RESUMO
BACKGROUND: In patients with heart failure, interventions to reduce elevated left atrial pressure improve symptoms and reduce the risk of hospital admission. We aimed to assess the safety and potential efficacy of therapeutic left-to-right interatrial shunting in patients with heart failure with reduced ejection fraction. METHODS: We did this proof-of-principle cohort study at one centre in Canada. Patients (aged ≥18 years) with New York Heart Association (NYHA) class III chronic heart failure with reduced ejection fraction were enrolled under the Canadian special access programme. Shunt implants were done after transseptal catheterisation with transoesophageal echocardiographic guidance under general anaesthesia. Patients had clinical and echocardiography evaluations at baseline and months 1 and 3 after shunt implantation. FINDINGS: Between Oct 10, 2013, and March 27, 2015, we enrolled ten patients. The device was successfully implanted in all patients; no device-related or procedural adverse events occurred during follow-up. Transoesophageal echocardiography at 1 month showed that all shunts were patent, with no thrombosis or migration. From baseline to 3 month follow-up, we recorded improvements in NYHA classification (from class III to class II in seven [78%] of nine patients, from class III to class I in one [11%] patient, and no change in one [11%] patient; p=0·0004); quality of life, as assessed by the Duke Activity Status Index (from a mean score of 13 [SD 6·2] to 24·8 [12·9]; p=0·016) and the Kansas City Cardiomyopathy Questionnaire (from a mean score of 44·3 [SD 9·8] to 79·1 [13·0]; p=0·0001); and 6 min walk test distance (from a mean of 244 m [SD 112] to 318 m [134]; p=0·016). Pulmonary capillary wedge pressure was reduced from a mean of 23 mm Hg (SD 5) at baseline to 17 mm Hg (8) at 3 months (p=0·035), with no changes in right atrial pressure, pulmonary arterial pressure, or pulmonary resistance. No patient was admitted to hospital for worsening heart failure. One (10%) patient was admitted to hospital with gastrointestinal bleeding at month 1; one (10%) patient died after incessant ventricular tachycardia storm, which led to terminal heart failure 2 months post-procedure. INTERPRETATION: This first-in-man experience with an implanted left-to-right interatrial shunt demonstrates initial safety and early beneficial clinical and haemodynamic outcomes in patients with heart failure with reduced ejection fraction. Further large-scale randomised studies are warranted. FUNDING: V-Wave.
Assuntos
Insuficiência Cardíaca/cirurgia , Canadá , Procedimentos Cirúrgicos Cardíacos/métodos , Estudos de Coortes , Feminino , Átrios do Coração/cirurgia , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Próteses e Implantes , Desenho de Prótese , Volume SistólicoRESUMO
BACKGROUND: Daily measurements of left atrial pressure (LAP) may be useful for guiding adjustments in medical therapy that prevent clinical decompensation in patients with severe heart failure (HF). STUDY DESIGN: LAPTOP-HF is a prospective, multicenter, randomized, controlled clinical trial in ambulatory patients with advanced heart failure in which the safety and clinical effectiveness of a physician-directed patient self-management therapeutic strategy based on LAP measured twice daily by means of an implantable sensor will be compared with a control group receiving optimal medical therapy. The trial will enroll up to 730 patients with New York Heart Association functional class III symptoms and either a hospitalization for HF during the previous 12 months or an elevated B-type natriuretic peptide level, regardless of ejection fraction, at up to 75 investigational centers. Randomization to the treatment group or control group will be at a 1:1 ratio in 3 strata based on the ejection fraction (EF > or ≤35%) and the presence of a de novo CRT device indication. SUMMARY: LAPTOP-HF will provide essential information about the role of implantable LAP monitoring in conjunction with a new HF treatment paradigm across the spectrum of HF patients.
Assuntos
Pressão Atrial , Fármacos Cardiovasculares/uso terapêutico , Insuficiência Cardíaca , Monitorização Ambulatorial , Autocuidado , Adulto , Cateterismo Cardíaco/métodos , Terapia de Ressincronização Cardíaca/métodos , Feminino , Átrios do Coração/fisiopatologia , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Ambulatorial/instrumentação , Monitorização Ambulatorial/métodos , Peptídeo Natriurético Encefálico/sangue , Avaliação de Resultados em Cuidados de Saúde , Estudos Prospectivos , Autocuidado/instrumentação , Autocuidado/métodos , Índice de Gravidade de Doença , Volume SistólicoRESUMO
The rationale for intrathoracic impedance (Z) detection of worsening heart failure (HF) presupposes that changes in Z reflect changes in pulmonary congestion, but is confounded by poor specificity in clinical trials. We therefore tested the hypothesis that Z is primarily affected by tissue/water content in proximity to electrodes rather than by lung water distribution between electrodes through the use of a new computational model for deriving the near-field impedance contributions from the various electrodes. Six sheep were implanted with a left atrial pressure (LAP) monitor and a cardiac resynchronization therapy device which measured Z from six vectors comprising of five electrodes. The vector-based Z was modelled as the summation of the near-field impedances of the two electrodes forming the vector. During volume expansion an acute increase in LAP resulted in simultaneous reductions in the near-field impedances of the intra-cardiac electrodes, while the subcutaneous electrode showed several hours of lag (all p<0.001). In contrast, during the simulated formation of device-pocket edema (induced by fluid injection) the near-field impedance of the subcutaneous electrode had an instantaneous response, while the intra-cardiac electrodes had a minimal inconsistent response. This study suggests that the primary contribution to the vector based Z is from the tissue/water in proximity to the individual electrodes. This novel finding may help explain the limited utility of Z for detecting worsening HF.
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Cardiografia de Impedância/métodos , Impedância Elétrica , Insuficiência Cardíaca/diagnóstico , Pulmão/patologia , Algoritmos , Anestesia Geral , Animais , Determinação da Pressão Arterial/métodos , Simulação por Computador , Edema/patologia , Eletrodos , Átrios do Coração/patologia , Insuficiência Cardíaca/patologia , Monitorização Fisiológica/métodos , Edema Pulmonar/diagnóstico , Ovinos , Fatores de Tempo , Água/químicaRESUMO
BACKGROUND: We hypothesized that left atrial pressure (LAP) obtained by a permanent implantable sensor is sensitive to changes in cardiac resynchronization therapy (CRT) settings and could guide CRT optimization to improve the response rate. We investigated the effect of CRT optimization on LAP and its waveform parameters in ambulant heart failure (HF) patients. METHODS: CRT optimization was performed in eight ambulant HF patients, using echocardiography as reference. LAP waveform was acquired at each of eight atrioventricular (AV) intervals and five inter-ventricular (VV) intervals. Selected waveform parameters were also evaluated for their sensitivity to CRT changes and agreement with echocardiography-guided optimal settings. RESULTS: Optimal AV and VV intervals varied considerably between patients. All patients exhibited significant changes in waveform morphology with AV optimization. Optimal AV delay determined from echocardiography ranged between 140 ms and 225 ms. Mean LAP tended to be lower at optimal setting 14 ± 3 mmHg compared to shorter (<100 ms) or longer (>160 ms) AV settings (P = 0.16). There were clear trends to smaller peak a-wave (P = 0.11) and gentler positive a-slope (P = 0.15) and positive v-slope (P = 0.09) with longer AV delays. Mean LAP and negative v-wave slope correlated well with echo-guided optimal setting, r = 0.91 (P = 0.001) and 0.79 (P = 0.03), respectively. No significant effects on LAP or waveform were seen during VV optimization. CONCLUSIONS: LAP and its waveform changes considerably with AV optimization. There is good agreement between echo-guided optimal setting and LAP. LAP could provide an objective guide to CRT optimization. (Clinical Trial Registry information: URL: http://www.clinicaltrials.gov. Unique Identifier: NCT00632372).
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Pressão Atrial , Terapia de Ressincronização Cardíaca/métodos , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Adulto , Idoso , Estudos de Viabilidade , Humanos , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
AIMS: Heart failure (HF) outcomes remain poor despite optimal guideline-directed medical therapy (GDMT). We assessed safety, effectiveness, and transthoracic echocardiographic (TTE) outcomes during the 12 months after Ventura shunt implantation in the RELIEVE-HF open-label roll-in cohort. METHODS AND RESULTS: Eligibility required symptomatic HF despite optimal GDMT with ≥1 HF hospitalization in the prior year or elevated natriuretic peptides. The safety endpoint was device-related major adverse cardiovascular or neurological events at 30 days, compared to a prespecified performance goal. Effectiveness evaluations included the Kansas City Cardiomyopathy Questionnaire (KCCQ) at baseline, 1, 3, 6, and 12 months and TTE at baseline and 12 months. Overall, 97 patients were enrolled and implanted at 64 sites. Average age was 70 ± 11 years, 97% were in New York Heart Association class III, and half had left ventricular ejection fraction (LVEF) ≤40%. The safety endpoint was achieved (event rate 0%, p < 0.001). KCCQ overall summary score was improved by 12-16 points at all follow-up timepoints (all p < 0.004), with similar outcomes in patients with reduced and preserved LVEF. At 12 months, left ventricular end-systolic and end-diastolic volumes were reduced (p = 0.020 and p = 0.038, respectively), LVEF improved (p = 0.009), right ventricular end-systolic and end-diastolic areas were reduced (p = 0.001 and p = 0.030, respectively), and right ventricular fractional area change (p < 0.001) and tricuspid annular plane systolic excursion (p < 0.001) improved. CONCLUSION: Interatrial shunting with the Ventura device was safe and resulted in favourable clinical effects in patients with HF, regardless of LVEF. Improvements of left and right ventricular structure and function were consistent with reverse myocardial remodelling. These results would support the potential of this shunt device as a treatment for HF.
Assuntos
Ecocardiografia , Insuficiência Cardíaca , Volume Sistólico , Humanos , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Feminino , Masculino , Idoso , Volume Sistólico/fisiologia , Ecocardiografia/métodos , Resultado do Tratamento , Função Ventricular Esquerda/fisiologia , Átrios do Coração/fisiopatologia , Átrios do Coração/diagnóstico por imagem , Pessoa de Meia-IdadeRESUMO
AIMS: Interatrial shunts are under evaluation as a treatment for heart failure (HF); however, their in vivo flow performance has not been quantitatively studied. We aimed to investigate the fluid dynamics properties of the 0.51 cm orifice diameter Ventura shunt and assess its lumen integrity with serial transesophageal echocardiography (TEE). METHODS AND RESULTS: Computational fluid dynamics (CFD) and bench flow tests were used to establish the flow-pressure relationship of the shunt. Open-label patients from the RELIEVE-HF trial underwent TEE at shunt implant and at 6 and 12 month follow-up. Shunt effective diameter (Deff) was derived from the vena contracta, and flow was determined by the continuity equation. CFD and bench studies independently validated that the shunt's discharge coefficient was 0.88 to 0.89. The device was successfully implanted in all 97 enrolled patients; mean age was 70 ± 11 years, 97% were NYHA class III, and 51% had LVEF ≤40%. Patency was confirmed in all instances, except for one stenotic shunt at 6 months. Deff remained unchanged from baseline at 12 months (0.47 ± 0.01 cm, P = 0.376), as did the trans-shunt mean pressure gradient (5.1 ± 3.9 mmHg, P = 0.316) and flow (1137 ± 463 mL/min, P = 0.384). TEE measured flow versus pressure closely correlated (R2 ≥ 0.98) with a fluid dynamics model. At 12 months, the pulmonary/systemic flow Qp/Qs ratio was 1.22 ± 0.12. CONCLUSIONS: When implanted in patients with advanced HF, this small interatrial shunt demonstrated predictable and durable patency and performance.
RESUMO
BACKGROUND: An implantable left atrial pressure (LAP) monitoring system for guiding the management of patients with advanced heart failure has the potential to require extraction, particularly in the setting of infection. The LAP sensor lead was designed to be suitable for ease of percutaneous extraction using standard techniques for extracting pacemaker and defibrillator leads. The clinical experience, to date, with percutaneous extraction of the LAP sensor lead is presented. METHODS: A total of 82 patients underwent successful implantation of the LAP sensor lead using transseptal catheterization. Five patients of the 82 patients during a cumulative follow-up period of 267 patient-years (median of 2.9 years/patient) underwent percutaneous extraction using manual traction with a locking stylet and/or an excimer laser sheath to bore through adhesions. The distal fixation anchors of the LAP sensor lead are designed to fold forward during extraction so that the sensor module can easily separate from the interatrial septum. RESULTS: Percutaneous extraction of the LAP sensor lead was accomplished successfully in all five patients with no embolic events, vascular tears, perforations, or other complications requiring surgical intervention. Manual traction alone was sufficient to detach the LAP sensor lead from the interatrial septum in all cases. Use of the excimer laser sheath was needed in selected cases to bore through scar tissue within the venous insertion site, but not within the heart. CONCLUSIONS: The extraction of the LAP sensor lead was accomplished safely using standard techniques and equipment for percutaneously extracting pacemaker and defibrillator leads.
Assuntos
Determinação da Pressão Arterial/instrumentação , Remoção de Dispositivo/métodos , Átrios do Coração/fisiopatologia , Átrios do Coração/cirurgia , Insuficiência Cardíaca/fisiopatologia , Próteses e Implantes , Transdutores de Pressão , Idoso , Determinação da Pressão Arterial/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Feminino , Insuficiência Cardíaca/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Resultado do TratamentoRESUMO
BACKGROUND: Previous studies suggest that management of ambulatory hemodynamics may improve outcomes in chronic heart failure. We conducted a prospective, observational, first-in-human study of a physician-directed patient self-management system targeting left atrial pressure. METHODS AND RESULTS: Forty patients with reduced or preserved left ventricular ejection fraction and a history of New York Heart Association class III or IV heart failure and acute decompensation were implanted with an investigational left atrial pressure monitor, and readings were acquired twice daily. For the first 3 months, patients and clinicians were blinded as to these readings, and treatment continued per usual clinical assessment. Thereafter, left atrial pressure and individualized therapy instructions guided by these pressures were disclosed to the patient. Event-free survival was determined over a median follow-up of 25 months (range 3 to 38 months). Survival without decompensation was 61% at 3 years, and events tended to be less frequent after the first 3 months (hazard ratio 0.16 [95% confidence interval 0.04 to 0.68], P=0.012). Mean daily left atrial pressure fell from 17.6 mm Hg (95% confidence interval 15.8 to 19.4 mm Hg) in the first 3 months to 14.8 mm Hg (95% confidence interval 13.0 to 16.6 mm Hg; P=0.003) during pressure-guided therapy. The frequency of elevated readings (>25 mm Hg) was reduced by 67% (P<0.001). There were improvements in New York Heart Association class (-0.7+/-0.8, P<0.001) and left ventricular ejection fraction (7+/-10%, P<0.001). Doses of angiotensin-converting enzyme/angiotensin-receptor blockers and beta-blockers were uptitrated by 37% (P<0.001) and 40% (P<0.001), respectively, whereas doses of loop diuretics fell by 27% (P=0.15). CONCLUSIONS: Physician-directed patient self-management of left atrial pressure has the potential to improve hemodynamics, symptoms, and outcomes in advanced heart failure. Clinical Trial Registration Information- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00547729.
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Monitorização Ambulatorial da Pressão Arterial , Insuficiência Cardíaca/terapia , Autocuidado , Antagonistas Adrenérgicos beta/administração & dosagem , Antagonistas Adrenérgicos beta/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Monitorização Ambulatorial da Pressão Arterial/instrumentação , Monitorização Ambulatorial da Pressão Arterial/métodos , Terapia Combinada , Método Duplo-Cego , Eletrodos Implantados , Desenho de Equipamento , Feminino , Átrios do Coração , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Hemodinâmica , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Marca-Passo Artificial , Estudos Prospectivos , Inibidores de Simportadores de Cloreto de Sódio e Potássio/administração & dosagem , Inibidores de Simportadores de Cloreto de Sódio e Potássio/uso terapêuticoRESUMO
Monitoring of HF (heart failure) with intracardiac pressure, intrathoracic impedance and/or natriuretic peptide levels has been advocated. We aimed to investigate possible differences in the response patterns of each of these monitoring modalities during HF decompensation that may have an impact on the potential for early therapeutic intervention. Six sheep were implanted with a LAP (left atrial pressure) sensor and a CRT-D (cardiac resynchronization therapy defibrillator) capable of monitoring impedance along six lead configuration vectors. An estimate of ALAP (LAP from admittance) was determined by linear regression. HF was induced by rapid ventricular pacing at 180 and 220 bpm (beats/min) for a week each, followed by a third week with daily pacing suspensions for increasing durations (1-5 h). Incremental pacing induced progressively severe HF reflected in increases in LAP (5.9 ± 0.4 to 24.5 ± 1.6 mmHg) and plasma atrial (20 ± 3 to 197 ± 36 pmol/l) and B-type natriuretic peptide (3.7 ± 0.7 to 32.7 ± 5.4 pmol/l) (all P<0.001) levels. All impedance vectors decreased in proportion to HF severity (all P<0.001), with the LVring (left ventricular)-case vector correlating best with LAP (r2=0.63, P<0.001). Natriuretic peptides closely paralleled rapid acute changes in LAP during alterations in pacing (P<0.001), whereas impedance changes were delayed relative to LAP. ALAP exhibited good agreement with LAP. In summary, impedance measured with an LV lead correlates significantly with changes in LAP, but exhibits a delayed response to acute alterations. Natriuretic peptides respond rapidly to acute LAP changes. Direct LAP, impedance and natriuretic peptide measurements all show promise as early indicators of worsening HF. ALAP provides an estimate of LAP that may be clinically useful.
Assuntos
Função do Átrio Esquerdo/fisiologia , Insuficiência Cardíaca/diagnóstico , Peptídeos Natriuréticos/sangue , Animais , Biomarcadores/sangue , Estimulação Cardíaca Artificial , Cardiografia de Impedância , Modelos Animais de Doenças , Estudos de Viabilidade , Átrios do Coração/fisiopatologia , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/fisiopatologia , Carneiro DomésticoRESUMO
BACKGROUND: We describe the first human experience with a permanently implantable, direct left atrial pressure (LAP) monitoring system in ambulatory patients with chronic heart failure. METHODS AND RESULTS: Eight patients with established heart failure and at least 1 heart failure hospitalization or unplanned visit for parenteral therapy in the last year underwent device implantation under fluoroscopic guidance. All subjects received aspirin 150 mg and clopidogrel 75 mg daily. Subjects measured LAP twice daily and attended a clinic regularly for data upload and device calibration. Right heart catheterization was performed at the time of device implantation and at 12 weeks. The device was implanted in all subjects with no procedural complications. At the 12-week follow-up, 87% of device LAP measurements were within +/-5 mm Hg of simultaneous pulmonary capillary wedge pressure readings over a wide range of pressures (1.6 to 71 mm Hg). Net drift corrected by calibration was -0.2+/-1.9 mm Hg/mo. During short-term follow-up, there were no device-related complications or systemic emboli. There were no deaths, no unplanned heart failure clinic visits, and no admissions for heart failure. CONCLUSIONS: Ambulatory monitoring of direct LAP with a new implantable device was well tolerated, feasible, and accurate at a short-term follow-up. Further follow-up and investigation are warranted to evaluate the clinical utility of LAP monitoring in patients with heart failure.
Assuntos
Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Monitorização Ambulatorial/instrumentação , Monitorização Ambulatorial/métodos , Próteses e Implantes , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Seguimentos , Átrios do Coração , Humanos , Masculino , Pressão , TransdutoresRESUMO
OBJECTIVES: This was a first-in-human study to assess the feasibility, safety, and exploratory efficacy of interatrial shunting for treating high-risk heart failure (HF) in patients with reduced and preserved ejection fraction. METHODS: A single-arm open-label study of patients with New York Heart Association functional class III or IV HF on optimal therapy was performed at 6 centers. The V-Wave shunt, an hourglass-shaped implant containing a 1-way bioprosthetic valve, was implanted by transseptal catheterization. Clinical, functional, echocardiographic, and hemodynamic evaluations were performed at baseline, 3 and 12 months, and annually (clinical follow-up) thereafter (median follow-up 28 months; interquartile range: 21 to 31 months). RESULTS: A total of 38 patients were enrolled (30 with HF with reduced ejection fraction and 8 with HF with preserved ejection fraction; mean age 66 ± 9 years; 97% and 3% in New York Heart Association functional classes III and IV, respectively), and the shunt device was successfully implanted in all cases without periprocedural mortality. The rate of major device- or procedure-related complications during the first 12 months was 2.6% (periprocedural cardiac tamponade in 1 patient). At 3- and 12-month follow-up, there were improvements in New York Heart Association functional class (classes I and II in 78% and 60% of patients, respectively), quality of life (improvements ≥5 points in 74% and 73% of patients, respectively), and 6-min walk distance (mean increases of 41 ± 63 m and 28 ± 83 m, respectively) (p < 0.02 for all, data available for 36 patients), without changes in objective measures of left- or right-sided function. All shunts were patent at 3 months, but 5 of 36 (14%) had occluded, and another 13 of 36 (36%) were stenotic at the valve by 12 months. Patients with widely patent shunts had lower long-term rates of death, left ventricular assist device placement or heart transplantation (p = 0.001), and HF hospitalization (p = 0.008), along with a reduction of pulmonary capillary wedge pressure (from 23.3 ± 5.4 mm Hg at baseline to 18.0 ± 4.0 mm Hg at 12 months; p = 0.011). CONCLUSIONS: Interatrial shunting with the V-Wave system was feasible and safe in patients with HF with reduced and preserved ejection fraction. Improvements in clinical and functional status were observed early and at 12 months despite attenuation of shunt patency in one-half of the patients. Patients with preserved shunt patency tended to maintain clinical benefit during longer term follow-up. Device modification that improves the durability of patency is likely worthwhile before confirmation of these findings in a randomized trial.
Assuntos
Bioprótese , Cateterismo Cardíaco/instrumentação , Insuficiência Cardíaca/cirurgia , Implante de Prótese de Valva Cardíaca/instrumentação , Próteses Valvulares Cardíacas , Hemodinâmica , Idoso , Canadá , Cateterismo Cardíaco/efeitos adversos , Estudos de Viabilidade , Feminino , Nível de Saúde , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/fisiopatologia , Implante de Prótese de Valva Cardíaca/efeitos adversos , Humanos , Israel , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Desenho de Prótese , Recuperação de Função Fisiológica , Espanha , Volume Sistólico , Fatores de Tempo , Resultado do Tratamento , Função Ventricular EsquerdaRESUMO
BACKGROUND: Implantable cardiac pressure monitors require assurance of calibration. This study evaluated if airway pressure responses during Valsalva maneuver (VM) can be used for calibrating intracardiac pressure transducers. METHODS AND RESULTS: Thirty-eight heart failure patients performed VMs while cardiac and airway pressures were recorded. Patients were designated as Lower (L) if baseline PCW was <20 mm Hg (n = 17); otherwise, they were categorized as Higher (H) (n = 21). VMs were repeated in 9 H patients after nitroglycerin. Procedural success was 92% and there were no complications. Differences between filling pressure and airway pressure (effective pressure) were eliminated during VM (RA(eff) = -0.9 +/- 1.3, RVED(eff) = 1.2 +/- 1.1, PCW(eff) = 2.1 +/- 2.8, and LVED(eff) = 0.9 +/- 1.6 mm Hg), and filling pressures were highly correlated with airway pressure r = 0.94. On average, group H had higher PCW(eff) and LVED(eff) than L patients by 1.8 and 2.5 mm Hg (P < or = .002), respectively, but after nitrates their responses were identical. CONCLUSION: The relationships between cardiac filling pressure and airway pressure during the Valsalva maneuver are sufficiently reliable to be considered as a new, noninvasive method for establishing the calibration of cardiac pressure sensors in patients with heart failure.
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Pressão Sanguínea , Circulação Coronária , Insuficiência Cardíaca/fisiopatologia , Coração/fisiopatologia , Transdutores de Pressão , Idoso , Calibragem , Diástole , Feminino , Insuficiência Cardíaca/terapia , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Pressão , Próteses e Implantes , Pressão Propulsora Pulmonar , Sistema Respiratório/fisiopatologia , Volume Sistólico , Manobra de Valsalva , Função Ventricular EsquerdaRESUMO
BACKGROUND: Fixed drug release kinetics and vessel wall partitioning may limit the effectiveness of drug-eluting stents. We report preliminary experience using a new coronary stent with programmable pharmacokinetics. METHODS AND RESULTS: A newly designed metallic stent contains honeycombed strut elements with inlaid stacked layers of drug and polymer. In vitro studies evaluated recipes for loading paclitaxel to establish the parameters for controlling drug release. Manipulation of the layers of biodegradable polymer and drug allowed varying of the initial 24-hour burst release of paclitaxel from 69% to 8.6% (P<0.0001). Late release of drug could be adjusted dependently or independently of early burst release. A biphasic release profile was created by the addition of blank layers of polymer within the stack. In the 30-day porcine coronary model (n=17 pigs), there was a 70% reduction in late loss (0.3+/-0.5 versus 1.0+/-0.5 mm, P=0.04), a 28% increase in luminal volume (132+/-12 versus 103+/-21 mm(3), P=0.02), and a 50% decrease in histological neointimal area (2.0+/-0.5 versus 4.0+/-1.6 mm(2); P<0.001) compared with bare metal controls. Temporal and regional variations in vascular healing were seen histologically. CONCLUSIONS: Layered polymer/drug inlay stent technology permits flexible and controllable pharmacokinetic profiles. Programmable, complex chemotherapy using this approach may be feasible for the treatment of cardiovascular disease.
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Reestenose Coronária/prevenção & controle , Preparações de Ação Retardada/farmacocinética , Implantes de Medicamento/farmacocinética , Paclitaxel/farmacocinética , Stents , Animais , Divisão Celular/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/farmacocinética , Reestenose Coronária/patologia , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/patologia , Vasos Coronários/cirurgia , Implantes de Medicamento/normas , Desenho de Equipamento , Modelos Animais , Stents/efeitos adversos , Stents/normas , Suínos , Resultado do Tratamento , Túnica Íntima/efeitos dos fármacos , Túnica Íntima/patologia , Ultrassonografia de Intervenção , Grau de Desobstrução Vascular/efeitos dos fármacosAssuntos
Insuficiência Cardíaca , Doença Crônica , Átrios do Coração , Humanos , Próteses e Implantes , Volume SistólicoRESUMO
UNLABELLED: The functional role of various angiographic grades for coronary collaterals remains controversial. The aim of this study was to assess the influence of the Rentrop angiographic grading of coronary collaterals on myocardial perfusion in patients with single-vessel chronic total occlusion (CTO) and no prior myocardial infarction (MI). METHODS: The study included 56 patients with single-vessel CTO and no prior MI who underwent rest-stress myocardial perfusion SPECT and coronary angiography within 6 mo. All patients had angiographic evidence of coronary collaterals. Patients were divided according to the Rentrop classification: Group I had grade 1 or 2 (n = 25) and group II had grade 3 collaterals (n = 31). RESULTS: Group I had a higher frequency of resting regional wall motion abnormalities on left ventriculography (52.6% vs. 19.2% [P = 0.019]). The mean perfusion scores of the overall population showed severe and extensive stress perfusion defects (summed stress score of 14.1 +/- 7.1 and summed difference score of 12.9 +/- 6.9) but minimal resting perfusion defects (summed rest score of 1.0 +/- 2.7). No perfusion scores differed between the 2 groups. The perfusion findings suggested that chronic stunning rather than hibernation is the principal cause of regional wall motion abnormalities in these patients. CONCLUSION: In the setting of single-vessel CTO and no prior MI, coronary collaterals appear to protect against resting perfusion defects. Excellent angiographic collaterals may prevent resting regional wall motion abnormalities but do not appear to protect against stress-induced perfusion defects.
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Circulação Colateral , Angiografia Coronária , Estenose Coronária/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Disfunção Ventricular Esquerda/diagnóstico por imagem , Idoso , Doença Crônica , Estenose Coronária/complicações , Feminino , Coração/diagnóstico por imagem , Humanos , Técnicas In Vitro , Masculino , Infarto do Miocárdio/diagnóstico por imagem , Cintilografia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Disfunção Ventricular Esquerda/etiologiaRESUMO
A left atrial pressure (LAP) monitoring system was developed for guiding the management of patients with heart failure. The LAP sensor is implanted into the left atrium via transseptal catheterization and affixed to the interatrial septum by nitinol anchors. The long-term safety of permanent implantation of the LAP sensor in patients was evaluated based on the comparative pathology in animals. Tissue specimens of the LAP sensor from 7 patients, 49 canines, and 14 ovine were examined for thrombosis and tissue overgrowth. Implant duration ranged from 22 to 1,686 days. Gross examination showed minimal-to-moderate tissue overgrowth with no evidence of migration, erosion, or perforation. There was no excessive host-to-device reaction or active thrombogenesis in any of the subjects that followed the antithrombotic therapy protocol. Micro-computed tomography scanning confirmed the structural integrity of the device. Low vacuum scanning electron microscopy and histology showed neoendocardial tissue overgrowth with no inflammation or fibrin. The pathology of both animal models was found to closely approximate the pathology in humans and favorably supports the long-term safety of the device.
Assuntos
Pressão Atrial , Átrios do Coração/patologia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Transdutores de Pressão , Animais , Artefatos , Cães , Falha de Equipamento , Insuficiência Cardíaca/terapia , Humanos , Microscopia Eletrônica de Varredura , Modelos Animais , Segurança do Paciente , Pressão , Ovinos , Trombose/fisiopatologia , Fatores de Tempo , Microtomografia por Raio-XAssuntos
Estenose Coronária/complicações , Monitorização Fisiológica/instrumentação , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/fisiopatologia , Próteses e Implantes , Idoso , Idoso de 80 Anos ou mais , Átrios do Coração , Humanos , Masculino , Isquemia Miocárdica/etiologia , Pressão , TransdutoresRESUMO
OBJECTIVES: This study sought to determine the accuracy of Doppler echocardiography and tissue Doppler imaging (TDI) measurements in detecting elevated left atrial pressure (LAP) in ambulant subjects with chronic heart failure using directly measured LAP as the reference. BACKGROUND: Echocardiographic indexes including the ratio of transmitral to annular early diastolic velocities (E/e') may identify raised invasively measured left ventricular filling pressures when tested in cross-sectional studies in some populations. The accuracy of these indexes when measured sequentially remains untested. We determined the accuracy of Doppler echocardiography and TDI measurements in detecting elevated directly measured LAP in ambulant subjects with stable chronic heart failure. METHODS: Fifteen patients with New York Heart Association functional class II to III heart failure and a permanently implanted direct LAP monitoring device underwent serial echocardiography. Simultaneous resting mean LAP, Doppler mitral inflow, mitral annular TDI, and pulmonary venous inflow velocities were obtained on each occasion. Receiver-operator characteristic curve analysis was used to compare the accuracy of the Doppler variables to detect an elevated device LAP ≥15 and ≥20 mm Hg. RESULTS: The patients (13 men, mean age: 71 years, mean left ventricular ejection fraction: 32 ± 12%) underwent 60 simultaneous echocardiographic studies and LAP measurements with a median of 4 (1 to 7) studies per patient. Mean LAP was 16.9 (range 5 to 39 mm Hg) at echocardiography (n = 60). E/e' had the greatest accuracy for detection of LAP ≥15 mm Hg with an area beneath the receiver-operator characteristic curve >0.9. In comparison, area under the curve for mitral E velocity and mitral E/A were 0.77 and 0.76, respectively (p < 0.008 vs. E/e' medial and average). CONCLUSIONS: Single and serial measurements of mitral inflow and mitral annular TDI velocities (E/e') can reliably detect raised directly measured LAP in ambulant subjects with compensated chronic heart failure. (Hemodynamically Guided Home Self-Therapy in Severe Heart Failure Patients [HOMEOSTASIS]; NCT00547729).
Assuntos
Função do Átrio Esquerdo , Ecocardiografia Doppler , Insuficiência Cardíaca/diagnóstico por imagem , Valva Mitral/diagnóstico por imagem , Monitorização Ambulatorial , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Feminino , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Valva Mitral/fisiopatologia , Monitorização Ambulatorial/instrumentação , Valor Preditivo dos Testes , Pressão , Curva ROC , Volume Sistólico , Fatores de Tempo , Função Ventricular EsquerdaRESUMO
We report the stability, accuracy, and development history of a new left atrial pressure (LAP) sensing system in ambulatory heart failure (HF) patients. A total of 84 patients with advanced HF underwent percutaneous transseptal implantation of the pressure sensor. Quarterly noninvasive calibration by modified Valsalva maneuver was achieved in all patients, and 96.5% of calibration sessions were successful with a reproducibility of 1.2 mmHg. Absolute sensor drift was maximal after 3 months at 4.7 mmHg (95% CI, 3.2-6.2 mmHg) and remained stable through 48 months. LAP was highly correlated with simultaneous pulmonary wedge pressure at 3 and 12 months (r = 0.98, average difference of 0.8 ± 4.0 mmHg). Freedom from device failure was 95% (n = 37) at 2 years and 88% (n = 12) at 4 years. Causes of failure were identified and mitigated with 100% freedom from device failure and less severe anomalies in the last 41 consecutive patients (p = 0.005). Accurate and reliable LAP measurement using a chronic implanted monitoring system is safe and feasible in patients with advanced heart failure.
Assuntos
Função do Átrio Esquerdo , Eletrodos Implantados , Insuficiência Cardíaca/diagnóstico , Testes de Função Cardíaca/instrumentação , Monitorização Ambulatorial/instrumentação , Transdutores de Pressão , Austrália , Calibragem , Eletrodos Implantados/normas , Desenho de Equipamento , Falha de Equipamento , Insuficiência Cardíaca/fisiopatologia , Testes de Função Cardíaca/normas , Hemodinâmica , Humanos , Estimativa de Kaplan-Meier , Monitorização Ambulatorial/normas , Nova Zelândia , Valor Preditivo dos Testes , Pressão , Estudos Prospectivos , Pressão Propulsora Pulmonar , Sistema de Registros , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Processamento de Sinais Assistido por Computador , Fatores de Tempo , Transdutores de Pressão/normas , Estados Unidos , Manobra de ValsalvaRESUMO
OBJECTIVES AND BACKGROUND: The purpose of this study was to determine the effectiveness and vascular response of a pimecrolimus drug eluting stent and a combination (pimecrolimus + paclitaxel) stent as compared with bare metal controls in the porcine coronary model. METHODS AND RESULTS: In the first phase of the study, cobalt chromium stents were loaded with an erodible polymer and either a slow release or a fast release formulation of pimecrolimus. Thirty stents (metal, n = 10; pimecrolimus slow, n = 10; pimecrolimus fast, n = 10) were implanted in the coronary arteries of 10 pigs. At 30 days, neointimal proliferation and inflammation were both significantly less in the pimecrolimus fast release group as compared with the bare metal controls. Endothelialization was complete and equal in all three groups of stents. In the second phase of the study, stents were loaded with an erodible polymer with alternating reservoirs of paclitaxel and pimecrolimus. Twenty stents (8 control stents and 12 dual stents) were implanted in the coronary arteries of seven pigs. At 30 days, neointimal proliferation was significantly less in the dual drug group as compared with the bare metal controls. Endothelialization was complete in both groups of stents, suggesting complete healing of the arteries. CONCLUSIONS: In a 30-day porcine stent model, pimecrolimus inhibits neointimal proliferation as compared with bare metal stents. Also, the proof of concept of a dual drug eluting stent was established showing both safety and efficacy.