Computed Tomography Myocardial Perfusion Research Articles

Fractional flow reserve measurement using dynamic CT perfusion imaging in patients with coronary artery disease

Fractional flow reserve measurement using dynamic CT perfusion imaging in patients with coronary artery disease

Evaluation of pulmonary artery pressure, blood indices, and myocardial microcirculation in rats returning from high altitude to moderate altitude

BackgroundTo investigate changes in pulmonary artery pressure (PAP), blood indices, and myocardial microcirculation in rats returning from high altitude (HA) to moderate altitude (MA).MethodsForty 4-week-old male Sprague-Dawley rats were randomly divided into four groups with ten rats in each group. One group was transported to the MA area (MA-group), and the other three groups were transported to HA (HA-group-A, HA-group-B, and HA-group-C). After 28 weeks of age, the rats from the HA area were transported to the MA area for 0 days, 10 days, and 20 days, respectively. PAP, routine blood tests, and computed tomography myocardial perfusion indices were measured.ResultsCompared with the MA-group, the body weight of HA-groups decreased (p < 0.05), and PAP in HA-group-A and HA-group-B increased (p < 0.05). In the HA groups, PAP initially increased and then decreased. Compared with the MA-group, red blood cells (RBC), hemoglobin (HGB), and hematocrit (HCT) of rats in HA-group-A increased (p < 0.05). Compared with the HA-group-A, RBC, HGB, and HCT of HA-group-B gradually decreased (p < 0.05) while MCV decreased (p < 0.05), and PLT of HA-group-C increased (p < 0.05). Compared with the MA group, blood flow (BF) and blood volume (BV) of the HA-group-A decreased (p < 0.05). Compared with the HA-group-A, TTP increased first and then decreased (p < 0.05), and BF and BV increased gradually (p < 0.05). Pathological results showed that myocardial fiber arrangement was disordered, and cell space widened in the HA group.ConclusionPAP, blood parameters, and myocardial microcirculation in rats returning from high to MA exhibited significant changes.Relevance statementThis study provides an experimental basis for understanding the physiological and pathological mechanisms during the process of deacclimatization to HA and offers new insights for the prevention and treatment of deacclimatization to HA syndrome.Key PointsForty rats were raised in a real plateau environment.Myocardial microcirculation was detected by CT myocardial perfusion imaging.The PAP of the unacclimated rats increased first and then decreased.The myocardial microcirculation of the deacclimated rats showed hyperperfusion changes.Graphical

Prognostic significance of stress dynamic myocardial CT perfusion: comparison with CT-FFR and CT angiography stenosis-the multicenter VALIDITY trial.

This study aimed to investigate the prognostic significance of stress dynamic myocardial CT perfusion imaging (CTP) and determine whether it has incremental advantages over coronary computed tomography angiography (CTA)-derived parameters. This prospective multicenter study included patients with suspected coronary artery disease who had undergone coronary CTA and CTP and were followed for 6 years. The endpoint was time-to-first major adverse cardiovascular event (MACE). MACEs included all-cause mortality, cardiac death, nonfatal myocardial infarction, unstable angina, late revascularization, and heart failure or aggravated angina symptoms requiring hospitalization. The CTP-derived absolute myocardial blood flow (MBF), relative MBF ratio (r-MBF), and the CTA-derived fractional flow reserve (CT-FFR) and stenosis were analyzed. The independent predictors, time-to-event distributions and the incremental prognostic value of CTP over CTA-derived parameters were assessed. A total of 226 patients (66.7 ± 11.3 years, 37.6% women) were enrolled with a median follow-up time of 1233 days. Twenty-one patients (9.29%) experienced MACEs and ten patients (4.4%) experienced hard MACEs. The r-MBF was the only independent predictor for MACEs in both all patients (hazard ratio [HR]: 0.82 (0.69-0.97), p = 0.01) and patients available for CTA stenosis (%) and CT-FFR calculation (HR: 0.72 (0.57-0.91), p = 0.006). The incremental prognostic significance of r-MBF over CT-FFR was confirmed after combining with CTA-derived parameters (concordance index: 0.919 vs. 0.811; p < 0.01). Patients with r-MBF < 0.77 were more likely to experience MACEs and have a lower average survival time (1565 vs. 1790 days; p < 0.01) after stent implantation. CTP-assessed r-MBF was independently correlated with MACEs and provided incremental prognostic significance. Question The prognostic significance of CT perfusion (CTP) lacks sufficient support from clinical research. Findings In this Chinese population, CTP has the strongest prognostic significance, over CT-Fractional Flow Reserve (FFR) and CTA stenosis in predicting major adverse cardiovascular events (MACEs). Clinical relevance Relative myocardial blood flow ratio had the strongest prognostic value and incremental advantages in predicting MACEs beyond CT-FFR and coronary CTA stenosis quantification, as well as advantages in patients with stents, aiding in personalized diagnosis and treatment plans.

Dynamic CT myocardial perfusion combined with coronary CT angiography for detecting hemodynamical significance of coronary artery stenosis: a comparative study

This study aimed to evaluate the diagnostic performance of combined dynamic stress CT myocardial perfusion imaging (CTP) and coronary CT angiography (CTA) alongside CT-derived fractional flow reserve (CT-FFR) in detecting hemodynamically significant coronary artery disease (CAD). A total of 33 patients (86 vessels) who underwent coronary CTA, dynamic stress CTP, and coronary angiography were included. Vessels exhibiting 30–90% stenosis were subjected to FFR analysis based on coronary angiography (Angio-FFR). Hemodynamic significance, determined by Angio-FFR ≤ 0.80, and imaging findings were evaluated. The evaluation involved a comparison between the combined use of coronary CTA, CTP and CT-FFR, versus the sole use of coronary CTA. Out of 86 coronary vessels, 17 (19.8%) exhibited hemodynamically significant stenosis. The sensitivity, specificity, and accuracy of coronary CTA for detecting ischemia were 94.12%, 34.78%, and 46.51%, respectively. Adding CTP to CTA improved specificity to 88.41%, and accuracy to 87.21%, respectively. The area under the curve (AUC) for the discrimination of functional significant stenosis was 0.798 when using CTA alone, and for CTA plus CTP, it reached 0.910. Furthermore, the combination of CTA, CTP and CT-FFR, showed accuracy of 88.37%, sensitivity of 88.24% and specificity of 88.41% with the AUC of 0.946. The integration of dynamic CTP with CTA significantly enhances the diagnostic accuracy for identifying patients with hemodynamically significant CAD, compared to the use of CTA alone. This study underscores the value of combining CTP, CT-FFR, and CTA in improving diagnostic precision for CAD. The combination of CTP, CT-FFR and CTA offers a multifaceted assessment for patients with CAD by simultaneously providing anatomical detail, functional analysis, and physiological quantification, which facilitating rapid, accurate, and optimal clinical decision-making and significantly enhances patient management.

Integrating myocardial CT perfusion with coronary CT angiography improves risk stratification in patients with dialysis-dependent end-stage renal disease.

Risk stratification for incidence of major adverse cardiovascular events (MACE) in patients with dialysis-dependent end-stage renal disease (dd-ESRD) is challenging. Moreover, the usefulness of coronary CT angiography (CCTA) is often limited because of high calcification. This study aimed to investigate the prognostic value of comprehensive cardiac CT in patients with dd-ESRD for predicting MACE. This retrospective analysis included 92 patients with dd-ESRD who underwent comprehensive cardiac CT.Obstructive coronary artery disease (CAD) was defined by CCTA with > 50% stenosis. Global myocardial blood flow (MBF) and summed stress score (SSS) were obtained through dynamic CTP. Cox regression analysis was used to assess correlation with MACE. Kaplan-Meier curves were used to estimate cumulative event rates, and the global Chi-square test was used to assess the incremental value of dynamic CTP over CCTA. During a median follow-up of 2.3years, 43 patients experienced MACE. Univariate analysis revealed that presence of obstructive CAD, higher SSS, and lower global MBF were significantly associated with increased risk of MACE. In multivariable analysis, lower global MBF and presence of obstructive CAD were independently associated with MACE (p = 0.02, and p = 0.04, respectively). CCTA and dynamic CTP combination had incremental value over CCTA alone for predicting MACE, respectively (global Chi-square score, 19.3 and 11.7, respectively). Presence of obstructive CAD on CCTA and lower global MBF on dynamic CTP are independently associated with increased risk of MACE in patients with dd-ESRD. The addition of dynamic CTP to CCTA may improve risk stratification in this population.

Quantification and Visualization of CT Myocardial Perfusion Imaging to Detect Ischemia-Causing Coronary Arteries.

Coronary computed tomography angiography (cCTA) has poor specificity to identify coronary stenosis that limit blood flow to the myocardial tissue. Integration of dynamic CT myocardial perfusion imaging (CT-MPI) can potentially improve the diagnostic accuracy. We propose a method that integrates cCTA and CT-MPI to identify culprit coronary lesions that limit blood flow to the myocardium. Coronary arteries and left ventricle surfaces were segmented from cCTA and registered to CT-MPI. Myocardial blood flow (MBF) was derived from CT-MPI. A ray-casting approach was developed to project volumetric MBF onto the left ventricle surface. MBF volume were divided into coronary-specific territories based on proximity to the nearest coronary artery. MBF and normalized MBF were computed for the myocardium and each of the coronary artery. Projection of MBF onto cCTA allowed for direct visualization of perfusion defects. Normalized MBF had higher correlation with ischemic myocardial territory compared to MBF (MBF: R2=0.81 and Index MBF: R2=0.90). There were 18 vessels that showed angiographic disease (stenosis >50%); however, normalized MBF demonstrated only 5 coronary territories to be ischemic. These findings demonstrate that cCTA and CT-MPI can be integrated to visualize myocardial defects and detect culprit coronary arteries responsible for perfusion defects. These methods can allow for non-invasive detection of ischemia-causing coronary lesions and ultimately help guide clinicians to deliver more targeted coronary interventions.

Different degrees of summed difference perfusion score in women: influence on the prognostic variables associated with cardiac events.

Evaluating the predictive models (PM) for a major adverse cardiac event (MACE) only in women with abnormal summed difference score (SDS ≥ 1), borderline myocardial ischemia (borderline-MIsch: SDS = 1), MIsch (SDS ≥ 2), mild-MIsch (SDS = 2-4), and moderate-severe MIsch (ms-MIsch: SDS ≥ 5). Between January 2000 and January 2018, of 25 943 consecutive patients who underwent gated single-photon emission computed tomography myocardial perfusion imaging (gSPECT-MPI) for coronary risk stratification; 717 women (age 68.37 ± 3.4 years) with an abnormal SDS ≥ 1 were included. During the follow-up (mean 4 ± 2.9 years) post-gSPECT-MPI, MACE (unstable angina, nonfatal myocardial infarction, coronary revascularization, cardiac death) was assessed. In the global women cohort with abnormal SDS (n = 717), the PM was angina [hazard ratio (HR): 1.65, P = 0.016], diabetes (HR: 1.72, P = 0.004), beta-blockers (HR: 1.61, P = 0.009), pharmacological stress (HR: 1.74, P = 0.007), ↓ segment (ST) mm ≥ 1 (HR: 1.54, P = 0.039), and moderate-to-severe abnormal summed stress score (ms-SSS) (HR: 2.92, P = 0.001). In borderline-MIsch group (n = 208), the PM was previous myocardial infarction (HR: 3.8, P = 0.001), nitrates (HR: 2.13, P = 0.047), pharmacological stress (HR: 4.81, P < 0.001), and ↓ST mm ≥ 1 (HR: 3.07, P = 0.014). In MIsch group (n = 509), the PM model was ms-SSS (HR: 2.25, P = 0.001), diabetes (HR: 1.73, P = 0.011), angina (HR: 1.68, P = 0.029), beta-blockers (HR: 1.59, P = 0.026), and ms-MIsch (HR: 1.62, P = 0.044). In mild-MIsch group (n = 399), the PM was ms-SSS (HR: 2.55, P = 0.003), diabetes (HR: 2.17, P = 0.004), angina (HR: 1.89, P = 0.037), and beta-blockers (HR: 2.01, P = 0.011). In ms-MIsch group (n = 110), the predictive variable for MACE was ms-SSS (HR: 2.27, P = 0.016). The ms-SSS significantly increases the prognostic value of the ms-MIsch (P = 0.001). Women with different degrees of abnormal SDS have different PMs of MACE. The ms-SSS stands out as the most significant predictive variable.

Association between an Early Revascularization Strategy and Major Cardiac Events Based on Left Ventricular Dyssynchrony in Patients at Intermediate Risk of Major Cardiac Events Using the J-ACCESS Risk Model.

Objective This retrospective study aimed to investigate the association between therapeutic strategies and the development of major cardiac events (MCEs) in intermediate-risk patients by using the the Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT (JACCESS) risk model in combination with the stress phase bandwidth (SPBW), an index of left ventricular dyssynchrony. Methods Patients were followed-up for three years to confirm their prognosis. Based on the estimated propensity scores, the patients who underwent revascularization within the first 60 days after SPECT and those who did not were matched 1:1 (n=367 per group). The composite endpoint was the occurrence of MCEs, consisting of cardiac death, non-fatal myocardial infarction, and severe heart failure. SPBW was calculated by a phase analysis using the Heart Risk View-F software program, and the MCE rate was compared between the two groups by applying the normal value of SPBW (38°). Patients The study included 2,053 patients with either known or suspected coronary artery disease who underwent electrocardiogram-gated single-photon emission computed tomography myocardial perfusion imaging and were at intermediate risk of MCE according to the J-ACCESS risk model. Results During follow-up, 54 of the 734 patients (7.4%) experienced MCEs. The overall incidence of MCE in intermediate-risk patients was not significantly different between the two groups. However, the incidence of MCE in patients with an abnormal SPBW was significantly lower in those who underwent early revascularization (4.8% vs. 11.9%, p=0.0407). Conclusion The combination of the J-ACCESS risk model and the SPBW is thus considered to be an optimal treatment strategy for patients at intermediate risk of MCE, and early revascularization may lead to an improved prognosis in intermediate-risk patients with an abnormal SPBW.

Real-world evidence study on the impact of SPECT MPI, PET MPI, cCTA and stress echocardiography on downstream healthcare utilisation in patients with coronary artery disease in the US.

Coronary artery disease (CAD) is associated with a large clinical and economic burden. However, consensus on the optimal approach to CAD diagnosis is lacking. This study sought to compare downstream healthcare resource utilisation following different cardiac imaging modalities, to inform test selection for CAD diagnosis. Claims and electronic health records data from the Decision Resources Group Real-World Evidence US Data Repository were analysed for 2.5 million US patients who underwent single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI), positron emission tomography myocardial perfusion imaging (PET MPI), coronary computed tomography angiography (cCTA), or stress echocardiography between January 2016 and March 2018. Patients were stratified into nine cohorts based on suspected or existing CAD diagnosis, pre-test risk, and prior events or interventions. Downstream healthcare utilisation, including additional diagnostic imaging, coronary angiography, and cardiac-related health system encounters, was compared by cohort and index imaging modality. Among patients with suspected CAD diagnosed within 3 months of the index test, PET MPI was associated with lower downstream utilisation; 25-37% of patients who underwent PET MPI required additional downstream healthcare resources compared with 40-49% of patients who received SPECT MPI, 35-41% of patients who underwent cCTA, and 44-47% of patients who received stress echocardiography. Patients who underwent PET MPI experienced fewer acute cardiac events (5.3-9.4%) and generally had lower rates of healthcare encounters (0.8-4.1%) and invasive coronary angiography (ICA, 15.4-24.2%) than those who underwent other modalities. SPECT MPI was associated with more downstream ICA (31.3-38.2%) and a higher rate of cardiac events (9.5-13.2%) compared with PET MPI (5.3-9.4%) and cCTA (6.9-9.9%). Across all cohorts, additional diagnostic imaging was 1.6 to 4.7 times more frequent with cCTA compared with PET MPI. Choice of imaging modality for CAD diagnosis impacts downstream healthcare utilisation. PET MPI was associated with lower utilisation across multiple metrics compared with other imaging modalities studied.

The prognostic utility of heart rate and blood pressure response to regadenoson stress

BackgroundAlthough heart rate response (HRR) to regadenoson stress has been shown to be a strong predictor of outcome, it has not been investigated in a large all-comers cohort. The prognostic utility of systolic blood pressure response (SBPR) has not been investigated in comparison with HRR. Methods and resultsIn a retrospective cohort of 10,227 patients undergoing regadenoson stress single-photon emission computed tomography myocardial perfusion imaging (MPI), HRR, and SBPR were calculated as 100×(peak hyperemia value–baseline value)/baseline value. During 35±21 months follow-up, 921 (8.8%) deaths were observed. The median HRR was 35% (interquartile range [IQR], 21% to 51%). The median SBPR was −9% (IQR, −17% to −2%). HRR and SBPR were independently associated with all-cause mortality with adjusted hazard ratio [HR] of .980 per 1% increment in HRR (CI, .977-.984) and .994 per 1% increment in SBPR (CI, .988-.999). Mortality rates increased with decreasing HRR quartile and SBPR tertile. HRR provided incremental prognostic value for all-cause mortality beyond clinical and imaging parameters (area under the curve [AUC] increase, .03; P<.001) and SBPR data (AUC increase, .11; P<0001). SBPR did not provide significant incremental prognostic value beyond clinical and imaging parameters or HRR data. We derived and validated HRR of <20% as a cut-off that can improve risk stratification beyond clinical and MPI findings. ConclusionAmong patients undergoing stress MPI, impaired HRR to regadenoson provided independent and incremental prognostic value for all-cause mortality beyond clinical, imaging, and SBPR data. SBPR positively correlates with HRR, but it does not provide incremental prognostic utility. HRR, but not SBPR, should be routinely reported and considered in assessing patients' overall risk. An abnormal HRR threshold of <20% can improve risk stratification.

Prognostic value of stress CMR and SPECT-MPI in patients undergoing intermediate-to-high-risk non-cardiac surgery

PurposeThe objective of this study was to investigate the role of myocardial perfusion imaging (MPI) stress tests using stress cardiac magnetic resonance (sCMR) and single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) in non-cardiac surgery (NCS) pre-operatory management.Materials and methodsThis monocentric retrospective study enrolled patients with coronary artery disease or a minimum of two cardiovascular risk factors undergoing intermediate-to-high-risk non-cardiac surgeries. The primary composite endpoint comprised cardiac death, cardiogenic shock, acute coronary syndromes (ACS), and cardiogenic pulmonary edema occurring within 30 days after surgery, while the secondary endpoint was ACS.ResultsA total of 1590 patients were enrolled; among them, 669 underwent a MPI stress test strategy (sCMR: 287, SPECT-MPI: 382). The incidence of 30-day cardiac events was lower in the stress-tested group compared to the non-stress-tested group (1.2% vs. 3.4%; p 0.006). Adopting a stress test strategy showed a significant reduction in the risk of the composite endpoint (OR: 0.33, 95% CI: 0.15–0.76, p 0.009) and ACS (OR: 0.41, 95% CI: 0.17–0.98, p 0.046) at multivariable analysis, with similar cardiac events rate between stress CMR and SPECT (1.1% vs. 1.3%, p 0.756). Stress CMR showed a greater accuracy to predict coronary artery revascularizations (sCMR c-statistic: 0.95, ischemic cut-point: 5.5%; SPECT c-statistic: 0.85, ischemic cut-point: 7.5%).ConclusionStress test strategy is related to a lower occurrence of cardiac events in high-risk patients scheduled for intermediate-to-high-risk non-cardiac surgeries. Both sCMR and SPECT-MPI comparably reduce the likelihood of cardiac complications, albeit sCMR offers greater accuracy in predicting coronary artery revascularization.

Value of Ischemia and Coronary Anatomy in Prognosis and Guiding Revascularization Among Patients With Stable Ischemic Heart Disease.

The value of physiological ischemia versus anatomic severity of disease for prognosis and management of patients with stable coronary artery disease (CAD) is widely debated. A total of 1764 patients who had rest-stress cadmium-zinc-telluride single-photon emission computed tomography myocardial perfusion imaging and angiography (invasive or computed tomography) were prospectively enrolled and followed for cardiac death/nonfatal myocardial infarction. The CAD prognostic index (CADPI) was used to quantify the extent and severity of angiographic disease. Prognostic value was assessed using Cox models, adjusted for pretest risk, known CAD, stressor, left ventricular ejection fraction, %ischemia and infarct, CADPI, and early (90-day) revascularization. Incremental prognostic value was evaluated using net reclassification index. The mean age was 69.7±9.5 years, 24.4% were women, and 29.3% had known CAD. Significant ischemia (>10%) was present in 28.4%. Nonobstructive, single, and multivessel disease was present in 256 (14.5%), 772 (43.8%), and 736 (41.7%), respectively. Early revascularization occurred in 579 (32.8%). Cardiac death/myocardial infarction occurred in 148 (8.4%) over a 4.6-year median follow-up. Both %ischemia and CADPI provided independent and incremental prognostic value over pretest clinical risk (P<0.001). In a model containing both ischemia and anatomy, ischemia was prognostic (hazard ratio per 5% ↑, 1.35 [95% CI, 1.11-1.63]; P=0.002) but CADPI was not (hazard ratio per 10-unit ↑, 1.09 [95% CI, 0.99-1.20]; P=0.07). Early revascularization modified the risk associated with %ischemia (interaction P=0.003) but not with CADPI (interaction P=0.6). %Ischemia and single-photon emission computed tomography variables added incremental prognostic value over clinical risk and CADPI (net reclassification index, 20.3% [95% CI, 9%-32%]; P<0.05); however, CADPI was not incrementally prognostic beyond pretest risk, %ischemia, and single-photon emission computed tomography variables (net reclassification index, 3.1% [95% CI, -5% to 15%]; P=0.21). Ischemic burden provides independent and incremental prognostic value beyond CAD anatomy and identifies patients who benefit from early revascularization. The anatomic extent of disease has independent prognostic value over clinical risk factors but offers limited incremental benefit for prognosis and guiding revascularization beyond physiological severity (ischemia).

Two-dimensional speckle tracking echocardiography and stress computed tomography myocardial perfusion: potential for early imaging of asymptomatic patients with myocardial bridges

Aim. To evaluate the effectiveness of left ventricular (LV) peak global longitudinal strain and potential of computed tomography myocardial perfusion (CT perfusion) for the early diagnosis of asymptomatic patients with myocardial bridges (MBs).Material and methods. Forty patients were examined (20 with asymptomatic MBs in the area of the left anterior descending (LAD) artery and 20 without MBs) at the S. M. Kirov Military Medical Academy in the period from 2021 to 2023. The patients were divided into 2 equal groups consisting of 20 people (10 with MBs — the main group; 10 without MBs — the comparison group), one of which underwent speckle tracking echocardiography (STE), and the other — stress CT perfusion performed (adenosine triphosphate 160 mg/kg). The results were assessed in accordance with the 17-segment classification of LV proposed by the American Heart Association (2002).Results. When performing STE, 5 (50%) patients with MBs showed a decrease in LV local strain in the segments, the blood supply of which comes from the LAD artery and its branches, while in the comparison group — 1 (10%) (x2=5; p=0,025). When assessing the global longitudinal peak strain (GLPS), a significant difference was revealed among the study groups, amounting to -20,9±1,5% in patients with MBs and -22,1±0,9% in those without MBs (p=0,04). Using ROC analysis, the effectiveness of GLPS in prediction of asymptomatic MBs was calculated as follows: AUC=0,93 (95% confidence interval: 0,819-1,0; p=0,001), the cut-off point — -20,55% (sensitivity 80%, specificity 100%). According to CT perfusion data, impaired myocardial blood supply in the group of asymptomatic patients with MBs was noted in 6 (60%) cases, and in the comparison group — 2 (20%) (x2=9,8; p=0,002).Conclusion. Imaging of initial LV changes according to two-dimensional STE and detection of coronary circulatory disorders according to CT myocardial perfusion in asymptomatic patients with MBs makes it possible to timely suspect intramyocardial course of the coronary artery, as well as to consider further management tactics and carry out early prevention of possible cardiovascular events.

Reproducibility of a single-volume dynamic CT myocardial blood flow measurement technique: validation in a swine model

BackgroundWe prospectively assessed the reproducibility of a novel low-dose single-volume dynamic computed tomography (CT) myocardial blood flow measurement technique.MethodsThirty-four pairs of measurements were made under rest and stress conditions in 13 swine (54.3 ± 12.3 kg). One or two acquisition pairs were acquired in each animal with a 10-min delay between each pair. Contrast (370 mgI/mL; 0.5 mL/kg) and a diluted contrast/saline chaser (0.5 mL/kg; 30:70 contrast/saline) were injected peripherally at 5 mL/s, followed by bolus tracking and acquisition of a single volume scan (100 kVp; 200 mA) with a 320-slice CT scanner. Bolus tracking and single volume scan data were used to derive perfusion in mL/min/g using a first-pass analysis model; the coronary perfusion territories of the left anterior descending (LAD), left circumflex (LCx), and right coronary artery (RCA) were automatically assigned using a previously validated minimum-cost path technique. The reproducibility of CT myocardial perfusion measurement within the LAD, LCx, RCA, and the whole myocardium was assessed via regression analysis. The average CT dose index (CTDI) of perfusion measurement was recorded.ResultsThe repeated first (Pmyo1) and second (Pmyo2) single-volume CT perfusion measurements were related by Pmyo2 = 1.01Pmyo1 − 0.03(ρ = 0.96; RMSE = 0.08 mL/min/g; RMSE = 0.07 mL/min/g) for the whole myocardium, and by Preg2 = 0.86Preg1 + 0.13(ρ = 0.87; RMSE = 0.31 mL/min/g; RMSE = 0.29 mL/min/g) for the LAD, LCx, and RCA perfusion territories. The average CTDI of the single-volume CT perfusion measurement was 10.5 mGy.ConclusionThe single-volume CT blood flow measurement technique provides reproducible low-dose myocardial perfusion measurement using only bolus tracking data and a single whole-heart volume scan.Relevance statementThe single-volume CT blood flow measurement technique is a noninvasive tool that reproducibly measures myocardial perfusion and provides coronary CT angiograms, allowing for simultaneous anatomic-physiologic assessment of myocardial ischemia.Key PointsA low-dose single-volume dynamic CT myocardial blood flow measurement technique is reproducible.Motion misregistration artifacts are eliminated using a single-volume CT perfusion technique.This technique enables combined anatomic-physiologic assessment of coronary artery disease.Graphical

CT Myocardial Perfusion and CT-FFR versus Invasive FFR for Hemodynamic Relevance of Coronary Artery Disease.

Background CT-derived fractional flow reserve (CT-FFR) and dynamic CT myocardial perfusion imaging enhance the specificity of coronary CT angiography (CCTA) for ruling out coronary artery disease (CAD). However, evidence on comparative diagnostic value remains scarce. Purpose To compare the diagnostic accuracy of CCTA plus CT-FFR, CCTA plus CT perfusion, and sequential CCTA plus CT-FFR and CT perfusion for detecting hemodynamically relevant CAD with that of invasive angiography. Materials and Methods This secondary analysis of a prospective study included patients with chest pain referred for invasive coronary angiography at nine centers from July 2016 to September 2019. CCTA and CT perfusion were performed with third-generation dual-source CT scanners. CT-FFR was assessed on-site. Independent core laboratories analyzed CCTA alone, CCTA plus CT perfusion, CCTA plus CT-FFR, and a sequential approach involving CCTA plus CT-FFR and CT perfusion for the presence of hemodynamically relevant stenosis. Invasive coronary angiography with invasive fractional flow reserve was the reference standard. Diagnostic accuracy metrics and the area under the receiver operating characteristic curve (AUC) were compared with the Sign test and DeLong test. Results Of the 105 participants (mean age, 64 years ± 8 [SD]; 68 male), 49 (47%) had hemodynamically relevant stenoses at invasive coronary angiography. CCTA plus CT-FFR and CCTA plus CT perfusion showed no evidence of a difference for participant-based sensitivities (90% vs 90%, P > .99), specificities (77% vs 79%, P > .99) and vessel-based AUCs (0.84 [95% CI: 0.77, 0.91] vs 0.83 [95% CI: 0.75, 0.91], P = .90). Both had higher participant-based specificity than CCTA alone (54%, both P < .001) without evidence of a difference in sensitivity between CCTA (94%) and CCTA plus CT perfusion (P = .50) or CCTA plus CT-FFR (P = .63). The sequential approach combining CCTA plus CT-FFR with CT perfusion achieved higher participant-based specificity than CCTA plus CT-FFR (88% vs 77%, P = .03) without evidence of a difference in participant-based sensitivity (88% vs 90%, P > .99) and vessel-based AUC (0.85 [95% CI: 0.77, 0.93], P = .78). Compared with CCTA plus CT perfusion, the sequential approach showed no evidence of a difference in participant-based sensitivity (P > .99), specificity (P = .06), or vessel-based AUC (P = .54). Conclusion There was no evidence of a difference in diagnostic accuracy between CCTA plus CT-FFR and CCTA plus CT perfusion for detecting hemodynamically relevant CAD. A sequential approach combining CCTA plus CT-FFR with CT perfusion led to improved participant-based specificity with no evidence of a difference in sensitivity compared with CCTA plus CT-FFR. ClinicalTrials.gov registration no.: NCT02810795 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Sinitsyn in this issue.

Usefulness of Phase Analysis With Single Photon Emission Computed Tomography Myocardial Perfusion Imaging To Predict the Prognosis of Cardiovascular Events

Usefulness of Phase Analysis With Single Photon Emission Computed Tomography Myocardial Perfusion Imaging To Predict the Prognosis of Cardiovascular Events

The impact of lipoprotein(a) level on cardiac pathologies in diabetes: a cardiac CT study.

We aimed to explore the imaging profile of coronary atherosclerosis, perivascular inflammation, myocardial perfusion, and interstitial fibrosis in diabetes stratified by lipoprotein(a) [Lp(a)] levels. In this prospective study, we enrolled diabetic patients who had undergone computed tomography (CT) angiography, stress CT-myocardial perfusion imaging, and late iodine enhancement in 20 months. Then, we categorized them into elevated and normal groups based on an Lp(a) cutoff level of 30 mg/dL. All imaging data, including coronary atherosclerosis parameters, pericoronary adipose tissue (PCAT) density, stress myocardial blood flow (MBF), and extracellular volume (ECV), were collected for further analysis. In total, 207 participants (mean age: 59.1 ± 12.0 years, 111 males) were included in this study. Patients with elevated Lp(a) level had more pronounced percent atheroma volume (2.55% (1.01-9.01%) versus 1.30% (0-4.95%), p = 0.010), and demonstrated a higher incidence of positive remodeling, spotty calcification, and high-risk plaque (HRP) than those with normal Lp(a) levels (75.6% versus 54.8%, p = 0.015; 26.8% versus 9.6%, p = 0.003; 51.2% versus 30.1%, p = 0.011, respectively). Results of the multivariate analysis revealed that after adjusting for all clinical characteristics, elevated Lp(a) levels were an independent parameter associated with HRP (odds ratio = 2.608; 95% confidence interval: 1.254-5.423, p = 0.010). However, no significant difference was found between the two groups in terms of PCAT density, stress MBF, and ECV. Elevated Lp(a) levels are associated with extensive coronary atherosclerosis and HRP development. However, they are not related to perivascular inflammation, decreased myocardial perfusion, and interstitial fibrosis in diabetes. Elevated lipoprotein(a) levels are associated with extensive coronary atherosclerosis and a high incidence of HRPs. However, they are not related to perivascular inflammation, decreased myocardial perfusion, and interstitial fibrosis in diabetes. Diabetes is a known risk factor that accelerates cardiovascular disease progression. Diabetics with elevated lipoprotein(a) (Lp(a)) levels had a higher percent atheroma volume and positive remodeling, spotty calcification, and HRPs. Patients with diabetes should be screened for elevated Lp(a) using CCTA for comprehensive evaluation of atherosclerotic characteristics.

Comparative effectiveness of positron emission tomography and single-photon emission computed tomography myocardial perfusion imaging for predicting risk in patients with cardiometabolic disease

BackgroundThe epidemiology of coronary artery disease (CAD) has shifted, with increasing prevalence of cardiometabolic disease and decreasing findings of obstructive CAD on myocardial perfusion imaging (MPI). Coronary microvascular dysfunction (CMD), defined as impaired myocardial flow reserve (MFR) by positron emission tomography (PET), has emerged as a key mediator of risk. We aimed to assess whether PET MFR provides additive value for risk stratification of cardiometabolic disease patients compared with single-photon emission computed tomography (SPECT) MPI. MethodsWe retrospectively followed patients referred for PET, exercise SPECT, or pharmacologic SPECT MPI with cardiometabolic disease (obesity, diabetes, or chronic kidney disease) and without known CAD. We compared rates and hazards of composite major adverse cardiovascular events (MACEs) (annualized cardiac mortality or acute myocardial infarction) among propensity-matched PET and SPECT patients using Poisson and Cox regression. Normal SPECT was defined as a total perfusion deficit (TPD) of <5%, reflecting the absence of obstructive CAD. Normal PET was defined as a TPD of <5% plus an MFR of ≥2.0. ResultsAmong 21,544 patients referred from 2006 to 2020, cardiometabolic disease was highly prevalent (PET: 2308 [67%], SPECT: 9984 [55%]) and higher among patients referred to PET (P < 0.001). Obstructive CAD findings (TPD > 5%) were uncommon (PET: 21% and SPECT: 11%). Conversely, impaired MFR on PET (<2.0) was common (62%). In a propensity-matched analysis over a median 6.4-year follow-up, normal PET identified low-risk (0.9%/year MACE) patients, and abnormal PET identified high-risk (4.2%/year MACE) patients with cardiometabolic disease; conversely, those with normal pharmacologic SPECT remained moderate-risk (1.6%/year, P < 0.001 compared to normal PET). ConclusionsCardiometabolic disease is common among patients referred for MPI and is associated with a heterogenous level of risk. Compared with pharmacologic SPECT, PET with MFR can detect nonobstructive CAD including CMD and can more accurately discriminate low-risk from higher-risk individuals.

Evaluating the Predictive Value of a Cardiac Perfusion Scan for Cardiac Events in Chronic Kidney Disease

Background: Cardiovascular diseases are among the leading causes of morbidity and mortality in chronic kidney disease (CKD) patients. Therefore, predicting cardiac events in CKD patients is essential. Objectives: The present study aims to evaluate the predictive value of single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) in patients with different stages of CKD. Methods: Consecutive CKD patients with an estimated glomerular filtration rate (eGFR

EE116 Budget Impact Model Framework of Positron Emission Tomography Compared to Single Photon Emission Computed Tomography Myocardial Perfusion Imaging for Coronary Artery Disease Diagnosis

EE116 Budget Impact Model Framework of Positron Emission Tomography Compared to Single Photon Emission Computed Tomography Myocardial Perfusion Imaging for Coronary Artery Disease Diagnosis