Preprocedural Computed Tomography Planning for Surgical Aortic Valve Replacement.

BACKGROUND: Selection of transcatheter valve size using preprocedural computed tomography (CT) is standardized and well established. However, valve sizing for surgical aortic valve replacement (SAVR) is currently performed intraoperatively by using sizers, which may result in variation among operators and risk for prosthesis-patient mismatch. This study evaluated the usefulness of CT annulus measurement for SAVR valve sizing. METHODS: This study included patients who underwent SAVR using Inspiris or Magna Ease and received preoperative electrocardiogram-gated CT imaging. Starting from June 2022, study investigators applied a CT sizing algorithm using CT-derived annulus size to guide minimum SAVR label size. The final decision of valve selection was left to the operating surgeon during SAVR. The study compared the appropriateness of valve selection (comparing implanted size with CT-predicted size) and prosthesis-patient mismatch rates without aortic root enlargement between 2 cohorts: 102 cases since June 2022 (CT sizing cohort) and 180 cases from 2020 to 2021 (conventional sizing cohort). RESULTS: Implanted size smaller than CT predicted size and severe prosthesis-patient mismatch were significantly lower by CT sizing than by conventional sizing (12% vs 31% [P = .001] and 0% vs 6% [P = .039], respectively). Interoperator variability was a factor associated with implanted size smaller than CT predicted with conventional sizing, whereas it became nonsignificant with CT sizing. CONCLUSIONS: Applying CT sizing to SAVR led to improved valve size selection, less prosthesis-patient mismatch, and less interoperator variability. CT sizing for SAVR could also be used to predict prosthesis-patient mismatch before SAVR and identify patients who need aortic root enlargement.

Comprehensive Myocardial Assessment by Computed Tomography: Impact on Short-Term Outcomes After Transcatheter Aortic Valve Replacement.

BACKGROUND: Quantification of myocardial changes in severe aortic stenosis (AS) is prognostically important. The potential for comprehensive myocardial assessment pre-transcatheter aortic valve replacement (TAVR) by computed tomography angiography (CTA) is unknown. OBJECTIVES: This study sought to evaluate whether quantification of left ventricular (LV) extracellular volume-a marker of myocardial fibrosis-and global longitudinal strain-a marker of myocardial deformation-at baseline CTA associate with post-TAVR outcomes. METHODS: Consecutive patients with symptomatic severe AS between January 2021 and June 2022 who underwent pre-TAVR CTA were included. Computed tomography extracellular volume (CT-ECV) was derived from septum tracing after generating the 3-dimensional CT-ECV map. Computed tomography global longitudinal strain (CT-GLS) used semi-automated feature tracking analysis. The clinical endpoint was the composite outcome of all-cause mortality and heart failure hospitalization. RESULTS: Among the 300 patients (80.0 ± 9.4 years of age, 45% female, median Society of Thoracic Surgeons Predicted Risk of Mortality score 2.80%), the left ventricular ejection fraction (LVEF) was 58% ± 12%, the median CT-ECV was 28.5% (IQR: 26.2%-32.1%), and the median CT-GLS was -20.1% (IQR: -23.8% to -16.3%). Over a median follow-up of 16 months (IQR: 12-22 months), 38 deaths and 70 composite outcomes occurred. Multivariable Cox proportional hazards model, accounting for clinical and echocardiographic variables, demonstrated that CT-ECV (HR: 1.09 [95% CI: 1.02-1.16]; P = 0.008) and CT-GLS (HR: 1.07 [95% CI: 1.01-1.13]; P = 0.017) associated with the composite outcome. In combination, elevated CT-ECV and CT-GLS (above median for each) showed a stronger association with the outcome (HR: 7.14 [95% CI: 2.63-19.36]; P < 0.001). CONCLUSIONS: Comprehensive myocardial quantification of CT-ECV and CT-GLS associated with post-TAVR outcomes in a contemporary low-risk cohort with mostly preserved LVEF. Whether these imaging biomarkers can be potentially used for the decision making including timing of AS intervention and post-TAVR follow-up will require integration into future clinical trials.

Feasibility of Redo-Transcatheter Aortic Valve Replacement in Sapien Valves Based on In Vivo Computed Tomography Assessment.

BACKGROUND: Our aim was to assess the feasibility of repeat transcatheter aortic valve (TAV) replacement for degenerated Sapien3 (S3) prostheses by simulating subsequent implantation of S3 or Evolut, using in vivo computed tomography-based sizing and the impact on coronary and patient-prosthesis mismatch risks. METHODS: Computed tomography scans from 356 patients with prior S3 TAV replacement implantation were analyzed. The in vivo sizing for second TAV based on averaged area of 3 levels of outflow, mid (narrowest) and inflow, was compared with in vitro recommendations, that is, same size as index S3 for second S3 and 1 size larger for Evolut. Risks of coronary obstruction and patient-prosthesis mismatch were determined by valve-to-aorta distance and estimated effective orifice area, respectively. RESULTS: Overall, the majority of patients (n=328; 92.1%) had underexpanded index S3 with an expansion area of 94% (91%-97%), leading to significant differences in size selection of the second TAV between in vivo and in vitro sizing strategies. Expansion area <89% served as a threshold, resulting in 1 size smaller than the in vitro recommendations were selected in 45 patients (13%) for S3-in-S3 and 13 (4%) for Evolut-in-S3, while the remaining patients followed in vitro recommendations (P<0.01, in vivo versus in vitro sizing). Overall, 57% of total patients for S3-in-S3 simulation and 60% for Evolut-in-S3 were considered low risk for coronary complications. Deep index S3 implantation (odds ratio, 0.76 [interquartile range, 0.67-0.87]; P<0.001) and selecting Evolut as the second TAV (11% risk reduction in intermediate- or high-risk patients) reduced coronary risk. Estimated moderate or severe patient-prosthesis mismatch risk was 21% for S3-in-S3 and 1% for Evolut-in-S3, assuming optimal expansion of the second TAV. CONCLUSIONS: Redo-TAV replacement with S3-in-S3 and Evolut-in-S3 could be feasible with low risk to coronaries in ≈60% of patients, while the remaining 40% will be at intermediate or high risk. The feasibility of redo-TAV replacement is influenced by sizing strategy, type of second TAV, native annular anatomy, and implant depth.

Deformation of transcatheter heart valves with mitral valve-in-valve.

BACKGROUND: The use of oversizing in mitral valve-in-valve (MViV) procedures can lead to non-uniform expansion of transcatheter heart valves (THV). This may have implications for THV durability. AIMS: The objective of this study was to assess the extent and predictors of THV deformation in MViV procedures. METHODS: We examined 33 patients who underwent MViV with SAPIEN prostheses. The extent of THV deformation (deformation index, eccentricity, neosinus volume, asymmetric leaflet expansion and vertical deformation) and hypoattenuating leaflet thickening (HALT) were assessed using cardiac computed tomography (CT), performed prospectively at 30 days post-procedure. For descriptive purposes, the THV deformation index was calculated, with values >1.00 representing a more hourglass shape. RESULTS: Non-uniform underexpansion of THV was common after MViV implantation, with a median expansion area of 74.0% (interquartile range 68.1-84.1) at the narrowest level and a THV deformation index of 1.21 (1.13-1.29), but circularity was maintained with eccentricity ranging from 0.24 to 0.28. The degree of oversizing was a key factor associated with greater underexpansion and a higher deformation index (ß=-0.634; p<0.001; ß=0.594; p<0.001, respectively). Overall, the incidence of HALT on the 30-day postprocedural CT was 27.3% (9 of 33). Most patients (32 of 33) were on anticoagulation therapy, but the prothrombin time and international normalised ratio (PT-INR) at the time of the CT scan was <2.5 in 23 of 32 patients. Among patients with a PT-INR of <2.5, HALT was predominantly observed with a high THV deformation index of ≥1.18. CONCLUSIONS: THV deformation, i.e., underexpansion and an hourglass shape, commonly occurs after MViV implantation and is negatively affected by excessive oversizing. Optimising THV expansion during MViV could potentially prevent HALT.

Importance of imaging-acquisition protocol and post-processing analysis for extracellular volume fraction assessment by computed tomography.

BACKGROUND: Computed tomography angiography (CTA) assessment of myocardial extracellular volume fraction (CT-ECV) is feasible, although the protocols for imaging acquisition and post-processing methodology have varied. We aimed to identify a pragmatic protocol for CT-ECV assessment encompassing both imaging acquisition and post-processing methodologies to facilitate its clinical implementation. METHODS: We evaluated consecutive patients with severe aortic stenosis undergoing evaluation for transcatheter aortic valve replacement (TAVR). Pre-contrast and 3-min-delayed CTA were obtained in systole using either helical prospective-ECG-triggered (high-pitch) or axial sequential-ECG-gated acquisition, adding to standard TAVR CTA protocol. Using a dedicated software for co-registration of CTA datasets, three methodologies for ECV measurement were evaluated: (1) mid-septum region of interest (Septal ECV), (2) averaged-global ECV (Global ECV) encompassing 16-AHA segments, and (3) average of septal and lateral segments (Averaged ECVsep and Averaged ECVlat). RESULTS: Among the 142 patients enrolled (median â€‹= â€‹81 years, 44% females), 8 were excluded due to significant imaging artifacts precluding Global ECV assessment. High-pitch scan mode was performed in 68 patients (48%). Suboptimal image quality for Global ECV assessment was associated with high-pitch scan mode (odds ratio: OR â€‹= â€‹2.26, p â€‹= â€‹0.036), along with the presence of intracardiac leads (OR â€‹= â€‹4.91, p â€‹= â€‹0.002), and BMI≥35 â€‹kg/m2 (OR â€‹= â€‹2.80, p â€‹= â€‹0.026). Septal ECV [median â€‹= â€‹29.4%] and Averaged ECVsep [29.0%] were similar (p â€‹= â€‹0.108), while Averaged ECVlat [27.5%] was lower than Averaged ECVsep (p â€‹< â€‹0.001), resulting in lower Global ECV [28.6%]. CONCLUSIONS: Myocardial CT-ECV assessment is feasible using a systolic sequential acquisition pre-contrast, and similar additional 3-min delayed scan. Septal ECV measurement provides similar values to Global ECV and is equally reproducible.

Deformation of Transcatheter Heart Valve Following Valve-in-Valve Transcatheter Aortic Valve Replacement: Implications for Hemodynamics.

BACKGROUND: Valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) may be associated with adverse hemodynamics, which might affect clinical outcomes. OBJECTIVES: This study sought to evaluate the extent and predictors of transcatheter heart valve (THV) deformity in ViV TAVR and the relation to postprocedural hemodynamics. METHODS: We examined 53 patients who underwent ViV TAVR in surgical heart valves with self-expanding Evolut prostheses. THV deformation was examined using cardiac computed tomography prospectively performed 30 days after ViV TAVR, and correlated with 30-day echocardiographic hemodynamic data. RESULTS: Near complete expansion of the functional portion of the implanted ViV prostheses (ie, >90%) was observed in 16 (30.2%) patients. Factors related to greater expansion of the functional portion and consequently larger neosinus volume were absence of polymer surgical frame, higher implantation and use of balloon aortic valvuloplasty or bioprosthetic valve fracture during the procedure (all P < 0.05). Underexpansion of the functional portion, but not the valve inflow frame, was closely associated with mean gradient and effective orifice area at 30 days on echocardiography, with and without adjustment for the sizes of the THV and surgical heart valve. CONCLUSIONS: Underexpansion of the functional portion of THV prostheses is common during ViV TAVR, occurs more frequently with deep implantation and the presence of a polymer surgical stent frame, and is associated with worse postprocedural hemodynamics. Procedural techniques, such as higher implantation and balloon postdilatation, may be used to help overcome problems with THV underexpansion and improve clinical outcomes.

Deformation of Transcatheter Aortic Valve Prostheses: Implications for Hypoattenuating Leaflet Thickening and Clinical Outcomes.

BACKGROUND: Although transcatheter aortic valve replacement (TAVR) therapy continues to grow, there have been concerns about the occurrence of hypoattenuating leaflet thickening (HALT), which may affect prosthesis function or durability. This study aimed to examine prosthesis frame factors and correlate their extent to the frequency of HALT and clinical outcomes. METHODS: We prospectively examined 565 patients with cardiac computed tomography screening for HALT at 30 days after balloon-expandable SAPIEN3 and self-expanding EVOLUT TAVR. Deformation of the TAVR prostheses, asymmetric prosthesis leaflet expansion, prosthesis sinus volumes, and commissural alignment were analyzed on the postprocedural computed tomography. For descriptive purposes, an index of prosthesis deformation was calculated, with values >1.00 representing relative midsegment underexpansion. A time-to-event model was performed to evaluate the association of HALT with the clinical outcome. RESULTS: Overall, HALT was present in 21% of SAPIEN3 patients and in 16% of EVOLUT patients at 30 days after TAVR. The occurrence of HALT was directly associated with greater prosthesis frame deformation (P<0.001), worse asymmetry of the leaflets (P<0.001), and smaller TAVR neosinus volumes (P<0.001). These relations were present in both prosthetic types and in all of their size ranges (all P<0.05). In multivariable analyses that include clinical variables previously associated with HALT (eg, anticoagulant therapy), variables of TAVR prosthesis deformation remained predictive of HALT. Although HALT was not associated with changes in prosthetic hemodynamics, its presence was associated with the risk of mortality at 1 year, with respect to greater incidences of all-cause mortality (hazard ratio, 2.98 [95% CI, 1.57-5.63]; P=0.001), cardiac death (hazard ratio, 4.58 [95% CI, 1.81-11.6]; P=0.001), and a composite outcome of all-cause mortality and heart failure hospitalization (hazard ratio, 1.94 [95% CI, 1.14-3.30]; P=0.02) with adjustment for age, sex, and comorbidities. CONCLUSIONS: Nonuniform expansion of TAVR prostheses resulting in frame deformation, asymmetric leaflet, and smaller neosinus volume is related to occurrence of HALT in patients who undergo TAVR. These data may have implications for both prosthesis valve design and deployment techniques to improve clinical outcomes for these patients.

Association of baseline and change in global longitudinal strain by computed tomography with post-transcatheter aortic valve replacement outcomes.

AIMS: Transcatheter aortic valve replacement (TAVR) procedural planning requires computed tomography angiography (CTA) which allows for the assessment of left ventricular global longitudinal strain (CTA-LVGLS). There is, however, limited data on the feasibility of CTA-LVGLS, and its prognostic value. This study sought to evaluate the incremental prognostic value of baseline CTA-LVGLS, change in CTA-LVGLS after TAVR, and their association with post-TAVR outcomes. METHODS AND RESULTS: A total of 431 patients who underwent multiphasic gated CTA using dual-source system for TAVR planning at baseline and 1-month follow-up were included [median (interquartile range) age, 83 (77-87) years; 44% female, STS-PROM score: 3.3 (2.3-5.1)%, Echo-left ventricular ejection fraction (LVEF): 60 (55-65)%, CTA-LVGLS: -18.0 (-21.6 to -14.2)%, feasible in 97% of patients]. CTA-LVGLS was measured using dedicated feature-tracking software. Over a median follow-up of 19 (13-27) months, 99 endpoints of all-cause death or heart failure hospitalization occurred. The relative hazard of the endpoint increased as baseline CTA-LVGLS worsened with -18.2% as the threshold for higher events (P = 0.005). After adjustment for baseline characteristics, CTA-LVGLS remained associated with the endpoint [hazard ratio (HR) (95% confidence interval, CI), 1.08 (1.03-1.14); P = 0.005] and incrementally improved prognostication (C-index difference, 0.026). Although CTA-LVGLS improved after TAVR [-18.3 (-21.6 to -14.3)% vs. -18.7 (-21.9 to -15.4)%, P < 0.001], patients without CTA-LVGLS improvement had higher risk of the endpoint than those with improvement or preserved baseline global longitudinal strain [HR (95% CI), 1.92 (1.19-3.12); P = 0.008]. CONCLUSIONS: In this predominantly low-risk TAVR cohort of patients, mostly with normal LVEF, assessment of CTA-LVGLS is highly feasible improving risk stratification by providing independent and incremental prognostic value over clinical and echocardiographic characteristics.

Right ventricular dysfunction by computed tomography associates with outcomes in severe aortic stenosis patients undergoing transcatheter aortic valve replacement.

BACKGROUND: Although cardiac computed tomography angiography (CCTA) assessment of right ventricular dysfunction (RVD) is feasible, the incremental prognostic value remains uncertain in patients undergoing transcatheter aortic valve replacement (TAVR) evaluation. This study sought to determine the incremental clinical utility of RVD identification by CCTA while accounting for clinical and echocardiographic parameters. METHODS: Patients who underwent multiphasic ECG-gated functional CCTA using dual-source system for routine TAVR planning were evaluated. Biphasic contrast protocol injection allowed for biventricular contrast enhancement. CCTA-based RVD was defined as right ventricular ejection fraction (RVEF) â€‹< â€‹50%. The association of CCTA-RVD with all-cause mortality and the composite outcome of death or heart failure hospitalization after TAVR was evaluated and examined for its incremental utility beyond clinical risk assessment and echocardiographic parameters. RESULTS: A total of 502 patients were included (median [IQR] age, 82 [77 to 87] years; 56% men) with a median follow-up of 22 [16 to 32] months. Importantly, 126 (25%) patients were identified as having RVD by CCTA that was not identified by echocardiography. CCTA-defined RVD predicted death and the composite outcome in both univariate analyses (HR for mortality, 2.15; 95% CI, 1.44-3.22; p â€‹< â€‹0.001; HR for composite outcome, 2.11; 95% CI, 1.48-3.01; p â€‹< â€‹0.001) and in multivariate models that included clinical risk factors and echocardiographic findings (HR for mortality, 1.74; 95% CI, 1.11-2.74; p â€‹= â€‹0.02; HR for composite outcome, 1.63; 95% CI, 1.09-2.44; p â€‹= â€‹0.02). CONCLUSIONS: Functional CCTA assessment pre-TAVR correctly identified 25% of patients with RVD that was not evident on 2D echocardiography. The presence of RVD on CCTA independently associates with clinical outcomes post-TAVR.

Relation of Guideline Adherence to Outcomes in Patients With Asymptomatic Severe Primary Mitral Regurgitation.

Current guidelines empirically recommend serial clinical evaluations for asymptomatic patients with severe mitral regurgitation (MR). However, there is a paucity of data on the effectiveness of such monitoring. This study sought to examine the potential benefit of guideline adherence among asymptomatic patients with severe primary MR. Asymptomatic patients with severe primary MR who had been evaluated in the Allina Health system between January 1, 2012 and May 30, 2018 were examined. The medical records were manually reviewed for demographics, comorbidities, echocardiographic data, subsequent interventions, and clinical outcomes. Patients were grouped according to occurrence of guideline adherence, which was defined as a serial clinical evaluation with echocardiography every 12 ± 1 month until mitral valve surgery, or death. Over the study period, 246 patients (67.3 ± 15.5 years, 61.4% men) with severe, asymptomatic primary MR were identified, including 154 patients (62.6%) with and 92 patients (37.4%) without guideline adherence. Overall, there were no differences in demographics, morbidities, MR severity, or left ventricular function between patient adherence groups. During follow-up (40.9; 21.2, 58.3 months), patients with adherence more frequently had surgery or transcatheter therapy performed (64.3% vs 18.5%; p <0.001) and the time to intervention was earlier (13.6 [3.9-22.7] vs 44.2[25.6-57.3] months; p <0.001). Compared to non-adherent patients, those with guideline adherence had a significantly higher five-year survival free from all-cause mortality (92.0% vs 74.3%, p = 0.002), and freedom from death or hospitalization for heart failure (90.1% vs 69.3%, p = 0.001). Adherent patients also had a significantly better survival free from combined endpoint of death, re-hospitalization for heart failure, myocardial infarction, and stroke (84.5% vs 63.2%, p = 0.002). In patients with asymptomatic severe primary MR, guideline adherence with serial evaluations every 12 months or less is associated with earlier therapy and improved long-term outcomes. These data support educational efforts to promote guideline adherence.

Multi-institution assessment of the use and risk of cardiovascular computed tomography in pediatric patients with congenital heart disease.

BACKGROUND: Cardiac computed tomography (CT) is increasingly used in pediatric patients with congenital heart disease (CHD). Variability of practice and of comprehensive diagnostic risk across institutions is not known. METHODS: Four centers prospectively enrolled consecutive pediatric CHD patients <18 years of age undergoing cardiac CT from January 6, 2017 to 1/30/2020. Patient characteristics, cardiac CT data and comprehensive diagnostic risk were compared by age and institutions. Risk categories included sedation and anesthesia use, vascular access, contrast exposure, cardiovascular medication, adverse events (AEs), and estimated radiation dose. RESULTS: Cardiac CT was performed in 1045 pediatric patients at a median (interquartile range, IQR) age of 1.7 years (0.3, 11.0). The most common indications were arterial abnormalities, suspected coronary artery anomalies, functionally single ventricle heart disease, and tetralogy of Fallot/pulmonary atresia. Sedation was used in 8% and anesthesia in 11% of patients. Peripheral vascular access was utilized for 93%. Median contrast volume was 2 â€‹ml/kg. Beta blockers were administered in 11% of cases and nitroglycerin in 2% of cases. The median (IQR) total procedural dose length product (DLP) was 20 â€‹mGy∗cm (10, 50). Sedation, vascular access, contrast exposure, use of cardiovascular medications and radiation dose estimates varied significantly by institution and age (p â€‹< â€‹0.001). Seven minor adverse events (0.7%) and no major adverse events were reported. CONCLUSION: Cardiac CT for CHD is safe in pediatric patients when appropriate CT technology and expertise are available. Scans can be acquired at relatively low radiation exposure with few minor adverse events.

Prosthesis-patient mismatch defined by cardiac computed tomography versus echocardiography after transcatheter aortic valve replacement.

BACKGROUNDS: Evaluation of prosthesis-patient mismatch (P-PM) after transcatheter aortic valve replacement (TAVR) by transthoracic echocardiography (TTE) has provided conflicting results regarding its impact on outcomes. Whether post-TAVR computed tomography angiography (CTA) evaluation of P-PM can improve our understanding is unknown. We aimed to evaluate the inter-modality (TTE vs. CTA) agreement, inter-valve platform (balloon-expanding valve [BEV] vs. self-expandable valve [SEV]) differences in P-PM severity, and outcomes related to P-PM after TAVR. METHODS: We analyzed patients with both CTA and TTE before and after TAVR. Indexed effective orifice area was calculated using two methods: TTE-derived left ventricular outflow tract (LVOT) area from measured diameter and post-TAVR CTA-measured area. Body size specific cut-offs for P-PM severity were used: for body mass index (BMI) â€‹< â€‹30 â€‹kg/m2, moderate â€‹= â€‹0.66-0.85 â€‹cm2/m2 and severe≤0.65 â€‹cm2/m2; for BMI ≥30 â€‹kg/m2, moderate â€‹= â€‹0.56-0.70 â€‹cm2/m2 and severe≤0.55 â€‹cm2/m2. RESULTS: A total of 447 patients were included (median age, 83 years; 54% male). The prevalence of P-PM (moderate or severe) was lower with CTA vs. TTE (3.5% vs. 19.5%, p â€‹< â€‹0.001). The prevalence of P-PM measured by TTE was more common in BEV compared to SEV (p â€‹= â€‹0.002), while CTA assessment showed no difference in P-PM incidence and severity between TAVR platforms (p â€‹= â€‹0.40). In multivariable analysis, CTA-defined but not TTE-defined P-PM was associated with mortality after TAVR (HR:3.97; 95%CI,1.55-10.2; p â€‹= â€‹0.004). Both CTA-defined and TTE-defined P-PM were associated with the composite of death and heart failure rehospitalization. CONCLUSION: Although post-TAVR CTA substantially downgraded the prevalence of P-PM compared to TTE, it identified a subset of patients with clinically relevant P-PM which associated with outcomes.

Safety, Efficacy, and Dose Protocol of Metoprolol for Heart Rate Reduction in Pediatric Outpatients Undergoing Cardiac CT Angiography. / Segurança, Eficácia e Protocolo de Dose de Metoprolol para Redução de Frequência Cardíaca em Pacientes Pediátricos Externos que Passaram por Angiografia Cardíaca por TC.

BACKGROUND: Image quality and radiation dose are optimized with a slow, steady heart rate (HR) when imaging the coronary arteries during cardiac computed tomography angiography (CCTA). The safety, efficacy, and protocol for HR reduction with beta blocker medication is not well described in a pediatric patient population. OBJECTIVE: Provide a safe and efficient metoprolol dose protocol to be used in pediatric outpatients undergoing CCTA. METHODS: We conducted a retrospective review of all pediatric outpatients who received metoprolol during CCTA. Demographic and clinical characteristics were summarized and the average reduction in HR was estimated using a multivariate linear regression model. Images were evaluated on a 1-4 scale (1= optimal). RESULTS: Seventy-eight pediatric outpatients underwent a CCTA scan with the use of metoprolol. The median age was 13 years, median weight of 46 kg, and 36 (46%) were male. The median doses of metoprolol were 1.5 (IQR 1.1, 1.8) mg/kg and 0.4 (IQR 0.2, 0.7) mg/kg for oral and intravenous administrations, respectively. Procedural dose-length product was 57 (IQR 30, 119) mGy*cm. The average reduction in HR was 19 (IQR 12, 26) beats per minute, or 23%. No complications or adverse events were reported. CONCLUSION: Use of metoprolol in a pediatric outpatient setting for HR reduction prior to CCTA is safe and effective. A metoprolol dose protocol can be reproduced when a slower HR is needed, ensuring faster acquisition times, clear images, and associated reduction in radiation exposure in this population. (Arq Bras Cardiol. 2021; 116(1):100-105).

FUNDAMENTO: Qualidade de imagem e dose de radiação são otimizadas com uma frequência cardíaca (FC) lenta e estável na realização de imagens de artérias coronárias durante a angiografia cardíaca por tomografia computadorizada (CCTA, do inglês cardiac computed tomography angiography) A segurança, a eficácia e o protocolo para a redução da FC com medicamento betabloqueador ainda não foi bem descrita em uma população de pacientes pediátricos. OBJETIVO: Oferecer um protocolo de dose de metoprolol eficiente a ser usado em pacientes pediátricos externos durante a CCTA. MÉTODOS: Realizamos uma revisão retrospectiva de todos os pacientes pediátricos externos que receberam o metoprolol durante a CCTA. As características demográficas e clínicas foram resumidas e a redução média em FC foi estimada utilizando-se um modelo de regressão linear multivariada. As imagens foram avaliadas em uma escala de 1 a 4 (1= ideal). RESULTADOS: Um total de 78 pacientes externos passaram a uma CCTA com o uso de metoprolol. A média de idade foi de 13 anos, a média de peso foi de 46 kg, e 36 pacientes (46%) eram do sexo masculino. As doses médias de metoprolol foram 1,5 (IQR 1,1; 1,8) mg/kg, e 0,4 (IQR 0,2; 0,7) mg/kg para administrações orais e intravenosas, respectivamente. O produto dose-comprimento por exame foi de 57 (IQR 30, 119) mGy*cm. A redução média da FC foi 19 (IQR 12, 26) batimentos por minuto, ou 23%. Não foram relatadas complicações ou eventos adversos. CONCLUSÃO: O uso de metoprolol num cenário de pacientes pediátricos externos para redução da FC antes de uma CCTA é seguro e eficiente. Pode-se reproduzir um protocolo de dose de metoprolol quando for necessário atingir uma FC mais lenta, garantindo tempos de aquisição mais rápidos, imagens mais claras e redução na exposição à radiação nessa população. (Arq Bras Cardiol. 2021; 116(1):100-105).

Importance of Myocardial Fibrosis in Functional Mitral Regurgitation: From Outcomes to Decision-Making.

Functional mitral regurgitation (FMR) is a common and complex valve disease, in which severity and risk stratification is still a conundrum. Although risk increases with FMR severity, it is modulated by subjacent left ventricular (LV) disease. The extent of LV remodeling and dysfunction is traditionally evaluated by echocardiography, but a growing body of evidence shows that myocardial fibrosis (MF) assessment by cardiac magnetic resonance (CMR) may complement risk stratification and inform treatment decisions. This review summarizes the current knowledge on the comprehensive evaluation that CMR can provide for patients with FMR, in particular for the assessment of MF and its potential impact in clinical decision-making.

Segurança, Eficácia e Protocolo de Dose de Metoprolol para Redução de Frequência Cardíaca em Pacientes Pediátricos Externos que Passaram por Angiografia Cardíaca por TC / Safety, Efficacy, and Dose Protocol of Metoprolol for Heart Rate Reduction in Pediatric Outpatients Undergoing Cardiac CT Angiography

Resumo Fundamento Qualidade de imagem e dose de radiação são otimizadas com uma frequência cardíaca (FC) lenta e estável na realização de imagens de artérias coronárias durante a angiografia cardíaca por tomografia computadorizada (CCTA, do inglês cardiac computed tomography angiography) A segurança, a eficácia e o protocolo para a redução da FC com medicamento betabloqueador ainda não foi bem descrita em uma população de pacientes pediátricos. Objetivo Oferecer um protocolo de dose de metoprolol eficiente a ser usado em pacientes pediátricos externos durante a CCTA. Métodos Realizamos uma revisão retrospectiva de todos os pacientes pediátricos externos que receberam o metoprolol durante a CCTA. As características demográficas e clínicas foram resumidas e a redução média em FC foi estimada utilizando-se um modelo de regressão linear multivariada. As imagens foram avaliadas em uma escala de 1 a 4 (1= ideal). Resultados Um total de 78 pacientes externos passaram a uma CCTA com o uso de metoprolol. A média de idade foi de 13 anos, a média de peso foi de 46 kg, e 36 pacientes (46%) eram do sexo masculino. As doses médias de metoprolol foram 1,5 (IQR 1,1; 1,8) mg/kg, e 0,4 (IQR 0,2; 0,7) mg/kg para administrações orais e intravenosas, respectivamente. O produto dose-comprimento por exame foi de 57 (IQR 30, 119) mGy*cm. A redução média da FC foi 19 (IQR 12, 26) batimentos por minuto, ou 23%. Não foram relatadas complicações ou eventos adversos. Conclusão O uso de metoprolol num cenário de pacientes pediátricos externos para redução da FC antes de uma CCTA é seguro e eficiente. Pode-se reproduzir um protocolo de dose de metoprolol quando for necessário atingir uma FC mais lenta, garantindo tempos de aquisição mais rápidos, imagens mais claras e redução na exposição à radiação nessa população. (Arq Bras Cardiol. 2021; 116(1):100-105)

Abstract Background Image quality and radiation dose are optimized with a slow, steady heart rate (HR) when imaging the coronary arteries during cardiac computed tomography angiography (CCTA). The safety, efficacy, and protocol for HR reduction with beta blocker medication is not well described in a pediatric patient population. Objective Provide a safe and efficient metoprolol dose protocol to be used in pediatric outpatients undergoing CCTA. Methods We conducted a retrospective review of all pediatric outpatients who received metoprolol during CCTA. Demographic and clinical characteristics were summarized and the average reduction in HR was estimated using a multivariate linear regression model. Images were evaluated on a 1-4 scale (1= optimal). Results Seventy-eight pediatric outpatients underwent a CCTA scan with the use of metoprolol. The median age was 13 years, median weight of 46 kg, and 36 (46%) were male. The median doses of metoprolol were 1.5 (IQR 1.1, 1.8) mg/kg and 0.4 (IQR 0.2, 0.7) mg/kg for oral and intravenous administrations, respectively. Procedural dose-length product was 57 (IQR 30, 119) mGy*cm. The average reduction in HR was 19 (IQR 12, 26) beats per minute, or 23%. No complications or adverse events were reported. Conclusion Use of metoprolol in a pediatric outpatient setting for HR reduction prior to CCTA is safe and effective. A metoprolol dose protocol can be reproduced when a slower HR is needed, ensuring faster acquisition times, clear images, and associated reduction in radiation exposure in this population. (Arq Bras Cardiol. 2021; 116(1):100-105)