Reference values on atrial and ventricular strain from cardiovascular magnetic resonance (CMR) are essential in identifying patients with impaired atrial and ventricular function. However, reference values have not been established for Chinese subjects. One hundred and fifty healthy volunteers (75 Males/75 Females; 18–82 years) were recruited. All underwent CMR scans with images acceptable for further strain analysis. Subjects were stratified by age: Group 1, 18–44 years; Group 2, 45–59 years; Group 3, ≥60 years. Feature tracking of CMR cine imaging was used to obtain left atrial global longitudinal (LA E_ll) and circumferential strains (LA E_cc) and respective systolic strain rates, left ventricular longitudinal (LV E_ll), circumferential (LV E_cc) and radial strains (LV E_rr) and their respective strain rates, and right ventricular longitudinal strain (RV E_ll) and strain rate. LA E_ll and LA E_cc were 32.8 ± 9.2% and 40.3 ± 13.4%, respectively, and RV E_ll was −29.3 ± 6.0%. LV E_ll, LV E_cc and LV E_rr were −22.4 ± 2.9%, −24.3 ± 3.1%, and 79.0 ± 19.4%, respectively. LV E_ll and LV E_cc were higher in females than males (P < 0.05). LA E_ll, LA E_cc, and LV E_cc decreased, while LV E_rr increased with age (P < 0.05). LV E_ll and RV E_ll were not shown to be associated with age. Normal ranges for atrial and ventricular strain and strain rates are provided using CMR feature tracking in Chinese subjects.

Aims: The impact of different left ventricular ejection fraction (LVEF) assessed by echocardiography (EC) and cardiac magnetic resonance (CMR) on clinical diagnosis and management that could be critical in clinical practice remains unclear. This study investigated this impact for patients who underwent both exams in a real-world clinical practice. Methods: 500 patients who underwent CMR and two-dimensional EC were retrospectively included in present study. EC-measured LVEF and CMR-measured LVEF were compared. A 50% cut-off of LVEF was chosen to assess the effect of the difference between these two modalities on disease diagnosis, and a 35% cut-off was chosen for disease management, respectively. For those patients who received device therapy or coronary artery bypass grafting (CABG), the study compared the LVEF between EC and CMR with the current guideline for therapy recommendation. Results: EC-LVEF and CMR-LVEF were positively correlated, but EC-LVEF was significantly larger than CMR-LVEF (P < 0.001). Three patient groups were examined: (I) CMR-LVEF ≥ 50%, (II) 35% < CMR-LVEF < 50%, and (III) CMR-LVEF ≤ 35%. Overall, 139 of 500 patients showed inconsistent measures. There were more inconsistent measures between the two modalities in group III than group I (41.6% for group III vs. 4.1% for group I). In patients who received device therapy or CABG, 97.6% of the CMR-measured LVEF were consistent with the guideline, but only 61.0% consistent EC-measured LVEF. Conclusion: For patients with lower LVEF and planning to receive device therapy or cardiac surgery, it should be cautious to applying the recommended cut-off values to CMR-measured LVEF because its inconsistency with EC-measured LVEF.

BACKGROUND: Microvascular obstruction (MVO) is associated with heart failure (HF) following ST-segment–elevation myocardial infarction. Angiography-derived microcirculatory resistance (AMR), a wire- and adenosine-free measure, may facilitate early assessment of microvascular function post-primary percutaneous coronary intervention. This study aimed to evaluate the ability of AMR to detect MVO and its prognostic value for predicting HF in patients with ST-segment–elevation myocardial infarction post-primary percutaneous coronary intervention. METHODS: Patients with consecutive ST-segment–elevation myocardial infarction undergoing primary percutaneous coronary intervention with a cardiac magnetic resonance examination 2 to 7 days post-procedure between April 2016 and February 2023 were retrospectively reviewed. AMR was computed from coronary angiography. MVO was identified and quantified via cardiac magnetic resonance. The end point was new-onset HF during follow-up. RESULTS: Overall, 475 patients (aged 56.8±11.7 years; 399 men) were included. The area under the curve for AMR to detect MVO was 0.821 (95% CI, 0.782–0.859), with an optimal cutoff value of 2.7 mm Hg*s/cm. During a median follow-up of 37.3 months, 121 (25.5%) patients developed HF. AMR, whether as a continuous (per 0.5-mm Hg*s/cm increase; hazard ratio, 1.29 [95% CI, 1.10–1.52]; P =0.002) or categorical (AMR >2.7 mm Hg*s/cm; hazard ratio, 2.15 [95% CI, 1.43–3.22]; P <0.001) variable, was independently associated with HF after adjusting for traditional risk factors (age, symptom-to-balloon time, left anterior descending coronary artery, and ejection fraction) and late gadolinium enhancement-cardiac magnetic resonance parameters. AMR improved prognostication over traditional risk factors and late gadolinium enhancement-cardiac magnetic resonance parameters (net reclassification improvement, 0.533; P <0.001; integrative discrimination index, 0.023; P =0.005). CONCLUSIONS: AMR showed good diagnostic performance in detecting MVO and was an independent and incremental predictor of HF in patients with ST-segment–elevation myocardial infarction post-primary percutaneous coronary intervention.

This study sought to investigate whether left ventricular (LV) fibrosis quantified by T1 mapping can be used as a biomarker to predict outcome in patients with atrial fibrillation (AF) and heart failure (HF). 108 patients with AF and HF were included in this study. They underwent cardiac magnetic resonance, including T1 mapping sequence to assess LV fibrosis between May 2014 to May 2016. Patients received catheter ablation for AF and pharmacological treatment for HF. The primary endpoint was a composite adverse outcome of cardiac death, subsequent HF or stroke, subsequent HF was the secondary endpoint. During follow up (median: 23 months, Q1-Q3: 11 to 28 months), 1 cardiac death, 12 strokes, and 42 HF episodes occurred. LV extracellular volume fraction (ECV) was predictive of composite adverse outcome and subsequent HF (all p < 0.001). In multivariable analysis, LV ECV was an independent predictor of composite adverse outcome (hazard ratio (HR): 1.258, 95% confidence interval (CI): 1.140–1.388, p < 0.001) and subsequent HF (HR: 1.223, 95% CI: 1.098–1.363, p < 0.001). LV fibrosis measured by T1 mapping indices significantly predicts composite adverse outcomes and subsequent HF in patients with AF and HF.