgery. There was no hospital mortality. Early complications occurred in 1 patient who needed reoperation due to postoperative bleeding. Late complications occurred in 1 patient who underwent a Bentall operation due to prosthetic valve endocarditis. The mean follow-up duration was 32 months (range, 1 month to 8 years) and 1 patient died suddenly due to unknown causes after 5 years. CONCLUSION: Patients with a calcified aorta can be safely treated with a technique based on aorta and aortic valve replacement under hypothermic circulatory arrest.

Mass reduction and functional improvement of the left ventricle after aortic valve replacement for degenerative aortic stenosis.

BACKGROUND: Left ventricular (LV) hypertrophy caused by aortic valve stenosis (AS) leads to cardiovascular morbidity and mortality. We sought to determine whether aortic valve replacement (AVR) decreases LV mass and improves LV function. MATERIALS AND METHODS: Retrospective review for 358 consecutive patients, who underwent aortic valve replacement for degenerative AS between January 1995 and December 2008, was performed. There were 230 men and 128 women, and their age at operation was 63.2±10 years (30~85 years). RESULTS: There was no in-hospital mortality, and mean follow-up duration after discharge was 48.9 months (2~167 months). Immediate postoperative echocardiography revealed that LV mass index and mean gradient across the aortic valve decreased significantly (p<0.001), and LV mass continued to decrease during the follow-up period (p<0.001). LV ejection fraction (EF) temporarily decreased postoperatively (p<0.001), but LV function recovered immediately and continued to improve with a significant difference between preoperative and postoperative EF (p<0.001). There were 15 late deaths during the follow-up period, and overall survival at 5 and 10 years were 94% and 90%, respectively. On multivariable analysis, age at operation (p=0.008), concomitant coronary bypass surgery (p<0.003), lower preoperative LVEF (<40%) (p=0.0018), and higher EUROScore (>7) (p=0.045) were risk factors for late death. CONCLUSION: After AVR for degenerative AS, reduction of left ventricular mass and improvement of left ventricular function continue late after operation.

Atrioventricular reverse remodeling after valve repair for chronic severe mitral regurgitation: 1-year follow-up.

BACKGROUND: Chronic severe mitral regurgitation is associated with poor clinical outcome because chronic volume overload leads to hemodynamic changes and left ventricular and left atrial remodeling. Few data are available regarding left atrial volume index regression (LAVIR) and left ventricular mass index regression (LVMIR) after valve surgery for mitral regurgitation. We aimed to identify predictive correlates of LAVIR and LVMIR and to assess the relationship between these regressions. HYPOTHESIS: Volume overload in chronic severe mitral regurgitation may influence left atrial and ventricular remodeling and reverse remodeling. METHODS: Eighty-five patients who underwent valve repair for severe chronic mitral regurgitation were consecutively enrolled. Plasma N-terminal fragment of the prohormone brain natriuretic peptide (NT-proBNP) and echocardiographic measurements were performed before surgery, before discharge, and at 12 months after surgery. LAVIR and LVMIR were assessed using serial echocardiography. RESULTS: There were significant decreases in left ventricular mass index (LVMI; from 125.9 ± 31.3 g/m² to 94.8 ± 28.6 g/m², P = 0.001) and left atrial volume index (LAVI; from 75.3 ± 33.5 mL/m² to 41.7 ± 16.0 mL/m², P = 0.001) after surgery. Preoperative LAVI positively correlated with preoperative LVMI (r = 0.437, P = 0.001) and LAVIR positively correlated with LVMIR (r = 0.347, P = 0.001). In multivariate stepwise linear regression analysis, preoperative LAVI, age, hypertension, and atrial fibrillation were independently predictive of LAVIR, and preoperative LVMI, hypertension, and NT-proBNP were independently predictive of LVMIR. CONCLUSIONS: Volume overload in chronic severe mitral regurgitation may influence left ventricular remodeling and reverse remodeling, as well as left atrial remodeling and reverse remodeling. Preoperative lower LAVI, younger age, absence of hypertension, and absence of atrial fibrillation may predict LAVIR, and preoperative lower LVMI, lower NT-proBNP levels, and absence of hypertension may predict LVMIR after surgery for chronic severe mitral regurgitation.

Preoperative N-terminal pro-B type natriuretic peptide level can predict the regression of left ventricular mass after valvular surgery in patients with chronic severe mitral regurgitation: one-year follow-up.

BACKGROUND: The aim of this study was to investigate preoperative clinical and echocardiographic characteristics and N-terminal pro-B type natriuretic peptide (NT-proBNP) levels as prognostic factors for regression of the left ventricular (LV) mass after valvular surgery in patients with chronic severe mitral regurgitation (MR). METHODS: One hundred seventeen patients undergoing surgery for chronic severe MR were included. Plasma NT-proBNP measurements and echocardiography were performed preoperatively, immediately postoperatively, and at six and 12 months after surgery. Any regression of the LV mass was evaluated by echocardiography. RESULTS: During follow-up, 90 patients (77%) were classified as an LV mass regression group (LVMR), defined as having a postoperative reduction in LV mass indexed against body surface area (LVMI). The remaining 27 (23%) patients were classified as NON-LVMR. The LVMR group was younger (p=0.029) and had significantly lower ratios of patients with hypertension (p=0.045) and diuretic use (p=0.005) than the NON-LVMR group. They also had lower levels of NT-proBNP (median: 446.4 pg/ml versus 1394.0 pg/ml, p=0.001). In multivariate analysis, higher preoperative NT-proBNP levels were independent predictors of no significant regression of the LV mass (odds ratio=1.731, 95% confidence intervals 1.052-2.844, p=0.010). CONCLUSIONS: A lower preoperative NT-proBNP level predicted the regression of LV mass after valvular surgery in patients with chronic severe MR. This measure could be used as a biomarker for predicting the postoperative course in such patients.

Preoperative, postoperative and one-year follow-up of N-terminal pro-B-type natriuretic peptide levels in volume overload of aortic regurgitation: comparison with pressure overload of aortic stenosis.

OBJECTIVES: Limited data are available regarding the impact of pressure or volume overload on the clinical or echocardiographic parameters and the levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with chronic severe aortic valve diseases. We aimed to investigate and compare the relationships between these parameters in such patients. METHODS: One hundred twenty-four consecutive patients who underwent aortic valve replacement for chronic severe aortic valve diseases were enrolled. Plasma NT- proBNP was measured and echocardiographic parameters were recorded before surgery, before discharge and 12 months after surgery. RESULTS: NT-proBNP levels were significantly higher in patients with aortic regurgitation (AR) (n = 63) than in those with aortic stenosis (n = 61) (1,836.0 ± 376.1 vs. 508.4 ± 74.5 pg/ml, p = 0.001). There was a significant relationship between NT-proBNP levels and left ventricular mass index (LVMI) in AR (r = 0.436, p = 0.002) and a weaker, but significant, relationship between NT-proBNP levels and LVMI in aortic stenosis patients (r = 0.290, p = 0.046). In the AR group, preoperative NT-proBNP levels positively correlated with LVMI regression during the 12 months after surgery (r = 0.488, p = 0.001). CONCLUSION: NT-proBNP levels may reflect LVMI changes that are caused by volume overload rather than pressure overload in chronic aortic valve diseases. Higher preoperative NT-proBNP levels may predict left ventricular reverse remodeling early after surgery for chronic severe AR.