Cardiac CT: Competition, complimentary or confounder.

Coronary CT angiography (CCTA) has been gradually adopted into clinical practice over the last two decades. CCTA has high diagnostic accuracy, prognostic value, and unique features such as assessment of plaque composition. CCTA-derived functional assessment techniques such as fractional flow reserve and CT perfusion are also available and can increase the diagnostic specificity of the modality. These properties propound CCTA as a competitor of functional testing in diagnosis of obstructive CAD, however, utilizing CCTA in a concomitant fashion to potentiate the performance of the latter can lead to better patient care and may provide more accurate prognostic information. Although multiple diagnostic challenges such as evaluation of calcified segments, stents, and small distal vessels still exist, the technologic developments in hardware as well as growing incorporation of artificial intelligence to daily practice are all set to augment the diagnostic and prognostic role of CCTA in cardiovascular disorders.

Multicenter Evaluation of the Feasibility of Clinical Implementation of SPECT Myocardial Blood Flow Measurement: Intersite Variability and Imaging Time.

BACKGROUND: Single-center studies have shown that single photon emission computed tomography myocardial blood flow (MBF) measurement is accurate compared with MBF measured with microspheres in a porcine model, positron emission tomography, and angiography. Clinical implementation requires consistency across multiple sites. The study goal is to determine the intersite processing repeatability of single photon emission computed tomography MBF and the additional camera time required. METHODS: Five sites (Canada, Italy, Japan, Germany, and Singapore) each acquired 25 to 35 MBF studies at rest and with pharmacological stress using technetium-99m-tetrofosmin on a pinhole-collimated cadmium-zinc-telluride-based cardiac single photon emission computed tomography camera with standardized list-mode imaging and processing protocols. Patients had intermediate to high pretest probability of coronary artery disease. MBF was measured locally and at a core laboratory using commercially available software. The time a room was occupied for an MBF study was compared with that for a standard rest/stress myocardial perfusion study. RESULTS: With motion correction, the overall correlation in MBF between core laboratory and local site was 0.93 (range, 0.87-0.97) at rest, 0.90 (range, 0.84-0.96) at stress, and 0.84 (range, 0.70-0.92) for myocardial flow reserve. The local-to-core difference in global MBF (bias-MBF) was 5.4% (-3.8% to 14.8%; median [interquartile range]) at rest and 5.4% (-6.2% to 19.4%) at stress. Between the 5 sites, bias-MBF ranged from -1.6% to 11.0% at rest and from -1.9% to 16.3% at stress; the interquartile range in bias-MBF was between 9.3% (4.8%-14.0%) and 22.3% (-10.3% to 12.0%) at rest and between 17.0% (-11.3% to 5.6%) and 33.3% (-10.4% to 22.9%) at stress and was not significantly different between most sites. Both bias and interquartile range were like previously reported interobserver variability and less than the SD of the test-retest difference of 30%. The overall difference in myocardial flow reserve was 1.52% (-10.6% to 11.3%). There were no significant differences between with and without motion correction. The average additional acquisition time varied between sites from 44 to 79 minutes. CONCLUSIONS: The average bias-MBF and bias-MFR values were small with standard deviations substantially less than the test-retest variability. This demonstrates that MBF can be measured consistently across multiple sites and further supports that this technique can be reliably implemented. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03427749.

The efficacy of inspiratory muscle training in patients with coronary artery disease: Protocol for a systematic review and meta-analysis.

BACKGROUND: Inspiratory muscle training (IMT) has been recognized as an effective form of training in patients with cardiovascular disease and heart failure. However, little is known about the efficacy of IMT in the treatment of patients with coronary artery disease (CAD). The aim of this systematic review will be to evaluate randomized controlled studies to understand the effect of IMT on CAD patients. METHOD: We will include randomized controlled trials evaluating the efficacy of IMT in patients 18 years and older diagnosed with CAD. Crossover trials, cluster-randomized, quasi-randomized, and non-randomized trials will be excluded. Study search will be conducted in major databases (MEDLINE, the Cochrane Central Register of Controlled Trials, Embase, and PEDro). The study intervention will be IMT independent of the duration, frequency, or intensity of training. The primary outcome will be quality of life, patient-reported health status, and all adverse events related to IMT. Secondary outcomes will include exercise capacity and respiratory muscle strength. The risk of bias will be evaluated based on the Cochrane Risk of Bias tool. Screening, data extraction, and quality assessment will be performed by two independent reviewers. If two or more studies are considered to be clinically homogeneous, a meta-analysis based on the random-effects model will be performed. The quality of evidence will be evaluated based on the GRADE approach. CONCLUSION: This systematic review will improve our understanding of the effects of IMT on CAD patients and potentially establish IMT as an alternative form of exercise training for the treatment of CAD. TRIAL REGISTRATION: Study registration. OSF registries (https://osf.io/3ch7m). Date registered: May 10, 2022. Registration DOI: https://doi.org/10.17605/OSF.IO/GVMY7.

The estimation of left ventricular function using prospective ECG-triggered coronary CT angiography.

BACKGROUND: Coronary computed tomography angiography (CCTA) is vital for diagnosing coronary artery disease; however, prospective ECG-triggered acquisition, minimizing radiation exposure, limits left ventricular (LV) ejection fraction (EF) evaluation. We aimed to assess the feasibility and utility of LVEF100msec, a new index for estimating LV function using volumetric changes during 100 msec within systole. METHODS: This retrospective study analyzed patients who underwent prospective ECG-triggered CCTA with systolic acquisition between January 2015 and June 2022. The LVEF100msec was calculated using the maximum and minimum LV volumes among the three phases (300, 350, and 400 msec post-QRS) and expressed as a percentage. Patients were classified into normal, mild-moderately reduced, or severely reduced LV function categories based on the reference test. The LVEF100msec was compared among groups, and the optimal cutoff value of LVEF100msec for predicting severe LV dysfunction was investigated. RESULTS: The study included 271 patients (median age â€‹= â€‹58 years, 52% male). LVEF was normal in 188 (69.4%), mild-moderately reduced in 57 (21.0%), and severely reduced in 26 (9.6%) patients. Median LVEF100msec value was 9.0 (6.7-12.6) for normal LV function, 4.7 (3.1-8.8) for mild-moderately reduced, and 2.9 (1.5-3.8) for severely reduced LV function. LVEF100msec values significantly differed among categories (p â€‹< â€‹0.001). The optimal LVEF100msec cutoff for severe LV dysfunction was 4.3%, with an AUC of 0.924, sensitivity of 88%, and specificity of 89%. CONCLUSION: The LVEF100msec may serve as a valuable indicator of severe LV dysfunction.

Utility of FFRCT in Patients with Chest Pain.

PURPOSE OF REVIEW: The goal of this article is to review the data supporting the use of fractional flow reserve derived from coronary computed tomography angiography (FFRCT) in patients with chest pain. REVIEW FINDINGS: Numerous clinical trials have demonstrated that the diagnostic accuracy of coronary computed tomography angiography (CCTA) can be improved with the use of FFRCT, primarily due to its superior specificity when compared to CCTA alone. This promising development may help reduce the need for invasive angiography in patients presenting with chest pain. Furthermore, some studies have indicated that incorporating FFRCT into decision-making is safe, with an FFRCT value of ≥ 0.8 being associated with favorable outcomes. While FFRCT has been shown to be feasible in patients with acute chest pain, further large-scale studies are warranted to confirm its utility. The emergence of FFRCT as a tool for the management of patients with chest pain is promising. However, potential limitations require the interpretation of FFRCT in conjunction with clinical context.

Advances in Single-Photon Emission Computed Tomography: Hardware, Software, and Myocardial Flow Reserve.

The clinical presentation of coronary artery disease (CAD) has changed during the last 20 years with less ischemia on stress testing and more nonobstructive CAD on coronary angiography. Single-photon emission computed tomography (SPECT) myocardial perfusion imaging should include the measurement of myocardial flow reserve and assessment of coronary calcium for the diagnosis of nonobstructive CAD and coronary microvascular disease. SPECT/CT systems provide reliable attenuation correction for better specificity and low-dose CT for coronary calcium evaluation. SPECT MFR measurement is accurate, well validated, and repeatable.

Left ventricular hypertrophy as a predictor of cardiovascular outcomes after transcatheter aortic valve replacement.

AIMS: This study aimed to clarify the relationship between cardiovascular prognosis and left ventricular hypertrophy (LVH) in patients with severe aortic stenosis who underwent transcatheter aortic valve replacement (TAVR) and to investigate the relationship between cardiac sympathetic nerve (CSN) function and these factors using 123 I-metaiodobenzylguanidine scintigraphy. METHODS AND RESULTS: In this single-centre, retrospective observational study, 349 patients who underwent TAVR at our institution between July 2017 and May 2020 were divided into two groups: those with severe LVH pre-operatively [severe LVH (+) group] and those without LVH pre-operatively [severe LVH (-) group]. The rates of freedom from cardiovascular events (cardiovascular death and heart failure hospitalization) were compared. The relationship between changes in left ventricular mass index (LVMi) and changes in delay heart-mediastinum ratio (H/M) from before TAVR to 6 months after TAVR was also investigated. The event-free rate was significantly lower in the severe LVH (+) group (87.1% vs. 96.0%, log-rank P = 0.021). The severe LVH (+) group exhibited a significantly lower delay H/M value, scored by 123 I-metaiodobenzylguanidine scintigraphy, than the severe LVH (-) group (2.33 [1.92-2.67] vs. 2.67 [2.17-3.68], respectively, P < 0.001). Moreover, the event-free rate of post-operative cardiovascular events was lower among patients with a delay H/M value < 2.50 than that among other patients (87.7% vs. 97.2%, log-rank P = 0.012). LVMi was significantly higher (115 [99-130] vs. 90 [78-111] g/m2 , P < 0.001) and delay H/M value was significantly lower (2.53 [1.98-2.83] vs. 2.71 [2.25-3.19], P = 0.025) in the severe LVH (+) group than in the severe LVH (-) group at 6 months after TAVR. Patients with improved LVH at 6 months after TAVR also had increased delay H/M (from 2.51 [2.01-2.81] to 2.67 [2.26-3.02], P < 0.001), whereas those without improved LVH had no significant change in delay H/M (from 2.64 [2.23-3.06] to 2.53 [1.97-3.00], P = 0.829). CONCLUSIONS: Severe LVH before TAVR is a prognostic factor for poor post-operative cardiovascular outcomes. LVH associated with aortic stenosis and CSN function are correlated, suggesting their involvement in LVH prognosis.

Evaluation of Lung Glucose Uptake with Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/CT in Patients with Pulmonary Arterial Hypertension and Pulmonary Hypertension Due to Left Heart Disease.

Aim: Previous studies have demonstrated increased glucose uptake by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in lung parenchyma in animal models or small pulmonary arterial hypertension (PAH) cohorts. However, it is not well known whether increased FDG uptake in the lung is a unique phenomenon in PAH or whether elevated pulmonary artery pressure (PAP) induces FDG uptake. Methods and results: Nineteen patients with PAH, 8 patients with pulmonary hypertension due to left heart disease (PH-LHD), and 14 age matched control subjects were included. All PH patients underwent right heart catheterization and FDG-PET. The mean standard uptake value (SUV g/mL) of FDG in each lung was obtained and average values of both lungs were calculated as mean lung FDG SUV. The correlation between hemodynamics and mean lung FDG SUV was also analyzed in PH patients. Mean PAP (mPAP) was not significantly different between PAH and PH-LHD (45±11 vs 43±5 mmHg, p=0.51). PAH patients demonstrated significantly increased mean lung FDG SUV compared with PH-LHD and controls (PAH: 0.76±0.26 vs PH-LHD: 0.51±0.12 vs controls: 0.53±0.16, p=0.0025). The mean lung FDG SUV did not correlate with mPAP either in PAH or PH-LHD. Conclusion: PAH is associated with increased lung FDG uptake indicating increased glucose utilization in the lung. This may represent metabolic shift to glycolysis and/or active inflammation in the remodeled pulmonary vasculature, and is observed to a greater extent in PAH than in patients with PH secondary to LHD and control subjects without PH.

Cystatin C in risk prediction after transcatheter aortic valve replacement: a retrospective analysis.

AIMS: No study has evaluated the prognostic value of the chronic kidney disease (CKD) classification by cystatin C-based estimated glomerular filtration rate (eGFR) (CKDCys classification) in patients undergoing transcatheter aortic valve replacement (TAVR). This study aimed to compare the prognostic value of CKDCys classification and CKD classification by creatinine-based eGFR (CKDCr classification) in risk prediction after TAVR. METHODS AND RESULTS: We retrospectively analysed consecutive 219 patients with symptomatic severe aortic stenosis who underwent TAVR at our institute between December 2016 and June 2019. Pre-operative CKDCr and CKDCys classifications were evaluated for their prognostic value of 2-year major adverse cardiovascular and cerebrovascular events (MACCE) after TAVR. MACCE was defined as the composite of all-cause mortality, non-fatal myocardial infarction, stroke, and rehospitalization for worsening congestive heart failure. Participants had a median age of 86.0 years and were predominantly female (76.9%). In 96.6% of the cases, TAVR was performed using transfemoral access. The median creatinine-based eGFR (52.85 mL/min/1.73 m2 ) was higher than the cystatin C-based eGFR (41.50 mL/min/1.73 m2 ). Downward reclassification in CKD stages based on eGFRCys was observed in 49.0% of patients. During a median follow-up period of 575.5 (interquartile range: 367.0-730.0) days, 58 patients presented with MACCE. CKDCys classification, but not CKDCr classification, significantly stratified the risk of 2-year MACCE in patients after TAVR by log-rank test (P = 0.003). In multivariate Cox regression analysis, only CKDCys stage 3b [hazard ratio (HR) = 4.37; 95% confidence interval (CI): 1.28-14.91; P = 0.019] and CKDCys stage 4 + 5 (HR = 3.72; 95% CI: 1.06-12.99; P = 0.040) were significant predictors of MACCE after adjustment for potential confounders. CONCLUSIONS: The CKDCys classification could better assess the risk than the CKDCr classification in patients undergoing TAVR. CKDCys stage 3b and stage 4 + 5 correlated with adverse outcomes.

Incidence and predictors of transcatheter aortic valve replacement device emboligenic matter detected by transesophageal echocardiography.

During transfemoral (TF) or transcatheter aortic valve replacement (TAVR), transesophageal echocardiography (TEE) sometimes reveals an unexpected mobile membranous mass on the catheter tip within the proximal part of the descending thoracic aorta. Such mobile masses may cause critical embolic events if the TAVR device advances into the ascending aorta in the absence of preventive measures. This study aimed to investigate the incidence and predictors of emboligenic matter (EM) during TAVR, impact of EM on the procedure, and incidence of symptomatic ischemic stroke post procedure. Among 436 consecutive patients who underwent TF-TAVR, 407 were evaluated in this study. The primary end point was incidence of symptomatic ischemic stroke within 24 h post procedure while taking appropriate preventive measures. Incidence of EM, factors associated with EM, and the impact of EM on the procedure were also investigated. Among the 407 cases, 15 cases (3.7%) of EM were identified but no ischemic stroke occurred in the EM (+) group (0% vs. 2.04%, p = 1.00). In the EM (+) group, a self-expandable valve was used in all 15 cases (100% vs. 42.6%, p < 0.0001) while 14 cases used a CoreValve's InLine sheath system initially (93.3% vs. 27.3%, p < 0.0001). CoreValve's InLine sheath system usage was the only independent predictor of EM. The CoreValve's InLine delivery system was identified as a predictor of EM during TF-TAVR, but symptomatic ischemic stroke was avoided while taking appropriate embolization preventive measures.

Serial changes in cardiac sympathetic nervous function after transcatheter aortic valve replacement: A prospective observational study using 123I-meta-iodobenzylguanidine imaging.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) can rapidly improve cardiac sympathetic nervous function (CSNF) within 2 weeks in patients with aortic stenosis (AS). However, whether such short-term improvements will be sustained thereafter remains unclear. METHODS: Patients with severe AS who underwent TAVR between October 2017 and June 2019 were enrolled in this single-center, prospective, observational study. 123I-meta-iodobenzylguanidine imaging was performed at baseline, within 2 weeks after TAVR, and at 6 to 12 months post-TAVR to evaluate the heart-mediastinum ratio (H/M) and washout rate. RESULTS: Of 183 consecutive patients, 75 (19 men; median age: 86 years) were evaluated. The late H/M significantly improved within 2 weeks after TAVR (P = .041) and further improved over 6 to 12 months after TAVR (P = .041). Multivariate analysis revealed that the baseline mean aortic valve pressure gradient (mPG) was an independent predictor of mid-term improvement in the late H/M (> 0.1) (P = .037). Patients with a high baseline mPG (≥ 58 mmHg) exhibited a significantly greater increase in the late H/M than those with a low baseline mPG (< 42 mmHg) (0.24 vs 0.01; P = .029). CONCLUSION: CSNF demonstrated sustained improvement from within 2 weeks after TAVR until 6 to 12 months later. Such improvement was related to baseline hemodynamic AS severity.

Thrombotic Lesions are Associated with Poor Outcomes after Endovascular Treatment in Patients with Non-Acute Aortoiliac Total Occlusions.

AIM: The post-endovascular treatment outcomes of thrombotic lesions remain unclear. This study aimed to investigate the effects of thrombotic lesions on post-endovascular treatment outcomes in patients with non-acute aortoiliac total occlusions. METHODS: This subanalysis of a multicenter prospective observational registry study included patients from 64 institutions in Japan between April 2014 and April 2016. A total of 346 patients (394 limbs; median age, 72 years), including 186 men, underwent endovascular treatment for non-acute aortoiliac total occlusions and were included. The patients were classified as having thrombotic or non-thrombotic lesions. The primary (1-year primary patency rate) and secondary (1-year overall survival rate) endpoints were evaluated. RESULTS: Thrombotic lesions were identified in 18.5% (64/346) of the patients. The 1-year primary patency (85.9% versus 95.4%, log-rank p＜.001) and overall survival (90.6% versus 97.9%, log-rank p=.003) rates were significantly lower in the thrombotic group than in the non-thrombotic group. Thrombotic lesions had significant effects on the post-endovascular treatment outcomes, with adjusted hazard ratios of 3.91 (95% confidence interval, 1.64-9.34, p=.002) for primary patency and 4.93 (95% confidence interval, 1.59-15.3, p=.006) for all-cause mortality. CONCLUSIONS: Thrombotic lesions were associated with 1-year restenosis and all-cause mortality after endovascular treatment for non-acute aortoiliac total occlusions. Endovascular treatment strategies should be carefully planned for patients with thrombotic lesions.

Prognostic value of cardiac 123 I-metaiodobenzylguanidine imaging for predicting cardiac events after transcatheter aortic valve replacement.

AIMS: In patients with aortic valve stenosis (AS), cardiac sympathetic nervous (CSN) dysfunction and its improvement after transcatheter aortic valve replacement (TAVR) have been reported. The prognostic impact of CSN function remains unclear. This study investigated the prognostic value of cardiac 123 I-metaiodobenzylguanidine (MIBG) imaging for predicting cardiac events after TAVR. METHODS AND RESULTS: This single-centre prospective observational study enrolled patients with AS between July 2017 and May 2019. MIBG scintigraphy was performed before and soon after TAVR to evaluate the late heart-mediastinum ratio (L-H/M). Patients were classified into three pairs of groups based on the baseline and post-TAVR L-H/M (≥2.0 or <2.0) and on the presence of TAVR-related improvement in L-H/M. The study endpoint was the occurrence of major adverse cardiac events (MACE), defined as a composite of all-cause death, non-fatal myocardial infarction, and hospitalization due to heart failure. Among the 187 consecutive patients who underwent TAVR, 107 (27 men; median age: 86 years) were evaluated. Over a median follow-up of 366 days, 15 (14.0%) patients had MACE. The incidence of MACE was significantly low in patients with L-H/M improvement and/or high post-TAVR L-H/M (≥2.0). Baseline L-H/M and frailty were associated with poor response of L-H/M to TAVR treatment. TAVR-related improvement in L-H/M had significant effects on MACE, with an adjusted hazard ratio of 0.233 (95% confidence interval, 0.064-0.856; P = 0.028). CONCLUSIONS: TAVR-related improvement in L-H/M was an independent predictor of cardiac events, 1 year after TAVR. Cardiac MIBG imaging is useful for predicting cardiac events after TAVR.