Regional CZT myocardial perfusion reserve for the detection of territories with simultaneously impaired CFR and IMR in patients without obstructive coronary artery disease: a pilot study.

OBJECTIVES: To assess the diagnostic performances of CZT myocardial perfusion reserve (MPR) for the detection of territories with simultaneous impaired coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) in patients without obstructive coronary artery disease. METHODS: Patients were prospectively included before being referred for coronary angiography. All patients underwent CZT MPR before invasive coronary angiography (ICA) and coronary physiology assessment. Rest and dipyridamole-induced stress myocardial blood flow (MBF) and MPR were quantified using 99mTc-SestaMIBI and a CZT camera. Fractional flow reserve (FFR), Thermodilution CFR, and IMR were assessed during ICA. RESULTS: Between December 2016 and July 2019, 36 patients were included. 25/36 patients presented no obstructive coronary artery disease. A complete functional assessment was performed in 32 arteries. No territory presented a significant ischemia on CZT myocardial perfusion imaging. A moderate yet significant correlation was observed between regional CZT MPR and CFR (r = 0.4, P = .03). Sensitivity, specificity, positive and negative predictive value, and accuracy of regional CZT MPR versus the composite invasive criterion (impaired CFR and IMR) were 87 [47% to 99%], 92% [73% to 99%], 78% [47% to 93%], 96% [78% to 99%], and 91% [75% to 98%], respectively. All territories with a regional CZT MPR ≤ 1.8 showed a CFR < 2. Regional CZT MPR values were significantly higher in arteries with CFR ≥ 2 and IMR < 25 (negative composite criterion, n = 14) than in those with CFR < 2 and IMR ≥ 25 (2.6 [2.1 to 3.6] versus 1.6 [1.2 to 1.8]), P < .01). CONCLUSION: Regional CZT MPR presented excellent diagnostic performances for the detection of territories with simultaneously impaired CFR and IMR reflecting a very high cardiovascular risk in patients without obstructive coronary artery disease.

Noninvasive assessment of coronary microvascular dysfunction using SPECT myocardial perfusion imaging and myocardial perfusion entropy quantification in a rodent model of type 2 diabetes.

PURPOSE: Coronary microvascular dysfunction (CMVD) plays a major role in the occurrence of cardiovascular events (CVE). We recently suggested the clinical potential of myocardial perfusion entropy (MPE) quantification from SPECT myocardial perfusion images (MPI) for the prognosis of CVE occurrence. We hypothesized that the quantification of MPE from SPECT MPI would allow the assessment of CMVD-related MPE variations in a preclinical model of type 2 diabetes (T2D) including treatment with the anti-diabetic incretin liraglutide (LIR). METHODS: Optimal conditions for the preclinical quantification of MPE using 201Tl SPECT MPI were determined in rats with a T2D-like condition induced by a high-fat diet and streptozotocin injection (feasibility study, n = 43). Using such conditions, echocardiography and post-mortem LV capillary density evaluation were then used in order to assess the effect of LIR and the ability of MPE to assess CMVD (therapeutic study, n = 39). RESULTS: The feasibility study identified dobutamine stress and acute NO synthase and cyclooxygenase inhibition as optimal conditions for the quantification of MPE, with significant increases in MPE being observed in T2D animals (P < 0.01 vs controls). In the therapeutic study, T2D rats were hyperglycemic (5.5 ± 0.5 vs 1.1 ± 0.3 g/L for controls, P < 0.001) and had a significantly lower left ventricular ejection fraction (LVEF) (65 ± 4% vs 74 ± 9%, P < 0.01) and LV capillary density (2400 ± 300 vs 2800 ± 600 mm-3, P < 0.05). LIR partially restored glycemia (3.9 ± 0.6 g/L, P < 0.05 vs controls and T2D), totally prevented LVEF impairment (72 ± 7%, P = NS vs CTL), with no significant effect on capillary density. MPE was significantly increased in T2D rats (7.6 ± 0.5 vs 7.1 ± 0.5, P < 0.05), with no significant improvement in T2D-LIR rats (7.4 ± 0.4, P = NS vs controls and T2D). CONCLUSION: MPE quantification allowed the preclinical noninvasive assessment of CMVD. Both MPE and capillary density quantification suggested that LIR did not improve T2D-induced CMVD. The relevance of MPE for CMVD assessment warrants further clinical investigation.

Comparison of Cadmium Zinc Telluride ECG-gated SPECT equilibrium radionuclide angiocardiography to magnetic resonance imaging to measure right ventricular volumes and ejection fraction in patients with cardiomyopathy.

AIMS: The objective of this study was to determine the accuracy of right ventricular function (RVF) assessed by Cadmium Zinc Telluride ECG-gated SPECT equilibrium radionuclide angiocardiography (CZT-ERNA). METHODS AND RESULTS: Twenty-one consecutive patients with cardiomyopathy (aged 54 ± 19 years; 62% male) were included. RV ejection fraction (EF) and volumes were analyzed by CZT-ERNA and compared with values obtained by cardiac magnetic resonance imaging (CMR). Mean values were not different between CZT-ERNA and MRI for RVEF (48.1 ± 10.4% vs 50.8 ± 10.0%; P = .23). Significant correlations (P < .0001) were observed between CZT-ERNA and MRI for RVEF, RV end-diastolic volume, and end-systolic volume (r = 0.81, r = 0.93, and r = 0.96, respectively). Bland-Altman analysis showed a mean difference (bias) between CZT-ERNA and MRI for RVEF of -2.69% (95% CI - 5.35 to - 0.42) with good agreement between the 2 techniques (limits of agreement, -14.3 to 8.99). Intraobserver and interobserver reproducibility of RVF measured by CZT-ERNA was high. CONCLUSION: CZT-ERNA provides accurate, reproducible assessment of RVF and appears as a good alternative to cardiac magnetic resonance for the evaluation of the magnitude of RVF in patients with cardiomyopathy.

Prognostic value of SPECT myocardial perfusion entropy in high-risk type 2 diabetic patients.

PURPOSE: Risk stratification of patients with type 2 diabetes mellitus (T2D) remains suboptimal. We hypothesized that myocardial perfusion entropy (MPE) quantified from SPECT myocardial perfusion images may provide incremental prognostic value in T2D patients independently from myocardial ischemia. METHODS: T2D patients with very high and high cardiovascular risk were prospectively included (n = 166, 65 ± 12 years). Stress perfusion defect was quantified by visual evaluation of SPECT MPI. SPECT MPI was also used for the quantification of rest and stress MPE. The primary end point was major adverse cardiac events (MACEs) defined as cardiac death, myocardial infarction (MI), and myocardial revascularization > 3 months after SPECT. RESULTS: Forty-four MACEs were observed during a 4.6-year median follow-up. Significant differences in stress MPE were observed between patients with and without MACEs (4.19 ± 0.46 vs. 3.93 ± 0.40; P ≤ .01). By Kaplan-Meier analysis, the risk of MACEs was significantly higher in patients with higher stress MPE (log-rank P ≤ 01). Stress MPE and stress perfusion defect (SSS ≥ 4) were significantly associated with the risk of MACEs (hazard ratio 2.77 and 2.06, respectively, P < .05 for both) after adjustment for clinical and imaging risk predictors as identified from preliminary univariate analysis. MPE demonstrated incremental prognostic value over clinical risk factors, stress test EKG and SSS as evidenced by nested models showing improved Akaike information criterion (AIC), reclassification (global continuous net reclassification improvement [NRI]: 63), global integrated discrimination improvement (IDI: 6%), and discrimination (change in c-statistic: 0.66 vs 0.74). CONCLUSIONS: Stress MPE provided independent and incremental prognostic information for the prediction of MACEs in diabetic patients. TRIAL REGISTRATION NUMBER: NCT02316054 (12/12/2014).

Prospective diagnostic performance of semiconductor SPECT myocardial perfusion imaging: wall thickening analysis reduces the need for an additional prone acquisition.

PURPOSE: To determine whether the assessment of regional wall thickening (WT) in addition to myocardial perfusion from stress supine acquisitions could compensate for the lack of prone acquisition and the corresponding decrease in the diagnostic performance of SPECT myocardial perfusion imaging (MPI) in patients with known or suspected coronary artery disease (CAD). METHODS: The study group comprised 41 patients (123 vessels) with known or suspected CAD prospectively recruited for systematic prone and supine 201Tl stress SPECT MPI. The diagnostic performance of SPECT MPI was determined for various image sets including nongated supine images (supine NG), nongated combined prone and supine images (prone and supine NG) and gated supine images, allowing WT evaluation from NG images in addition to perfusion (supine NG + WT) using invasive coronary angiography and fractional flow reserve as the gold standards. RESULTS: The rate of false positives was significantly higher among the supine NG images (20.8%) than among either the prone and supine NG or the supine NG + WT images (3.3% and 2.7%, respectively, P < 0.05 vs. supine NG). Consequently, specificity was higher for the prone and supine NG images than for the supine NG images (96.1% vs. 76.1%, P < 0.01) and was highest for the supine NG + WT images (96.8%, P not significant vs. prone and supine NG), without significant differences in sensitivity (80.0%, 86.6% and 73.3%, respectively, P not significant for all comparisons). CONCLUSION: The diagnostic performance of supine stress SPECT MPI is improved when WT assessment of ischaemic segments is used as an additional diagnostic criterion to values not significantly different from those with combined prone and supine acquisitions.

Effectiveness of Simulation-Based Training on Transesophageal Echocardiography Learning: The SIMULATOR Randomized Clinical Trial.

Importance: Evidence is scarce on the effectiveness of simulation-based training in transesophageal echocardiography (TEE). Objective: To assess the effectiveness of simulation-based teaching vs traditional teaching of TEE knowledge and skills of cardiology fellows. Design, Setting, and Participants: Between November 2020 and November 2021, all consecutive cardiology fellows inexperienced in TEE from 42 French university centers were randomized (1:1; n = 324) into 2 groups with or without simulation support. Main Outcomes and Measures: The co-primary outcomes were the scores in the final theoretical and practical tests 3 months after the training. TEE duration and the fellows' self-assessment of their proficiency were also assessed. Results: While the theoretical and practical test scores were similar between the 2 groups (324 participants; 62.6% male; mean age, 26.4 years) before the training (33.0 [SD, 16.3] points vs 32.5 [SD, 18.5] points; P = .80 and 44.2 [SD, 25.5] points vs 46.1 [SD, 26.1] points; P = .51, respectively), the fellows in the simulation group (n = 162; 50%) displayed higher theoretical test and practical test scores after the training than those in the traditional group (n = 162; 50%) (47.2% [SD, 15.6%] vs 38.3% [SD, 19.8%]; P < .001 and 74.5% [SD, 17.7%] vs 59.0% [SD, 25.1%]; P < .001, respectively). Subgroup analyses showed that the effectiveness of the simulation training was even greater when performed at the beginning of the fellowship (ie, 2 years or less of training) (theoretical test: an increase of 11.9 points; 95% CI, 7.2-16.7 vs an increase of 4.25 points; 95% CI, -1.05 to 9.5; P = .03; practical test: an increase of 24.9 points; 95% CI, 18.5-31.0 vs an increase of 10.1 points; 95% CI, 3.9-16.0; P < .001). After the training, the duration to perform a complete TEE was significantly lower in the simulation group than in the traditional group ( 8.3 [SD, 1.4] minutes vs 9.4 [SD, 1.2] minutes; P < .001, respectively). Additionally, fellows in the simulation group felt more ready and more confident about performing a TEE alone after the training (mean score, 3.0; 95% CI, 2.9-3.2 vs mean score, 1.7; 95% CI, 1.4-1.9; P < .001 and mean score, 3.3; 95% CI, 3.1-3.5 vs mean score, 2.4; 95% CI, 2.1-2.6; P < .001, respectively). Conclusions and Relevance: Simulation-based teaching of TEE showed a significant improvement in the knowledge, skills, and self-assessment of proficiency of cardiology fellows, as well as a reduction in the amount of time needed to complete the examination. These results should encourage further investigation of clinical performance and patient benefits of TEE simulation training.

Non-invasive Multimodality Imaging of Coronary Vulnerable Patient.

Atherosclerotic plaque rupture or erosion remain the primary mechanism responsible for myocardial infarction and the major challenge of cardiovascular researchers is to develop non-invasive methods of accurate risk prediction to identify vulnerable plaques before the event occurs. Multimodal imaging, by CT-TEP or CT-SPECT, provides both morphological and activity information about the plaque and cumulates the advantages of anatomic and molecular imaging to identify vulnerability features among coronary plaques. However, the rate of acute coronary syndromes remains low and the mechanisms leading to adverse events are clearly more complex than initially assumed. Indeed, recent studies suggest that the detection of a state of vulnerability in a patient is more important than the detection of individual sites of vulnerability as a target of focal treatment. Despite this evolution of concepts, multimodal imaging offers a strong potential to assess patient's vulnerability. Here we review the current state of multimodal imaging to identify vulnerable patients, and then focus on emerging imaging techniques and precision medicine.

Prognostic significance of severe coronary microvascular dysfunction post-PCI in patients with STEMI: A systematic review and meta-analysis.

Coronary microvascular dysfunction (CMVD) is common and associated with poorer outcomes in patients with ST Segment Elevation Myocardial Infarction (STEMI). The index of microcirculatory resistance (IMR) and the index of hyperemic microvascular resistance (HMR) are both invasive indexes of microvascular resistance proposed for the diagnosis of severe CMVD after primary percutaneous coronary intervention (pPCI). However, these indexes are not routinely assessed in STEMI patients. Our main objective was to clarify the association between IMR or HMR and long-term major adverse cardiovascular events (MACE), through a systematic review and meta-analysis of observational studies. We searched Medline, PubMed, and Google Scholar for studies published in English until December 2020. The primary outcome was a composite of cardiovascular death, non-cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and rehospitalization for heart failure occurring after at least 6 months following CMVD assessment. We identified 6 studies, reporting outcomes in 1094 patients (mean age 59.7 ± 11.4 years; 18.2% of patients were women) followed-up from 6 months to 7 years. Severe CMVD, defined as IMR > 40 mmHg or HMR > 3mmHg/cm/sec was associated with MACE with a pooled HR of 3.42 [2.45; 4.79]. Severe CMVD is associated with an increased risk of long-term adverse cardiovascular events in patients with STEMI. Our results suggest that IMR and HMR are useful for the early identification of severe CMVD in patients with STEMI after PCI, and represent powerful prognostic assessments as well as new therapeutic targets for clinical intervention.

Prognostic value of right ventricular dilatation in patients with COVID-19: a multicentre study.

AIMS: Although cardiac involvement has prognostic significance in coronavirus disease 2019 (COVID-19) and is associated with severe forms, few studies have explored the prognostic role of transthoracic echocardiography (TTE). We investigated the link between TTE parameters and prognosis in COVID-19. METHODS AND RESULTS: Consecutive patients with COVID-19 admitted to 24 French hospitals were retrospectively included. Comprehensive data, including clinical and biological parameters, were recorded at admission. Focused TTE was performed during hospitalization, according to clinical indication. Patients were followed for a primary composite outcome of death or transfer to intensive care unit (ICU) during hospitalization. Among 2878 patients, 445 (15%) underwent TTE. Most of these had cardiovascular risk factors, a history of cardiovascular disease, and were on cardiovascular treatments. Dilatation and dysfunction were observed in, respectively, 12% (48/412) and 23% (102/442) of patients for the left ventricle, and in 12% (47/407) and 16% (65/402) for the right ventricle (RV). Primary composite outcome occurred in 44% (n = 196) of patients [9% (n = 42) for death without ICU transfer and 35% (n = 154) for admission to ICU]. RV dilatation was the only TTE parameter associated with the primary outcome. After adjustment, male sex [hazard ratio (HR) 1.56, 95% confidence interval (CI) 1.09 - 2.25; P = 0.02], higher body mass index (HR 1.10, 95% CI 1.02 - 1.18; P = 0.01), anticoagulation (HR 0.53, 95% CI 0.33 - 0.86; P = 0.01), and RV dilatation (HR 1.66, 95% CI 1.05 - 2.64; P = 0.03) remained independently associated with the primary outcome. CONCLUSION: Echocardiographic evaluation of RV dilatation could be useful for assessing risk of severe COVID-19 developing in hospitalized patients.

Multimodal Imaging to Understand Left Ventricular Systolic Dysfunction in a Patient With Sepsis-Related Myocardial Calcification.

A 52-year-old man with acute peritonitis developed severely decreased left ventricular (LV) ejection fraction. Multimodal imaging allowed the diagnosis of sepsis-related myocardial calcification. Moreover, 2-dimensional speckle tracking echocardiography allowed a better understanding of LV dysfunction and confirmed the hypothesis that regional LV dysfunction is in accordance with the localization of calcifications. (Level of Difficulty: Intermediate.).

Prognosis of Coronary Atherosclerotic Burden in Non-Ischemic Dilated Cardiomyopathies.

BACKGROUND: Atherosclerosis is associated with a worse prognosis in many diseases such as ischemic cardiomyopathy, but its impact in non-ischemic dilated cardiomyopathy (dCMP) is lesser known. Our aim was to study the prognostic impact of coronary atherosclerotic burden (CAB) in patients with dCMP. METHODS: Consecutive patients with dCMP and left ventricular (LV) dysfunction diagnosed by concomitant analysis of invasive coronary angiography (ICA) and CMR imaging were identified from registry-database. CAB was measured by Gensini score. The primary composite endpoint was the occurrence of major adverse cardiovascular events (MACE) defined as cardiovascular (CV) mortality, non-fatal MI and unplanned myocardial revascularization. The results of 139 patients constituting the prospective study population (mean age 59.4 ± 14.7 years old, 74% male), average LV ejection fraction was 31.1 ± 11.02%, median Gensini score was 0 (0-3), and mid-wall late gadolinium enhancement (LGE) was the most frequent LGE pattern (42%). Over a median follow-up of 2.8 years, 9% of patients presented MACE. Patients with MACE had significantly higher CAB compared to those who were free of events (0 (0-3) vs. 3.75 (2-15), p < 0.0001). CAB remained the significant predictor of MACE on multivariate logistic analysis (OR: 1.12, CI: 1.01-1.23, p = 0.02). CONCLUSION: High CAB may be a new prognostic factor in dCMP patients.

Rational and Design of the SIMULATOR Study: A Multicentre Randomized Study to Assess the Impact of SIMULation-bAsed Training on Transoesophageal echocardiOgraphy leaRning for Cardiology Residents.

Introduction: Simulation-based training in transesophageal echocardiography (TEE) seems promising. However, data are limited to non-randomized or single-center studies. To assess the impact of simulation-based vs. traditional teaching on TEE knowledge and performance for medical residents in cardiology. Materials and Methods: Nationwide prospective randomized multicenter study involving 43 centers throughout France allowing for the inclusion of >70% of all French cardiology residents. All cardiology residents naive from TEE will be included. Randomization with stratification by center will allocate residents to either a control group receiving theoretical knowledge by e-learning only, or to an intervention group receiving two simulation-based training sessions on a TEE simulator in addition. Results: All residents will undergo both a theoretical test (0-100 points) and a practical test on a TEE simulator (0-100 points) before and 3 months after the training. Satisfaction will be assessed by a 5-points Likert scale. The primary outcomes will be to compare the scores in the final theoretical and practical tests between the two groups, 3 months after the completion of the training. Conclusion: Data regarding simulation-based learning in TEE are limited to non-randomized or single-center studies. The randomized multicenter SIMULATOR study will assess the impact of simulation-based vs. traditional teaching on TEE knowledge and performance for medical residents in cardiology, and whether such an educational program should be proposed in first line for TEE teaching.