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Willixhofer R, Rettl R, Kronberger C, Ermolaev N, Gregshammer B, Duca F, Binder C, Kammerlander A, Alasti F, Kastner J, Bonderman D, Bergler-Klein J, Agostoni P, Badr Eslam R. Cardiopulmonary exercise testing in transthyretin amyloid cardiomyopathy patients: a long-term follow-up study. J Cardiovasc Med (Hagerstown) 2024:01244665-990000000-00231. [PMID: 39012655 DOI: 10.2459/jcm.0000000000001636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/17/2024]
Abstract
AIMS Patients with transthyretin amyloid cardiomyopathy (ATTR-CM) experience reduced functional capacity. We evaluated changes in functional capacity over extensive follow-up using cardiopulmonary exercise testing (CPX). METHODS ATTR-CM patients underwent CPX and blood testing at baseline, first [V1, 8 (6-10) months] and second follow-up (V2) at 35 (26-41) months after start of disease-specific therapy. RESULTS We included 34 ATTR-CM patients, aged 77 (±6) years (88.2% men). CPX showed two patterns with functional capacity improvement at V1 and deterioration at V2. Peak work capacity (P = 0.005) and peak oxygen consumption (VO2, P = 0.012) increased at V1 compared with baseline and decreased at V2. The ventilation to carbon dioxide relationship slope (VE/VCO2) increased at V2 compared with baseline and V1 (P = 0.044). A cut-off for peak VO2 at 14 ml/kg·min showed more events (composite of death and heart failure hospitalization): less than 14 vs. greater than 14 ml/kg·min (P = 0.013). Cut-offs for VE/VCO2 slope at 40 showed more events greater than 40 vs. less than 40 (P = 0.009). CONCLUSION ATTR-CM patients showed an improvement and deterioration in the short-term and long-term follow-up, respectively, with a better prognosis for those with peak VO2 above 14 ml/kg·min and for a VE/VCO2 slope below 40.
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Affiliation(s)
- Robin Willixhofer
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna
| | - René Rettl
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna
| | - Christina Kronberger
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna
| | - Nikita Ermolaev
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna
| | - Bernhard Gregshammer
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna
| | - Franz Duca
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna
| | - Christina Binder
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna
| | - Andreas Kammerlander
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna
| | - Farideh Alasti
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna
| | - Johannes Kastner
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna
| | | | - Jutta Bergler-Klein
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna
| | - Piergiuseppe Agostoni
- Centro Cardiologico Monzino, IRCCS
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Roza Badr Eslam
- Division of Cardiology, Department of Internal Medicine II, Medical University of Vienna
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Patel RK, Bandera F, Venneri L, Porcari A, Razvi Y, Ioannou A, Chacko L, Martinez-Naharro A, Rauf MU, Knight D, Brown J, Petrie A, Wechalekar A, Whelan C, Lachmann H, Muthurangu V, Guazzi M, Hawkins PN, Gillmore JD, Fontana M. Cardiopulmonary Exercise Testing in Evaluating Transthyretin Amyloidosis. JAMA Cardiol 2024; 9:367-376. [PMID: 38446436 PMCID: PMC10918582 DOI: 10.1001/jamacardio.2024.0022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 12/26/2023] [Indexed: 03/07/2024]
Abstract
Importance Cardiopulmonary exercise testing (CPET) has an established role in the assessment of patients with heart failure. However, data are lacking in patients with transthyretin (ATTR) amyloidosis. Objective To use CPET to characterize the spectrum of functional phenotypes in patients with ATTR amyloidosis and assess their association with the cardiac amyloid burden as well as the association between CPET parameters and prognosis. Design, Setting and Participants This single-center study evaluated patients diagnosed with ATTR amyloidosis from May 2019 to September 2022 who underwent CPET at the National Amyloidosis Centre. Of 1045 patients approached, 506 were included and completed the study. Patients were excluded if they had an absolute contraindication to CPET or declined participation. The mean (SD) follow-up period was 22.4 (11.6) months. Main Outcomes and Measures Comparison of CPET parameters across disease phenotypes (ATTR with cardiomyopathy [ATTR-CM], polyneuropathy, or both [ATTR-mixed]), differences in CPET parameters based on degree of amyloid infiltration (as measured by cardiovascular magnetic resonance [CMR] with extracellular volume mapping), and association between CPET parameters and prognosis. Results Among the 506 patients with ATTR amyloidosis included in this study, the mean (SD) age was 73.5 (10.2) years, and 457 participants (90.3%) were male. Impairment in functional capacity was highly prevalent. Functional impairment in ATTR-CM and ATTR-mixed phenotypes (peak mean [SD] oxygen consumption [VO2], 14.5 [4.3] mL/kg/min and 15.7 [6.2] mL/kg/min, respectively) was observed alongside impairment in the oxygen pulse, with ventilatory efficiency highest in ATTR-CM (mean [SD] ventilatory efficiency/volume of carbon dioxide expired slope, 38.1 [8.6]). Chronotropic incompetence and exercise oscillatory ventilation (EOV) were highly prevalent across all phenotypes, with both the prevalence and severity being higher than in heart failure from different etiologies. Worsening of amyloid burden on CMR was associated with decline in multiple CPET parameters, although chronotropic response and EOV remained abnormal irrespective of amyloid burden. On multivariable Cox regression analysis, peak VO2 and peak systolic blood pressure (SBP) were independently associated with prognosis (peak VO2: hazard ratio, 0.89 [95% CI, 0.81-0.99; P = .03]; peak SBP: hazard ratio, 0.98 [95% CI, 0.97-0.99; P < .001]). Conclusions and Relevance In this study, ATTR amyloidosis was characterized by distinct patterns of functional impairment between all disease phenotypes. A high prevalence of chronotropic incompetence, EOV, and ventilatory inefficiency were characteristic of this population. CPET parameters were associated with amyloid burden by CMR and with peak VO2, and SBP, which have been shown to be independent predictors of mortality. These findings suggest that CPET may be useful in characterizing distinct patterns of functional impairment across the spectrum of amyloid infiltration and predicting outcomes, and potentially offers a more comprehensive method of evaluating functional capacity for future prospective studies.
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Affiliation(s)
- Rishi K. Patel
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - Francesco Bandera
- Cardiac Rehabilitation and Heart Failure Unit, Cardiology University Department, Scientific Institute for Research, Hospitalization and Healthcare MultiMedica, Sesto San Giovanni, Milan, Italy
- Department of Biomedical Sciences for Health, University of Milano, Milan, Italy
| | - Lucia Venneri
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - Aldostefano Porcari
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
- Center for Diagnosis and Treatment of Cardiomyopathies, Cardiovascular Department, Azienda Sanitaria Universitaria Giuliano-Isontina, University of Trieste, Italy, Trieste, Italy
| | - Yousuf Razvi
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - Adam Ioannou
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - Liza Chacko
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - Ana Martinez-Naharro
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - Muhammad U. Rauf
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - Daniel Knight
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - James Brown
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - Aviva Petrie
- Eastman Dental Institute, University College London, University Street, London, United Kingdom
| | - Ashutosh Wechalekar
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - Carol Whelan
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - Helen Lachmann
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - Vivek Muthurangu
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Marco Guazzi
- Cardiac Rehabilitation and Heart Failure Unit, Cardiology University Department, Scientific Institute for Research, Hospitalization and Healthcare MultiMedica, Sesto San Giovanni, Milan, Italy
- Department of Biomedical Sciences for Health, University of Milano, Milan, Italy
| | - Philip N. Hawkins
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - Julian D. Gillmore
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
| | - Marianna Fontana
- National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, London, United Kingdom
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3
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Soman P, Azhar AZ. Determining the Natural History of a Rare Disease: A Narrow Window of Opportunity. Can J Cardiol 2024; 40:370-371. [PMID: 38141812 DOI: 10.1016/j.cjca.2023.11.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 11/19/2023] [Indexed: 12/25/2023] Open
Affiliation(s)
- Prem Soman
- Division of Cardiology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
| | - Abdullah Zoheb Azhar
- Division of Cardiology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
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Argirò A, Silverii MV, Burgisser C, Fattirolli F, Baldasseroni S, di Mario C, Zampieri M, Biagioni G, Mazzoni C, Chiti C, Allinovi M, Ungar A, Perfetto F, Cappelli F. Serial Changes in Cardiopulmonary Exercise Testing Parameters in Untreated Patients With Transthyretin Cardiac Amyloidosis. Can J Cardiol 2024; 40:364-369. [PMID: 37793568 DOI: 10.1016/j.cjca.2023.09.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/08/2023] [Accepted: 09/27/2023] [Indexed: 10/06/2023] Open
Abstract
BACKGROUND Transthyretin amyloid cardiomyopathy (ATTR-CM) is associated with a progressive reduction of functional capacity. The progression of cardiopulmonary exercise testing (CPET) parameters over time is still unknown. METHODS In this study, 55 patients with ATTR-CM underwent 2 serial cardiologic evaluations and CPETs in a national referral center for cardiac amyloidosis (Careggi University Hospital, Florence). RESULTS Forty-three patients (78%) had wild-type ATTR. Median age was 80 years (interquartile range [IQR] 76-83 years), and 50 of the patients (91%) were men. At baseline, median peak oxygen consumption (pVO2) was 15 mL/kg/min (IQR 12-18 mL/kg/min), percentage of predicted pVO2 (%ppVO2) was 71% (IQR 60%-83%) and VE/VCO2 slope was 31 (IQR 26-34). After a median follow-up of 14 months (IQR 13-16 months), pVO2, %ppVO2 and VE/VCO2 slope were significantly worsened (-1.29 mL/kg/min [95% confidence interval (CI): -1.85 to -0.74; P < 0.01], -4.5% [95% CI: -6.9 to -2.02; P < 0.01], and 8.6 [95% CI 6-11; P < 0.01], respectively). Furthermore, exercise time (-39 s, 95% CI: -59 to -19; P < 0.01), exercise tolerance (-0.47 metabolic equivalents, 95% CI: -0.69 to -0.2; P < 0.01), and peak systolic pressure (-10.8 mm Hg, 95% CI: -16.2 to -5.4; P < 0.01) were significantly reduced. The worsening in CPET variables did not correspond with a significant change in echocardiographic parameters. CONCLUSIONS Cardiorespiratory response to exercise significantly worsened over a short period of time in patients with ATTR-CM. Serial CPET may be useful to identify early disease progression.
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Affiliation(s)
- Alessia Argirò
- Tuscan Regional Amyloidosis Centre, Careggi University Hospital, Florence, Italy
| | - Maria Vittoria Silverii
- Cardiac Rehabilitation Unit, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Costanza Burgisser
- Cardiac Rehabilitation Unit, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Francesco Fattirolli
- Cardiac Rehabilitation Unit, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Samuele Baldasseroni
- Division of Interventional Structural Cardiology, Cardiothoracovascular Department, Careggi University Hospital, Florence, Italy
| | - Carlo di Mario
- Division of Interventional Structural Cardiology, Cardiothoracovascular Department, Careggi University Hospital, Florence, Italy
| | - Mattia Zampieri
- Tuscan Regional Amyloidosis Centre, Careggi University Hospital, Florence, Italy.
| | - Giulia Biagioni
- Tuscan Regional Amyloidosis Centre, Careggi University Hospital, Florence, Italy
| | - Carlotta Mazzoni
- Tuscan Regional Amyloidosis Centre, Careggi University Hospital, Florence, Italy
| | - Chiara Chiti
- Tuscan Regional Amyloidosis Centre, Careggi University Hospital, Florence, Italy
| | - Marco Allinovi
- Tuscan Regional Amyloidosis Centre, Careggi University Hospital, Florence, Italy
| | - Andrea Ungar
- Cardiac Rehabilitation Unit, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Federico Perfetto
- Tuscan Regional Amyloidosis Centre, Careggi University Hospital, Florence, Italy
| | - Francesco Cappelli
- Tuscan Regional Amyloidosis Centre, Careggi University Hospital, Florence, Italy
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Zhong W, Liu R, Cheng H, Xu L, Wang L, He C, Wei Q. Longer-Term Effects of Cardiac Telerehabilitation on Patients With Coronary Artery Disease: Systematic Review and Meta-Analysis. JMIR Mhealth Uhealth 2023; 11:e46359. [PMID: 37505803 PMCID: PMC10422170 DOI: 10.2196/46359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 06/19/2023] [Accepted: 07/03/2023] [Indexed: 07/29/2023] Open
Abstract
BACKGROUND Cardiac telerehabilitation offers a flexible and accessible model for patients with coronary artery disease (CAD), effectively transforming the traditional cardiac rehabilitation (CR) approach. OBJECTIVE This systematic review and meta-analysis aimed to evaluate the long-term effectiveness of cardiac telerehabilitation. METHODS We searched randomized controlled trials (RCTs) in 7 electronic databases: PubMed, Web of Science, EMBASE, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, the China National Knowledge Infrastructure, and WANFANG. The primary outcome focused on cardiopulmonary fitness. For secondary outcomes, we examined cardiovascular risk factors (blood pressure, BMI, and serum lipids), psychological scales of depression and anxiety, quality of life (QoL), cardiac telerehabilitation adherence, and adverse events. RESULTS In total, 10 RCTs fulfilled the predefined criteria, which were reviewed in our meta-analysis. The results showed that after cardiac telerehabilitation, there was a significant difference in the improvement in long-term peak oxygen uptake compared to center-based CR (mean difference [MD] 1.61, 95% CI 0.38-2.85, P=.01), particularly after 6-month rehabilitation training (MD 1.87, 95% CI 0.34-3.39, P=.02). The pooled effect size of the meta-analysis indicated that there were no significant differences in the reduction in cardiovascular risk factor control. There was also no practical demonstration of anxiety scores or depression scores. However, cardiac telerehabilitation demonstrated an improvement in the long-term QoL of patients (MD 0.92, 95% CI 0.06-1.78, P=.04). In addition, the study reported a high completion rate (80%) for cardiac telerehabilitation interventions. The incidence of adverse events was also low during long-term follow-up. CONCLUSIONS Cardiac telerehabilitation proves to be more effective in improving cardiopulmonary fitness and QoL during the long-term follow-up for patients with CAD. Our study highlights monitoring-enabled and patient-centered telerehabilitation programs, which play a vital role in the recovery and development of CAD and in the long-term prognosis of patients.
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Affiliation(s)
- Wen Zhong
- Department of Rehabilitation Medicine and Institute of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, Chengdu, Sichuan, China
| | - Rui Liu
- Department of Rehabilitation Medicine and Institute of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, Chengdu, Sichuan, China
| | - Hongxin Cheng
- Department of Rehabilitation Medicine and Institute of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, Chengdu, Sichuan, China
| | - Lin Xu
- Department of Rehabilitation Medicine and Institute of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, Chengdu, Sichuan, China
| | - Lu Wang
- Department of Rehabilitation Medicine and Institute of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, Chengdu, Sichuan, China
| | - Chengqi He
- Department of Rehabilitation Medicine and Institute of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, Chengdu, Sichuan, China
| | - Quan Wei
- Department of Rehabilitation Medicine and Institute of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, Chengdu, Sichuan, China
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Scirpa R, Cittadini E, Mazzocchi L, Tini G, Sclafani M, Russo D, Imperatrice A, Tropea A, Autore C, Musumeci B. Risk stratification in transthyretin-related cardiac amyloidosis. Front Cardiovasc Med 2023; 10:1151803. [PMID: 37025682 PMCID: PMC10070959 DOI: 10.3389/fcvm.2023.1151803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 03/06/2023] [Indexed: 04/08/2023] Open
Abstract
Transthyretin related cardiac amyloidosis (TTR-CA) is an infiltrative cardiomyopathy that cause heart failure with preserved ejection fraction, mainly in aging people. Due to the introduction of a non invasive diagnostic algorithm, this disease, previously considered to be rare, is increasingly recognized. The natural history of TTR-CA includes two different stages: a presymptomatic and a symptomatic stage. Due to the availability of new disease-modifying therapies, the need to reach a diagnosis in the first stage has become impelling. While in variant TTR-CA an early identification of the disease may be obtained with a genetic screening in proband's relatives, in the wild-type form it represents a challenging issue. Once the diagnosis has been made, in order to identifying patients with a higher risk of cardiovascular events and death it is necessary to focus on risk stratification. Two prognostic scores have been proposed both based on biomarkers and laboratory findings. However, a multiparametric approach combining information from electrocardiogram, echocardiogram, cardiopulmonary exercise test and cardiac magnetic resonance may be warranted for a more comprehensive risk prediction. In this review, we aim at evaluating a step by step risk stratification, providing a clinical diagnostic and prognostic approach for the management of patients with TTR-CA.
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Affiliation(s)
- Riccardo Scirpa
- Division of Cardiology, Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Edoardo Cittadini
- Division of Cardiology, Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Lorenzo Mazzocchi
- Division of Cardiology, Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Giacomo Tini
- Division of Cardiology, Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy
- Department of Cardiology, IRCCS San Raffaele Pisana, Rome, Italy
| | - Matteo Sclafani
- Division of Cardiology, Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Domitilla Russo
- Division of Cardiology, Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Andrea Imperatrice
- Division of Cardiology, Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Alessandro Tropea
- Division of Cardiology, Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | | | - Beatrice Musumeci
- Division of Cardiology, Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy
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Monfort A, Thevenet E, Lacavalerie MR, Banydeen R, Inamo J, Neviere R. Determinants of ventilatory inefficiency in transthyretin cardiac amyloidosis: The role of excessive ventilatory drive. Front Physiol 2022; 13:1002238. [DOI: 10.3389/fphys.2022.1002238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 10/11/2022] [Indexed: 11/13/2022] Open
Abstract
Background and objective: Along with impaired aerobic capacity, increased slope of the relationship between ventilation (VE) and pulmonary CO2 output (VCO2), i.e., VE-VCO2 slope is a common finding in patients with cardiac amyloidosis (CA), which suggests ventilatory inefficiency. Little is known about mechanisms leading to ventilatory inefficiency in CA patients. The purpose of this investigation was to examine the factors that underlie the abnormal ventilatory efficiency in transthyretin hereditary CA patients, such as excessive ventilatory drive, inability of pulmonary blood flow to increase adequately during exercise and excessive sympathetic stimulation, which are known mechanisms of VE-VCO2 slope increase.Methods: In this single-center retrospective observational study, consecutive patients (n = 41) with known familial transthyretin amyloidosis p.Val142Ile mutation carriers with confirmed cardiac phenotype were included.Results: Compared with CA patients without ventilatory inefficiency (VE-VCO2 slope < 36), patients with ventilatory inefficiency (VE-VCO2 slope ≥ 36) had increased inter-ventricular septum thickness, lower VO2 peak along with hyperventilation, and prolonged post-exercise heart rate recovery. By multivariate analysis, only excess of minute-ventilation at anaerobic threshold (β = 0.127; p = 0.011) remained an independent predictor of ventilatory inefficiency.Conclusion: Our data suggest that high ventilatory stimulation during exercise leading to hyperventilation is the main determinant of ventilatory inefficiency in hereditary transthyretin cardiac amyloidosis patients. This novel finding helps to better understand the mechanism of exercise intolerance in these patients where physiological limitation may be related to both heart dysfunction and abnormal pulmonary response.
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