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.

Background: Premature acute myocardial infarction (AMI) has become an important public health challenge. Young survivors face prolonged residual cardiovascular risk, yet real-world implementation of long-term secondary prevention across medication use, health behaviors, and risk-factor monitoring remains insufficiently characterized in China. Methods: In this hospital-based cross-sectional study, we included 1377 young AMI survivors aged 18–44 years who attended follow-up at Beijing Anzhen Hospital between 2023 and 2025. Current use of major secondary prevention medications, achievement of four health-behavior targets (smoking abstinence/cessation, physical activity, diet, and sleep), and lipid monitoring during the preceding 12 months were assessed using standardized interviews and medical records. Recurrent myocardial infarction (MI) and repeat coronary revascularization occurring between discharge after the index AMI and the study visit were retrospectively identified. Multivariable logistic regression was used to examine associations between secondary-prevention implementation domains and recurrent events. Results: Participants had a mean age of 39.1 years, and 95.9% were male. Recurrent MI occurred in 9.2% and repeat revascularization in 13.7%. The proportion concurrently using four major medication classes decreased from 50.0% at discharge to 25.9% at follow-up. Overall, 45.1% achieved good behavioral implementation, defined as meeting at least three of four ideal behaviors. In fully adjusted models, good behavioral implementation was associated with lower odds of recurrent MI (odds ratio [OR] 0.49, 95% confidence interval [CI] 0.32–0.73) and repeat revascularization (OR 0.72, 95% CI 0.52–1.00). Concurrent use of all four medication classes and frequent lipid monitoring were not independently associated with recurrent outcomes. Conclusions: Among young AMI survivors in China, substantial gaps in long-term secondary prevention were observed, particularly for healthy behaviors. These findings support the public health importance of strengthening lifestyle-oriented and multidisciplinary follow-up strategies for young survivors of AMI. Because exposure and outcome periods overlapped partially, findings should be interpreted as associational rather than causal.