Myocardial Extracellular Volume Fraction and T1 Mapping by Cardiac Magnetic Resonance Compared Between Patients With and Without Type 2 Diabetes, and the Effect of ECV and T2D on Cardiovascular Outcomes

Background: To investigate the difference in myocardial extracellular volume fraction (ECV) by cardiac magnetic resonance (CMR) T1 mapping between patients with and without type 2 diabetes (T2D), and the effect of ECV and T2D on cardiovascular (CV) outcomes.Methods: All patients aged > 18 years with known or suspected coronary artery disease who underwent CMR for assessment of myocardial ischemia or myocardial viability at the Department of Cardiology of the Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand from September 2017 to December 2018 were screened for inclusion eligibility. Left ventricular ejection fraction (LVEF), late gadolinium enhancement, and T1 mapping were performed. ECV values were derived from myocardial native T1 and contrast-enhanced T1 values that were obtained using modified Look-Locker inversion recovery at the septum of the mid-cavity short-axis map. Demographic data, clinical characteristics, and CV outcomes were collected by retrospective chart review. Composite CV outcomes included CV death, acute coronary syndrome, heart failure hospitalization, or ventricular tachycardia (VT)/ventricular fibrillation.Results: A total of 739 subjects (mean age: 69.5 ± 14.0 years, 49.3% men) were included. Of those, 188 subjects had T2D (25.4%). ECV was significantly higher in T2D than in non-T2D (30.0 ± 5.9% vs. 28.8 ± 4.7%, p = 0.004). During the mean follow-up duration of 26.2 ± 8.5 months, 43 patients (5.8%) had a clinical composite outcome, as follows: three CV death (0.4%), seven acute coronary syndrome (0.9%), 33 heart failure hospitalization (4.5%), and one VT (0.1%). T2D, low LVEF, and high ECV were all identified as independent predictors of CV events. Patients with T2D and high ECV had the highest risk of CV events.Conclusion: Among patients with known or suspected coronary artery disease, patients with T2D had a higher ECV. T2D and high ECV were both found to be independent risk factors for adverse CV outcomes.

Cardiac Care of Non-COVID-19 Patients During the SARS-CoV-2 Pandemic: The Pivotal Role of CCTA

Aim: The aim of this study is to evaluate the potential use of coronary CT angiography (CCTA) as the sole available non-invasive diagnostic technique for suspected coronary artery disease (CAD) during the coronavirus disease 2019 (COVID-19) pandemic causing limited access to the hospital facilities.Methods and Results: A consecutive cohort of patients with suspected stable CAD and clinical indication to non-invasive test was enrolled in a hub hospital in Milan, Italy, from March 9 to April 30, 2020. Outcome measures were obtained as follows: cardiac death, ST-elevation myocardial infarction (STEMI), non-ST-elevation myocardial infarction (NSTEMI), and unstable angina. All the changes in medical therapy following the result of CCTA were annotated. A total of 58 patients with a mean age of 64 ± 11 years (36 men and 22 women) were enrolled. CCTA showed no CAD in 14 patients (24.1%), non-obstructive CAD in 30 (51.7%) patients, and obstructive CAD in 14 (24.1%) patients. Invasive coronary angiography (ICA) was considered deferrable in 48 (82.8%) patients. No clinical events were recorded after a mean follow-up of 376.4 ± 32.1 days. Changes in the medical therapy were significantly more prevalent in patients with vs. those without CAD at CCTA.Conclusion: The results of the study confirm the capability of CCTA to safely defer ICA in the majority of symptomatic patients and to correctly identify those with critical coronary stenoses necessitating coronary revascularization. This characteristic could be really helpful especially when the hospital resources are limited

Predictors of CT-derived FFR in patients with suspected CAD beyond severity of coronary stenosis

Background Functional assessment of coronary stenosis using computational fluid dynamics is increasingly used, however other factors besides coronary stenosis may affect the results. We assessed several predictors for CT-derived fractional flow reserve (CT-FFR) in patients with suspected coronary artery disease (CAD) undergoing coronary computed tomographic angiography (CCTA). Methods 2505 consecutive patients with suspected CAD undergoing CCTA from 2008 to 2016 were screened, 1549 were excluded due to incomplete data (934), image quality (345), software error (147) or other reasons (123). Minimal CT-FFR was measured using an on-site prototype (cFFR Version 3.0, Siemens Healthineers, Forchheim, Germany) in coronaries ≥2mm. Several clinical as well as technical criteria were assessed for predicting the minimal CT-FFR per patient. Results 956 patients (51±12 years, 51.2% men) were included in this analysis. Mean EF was 59.4±7.4%, heart rate 63±9 bpm, systolic (126.5±20mmHg) and diastolic (70±11 mmHg) blood pressure (BP). Regression analysis and ANOVA showed low but significant impact on minimal CT-FFR (mean 0.85±0.10) by EF, aortic valvular dysfunction, heart rate and systolic blood pressure as well as image quality (esp. blooming and image noise). See Tables 1 and 2. Conclusion Coronary stenosis may not be the only relevant predictor for CT-FFR. Several clinical criteria (EF, heart rate, BP, aortic valve dysfunction) as well as image criteria (image quality, artifacts) can affect CT-FFR results. FUNDunding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Cleveland Clinic Foundation Table 1. ANOVA analysis Table 2. Regression analysis

Left ventricular longitudinal strain impairment at rest correlates with reduction of SPECT-derived coronary flow reserve in patients with suspected coronary artery disease

Background Speckle tracking echocardiography (STE) may be useful for the detection of subclinical systolic function abnormalities. Dynamic acquisition of myocardial blood flow using 99mTc-MIBI SPECT-CZT gamma camera allows the calculation of coronary flow reserve (CFR). Purpose The aim of our study is to assess the relationship between left ventricular longitudinal strain (LS) and CFR in patients with suspected coronary artery disease (CAD). Methods 55 patients (pts) (43.6% females, mean age 64.6±8.4 years) with suspected CAD underwent transthoracic echocardiography with assessment global and local LS by STE. We calculated mean global left ventricular LS (GLS), as well as LS of individual coronary artery territories (LAD LS, LCx LS and RCA LS). All pts underwent myocardial perfusion study with novel solid-state CZT nuclear camera (dipyridamole stress protocol). We measured CFR of the left ventricle and individual coronary territories. Results Mean absolute GLS in pts with total CFR <2 was significantly lower than in pts with CFR >2 (median value −13.9 vs −18.3; p<0.001). Similar differences were observed in all three coronary territories (p≤0.01). Modest but significant correlations were detected between total CFR and GLS values (r=−0.56; p<0.001), LAD CFR and LAD LS (r=−0.54; p<0.001), RCA CFR and RCA LS (r=−0.36; p=0.007), LCx CFR and LCx LS (r=−0.53; p<0.001). GLS at rest had good diagnostic value for detecting total CFR <2 (AUC=0.767; p<0.001). The criterion with the highest diagnostic accuracy was GLS > (−15.8) – its sensitivity was 68%, specificity 77.7%, and overall accuracy 73%. Conclusions Indices of left ventricular longitudinal function obtained by speckle tracking echocardiography correlate with SPECT-derived CFR in patients with suspected CAD. FUNDunding Acknowledgement Type of funding sources: None.