Reduced 123I-BMIPP uptake implies decreased myocardial flow reserve in patients with chronic stable angina

Purpose Long-chain fatty acid (LCFA) is the main energy source for normal myocardium at rest, but in ischemic myocardium, the main energy substrate shifts from LCFA to glucose. 123I-BMIPP is a radiolabeled LCFA analog. In chronic stable angina without previous infarction, we suppose that reduced 123I-BMIPP uptake is related to the substrate shift in myocardium with decreased myocardial flow reserve (MFR). The purpose of this study was to relate 123I-BMIPP uptake to rest myocardial blood flow (MBF), hyperemic MBF, and MFR assessed with 15O-water positron emission tomography (PET). Methods We enrolled 21 patients with chronic stable angina without previous infarction, all of whom underwent 123I-BMIPP single-photon emission computed tomography (SPECT) and 15O-water PET. The left ventricle was divided into 13 segments. In each segment, rest MBF and hyperemic MBF were measured by PET. 123I-BMIPP uptake was evaluated as follows: score 0=normal, 1=slightly decreased uptake, 2=moderately decreased uptake, 3=severely decreased uptake, and 4=complete defect. 123I-BMIPP uptake was compared with rest MBF, hyperemic MBF, and MFR. Results The numbers of segments with 123I-BMIPP scores 0, 1, 2, 3, and 4 were 178, 40, 25, 24, and 0, respectively. The rest MBFs for scores 0, 1, 2, and 3 were 0.93±0.25, 0.86±0.21, 0.97±0.30, and 0.99±0.37 ml/min/g, respectively. The hyperemic MBFs for scores 0, 1, 2, and 3 were 2.76±1.29, 1.84±0.74, 1.37±0.39, and 1.08±0.40 ml/min/g, respectively. The MFRs for scores 0, 1, 2, and 3 were 3.01±1.38, 2.20±0.95, 1.44±0.22, and 1.10±0.26, respectively. As 123I-BMIPP uptake declined, hyperemic MBF and MFR decreased. Conclusion In chronic stable angina without previous infarction, reduced 123I-BMIPP uptake implies decreased MFR

Impact of renal dysfunction on the choice of diagnostic imaging, treatment strategy, and outcomes in patients with stable angina

We investigated the interaction between the prognostic impact of a decrease in eGFR and the choice of initial diagnostic imaging modality for coronary artery disease. Out of 2878 patients who enrolled in the J-COMPASS study, 2780 patients underwent single photon emission computed tomography (SPECT), coronary computed tomography (CT) angiography, or coronary angiography (CAG) as an initial diagnostic test. After excluding patients with routine hemodialysis or lacked serum creatinine levels, 2096 patients in the non-decreased eGFR group (eGFR ≥ 60 ml/min/1.73 m²) and 557 patients in the decreased eGFR group (eGFR < 60 ml/min/1.73 m²) were analyzed in this study. Major adverse cardiac events, including death, myocardial infarction, heart failure hospitalization, and late revascularization, were followed, with a median follow-up duration of 472 days. SPECT or CAG was preferable to CT in patients in the decreased eGFR group (p < 0.0001 and p = 0.0024, respectively). There was a marginally significant interaction between the prognostic impact of a decrease in eGFR and the choice of diagnostic imaging modality (interaction-p = 0.056). A decrease in eGFR was not associated with a poor outcome in patients who underwent CT, while a decrease in eGFR was associated with poor outcomes in patients who underwent SPECT or CAG. In conclusion, the prognostic impact of a decrease in eGFR tended to be different among the initial imaging modalities

Association of coronary revascularisation after physician-referred non-invasive diagnostic imaging tests with outcomes in patients with suspected coronary artery disease: a post hoc subgroup analysis

Objective: We aimed to evaluate the association of the prognostic impact of coronary revascularisation with physician-referred non-invasive diagnostic imaging tests (single photon emission CT (SPECT) vs coronary CT angiography) for coronary artery disease. Design: A post hoc analysis of a subgroup from the patient cohort recruited for the Japanese Coronary-Angiography or Myocardial Imaging for Angina Pectoris Study. Setting: Multiple centres in Japan. Participants: From the data of 2780 patients with stable angina, enrolled prospectively between January 2006 and March 2008 in Japan, who had undergone physician-referred non-invasive imaging tests, 1205 patients with SPECT as an initial strategy and 625 with CT as an initial strategy were analysed. We assessed the effect of revascularisation (within 90 days) in each diagnostic imaging stratum and the interaction between the two strata. Primary and secondary outcome measures: Major adverse cardiac events (MACEs), including death, myocardial infarction, hospitalisation for heart failure and late revascularisation, were followed up for 1 year. The χ2 test, Student’s t-test, Kaplan-Meier analysis, log-rank test and multivariable Cox proportional hazard model were used in data analysis. Results: A total of 210 (17.4%) patients in the SPECT stratum and 149 (23.8%) in the CT stratum underwent revascularisation. Although in each stratum, the cumulative 1 year incidence of MACEs was significantly higher in patients who underwent revascularisation than in those who did not (SPECT stratum: 9.1 vs 1.2%, log-rank p<0.0001; CT stratum: 6.1 vs 0.8%, log-rank p=0.0001), there was no interaction between the risk of revascularisation and the imaging strata (SPECT stratum: adjusted HR (95% CI), 4.25 (1.86–9.72); CT stratum: 4.13 (1.16–14.73); interaction: p=0.97). Conclusion: The association of revascularisation with the outcomes of patients with suspected coronary artery disease was not different between SPECT-first and CT-first strategies in a physician-referred fashion

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

15O-labeled Water is the Best Myocardial Blood Flow Tracer for Precise MBF Quantification

Oxygen-15-labeled water (15O-H2O) is used as a radiopharmaceutical tracer with positron emission tomography (PET). Its short radioactive half-life permits consecutive rest and stress imaging acquisition while requiring an on-site cyclotron near a PET imaging system. 15O-H2O PET has the disadvantage of being less than ideal for visual assessment; however, its high extraction fraction allows for highly accurate quantification of myocardial blood flow (MBF). Therefore, 15O-H2O is considered to be a gold standard for MBF quantification. This is one of the great advantages of 15O-H2O PET over other PET myocardial perfusion imaging modalities. The purpose of this review is to provide the advantages and characteristics of 15O-H2O PET

Accelerated Tc-99m Sestamibi Clearance Associated with Mitochondrial Dysfunction and Improvement of Regional Left Ventricular Wall Motion in Patients with Reperfused Acute Coronary Syndrome

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Repeatability of Rest and Hyperemic Myocardial Blood Flow Measurements with 82Rb Dynamic PET

The repeatability of rest and hyperemic myocardial blood flow (MBF) measurements using 82Rb PET has not been evaluated. The aimof this study was to investigate the short-term repeatability of such measurements. Methods: Fifteen healthy volunteers underwent rest and pharmacologic stress 82Rb PET, repeated 60 min apart. Results: There was no significant difference in repeated rest MBF (0.77 6 0.25 vs. 0.82 6 0.25 mL/min/g, P 5 0.31; mean difference, 6.18% 6 12.22%) or repeated hyperemic MBF (3.35 6 1.37 vs. 3.39 6 1.37 mL/min/g, P 5 0.81; mean difference, 1.17% 6 13.64%). The repeatability coefficients were 0.19 mL/min/g for rest MBF and 0.92 mL/min/g for hyperemia. Conclusion:MBF using 82Rb is highly reproducible using a sameday short-term repeatability protocol. Serial MBF measurements with 82Rb PET should have the ability to quantify the acute effects of therapeutic interventions on MBF

Regional evaluation of cardiac sympathetic nervous activity in patients with paroxysmal atrial fibrillation using C-11 hydroxyephedrine PET/CT

後日記入予定Society of Nuclear Medicin