Configuration of two-stent coronary bifurcation techniques in explanted beating hearts: the MOBBEM study.

BACKGROUND: In patients with complex coronary bifurcation lesions undergoing percutaneous coronary intervention (PCI), various 2-stent techniques might be utilised. The Visible Heart Laboratories (VHL) offer an experimental environment where PCI results can be assessed by multimodality imaging. AIMS: We aimed to assess the post-PCI stent configuration achieved by 2-stent techniques in the VHL and to evaluate the procedural factors associated with suboptimal results. METHODS: Bifurcation PCI with 2-stent techniques, performed by expert operators in the VHL on explanted beating swine hearts, was studied. The adopted bifurcation PCI strategy and the specific procedural steps applied in each procedure were classified according to Main, Across, Distal, Side (MADS)-2 and to their adherence to the European Bifurcation Club (EBC) recommendations. Microcomputed tomography (micro-CT) was used to assess the post-PCI stent configuration. The primary endpoint was "suboptimal stent implantation", defined as a composite of stent underexpansion (<90%), side branch ostial area stenosis >50% and the gap between stents. RESULTS: A total of 82 PCI with bifurcation stenting were assessed, comprised of 29 crush, 25 culotte, 28 T/T and small protrusion (TAP) techniques. Suboptimal stent implantation was observed in as many as 53.7% of the cases, regardless of baseline anatomy or the stenting strategy. However, less frequent use of the proximal optimisation technique (POT; p=0.015) and kissing balloon inflations (KBI; p=0.027) and no adherence to EBC recommendations (p=0.004, p multivariate=0.006) were significantly associated with the primary endpoint. CONCLUSIONS: Commonly practised bifurcation 2-stent techniques may result in imperfect stent configurations. More frequent use of POT/KBI and adherence to expert recommendations might reduce the occurrence of post-PCI suboptimal stent configurations.

Multimodal Comparisons of Results Achieved by Different Side Branch Ballooning Techniques for Bifurcation Provisional Stenting.

BACKGROUND: Stepwise provisional stenting is the gold standard for percutaneous coronary intervention (PCI) on bifurcation lesions, but the optimal ballooning technique for eventual side branch treatment is not established. The objective of the present study was to compare the stent configuration obtained by 2 different side branch optimization techniques performed after main vessel (MV) stent implantation: proximal optimization technique+kissing balloon inflation+final proximal optimization technique (POT/KBI/POT [PKP]) versus proximal optimization technique+isolated side branch dilation+final proximal optimization technique (POT-side-POT [PSP]). METHODS: We realized a 1:1 prospective randomized trial comparing bifurcation PCI conducted (under angiographic and angioscopic visualization) with either PKP or PSP in reanimated swine hearts using commercially available drug-eluting stents. After PCI, the obtained stent configuration (expansion, eccentricity, apposition) was assessed by optical coherence tomography and micro-computed tomography dividing the stent in 4 segments. Primary study end point was minimum stent expansion at the distal MV segment. RESULTS: A total of 30 PCIs were successfully performed according to randomization obtaining overall good results (average minimum stent expansion >90% at optical coherence tomography and micro-computed tomography) with PSP or PKP. Minimum stent expansion at the distal MV segment was significantly higher with PKP as compared with PSP at optical coherence tomography (97.9±4.2% versus 91.0±7.7%; P=0.002) and micro-computed tomography (98.1±4.1% versus 91.3±7.9%; P=0.006). Other significant findings included higher stent eccentricity index at proximal MV with PSP, higher side branch scaffolding length and lower malapposition (at bifurcation core and distal MV) with PKP. CONCLUSIONS: This first prospective randomized trial in a unique non-atherosclerotic preclinical environment showed that bifurcation PCI conducted with PSP and PKP achieves different stent configurations. These findings might be useful in bifurcation PCI practice and call for further evaluations in clinical ground.

Multimodal Imaging of a Chimney-Stenting Procedure Performed Simultaneously with a Transcatheter Aortic Valve Replacement (TAVR) in a Reanimated Human Heart including Post-Implant Analyses.

Transcatheter aortic valve replacement (TAVR) has become a popular treatment option for severe aortic stenosis for patients with a high risk for mortality with surgical aortic valve replacement (SAVR). Coronary artery occlusion (CAO) following the implantation of the device is a potential and sometimes devastating complication of this procedure, that provokes a sudden deterioration of hemodynamic status followed by cardiogenic shock and electrical instability. With patients that present a high risk for coronary obstruction, coronary protection with a chimney stenting technique is an effective strategy that can ensure coronary perfusion during TAVR in case of acute CAO. Utilizing Visible Heart® methodologies, a human heart was reanimated. A chimney stenting technique was implemented simultaneously with the deployment of a Medtronic Evolut™ Pro+ valve (Medtronic PLC; Minneapolis, MN, USA). The entire procedure was recorded utilizing endoscopic cameras, fluoroscopy, optical coherence tomography, and echocardiography. In addition to these procedural visualizations, post-procedural micro-computed tomography (micro-CT) was conducted to provide post-implantation imaging with approximately 60-micron resolution. Utilizing these imaging modalities in a reanimated human heart allows for the unique opportunity to collect data for TAVR procedures in real human anatomies for the subsequent educational uses by the physicians treating aortic valvular disease and/or the designers of future TAVR technologies and procedures.

Quantified biomechanical properties of lower lumbar myofascia in younger adults with chronic idiopathic low back pain and matched healthy controls.

BACKGROUND: Non-specific chronic low back pain (LBP) is a prevalent condition that is poorly understood with respect to possible altered physical properties. Five biomechanical properties of stiffness, frequency, decrement, creep, and stress relaxation time of the L3-L4 myofascial tissue were quantified using the MyotonPro® in chronic idiopathic LBP and matched normal control subjects. METHODS: Measurements were obtained in the resting prone position on the left and right sides (initially and after 10 min rest) in 25 chronic LBP participants (16 female, 9 male) and 25 age- and sex-matched control subjects. Surface electromyography measurements were simultaneously conducted to ensure a resting state. FINDINGS: Female LBP had significantly greater median decrement (p < 0.001) and stiffness (p < 0.010) than female controls. In female LBP patients, BMI correlated with decrement (p < 0.010) and creep (p < 0.050); creep also correlated with decrement (p < 0.050). Significant male versus female differences were found in all five properties in both LBP and control subgroups, except decrement in control males versus females. INTERPRETATION: This study showed that greater median decrement was found in LBP female subjects suggesting decrease in elasticity in the lumbar myofascia. Most of the biomechanical properties differed significantly by gender. This study further documented that right-handed dominance might correlate with greater right-sided lumbar myofascial stiffness.