Lijun Zhang

Background: The relationship between left atrial (LA) size, LA strain, and long-term prognosis in patients with coronary chronic total occlusion (CTO) remains unclear. This study aimed to evaluate the association of LA size and LA strain with clinical outcomes in CTO patients using cardiac magnetic resonance (CMR). Methods: This retrospective study included 168 patients with left ventricular ejection fraction (LVEF) ≥ 40%. The primary endpoint was the composite of major adverse cardiovascular and cerebrovascular events (MACCE). Model 1 was established by adjusting for clinically relevant parameters and standard CMR metrics. Models 2–4 were developed using Cox regression based on Model 1, with additional adjustment for each LA strain parameter separately. Results: A total of 168 patients with an LVEF ≥ 40% were analyzed, of whom 39 (23.2%) experienced MACCE during a mean follow-up of 45.9 months (median, 42 months). A preliminary model suggested that LA maximum volume index (LAVI_max) was independently associated with MACCE (HR 1.05, 95% CI 1.02–1.08, p = 0.004). Specifically, compared to the first quartile of LAVI_max, the second, third, and fourth quartiles were associated with an increased risk of MACCE (Q2: HR 4.50, 95% CI 1.42–14.27, p = 0.011; Q3: HR 4.40, 95% CI 1.29–14.96, p = 0.018; Q4: HR 5.55, 95% CI 1.71–18.06, p = 0.004). In Models 2–4, higher LAVI_max remained independently associated with MACCE (all p < 0.05), after adjusting for LA reservoir strain, conduit strain and booster strain, separately. In contrast, none of the LA strain parameters were associated with MACCE. Conclusions: Among CTO patients with LVEF ≥ 40%, LAVI_max was independently associated with MACCE.

With the advancement of fractional flow reserve (FFR) derived from computed tomography (FFR_CT), virtual stenting technology has gradually developed. This study investigated the performance of virtual stenting based on FFR_CT in predicting post-percutaneous coronary intervention (PCI) FFR. Data from 75 patients (78 blood vessels) was collected retrospectively. We randomly allocated the participants to discovery (n = 26) and validation (n = 52) cohorts. The FFR_CT was calculated using pre-PCI coronary computed tomography angiography images. Virtual stent implantation was simulated using blinded and non-blinded virtual stenting methods to obtain post-virtual stenting FFR_CT. The median FFR_CT before PCI and invasive FFR were 0.70 (0.60–0.77) and 0.69 (0.63–0.76), respectively. The median FFR_CT were 0.91 (0.86–0.95) and 0.91 (0.87–0.94) in the blinded and non-blinded groups, respectively; the invasive post-PCI FFR was 0.90 (0.88–0.93). The difference between the FFR_CT after using the blinded/non-blinded method and the invasive post-PCI FFR were 0.010 (95% limits of agreement: −0.064 to 0.084) and 0.009 (−0.050 to 0.068) in the discovery cohort and −0.005 (−0.075 to 0.064) and −0.0002 (−0.064 to 0.064) in the validation cohort, respectively. Virtual stenting technology based on FFR_CT can effectively predict functional outcomes after PCI and could be a reliable tool for PCI procedural planning.

Background: The impact of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) on myocardial function remains controversial. This study aims to evaluate changes in myocardial function following CTO-PCI using cardiac magnetic resonance (CMR) imaging and to identify the patient subgroups that derive the greatest benefit from CTO artery recanalization. Methods: We retrospectively screened 652 patients diagnosed with single-vessel CTO through coronary angiography at Beijing Anzhen Hospital between December 2014 and July 2023. Among these, 303 patients underwent baseline CMR imaging, and 115 completed follow-up imaging. A total of 108 patients met the inclusion criteria, with 71 receiving PCI and 37 undergoing optimal medical therapy (OMT). Myocardial viability and cardiac function indices, including left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and late gadolinium enhancement (LGE) were assessed using CMR. In the subgroup analysis, patients were categorized by LVEF based on clinical consensus (normal: ≥50%; decreased: Results: There were no significant differences between the PCI and OMT groups in baseline characteristics, including age (56.96±10.69 vs. 54.16±11.32 years, P=0.21) and gender distribution [57 (80.3%) vs. 33 (89.2%), P=0.24]. No differences were observed between the PCI and OMT groups in LVEF (61.00%±9.40% vs. 59.68%±9.33%, P=0.50), LVEDV (126.53±31.41 vs. 125.93±29.26 mL, P=0.93), or LVESV [47.09 (35.22, 61.11) vs. 51.41 (36.73, 62.07) mL, P=0.68] at a median follow-up time of 12 months. Additionally, no changes in LVEF, LVEDV, or LVESV were found following PCI (P>0.05). However, in patients with baseline LVEF vs. 61.13% (47.48%, 64.54%), P=0.01]. In patients with baseline LVEF 50%, LVEF was not significantly affected by PCI [43.22% (40.23%, 45.54%) vs. 46.03% (40.75%, 59.06%), P=0.11]. Patients with LVEF ≥50% showed no myocardial function improvements post-PCI, regardless of segmental LGE percentages (P>0.05). Conclusions: Baseline LVEF and myocardial viability assessed via quantitative CMR imaging before CTO-PCI may help select patients who will benefit from the procedure. Although overall LVEF did not improve following CTO-PCI, patients with baseline LVEF <50% and segmental LGE ≤50% benefited more, suggesting the procedure can enhance myocardial function recovery in certain patient groups and confirming the safety and efficacy of CTO-PCI.

Background: Coronary microvascular dysfunction (CMD) has been suggested to be one of the pathologic mechanisms contributing to heart failure with preserved left ventricular ejection fraction (LVEF) and left ventricular (LV) diastolic dysfunction. We therefore aimed to evaluate LV diastolic function in patients with CMD using cardiovascular magnetic resonance feature tracking (CMR-FT). Methods: We prospectively enrolled 115 patients referred to cardiology clinics for chest pain assessment who subsequently underwent coronary computed tomography angiogram and stress perfusion CMR. CMD was defined as the presence of subendocardial inducible ischemia detected through visual assessment. LV diastolic function was evaluated using CMR-derived volume-time curves and CMR-FT parameters. The former included early peak filling rate (PFR) and time to PFR; the latter included LV global/regional peak longitudinal diastolic strain rate (LDSR), circumferential diastolic strain rate (CDSR), and radial diastolic strain rate (RDSR). Results: A total of 92 patients with 1,312 segments were eventually included. Of these, 19 patients were classified as non-CMD (48.8±11.2 years; 63.2% male) and 73 as with CMD (52.3±11.9 years; 54.8% male). The LVEFs were similar and preserved in both groups (P=0.266). At the per-patient level, no differences were observed in PFR, time to PFR, or LV global diastolic strain rates between the two groups. At the per-segment level, 51% (665/1,312) of the myocardial segments were classified as CMD, whereas 49% (647/1,312) were classified as non-CMD. CMD segments showed significantly lower regional CDSR (P=0.019) and RDSR (P=0.006) compared with non-CMD segments. Conclusions: Despite normal LV ejection fraction in CMD patients, decreased LV diastolic function in CMD myocardial segments indicates early diastolic impairment.