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Monreal G, Koenig SC, Kelley JF, Illg JJ, Tamez D, Kelley MS, Yetukuri V, Cross DP, Theran ME, Slaughter MS. Early-stage Development of the CoRISMA Mechanical Circulatory Support (CMCS) System for Heart Failure Therapy. Cardiovasc Eng Technol 2024:10.1007/s13239-024-00743-0. [PMID: 39037566 DOI: 10.1007/s13239-024-00743-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 07/05/2024] [Indexed: 07/23/2024]
Abstract
PURPOSE CoRISMA MCS Systems Inc (Hamden CT) is developing an innovative mechanical circulatory support system (CMCS) as a durable therapeutic option for heart failure (HF) patients. The CMCS system is comprised of an axial flow pump, non-contacting hydrodynamic bearings, and integrated DC motor designed to be fully implantable in a left atrial (LA) to aortic (Ao) configuration; this unloading strategy may be particularly beneficial for HF patients with preserved ejection fraction (HFpEF). The small (5.5 cm3), lightweight (20 g), and low power (5-7 W) device design should allow for a less invasive off-pump implant. We present early-stage engineering development and testing of the prototype CoRISMA pumps. METHODS Computational fluid dynamics (CFD) modeling was performed to evaluate flow and shear in two impeller (3 blades, 0.5 mm thickness, 8.9 mm diameter, 0.15 mm gap, polished titanium) and diffusor (5 blades, polished titanium) candidate designs. Test apparatuses were custom built to expedite development of the impeller/diffuser designs and iteratively refine the CFD models. Two candidate impeller/diffusor designs were fabricated and tested in each of the two test apparatuses (n = 4 impeller/diffuser + test fixture configurations) in static mock flow loops (hydrodynamic H-Q curves, 3.5 cP glycerol solution at 37 °C), and in dynamic mock flow loops (hemodynamics, 3.5 cP glycerol solution at 37 °C) tuned to HF conditions (mean aortic pressure 50 mmHg, central venous pressure 15 mmHg, aortic flow 3.0 L/min, and heart rate 80 bpm). RESULTS CFD predicted flows of 4.56 L/min and 4.82 L/min at 100 mmHg for impellers/diffusers 1 and 2, respectively. Impeller 2 required less torque to generate a 6% increase in fluidic flow, and the diffuser had a larger area of high pressure, indicative of lower friction, which likely contributed to the increased efficiency. Experimental testing for all four configurations in the static and dynamic mock loops met performance metrics as evidenced by generating 4.0-4.5 L/min flow against 70-76 mmHg pressure at 25,000 rpm and restoring hemodynamics in the dynamic mock flow loop (MAP = 80 mmHg, CVP = 0 mmHg, total flow = 5.5 L/min) from baseline simulated HF test conditions. CONCLUSION These results demonstrate proof-of-concept of the early engineering design and performance of the prototype CoRISMA pumps. Engineering specifications, challenges observed, and proposed solutions for the next design iteration were identified for the continued development of an effective, reliable, and safe LA-to-Ao CMCS system for HF patients. Current design plans are underway for incorporating a wireless energy transfer system for communication and power, eliminating the need for and complications associated with an external driveline, to achieve a fully-implantable system.
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Affiliation(s)
- Gretel Monreal
- Department of Cardiovascular and Thoracic Surgery, University of Louisville, 302 E. Muhammad Ali Blvd, Room 411, Louisville, KY, 40202, USA.
| | - Steven C Koenig
- Department of Cardiovascular and Thoracic Surgery, University of Louisville, 302 E. Muhammad Ali Blvd, Room 411, Louisville, KY, 40202, USA
- Department of Bioengineering, University of Louisville, Louisville, KY, USA
| | | | | | | | | | | | | | | | - Mark S Slaughter
- Department of Cardiovascular and Thoracic Surgery, University of Louisville, 302 E. Muhammad Ali Blvd, Room 411, Louisville, KY, 40202, USA
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Langer N, Stephens AF, Šeman M, McGiffin D, Kaye DM, Gregory SD. HeartMate 3 for Heart Failure with Preserved Ejection Fraction: In Vitro Hemodynamic Evaluation and Anatomical Fitting. Ann Biomed Eng 2024:10.1007/s10439-024-03585-y. [PMID: 39014052 DOI: 10.1007/s10439-024-03585-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 07/08/2024] [Indexed: 07/18/2024]
Abstract
Heart failure with preserved ejection fraction (HFpEF) constitutes approximately 50% of heart failure (HF) cases, and encompasses different phenotypes. Among these, most patients with HFpEF exhibit structural heart changes, often with smaller left ventricular cavities, which pose challenges for utilizing ventricular assist devices (VADs). A left atrial to aortic (LA-Ao) VAD configuration could address these challenges, potentially enhancing patient quality of life by lowering elevated mean left atrial pressure (MLAP). This study assessed the anatomical compatibility and left atrial unloading capacity using a simulated VAD-supported HFpEF patient. A HeartMate3-supported HFpEF patient in an LA-Ao configuration was simulated using a cardiovascular simulator. Hemodynamic parameters were recorded during rest and exercise at seven pump flow rates. Computed tomography scans of 14 HFpEF (NYHA II-III) and six heart failure with reduced ejection fraction patients were analysed for anatomical comparisons. HFpEF models were independently assessed for virtual anatomical fit with the HM3 in the LA-Ao configuration. Baseline MLAP was reduced from 15 to 11 mmHg with the addition of 1 L/min HM3 support in the rest condition. In an exercise simulation, 6 L/min of HM3 support was required to reduce the MLAP from 29 to 16 mmHg. The HM3 successfully accommodated six HFpEF patients without causing interference with other cardiac structures, whereas it caused impingement ranging from 4 to 14 mm in the remaining patients. This study demonstrated that the HM3 in an LA-Ao configuration may be suitable for unloading the left atrium and relieving pulmonary congestion in some HFpEF patients where size-related limitations can be addressed through pre-surgical anatomical fit analysis.
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Affiliation(s)
- Nina Langer
- Cardio-Respiratory Engineering and Technology Laboratory (CREATElab), Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC, Australia.
- Victorian Heart Institute, Victorian Heart Hospital, Melbourne, VIC, Australia.
- Victorian Heart Hospital, Melbourne, VIC, Australia.
| | - Andrew F Stephens
- Cardio-Respiratory Engineering and Technology Laboratory (CREATElab), Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC, Australia
- Victorian Heart Institute, Victorian Heart Hospital, Melbourne, VIC, Australia
| | - Michael Šeman
- Cardio-Respiratory Engineering and Technology Laboratory (CREATElab), Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC, Australia
- School of Public Health and Preventative Medicine, Monash University, Melbourne, VIC, Australia
- The Department of Cardiology, The Alfred Hospital, Melbourne, VIC, Australia
| | - David McGiffin
- Department of Cardiothoracic Surgery, The Alfred, Melbourne, VIC, Australia
| | - David M Kaye
- The Department of Cardiology, The Alfred Hospital, Melbourne, VIC, Australia
| | - Shaun D Gregory
- Cardio-Respiratory Engineering and Technology Laboratory (CREATElab), Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC, Australia
- Victorian Heart Institute, Victorian Heart Hospital, Melbourne, VIC, Australia
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Tian D, Zhang J, He Y, Xiong Z, Zhao M, Hu S, Song Q, Li Z. Predictive value of left atrial strain analysis in adverse clinical events in patients with hypertrophic cardiomyopathy: a CMR study. BMC Cardiovasc Disord 2023; 23:42. [PMID: 36690952 PMCID: PMC9869521 DOI: 10.1186/s12872-023-03069-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 01/16/2023] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND A subset of patients with hypertrophic cardiomyopathy (HCM) will experience adverse clinical events such as heart failure (HF), cardiovascular death, and new-onset atrial fibrillation (AF). Current risk stratification methods are imperfect and limit the identification of patients at high risk for HCM. This study aimed to evaluate the role of cardiac magnetic resonance (CMR)-derived left atrial strain parameters in the occurrence of adverse clinical events in patients with HCM. METHODS Left atrial (LA) structural, functional, and strain parameters were evaluated in 99 patients with HCM and compared with 89 age-, sex-, and BMI-matched control subjects. LA strain parameters were derived from CMR two- and four-chamber cine images by a semiautomatic method. LA strain parameters include global longitudinal strain (GLS) and global circumferential strain (GCS). The LA GLS includes reservoir strain (GLS reservoir), conduit strain (GLS conduit), and booster strain (GLS booster). Three LA GLS strain rate (SR) parameters were derived: SR reservoir, SR conduit, and SR booster. The primary endpoint was set as a composite of adverse clinical events, including SCD, new-onset or worsening to hospitalized HF, new-onset AF, thromboembolic events, and fatal ventricular arrhythmias. RESULTS LA GLS, GLS SR and GCS were impaired in HCM patients compared to control subjects (all p < 0.001). After a mean follow-up of 37.94 ± 23.69 months, 18 HCM patients reached the primary endpoint. LA GLS, GLS SR, and GCS were significantly lower in HCM patients with adverse clinical events than in those without adverse clinical events (all p < 0.05). In stepwise multiple Cox regression analysis, LV SV, LA diameter, pre-contraction LAV (LAV pre-ac), passive LA ejection fraction (EF), and LA GLS booster were all independent determinants of adverse clinical events. LA GLS booster ≤ 8.9% was the strongest determinant (HR = 8.9 [95%CI (1.951, 40.933)], p = 0.005). Finally, LA GLS booster provided predictive adverse clinical events value (AUC = 0.86 [95%CI 0.77-0.98]) that exceeded traditional outcome predictors. CONCLUSION LA strain assessment, a measure of LA function, provides additional predictive information for established predictors of HCM patients. LA GLS booster was independently associated with adverse clinical events in patients with HCM.
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Affiliation(s)
- Di Tian
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Zhongshan Road No. 222, Xigang District, Dalian, 116011 China
| | - JingYu Zhang
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Zhongshan Road No. 222, Xigang District, Dalian, 116011 China
| | - YiFan He
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Zhongshan Road No. 222, Xigang District, Dalian, 116011 China
| | - ZiQi Xiong
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Zhongshan Road No. 222, Xigang District, Dalian, 116011 China
| | - Min Zhao
- Pharmaceutical Diagnostics, GE Healthcare, Beijing, China
| | - Shuai Hu
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Zhongshan Road No. 222, Xigang District, Dalian, 116011 China
| | - QingWei Song
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Zhongshan Road No. 222, Xigang District, Dalian, 116011 China
| | - ZhiYong Li
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Zhongshan Road No. 222, Xigang District, Dalian, 116011 China
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Comparison of device-based therapy options for heart failure with preserved ejection fraction: a simulation study. Sci Rep 2022; 12:5761. [PMID: 35388023 PMCID: PMC8987034 DOI: 10.1038/s41598-022-09637-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 03/25/2022] [Indexed: 12/29/2022] Open
Abstract
Successful therapy of heart failure with preserved ejection fraction (HFpEF) remains a major unmet clinical need. Device-based treatment approaches include the interatrial shunt device (IASD), conventional assist devices pumping blood from the left ventricle (LV-VAD) or the left atrium (LA-VAD) towards the aorta, and a valveless pulsatile assist device with a single cannula operating in co-pulsation with the native heart (CoPulse). Hemodynamics of two HFpEF subgroups during rest and exercise condition were translated into a lumped parameter model of the cardiovascular system. The numerical model was applied to assess the hemodynamic effect of each of the four device-based therapies. All four therapy options show a reduction in left atrial pressure during rest and exercise and in both subgroups (> 20%). IASDs concomitantly reduce cardiac output (CO) and shift the hemodynamic overload towards the pulmonary circulation. All three mechanical assist devices increase CO while reducing sympathetic activity. LV-VADs reduce end-systolic volume, indicating a high risk for suction events. The heterogeneity of the HFpEF population requires an individualized therapy approach based on the underlying hemodynamics. Whereas phenotypes with preserved CO may benefit most from an IASD device, HFpEF patients with reduced CO may be candidates for mechanical assist devices.
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