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Papers by Camilla Fox Maule

Research paper thumbnail of Everolimus-Eluting Bioresorbable Scaffold Versus Everolimus-Eluting Metallic Stents

Annals of internal medicine, Jan 6, 2016

TO THE EDITOR: Zhang and colleagues (1) conclude that everolimus-eluting bioresorbable vascular s... more TO THE EDITOR: Zhang and colleagues (1) conclude that everolimus-eluting bioresorbable vascular scaffolds (BVSs) pose a greater risk for stent thrombosis and myocardial infarction than everolimus-eluting metallic stents (EESs). This conclusion is somewhat misleading, because their best evidence was obtained from randomized, controlled trials (RCTs), not observational studies (2). In their analysis, summary results were not significant for RCTs. Their overall summary result (combined for observational studies and RCTs) seems to have been driven by data from observational studies. Observational studies cannot provide evidence of cause and effectthey can only provide evidence of some relationship (between exposure and outcome) (2). Discrepancies between the results of RCTs and those of observational studies are probably caused by unmeasured confounding factors in the observational studies, where each patient's treatment is specifically chosen rather than randomly assigned. Because 1 of the potential benefits of BVSs is believed to be lower risk for late stent thrombosis, patients in observational studies who were predisposed to stent thrombosis may have preferentially received these devices (3, 4). Finally, Zhang and colleagues performed metaregression for several variables and found that none of them affected the risk for stent thrombosis. However, they did not report interaction statistics for 2 important variablesuse of an intravascular imaging device and routine high-pressure postinflationboth of which are known to affect risk for stent thrombosis with BVSs (3, 4). Current BVSs are manufactured with thicker struts (typically 150 to 200 m in width) than new-generation EESs, leading to greater strut protrusion and thus greater turbulence and platelet activation (3, 4). Because of these physical characteristics, it is recommended that greater attention be placed on procedural techniques with BVSs, including use of routine intravascular imaging (that is, intravascular ultrasonography or optical coherence tomography) and high-pressure postdilation. A recent multicenter registry in which a dedicated protocol for BVS implantation significantly reduced the risk for associated stent thrombosis supports the importance of these optimizing techniques (4). They unfortunately were not frequently used in the ABSORB III trial (5), a major driver in the event rate for stent thrombosis in Zhang and colleagues' meta-analysis of the RCTs (1). In this trial, intravascular imaging was used only 11% of the time and postdilation was done 65% of the time (5). Such infrequent use of optimization techniques could have contributed to the increased incidence of stent thrombosis with BVSs.

Research paper thumbnail of Footprint Patterns and Factures in Bioresorbable Stents Implanted in Step-Down Bifurcations

Journal of the American College of Cardiology, 2016

The purpose of this paper is to demonstrate that finite element analysis can be used.Sn the desig... more The purpose of this paper is to demonstrate that finite element analysis can be used.Sn the design process for high performance fabric structures. These structures exhibit extreme geometrid. nonlinearity; specifically, the contact and interaction of fabric surfaces with the large deformation which necessarily results from membrane structures introduces great complexity to analyses of this type. All of these features are demonstrated here in the analysis of the Jet Propulsion Laboratory (JPL) Mars Pathfinder impact onto Mars. This lander system uses airbags to envelope the lander experiment package, protecting it with large deformation upon contact. Results from the analysis show the stress in the fabric airbags, forces in the internal tendon support system, forces in the latches and hinges which allow the lander to deploy after impact, and deceleration of the lander components. All of these results provide the JPL engineers with design guidance for the success of this novel lander system. Tntroducb 'on The exploration of Mars includes a survey by a small instrument laden lander, called the Mars Pathfinder, for initial definition of the Martian environment. Ths program, managed by the Jet Propulsion Laboratory, calls for the lander to impact on the surface using a parachute retarding system and a bridle mounted retro-rocket system to slow down and orient the airbag protected lander.

Research paper thumbnail of Procedural findings and early healing response after implantation of a self-apposing bioresorbable scaffold in coronary bifurcation lesions

The International Journal of Cardiovascular Imaging

Research paper thumbnail of Evaluation of Coronary Artery Stenosis by Quantitative Flow Ratio During Invasive Coronary Angiography

Circulation: Cardiovascular Imaging

F unctional evaluation is the established diagnostic standard for the assessment of intermediate ... more F unctional evaluation is the established diagnostic standard for the assessment of intermediate coronary artery stenosis in stable coronary artery disease. 1-3 Present guidelines recommend fractional flow reserve (FFR) to assess obstruction-mediated ischemia, and numerous studies have documented favorable clinical outcome of FFR-guided coronary interventions. 4-6 Many centers have not fully adopted an FFR-guided treatment

Research paper thumbnail of TCT-433 Feasibility, self-correcting properties and one-month results after implantation of a novolimus eluting bioresorbable stent in coronary bifurcations. The BIFSORB pilot study

Journal of the American College of Cardiology, 2016

Research paper thumbnail of TCT-10 Physiological testing of coronary artery stenosis by computation of invasive coronary angiography. The wire-free functional imaging (WIFI-II) study

Journal of the American College of Cardiology, 2016

Research paper thumbnail of Mechanical performance and healing patterns of the novel sirolimus-eluting bioresorbable Fantom scaffold: 6-month and 9-month follow-up by optical coherence tomography in the FANTOM II study

Open Heart

ObjectivesWe aimed to evaluate the mechanical properties and healing patterns 6 and 9 months afte... more ObjectivesWe aimed to evaluate the mechanical properties and healing patterns 6 and 9 months after implantation of the sirolimus-eluting Fantom bioresorbable scaffold (BRS).BackgroundThe Fantom BRS (Reva Medical, San Diego, USA) has differentiating properties including radiopacity, strut thickness of 125 µm, high expansion capacity and has demonstrated favourable mid-term clinical and angiographic outcomes.Methods and resultsFANTOM II was a prospective, single arm study with implantation of the Fantom BRS in 240 patients with stable angina pectoris. Guidance by optical coherence tomography (OCT) was encouraged and was repeated at 6-month (cohort A) or 9-month follow-up (cohort B). Matched baseline and follow-up OCT recordings were available in 152 patients. In-scaffold mean lumen area in cohort A was 6.8±1.7 mm2 and 5.7±1.4 mm2 at baseline and follow-up (p<0.0001) and was 7.2±1.6 mm2 and 5.6±1.4 mm2 in cohort B (p<0.0001). Mean scaffold area remained stable from 7.1±1.5 mm2 at...

Research paper thumbnail of Footprint Patterns and Factures in Bioresorbable Stents Implanted in Step-Down Bifurcations

Journal of the American College of Cardiology, 2016

Research paper thumbnail of Everolimus-Eluting Bioresorbable Scaffold Versus Everolimus-Eluting Metallic Stents

Annals of internal medicine, Jan 6, 2016

TO THE EDITOR: Zhang and colleagues (1) conclude that everolimus-eluting bioresorbable vascular s... more TO THE EDITOR: Zhang and colleagues (1) conclude that everolimus-eluting bioresorbable vascular scaffolds (BVSs) pose a greater risk for stent thrombosis and myocardial infarction than everolimus-eluting metallic stents (EESs). This conclusion is somewhat misleading, because their best evidence was obtained from randomized, controlled trials (RCTs), not observational studies (2). In their analysis, summary results were not significant for RCTs. Their overall summary result (combined for observational studies and RCTs) seems to have been driven by data from observational studies. Observational studies cannot provide evidence of cause and effectthey can only provide evidence of some relationship (between exposure and outcome) (2). Discrepancies between the results of RCTs and those of observational studies are probably caused by unmeasured confounding factors in the observational studies, where each patient's treatment is specifically chosen rather than randomly assigned. Because 1 of the potential benefits of BVSs is believed to be lower risk for late stent thrombosis, patients in observational studies who were predisposed to stent thrombosis may have preferentially received these devices (3, 4). Finally, Zhang and colleagues performed metaregression for several variables and found that none of them affected the risk for stent thrombosis. However, they did not report interaction statistics for 2 important variablesuse of an intravascular imaging device and routine high-pressure postinflationboth of which are known to affect risk for stent thrombosis with BVSs (3, 4). Current BVSs are manufactured with thicker struts (typically 150 to 200 m in width) than new-generation EESs, leading to greater strut protrusion and thus greater turbulence and platelet activation (3, 4). Because of these physical characteristics, it is recommended that greater attention be placed on procedural techniques with BVSs, including use of routine intravascular imaging (that is, intravascular ultrasonography or optical coherence tomography) and high-pressure postdilation. A recent multicenter registry in which a dedicated protocol for BVS implantation significantly reduced the risk for associated stent thrombosis supports the importance of these optimizing techniques (4). They unfortunately were not frequently used in the ABSORB III trial (5), a major driver in the event rate for stent thrombosis in Zhang and colleagues' meta-analysis of the RCTs (1). In this trial, intravascular imaging was used only 11% of the time and postdilation was done 65% of the time (5). Such infrequent use of optimization techniques could have contributed to the increased incidence of stent thrombosis with BVSs.

Research paper thumbnail of Footprint Patterns and Factures in Bioresorbable Stents Implanted in Step-Down Bifurcations

Journal of the American College of Cardiology, 2016

The purpose of this paper is to demonstrate that finite element analysis can be used.Sn the desig... more The purpose of this paper is to demonstrate that finite element analysis can be used.Sn the design process for high performance fabric structures. These structures exhibit extreme geometrid. nonlinearity; specifically, the contact and interaction of fabric surfaces with the large deformation which necessarily results from membrane structures introduces great complexity to analyses of this type. All of these features are demonstrated here in the analysis of the Jet Propulsion Laboratory (JPL) Mars Pathfinder impact onto Mars. This lander system uses airbags to envelope the lander experiment package, protecting it with large deformation upon contact. Results from the analysis show the stress in the fabric airbags, forces in the internal tendon support system, forces in the latches and hinges which allow the lander to deploy after impact, and deceleration of the lander components. All of these results provide the JPL engineers with design guidance for the success of this novel lander system. Tntroducb 'on The exploration of Mars includes a survey by a small instrument laden lander, called the Mars Pathfinder, for initial definition of the Martian environment. Ths program, managed by the Jet Propulsion Laboratory, calls for the lander to impact on the surface using a parachute retarding system and a bridle mounted retro-rocket system to slow down and orient the airbag protected lander.

Research paper thumbnail of Procedural findings and early healing response after implantation of a self-apposing bioresorbable scaffold in coronary bifurcation lesions

The International Journal of Cardiovascular Imaging

Research paper thumbnail of Evaluation of Coronary Artery Stenosis by Quantitative Flow Ratio During Invasive Coronary Angiography

Circulation: Cardiovascular Imaging

F unctional evaluation is the established diagnostic standard for the assessment of intermediate ... more F unctional evaluation is the established diagnostic standard for the assessment of intermediate coronary artery stenosis in stable coronary artery disease. 1-3 Present guidelines recommend fractional flow reserve (FFR) to assess obstruction-mediated ischemia, and numerous studies have documented favorable clinical outcome of FFR-guided coronary interventions. 4-6 Many centers have not fully adopted an FFR-guided treatment

Research paper thumbnail of TCT-433 Feasibility, self-correcting properties and one-month results after implantation of a novolimus eluting bioresorbable stent in coronary bifurcations. The BIFSORB pilot study

Journal of the American College of Cardiology, 2016

Research paper thumbnail of TCT-10 Physiological testing of coronary artery stenosis by computation of invasive coronary angiography. The wire-free functional imaging (WIFI-II) study

Journal of the American College of Cardiology, 2016

Research paper thumbnail of Mechanical performance and healing patterns of the novel sirolimus-eluting bioresorbable Fantom scaffold: 6-month and 9-month follow-up by optical coherence tomography in the FANTOM II study

Open Heart

ObjectivesWe aimed to evaluate the mechanical properties and healing patterns 6 and 9 months afte... more ObjectivesWe aimed to evaluate the mechanical properties and healing patterns 6 and 9 months after implantation of the sirolimus-eluting Fantom bioresorbable scaffold (BRS).BackgroundThe Fantom BRS (Reva Medical, San Diego, USA) has differentiating properties including radiopacity, strut thickness of 125 µm, high expansion capacity and has demonstrated favourable mid-term clinical and angiographic outcomes.Methods and resultsFANTOM II was a prospective, single arm study with implantation of the Fantom BRS in 240 patients with stable angina pectoris. Guidance by optical coherence tomography (OCT) was encouraged and was repeated at 6-month (cohort A) or 9-month follow-up (cohort B). Matched baseline and follow-up OCT recordings were available in 152 patients. In-scaffold mean lumen area in cohort A was 6.8±1.7 mm2 and 5.7±1.4 mm2 at baseline and follow-up (p<0.0001) and was 7.2±1.6 mm2 and 5.6±1.4 mm2 in cohort B (p<0.0001). Mean scaffold area remained stable from 7.1±1.5 mm2 at...

Research paper thumbnail of Footprint Patterns and Factures in Bioresorbable Stents Implanted in Step-Down Bifurcations

Journal of the American College of Cardiology, 2016