Prognostic value of myocardial flow reserve derived by quantitative SPECT for patients with intermediate coronary stenoses.

BACKGROUND:Functional assessment of myocardial ischemia is critical for patients with intermediate coronary stenosis. As the diagnosis performance of absolute quantification of myocardial blood flow (MBF) and myocardial flow reserve (MFR) by single-photon emission tomography (SPECT) has been proven, its prognostic value in patients with intermediate coronary stenosis remains to be evaluated.METHODS:Patients with one or more target lesions of ≥ 50% to ≤ 80% diameter stenoses on invasive coronary angiography were prospectively included in this study. All patients were scheduled for clinically indicated SPECT myocardial perfusion imaging (MPI) within 3 months and agreed to provide informed consent to participate in quantitative SPECT acquisitions to obtain MBF and MFR values. The primary endpoint was defined as a composite of the major adverse cardiac events (MACE): Cardiac death, myocardial infarction, late revascularization and heart failure or unstable angina-related rehospitalization.RESULTS:One hundred and nineteen patients (mean age 57 ± 8 years, 62.2% men) were included in the analysis. The average lumen stenosis of patients was 67.0 ± 10.4%. Over a median follow-up duration of 1408 days (interquartile range 1297-1666 days), 18 patients (15.1%) had MACE. Patients with impaired MFR (MFR < 2) had a significantly higher incidence of events than those with preserved MFR (MFR ≥ 2) in Kaplan-Meier survival analysis (Log-rank = 8.105, P = 0.004), while no significant difference was found between patients with normal relative perfusion and those with relative perfusion abnormalities (log-rank = 0.098, P > 0.05). In a multivariate Cox hazards analysis, the SPECT-derived MFR remained an independent predictor of MACE (HR 0.352, 95% CI 0.145-0.854, P = 0.021).CONCLUSIONS:In a cohort of patients with angiographic intermediate coronary lesions, SPECT-derived MFR was an independent predictor of prognosis.

Frequency and Size of In Situ Thrombus Within Patent Foramen Ovale.

BACKGROUND:High-resolution optical coherence tomography can detect in situ thrombi within patent foramen ovale (PFO), which can become a dangerous embolic source. This study aimed to investigate the frequency and size of in situ thrombus within PFO using optical coherence tomography.METHODS:The cross-sectional study was conducted at Fuwai Hospital (Beijing, China) between 2020 and 2021. From 528 consecutive patients with PFO, 117 (age, 34.33 [SD, 11.30] years) without known vascular risk factors were included; according to PFO-related symptoms, they were divided into the stroke (n=43, including 5 patients with transient ischemic attack), migraine (n=49) and asymptomatic (n=25) groups. Optical coherence tomography was used to evaluate in situ thrombi and abnormal endocardium within PFO. Univariable analysis and a logistic model were used to evaluate the association between stroke and in situ thrombus; age, sex, body mass index, and antithrombotic therapy were included as covariates.RESULTS:Antithrombotic therapy was used more frequently in the stroke group than in the migraine group (76.7% versus 12.2%; P<0.001). In situ PFO thrombi were detected in 36 (83.7%), 28 (57.1%), and 0 (0.0%) patients from the stroke, migraine, and asymptomatic groups, respectively (P<0.001). Between the stroke and migraine groups, there was no significant difference in the median (interquartile range) thrombus number per patient (7 [3-12] versus 2 [0-10]; P=0.199), maximum thrombus diameter (0.35 [0.20-0.46] versus 0.21 [0-0.68] mm; P=0.597), or total thrombus volume (0.02 [0.01-0.05] versus 0.01 [0-0.05] mm3; P=0.386). Additionally, in situ thrombus was significantly associated with stroke risk (odds ratio, 4.59 [95% CI, 1.26-16.69]). Abnormal endocardium within PFO occurred in patients with in situ thrombi (71.9%) but not in those without. During optical coherence tomography examination, migraine occurred in 2 patients with in situ thrombi.CONCLUSIONS:The frequency of in situ thrombus was extremely high in stroke and migraine groups, while none of the asymptomatic individuals presented with an in situ thrombus. In situ thrombus formation may play a role in patients with PFO-associated stroke or migraines and have therapeutic implications.REGISTRATION:URL: https://www.CLINICALTRIALS:gov; Unique identifier: NCT04686253.

68Ga-FAPI PET/CT for molecular assessment of fibroblast activation in right heart in pulmonary arterial hypertension: a single-center, pilot study.

BACKGROUND:Positron emission tomography (PET) imaging with radiolabeled fibroblasts activation protein inhibitor (FAPI) provides the opportunity to directly visualize fibrosis. This study aimed to investigate the feasibility of 68Ga-FAPI PET imaging in assessing right ventricular (RV) fibrotic remodeling and the relationship between FAPI uptake with parameters of pulmonary hemodynamics and cardiac function in pulmonary arterial hypertension (PAH) patients.METHODS:In this pilot study, sixteen PAH patients were enrolled to participate in cardiac 68Ga-FAPI PET/CT imaging. All patients underwent right heart catheterization and echocardiography for assessment of pulmonary hemodynamics and cardiac function within seven days. Cardiac FAPI uptake was visually assessed and quantified as maximum standardized uptake value (SUVmax).RESULTS:Twelve PAH patients exhibited FAPI uptake in RV free wall and insertion point. The overall activity of FAPI accumulated in the RV free wall (SUVmax: 2.5 ± 1.8, P < 0.001) and insertion point (SUVmax:2.5 ± 1.7, P < 0.001) was significantly upregulated compared to left ventricle (SUVmax:1.5 ± 0.5). Patients with tricuspid annular plane systolic excursion (TAPSE) < 17 mm presented significantly higher uptake than those with TAPSE ≥ 17 mm in both RV free wall (SUVmax: 3.4 ± 1.9 vs 1.7 ± 1.1, P = 0.010) and insertion point (SUVmax: 3.4 ± 1.9 vs 1.6 ± 0.7, P = 0.028), indicating RV uptake of FAPI was associated with RV dysfunction. There was significant positive correlation between cardiac FAPI uptake and total pulmonary resistance and the level of N-terminal pro b-type natriuretic peptide.CONCLUSIONS:68Ga-FAPI PET/CT imaging is feasible to directly visualize fibrotic remodeling of RV in patients with PAH.

Diagnostic value of quantitative myocardial blood flow assessment by NaI(Tl) SPECT in detecting significant stenosis: a prospective, multi-center study.

OBJECTIVES:The aim of this prospective multi-center study was to investigate the diagnostic value of myocardial blood flow (MBF) quantification using NaI(Tl)-based single-photon emission computed tomography (SPECT) for determining coronary artery disease (CAD) defined by quantitative coronary angiography (QCA).BACKGROUND:Absolute quantitation of MBF and myocardial flow reserve (MFR) using SPECT is clinically feasible; however, whether flow quantification using NaI(Tl) SPECT is superior to commonly performed SPECT myocardial perfusion imaging (MPI) in determining CAD has not been evaluated.METHODS:Patients with suspected or known CAD underwent pharmacological stress/rest dynamic SPECT imaging and routine SPECT MPI followed by QCA. Obstructive disease was defined as ≥ 50% reduction in luminal diameter on QCA.RESULTS:One hundred fifty-four patients (462 vessels) were included in the analysis. Obstructive CAD was detected in 76/154 patients (49.4%) and 112/462 vessels (24.2%). Optimal cut-off values were 1.86 mL/min/g for stress MBF and 1.95 for MFR, respectively. Stress MBF and MFR were more sensitive than MPI in both individual patients (stress MBF vs MPI: 81.6% vs 51.3%; MFR vs MPI: 72.4% vs 51.3%) and in coronary vascular regions (stress MBF vs MPI: 78.6% vs 31.3%; MFR vs MPI: 75.9% vs 31.3%; all P < .01). In receiver operating characteristic curve analysis, quantification revealed a significantly greater area under the curve than MPI at the patient (stress MBF vs MPI: 0.761 vs 0.641; MFR vs MPI: 0.770 vs 0.641) and the vessel (stress MBF vs MPI: 0.745 vs 0.613; MFR vs MPI: 0.756 vs 0.613; all P < .05) levels. Integrating quantitative SPECT measures with MPI significantly increased the area under the curve and improved the discriminatory and reclassification capacity.CONCLUSION:Flow quantification using NaI(Tl) SPECT provides superior sensitivity and discriminatory capacity to MPI in detecting significant stenosis. Clinical trial registration NCT03637725.

The value of ventilation/perfusion scanning and CT pulmonary angiography in predicting chronic thromboembolic pulmonary hypertension after acute pulmonary embolism: a one-year follow-up study.

To investigate the value of ventilation/perfusion (V/Q) scanning and CT pulmonary angiography (PA) in predicting CTEPH development after acute pulmonary embolism (APE). This study was performed in APE patients who had undergone both V/Q and CT PA after 3-month anticoagulation. The residual pulmonary obstructions were assessed based on V/Q and CT PA, and then recorded as pulmonary perfusion detect score (PPDs) and CT pulmonary artery obstruction index (PAOI). The predictive performance of PPDs and CT PAOI for CTEPH were determined and risk factors for predicting CTEPH development were identified. A total of 235 patients with initial diagnosis of APE were included in this study. ROC analysis showed that the AUCs of the PPDs and CT PAOI were 0.957 and 0.895, with corresponding cut-off values of 20.50% and 17.50% for predicting CTEPH development. Neither sensitivity nor specificity differed significantly between PPDs and CT PAOI (Sensitivity: 92.00% vs. 80.00%, P = 0.25; Specificity: 88.10% vs. 89.52%, P = 0.69). The univariable and multivariable logistic regression analysis demonstrated that pulmonary arterial hypertension confirmed by echocardiography at initial APE diagnosis (OR: 6.16, 95%CI: 1.31-29.02, P = 0.02), a PPDs of > 20.50% (OR: 22.95, 95%CI: 2.37-222.19, P = 0.007), and a CT PAOI of > 17.50% (OR: 9.98, 95%CI: 2.06-48.49, P = 0.004) were associated with CTEPH development. Both V/Q and CT PA after 3-month anticoagulation for APE showed great performance in predicting CTEPH development, and V/Q scanning has a tendency to be more sensitive but less specific than CT PA. The residual pulmonary embolism detected by V/Q and CT PA was associated with an increased risk of CTEPH development.

Predictive value of SPECT myocardial perfusion imaging in patients with unrevascularized coronary chronic total occlusion.

OBJECTIVE:Data involved the association between myocardial ischaemia and the outcome for unrevascularized coronary chronic total occlusion (CTO) patients were limited. The purpose of this study was to evaluate the predictive value of ischaemia detected by single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for the adverse events in unrevascularized CTO patients. We further explored whether ischaemia generated from CTO vessel can independently predict the outcome.METHODS:Patients with at least one unrevascularized CTO on coronary angiography were enrolled in this study. Exercise stress/rest SPECT MPI was performed in all patients. All patients were then followed by telephone interview and reviewing of medical records.RESULTS:Patients with ischaemia experienced significantly higher rate of adverse events than non-ischaemia patients (40.7% vs 7.1%, P = 0.002). Ischaemia demonstrated on MPI [odds ratio (OR) = 7.656; 95% confidence interval (CI) 1.598-36.677; P = 0.011] was an independent predictor for adverse events. Moreover, CTO-ischaemia (OR = 5.466; 95% CI 1.015-29.420; P = 0.048), non-CTO ischaemia (OR = 29.174; 95% CI 3.245-262.322; P = 0.003), mixed-ischaemia (OR = 7.130, 95% CI 1.257-40.445; P = 0.027) were all independent predictors for outcome.CONCLUSION:Ischaemia demonstrated on MPI, especially CTO-ischaemia were independent predictors for the adverse events. SPECT MPI can aid to identify patients at risk of adverse events, who may benefit from subsequent CTO percutaneous coronary intervention.

First in-human modified atrial septostomy combining radiofrequency ablation and balloon dilation.

OBJECTIVE:Preclinical research suggests that the combined use of radiofrequency ablation and balloon dilation (CURB) could create stable interatrial communications without device implantation. This study examined the first in-human use of CURB for modified atrial septostomy in patients with severe pulmonary arterial hypertension (PAH).METHODS:Between July 2018 and October 2021, CURB was performed in 19 patients with severe PAH (age: 31.5±9.1 years; mean pulmonary artery pressure: 73 mm Hg (IQR: 66-92); pulmonary vascular resistance: 18.7 Wood units (IQR: 17.8-23.3)). Under guidance of intracardiac echocardiography and three-dimensional location system, (1) fossae ovalis was reconstructed and ablated point-by-point with radiofrequency; (2) then graded balloon dilation was performed after transseptal puncture and the optimal size was determined according to the level of arterial oxygen saturation (SatO2); (3) radiofrequency ablation was repeated around the rims of the created fenestration. The interatrial fenestrations were followed-up serially.RESULTS:After CURB, the immediate fenestration size was 4.4 mm (IQR: 4.1-5.1) with intracardiac echocardiography, systolic aortic pressure increased by 10.2±6.9 mm Hg, cardiac index increased by 0.7±0.3 L/min/m2 and room-air resting SatO2 decreased by 6.2±1.9% (p<0.001). One patient experienced increased pericardiac effusion postoperatively; the others had no complications. On follow-up (median: 15.5 months), all interatrial communications were patent with stable size (intraclass correlation coefficient=0.96, 95%CI:0.89 to 0.99). The WHO functional class increased by 1 (IQR: 1-2) (p<0.001) with improvement of exercise capacity (+159.5 m, P<0.001).CONCLUSION:The interatrial communications created with CURB in patients with severe PAH were stable and the mid-term outcomes were satisfactory.TRIAL REGISTRATION NUMBER:NCT03554330.

68Ga-FAPI right heart uptake in a patient with idiopathic pulmonary arterial hypertension.

Sex-specific reference limits of left ventricular ejection fraction and volumes estimated by gated myocardial perfusion imaging for low-risk patients in China: a comparison between three quantitative algorithms.

BACKGROUND:Establishing appropriate reference value limits of left ventricular (LV) functional parameters is fundamental for the assessment of cardiac function. At present, there are no reports aimed at establishing reference limits using gated myocardial perfusion imaging (MPI) in mainland China.METHODS:A total of 175 consecutive patients who were defined as low-risk coronary artery disease patients underwent stress Technetium-99m sestamibi (99mTc-MIBI)-gated myocardial perfusion single-photon emission computed tomography (SPECT) imaging. The LV ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) were obtained by 3 quantitative algorithms: quantitative-gated SPECT, emory cardiac toolbox, and 4-dimensional model SPECT, respectively. The threshold values were obtained using Gaussian distribution or percentiles. The influence of gender, age, and weight on cardiac functional parameters was analyzed by multiple regressions for linear models.RESULTS:For males, the lower reference limits of EF were 52%, 63%, and 58%, respectively; and the upper limits of EDV/ESV were 106/45, 152/55, and 135/55 mL, respectively. For females, the lower reference limits of EF were 58%, 66%, and 65%, respectively; and the upper limits of EDV/ESV were 73/27, 105/31, and 88/29 mL, respectively. Compared to females, males had greater cardiac volume values and lower mean EF values. Bland-Altman plots revealed that the cardiac function parameters calculated by the three quantitative algorithms were in high agreement.CONCLUSIONS:In this study, the reference limits of cardiac parameters calculated by the 3 methods based on single-center data in China were preliminarily established. The threshold values determined by three quantitative algorithms were not interchangeable but were highly correlated.

Ventilation/perfusion imaging predicts response to balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension.

OBJECTS:Although balloon pulmonary angioplasty (BPA) has emerged as an alternative treatment option for chronic thromboembolic pulmonary hypertension (CTEPH), it is followed in some patients by residual PH. We studied the efficacy of BPA on pulmonary blood flow and the predictive value of ventilation/perfusion (V/Q) scanning.METHODS:We retrospectively reviewed the clinical database, which included patients diagnosed with CTEPH who had received BPA. All patients undergone V/Q scanning to quantify the extent of pulmonary perfusion abnormality before and after BPA. Pulmonary hemodynamics were assessed by right heart catheterization, and cardiac function and exercise capacity were evaluated at baseline and post-BPA. A total of 120 CTEPH patients were included for analysis.RESULTS:BPA significantly alleviated mean pulmonary arterial pressure (mPAP: 48.0 ± 12.9 mmHg vs 34.7 ± 10.3 mmHg, P < 0.001) and pulmonary vascular resistance (PVR: 8.8 ± 4.1 Wood units vs 5.2 ± 3.0 Wood units, P < 0.001), and improved cardiac function (N-terminal pro B-type natriuretic peptide: 1628.7 ± 2887.2 pg/mL vs 400.4 ± 669.3 pg/mL, P < 0.001) and exercise capacity (6-minute walking distance: 386 ± 122 m vs 461 ± 86 m, P < 0.001). The extent of pulmonary perfusion abnormality represented by the percentage of perfusion defects (PPDs%) was improved after BPA (50.1 ± 13.6 vs 35.6 ± 14.2, P < 0.001), with the right and inferior lung lobes benefitting the most. PPDs% < 35.5 at baseline and greater restoration of PPDs% after BPA (∆PPDs% > 20.6) were associated with a better response to BPA (PPDs% < 35.5: odds ratio [OR] 10.857, 95% confidence interval [95%CI] 1.393-84.635, P = 0.023; ∆PPDs% > 20.6: OR 1.035, 95% CI 1.002-1.068, P = 0.036).CONCLUSION:BPA significantly restored pulmonary blood flow, predominantly in the right and inferior lobes. V/Q scanning has the potential to predict the therapeutic response to BPA for CTEPH.

Prognostic value of myocardial flow reserve derived by quantitative SPECT for patients with intermediate coronary stenoses.

BACKGROUND:Functional assessment of myocardial ischemia is critical for patients with intermediate coronary stenosis. As the diagnosis performance of absolute quantification of myocardial blood flow (MBF) and myocardial flow reserve (MFR) by single-photon emission tomography (SPECT) has been proven, its prognostic value in patients with intermediate coronary stenosis remains to be evaluated.METHODS:Patients with one or more target lesions of ≥ 50% to ≤ 80% diameter stenoses on invasive coronary angiography were prospectively included in this study. All patients were scheduled for clinically indicated SPECT myocardial perfusion imaging (MPI) within 3 months and agreed to provide informed consent to participate in quantitative SPECT acquisitions to obtain MBF and MFR values. The primary endpoint was defined as a composite of the major adverse cardiac events (MACE): Cardiac death, myocardial infarction, late revascularization and heart failure or unstable angina-related rehospitalization.RESULTS:One hundred and nineteen patients (mean age 57 ± 8 years, 62.2% men) were included in the analysis. The average lumen stenosis of patients was 67.0 ± 10.4%. Over a median follow-up duration of 1408 days (interquartile range 1297-1666 days), 18 patients (15.1%) had MACE. Patients with impaired MFR (MFR < 2) had a significantly higher incidence of events than those with preserved MFR (MFR ≥ 2) in Kaplan-Meier survival analysis (Log-rank = 8.105, P = 0.004), while no significant difference was found between patients with normal relative perfusion and those with relative perfusion abnormalities (log-rank = 0.098, P > 0.05). In a multivariate Cox hazards analysis, the SPECT-derived MFR remained an independent predictor of MACE (HR 0.352, 95% CI 0.145-0.854, P = 0.021).CONCLUSIONS:In a cohort of patients with angiographic intermediate coronary lesions, SPECT-derived MFR was an independent predictor of prognosis.

Frequency and Size of In Situ Thrombus Within Patent Foramen Ovale.

BACKGROUND:High-resolution optical coherence tomography can detect in situ thrombi within patent foramen ovale (PFO), which can become a dangerous embolic source. This study aimed to investigate the frequency and size of in situ thrombus within PFO using optical coherence tomography.METHODS:The cross-sectional study was conducted at Fuwai Hospital (Beijing, China) between 2020 and 2021. From 528 consecutive patients with PFO, 117 (age, 34.33 [SD, 11.30] years) without known vascular risk factors were included; according to PFO-related symptoms, they were divided into the stroke (n=43, including 5 patients with transient ischemic attack), migraine (n=49) and asymptomatic (n=25) groups. Optical coherence tomography was used to evaluate in situ thrombi and abnormal endocardium within PFO. Univariable analysis and a logistic model were used to evaluate the association between stroke and in situ thrombus; age, sex, body mass index, and antithrombotic therapy were included as covariates.RESULTS:Antithrombotic therapy was used more frequently in the stroke group than in the migraine group (76.7% versus 12.2%; P<0.001). In situ PFO thrombi were detected in 36 (83.7%), 28 (57.1%), and 0 (0.0%) patients from the stroke, migraine, and asymptomatic groups, respectively (P<0.001). Between the stroke and migraine groups, there was no significant difference in the median (interquartile range) thrombus number per patient (7 [3-12] versus 2 [0-10]; P=0.199), maximum thrombus diameter (0.35 [0.20-0.46] versus 0.21 [0-0.68] mm; P=0.597), or total thrombus volume (0.02 [0.01-0.05] versus 0.01 [0-0.05] mm3; P=0.386). Additionally, in situ thrombus was significantly associated with stroke risk (odds ratio, 4.59 [95% CI, 1.26-16.69]). Abnormal endocardium within PFO occurred in patients with in situ thrombi (71.9%) but not in those without. During optical coherence tomography examination, migraine occurred in 2 patients with in situ thrombi.CONCLUSIONS:The frequency of in situ thrombus was extremely high in stroke and migraine groups, while none of the asymptomatic individuals presented with an in situ thrombus. In situ thrombus formation may play a role in patients with PFO-associated stroke or migraines and have therapeutic implications.REGISTRATION:URL: https://www.CLINICALTRIALS:gov; Unique identifier: NCT04686253.

68Ga-FAPI PET/CT for molecular assessment of fibroblast activation in right heart in pulmonary arterial hypertension: a single-center, pilot study.

BACKGROUND:Positron emission tomography (PET) imaging with radiolabeled fibroblasts activation protein inhibitor (FAPI) provides the opportunity to directly visualize fibrosis. This study aimed to investigate the feasibility of 68Ga-FAPI PET imaging in assessing right ventricular (RV) fibrotic remodeling and the relationship between FAPI uptake with parameters of pulmonary hemodynamics and cardiac function in pulmonary arterial hypertension (PAH) patients.METHODS:In this pilot study, sixteen PAH patients were enrolled to participate in cardiac 68Ga-FAPI PET/CT imaging. All patients underwent right heart catheterization and echocardiography for assessment of pulmonary hemodynamics and cardiac function within seven days. Cardiac FAPI uptake was visually assessed and quantified as maximum standardized uptake value (SUVmax).RESULTS:Twelve PAH patients exhibited FAPI uptake in RV free wall and insertion point. The overall activity of FAPI accumulated in the RV free wall (SUVmax: 2.5 ± 1.8, P < 0.001) and insertion point (SUVmax:2.5 ± 1.7, P < 0.001) was significantly upregulated compared to left ventricle (SUVmax:1.5 ± 0.5). Patients with tricuspid annular plane systolic excursion (TAPSE) < 17 mm presented significantly higher uptake than those with TAPSE ≥ 17 mm in both RV free wall (SUVmax: 3.4 ± 1.9 vs 1.7 ± 1.1, P = 0.010) and insertion point (SUVmax: 3.4 ± 1.9 vs 1.6 ± 0.7, P = 0.028), indicating RV uptake of FAPI was associated with RV dysfunction. There was significant positive correlation between cardiac FAPI uptake and total pulmonary resistance and the level of N-terminal pro b-type natriuretic peptide.CONCLUSIONS:68Ga-FAPI PET/CT imaging is feasible to directly visualize fibrotic remodeling of RV in patients with PAH.

Diagnostic value of quantitative myocardial blood flow assessment by NaI(Tl) SPECT in detecting significant stenosis: a prospective, multi-center study.

OBJECTIVES:The aim of this prospective multi-center study was to investigate the diagnostic value of myocardial blood flow (MBF) quantification using NaI(Tl)-based single-photon emission computed tomography (SPECT) for determining coronary artery disease (CAD) defined by quantitative coronary angiography (QCA).BACKGROUND:Absolute quantitation of MBF and myocardial flow reserve (MFR) using SPECT is clinically feasible; however, whether flow quantification using NaI(Tl) SPECT is superior to commonly performed SPECT myocardial perfusion imaging (MPI) in determining CAD has not been evaluated.METHODS:Patients with suspected or known CAD underwent pharmacological stress/rest dynamic SPECT imaging and routine SPECT MPI followed by QCA. Obstructive disease was defined as ≥ 50% reduction in luminal diameter on QCA.RESULTS:One hundred fifty-four patients (462 vessels) were included in the analysis. Obstructive CAD was detected in 76/154 patients (49.4%) and 112/462 vessels (24.2%). Optimal cut-off values were 1.86 mL/min/g for stress MBF and 1.95 for MFR, respectively. Stress MBF and MFR were more sensitive than MPI in both individual patients (stress MBF vs MPI: 81.6% vs 51.3%; MFR vs MPI: 72.4% vs 51.3%) and in coronary vascular regions (stress MBF vs MPI: 78.6% vs 31.3%; MFR vs MPI: 75.9% vs 31.3%; all P < .01). In receiver operating characteristic curve analysis, quantification revealed a significantly greater area under the curve than MPI at the patient (stress MBF vs MPI: 0.761 vs 0.641; MFR vs MPI: 0.770 vs 0.641) and the vessel (stress MBF vs MPI: 0.745 vs 0.613; MFR vs MPI: 0.756 vs 0.613; all P < .05) levels. Integrating quantitative SPECT measures with MPI significantly increased the area under the curve and improved the discriminatory and reclassification capacity.CONCLUSION:Flow quantification using NaI(Tl) SPECT provides superior sensitivity and discriminatory capacity to MPI in detecting significant stenosis. Clinical trial registration NCT03637725.

The value of ventilation/perfusion scanning and CT pulmonary angiography in predicting chronic thromboembolic pulmonary hypertension after acute pulmonary embolism: a one-year follow-up study.

To investigate the value of ventilation/perfusion (V/Q) scanning and CT pulmonary angiography (PA) in predicting CTEPH development after acute pulmonary embolism (APE). This study was performed in APE patients who had undergone both V/Q and CT PA after 3-month anticoagulation. The residual pulmonary obstructions were assessed based on V/Q and CT PA, and then recorded as pulmonary perfusion detect score (PPDs) and CT pulmonary artery obstruction index (PAOI). The predictive performance of PPDs and CT PAOI for CTEPH were determined and risk factors for predicting CTEPH development were identified. A total of 235 patients with initial diagnosis of APE were included in this study. ROC analysis showed that the AUCs of the PPDs and CT PAOI were 0.957 and 0.895, with corresponding cut-off values of 20.50% and 17.50% for predicting CTEPH development. Neither sensitivity nor specificity differed significantly between PPDs and CT PAOI (Sensitivity: 92.00% vs. 80.00%, P = 0.25; Specificity: 88.10% vs. 89.52%, P = 0.69). The univariable and multivariable logistic regression analysis demonstrated that pulmonary arterial hypertension confirmed by echocardiography at initial APE diagnosis (OR: 6.16, 95%CI: 1.31-29.02, P = 0.02), a PPDs of > 20.50% (OR: 22.95, 95%CI: 2.37-222.19, P = 0.007), and a CT PAOI of > 17.50% (OR: 9.98, 95%CI: 2.06-48.49, P = 0.004) were associated with CTEPH development. Both V/Q and CT PA after 3-month anticoagulation for APE showed great performance in predicting CTEPH development, and V/Q scanning has a tendency to be more sensitive but less specific than CT PA. The residual pulmonary embolism detected by V/Q and CT PA was associated with an increased risk of CTEPH development.

Predictive value of SPECT myocardial perfusion imaging in patients with unrevascularized coronary chronic total occlusion.

OBJECTIVE:Data involved the association between myocardial ischaemia and the outcome for unrevascularized coronary chronic total occlusion (CTO) patients were limited. The purpose of this study was to evaluate the predictive value of ischaemia detected by single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for the adverse events in unrevascularized CTO patients. We further explored whether ischaemia generated from CTO vessel can independently predict the outcome.METHODS:Patients with at least one unrevascularized CTO on coronary angiography were enrolled in this study. Exercise stress/rest SPECT MPI was performed in all patients. All patients were then followed by telephone interview and reviewing of medical records.RESULTS:Patients with ischaemia experienced significantly higher rate of adverse events than non-ischaemia patients (40.7% vs 7.1%, P = 0.002). Ischaemia demonstrated on MPI [odds ratio (OR) = 7.656; 95% confidence interval (CI) 1.598-36.677; P = 0.011] was an independent predictor for adverse events. Moreover, CTO-ischaemia (OR = 5.466; 95% CI 1.015-29.420; P = 0.048), non-CTO ischaemia (OR = 29.174; 95% CI 3.245-262.322; P = 0.003), mixed-ischaemia (OR = 7.130, 95% CI 1.257-40.445; P = 0.027) were all independent predictors for outcome.CONCLUSION:Ischaemia demonstrated on MPI, especially CTO-ischaemia were independent predictors for the adverse events. SPECT MPI can aid to identify patients at risk of adverse events, who may benefit from subsequent CTO percutaneous coronary intervention.

First in-human modified atrial septostomy combining radiofrequency ablation and balloon dilation.

OBJECTIVE:Preclinical research suggests that the combined use of radiofrequency ablation and balloon dilation (CURB) could create stable interatrial communications without device implantation. This study examined the first in-human use of CURB for modified atrial septostomy in patients with severe pulmonary arterial hypertension (PAH).METHODS:Between July 2018 and October 2021, CURB was performed in 19 patients with severe PAH (age: 31.5±9.1 years; mean pulmonary artery pressure: 73 mm Hg (IQR: 66-92); pulmonary vascular resistance: 18.7 Wood units (IQR: 17.8-23.3)). Under guidance of intracardiac echocardiography and three-dimensional location system, (1) fossae ovalis was reconstructed and ablated point-by-point with radiofrequency; (2) then graded balloon dilation was performed after transseptal puncture and the optimal size was determined according to the level of arterial oxygen saturation (SatO2); (3) radiofrequency ablation was repeated around the rims of the created fenestration. The interatrial fenestrations were followed-up serially.RESULTS:After CURB, the immediate fenestration size was 4.4 mm (IQR: 4.1-5.1) with intracardiac echocardiography, systolic aortic pressure increased by 10.2±6.9 mm Hg, cardiac index increased by 0.7±0.3 L/min/m2 and room-air resting SatO2 decreased by 6.2±1.9% (p<0.001). One patient experienced increased pericardiac effusion postoperatively; the others had no complications. On follow-up (median: 15.5 months), all interatrial communications were patent with stable size (intraclass correlation coefficient=0.96, 95%CI:0.89 to 0.99). The WHO functional class increased by 1 (IQR: 1-2) (p<0.001) with improvement of exercise capacity (+159.5 m, P<0.001).CONCLUSION:The interatrial communications created with CURB in patients with severe PAH were stable and the mid-term outcomes were satisfactory.TRIAL REGISTRATION NUMBER:NCT03554330.

68Ga-FAPI right heart uptake in a patient with idiopathic pulmonary arterial hypertension.

Sex-specific reference limits of left ventricular ejection fraction and volumes estimated by gated myocardial perfusion imaging for low-risk patients in China: a comparison between three quantitative algorithms.

BACKGROUND:Establishing appropriate reference value limits of left ventricular (LV) functional parameters is fundamental for the assessment of cardiac function. At present, there are no reports aimed at establishing reference limits using gated myocardial perfusion imaging (MPI) in mainland China.METHODS:A total of 175 consecutive patients who were defined as low-risk coronary artery disease patients underwent stress Technetium-99m sestamibi (99mTc-MIBI)-gated myocardial perfusion single-photon emission computed tomography (SPECT) imaging. The LV ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) were obtained by 3 quantitative algorithms: quantitative-gated SPECT, emory cardiac toolbox, and 4-dimensional model SPECT, respectively. The threshold values were obtained using Gaussian distribution or percentiles. The influence of gender, age, and weight on cardiac functional parameters was analyzed by multiple regressions for linear models.RESULTS:For males, the lower reference limits of EF were 52%, 63%, and 58%, respectively; and the upper limits of EDV/ESV were 106/45, 152/55, and 135/55 mL, respectively. For females, the lower reference limits of EF were 58%, 66%, and 65%, respectively; and the upper limits of EDV/ESV were 73/27, 105/31, and 88/29 mL, respectively. Compared to females, males had greater cardiac volume values and lower mean EF values. Bland-Altman plots revealed that the cardiac function parameters calculated by the three quantitative algorithms were in high agreement.CONCLUSIONS:In this study, the reference limits of cardiac parameters calculated by the 3 methods based on single-center data in China were preliminarily established. The threshold values determined by three quantitative algorithms were not interchangeable but were highly correlated.

Ventilation/perfusion imaging predicts response to balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension.

OBJECTS:Although balloon pulmonary angioplasty (BPA) has emerged as an alternative treatment option for chronic thromboembolic pulmonary hypertension (CTEPH), it is followed in some patients by residual PH. We studied the efficacy of BPA on pulmonary blood flow and the predictive value of ventilation/perfusion (V/Q) scanning.METHODS:We retrospectively reviewed the clinical database, which included patients diagnosed with CTEPH who had received BPA. All patients undergone V/Q scanning to quantify the extent of pulmonary perfusion abnormality before and after BPA. Pulmonary hemodynamics were assessed by right heart catheterization, and cardiac function and exercise capacity were evaluated at baseline and post-BPA. A total of 120 CTEPH patients were included for analysis.RESULTS:BPA significantly alleviated mean pulmonary arterial pressure (mPAP: 48.0 ± 12.9 mmHg vs 34.7 ± 10.3 mmHg, P < 0.001) and pulmonary vascular resistance (PVR: 8.8 ± 4.1 Wood units vs 5.2 ± 3.0 Wood units, P < 0.001), and improved cardiac function (N-terminal pro B-type natriuretic peptide: 1628.7 ± 2887.2 pg/mL vs 400.4 ± 669.3 pg/mL, P < 0.001) and exercise capacity (6-minute walking distance: 386 ± 122 m vs 461 ± 86 m, P < 0.001). The extent of pulmonary perfusion abnormality represented by the percentage of perfusion defects (PPDs%) was improved after BPA (50.1 ± 13.6 vs 35.6 ± 14.2, P < 0.001), with the right and inferior lung lobes benefitting the most. PPDs% < 35.5 at baseline and greater restoration of PPDs% after BPA (∆PPDs% > 20.6) were associated with a better response to BPA (PPDs% < 35.5: odds ratio [OR] 10.857, 95% confidence interval [95%CI] 1.393-84.635, P = 0.023; ∆PPDs% > 20.6: OR 1.035, 95% CI 1.002-1.068, P = 0.036).CONCLUSION:BPA significantly restored pulmonary blood flow, predominantly in the right and inferior lobes. V/Q scanning has the potential to predict the therapeutic response to BPA for CTEPH.