Balloon predilation or direct valve implantation in TAVI for women: Insights from the DIRECTAVI study.

BACKGROUND: The randomized DIRECTAVI trial demonstrated safety and feasibility of transcatheter aortic valve implantation (TAVI) without balloon aortic valvuloplasty (BAV) using SAPIEN 3 balloon-expandable devices. However, the female population with smaller anatomy may have potential higher risk of residual gradient and/or mismatch. PURPOSE: We assessed the impact of BAV on the procedural success rate and clinical outcomes in the female population of the DIRECTAVI trial. METHODS: Between May 2016 and May 2018, 91 of the 250 patients included in the DIRECTAVI trial were women (38.6%), 45 of them (49.5%) were enrolled in the BAV group and 46 of them (50.5%) in the direct TAVI group. The primary endpoint was procedural success rate in women (Valve Academic Research Consortium-2 criteria). The secondary endpoint included evaluation of PPM and 1-month major adverse events according to the implantation stategy in women and comparison between men and women regarding major endpoints. RESULTS: The primary endpoint occurred in 29 women (64.4%) in the BAV group and in 34 women (73.9%) in the direct TAVI group (mean difference 9.47%; 95% confidence interval: 6.5%-25.4%; p = 0.045 for non-inferiority of the direct strategy). One-month major adverse events were similar between the 2 women groups. Procedural success was lower in women vs men (p = 0.01) due to higher incidence of moderate mismatches in women (p = 0.001) but with no significant difference regarding the implantation strategy (p = 0.4). CONCLUSION: Direct implantation of the balloon-expandable SAPIEN 3 valve was non-inferior to predilatation on procedural success in women. Incidence of moderate mismatch was higher in women but was not related to the implantation strategy.

Long-term follow-up of balloon-expandable valves according to the implantation strategy: insight from the DIRECTAVI trial.

BACKGROUND: Safety and feasibility of transcatheter aortic valve replacement (TAVR) without balloon aortic valvuloplasty (BAV) using the SAPIEN 3 balloon-expandable device has been previously demonstrated. The impact on long-term valve hemodynamic performances and outcomes remains however unknown. We evaluate long-term clinical and hemodynamic results according to the implant strategy (direct TAVR vs BAV pre-TAVR) in patients included in the DIRECTAVI randomized trial (NCT02729519). METHODS: Clinical and echocardiographic follow-up until January 2023 was performed for all patients included in the DIRECTAVI trial since 2016 (n = 228). The primary endpoint was incidence of moderate/severe hemodynamic valve deterioration (HVD), according to the Valve Academic Research defined Consortium-3 criteria (increase in mean gradient ≥10 mmHg resulting in a final mean gradient ≥20 mmHg, or new/worsening aortic regurgitation of 1 grade resulting in ≥ moderate aortic regurgitation). RESULTS: Median follow-up was 3.8 (2.2-4.7) years. Mean age at follow-up was 87 ± 6.7 years. No difference in incidence of HVD in the direct implantation group compared to the BAV group was found (incidence of 1.97 per 100 person-years and 1.45 per 100 person-years, respectively, P = 0.6). Prevalence of predicted prothesis-patient mismatch was low (n = 13 [11.4%] in the direct TAVR group vs n = 15 [13.2%] in BAV group) and similar between both groups (P = .7). Major outcomes including death, stroke, hospitalization for heart failure and pacemaker implantation were similar between both groups, (P = .4, P = .7, P = .3, and P = .3 respectively). CONCLUSION: Direct implantation of the balloon-expandable device in TAVR was not associated with an increased risk of moderate/severe HVD or major outcomes up to 6-year follow-up. These results guarantee wide use of direct balloon-expandable valve implantation, when feasible. CLINICAL TRIALS REGISTRATION NUMBER: NCT05140317.

Identification of Low- versus High-Risk Acute Coronary Syndrome for a Selective ECG Monitoring Strategy.

BACKGROUND: While admission of patients with acute coronary syndromes (ACS) in cardiology intensive care unit (CICU) is usual, in-hospital major outcomes in lower risk patients may be evaluated after early coronary angiography according to the European guidelines. METHODS: Consecutive ACS patients were prospectively included after coronary angiography evaluation within 24 h and percutaneous coronary intervention (PCI), when required. Patients were classified as high- or low-risk according to hemodynamics, rhythmic state, ischemic and bleeding risks. Major in-hospital outcomes were assessed. RESULTS: From January to June 2021, 277 patients were enrolled (62.8% with ST-segment elevation myocardial infarction (STEMI) (n = 174); 37.2% with non-NSTEMI (NSTEMI) (n = 103). PCI was required for 260 patients (93.9%). Seventy-four patients (26.7%) were classified as low-risk (n = 47 NSTEMI; n= 27 STEMI) and 203 patients (73.3%) as high-risk of events. All patients were monitored in CICU. While 38 patients (18.7%) from the high-risk group reached the primary endpoint, mainly related to rhythmic or conduction disorder (n = 24, 11.8%) or unstable hemodynamics (n = 17; 8.4%), only 1 patient (1.3%) in the low-risk group had one major outcome (no fatal bleeding); p < 0.01. The negative predictive value of our patient stratification for the absence of major in-hospital outcome was 100% (CI95%: 100-100%) for STEMI and 97.9% [CI95%: 93.2-100%] for NSTEMI patients. CONCLUSIONS: Stratification of ACS patients after early coronary angiography and most of the time PCI, identify a population with very low risk of in-hospital events (1/4 of all ACS and 1/2 of NSTEMI) who may probably not require ECG monitoring and/or CICU admission. (NCT04378504).

Barriers and Facilitators to the Use of Clinical Decision Support Systems in Primary Care: A Mixed-Methods Systematic Review.

PURPOSE: To identify and quantify the barriers and facilitators to the use of clinical decision support systems (CDSSs) by primary care professionals (PCPs). METHODS: A mixed-methods systematic review was conducted using a sequential synthesis design. PubMed/MEDLINE, PsycInfo, Embase, CINAHL, and the Cochrane library were searched in July 2021. Studies that evaluated CDSSs providing recommendations to PCPs and intended for use during a consultation were included. We excluded CDSSs used only by patients, described as concepts or prototypes, used with simulated cases, and decision supports not considered as CDSSs. A framework synthesis was performed according to the HOT-fit framework (Human, Organizational, Technology, Net Benefits), then a quantitative synthesis evaluated the impact of the HOT-fit categories on CDSS use. RESULTS: A total of 48 studies evaluating 45 CDSSs were included, and 186 main barriers or facilitators were identified. Qualitatively, barriers and facilitators were classified as human (eg, perceived usefulness), organizational (eg, disruption of usual workflow), and technological (eg, CDSS user-friendliness), with explanatory elements. The greatest barrier to using CDSSs was an increased workload. Quantitatively, the human and organizational factors had negative impacts on CDSS use, whereas the technological factor had a neutral impact and the net benefits dimension a positive impact. CONCLUSIONS: Our findings emphasize the need for CDSS developers to better address human and organizational issues, in addition to technological challenges. We inferred core CDSS features covering these 3 factors, expected to improve their usability in primary care.

Muscle regeneration affects Adeno Associated Virus 1 mediated transgene transcription.

Duchenne muscular dystrophy is a severe neuromuscular disease causing a progressive muscle wasting due to mutations in the DMD gene that lead to the absence of dystrophin protein. Adeno-associated virus (AAV)-based therapies aiming to restore dystrophin in muscles, by either exon skipping or microdystrophin expression, are very promising. However, the absence of dystrophin induces cellular perturbations that hinder AAV therapy efficiency. We focused here on the impact of the necrosis-regeneration process leading to nuclear centralization in myofiber, a common feature of human myopathies, on AAV transduction efficiency. We generated centronucleated myofibers by cardiotoxin injection in wild-type muscles prior to AAV injection. Intramuscular injections of AAV1 vectors show that transgene expression was drastically reduced in regenerated muscles, even when the AAV injection occurred 10 months post-regeneration. We show also that AAV genomes were not lost from cardiotoxin regenerated muscle and were properly localised in the myofiber nuclei but were less transcribed leading to muscle transduction defect. A similar defect was observed in muscles of the DMD mouse model mdx. Therefore, the regeneration process per se could participate to the AAV-mediated transduction defect observed in dystrophic muscles which may limit AAV-based therapies.

Simplified TAVR Procedure: How Far Is It Possible to Go?

Increasing operators' experience and improvement of the technique have resulted in a drastic reduction in complications following transcatheter aortic valve replacement (TAVR) in patients with lower surgical risk. In parallel, the procedure was considerably simplified, with a routine default approach including local anesthesia in the catheterization laboratory, percutaneous femoral approach, radial artery as the secondary access, prosthesis implantation without predilatation, left ventricle wire pacing and early discharge. Thus, the "simplified" TAVR adopted in most centers nowadays is a real revolution of the technique. However, simplified TAVR must be accompanied upstream by a rigorous selection of patients who can benefit from a minimalist procedure in order to guarantee its safety. The minimalist strategy must not become dogmatic and careful pre-, per- and post-procedural evaluation of patients with well-defined protocols guarantee optimal care following TAVR. This review aims to evaluate the benefits and limits of the simplified TAVR procedure in a current and future vision.

Acute Coronary Syndrome in the Era of SARS-CoV-2 Infection: A Registry of the French Group of Acute Cardiac Care.

BACKGROUND: In this study, we aimed to report clinical characteristics and outcomes of patients with and without SARS-CoV-2 infection who were referred for acute coronary syndrome (ACS) during the peak of the pandemic in France. METHODS: We included all consecutive patients referred for ST-elevation myocardial infarction (STEMI) or non-STEMI (NSTEMI) during the first 3 weeks of April 2020 in 5 university hospitals (Paris, south, and north of France), all performing primary percutaneous coronary intervention. RESULTS: The study included 237 patients (67 ± 14 years old; 69% male), 116 (49%) with STEMI and 121 (51%) with NSTEMI. The prevalence of SARS-CoV-2-associated ACS was 11% (n = 26) and 11 patients had severe hypoxemia on presentation (mechanical ventilation or nasal oxygen > 6 L/min). Patients were comparable regarding medical history and risk factors, except a higher prevalence of diabetes mellitus in SARS-CoV-2 patients (53.8% vs 25.6%; P = 0.003). In SARS-CoV-2 patients, cardiac arrest on admission was more frequent (26.9% vs 6.6%; P < 0.001). The presence of significant coronary artery disease and culprit artery occlusion in SARS-CoV-2 patients respectively, was 92% and 69.4% for those with STEMI, and 50% and 15.5% for those with NSTEMI. Percutaneous coronary intervention was performed in the same percentage of STEMI (84.6%) and NSTEMI (84.8%) patients, regardless of SARS-CoV-2 infection, but no-reflow (19.2% vs 3.3%; P < 0.001) was greater in SARS-CoV-2 patients. In-hospital death occurred in 7 SARS-CoV-2 patients (5 from cardiac cause) and was higher compared with noninfected patients (26.9% vs 6.2%; P < 0.001). CONCLUSIONS: In this registry, ACS in SARS-CoV-2 patients presented with high a percentage of cardiac arrest on admission, high incidence of no-reflow, and high in-hospital mortality.

CONTEXTE: Notre étude avait pour but d'établir les caractéristiques cliniques et les résultats de patients infectés ou non par le SRAS-CoV-2 qui ont été orientés en raison d'un syndrome coronarien aigu (SCA) pendant la phase aiguë de la pandémie en France. MÉTHODOLOGIE: Nous avons inclus dans l'étude tous les patients consécutifs qui ont présenté un infarctus du myocarde avec sus-décalage du segment ST (STEMI) ou sans sus-décalage du segment ST (NSTEMI) au cours des 3 premières semaines d'avril 2020 et qui ont été orientés vers 5 hôpitaux universitaires (situés à Paris, ainsi que dans le sud et le nord de la France), tous en mesure de réaliser des interventions co-ronariennes percutanées primaires. RÉSULTATS: L'étude comprenait 237 patients (âge : 67 ± 14 ans; proportion d'hommes : 69 %); 116 (49 %) présentaient un STEMI et 121 (51 %), un NSTEMI. La prévalence d'un SCA associé à une infection par le SRAS-CoV-2 s'établissait à 11 % (n = 26), et 11 patients étaient en hypoxémie grave (nécessitant une ventilation artificielle ou l'administration d'oxygène par voie nasale à un débit de plus de 6 l/min) à leur arrivée. Les patients présentaient des antécédents médicaux et des facteurs de risque comparables, à l'exception du fait que la prévalence du diabète était plus élevée chez les patients infectés par le SRAS-CoV-2 (53,8 % vs 25,6 %; p = 0,003). Ces derniers avaient plus souvent subi un arrêt cardiaque à leur admission (26,9 % vs 6,6 %; p < 0,001). Chez les patients infectés par le SRAS-CoV-2, une coronaropathie importante et une occlusion de l'artère coupable ont été observées chez respectivement 92 % et 69,4 % des patients présentant un STEMI, et chez 50 % et 15,5 % des patients présentant un NSTEMI. Une intervention coronarienne percutanée a été effectuée dans les mêmes proportions chez les patients subissant un STEMI (84,6 %) que chez ceux présentant un NSTEMI (84,8 %), sans égard à la présence ou à l'absence d'une infection par le SRAS-CoV-2, mais les cas de non-reperfusion (no-reflow) ont été plus fréquents chez les patients infectés que chez les autres patients (19,2 % et 3,3 %, respectivement; p < 0,001). Sept patients infectés par le SRAS-CoV-2 sont morts à l'hôpital (5 de cause cardiaque), ce qui représente un taux de mortalité plus élevé que chez les patients non infectés (26,9 % vs 6,2 %; p < 0,001). CONCLUSIONS: Dans le cadre de cette étude, le SCA survenu chez les patients infectés par le SRAS-CoV-2 était associé à un fort pourcentage d'arrêt cardiaque à l'admission, à une fréquence élevée de cas de non-reperfusion et à un taux élevé de mortalité hospitalière.

Oritatami: A Computational Model for Molecular Co-Transcriptional Folding.

We introduce and study the computational power of Oritatami, a theoretical model that explores greedy molecular folding, whereby a molecular strand begins to fold before its production is complete. This model is inspired by our recent experimental work demonstrating the construction of shapes at the nanoscale from RNA, where strands of RNA fold into programmable shapes during their transcription from an engineered sequence of synthetic DNA. In the model of Oritatami, we explore the process of folding a single-strand bit by bit in such a way that the final fold emerges as a space-time diagram of computation. One major requirement in order to compute within this model is the ability to program a single sequence to fold into different shapes dependent on the state of the surrounding inputs. Another challenge is to embed all of the computing components within a contiguous strand, and in such a way that different fold patterns of the same strand perform different functions of computation. Here, we introduce general design techniques to solve these challenges in the Oritatami model. Our main result in this direction is the demonstration of a periodic Oritatami system that folds upon itself algorithmically into a prescribed set of shapes, depending on its current local environment, and whose final folding displays the sequence of binary integers from 0 to N = 2 k - 1 with a seed of size O ( k ) . We prove that designing Oritatami is NP-hard in the number of possible local environments for the folding. Nevertheless, we provide an efficient algorithm, linear in the length of the sequence, that solves the Oritatami design problem when the number of local environments is a small fixed constant. This shows that this problem is in fact fixed parameter tractable (FPT) and can thus be solved in practice efficiently. We hope that the numerous structural strategies employed in Oritatami enabling computation will inspire new architectures for computing in RNA that take advantage of the rapid kinetic-folding of RNA.

Bone histomorphometry of transiliac paired bone biopsies after 6 or 12 months of treatment with oral strontium ranelate in 387 osteoporotic women: randomized comparison to alendronate.

Preclinical studies indicate that strontium ranelate (SrRan) induces opposite effects on bone osteoblasts and osteoclasts, suggesting that SrRan may have a dual action on both formation and resorption. By contrast, alendronate (ALN) is a potent antiresorptive agent. In this multicenter, international, double-blind, controlled study conducted in 387 postmenopausal women with osteoporosis, transiliac bone biopsies were performed at baseline and after 6 or 12 months of treatment with either SrRan 2 g per day (n = 256) or alendronate 70 mg per week (n = 131). No deleterious effect on mineralization of SrRan or ALN was observed. In the intention-to-treat (ITT) population (268 patients with paired biopsy specimens), changes in static and dynamic bone formation parameters were always significantly higher with ALN compared with SrRan at month 6 (M6) and month 12 (M12). Static parameters of formation were maintained between baseline and the last value with SrRan, except for osteoblast surfaces, which decreased at M6. Significant decreases in the dynamic parameters of formation (mineralizing surface, bone formation rate, adjusted apposition rate, activation frequency) were noted at M6 and M12 in SrRan. Compared with ALN, the bone formation parameters at M6 and M12 were always significantly higher (p < 0.001) with SrRan. ALN, but not SrRan, decreased resorption parameters. Compared with the baseline paired biopsy specimens, wall thickness was significantly decreased at M6 but not at M12 and cancellous bone structure parameters (trabecular bone volume, trabecular thickness, trabecular number, number of nodes/tissue volume) were significantly decreased at M12 with SrRan; none of these changes were significantly different from ALN. In conclusion, this large controlled paired biopsy study over 1 year shows that the bone formation remains higher with a lower diminution of the bone remodeling with SrRan versus ALN. From these results, SrRan did not show a significant anabolic action on bone remodeling.

A pooled analysis of vitamin D dose requirements for fracture prevention.

BACKGROUND: The results of meta-analyses examining the relationship between vitamin D supplementation and fracture reduction have been inconsistent. METHODS: We pooled participant-level data from 11 double-blind, randomized, controlled trials of oral vitamin D supplementation (daily, weekly, or every 4 months), with or without calcium, as compared with placebo or calcium alone in persons 65 years of age or older. Primary end points were the incidence of hip and any nonvertebral fractures according to Cox regression analyses, with adjustment for age group, sex, type of dwelling, and study. Our primary aim was to compare data from quartiles of actual intake of vitamin D (including each individual participant's adherence to the treatment and supplement use outside the study protocol) in the treatment groups of all trials with data from the control groups. RESULTS: We included 31,022 persons (mean age, 76 years; 91% women) with 1111 incident hip fractures and 3770 nonvertebral fractures. Participants who were randomly assigned to receive vitamin D, as compared with those assigned to control groups, had a nonsignificant 10% reduction in the risk of hip fracture (hazard ratio, 0.90; 95% confidence interval [CI], 0.80 to 1.01) and a 7% reduction in the risk of nonvertebral fracture (hazard ratio, 0.93; 95% CI, 0.87 to 0.99). By quartiles of actual intake, reduction in the risk of fracture was shown only at the highest intake level (median, 800 IU daily; range, 792 to 2000), with a 30% reduction in the risk of hip fracture (hazard ratio, 0.70; 95% CI, 0.58 to 0.86) and a 14% reduction in the risk of any nonvertebral fracture (hazard ratio, 0.86; 95% CI, 0.76 to 0.96). Benefits at the highest level of vitamin D intake were fairly consistent across subgroups defined by age group, type of dwelling, baseline 25-hydroxyvitamin D level, and additional calcium intake. CONCLUSIONS: High-dose vitamin D supplementation (≥800 IU daily) was somewhat favorable in the prevention of hip fracture and any nonvertebral fracture in persons 65 years of age or older. (Funded by the Swiss National Foundations and others.).

Distribution of strontium and mineralization in iliac bone biopsies from osteoporotic women treated long-term with strontium ranelate.

OBJECTIVE: To investigate interactions between strontium (Sr) and bone mineral and its effects on mineralization in osteoporotic women treated long-term with Sr ranelate (SrRan). DESIGN: In this study, 34 iliac bone biopsies were analyzed after 2, 12, 24, 36, 48, and 60 months of treatment with SrRan. METHODS: Sr global distribution was analyzed by X-ray cartography and the percentage of bone area containing Sr was calculated in the bone samples. The focal distribution of Sr in all bone samples was investigated by X-ray microanalysis. The degree of mineralization was assessed by quantitative microradiography. RESULTS: Absent from old bone formed before the beginning of treatment, Sr was exclusively present in bone formed during this treatment with a much higher focal Sr content in new bone structural units than in old ones. A progressive increase in the extent of areas containing Sr was observed during treatment. The focal bone Sr content in recently formed bone was constant over treatment. Secondary mineralization was maintained at a normal level during treatment. CONCLUSION: Thus, the quality of bone mineralization (density and heterogeneity at tissue level) was preserved after a long-term treatment with SrRan.

Time sequence of secondary mineralization and microhardness in cortical and cancellous bone from ewes.

Bone mineral is a major determinant of the mechanical resistance of bones. In bone structural units (BSUs), mineralization of osteoid tissue begins with a rapid primary mineralization followed by a secondary mineralization phase, i.e., a slow and gradual maturation of the mineral component leading to complete mineralization during an unknown period. The aim of this study was to determine the chronology of secondary bone mineralization in ewes, an animal model with a remodeling activity close to humans. Eighteen ewes received different fluorescent labels every 6 months to date the "age" of each labeled BSU. The degree of mineralization of bone (DMB) and Vickers microhardness were measured in labeled BSUs, while mineralization at the crystal level was assessed by Fourier transform infrared microspectroscopy (FTIRM). During the first 6 months of mineralization, degree of mineralization and microhardness significantly increased. They then increased more slowly until at 30 months they reach their maximal values. This progression during secondary mineralization was associated with an improvement of both the maturation and the crystal perfection of the mineral part of bone matrix. Finally, secondary mineralization in BSUs is completed after a period of 30 months. This observation should be taken into account for understanding the effects of long-term treatments of bone diseases.

Mesalamine foam enema versus mesalamine liquid enema in active left-sided ulcerative colitis.

AIM: To determine in a noninferiority study whether mesalamine foam is as effective as mesalamine liquid enema for inducing clinical remission in patients with active left-sided ulcerative colitis (UC). METHODS: In a multicenter investigator-blind trial, 375 patients with mild-to-moderate UC were randomized to receive mesalamine foam 1 g/80 mL/day or mesalamine liquid enema 1 g/100 mL/day for 4 wk (W). Inclusion criteria were: disease extension at least 5 cm from anorectal junction and not above splenic flexure and Clinical Activity Index (CAI) 1-4 > or = 4. Primary end point was clinical remission at W4 defined as a CAI 1-4 < or = 2. Noninferiority of the foam to liquid enema was declared if the lower limit of the 97.5% unilateral confidence interval (97.5% CI) of the difference in remission rates between foam and liquid enema groups was greater than -15% . RESULTS: Remission rates at W4 in foam versus liquid were 68.3%versus 73.6% in per protocol (PP) population (lower limit of 97.5% CI -15.1%) and 66.7%versus 70.5% in intention-to-treat (ITT) population (97.5% CI -13.4%). Remission rates at W2 were 48.1 %versus 50.6% in ITT (97.5% CI -12.8%) and 49.1%versus 52.1% in PP (97.5% CI -13.8%) in foam versus liquid, respectively. Both treatments were well tolerated. CONCLUSIONS: A 4-wk treatment of 1 g mesalamine foam induced a clinical remission in 68% patients versus 73% with 1 g mesalamine liquid enema. Although the noninferiority of mesalamine foam could not be strictly demonstrated at W4 in the PP analysis, it was achieved in the ITT population and at W2 in both populations. Mesalamine foam represents a therapeutic alternative to mesalamine liquid enema in patients with mild-to-moderate active proctitis and proctosigmoiditis.

Effects of long-term strontium ranelate treatment on the risk of nonvertebral and vertebral fractures in postmenopausal osteoporosis: Results of a five-year, randomized, placebo-controlled trial.

OBJECTIVE: This study was undertaken to assess the effect of strontium ranelate on nonvertebral and vertebral fractures in postmenopausal women with osteoporosis in a 5-year, double-blind, placebo-controlled trial. METHODS: A total of 5,091 postmenopausal women with osteoporosis were randomized to receive either strontium ranelate at 2 gm/day or placebo for 5 years. The main efficacy criterion was the incidence of nonvertebral fractures. In addition, incidence of hip fractures was assessed, by post hoc analysis, in the subset of 1,128 patients who were at high risk of fractures (age 74 years or older with lumbar spine and femoral neck bone mineral density T scores -2.4 or less). The incidence of new vertebral fractures was assessed, using the semiquantitative method described by Genant, in the 3,646 patients in whom spinal radiography (a nonmandatory procedure) was performed during the course of the study. Fracture data were analyzed using the Kaplan-Meier survival method. RESULTS: Of the 5,091 patients, 2,714 (53%) completed the study up to 5 years. The risk of nonvertebral fracture was reduced by 15% in the strontium ranelate group compared with the placebo group (relative risk 0.85 [95% confidence interval 0.73-0.99]). The risk of hip fracture was decreased by 43% (relative risk 0.57 [95% confidence interval 0.33-0.97]), and the risk of vertebral fracture was decreased by 24% (relative risk 0.76 [95% CI 0.65-0.88]) in the strontium ranelate group. After 5 years, the safety profile of strontium ranelate remained unchanged compared with the 3-year findings. CONCLUSION: Our findings indicate that treatment of postmenopausal osteoporosis with strontium ranelate results in a sustained reduction in the incidence of osteoporotic nonvertebral fractures, including hip fractures, and vertebral fractures over 5 years.

Histomorphometric and microCT analysis of bone biopsies from postmenopausal osteoporotic women treated with strontium ranelate.

UNLABELLED: Strontium ranelate is a new anti-osteoporotic treatment. On bone biopsies collected from humans receiving long-term treatment over 5 yr, it has been shown that strontium ranelate has good bone safety and better results than placebo on 3D microarchitecture. Hence, these effects may explain the decreased fracture rate. INTRODUCTION: Strontium ranelate's mode of action involving dissociation of bone formation and resorption was shown in preclinical studies and could explain its antifracture efficacy in humans. MATERIALS AND METHODS: One hundred forty-one transiliac bone biopsies were obtained from 133 postmenopausal osteoporotic women: 49 biopsies after 1-5 yr of 2 g/d strontium ranelate and 92 biopsies at baseline or after 1-5 yr of placebo. RESULTS AND CONCLUSIONS: Histomorphometry provided a 2D demonstration of the bone safety of strontium ranelate, with significantly higher mineral apposition rate (MAR) in cancellous bone (+9% versus control, p = 0.019) and borderline higher in cortical bone (+10%, p = 0.056). Osteoblast surfaces were significantly higher (+38% versus control, p = 0.047). 3D analysis of 3-yr biopsies with treatment (20 biopsies) and placebo (21 biopsies) using microCT showed significant changes in microarchitecture with, in the strontium ranelate group, higher cortical thickness (+18%, p = 0.008) and trabecular number (+14%, p = 0.05), and lower structure model index (-22%, p = 0.01) and trabecular separation (-16%, p = 0.04), with no change in cortical porosity. The changes in 3D microarchitecture may enhance bone biomechanical competence and explain the decreased fracture rate with strontium ranelate.

Euler(strut.cavity), a new histomorphometric parameter of connectivity reflects bone strength and speed of sound in trabecular bone from human os calcis.

The amount of bone and the trabecular microarchitecture are two determinants of bone strength which can be quantified by bone histomorphometry. Among the parameters of bone microarchitecture, the Euler number developed in our laboratory (E( strut.cavity )) and trabecular bone pattern factor (TBPf) evaluate the connectivity and complexity independently of the bone quantity, and the speed of sound (SOS) measured by quantitative ultrasound (QUS) corroborates E( strut.cavity ). The aim of the present study was to validate E( strut.cavity ), TBPf, and SOS as parameters of bone microarchitecture and their contribution to bone strength. We examined 20 right os calcis taken after necropsy in 11 males and 9 females, aged 52-95 years. At the same anatomic location, we measured SOS and broadband ultrasound attenuation (BUA) using a Hologic Sahara device and bone mineral density (BMD) using a Hologic QDR 1000W. At this site a transcortical cylinder was cut for both apparent density measurement (Ap.Dens) and biomechanical tests (maximum compressive stress (sigma(max)) and Young's modulus (E)), and histomorphometry was performed with an automatic image analyzer (Visiolab, Explora Nova, France). E and sigma(max) were significantly correlated with the parameters of bone quantity, microarchitecture, and QUS. However, after adjustment for the bone quantity, E correlated only with E( strut.cavity ), TBPf, and SOS, and sigma(max) with BUA. In conclusion, the bone connectivity and complexity evaluated by E( strut.cavity ) and TBPf contribute to bone strength, independently of the bone quantity. The bone mechanical properties may be assessed, in os calcis, in the elastic domain by SOS and in the plastic domain by BUA.