Additional cusp reconstruction does not compromise valve durability and mid-term survival after the David procedure: results from 449 patients.

OBJECTIVES: The aim of this study was to evaluate whether additional cusp interventions and valve types affect aortic valve-related reoperation and mortality rates after the David procedure. METHODS: Between 1997 and 2018, a total of 449 patients {372 males; mean age 54.2 [standard deviation (SD) 15.2] years, range: 12.7-79.9 years} underwent elective valve-sparing aortic root replacement (David procedure) for aortic regurgitation and were prospectively followed up clinically and echocardiographically. RESULTS: The follow-up was 94% complete. Cumulative follow-up time was 2268 patient-years [mean follow-up time 5.1 (4.3 SD) years]. Thirty-day mortality was 2.2% (n = 10). Late (>30 days) survival did not differ from that of the age- and gender-matched general population. Freedom from reoperation in patients without additional cusp reconstruction was 94% [95% confidence interval (CI) 91-98] and 92% (95% CI 88-97) at 5 and 10 years, respectively, which was not significantly different (P = 1) for patients who did require additional cusp reconstruction 98% (95% CI 95-100) and 89% (95% CI 81-99). In patients with tricuspid aortic valves (n = 338), freedom from reoperation was 96% (95% CI 94-99) and 93% (95% CI 88-97) at 5 and 10 years, respectively. Patients with bicuspid aortic valves (n = 111) had a freedom from reoperation of 94% (95% CI 89-99) at 5 years and 88% (95% CI 79-98) at 10 years (P = 0.021 for the comparison to tricuspid aortic valve). Overall, 23 patients (5%; 1%/patient-year) required reoperation with a mean interval of 4.5 (4.8 SD) months. CONCLUSIONS: The David procedure revealed low mid-term reoperation risk and excellent survival independent of adjunctive cusp interventions/valve morphology and is comparable with that of the age- and gender-matched general population.

Multimodality Molecular Imaging of Cardiac Cell Transplantation: Part II. In Vivo Imaging of Bone Marrow Stromal Cells in Swine with PET/CT and MR Imaging.

Purpose To quantitatively determine the limit of detection of marrow stromal cells (MSC) after cardiac cell therapy (CCT) in swine by using clinical positron emission tomography (PET) reporter gene imaging and magnetic resonance (MR) imaging with cell prelabeling. Materials and Methods Animal studies were approved by the institutional administrative panel on laboratory animal care. Seven swine received 23 intracardiac cell injections that contained control MSC and cell mixtures of MSC expressing a multimodality triple fusion (TF) reporter gene (MSC-TF) and bearing superparamagnetic iron oxide nanoparticles (NP) (MSC-TF-NP) or NP alone. Clinical MR imaging and PET reporter gene molecular imaging were performed after intravenous injection of the radiotracer fluorine 18-radiolabeled 9-[4-fluoro-3-(hydroxyl methyl) butyl] guanine ((18)F-FHBG). Linear regression analysis of both MR imaging and PET data and nonlinear regression analysis of PET data were performed, accounting for multiple injections per animal. Results MR imaging showed a positive correlation between MSC-TF-NP cell number and dephasing (dark) signal (R(2) = 0.72, P = .0001) and a lower detection limit of at least approximately 1.5 × 10(7) cells. PET reporter gene imaging demonstrated a significant positive correlation between MSC-TF and target-to-background ratio with the linear model (R(2) = 0.88, P = .0001, root mean square error = 0.523) and the nonlinear model (R(2) = 0.99, P = .0001, root mean square error = 0.273) and a lower detection limit of 2.5 × 10(8) cells. Conclusion The authors quantitatively determined the limit of detection of MSC after CCT in swine by using clinical PET reporter gene imaging and clinical MR imaging with cell prelabeling. (©) RSNA, 2016 Online supplemental material is available for this article.

Multimodality Molecular Imaging of Cardiac Cell Transplantation: Part I. Reporter Gene Design, Characterization, and Optical in Vivo Imaging of Bone Marrow Stromal Cells after Myocardial Infarction.

Purpose To use multimodality reporter-gene imaging to assess the serial survival of marrow stromal cells (MSC) after therapy for myocardial infarction (MI) and to determine if the requisite preclinical imaging end point was met prior to a follow-up large-animal MSC imaging study. Materials and Methods Animal studies were approved by the Institutional Administrative Panel on Laboratory Animal Care. Mice (n = 19) that had experienced MI were injected with bone marrow-derived MSC that expressed a multimodality triple fusion (TF) reporter gene. The TF reporter gene (fluc2-egfp-sr39ttk) consisted of a human promoter, ubiquitin, driving firefly luciferase 2 (fluc2), enhanced green fluorescent protein (egfp), and the sr39tk positron emission tomography reporter gene. Serial bioluminescence imaging of MSC-TF and ex vivo luciferase assays were performed. Correlations were analyzed with the Pearson product-moment correlation, and serial imaging results were analyzed with a mixed-effects regression model. Results Analysis of the MSC-TF after cardiac cell therapy showed significantly lower signal on days 8 and 14 than on day 2 (P = .011 and P = .001, respectively). MSC-TF with MI demonstrated significantly higher signal than MSC-TF without MI at days 4, 8, and 14 (P = .016). Ex vivo luciferase activity assay confirmed the presence of MSC-TF on days 8 and 14 after MI. Conclusion Multimodality reporter-gene imaging was successfully used to assess serial MSC survival after therapy for MI, and it was determined that the requisite preclinical imaging end point, 14 days of MSC survival, was met prior to a follow-up large-animal MSC study. (©) RSNA, 2016 Online supplemental material is available for this article.

Haemodynamic benefits of rapid deployment aortic valve replacement via a minimally invasive approach: 1-year results of a prospective multicentre randomized controlled trial.

OBJECTIVES: Aortic valve replacement (AVR) via minimally invasive surgery (MIS) may provide clinical benefits in patients with aortic valve disease. A new class of bioprosthetic valves that enable rapid deployment AVR (RDAVR) may facilitate MIS. We here report the 1-year results of a randomized, multicentre trial comparing the outcomes for MIS-RDAVR with those for conventional AVR via full sternotomy (FS) with a commercially available stented aortic bioprosthesis. METHODS: A total of 100 patients with aortic stenosis were enrolled in a prospective, multicentre, randomized comparison trial (CADENCE-MIS). Key exclusion criteria included AVR requiring concomitant procedures, ejection fraction of <25% and recent myocardial infarction or stroke. Patients were randomized to undergo MIS-RDAVR via upper hemisternotomy (EDWARDS INTUITY) or AVR via FS with a commercially available stented valve. Procedural, early and late clinical outcomes were assessed for both groups. Haemodynamic performance was evaluated by an echocardiography CoreLaboratory. RESULTS: Technical success was achieved in 94% of MIS-RDAVR patients. MIS-RDAVR was associated with significantly reduced cross-clamp times compared with FS (41.3 ± 20.3 vs 54.0 ± 20.3 min, P < 0.001). Clinical and functional outcomes were similar at 30 days and 1 year postoperatively for both groups. While both groups received a similarly sized implanted valve (22.9 ± 2.1 mm MIS-RDAVR vs 23.0 ± 2.1 mm FS-AVR; P = 0.91), MIS-RDAVR patients had significantly lower peak gradients 1 year postoperatively (16.9 ± 5.3 vs 21.9 ± 8.6 mmHg; P = 0.033) and a trend towards lower mean gradients (9.1 ± 2.9 vs 11.5 ± 4.3 mmHg; P = 0.082). In addition, MIS-RDAVR patients had a significantly larger effective orifice area 1 year postoperatively (1.9 ± 0.5 vs 1.7 ± 0.4 cm2; P = 0.047). Paravalvular leaks, however, were significantly more common in the MIS-RDAVR group (P = 0.027). CONCLUSIONS: MIS-RDAVR is associated with a significantly reduced cross-clamp time and better valvular haemodynamic function than FS-AVR. However, paravalvular leak rates are higher with MIS-RDAVR.

Porcine xenograft for aortic, mitral and double valve replacement: long-term results of 2544 consecutive patients.

OBJECTIVES: The aim of this study was to evaluate the results after stented porcine xenograft implantation with Linx™ anticalcification treatment in the aortic and/or mitral position in elderly patients. METHODS: Over a decade, a total of 2544 patients receiving aortic (AVR = 1920), mitral (MVR = 347) or double valve (DVR = 277) replacement (between November 2001 and March 2012) were evaluated. The study was designed on an 'all comers' basis including all patients with elective, urgent or emergent need for valve replacement. Outcome was assessed by reviewing the prospectively acquired hospital database as well as regular follow-up information obtained by annual written interviews. RESULTS: Mean patient age was 76.5 ± 6 (AVR), 73.8 ± 7 (MVR) and 74.2 ± 7 (DVR) years, respectively; 54.2%/41.9%/42.0% were male, and active endocarditis was diagnosed in 4.5%/19.9%/22.1%; indication for valve surgery and the logistic EUROSCORE I predicted risk for mortality was 15.4 ± 15%/19.9 ± 19%/22.3 ± 21%, respectively. Concomitant mitral valve repair was required in 196 (10.2%) (AVR) patients; coronary artery bypass graft surgery (CABG) in 840 (43.8%) (AVR), 82 (23.7%) (MVR) and 94 (34.1%) (DVR) patients; cryoablation in 232 (12.1%)/81 (23.4%)/67 (24.3%) patients and surgery on the thoracic aorta in 166 (8.7%)/12 (3.5%)/41 (14.9%) patients, respectively. The mean follow-up was 4.5 ± 3.5 years. The rate of freedom from endocarditis after 10 years was 98.3 ± 0.4%/97.5 ± 1.0%/97.4 ± 1.6% (P = n.s.). The rate of freedom from structural valve disease was 96.3 ± 0.6%/93.8 ± 2.4%/92.8 ± 2.2% (AVR versus DVR, P = 0.009), and from thromboembolic events was 94.8 ± 1.0%/91.5 ± 2.9%/97.9 ± 1.3%. The 30-day survival rate was 97.3 ± 0.4%/95.1 ± .1.2%/92.8 ± 1.6% and the 10-year survival rate was 42.1 ± 1.5%/33.9 ± 4.7%/22.1 ± 7.1%, respectively. CONCLUSIONS: The Epic™ stented porcine xenograft is associated with acceptable survival, with large proportions of patients free from valve-related complications and freedom from valve reintervention for all older, in-coming patients.

A simple and accurate method for computer-aided transapical aortic valve replacement.

BACKGROUND AND PURPOSE: Transapical aortic valve replacement (TAVR) is a recent minimally invasive surgical treatment technique for elderly and high-risk patients with severe aortic stenosis. In this paper, a simple and accurate image-based method is introduced to aid the intra-operative guidance of TAVR procedure under 2-D X-ray fluoroscopy. METHODS: The proposed method fuses a 3-D aortic mesh model and anatomical valve landmarks with live 2-D fluoroscopic images. The 3-D aortic mesh model and landmarks are reconstructed from interventional X-ray C-arm CT system, and a target area for valve implantation is automatically estimated using these aortic mesh models. Based on template-based tracking approach, the overlay of visualized 3-D aortic mesh model, landmarks and target area of implantation is updated onto fluoroscopic images by approximating the aortic root motion from a pigtail catheter motion without contrast agent. Also, a rigid intensity-based registration algorithm is used to track continuously the aortic root motion in the presence of contrast agent. Furthermore, a sensorless tracking of the aortic valve prosthesis is provided to guide the physician to perform the appropriate placement of prosthesis into the estimated target area of implantation. RESULTS: Retrospective experiments were carried out on fifteen patient datasets from the clinical routine of the TAVR. The maximum displacement errors were less than 2.0mm for both the dynamic overlay of aortic mesh models and image-based tracking of the prosthesis, and within the clinically accepted ranges. Moreover, high success rates of the proposed method were obtained above 91.0% for all tested patient datasets. CONCLUSION: The results showed that the proposed method for computer-aided TAVR is potentially a helpful tool for physicians by automatically defining the accurate placement position of the prosthesis during the surgical procedure.

Minimally invasive aortic valve replacement: the Leipzig experience.

BACKGROUND: Minimally invasive techniques are progressively challenging traditional approaches in cardiothoracic surgery. Minimally invasive aortic valve replacement (AVR) has become a routine procedure at our institution. METHODS: We retrospectively analyzed all patients undergoing minimally invasive isolated AVR between January 2003 and March 2014, at our institution. Mean follow-up was 4.7±4.3 years (range: 0-18 years) and was 99.8% complete. RESULTS: There were 1,714 patients who received an isolated minimally invasive AVR. The mean (± SD) patient age was 65±12.8 years, ejection fraction 60%±12% and log EuroSCORE 5.3%±5.1%. Mean cross-clamp time was 58±18 minutes and mean cardiopulmonary bypass (CPB) time was 82.9±26.7 minutes. Thirty-day survival was 97.8%±0.4%, and 69.4%±1.7% at 10-years. The multivariate analysis revealed age at surgery [P=0.016; odds ratio (OR), 1.1], length of surgery time (P=0.002; OR, 1.01), female gender (P=0.023; OR, 3.54), preoperative myocardial infarction (MI) (P=0.006; OR, 7.87), preoperative stroke (P=0.001; OR, 13.76) and preoperative liver failure (P=0.015; OR, 10.28) as independent risk factors for mortality. Cox-regression analysis revealed the following predictors for long term mortality: age over 75 years (P<0.001; OR, 3.5), preoperative dialysis (P<0.01; OR, 2.14), ejection fraction less than 30% (P=0.003; OR, 3.28) and urgent or emergency operation (P<0.001; OR, 2.3). CONCLUSIONS: Minimally invasive AVR can be performed safely and effectively with very few perioperative complications. The early and long-term outcomes in these patients are acceptable.

A randomized multicenter trial of minimally invasive rapid deployment versus conventional full sternotomy aortic valve replacement.

BACKGROUND: Minimally invasive surgical procedures (MIS) may offer several advantages over conventional full sternotomy (FS) aortic valve replacement (AVR). A novel class of aortic valve prostheses has been developed for rapid-deployment AVR (RDAVR). We report a randomized, multicenter trial comparing the outcomes for MIS-RDAVR with those of conventional FS-AVR. METHODS: A total of 100 patients with aortic stenosis were enrolled in a prospective, multicenter, randomized comparison trial (CADENCE-MIS). Exclusion criteria included ejection fraction below 25%, AVR requiring concomitant procedures, and recent myocardial infarction or stroke. Patients were randomized to undergo MIS-RDAVR through an upper hemisternotomy (n = 51) or AVR by FS with a conventional stented bioprosthesis (n = 49). Three patients were excluded before the procedure, and 3 more patients who were randomized to undergo RDAVR were excluded because of their anatomy. Procedural, early clinical outcomes, and functional outcomes were assessed for the remaining 94 patients. Hemodynamic performance was assessed by an echocardiography core laboratory. RESULTS: Implanted valve sizes were similar between groups (22.9 ± 2.1 vs 23.0 ± 2.1 mm, p = 0.9). MIS-RDAVR was associated with significantly reduced aortic cross-clamp times compared with FS-AVR (41.3 ± 20.3 vs 54.0 ± 20.3 minutes, p < 0.001), although cardiopulmonary bypass times were similar (68.8 ± 29.0 vs 74.4 ± 28.4 minutes, p = 0.21). Early clinical outcomes were similar between the two groups, including quality of life measures. The RDAVR patients had a significantly lower mean transvalvular gradient (8.5 vs 10.3 mm Hg, p = 0.044) and a lower prevalence of patient-prosthesis mismatch (0% vs 15.0%, p = 0.013) 3 months postoperatively compared with the FS-AVR patients. CONCLUSIONS: RDAVR by the MIS approach is associated with significantly reduced myocardial ischemic time and better valvular hemodynamic function than FS-AVR with a conventional stented bioprosthesis. Rapid deployment valves may facilitate the performance of MIS-AVR.

Enhanced caspase activity contributes to aortic wall remodeling and early aneurysm development in a murine model of Marfan syndrome.

OBJECTIVE: Rupture and dissection of aortic root aneurysms remain the leading causes of death in patients with the Marfan syndrome, a hereditary connective tissue disorder that affects 1 in 5000 individuals worldwide. In the present study, we use a Marfan mouse model (Fbn1(C1039G/+)) to investigate the biological importance of apoptosis during aneurysm development in Marfan syndrome. APPROACH AND RESULTS: Using in vivo single-photon emission computed tomographic-imaging and ex vivo autoradiography for Tc99m-annexin, we discovered increased apoptosis in the Fbn1(C1039G/+) ascending aorta during early aneurysm development peaking at 4 weeks. Immunofluorescence colocalization studies identified smooth muscle cells (SMCs) as the apoptotic cell population. As biological proof of concept that early aortic wall apoptosis plays a role in aneurysm development in Marfan syndrome, Fbn1(C1039G/+) mice were treated daily from 2 to 6 weeks with either (1) a pan-caspase inhibitor, Q-VD-OPh (20 mg/kg), or (2) vehicle control intraperitoneally. Q-VD-OPh treatment led to a significant reduction in aneurysm size and decreased extracellular matrix degradation in the aortic wall compared with control mice. In vitro studies using Fbn1(C1039G/+) ascending SMCs showed that apoptotic SMCs have increased elastolytic potential compared with viable cells, mostly because of caspase activity. Moreover, in vitro (1) cell membrane isolation, (2) immunofluorescence staining, and (3) scanning electron microscopy studies illustrate that caspases are expressed on the exterior cell surface of apoptotic SMCs. CONCLUSIONS: Caspase inhibition attenuates aneurysm development in an Fbn1(C1039G/+) Marfan mouse model. Mechanistically, during apoptosis, caspases are expressed on the cell surface of SMCs and likely contribute to elastin degradation and aneurysm development in Marfan syndrome.

Minimal invasive aortic valve replacement surgery is associated with improved survival: a propensity-matched comparison.

OBJECTIVES: To compare early and long-term outcomes of minimally invasive surgery (MIS) versus full sternotomy (FS) isolated aortic valve replacement (AVR). METHODS: We retrospectively analysed all patients who underwent isolated bioprosthetic AVR between 2003 and March 2012 at our institution. Matching was performed based on a propensity score, which was obtained using the output of a logistic regression on relevant preoperative risk factors. Mean follow-up was 3.1±2.7 years (range 0-9.0 years) and was 99.8% complete. RESULTS: A total of 2051 patients (FS, 1572; MIS, 479) underwent isolated bioprosthetic AVR during the study period. MIS patients were significantly younger (67.8±11.2 vs 70.4±9.4 years) and had a lower logistic EuroSCORE (6.6±6.4 vs 11.2±13.4%, both P<0.001). Propensity matching resulted in 477 matched patients from each group, with no significant differences in any of the preoperative variables. Aortic cross-clamp times were significantly longer in MIS patients (59.4±16.0 vs 56.9±14.6 min, P=0.008). Nonetheless, MIS AVR was associated with a significantly lower incidence of intra-aortic balloon pump usage (0.4 vs 2.1%, P=0.042) and in-hospital mortality (0.4 vs 2.3%, P=0.013), while FS patients had a lower rate of re-exploration for bleeding (1.5 vs 4.2%, P=0.019). Five- and 8-year survival post-AVR was significantly higher in MIS patients (89.3±2.4% and 77.7±4.7% vs 81.8±2.2% and 72.8±3.1%, respectively, P=0.034). Cox regression analysis revealed MIS (hazard ratio: 0.47, 95% confidence interval: 0.26-0.87) as an independent predictor of long-term survival. CONCLUSION: MIS AVR is associated with very good early and long-term survival, despite longer myocardial ischaemic times. MIS AVR can be performed safely with results that are at least equivalent to those achieved through an FS.

Bilateral versus single lung transplant for idiopathic pulmonary fibrosis.

OBJECTIVES: It is unknown if uni- or bilateral lung transplant is best for treatment of usual idiopathic pulmonary fibrosis. We reviewed our single-center experience comparing both treatments. MATERIALS AND METHODS: Between 2002 and 2011, one hundred thirty-eight patients at our institution underwent a lung transplant. Of these, 58 patients presented with idiopathic pulmonary fibrosis (56.9%) and were the focus of this study. RESULTS: Thirty-nine patients received a single lung transplant and 19 patients a bilateral sequential lung transplant. The mean patient age was 54 ± 10 years, and 69% were male. The intraoperative course was uneventful, save for 7 patients who needed extracorporeal membrane oxygenation support. Three patients had respiratory failure before the lung transplant that required mechanical ventilation and was supported by extracorporeal membrane oxygenation. Elevated pulmonary artery pressure > 40 mm Hg was identified as an independent predictor of early mortality by uni- and multivariate analysis (P = .01; OR 9.7). Using a Cox regression analysis, postoperative extracorporeal membrane oxyge-nation therapy (P = .01; OR 10.2) and the need for > 10 red blood cell concentrate during the first 72 hours after lung transplant (P = .01; OR 5.6) were independent predictors of long-term survival. Actuarial survival at 1 and 5 years was 65.6% and 55.3%, with no significant between-group differences (70.6% and 54.3%). CONCLUSIONS: Lung transplant is a safe and curative treatment for idiopathic pulmonary fibrosis. According to our results, unilateral lung transplant for idiopathic pulmonary fibrosis is an alternative to bilateral lung transplant and may affect the allocation process.

Tirone David procedure for bicuspid aortic valve disease: impact of root geometry and valve type on mid-term outcomes.

OBJECTIVES: A 180/180° configuration has been reported to increase repair durability after valve-sparing aortic root replacement (V-SARR) for bicuspid aortic valve (BAV) disease. We studied the impact of commissural angular configuration (CAC) and of BAV type on valve performance after V-SARR. METHODS: A total of 85 BAV patients (68 males, age 44 ± 11 years) underwent Tirone David-V V-SARR between 1997 and 2013. BAV type was documented intraoperatively, and CAC determined from pre- and postoperative computed tomography scans as the angle subtended by the non-fused cusp. Transthoracic echocardiogram was performed at 6 ± 3 days and at 2.9 ± 2.1 years. Functional end-points included freedom from aortic regurgitation (AR) 1+, AR 2+ and freedom from AR progression (0 to 1+, or 1+ to 2+). Tested variables included preoperative CAC (>160 vs <160°) and changes in CAC after V-SARR (Δ > 30° vs Δ < 30°) and Sievers' BAV type (SØ or S1). RESULTS: CAC in SØ-BAV (n = 26) changed minimally from 164 ± 12 to 171 ± 11° (mean Δ = 7.2 ± 16°, P = 0.044), whereas in S1-BAV (n = 59) CAC changed substantially from 132 ± 19 to 156 ± 18° (mean Δ = 27 ± 21°, P < 0.001). Larger postoperative CAC angles were not linked to better mid-term valve performance, but Sievers' BAV type had a major effect on valve performance: mild AR in S1/i BAV progressed more often (76 vs 32% at 4 years, P = 0.017) and 1+ AR was more frequent (70 vs 36% at 4 years, P = 0.008) compared with SØ-BAV. CONCLUSIONS: BAV type, including number of raphes, sinuses and commissures (SØ superior to S1) but not commissure geometry within the neoroot alone, appears to be linked to functional outcomes after V-SARR for BAV.

Mitral valve pathology in severely impaired left ventricles can be successfully managed using a right-sided minimally invasive surgical approach.

OBJECTIVES: We sought to review our experience in patients with severely impaired left ventricular function (ejection fraction (EF) ≤ 30%) who underwent minimally invasive mitral valve (MV) surgery (Mini-MV). METHODS: Between 1999 and 2010, a total of 3450 patients underwent Mini-MV surgery at our institution. Of these, 177 had severely impaired left ventricular function (EF < 30%, including ischaemic and non-ischaemic cardiomyopathy). Primary indication for surgery was MV regurgitation in all but 5 patients (2.8%), who were diagnosed with mixed regurgitation and stenosis. Mean age of patients was 67 ± 11 years and 110 were male (62.1%). Mean EuroSCORE predicted risk of mortality was 14.7 ± 13.6%. RESULTS: MV repair was accomplished in 86.4% of patients (n = 153), and MV replacement was performed in 13.6% (n = 24). Primary MV repair included implantation of a rigid annuloplasty ring (mean size 29.5 ± 2.2 mm) in 95.4% of patients, and additional MV procedures as required. Concomitant procedures consisted of tricuspid valve surgery in 15.3% of patients, atrial fibrillation ablation in 27.1% and atrial septal defect/persistent foramen ovale closure in 5.6%. The duration of cardiopulmonary bypass was 123 ± 64 min and aortic cross-clamp time was 67 ± 27 min. Thirty-day mortality was 7.9%. The mean follow-up time was 3 ± 2.5 years, and the follow-up was 94.0% complete. Ten-year survival was 45.5% (95% CI: 35.2-55.9) for the overall group. The rate of MV-related reintervention was 4%, while heart transplantation was performed in 6%. CONCLUSIONS: Mini-MV surgery in patients with significantly impaired left ventricular function can be performed with a reasonable operative mortality and acceptable long-term survival for this high-risk patient cohort.

Predictors of permanent pacemaker implantation after Medtronic CoreValve bioprosthesis implantation.

AIMS: High-grade conduction disturbances requiring permanent pacemaker (PPM) implantation occur in up to 40% of patients following transcatheter aortic valve implantation (TAVI). The aim of this study was to identify pre-operative risk factors for PPM implantation after TAVI with the Medtronic CoreValve prosthesis (CVP). METHODS AND RESULTS: We retrospectively analysed 109 patients following transfemoral CVP implantation performed between 2008 and 2009 at the Leipzig Heart Center. Patients who had indwelling PPM at the time of TAVI (n = 21) were excluded, leaving 88 patients for analysis. Mean age was 80.3 ± 6.6 years and logistic EuroScore predicted risk of mortality was 23.3 ± 12.1%. A total of 32 patients (36%) underwent PPM implantation post-TAVI during the same hospital admission. A total of 27/88 (31%) had evidence of pre-operative abnormal conduction, including first degree AV block and left bundle brunch block. Statistically significant risk factors for the need for post-operative PPM were patient age >75 years [P = 0.02, odds ratio (OR) 4.6], pre-operative heart rate <65 beats per minute (b.p.m.; P = 0.04, OR 2.9), CVP oversizing >4 mm (P = 0.03, OR 2.8), CVP prosthesis >26 mm (OR 2.2), atrial fibrillation (P = 0.001, OR 5.2), and ventricular rate <65 b.p.m. at the first post-operative day (P = 0.137, OR 6.0). CONCLUSION: PPM implantation occurs frequently after transfemoral TAVI with the CVP. Older age, chronic atrial fibrillation, pre-operative bradycardia, and larger or significantly oversized prostheses were independent risk factors for PPM implantation following TAVI with the CVP.

Potential role of γδ T cell-derived IL-17 in acute cardiac allograft rejection.

BACKGROUND: Although αß T cells are known to participate in the development of acute cardiac allograft rejection, the role of γδ T cells remains poorly understood. We hypothesized that γδ T cells contribute to acute allograft rejection thru interleukin (IL)-17 production. METHODS: Donor hearts from FVB mice (H-2q) were heterotopically transplanted into C57BL/6-wild type (WT) and γδ T cell-deficient (TCRδ-/-) recipient mice (H-2b). Overall graft survival was monitored. Graft infiltrating cell profile, including γδ T cell subtype, cytokine expression, and myeloperoxidase activity were measured by flow cytometry, TaqMan (Applied Biosystems, Carlsbad, CA) polymerase chain reaction, and myeloperoxidase assay, respectively, on postoperative days 3 and 6. RESULTS: Graft survival was prolonged in TCRδ-/- recipients compared with WT controls. Graft infiltrating cells, including CD45+, CD4+, CD8+, and Gr1+ cells were significantly decreased in TCRδ-/- recipients compared with WT. Donor hearts transplanted into TCRδ-/- recipients had reduced IL-17 and IL-6 messenger RNA expression. Corroborating the gene expression, intracellular cytokine staining showed decreased IL-17 producing cells in TCRδ-/- recipients. Finally, Vγ1+ and Vγ4+ T cells did not produce IL-17, although both represent 20% to 30% total graft infiltrating γδ T cells. CONCLUSIONS: The γδ T cells promote acute cardiac allograft rejection, presumably by producing IL-17. The γδ T cell depletion may prove beneficial in prolonging allograft survival by suppressing IL-17 production.

MicroRNA-21 blocks abdominal aortic aneurysm development and nicotine-augmented expansion.

Identification and treatment of abdominal aortic aneurysm (AAA) remains among the most prominent challenges in vascular medicine. MicroRNAs are crucial regulators of cardiovascular pathology and represent possible targets for the inhibition of AAA expansion. We identified microRNA-21 (miR-21) as a key modulator of proliferation and apoptosis of vascular wall smooth muscle cells during development of AAA in two established murine models. In both models (AAA induced by porcine pancreatic elastase or infusion of angiotensin II), miR-21 expression increased as AAA developed. Lentiviral overexpression of miR-21 induced cell proliferation and decreased apoptosis in the aortic wall, with protective effects on aneurysm expansion. miR-21 overexpression substantially decreased expression of the phosphatase and tensin homolog (PTEN) protein, leading to increased phosphorylation and activation of AKT, a component of a pro-proliferative and antiapoptotic pathway. Systemic injection of a locked nucleic acid-modified antagomir targeting miR-21 diminished the pro-proliferative impact of down-regulated PTEN, leading to a marked increase in the size of AAA. Similar results were seen in mice with AAA augmented by nicotine and in human aortic tissue samples from patients undergoing surgical repair of AAA (with more pronounced effects observed in smokers). Modulation of miR-21 expression shows potential as a new therapeutic option to limit AAA expansion and vascular disease progression.

Inhibition of microRNA-29b reduces murine abdominal aortic aneurysm development.

MicroRNAs (miRs) regulate gene expression at the posttranscriptional level and play crucial roles in vascular integrity. As such, they may have a role in modifying abdominal aortic aneurysm (AAA) expansion, the pathophysiological mechanisms of which remain incompletely explored. Here, we investigate the role of miRs in 2 murine models of experimental AAA: the porcine pancreatic elastase (PPE) infusion model in C57BL/6 mice and the AngII infusion model in Apoe-/- mice. AAA development was accompanied by decreased aortic expression of miR-29b, along with increased expression of known miR-29b targets, Col1a1, Col3a1, Col5a1, and Eln, in both models. In vivo administration of locked nucleic acid anti-miR-29b greatly increased collagen expression, leading to an early fibrotic response in the abdominal aortic wall and resulting in a significant reduction in AAA progression over time in both models. In contrast, overexpression of miR-29b using a lentiviral vector led to augmented AAA expansion and significant increase of aortic rupture rate. Cell culture studies identified aortic fibroblasts as the likely vascular cell type mediating the profibrotic effects of miR-29b modulation. A similar pattern of reduced miR-29b expression and increased target gene expression was observed in human AAA tissue samples compared with that in organ donor controls. These data suggest that therapeutic manipulation of miR-29b and its target genes holds promise for limiting AAA disease progression and protecting from rupture.