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1.
Radiology ; 291(2): 340-348, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30888934

RESUMO

Background Patient preference is pivotal for widespread adoption of tests in clinical practice. Patient preferences for invasive versus other noninvasive tests for coronary artery disease are not known. Purpose To compare patient acceptance and preferences for noninvasive and invasive cardiac imaging in North and South America, Asia, and Europe. Materials and Methods This was a prospective 16-center trial in 381 study participants undergoing coronary CT angiography with stress perfusion, SPECT, and invasive coronary angiography (ICA). Patient preferences were collected by using a previously validated questionnaire translated into eight languages. Responses were converted to ordinal scales and were modeled with generalized linear mixed models. Results In patients in whom at least one test was associated with pain, CT and SPECT showed reduced median pain levels, reported on 0-100 visual analog scales, from 20 for ICA (interquartile range [IQR], 4-50) to 6 for CT (IQR, 0-27.5) and 5 for SPECT (IQR, 0-25) (P < .001). Patients from Asia reported significantly more pain than patients from other continents for ICA (median, 25; IQR, 10-50; P = .01), CT (median, 10; IQR, 0-30; P = .02), and SPECT (median, 7; IQR, 0-28; P = .03). Satisfaction with preparation differed by continent and test (P = .01), with patients from Asia reporting generally lower ratings. Patients from North America had greater percentages of "very high" or "high" satisfaction than patients from other continents for ICA (96% vs 82%, respectively; P < .001) and SPECT (95% vs 79%, respectively; P = .04) but not for CT (89% vs 86%, respectively; P = .70). Among all patients, CT was preferred by 54% of patients, compared with 18% for SPECT and 28% for ICA (P < .001). Conclusion For cardiac imaging, patients generally favored CT angiography with stress perfusion, while study participants from Asia generally reported lowest satisfaction. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Woodard and Nguyen in this issue.

2.
Int J Cardiol ; 267: 208-214, 2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-29685695

RESUMO

BACKGROUND: Computed tomography coronary angiography (CTCA) image analysis enables plaque characterization and non-invasive fractional flow reserve (FFR) calculation. We analyzed various parameters derived from CTCA images and evaluated their associations with ischemia. METHODS: 49 (61 lesions) patients underwent CTCA and invasive FFR. Lesions with diameter stenosis (DS) ≥ 50% were considered obstructive. CTCA image processing incorporating analytical and numerical methods were used to quantify anatomical parameters of lesion length (LL) and minimum lumen area (MLA); plaque characteristic parameters of plaque volume, low attenuation plaque (LAP) volume, dense calcium volume (DCV), normalized plaque volume (NP Vol), plaque burden, eccentricity index and napkin-ring (NR) sign; and hemodynamic parameters of resistance index, stenosis flow reserve (SFR) and FFRB. Ischemia was defined as FFR ≤ 0.8. RESULTS: Plaque burden and plaque volume were inversely related to FFR. Multivariable logistic regression analysis identified the best anatomical, plaque and hemodynamic predictors, respectively, as DS (≥50% vs <50%; OR: 8.0; 95% CI: 1.6-39.4), normalized plaque volume (NP Vol) (≥4.3 vs <4.3; OR: 3.9; 95% CI: 1.1-14.0) and NR Sign (0 vs 1; OR: 13.6; 95% CI: 1.3-146.1), and FFRB (≤0.8 vs >0.8; OR: 44.4; 95% CI: 8.8-224.8). AUC increased from 0.70 with DS as the sole predictor to 0.81 after adding NP Vol and NR Sign; further addition of FFRB increased AUC to 0.93. CONCLUSION: Normalized plaque volume, napkin-ring derived from plaque analysis, and FFRB from numerical simulations on CTCA images substantially improved discrimination of ischemic lesions, compared to assessment by DS alone.

3.
Ann Acad Med Singapore ; 47(2): 56-62, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29549371

RESUMO

INTRODUCTION: Patients referred for chest pain from primary care have increased, along with demand for outpatient cardiology consultations. We evaluated 'Triage Protocol' that implements standardised diagnostic testing prior to patients' first cardiology consultation. MATERIALS AND METHODS: Under the 'Triage Protocol', patients referred for chest pain were pretriaged using a standardised algorithm and subsequently referred for relevant functional diagnostic cardiology tests before their initial cardiology consultation. At the initial cardiology consultation scheduled by the primary care provider, test results were reviewed. A total of 522 triage patients (mean age 55 ± 13, male 53%) were frequency-matched by age, gender and risk cohort to 289 control patients (mean age: 56 ± 11, male: 52%). Pretest risk of coronary artery disease was defined according to a Modified Duke Clinical Score (MDCS) as low (<10), intermediate (10-20) and high (>20). The primary outcome was time from referral to diagnosis (days). Secondary outcomes were total visits, discharge rate at first consultation, patient cost and adverse cardiac outcomes. RESULTS: The 'Triage Protocol' resulted in shorter times from referral to diagnosis (46 vs 131 days; P <0.0001) and fewer total visits (2.4 vs 3.0; P <0.0001). However, triage patients in low-risk groups experienced higher costs due to increased testing (S$421 vs S$357, P = 0.003). Adverse cardiac event rates under the 'Triage Protocol' indicated no compromise to patient safety (triage vs control: 0.57% vs 0.35%; P = 1.000). CONCLUSION: By implementing diagnostic cardiac testing prior to patients' first specialist consultation, the 'Triage Protocol' expedited diagnosis and reduced subsequent visits across all risk groups in ambulatory chest pain patients.


Assuntos
Serviço Hospitalar de Cardiologia , Dor no Peito/terapia , Triagem/métodos , Algoritmos , Protocolos Clínicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Atenção Primária à Saúde , Resultado do Tratamento
4.
PLoS Biol ; 16(2): e2004285, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29485983

RESUMO

The use of consumer-grade wearables for purposes beyond fitness tracking has not been comprehensively explored. We generated and analyzed multidimensional data from 233 normal volunteers, integrating wearable data, lifestyle questionnaires, cardiac imaging, sphingolipid profiling, and multiple clinical-grade cardiovascular and metabolic disease markers. We show that subjects can be stratified into distinct clusters based on daily activity patterns and that these clusters are marked by distinct demographic and behavioral patterns. While resting heart rates (RHRs) performed better than step counts in being associated with cardiovascular and metabolic disease markers, step counts identified relationships between physical activity and cardiac remodeling, suggesting that wearable data may play a role in reducing overdiagnosis of cardiac hypertrophy or dilatation in active individuals. Wearable-derived activity levels can be used to identify known and novel activity-modulated sphingolipids that are in turn associated with insulin sensitivity. Our findings demonstrate the potential for wearables in biomedical research and personalized health.

5.
Heart Lung Circ ; 27(7): 853-855, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28887110

RESUMO

BACKGROUND: The left ventricular assist device (LVAD) has revolutionised our treatment of advanced stage heart failure, giving debilitated patients a new lease on life. A small proportion of these LVAD patients can be bridged-to-recovery. The identification of these patients and decision to wean, however, can be challenging. METHODS: The need to fully explant the device upon recovery has evolved to a minimalist approach aiming to avoid injury to the 'recovered' heart. A review of the evolution of explant strategies was performed to guide our decision to wean the LVAD in our early experience. RESULTS: Between 2009 and 2014, two patients in our series of 69 LVAD implants (2.9%) were successfully weaned off their LVADs. The second patient had a minimal access implantation of his HeartWare Ventricular Assist Device (HVAD, Medtronic Inc, Framingham, MA, USA). His clinical variables and minimalist weaning strategy are described. CONCLUSIONS: A case of LVAD decommissioning by thrombosis of the outflow graft, using percutaneous Amplatzer Vascular Plug II (St. Jude Medical, St. Paul, MN, USA) without surgery is reported.


Assuntos
Remoção de Dispositivo/métodos , Insuficiência Cardíaca/terapia , Ventrículos do Coração/fisiopatologia , Coração Auxiliar/efeitos adversos , Recuperação de Função Fisiológica , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Falha de Prótese
7.
Clin Cardiol ; 40(11): 1008-1012, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28683177

RESUMO

BACKGROUND: Exercise prescription for patients with cardiovascular disease remains a challenge. The concept of exercising at an intensity equivalent to one's anaerobic threshold has been well studied and highly recommended in the fitness industry for other populations. For this concept to be applicable to patients with cardiovascular disease, the level and intensity of activity must not trigger myocardial ischemia. HYPOTHESIS: We hypothesized that the heart rate at ventilatory anaerobic threshold (HRVAT ) will not exceed heart rate at ischemic threshold (HRIT ) (ie, HRVAT ≤ HRIT in a majority [>50%] of patients). METHODS: In this retrospective pilot study, 19 patients, mean age at baseline of 45.0 ± 15.6 years, who had positive cardiopulmonary exercise stress testing were included. Heart rate at ventilatory anaerobic threshold (VAT) was derived from a computer-analyzed V-slope method. The ischemic threshold (IT) was determined from electrocardiogram. The exercise test parameters at VAT in relation to IT were examined. RESULTS: Heart rate at VAT preceded heart rate at IT in 89.5% of patients. On average, achievement of VAT preceded IT relative to workload (119.5 ± 49.6 vs 132.6 ± 47.5; P < 0.01), heart rate (121.2 ± 15.9 vs 133.3 ± 17.5; P < 0.01), oxygen consumption (19.3 ± 4.9 vs 20.8 ± 3.7; P < 0.01), and respiratory exchange ratio (0.96 ± 0.10 vs 1.01 ± 0.07; P < 0.01). CONCLUSIONS: Greater than 50% of patients met the criteria of HRVAT ≤ HRIT ; therefore, we propose that anaerobic threshold is a suitable target aerobic exercise heart rate for all patients with cardiovascular diseases indicated for cardiopulmonary rehabilitation.


Assuntos
Reabilitação Cardíaca/métodos , Terapia por Exercício/métodos , Tolerância ao Exercício , Cardiopatias/reabilitação , Frequência Cardíaca , Adulto , Limiar Anaeróbio , Reabilitação Cardíaca/efeitos adversos , Eletrocardiografia , Teste de Esforço , Terapia por Exercício/efeitos adversos , Feminino , Cardiopatias/diagnóstico , Cardiopatias/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Projetos Piloto , Ventilação Pulmonar , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
8.
Radiology ; 284(1): 55-65, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28290782

RESUMO

Purpose To compare the prognostic importance (time to major adverse cardiovascular event [MACE]) of combined computed tomography (CT) angiography and CT myocardial stress perfusion imaging with that of combined invasive coronary angiography (ICA) and stress single photon emission CT myocardial perfusion imaging. Materials and Methods This study was approved by all institutional review boards, and written informed consent was obtained. Between November 2009 and July 2011, 381 participants clinically referred for ICA and aged 45-85 years were enrolled in the Combined Noninvasive Coronary Angiography and Myocardial Perfusion Imaging Using 320-Detector Row Computed Tomography (CORE320) prospective multicenter diagnostic study. All images were analyzed in blinded independent core laboratories, and a panel of physicians adjudicated all adverse events. MACE was defined as revascularization (>30 days after index ICA), myocardial infarction, or cardiac death; hospitalization for chest pain or congestive heart failure; or arrhythmia. Late MACE was defined similarly, except for patients who underwent revascularization within the first 182 days after ICA, who were excluded. Comparisons of 2-year survival (time to MACE) used standard Kaplan-Meier curves and restricted mean survival times bootstrapped with 2000 replicates. Results An MACE (49 revascularizations, five myocardial infarctions, one cardiac death, nine hospitalizations for chest pain or congestive heart failure, and one arrhythmia) occurred in 51 of 379 patients (13.5%). The 2-year MACE-free rates for combined CT angiography and CT perfusion findings were 94% negative for coronary artery disease (CAD) versus 82% positive for CAD and were similar to combined ICA and single photon emission CT findings (93% negative for CAD vs 77% positive for CAD, P < .001 for both). Event-free rates for CT angiography and CT perfusion versus ICA and single photon emission CT for either positive or negative results were not significantly different for MACE or late MACE (P > .05 for all). The area under the receiver operating characteristic curve (AUC) for combined CT angiography and CT perfusion (AUC = 68; 95% confidence interval [CI]: 62, 75) was similar (P = .36) to that for combined ICA and single photon emission CT (AUC = 71; 95% CI: 65, 79) in the identification of MACE at 2-year follow-up. Conclusion Combined CT angiography and CT perfusion enables similar prediction of 2-year MACE, late MACE, and event-free survival similar to that enabled by ICA and single photon emission CT. © RSNA, 2017 Online supplemental material is available for this article.


Assuntos
Angiografia por Tomografia Computadorizada , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/terapia , Imagem de Perfusão do Miocárdio , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Feminino , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Sensibilidade e Especificidade , Inquéritos e Questionários , Análise de Sobrevida
9.
Int J Cardiol ; 236: 100-106, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28262348

RESUMO

BACKGROUND: To evaluate the combined diagnostic accuracy of coronary computed tomography angiography (CCTA) and computed tomography derived fractional flow reserve (FFRct) in patients with suspected or known coronary artery disease (CAD). METHODS: PubMed, The Cochrane library, Embase and OpenGray were searched to identify studies comparing diagnostic accuracy of CCTA and FFRct. Diagnostic test measurements of FFRct were either extracted directly from the published papers or calculated from provided information. Bivariate models were conducted to synthesize the diagnostic performance of combined CCTA and FFRct at both "per-vessel" and "per-patient" levels. RESULTS: 7 articles were included for analysis. The combined diagnostic outcomes from "both positive" strategy, i.e. a subject was considered as "positive" only when both CCTA and FFRct were "positive", demonstrated relative high specificity (per-vessel: 0.91; per-patient: 0.81), high positive likelihood ratio (LR+, per-vessel: 7.93; per-patient: 4.26), high negative likelihood ratio (LR-, per-vessel: 0.30; per patient: 0.24) and high accuracy (per-vessel: 0.91; per-patient: 0.81) while "either positive" strategy, i.e. a subject was considered as "positive" when either CCTA or FFRct was "positive", demonstrated relative high sensitivity (per-vessel: 0.97; per-patient: 0.98), low LR+ (per-vessel: 1.50; per-patient: 1.17), low LR- (per-vessel: 0.07; per-patient: 0.09) and low accuracy (per-vessel: 0.57; per-patient: 0.54). CONCLUSION: "Both positive" strategy showed better diagnostic performance to rule in patients with non-significant stenosis compared to "either positive" strategy, as it efficiently reduces the proportion of testing false positive subjects.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Angiografia Coronária/métodos , Vasos Coronários/diagnóstico por imagem , Reserva Fracionada de Fluxo Miocárdico , Isquemia Miocárdica/diagnóstico , Precisão da Medição Dimensional , Humanos , Imagem Multimodal
10.
Singapore Med J ; 57(7): 401-5, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27193081

RESUMO

INTRODUCTION: Percutaneous transcatheter aortic valve implantation (TAVI) has become an established therapy for inoperable and high-surgical-risk patients with severe aortic stenosis. Although TAVI in patients with degenerated surgical aortic bioprostheses (i.e. valve-in-valve TAVI) is increasingly reported in Western studies, such data is lacking in Asian patients. We describe the initial experience of valve-in-valve TAVI in Asia. METHODS: Eight patients who underwent valve-in-valve TAVI due to degenerated aortic bioprostheses were enrolled. The mechanism of bioprosthetic valve failure was stenotic, regurgitation or mixed. All procedures were performed via transfemoral arterial access, using the self-expanding CoreValve prosthesis or balloon-expandable SAPIEN XT prosthesis. RESULTS: The mean age of the patients was 71.6 ± 13.2 years and five were male. Mean duration to surgical bioprosthesis degeneration was 10.2 ± 4.1 years. Valve-in-valve TAVI was successfully performed in all patients. CoreValve and SAPIEN XT prostheses were used in six and two patients, respectively. There were no deaths, strokes or permanent pacemaker requirement at 30 days, with one noncardiac mortality at one year. All patients experienced New York Heart Association functional class improvement. Post-procedure mean pressure gradients were 20 ± 11 mmHg and 22 ± 8 mmHg at 30 days and one year, respectively. Residual aortic regurgitation (AR) of more than mild severity occurred in one patient at 30 days. At one year, only one patient had mild residual AR. CONCLUSION: In our experience of valve-in-valve TAVI, procedural success was achieved in all patients without adverse events at 30 days. Good clinical and haemodynamic outcomes were sustained at one year.


Assuntos
Estenose da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Idoso , Idoso de 80 Anos ou mais , Insuficiência da Valva Aórtica/cirurgia , Artérias , Bioprótese , Cateterismo Cardíaco/métodos , Feminino , Fluoroscopia , Seguimentos , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Marca-Passo Artificial , Falha de Prótese , Índice de Gravidade de Doença
11.
PLoS One ; 11(5): e0153070, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27187726

RESUMO

Invasive fractional flow reserve (FFR) is the gold standard to assess the functional coronary stenosis. The non-invasive assessment of diameter stenosis (DS) using coronary computed tomography angiography (CTA) has high false positive rate in contrast to FFR. Combining CTA with computational fluid dynamics (CFD), recent studies have shown promising predictions of FFRCT for superior assessment of lesion severity over CTA alone. The CFD models tend to be computationally expensive, however, and require several hours for completing analysis. Here, we introduce simplified models to predict noninvasive FFR at substantially less computational time. In this retrospective pilot study, 21 patients received coronary CTA. Subsequently a total of 32 vessels underwent invasive FFR measurement. For each vessel, FFR based on steady-state and analytical models (FFRSS and FFRAM, respectively) were calculated non-invasively based on CTA and compared with FFR. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value were 90.6% (87.5%), 80.0% (80.0%), 95.5% (90.9%), 88.9% (80.0%) and 91.3% (90.9%) respectively for FFRSS (and FFRAM) on a per-vessel basis, and were 75.0%, 50.0%, 86.4%, 62.5% and 79.2% respectively for DS. The area under the receiver operating characteristic curve (AUC) was 0.963, 0.954 and 0.741 for FFRSS, FFRAM and DS respectively, on a per-patient level. The results suggest that the CTA-derived FFRSS performed well in contrast to invasive FFR and they had better diagnostic performance than DS from CTA in the identification of functionally significant lesions. In contrast to FFRCT, FFRSS requires much less computational time.


Assuntos
Reserva Fracionada de Fluxo Miocárdico , Modelos Teóricos , Tomografia Computadorizada por Raios X , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto
12.
Int J Cardiol ; 201: 570-7, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26334382

RESUMO

BACKGROUND: Myocardial CT perfusion (CTP) has been validated as an incremental diagnostic predictor over coronary computed tomography angiography (CTA) in assessing hemodynamically significant stenosis. OBJECTIVES: To assess the diagnostic performance of CTA and CTP alone versus combined CTA-CTP stratified by Morise's pre-test probability and coronary artery calcium (CAC, Agatston) score. METHODS: 381 individuals (153 low/intermediate-risk for CAD, 83 high-risk, 145 known CAD) were further stratified based on CAC score cut-offs of 1-399 and ≥400. Area under the curve for receiver operating characteristics (AUC) was calculated to assess the diagnostic performance. Reference standards were QCA≥50% stenosis+corresponding SPECT summed stress score ≥1. RESULTS: In both pre-test risk groups with an Agatston score of 1-399, AUCs of CTA-CTP were not significantly different than that from CTA alone. In the low/intermediate-risk group with CAC score 1-399, AUC for CTA-CTP (89) was higher than that for CTP (76, p=0.003) alone. In the same group with CAC score ≥400, AUCs were higher for CTA-CTP (97) than that for CTA (88, p=0.030) and CTP (83, p=0.033). In high risk/known CAD patients with CAC 1-399, diagnostic performance for CTA-CTP (77) was superior to CTP (71, p=0.037) alone. In the high risk/known CAD group with CAC score ≥400, AUCs for combined imaging were higher (86) than that for CTA (75, p<0.001) as well as CTP (78, p=0.020). CONCLUSIONS: The incremental diagnostic accuracy of CTP over CTA persists in patients across severity spectra of pre-test probability of CAD and coronary artery calcification. In patients with severe coronary calcification (CAC score≥400), combined CTA-CTP has better diagnostic accuracy than CTA and CTP alone.


Assuntos
Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico , Vasos Coronários , Tomografia Computadorizada Multidetectores/métodos , Imagem de Perfusão do Miocárdio/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Calcificação Vascular/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Vasos Coronários/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Curva ROC , Reprodutibilidade dos Testes , Índice de Gravidade de Doença
14.
Int J Numer Method Biomed Eng ; 31(4): e02708, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25630671

RESUMO

Local hemodynamic parameters, such as wall shear stress (WSS), oscillatory shear index and relative resident time (RRT), have been linked to coronary plaque initiation and progression. In this study, a left coronary artery tree model was reconstructed from computed tomography angiography images of a patient with multiple stenoses. The geometry of the coronary artery tree model was virtually restored by eliminating the lesions, essentially re-creating the virtually healthy artery anatomy. Using numerical simulations, flow characteristics and hemodynamic parameter distributions in the stenosed and virtually healthy models were investigated. In the virtually healthy artery model, disturbed flows were found at four locations, prone to initialization of plaque formation. Low WSS and high RRT were exhibited in three of the four locations, and high WSS and low RRT were exhibited in the fourth. These findings suggest that coronary plaque is more likely to form in locations with disturbed flow conditions characterized by low WSS and high RRT or high WSS and low RRT. In addition, clinical index of fractional flow reserve was found to significantly correlate with blood flow rate, rather than anatomic parameters, such as diameter stenosis, which implied the importance of hemodynamic environment in stenosis formation.


Assuntos
Vasos Coronários/fisiopatologia , Hemodinâmica/fisiologia , Angiografia/métodos , Velocidade do Fluxo Sanguíneo/fisiologia , Estenose Coronária/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Cardiovasculares , Placa Aterosclerótica/fisiopatologia , Estresse Mecânico
15.
BMC Cardiovasc Disord ; 14: 122, 2014 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-25245139

RESUMO

BACKGROUND: The optimal timing of pulmonary homograft valve replacement (PVR) is uncertain. Cardiopulmonary exercise testing (CPET) and cardiac magnetic resonance (CMR) are often used to guide the clinical decision for PVR in operated tetralogy of Fallot (TOF) patients with significant pulmonary regurgitation (PR). We aim to study the relationship between exercise capacity and CMR in these patients. METHODS: The study is a single-centre retrospective analysis of 36 operated TOF patients [median 21.4 (interquartile range 16.4, 26.4) years post-repair; 30 NYHA I, 6 NYHA II; median age 25.2 (interquartile range 19.5-31.7) years, 29 males] with significant PR on CMR who underwent CPET within 15 [median 2.0 (interquartile range 0.8-7.2)] months from CMR. CPET parameters were compared with 30 age- and sex-matched healthy controls [median age 27.8 (interquartile range 21.0-32.8) years; 24 males]. RESULTS: Peak systolic blood pressure (177 versus 192 mmHg, p = 0.007), Mets (7.3 versus 9.9, p < 0.001), peak oxygen consumption (VO2max) (29.2 versus 34.5 ml/kg/min, p < 0.001) and peak oxygen pulse (11.0 versus 13.7 ml/beat, p = 0.003) were significantly lower in TOF group versus control. Univariate analyses showed negative correlation between PR fraction and anaerobic threshold. There was a positive correlation between indexed left (LV) and right (RV) ventricular end-diastolic volumes, as well as indexed LV and effective RV stroke volumes, on CMR and VO2max and Mets achieved on CPET. These remained significant after adjustment for age and sex. CONCLUSIONS: TOF subjects have near normal exercise capacity but significantly lower Mets, VO2max and peak oygen pulse achieved compared to controls. Increased PR fraction in TOF subjects was associated with lower anaerobic threshold. Higher indexed effective RV stroke volume, a measure of LV preload, was associated with higher VO2max and Mets achieved, and may potentially be used as a predictor of exercise capacity.


Assuntos
Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Tolerância ao Exercício , Imagem Cinética por Ressonância Magnética , Insuficiência da Valva Pulmonar/diagnóstico , Tetralogia de Fallot/cirurgia , Função Ventricular Esquerda , Adolescente , Adulto , Teste de Esforço , Feminino , Humanos , Masculino , Consumo de Oxigênio , Valor Preditivo dos Testes , Insuficiência da Valva Pulmonar/etiologia , Insuficiência da Valva Pulmonar/fisiopatologia , Estudos Retrospectivos , Singapura , Tetralogia de Fallot/diagnóstico , Tetralogia de Fallot/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Função Ventricular Direita , Adulto Jovem
16.
Biomed Res Int ; 2014: 514729, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24987691

RESUMO

Fractional flow reserve (FFR) is the gold standard to guide coronary interventions. However it can only be obtained via invasive angiography. The objective of this study is to propose a noninvasive method to determine FFRCT by combining computed tomography angiographic (CTA) images and computational fluid dynamics (CFD) technique. Utilizing the method, this study explored the effects of diameter stenosis (DS), stenosis length, and location on FFRCT. The baseline left anterior descending (LAD) model was reconstructed from CTA of a healthy porcine heart. A series of models were created by adding an idealized stenosis (with DS from 45% to 75%, stenosis length from 4 mm to 16 mm, and at 4 locations separately). Through numerical simulations, it was found that FFRCT decreased (from 0.89 to 0.74), when DS increased (from 45% to 75%). Similarly, FFRCT decreased with the increase of stenosis length and the stenosis located at proximal position had lower FFRCT than that at distal position. These findings are consistent with clinical observations. Applying the same method on two patients' CTA images yielded FFRCT close to the FFR values obtained via invasive angiography. The proposed noninvasive computation of FFRCT is promising for clinical diagnosis of CAD.


Assuntos
Circulação Coronária , Estenose Coronária/fisiopatologia , Vasos Coronários/fisiopatologia , Modelos Cardiovasculares , Miocárdio , Animais , Velocidade do Fluxo Sanguíneo , Estenose Coronária/patologia , Vasos Coronários/patologia , Humanos , Suínos
17.
Eur Heart J ; 35(17): 1120-30, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24255127

RESUMO

AIMS: To evaluate the diagnostic power of integrating the results of computed tomography angiography (CTA) and CT myocardial perfusion (CTP) to identify coronary artery disease (CAD) defined as a flow limiting coronary artery stenosis causing a perfusion defect by single photon emission computed tomography (SPECT). METHODS AND RESULTS: We conducted a multicentre study to evaluate the accuracy of integrated CTA-CTP for the identification of patients with flow-limiting CAD defined by ≥50% stenosis by invasive coronary angiography (ICA) with a corresponding perfusion deficit on stress single photon emission computed tomography (SPECT/MPI). Sixteen centres enroled 381 patients who underwent combined CTA-CTP and SPECT/MPI prior to conventional coronary angiography. All four image modalities were analysed in blinded independent core laboratories. The prevalence of obstructive CAD defined by combined ICA-SPECT/MPI and ICA alone was 38 and 59%, respectively. The patient-based diagnostic accuracy defined by the area under the receiver operating characteristic curve (AUC) of integrated CTA-CTP for detecting or excluding flow-limiting CAD was 0.87 [95% confidence interval (CI): 0.84-0.91]. In patients without prior myocardial infarction, the AUC was 0.90 (95% CI: 0.87-0.94) and in patients without prior CAD the AUC for combined CTA-CTP was 0.93 (95% CI: 0.89-0.97). For the combination of a CTA stenosis ≥50% stenosis and a CTP perfusion deficit, the sensitivity, specificity, positive predictive, and negative predicative values (95% CI) were 80% (72-86), 74% (68-80), 65% (58-72), and 86% (80-90), respectively. For flow-limiting disease defined by ICA-SPECT/MPI, the accuracy of CTA was significantly increased by the addition of CTP at both the patient and vessel levels. CONCLUSIONS: The combination of CTA and perfusion correctly identifies patients with flow limiting CAD defined as ≥50 stenosis by ICA causing a perfusion defect by SPECT/MPI.


Assuntos
Estenose Coronária/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Idoso , Estenose Coronária/fisiopatologia , Feminino , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores , Imagem de Perfusão do Miocárdio/métodos , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade
18.
Conf Proc IEEE Eng Med Biol Soc ; 2013: 3865-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24110575

RESUMO

Fractional flow reserve (FFR) determined by invasive angiography is the gold standard to assess the severity of coronary artery disease (CAD). FFRCT can be obtained non-invasively by combining computed tomography (CT) images and Computational Fluid Dynamics (CFD) method. In this study, FFRCT was computed for 6 models of patient-specific left coronary artery trees reconstructed from CT images. A total of 12 stenoses were observed. FFR values obtained for 7 of the 12 stenoses during invasive angiography were used as the gold standard for comparison. On a per-stenosis basis, the sensitivity, specificity, positive predictive value and negative predictive value were 50%, 100%, 100% and 83.3% respectively for FFRCT. A weak correlation was found between percent lumen diameter stenosis and FFRCT (r=0.431; p>0.05). However, the correlation between percent lumen area stenosis and FFRCT was significant (r=0.853; p<0.05). Therefore, non-invasive FFRCT appears to be a promising index to assess the severity of CAD and lumen area has distinct advantages over diameter measurement in terms of anatomy assessment.


Assuntos
Dor no Peito/diagnóstico , Estenose Coronária/diagnóstico , Vasos Coronários/diagnóstico por imagem , Meios de Contraste , Estenose Coronária/diagnóstico por imagem , Estenose Coronária/patologia , Reserva Fracionada de Fluxo Miocárdico , Hemodinâmica , Humanos , Pessoa de Meia-Idade , Modelos Cardiovasculares , Estudos Prospectivos , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X
19.
Ann Thorac Surg ; 96(2): e43-5, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23910144

RESUMO

Anomalous coronary arteries are rare but can lead to serious complications during cardiac operations if not recognized. We report a 55-year-old woman with anomalous origin of the right coronary artery from the left ventricle, and bicuspid aortic valve stenosis. Coronary angiography and computerized tomographic angiography indicated the diagnosis preoperatively. She underwent aortic valve replacement and coronary artery bypass grafting subsequently, with good recovery. One adult and two children with the same right coronary artery anomaly have been reported in the literature. Preoperative diagnosis is essential in these cases, and long-term follow-up is warranted.


Assuntos
Anormalidades Múltiplas , Estenose da Valva Aórtica/complicações , Valva Aórtica/anormalidades , Anomalias dos Vasos Coronários/complicações , Cardiopatias Congênitas/complicações , Anormalidades Múltiplas/cirurgia , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Anomalias dos Vasos Coronários/cirurgia , Feminino , Cardiopatias Congênitas/cirurgia , Humanos , Pessoa de Meia-Idade
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