Influence of preoperative and intraoperative factors on recovery after aortic root surgery

OBJECTIVE

To determine the influence of intraoperative factors relative to preoperative risk factors on recovery after aortic root replacement (ARR).

METHODS

Retrospective review of baseline and intraoperative characteristics was performed of 822 patients at our Aortic Center from 2005 to 2019. Inclusion criteria were all patients age 18 and older who underwent ARR at our institution from 2005 to 2019. The primary endpoint was the aggregate outcome of "failure to achieve uneventful recovery (FUR)," as previously defined.

RESULTS

In total, 207 (25%) patients experienced FUR. The following preoperative and intraoperative variables were significantly associated with FUR in the multivariable analysis: cardiopulmonary bypass time (OR 1.01, 95% CI 1.01-1.02) open chest management (OR 5.67, 95% CI 2.65-12.1), ejection fraction (OR 1.03, 95% CI 1.01-1.04), chronic kidney disease > stage 3a (OR 2.37, 95% CI 1.54-3.63), bicuspid aortic valve (OR 1.54, 95% CI 1.21-1.96), and female sex (OR 1.30, 95% CI 1.06-1.61). Cardiopulmonary bypass time and open chest management were among the top three partial R2 contributors to the logistic regression model variance.

CONCLUSIONS

These findings suggest efficacy in using intraoperative parameters to predict postoperative outcomes after ARR.

True redo-aortic root replacement versus root replacement after any previous surgery

Objective

The impact of previous aortic root replacement (True-Redo) versus any previous operation (Any-Redo) on outcomes after reoperative aortic root replacement (redo-ROOT) is largely unknown. In this first multi-institutional study, the clinical impact True-Redo versus Any-Redo in the setting of redo-ROOT was reviewed.

Methods

From 2004 to 2021, 822 patients underwent redo-ROOT at 2 major academic centers: 638 Any-Redo and 184 True-Redo. Matching based on preoperative demographics and concomitant operations resulted in 174 matched pairs. An independent risk factor analysis was performed to determine risk factors for early and late mortality.

Results

Patients in the True-Redo group were younger, at 49.9 ± 15.1 versus 55.3 ± 14.7 years, P < .001. Concomitant operations were largely similar between the 2 groups, P > .05. Median cardiopulmonary bypass time (P < .001) and aortic crossclamp time (P = .03) were longer for True-Redo group. In-hospital mortality was 13% (109) and was without significant difference between groups, P = .41. Ten-year survival was 78% versus 76% for True-Redo versus Any-Redo groups respectively, P = .7. Landmark survival analysis at 4 years' postoperatively on the matched groups found that patients in the True-Redo group had improved survival outcomes (P = .046). Risk factors of in-hospital mortality consisted of older age (P < .0001), lower ejection fraction (P = .02), and male patient (P = .0003).

Conclusions

Clinical outcomes following redo-ROOT are excellent. Performance of a True-Redo-ROOT does not result in worse in-hospital morbidity or mortality and has improved survival benefit at midterm follow-up when compared with patients in the Any-Redo group. The decision to perform a redo-ROOT must be taken seriously and must be individualized in a patient-specific manner for optimal outcomes.

Quantifying the effects of circulatory arrest on acute kidney injury in aortic surgery

OBJECTIVES

We aim to investigate the association between parameters surrounding circulatory arrest and postoperative acute kidney injury in aortic surgery.

METHODS

This is a single-center retrospective study of 1118 adult patients who underwent aortic repair with median sternotomy between January 2010 and May 2019. Acute kidney injury was defined on the basis of a modified version of the 2012 Kidney Disease Improving Global Outcomes Scale that excluded urine output. The primary outcome of interest was any stage of acute kidney injury.

RESULTS

Circulatory arrest was required in 369 patients, and 307 patients (27.5%) developed acute kidney injury: stage 1 in 241 patients, stage 2 in 38 patients, and stage 3 in 28 patients. Lower-body ischemia (the period during circulatory arrest without blood flow to kidneys) duration was not associated with acute kidney injury after multivariable logistic regression (1-40 minutes, odds ratio, 0.67; 95% confidence interval, 0.43-1.04; P = .075; >40 minutes, odds ratio, 0.67; 95% confidence interval, 0.29-1.55; P = .356). Hypertension (odds ratio, 1.65; 95% confidence interval, 1.09-2.54; P = .020), preoperative estimated glomerular filtration rate (odds ratio, 0.99; 95% confidence interval, 0.98-1.00; P = .010), packed red blood cell transfusion volume (odds ratio, 1.00; 95% confidence interval, 1.00-1.00; P = .028), and nadir temperature (odds ratio, 0.93; 95% confidence interval, 0.88-0.99; P = .013) were independently associated with acute kidney injury after multivariable analysis. Although there was a positive association between lower-body ischemia duration and development of acute kidney injury with univariable cubic spline, the positive curve was flattened after adjustment for the described variables.

CONCLUSIONS

Within the range of our clinical practice, prolonged lower-body ischemia duration was not independently associated with postoperative acute kidney injury, whereas nadir temperature was.

Extent of aortic replacement and operative outcome in open proximal thoracic aortic aneurysm repair

Objectives

There are few data to delineate the risk differences among open aortic procedures. We aimed to investigate the influence of the procedural types on the outcomes of proximal thoracic aortic aneurysm repair.

Methods

Among 1900 patients who underwent aortic replacement in our institution between 2005 and 2019, 1132 patients with aortic aneurysm who underwent a graft replacement of proximal thoracic aorta were retrospectively reviewed. Patients were divided into 4 groups based on the extent of the aortic replacement: isolated ascending aortic replacement (n = 52); ascending aortic replacement with distal extension with hemiarch, partial arch, or total arch replacement (n = 126); ascending aortic replacement with proximal extension with aortic valve or root replacement (n = 620); and ascending aortic replacement with distal and proximal extension (n = 334). "Eventful recovery," defined as occurrence of any key complications, was used as the primary end point. Odds ratios for inability to achieve uneventful recovery in each procedure were calculated using ascending aortic replacement as a reference.

Results

Overall, in-hospital mortality and stroke occurred in 16 patients (1.4%) and 24 patients (2.1%). Eventful recovery was observed in 19.7% of patients: 11.5% in those with ascending aortic replacement, 36.5% in those with partial arch or total arch replacement, 16.6% in those with proximal extension with aortic valve or root replacement, and 20.4% in those with distal and proximal extension (P < .001). With ascending aortic replacement as the reference, a multivariable logistic regression revealed partial arch or total arch replacement (odds ratio, 10.0; 95% confidence interval, 1.8-189.5) was an independent risk factor of inability to achieve uneventful recovery.

Conclusions

Open proximal aneurysm repair in the contemporary era resulted in satisfactory in-hospital outcomes. Distal extension was associated with a higher risk for postoperative complications.

Long-term outcome of hemiarch replacement in a proximal aortic aneurysm repair: analysis of over 1000 patients

OBJECTIVES

The aim of this study was to investigate the impact of hemiarch replacement in patients undergoing an open repair of proximal thoracic aortic aneurysm without arch aneurysm.

METHODS

A retrospective review was performed on 1132 patients undergoing proximal aortic aneurysm repair at our Aortic Center between 2005 and 2019. Inclusion criteria were all patients undergoing root or ascending aortic aneurysm repair with or without hemiarch replacement. Exclusion criteria were age <18 years, aortic arch diameter ≥4.5 cm, type A aortic dissection, previous ascending aortic replacement, ruptured aneurysm and endocarditis. Propensity score matching in a 2:1 ratio (573 non-hemiarch: 288 hemiarch) on 19 baseline characteristics was performed. The median follow-up time was 46.8 months (range 0.1-170.4 months).

RESULTS

Hemiarch patients had significantly lower 10-year survival in the matched cohort (hemiarch 73.8%; 66.9-81.4%; vs non-hemiarch 86.5%; 81.1-92.3%; P < 0.001), driven by higher in-hospital mortality rate (4% vs 1%; P < 0.001). Cumulative incidence of aortic arch reintervention rates at 10 years was similarly low (hemiarch 1.0%; 0-2.5% vs non-hemiarch 1.3%; 0-2.6%, P = 0.615). Multivariate analysis with hazard ratios of the overall cohort showed hemiarch as an independent factor associated with long-term mortality (2.16; 1.42-3.27; P < 0.001) but not with aortic arch reintervention (0.76; 0.14-4.07, P = 0.750).

CONCLUSIONS

Hemiarch repair may be associated with higher short-term mortality compared to non-hemiarch. Arch reintervention was rare after a repair of proximal thoracic aortic aneurysm without arch aneurysm. Our data call for larger and prospective studies to further delineate the utility of hemiarch repair in proximal aortic surgery.

Assessment of long-term outcomes: aortic valve reimplantation versus aortic valve and root replacement with biological valved conduit in aortic root aneurysm with tricuspid valve

OBJECTIVES

We compared the long-term outcomes between aortic valve reimplantation [David V (DV)] and aortic valve and root replacement with biological valved conduit [Bentall-De Bono (BD)] for the patients with aortic root aneurysm with tricuspid valve.

METHODS

Among 876 patients who underwent aortic root replacement in our institution between 2005 and 2018, 371 patients who underwent DV (n = 199) or BD (n = 172) for aortic root aneurysm with tricuspid valve were retrospectively reviewed. Exclusion criteria included aortic stenosis, infective endocarditis, previous prosthetic aortic valve, bicuspid aortic valve, aortic dissection and mechanical Bentall procedure. Propensity score matching was performed based on the patient characteristics, matching 90 patients in each group. The primary end point was all-cause mortality. Secondary end points were reoperation for any cause and specifically for aortic valve-related cause.

RESULTS

After propensity score matching, DV and BD groups each had 1 in-hospital mortality (1.1%). Survival at 10 years was 95.3% [95% confidence interval (CI) 85.8-98.5] in DV and 98.6% (95% CI 90.8-99.8) in BD (P = 0.345). The cumulative incidences of reoperation at 10 years in DV versus BD were 3.9% (95% CI 0.7-11.8) vs 18.1% (95% CI 6.9-33.4) for any cause (P = 0.046) and 1.9% (95% CI 0.1-8.8) vs 15.9% (95% CI 5.5-31.4) for aortic valve-related causes (P = 0.032). The reasons for valve-related reoperation were aortic insufficiency (3/5 in DV vs 5/10 in BD), aortic stenosis (0/5 vs 2/10) and infective endocarditis (2/5 vs 3/10).

CONCLUSIONS

Both DV and BD procedures for patients with aortic root aneurysm with tricuspid valve resulted in excellent 10-year survival. All-cause and aortic valve-related reoperations were significantly less frequent with valve-sparing root replacement, suggesting an advantage of DV over biological BD.

Incidence, Cause, and Outcome of Reinterventions after Aortic Root Replacement

BACKGROUND

This study aims to comprehensively characterize the details of the aortic and aortic valve reinterventions after aortic root replacement (ARR).

METHODS

Between 2005 and 2019, 882 patients underwent ARR. The indication was for aneurysm in 666, aortic valve-related in 116, aortic dissection in 64, and infective endocarditis (IE) in 36. Valve-sparing root replacement was performed in 290 while Bio-Bentall was done in 528. Among them, 52 (5.9%) patients required reintervention. The incidence, cause, and time to reintervention, as well as outcomes after reintervention were investigated. Cause-Specific Cox hazard model was performed to identify predictors for reintervention after ARR.

RESULTS

The 10-year cumulative incidence of aortic and aortic valve reintervention after ARR was 10.3% [95%CI, 7.3%-14.0%]. Age per year decrease was the only independent predictor for reintervention [sHR, 0.97; 95%CI, 0.95-0.99]. The causes for 52 reinterventions were: 29 (55.8%) for aortic valve causes including aortic stenosis/insufficiency, and prosthetic valve dysfunction; 15 (28.9%) for IE; 7 (13.5%) for aortic-related causes including pseudoaneurysm, development of aneurysm, and residual dissection; and 1 (1.9%) for coronary button pseudoaneurysm. Median times to reintervention were 11.0 [IQR, 2.0-20.5] months for IE, 24.0 [IQR, 3.7-46.1] months for aortic-related causes, 77.0 [IQR, 28.4-97.6] months for aortic valve-related causes (p=.005). Overall in-hospital mortality after the reinterventions was 7.7% (4/52) with 20.0% with IE (3/15) .

CONCLUSIONS

Reintervention for IE occurs relatively early after ARR while aortic valve- and aortic-related reinterventions gradually increase over time. In-hospital mortality after the reintervention is low, unless it is for IE.

Bicuspid-Associated Aortic Root Aneurysm: Mid to Long-Term Outcomes of David V Versus the Bio-Bentall Procedure

David V valve-sparing root replacement (VSRR) and bio-Bentall (BB) are increasingly performed for aortic root aneurysms associated with a bicuspid aortic valve (BAV). However, durability remains a concern in both procedures. We compared the 10-year outcomes of VSRR vs BB for BAV-associated root aneurysms. A retrospective review identified 134 patients with a BAV-associated root aneurysm who underwent VSRR (n = 65) or BB (n = 69) from 2005 to 2019. Patients with aortic stenosis, endocarditis, previous aortic valve replacement, and emergent cases were excluded. Propensity-score matching was performed, resulting in 2 risk-adjusted groups (n = 40 per group). Median follow-up was 6.21 (1.43-8.28) years. The VSRR cohort was younger (46.0 years vs 56.0 years, P < 0.001) and had a lower incidence of at least moderate aortic insufficiency (AI) (78.5% vs 92.8%, P = 0.02). The incidence of Marfan syndrome, aortic root diameter, and ascending aortic diameter were similar. In-hospital mortality was 1.5% (n = 1) and 1.4% (n = 1) for VSRR and BB, respectively. There was no difference between VSRR and BB in 10-year survival (98.3% [95% confidence interval (CI): 88.6-99.8%] vs 96.2% [95% CI: 85.5-99.0%], P = 0.567) and aortic valve reintervention at 10 years (16.1% [95% CI: 6.3-29.8%] vs 12.9% [95% CI: 3.7-28.0%], P = 0.309). The most common reason for valve reintervention in both groups was AI. Survival and valve reintervention at 10 years were similar in the matched cohort. David V VSRR yields similar mid to long-term outcomes to BB for select patients with a BAV-associated aortic root aneurysm in regards to survival and reintervention rates. Further studies comparing longer term outcomes between root replacement techniques and native valve durability are needed.

Chronic kidney disease stage stratifies short- and long-term outcomes after aortic root replacement

OBJECTIVES

Chronic kidney disease (CKD) is prevalent in patients undergoing cardiovascular surgery, and it negatively impacts procedural outcomes; however, its influence on the outcomes of aortic surgery has not been well studied. This study aims to elucidate the importance of CKD on the outcomes of aortic root replacement (ARR).

METHODS

Patients who underwent ARR between 2005 and 2019 were retrospectively reviewed (n = 882). Patients were divided into 3 groups based on the Kidney Disease: Improving Global Outcomes criteria: Group 1 [estimated glomerular filtration rate (eGFR) ≥ 60 ml/min/1.73 m2, n = 421); Group 2 (eGFR = 30-59 ml/min/1.73 m2, n = 424); and Group 3 (eGFR < 30 ml/min/1.73 m2, n = 37). To reduce potential confounding, a propensity score matching was also performed between Group 1 and the combined group of Group 2 and Group 3. The primary end point was 10-year survival. Secondary end points were in-hospital mortality and perioperative morbidity.

RESULTS

Severe CKD patients presented with more advanced overall chronic and acute illnesses. Kaplan-Meier analysis showed a significant correlation between CKD stage and 10-year survival (log-rank P < 0.001). The number of events for Group 1 was 15, Group 2 was 49 and Group 3 was 11 in 10 years. Group 3 had significantly higher in-hospital mortality (13.5% vs 3.5% in Group 2 vs 0.7% in Group 1, P < 0.001) and stroke (8.1% vs 7.1% vs 1.2%, P < 0.001) as well as introduction to new dialysis (27.0% vs 5.4% vs 1.7%, P < 0.001). eGFR was shown to be an independent predictor of mortality (hazard ratio, 0.98; 95% confidence interval, 0.96-0.99). Comparison between propensity matched groups showed similar postoperative outcomes, and eGFR was still identified as a predictor of mortality (hazard ratio, 0.97; 95% confidence interval, 0.95-0.99).

CONCLUSIONS

Higher stage in CKD negatively impacts the long-term survival in patients who are undergoing ARR.

Feasibility of Transcatheter Aortic Valve Replacement in Prior Aortic Root Surgery: Insights From Virtual Modeling

BACKGROUND

Aortic root replacement (ARR) introduces several anatomic complexities relevant to valve-in-valve (VIV)-transcatheter aortic valve replacement (TAVR) that may (1) increase the risk of coronary obstruction, (2) necessitate transcatheter valve overexpansion to accommodate large annuli, and (3) require alternative vascular access to navigate aortic kinking. Therefore, we aimed to quantify the feasibility of VIV-TAVR in patients who underwent aortic root surgery.

METHODS

Postoperative computed tomography scans were reviewed for consecutive patients who underwent ARR between 2005 and 2019 to obtain measurements relevant for VIV-TAVR planning. Virtual transcatheter valve to coronary ostia distance was measured to assess the risk of coronary obstruction. Root morphologies were classified into 1 of 4 groups based on aortic graft type, aortic diameter at the sinotubular junction, sinus height, estimated transcatheter heart valve height, and diameter. VIV-TAVR was projected to be complex in patients with an aortic kink, extremely large annulus, or heightened risk of coronary obstruction.

RESULTS

Among 848 patients who underwent ARR during the 15-year study period, qualifying contrast-enhanced scans post-ARR were performed in 81 patients. Complex VIV-TAVR was anticipated in 50.6% of subjects. Patients with abnormal root anatomy experienced increased odds of complex VIV-TAVR relative to patients with normal root physiology (ie, sinotubular junction diameter>transcatheter heart valve diameter, sinus height>transcatheter heart valve height) or those who received straight tube grafts (odds ratio, 4.53 [95% CI, 1.02-20.1], P=0.046). The odds of complex VIV-TAVR were also higher among patients who underwent aortic valve replacement-ARR with a stentless bioprosthesis (stentless versus stented, odds ratio, 4.63 [95% CI, 1.40-15.3], P=0.012; stentless versus valve-sparing ARR, odds ratio, 3.78 [95% CI, 1.14-12.5], P=0.029).

CONCLUSIONS

ARR patients with atypical root morphologies or those who underwent valve replacement with stentless bioprostheses may be at high risk for complex VIV-TAVR. Prospective evaluation is required to assess the impact of these conclusions on procedural feasibility.

In Situ Composition of Valved Conduit for Complex Reoperative Aortic Root Replacement

We describe a novel technique, in situ composition of a valved conduit, for complex reoperative aortic root replacement. The absence of a rigid stented aortic valve prosthesis facilitates left ventricular outflow tract (LVOT) reconstruction and coronary reimplantation. First, a Dacron graft, inverted and inserted into the LVOT, is sewn to the LVOT, followed by coronary button reimplantation and then prosthetic valve implantation. For cases that require LVOT reconstruction, the graft below the prosthetic valve serves as a circumferential patch. Our technique requires only surgical materials that are readily available without the need for a specialized skillset.

AB0859 IMPROVEMENTS IN PHYSICAL FUNCTION IN PATIENTS WITH OSTEOARTHRITIS RECEIVING SUBCUTANEOUS TANEZUMAB IN 3 RANDOMIZED CONTROLLED TRIALS

Background:

Tanezumab, a monoclonal antibody against nerve growth factor, is in development for the treatment of the signs and symptoms of osteoarthritis (OA).

Objectives:

To assess the improvement in physical function following treatment with subcutaneous (SC) tanezumab in three Phase 3 OA studies.

Methods:

All three randomized, double-blind, controlled studies enrolled patients (pts) with radiographically-confirmed OA of the hip or knee, who had inadequate response or could not tolerate standard of care analgesics. Study 1 was a dose-titration study (NCT02697773), where pts received two SC doses of: placebo at baseline/week (wk) 8; tanezumab 2.5 mg at baseline/wk 8; or tanezumab 2.5 mg at baseline/5 mg at wk 81. In Study 2 (NCT02709486), pts received three SC doses of placebo, tanezumab 2.5 mg, or 5 mg (at baseline/wk 8/wk 16). In Study 3 (NCT02528188), pts received a stable dose of nonsteroidal anti-inflammatory drugs (NSAIDs) before randomization to double-dummy tanezumab 2.5 mg or 5 mg (at baseline and every 8 wks during a 56 wk treatment period) or twice daily oral NSAIDs. Pts completed Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Physical Function subscale questionnaires in clinic. The least squares (LS) mean (standard error (SE)) change from baseline was calculated for each timepoint up to wk 16 and significance was calculated versus placebo (Studies 1 and 2) or NSAID (Study 3).

Results:

A total of 4541 pts were evaluated (n=696 in Study 1, n=849 in Study 2 and n=2996 in Study 3). In Studies 1 and 2, there were statistically significant improvements from baseline for all tanezumab treated groups versus placebo at wks 2, 4, 8, 12 and 16 (Table 1).In Study 3, the tanezumab 2.5 mg group showed a significant improvement from baseline at wk 2, compared with the NSAID group (Table 2).At wk 4, both tanezumab treatment groups showed a significant improvement from baseline compared with the NSAID group (Table 2). The tanezumab 5 mg group showed a significant improvement from baseline compared with the NSAID group at wks 8 and 16 (Table 2).

Table 1.

Change from baseline in WOMAC Physical Function: Study 1 and 2

Study 1Study 2Tanezumab 2.5 mg n=231Tanezumab 2.5/5 mg n=233Placebon=232Tanezumab 2.5 mg n=283Tanezumab5 mgn=284Placebon=282Wk 2LS mean (SE)-2.89 (0.21)-3.05 (0.21)-2.14 (0.21)-1.95 (0.14)-1.69 (0.14)-1.26 (0.14)p vs placebo0.0004<0.001<.00010.0014Wk 4LS mean (SE)-3.30 (0.21)-3.38 (0.21)-2.28 (0.21)-2.52 (0.15)-2.50 (0.15)-1.71 (0.15)p vs placebo<.0001<.0001<.0001<.0001Wk 8LS mean (SE)-3.17 (0.21)-3.12 (0.21)-2.55 (0.21)-2.38 (0.15)-2.52 (0.15)-1.76 (0.15)p vs placebo0.00570.0114<.0001<.0001Wk 12LS mean (SE)-3.61 (0.22)-3.80 (0.22)-2.75 (0.22)-2.83 (0.16)-2.87 (0.16)-2.04 (0.16)p vs placebo0.0004<.0001<.0001<.0001Wk 16LS mean (SE)-3.22 (0.22)-3.45 (0.22)-2.56 (0.22)-2.68 (0.16)-2.69 (0.16)-2.02 (0.17)p vs placebo0.00650.0002<.0001<.0001Table 2.

Change from baseline in WOMAC Physical Function in Study 3

Tanezumab 2.5 mg n=1002Tanezumab 5 mg n=998NSAID n=996Wk 2LS mean (SE)-1.76 (0.08)-1.64 (0.08)-1.55 (0.08)p vs NSAID0.01500.3286Wk 4LS mean (SE)-2.29 (0.09)-2.31 (0.09)-1.96 (0.09)p vs NSAID0.00040.0001Wk 8LS mean (SE)-2.46 (0.10)-2.69 (0.10)-2.27 (0.10)p vs NSAID0.0517<.0001Wk 16LS mean (SE)-3.27 (0.11)-3.39 (0.11)-3.08 (0.11)p vs NSAID0.06910.0030

Conclusion:

Consistent improvements in WOMAC Physical Function were seen across the first 16 wks for all dose groups of tanezumab-treated pts versus placebo in Study 1 and 2. The tanezumab 5 mg group in Study 3 showed a significant improvement at wks 4, 8 and 16 compared with the NSAID group. Improving physical function could help OA pts attain treatment goals beyond pain relief, improving their ability to perform important daily activities.

References:

[1]Schnitzer, T. J.et al. JAMA 2019

Disclosure of Interests:

Steven P Stanos Consultant of: Pfizer, Sanofi, Scilex, Salix, Speakers bureau: Scilex, Wilson J Chang: None declared, Cory Hultman Employee of: Eli Lilly and Co., Mojgan Sadrarhami Shareholder of: Pfizer Inc., Employee of: Pfizer Inc., Takaharu Yamabe Shareholder of: Pfizer, Employee of: Pfizer, Peter Park Shareholder of: Pfizer Inc., Employee of: Pfizer Inc.

FRI0392 ADVERSE EVENTS IN PATIENTS WITH OSTEOARTHRITIS TREATED WITH SUBCUTANEOUS TANEZUMAB: A POOLED ANALYSIS OF THE OVERALL POPULATION AND SELECTED SUBGROUPS FROM 3 RANDOMISED PLACEBO-CONTROLLED TRIALS

Background:

Tanezumab, a monoclonal antibody against nerve growth factor (NGF), is in development for the treatment of osteoarthritis (OA).

Objectives:

To assess the effects of gender, age and body mass index (BMI) on the incidence of adverse events (AEs) in patients (pts) treated with subcutaneous (SC) tanezumab in pooled data from three phase 3 OA studies. Anti-NGF therapy has been associated with joint safety events1. Here we focus on treatment emergent AEs, including abnormalities of peripheral sensation (APS).

Methods:

All three randomised, double-blind, placebo-controlled studies enrolled pts with radiographically-confirmed OA of the hip or knee, who had inadequate response or could not tolerate standard of care analgesics. In the 16-week (wk) Study 1 (NCT01089725), pts received placebo, tanezumab 2.5 mg, 5 mg or 10 mg at baseline and wk 82. Due to a clinical hold on NGF antibodies, <10% of pts received the 2nddose at wk 8. Pts in the 16-wk Study 2 (NCT02697773), received placebo or tanezumab 2.5 mg at baseline and wk 8 or tanezumab 2.5mg at baseline and 5mg at wk 81. Pts in the 24-wk Study 3 (NCT02709486), received placebo, tanezumab 2.5 mg or 5 mg at baseline, wks 8 and 16. All treatments were given SC. AE data from the treatment period of each study were pooled for placebo, tanezumab 2.5 mg and 5 mg groups and examined by subgroups of gender, age and BMI. Data from the 10 mg group of Study 1 were not included due to the low sample size.

Results:

The incidence of any AE was numerically higher in females across treatment groups and in pts with a BMI ≥30 kg/m2in the tanezumab 5mg, but not 2.5 mg group, vs the overall population (Table 1). SAEs were infrequent but numerically higher across all tanezumab 5 mg subgroups vs placebo (Table 2). Paraesthesia and hypoaesthesia were the most common AEs of APS and were increased in all tanezumab groups in the overall population vs placebo. In any of the subgroups, the incidence of paraesthesia or hypoaesthesia was ≤7.8% and ≤3.9%, respectively. The difference within a patient subgroup for paraesthesia or hypoaesthesia was typically comparable with that of the overall population across treatments.

Table 1.

Incidence of AEs during the treatment period

% of pts with an AE in each subgroupPlacebon=586Tanezumab2.5 mgn=602Tanezumab2.5 mg/5 mg n=219Tanezumab5 mgn=347Overall population51.752.347.054.8Gender Male51.149.741.346.6 Female52.053.650.459.0Age (years) <6555.054.044.054.5 ≥6547.250.052.654.9BMI (kg/m2) <2558.146.651.945.5 25–<3051.455.943.750.0 30–<3549.251.543.258.9 ≥3552.752.355.360.9

BMI, body mass index; kg/m2, kilogram per square metre

Table 2.

Incidence of SAEs during the treatment period

% of pts with a SAE in each subgroupPlacebon=586Tanezumab2.5 mgn=602Tanezumab2.5 mg/5 mg n=219Tanezumab5 mgn=347Overall population1.52.21.42.6Gender Male1.63.01.32.5 Female1.51.71.42.6Age (years) <651.22.61.41.9 ≥652.01.61.33.1BMI (kg/m2) <251.61.102.3 25–<301.62.702.7 30–<351.62.01.43.1 ≥351.32.34.31.6

BMI, body mass index; kg/m2, kilogram per square metre

Conclusion:

This pooled analysis showed that the safety profile of tanezumab in the subgroups studied is broadly similar to that of the overall study population.

References:

[1]Schnitzer, T. J.et al. JAMA(2019)

[2]Birbara, C.et al. J Pain Res(2018)

Disclosure of Interests:

Francis Berenbaum Grant/research support from: TRB Chemedica (through institution), MSD (through institution), Pfizer (through institution), Consultant of: Novartis, MSD, Pfizer, Lilly, UCB, Abbvie, Roche, Servier, Sanofi-Aventis, Flexion Therapeutics, Expanscience, GSK, Biogen, Nordic, Sandoz, Regeneron, Gilead, Bone Therapeutics, Regulaxis, Peptinov, 4P Pharma, Paid instructor for: Sandoz, Speakers bureau: Novartis, MSD, Pfizer, Lilly, UCB, Abbvie, Roche, Servier, Sanofi-Aventis, Flexion Therapeutics, Expanscience, GSK, Biogen, Nordic, Sandoz, Regeneron, Gilead, Sandoz, Alan Kivitz Shareholder of: AbbVie, Amgen, Gilead, GSK, Pfizer Inc, Sanofi, Consultant of: AbbVie, Boehringer Ingelheim,,Flexion, Genzyme, Gilead, Janssen, Novartis, Pfizer Inc, Regeneron, Sanofi, SUN Pharma Advanced Research, UCB, Paid instructor for: Celgene, Genzyme, Horizon, Merck, Novartis, Pfizer, Regeneron, Sanofi, Speakers bureau: AbbVie, Celgene, Flexion, Genzyme, Horizon, Merck, Novartis, Pfizer Inc, Regeneron, Sanofi, Thomas Schnitzer Consultant of: Pfizer, Lilly, AstraZeneca, GSK, Mark Brown Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Sean Donevan Shareholder of: Pfizer Inc., Employee of: Pfizer Inc., Anne Hickman Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Lars Viktrup Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Christine West Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Takaharu Yamabe Shareholder of: Pfizer, Employee of: Pfizer

Sex-related difference in outcomes after aortic root replacement

PURPOSE

Poorer short-term outcomes have been described for females after cardiovascular surgery. We examined the influence of sex on the outcomes after aortic root replacement (ARR).

METHODS

Medical records of 848 patients (females, n = 159/848, 19%) who underwent ARR at our center from 2005 to 2018 were retrospectively reviewed. Sex differences of the following outcomes were analyzed: the primary end point (in-hospital mortality or stro111ke), secondary end point (new requirement for permanent pacemaker), and long-term survival (median follow-up 21.4 months [interquartile range,1.3-60.0]).

RESULTS

Females were significantly older (61.3 vs 58.7 [male]) with higher rates of pre-existing cerebrovascular disease (14% [22/159] vs 7% [52/689]) and previous valve intervention (20% [32/159] vs 13% [89/689]) but less myocardial infarction [1%(1/159) vs 7%(48/689)]. The surgical indication was different (aneurysm 75% [120/159] vs 87% [602/689], dissection 13% [21/159] vs 6% [41/689]; P < .01]). Females had larger average aneurysm size after controlling for body size (P ≤ .001). There was no sex difference in in-hospital mortality (3% [5/159] vs 2% [16/689]) or stroke (4% [7/159] vs 4% [29/689]). Multivariable logistic regression indicated that female sex was not an independent predictor of combined in-hospital stroke or death (odds ratio [OR], 0.59; 95% confidence interval [CI], 0.28-1.25), confirmed by propensity score analysis. There was no difference in long-term survival (5-year survival, 90.96% vs 93.03%; P = .44). Females had higher incidence of permanent pacemaker requirement [11% (18/159) vs 6% (39/689), P = .03] and female sex was an independent predictor of permanent pacemaker requirement (OR, 2.01; 95% CI, 1.085-3.724; P = .03).

CONCLUSIONS

While female patients have different baseline characteristics and indication for ARR, they are not exposed to an increased risk of in-hospital mortality or stroke. However, females experience increased incidence of permanent pacemaker requirement.

Hemodynamic comparison of CoreValve and SAPIEN-XT TAVI valves in Japanese patients

Transcatheter aortic valve implantation (TAVI) is a viable treatment option for high-risk patients with severe aortic stenosis. In Japan, TAVI can be performed using first-generation self-expandable Medtronic CoreValve or balloon-expandable Edwards SAPIEN-XT from 2012. Since the durability and hemodynamic outcomes after transcatheter heart valve (THV) implantation in Japanese patients have not been clearly elucidated, we assessed serial changes in post-TAVI THV performances over a-3-year period by transthoracic echocardiography (TTE). From January 2012 to September 2014, among 83 patients with severe aortic stenosis, 26 underwent TAVI with CoreValve and 57 underwent TAVI with SAPIEN-XT. We assessed the serial changes in first post-implant (FPI) and 3-year post procedure THV hemodynamics by TTE. Valve performance was evaluated by serial assessment of aortic valve mean pressure gradient (PG) and aortic valve area (AVA) assessments. Three-year clinical outcomes were compared between the patients with CoreValve and those with SAPIEN-XT. Seventeen patients with CoreValve and 34 patients with SAPIEN-XT had FPI and 3-year TTEs. The AVA decreased significantly from FPI to 3-year follow-up among patients with SAPIEN-XT, but not among patients with CoreValve. The mean aortic PG decreased significantly from FPI to the 3-year follow-up point among patients with CoreValve; however, it was not significantly different from those with SAPIEN-XT. The absolute change in mean PG from FPI to the 3-year follow-up point decreased significantly among those with CoreValve compared to those with SAPIEN-XT. Clinical outcomes after TAVI were similar for both devices at 3-years after TAVI. In this study, long-term clinical outcomes for CoreValve and SAPIEN XT were similar. The 3-year THV performance of both devices was maintained after TAVI. Serial change in mean aortic PGs for CoreValve decreases significantly from FPI to the 3-year follow-up point compared to that for SAPIEN-XT.

Descending aortic banding for re-rupture of retrograde aortic dissection after emergency thoracic endovascular aortic repair

Conversion to open repair after thoracic endovascular aortic repair (TEVAR) for acute type B aortic dissection is rare, but inevitable. We present a case of an 86-year-old man with ruptured type B aortic dissection after TEVAR. He received a successful stent-graft implantation of the descending aorta without any type of endoleak. After the patient was transferred to the intensive care unit, he went into a shock state. Contrast-enhanced CT revealed a re-rupture of acute retrograde type B aortic dissection. The false lumen was patent and perforated to the left thorax. Left thoracotomy and descending aortic banding was performed. Descending aorta was encircled with a woven Dacron graft at the distal part of the rupture site to compress the patent false lumen. The bleeding was stopped, and the follow-up CT showed false lumen thrombosis. Descending aortic banding is one of the quick and effective open conversion techniques.

Renin–angiotensin system blockade therapy after transcatheter aortic valve implantation

Objective

The persistence of left ventricular (LV) hypertrophy is associated with poor clinical outcomes after transcatheter aortic valve implantation (TAVI) for aortic stenosis. However, the optimal medical therapy after TAVI remains unknown. We investigated the effect of renin−angiotensin system (RAS) blockade therapy on LV hypertrophy and mortality in patients undergoing TAVI.

Methods

Between October 2013 and April 2016, 1215 patients undergoing TAVI were prospectively enrolled in the Optimized CathEter vAlvular iNtervention (OCEAN)-TAVI registry. This cohort was stratified according to the postoperative usage of RAS blockade therapy with angiotensin-converting enzyme (ACE) inhibitors or angiotensin-receptor blockers (ARBs). Patients with at least two prescriptions dispensed 180 days apart after TAVI and at least a 6-month follow-up constituted the RAS blockade group (n=371), while those not prescribed any ACE inhibitors or ARBs after TAVI were included in the no RAS blockade group (n=189).

Results

At 6 months postoperatively, the RAS blockade group had significantly greater LV mass index regression than the no RAS blockade group (−9±24% vs −2±25%, p=0.024). Kaplan-Meier analysis revealed a significantly lower cumulative 2-year mortality in the RAS blockade than that in the no RAS blockade group (7.5% vs 12.5%; log-rank test, p=0.031). After adjusting for confounding factors, RAS blockade therapy was associated with significantly lower all-cause mortality (HR, 0.45; 95% CI 0.22 to 0.91; p=0.025).

Conclusions

Postoperative RAS blockade therapy is associated with greater LV mass index regression and reduced all-cause mortality. These data need to be confirmed by a prospective randomised controlled outcome trial.

Impact of the Clinical Frailty Scale on Outcomes After Transcatheter Aortic Valve Replacement

Background:

The semiquantitative Clinical Frailty Scale (CFS) is a simple tool to assess patients’ frailty and has been shown to correlate with mortality in elderly patients even when evaluated by nongeriatricians. The aim of the current study was to determine the prognostic value of CFS in patients who underwent transcatheter aortic valve replacement.

Methods:

We utilized the OCEAN (Optimized Catheter Valvular Intervention) Japanese multicenter registry to review data of 1215 patients who underwent transcatheter aortic valve replacement. Patients were categorized into 5 groups based on the CFS stages: CFS 1-3, CFS 4, CFS 5, CFS 6, and CFS ≥7. We subsequently evaluated the relationship between CFS grading and other indicators of frailty, including body mass index, serum albumin, gait speed, and mean hand grip. We also assessed differences in baseline characteristics, procedural outcomes, and early and midterm mortality among the 5 groups.

Results:

Patient distribution into the 5 CFS groups was as follows: 38.0% (CFS 1-3), 32.9% (CFS4), 15.1% (CFS 5), 10.0% (CFS 6), and 4.0% (CFS ≥7). The CFS grade showed significant correlation with body mass index (Spearman’s ρ=−0.077, P =0.007), albumin (ρ=−0.22, P <0.001), gait speed (ρ=−0.28, P <0.001), and grip strength (ρ=−0.26, P <0.001). Cumulative 1-year mortality increased with increasing CFS stage (7.2%, 8.6%. 15.7%, 16.9%, 44.1%, P <0.001). In a Cox regression multivariate analysis, the CFS (per 1 category increase) was an independent predictive factor of increased late cumulative mortality risk (hazard ratio, 1.28; 95% confidence interval, 1.10–1.49; P <0.001).

Conclusions:

In addition to reflecting the degree of frailty, the CFS was a useful marker for predicting late mortality in an elderly transcatheter aortic valve replacement cohort.

Oral apixaban for the treatment of venous thromboembolism in cancer patients: results from the AMPLIFY trial

BACKGROUND

The AMPLIFY trial compared apixaban with enoxaparin followed by warfarin for the treatment of acute venous thromboembolism (VTE).

OBJECTIVE

To perform a subgroup analysis to compare the efficacy and safety of apixaban and enoxaparin followed by warfarin for the treatment of VTE in patients with cancer enrolled in AMPLIFY.

PATIENTS/METHODS

Patients with symptomatic VTE were randomized to a 6-month course of apixaban or enoxaparin followed by warfarin. The primary efficacy outcome and principal safety outcome were recurrent VTE or VTE-related death and major bleeding, respectively.

RESULTS

Of the 5395 patients randomized, 169 (3.1%) had active cancer at baseline, and 365 (6.8%) had a history of cancer without active cancer at baseline. Among patients with active cancer, recurrent VTE occurred in 3.7% and 6.4% of evaluable patients in the apixaban and enoxaparin/warfarin groups, respectively (relative risk [RR] 0.56, 95% confidence interval [CI] 0.13-2.37); major bleeding occurred in 2.3% and 5.0% of evaluable patients, respectively (RR 0.45, 95% CI 0.08-2.46). Among patients with a history of cancer, recurrent VTE occurred in 1.1% and 6.3% of evaluable patients in the apixaban and enoxaparin/warfarin groups, respectively (RR 0.17, 95% CI 0.04-0.78); major bleeding occurred in 0.5% and 2.8% of treated patients, respectively (RR 0.20, 95% CI 0.02-1.65).

CONCLUSIONS

The results of this subgroup analysis suggest that apixaban is a convenient option for cancer patients with VTE. However, additional studies are needed to confirm this concept and to compare apixaban with low molecular weight heparin in these patients.

Efficacy of Tolvaptan in Patients with Volume Overload after Cardiac Surgery

<strong>Background:</strong> The vasopressin type 2 receptor antagonist tolvaptan (TLV) has recently become available for treating congestion. However, there is no evidence confirming the efficacy of TLV for patients with volume overload after cardiac surgery. Here, we retrospectively studied the efficacy of TLV in patients with volume overload after cardiac surgery. <br /><strong>Methods:</strong> We enrolled a total of 39 patients who had volume overload after cardiac surgery and who were treated with our protocol of body fluid management. The primary endpoint of this study was to evaluate the hospitalization period, while the secondary endpoints were to estimate adverse events such as hypotension, electrolyte abnormality, presence or absence of renal dysfunction and liver damage, and the incidence of atrial fibrillation (AF). <br /><strong>Results:</strong> The hospitalization period of the T (TLV) and C (furosemide and spironolactone) groups was 12.3 ± 2.6 days and 14.7 ± 4.4 days, respectively (P = .044), the mean urine volume was 2761.5 ± 850.3 mL/day and 2205.2 ± 598.5 mL/day, respectively (P = .024), and the incidence of postoperative AF after diuretics administration was 2/19 (11%) and 9/17 (52%), respectively. <br /><strong>Conclusion:</strong> TLV successfully and rapidly improved organ congestion without causing hemodynamic abnormalities (hypotension, arrhythmia development), electrolyte abnormality, liver damage or renal dysfunction, thus significantly reducing the period of hospitalization.

Midterm Outcome of Mitral Valve Repair with Artificial Chordae for Only Posterior Leaflet Disease-Comparison with the Resectional Technique in a Single Institute

OBJECTIVE

We compared the midterm results of mitral valve repair with and without leaflet resection, and revealed the effectiveness of this technique, even for in the posterior leaflet alone.

PATIENTS

From August 2002 to March 2014, a total of 306 mitral valve repairs were carried out at our hospital. Of these patients, 50 cases did not undergo leaflet resection (Artificial Chordae; Group A) and 56 cases underwent leaflet resection (Resectional; Group R). There were no significant differences in the preoperative profiles.

RESULTS

The follow up rate was 98% and 100% respectively. The mean cardiopulmonary bypass time and aortic cross clamp time were not significantly different. The average ring size was significantly larger (p <0.01) in Group A. All cause mortality at 3 years and 8 years was both 97.8% in Group A and was both 98.1% in Group R. Freedom from moderate mitral regurgitation at 3 years was 97.1% and at 8 years was 91.7% in Group A and 97.4% and 94.6% in Group R respectively. There were no cases of mortality, re-operation for recurrent mitral regurgitation, hemolytic anemia and infectious endocarditis.

CONCLUSION

We demonstrated good midterm results in mitral valve repair without leaflet resection. However, further follow-up was needed.

[Early Results of Minimally Invasive Cardiac Surgery (MICS) Mitral Valve Surgery with 51 Cases]

BACKGROUND

Minimally invasive cardiac surgery of the mitral valve (MICS-MV) has become the routine approach to mitral valve disease in some centers. We reported early results of 51 cases of MICS-MV.

METHOD

The preoperative variables, intraoperative date and postoperative outcomes of patients undergoing MICS-MV and conventional surgery of the mitral valve were collected from January 2013 to August 2014.

RESULTS

Aortic cross clamp and cardio-pulmonary bypass( CPB) time were longer in this series than in the conventional median sternotomy. We experienced complications and 2 patients required mitral valve replacement (MVR) due to failure of repair in initial MICS cases. One case of the patients with infective endocarditis was performed conversion of from MICS to a median sternotomy due to left ventricle(LV) rupture.

CONCLUSION

The early-time outcomes in these patients are acceptable. We think that large number of MICS-MV operations are required to overcome the learning curve.

[Succesful case of open heart surgery in a dialysis patient with infectious endocarditis and severe bone marrow suppression: report of a case]

We report a case of infectious endocarditis due to Corynebacterium species. The patient was 71-yearold man, who was on dialysis and had tracheostomy preoperatively. He went to the hospital complaining of dyspnea. He was diagnosed with congestive heart failure and treated after admission. His respiratory condition was exacerbated and he was intubated. Respiratory management prolonged over 2 weeks. Tracheostomy was performed. One month after admission, cardiac echo showed massive aortic valve regurgitation and vegetation of aortic valve. The patient was transferred to our hospital to undergo operation for aortic valve regurgitation and infectious endocarditis. In our hospital, labo data showed severe bone marrow suppresssion with white blood cell(WBC)1,700/µl, red blood cell(RBC)259×104/µl, platelet(PLT) 5.0×104/µl. Aortic valve replacement was performed. Because the patient had tracheostomy, we incised sternal bone in a T shape to avoid mediastinitis. After operation, patient recovered well and left hospital 48th day after the operation.

[Prevention of cerebral infarction in thoracic endovascular aneurysm repair(TEVAR) of distal aortic arch aneurysms; left subclavian artery balloon technique]

Thoracic endovascular aneurysm repair(TEVAR) has been applied more and more frequently to an atherosclerotic distal aortic arch aneurysm. Even if the procedure is successful, extensive cerebral infarction might occur, especially in the left vertebral artery area. We therefore devised a new method to prevent embolic events using a thrombectomy catheter with an end hole, which was placed at the origin of the letf subclavian artery via the radial artery. This simple left subclavian artery balloon technique not only prevents cerebral embolism in the left vertebral artery system, but also provides a position marker under X-ray, and enables tight compaction of the embolization coils.

Modified reduction aortoplasty with external reinforcement of the ascending aortic aneurysm caused by giant cell arteritis treated as polymyalgia rheumatica

A 74-year-old Japanese woman was referred to our hospital for surgical repair of an ascending aortic aneurysm and severe aortic valve regurgitation. She had received low dose steroid treatment for 6 years due to a diagnosis of the polymyalgia rheumatica (PMR), and no signs of inflammation were detected serologically. Modified reduction aortoplasty with external prosthetic support of the ascending aorta was performed following uneventful aortic valve replacement under cardiopulmonary bypass. The macroscopic view of the ascending aortic wall showed the diffuse spotty medial defects. The pathological interpretation of the aneurysmal wall was giant cell arteritis (GCA). Because PMR is intimately associated with GCA, physicians should be aware of the development of thoracic aortic aneurysm even in the course of PMR. Reduction aortoplasty is simple and may not be precluded from the treatment option for the aortic dilatation associated with giant cell arteritis.

Preliminary assessment of the safety and efficacy of tanezumab in Japanese patients with moderate to severe osteoarthritis of the knee: a randomized, double-blind, dose-escalation, placebo-controlled study

OBJECTIVE

To investigate the use of tanezumab, a humanized monoclonal antibody that inhibits nerve growth factor, for the treatment of moderate to severe osteoarthritis in Japanese patients.

DESIGN

Patients received tanezumab 10, 25, 50, 100, 200 μg/kg, or placebo and were followed for 92 or 120 days. Endpoints included the incidence of adverse events (AEs) and the change from baseline to week 8 in pain intensity and the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) subscales.

RESULTS

Patients (n = 83) were 69% female, age 44-73 years, with a Kellgren-Lawrence X-ray grade of 2-4. At week 8, compared with placebo, tanezumab 25, 100, and 200 μg/kg improved index knee pain during walking (-18.5, -14.3, and -27.6, respectively), index knee pain in the past 24 h (-19.1, -14.6, and -24.2, respectively), current index knee pain (-16.5, -10.9, and -22.8, respectively), and the WOMAC pain (-11.5, -9.6, and -18.8, respectively), physical function (-8.7, -9.5, and -17.6, respectively), and stiffness (-20.4, -11.2, and -10.2, respectively) subscales. Overall, seven patients reported AEs of abnormal peripheral sensation: allodynia (two in the tanezumab 200 μg/kg group); paresthesia (two in the tanezumab 200 μg/kg group), dysesthesia (one in the tanezumab 200 μg/kg group); thermohypoesthesia (one in the tanezumab 100 μg/kg group), and decreased vibratory sense (one in the placebo group). All of these AEs were mild to moderate in severity and transient in nature.

CONCLUSIONS

Tanezumab was safe and generally well tolerated and may improve pain symptoms in Japanese patients with moderate to severe osteoarthritis of the knee. CLINICALTRIALS.GOV IDENTIFIER: NCT00669409.

Nitridation of Si(100)-( 2x1) surface by NH3: a quantum chemical cluster model study

Based on density functional cluster model calculations, we present the first detailed mechanisms for the complete decomposition of NH3 to NHx(a) (x = 0-2) on the Si(100)-(2x1) surface. Three kinds of elementary processes, namely, N-H bond cleavage, NHx(a) insertion into the Si-Si surface dimer bond or backbond, and H2 libration, are investigated. A plausible microscopic mechanism for the nitridation of Si(100)-(2x1) surface by NH3 is proposed.

First observation of clusters for solvated tropylium ions

We have first observed clusters for solvated tropylium ions (Tr+(ROH)n) which were isolated from ROH-CH3CN (1:1 by vol.; R = Me, Et, and Prn) solutions by using a specially designed mass spectrometer and found the clear-cut essential features concerning the solvation structure around Tr+.

Synthesis, structure, and H2O2-dependent catalytic functions of disulfide-bridged dicopper(I) and related thioether-copper(I) and thioether-copper(II) complexes

A disulfide-bridged dicopper(I) complex, [Cu2(Py2SSPy2)](ClO4)2 (1) (Py2SSPy2 = bis(2-[N,N-bis(2-pyridylethyl)-amino]-1,1- dimethylethyl)disulfide), a thioether-copper(I) complex, [Cu(iPrSPy2)](ClO4) (2) (iPrSPy2 = N-(2-isopropylthio-2-methyl)propyl-N,N-bis-2-(2-pyridyl)ethylamine, and a thioether-copper(II) complex, [Cu-(PheSPy2)(H2O)](ClO4)2 (3) (PheSPy2 = N-(2-methyl-2-phenethylthio)propyl-N,N-bis-2-(2- pyridyl)ethylamine), were newly synthesized by the reactions of Cu(ClO4)2.6H2O with a thiol ligand of Py2SH (N,N-bis[2-(2-pyridyl)-ethyl]-1,1-dimethyl-2- mercaptoethylamine) and thioether ligands of iPrSPy2 and PheSPy2, respectively. For complexes 1 and 2, X-ray analyses were performed. Complex 1 crystallizes in the triclinic space group P1, and complex 2 crystallizes in the orthorhombic space group Pbca with the following unit cell parameters: for 1, a = 15.165 (3) A, b = 22.185 (4) A, c = 14.989 (3) A, alpha = 105.76 (1) degrees, beta = 90.82 (2) degrees, gamma = 75.23 (1) degrees, and Z = 2; for 2, a = 17.78 (2) A, b = 17.70 (1) A, c = 15.75 (1) A, and Z = 8. Complex 1 is the first structurally characterized example obtained by the redox reaction Cu(II) + RSH-->Cu(I) + RSSR and has two independent structures (1a, 1b) which mainly differ in S-S bond distances, Cu(I)...Cu(I) separations, and C-S-S-C dihedral angles of the disulfide units. The S-S bond distances of 2.088(7) A in 1a and 2.070(7) A in 1b are indicative of significant activation of the S-S bonds by the dicopper centers. Fragment molecular orbital (FMO) analyses and molecular orbital overlap population (MOOP) analyses based on the extended Hückel method clarify the preferable formation of the disulfide S-S bond in 1 rather than the formation of a thiolate-copper(II) complex within the Py2S- ligand framework. Catalytic functions of complexes 1-3 were investigated with peroxides (H2O2 and tBuOOH) as oxidants. Complex 1 catalyzed the selective oxidation of cyclohexane to cyclohexanol and mediated the cyclohexene epoxidation in the presence of H2O2. A transient dark green intermediate observed in the reaction of 1 with H2O2 is characterized by UV-vis, EPR, and resonance Raman spectroscopies, identifying it as a Cu(II)-OOH species, 1(OOH). The resonance Raman features of the nu(O-O) bands at 822 and 836 cm-1, which are red-shifted to 781 and 791 cm-1, respectively, upon introduction of H2(18)O2, are indicative of formation of two kinds of Cu-OOH species rather than the Fermi doublet and the significant weakening of the O-O bonds. These mechanistic studies demonstrate that by virtue of the electron-donating ability of the disulfide unit the Cu-OOH species can be actually activated for one-electron oxidation, which has been reported so far unfavorable for other vibrationally characterized Cu-OOH species.

Direct participation of potassium ion in the catalysis of coenzyme B(12)-dependent diol dehydratase

The direct ion-dipolar interactions between potassium ion (K(+)) and the two hydroxyl groups of the substrate are the most striking feature of the crystal structure of coenzyme B(12)-dependent diol dehydratase. We carried out density-functional-theory computations to determine whether K(+) can assist the 1,2-shift of the hydroxyl group in the substrate-derived radical. Between a stepwise abstraction/recombination reaction proceeding via a direct hydroxide abstraction by K(+) and a concerted hydroxyl group migration assisted by K(+), only a transition state for the latter concerted mechanism was found from our computations. The barrier height for the transition state from the complexed radical decreases by only 2.3 kcal/mol upon coordination of the migrating hydroxyl group to K(+), which corresponds to a 42-fold rate acceleration at 37 degrees C. The net binding energy upon replacement of the K(+)-bound water for substrate was calculated to be 10.7 kcal/mol. It can be considered that such a large binding energy is at least partly used for the substrate-induced conformational changes in the enzyme that trigger the homolytic cleavage of the Co-C bond of the coenzyme and the subsequent catalysis by a radical mechanism. We propose here a new mechanism for diol dehydratase in which K(+) plays a direct role in the catalysis.

Triplet State of Würster's Blue-Based Di(cation radical)

[reaction: see text] N,N-bis[4-(dimethylamino)phenyl]-N,N'-dimethyl-1,3-benzenediamine was prepared in order to investigate the corresponding Würster blue-based di(cation radical). The generated diradical was found to be a ground-state triplet, and moreover, the observed ESR spectrum had no definite fine structure, suggesting a mixture of some conformers.

Micelle Formation of Anionic Surfactant with Divalent Counterion of Separate Electric Charge

The critical micelle concentration (CMC) of the anionic surfactant, 1,1'-(1,omega-decanediyl) bispyridinium hexadecane-1-sulfonate (C10BP(C16)2) was determined by electrical conductivity measurements at various temperatures. The degree of counterion binding to micelles was evaluated from the change in CMC with total counterion concentration. The molecular weight of the micelles was determined by static light scattering. The mass action model was applied to micelle formation in order to calculate the three micellization parameters, the micellization constant, the micelle aggregation number, and the number of counterions per micelle. Thermodynamic parameters (DeltaG0, DeltaH0, -TDeltaS0) for the micellization were evaluated by their temperature dependence. The findings were: (1) Micelle formation was entropy-driven over the whole temperature range examined. (2) C10BP(C16)2 had a higher degree of counterion binding to micelles compared with those of monovalent counterion. (3) The plots of log CMC against the carbon number of the homologous surfactant ions gave a straight line, indicating that free energy change per methylene group for micelle formation was -1.18RT for surfactant ions. Copyright 1999 Academic Press.

Intestinal absorption of calcium from calcium ascorbate in rats

The intestinal absorption of calcium (Ca) from Ca ascorbate (Ca-AsA) was investigated in normal rats. Each animal was perorally administered either 5mg (low dose) or 10mg (high dose) of Ca in 1ml of distilled water as Ca-AsA, Ca carbonate (CaCO3), or Ca chloride (CaCl2), which were intrinsically labeled with 45Ca using 45CaCl2. The amount of radioactivity in plasma was measured periodically up to 34h after dosing, and pharmacokinetic parameters were calculated from the radioactivity in plasma. The time taken to reach the maximum 45Ca level (Tmax) did not differ among the three groups. The area under the plasma 45Ca level/time curve (AUCinfinity) value for the Ca-AsA group was significantly higher than those for the CaCO3 and the CaCl2 groups. The radioactivity at Tmax (Cmax) for the Ca-AsA group was significantly higher than those for the CaCO3 and the CaCl2 groups for the low dose, and comparable with or significantly higher than those for the CaCl2 and CaCO3 groups for the high dose. Similar results were observed for whole-body 45Ca retention. Radioactivity in the femur 34h after dosing was the highest in the Ca-AsA group and the lowest in the CaCO3 group. The rank order of solubility in water, the first fluid (pH 1.2, JP-1) of JPXIII disintegration medium, acetate buffer solution (pH 4.0), triethanolamine-malate buffer solution (pH 7.0) and ammonium chloride buffer solution (pH 10.0) at 37 degrees C was CaCl2 > Ca-AsA > CaCO3. In contrast, the rank order of the solubility in the second fluid (pH 6.8, JP-2) of JPXIII disintegration medium at 37 degrees C was Ca-AsA > CaCl2 > CaCO3. These results indicate that the absorbability of Ca from Ca-AsA is almost comparable with, or higher than, that from CaCl2 and significantly higher than that from CaCO3 because of its high degree of solubility in the intestine. Therefore, Ca-AsA would be useful as a Ca supplement with relatively high absorption from intestine.

[Late phase II trial of oral etoposide administered for 21 consecutive days in patients with cervical cancer. ETP 21 Study Group--Cervical Cancer Group]

We conducted a multi-site late phase II trial of oral etoposide administered for 21 consecutive days in patients with cervical cancer in cooperation with 32 institutes. Fifty mg/body of oral etoposide was administered daily for 21 consecutive days. Treatment cycles were to be repeated at 4- to 5-week intervals. Eighty patients were enrolled and 70 patients were evaluated. The overall response rate (95% CI), including one complete response patient and 18 partial response patients, was 27.1% (19/70). The most commonly observed toxicity was myelosuppression such as leukopenia, neutropenia, hemoglobin decrease and thrombocytopenia. Other adverse effects were gastrointestinal toxicities such as anorexia, nausea, stomatitis and vomiting, as well as fatigue and alopecia. These adverse effects were well tolerated and controlled with medications. From these results we concluded oral etoposide administered for 21 consecutive days was an effective drug against cervical cancer.

[Early phase II trial of oral etoposide administered for 21 consecutive days in patients with cervical or ovarian cancer. ETP 21 Study Group--Cervical-Ovarian Cancer Group]

We conducted multi-site early phase II trial or oral etoposide administered for 21 consecutive days in patients with cervical or ovarian cancer in cooperation with 19 institutes. Fifty mg/body of oral etoposide was administered daily for 21 consecutive days. Cycles were repeated every 28 days. In cervical cancer, 24 patients were enrolled and 17 of them were evaluated. The overall response rate including CR and PR was 23.5% (4/17). In ovarian cancer, 18 patients out of 21 enrolled were evaluated. The overall response rate was 16.7% (3/18). The primary toxicity observed was myelosuppression such as leukopenia, neutropenia, hemoglobin decrease and thrombocytopenia. Other adverse effects were anorexia, nausea, vomitting, fatigue, alopecia and stomatitis. From these results we concluded that oral etoposide administered for 21 consecutive days was effective against cervical cancer.

Comparative study of dobutamine stress electron-beam computed tomography and exercise thallium scintigraphy in the diagnosis of patients with suspected coronary artery disease

To evaluate the diagnostic value of dobutamine stress electron-beam computed tomography (EBCT) as compared with exercise stress thallium-201 single-photon emission computed tomography (201T1-SPECT) for the detection of myocardial ischemia, 10 patients with proven or suspected coronary artery disease underwent both tests. Nine of the 10 patients also underwent coronary angiography. EBCT images were analyzed objectively to evaluate systolic wall thickening and analyzed segmentally to determine the distribution of the coronary arteries. Dobutamine stress EBCT revealed the presence of ischemia in 59 segments, whereas exercise stress 201T1-SPECT revealed ischemia in 51 segments (agreement = 73%). The advantage of dobutamine stress EBCT was demonstrated in the inferior/posterior segments as compared with the results of exercise stress 201T1-SPECT. The overall sensitivity for detecting ischemic regions supplied by coronary arteries with significant stenosis (diameter stenosis > 50%) was 83% for dobutamine stress EBCT and 79% for exercise stress 201T1-SPECT (p = NS), with specificities of 75% and 82% (p = NS). Thus, dobutamine stress EBCT presents a reasonable alternative to exercise stress 201T1-SPECT for the objective assessment of patients with suspected coronary artery disease.

Induction of the 2B9 antigen/dipeptidyl peptidase IV/CD26 on human natural killer cells by IL-2, IL-12 or IL-15

Activation of human natural killer (NK) cells involves sequential events including cytokine production and induction of cell surface molecules, resulting in the enhancement of cytolytic activity. To delineate the activation process of NK cells, we generated murine monoclonal antibodies (mAbs) against YT, a human large granular lymphocyte/natural killer (LGL/NK) cell line. Among the mAbs reactive with YT cells, one mAb, termed 2B9, was noted because of the lack of reactivity with most of the human T- and B-cell lines tested. In fresh peripheral blood mononuclear cells (PBMC), however, the majority of cells expressing this antigen (Ag) were T cells but not CD16+ nor CD56+ NK cells. Since YT cells showed an activated phenotype expressing interleukin-2 (IL-2) receptor alpha chain, we examined whether 2B9 Ag could be induced on normal human peripheral blood NK cells by cytokines known to activate NK cells. The 2B9 Ag was induced on NK cells by IL-2, IL-12 or IL-15 while no induction was observed by interferon-gamma (IFN-gamma). Biochemical analysis showed that anti-2B9 mAb recognized a 115 kDa molecule in YT cells. A cDNA clone encoding the 2B9 Ag was isolated from a cDNA expression library of YT cells and its sequence was identical to CD26 cDNA although it was not of full length. Transient expression of the 2B9 cDNA on COS-7 cells revealed that this cDNA encodes the antigenic epitope(s) recognized by anti-2B9 mAb as well as Ta1, an anti-CD26 mAb. These results showed that the 2B9 Ag is identical to CD26, and demonstrated that CD26 is an activation antigen on CD16+ CD56+ NK cells inducible by IL-2, IL-12 or IL-15.

Expression of estrogen and progesterone receptors in endometrium and peritoneal endometriosis: an immunohistochemical and in situ hybridization study

OBJECTIVE

To clarify the role of ovarian steroids in the development and progression of endometriosis, estrogen receptors (ERs) and progesterone receptors (PRs) were localized by immunohistochemistry, and ER messenger RNA (mRNA) was detected by in situ hybridization in the uterine endometrium and in normal and altered pelvic peritoneum.

DESIGN

Retrospective and prospective study.

SETTING

Nagasaki University School of Medicine, Nagasaki, Japan.

PATIENT(S)

A retrospective study of 61 formalin-fixed uterine endometria and normal and altered pelvic peritonea from patients suffering from various gynecologic diseases was conducted. In addition, in 22 fresh frozen tissue specimens, ER mRNA expression was evaluated prospectively.

MAIN OUTCOME MEASURE(S)

In formalin-fixed tissues, ER and PR were localized immunohistochemically. The results of immunohistochemical staining were scored from 0 to 4, depending on the signal intensity and frequency of positive cells. In fresh frozen specimens, ER mRNA expression was assessed by nonradioactive in situ hybridization using thymine-thymine dimerized oligonucleotide probes.

RESULTS

The highest score of ERs and PRs was observed in the epithelial and stromal cells of the normal uterine endometrium at the early proliferative phase of the menstrual cycle. The ER and PR scores declined throughout the secretory phase. In typical endometriotic lesions, the ER and PR scores were constantly high independent of the menstrual cycle. The expression pattern of ER mRNA was mostly in parallel with that of ERs. In typical endometriosis, ERs and PRs were found in both glandular epithelial cells and their surrounding stromal cells. Expression of ER mRNA was found in typical endometriotic peritonea and in pelvic peritoneum with columnar epithelial cells, but not in normal pelvic peritoneum (mesothelium). Estrogen receptors and PRs were negative in mesothelium, but were positive in the nuclei of fibroblasts in the connective tissue.

CONCLUSION(S)

We demonstrated the expression of ERs, ER mRNA, and PRs in the columnar cells in pelvic peritonea and typical endometriosis, but not in normal mesothelium. These results suggest that endometriosis may originate from the columnar cells with ERs and PRs in the pelvic peritoneal lining.