BACKGROUND:The electrocardiographic (ECG) presentation, with or without ST-segment elevation, has traditionally been the cornerstone for classifying and managing acute myocardial infarction (AMI). However, up to 20% of non-ST-segment elevation myocardial infarction (NSTEMI) patients may have a completely occluded infarct-related artery, which could have important prognostic implications regardless of ECG findings. AIM:To determine the prevalence, predictors, and impact of total occlusion of the infarct-related coronary artery on short-term mortality. METHODS:We conducted a prospective, single-center cohort study that included consecutive patients treated for AMI with percutaneous coronary intervention (PCI) at the University Hospital Centre Sestre Milosrdnice in Zagreb, Croatia, between 2011 and 2018. Patients were divided into two groups based on the patency of the infarct-related artery: Those with an occluded coronary artery (OCA) and those with a patent coronary artery (PCA). RESULTS:Among the 2483 patients (71.6% male) treated with PCI for AMI, 67.9% had an OCA, while 32.1% had a patent artery (PCA). Notably, 35.5% of NSTEMI patients had an OCA. Patients with OCA were younger, had fewer chronic comorbidities, and presented with more severe clinical symptoms. In contrast, patients with PCA were older and exhibited more extensive chronic atherosclerotic disease. Thirty-day mortality was significantly higher in the OCA group (7.29%) compared to the PCA group (3.52%, P < 0.001). OCA was identified as an independent predictor of mortality [hazard ratio (HR) = 3.0367, 95% confidence interval (CI): 1.4543-6.3411]. Other independent predictors included age (HR = 1.0626; 95%CI: 1.0341-1.0919), Global Registry of Acute Coronary Events score (HR = 1.0065; 95%CI: 1.0011-1.0120), and ventricular tachycardia before or during PCI (HR = 3.8458; 95%CI: 1.4600-10.1299). ECG presentation (STEMI vs NSTEMI) was not an independent prognostic factor (HR = 1.0404; 95%CI: 0.5659-1.9128). Chronic statin therapy prior to AMI [odds ratios (OR) = 0.0168, 95%CI: 0.3674-0.9057], older age (OR = 0.0023, 95%CI: 0.9547-0.9900), and lower troponin I values (OR = 1.0000, 95%CI: 1.0000-1.0001) were associated with a lower likelihood of having an OCA. CONCLUSION:Culprit-artery occlusion is a strong, independent determinant of short-term mortality. An occlusion-aware perspective refines risk stratification beyond ECG presentation and supports earlier invasive evaluation in NSTEMI patients with clinical/ECG signs of possible occlusion.

Background Junctional ectopic tachycardia (JET) is a well-recognized postoperative arrhythmia in pediatric patients but is rarely described in adults following cardiac surgery. Case Summary A 31-year-old man developed acute dyspnea and palpitations on postoperative day 4 following aortic valve replacement and ascending aorta replacement. Telemetry revealed sustained narrow-complex tachycardia with atrioventricular dissociation, ventricular predominance (V > A), and QRS morphology identical to sinus rhythm. Other causes of postoperative tachycardia were systematically excluded, and JET was diagnosed. Conservative management resulted in spontaneous resolution of the arrhythmia. Discussion JET is an uncommon but important cause of postoperative tachycardia in adults. This case emphasizes the diagnostic value of careful electrocardiogram analysis in differentiating JET from other narrow-complex tachycardias and preventing unnecessary interventions. Take-Home Messages JET should be considered in adults presenting with postoperative narrow-complex tachycardia and atrioventricular dissociation. Accurate electrocardiogram interpretation is essential for appropriate management.

BACKGROUND:Ventricular late potentials (VLPs) are markers of arrhythmogenic substrate, but conventional assessment using signal-averaged ECG (SAECG) requires prolonged acquisition and operator-dependent artifact handling, limiting scalability and ambulatory use. Single-beat detection of VLP-like activity from standard surface ECG remains insufficiently validated. OBJECTIVE:To evaluate the technical feasibility of interpretable single-beat detection of VLP-like perturbations from standard ECG leads without signal averaging. METHODS:Using the MIMIC-IV-ECG database, we analyzed 120,000 beats from leads II, V2, and V6. Because large public datasets with beat-level clinically adjudicated VLP labels are not currently available, physiologically constrained synthetic VLP-like signals were injected into a subset of beats to create a controlled feasibility benchmark. For each beat, more than 200 features were extracted, including time-domain statistics, frequency-domain measures, wavelet coefficients, autocorrelation features, and localized windowed summaries. Ten classifiers were optimized using nested patient-wise cross-validation and evaluated in five settings: single-lead detection, cross-lead generalization, mixed-lead training, reduced training size, and class-imbalance robustness. RESULTS:Gradient-boosted ensembles, particularly XGBoost and CatBoost, achieved strong discrimination on held-out single-beat data (AUC > 0.99; F1 > 0.93), while remaining stable with 10% of the training data and 5% positive-class prevalence. Performance was also robust in lead-transfer experiments. SHAP analysis identified localized entropy, dispersion, and related high-frequency descriptors in late post-R windows as the dominant predictors. CONCLUSION:These findings support the methodological feasibility of interpretable single-beat detection of VLP-like signatures from routine surface ECG under controlled synthetic conditions. Validation on clinically adjudicated cohorts and external datasets is required before clinical translation.

BACKGROUND:Early-onset myocardial infarction (MI) has substantial consequences and sex-specific risk profiles. Psychosocial stressors and mental health may influence MI recovery. OBJECTIVES:To examine sex differences in pre-MI psychosocial stressors, post-discharge mental health pathways, cardiac rehabilitation (CR), and 12-month secondary prevention. METHODS:In this observational two-centre cohort (2021-2024), consecutive adults aged ≤45 years with confirmed MI and coronary angiography completed psychosocial questionnaires during hospitalisation; first-ever MI was not required. Telephone follow-up at 12 ± 3 months assessed mental health care, CR, LDL cholesterol, smoking, exercise, and psychiatric diagnoses. RESULTS:Among 301 patients (214 men, 87 women; median age 43 years), 16 (5.3%) had prior MI. Women more often had MINOCA or SCAD and reported acute emotional stress before MI (58.6%vs 11.7%), serious family illness (18.4%vs 3.7%), and a child with special health care needs (20.7%vs 4.2%). Women had higher GAD-2 and PHQ-2 scores. Most patients reported no physician-initiated mental health discussion (78.4%), particularly men (82.9%vs 67.1%); women more often sought help (36.5%vs 16.1%). CR referral/attendance did not differ by sex. At follow-up, LDL decreased from 3.6 to 1.7 mmol/L and smoking from 78.5% to 46.8%. CONCLUSION:Psychosocial stressors and psychological symptoms differed by sex, while clinician-initiated mental health discussions were uncommon. Findings are associative and hypothesis-generating, supporting psychosocial screening and referral pathways in cardiology follow-up and CR.

Background As artificial intelligence and large language models continue to evolve, their application in health care is expanding. OpenAI’s Chat Generative Pre-trained Transformer 4 (ChatGPT-4) represents the latest advancement in this technology, capable of engaging in complex dialogues and providing information. Objective This study explores the correctness of ChatGPT-4 in informing patients about atrial fibrillation. Methods This cross-sectional observational study involved ChatGPT-4 in responding to a structured set of 108 questions across 10 categories related to atrial fibrillation. These categories included basic information, treatment options, lifestyle adjustments, and more, reflecting common patient inquiries. The model's responses were evaluated by a panel of 3 cardiologists on the basis of accuracy, comprehensiveness, clarity, relevance to clinical practice, and patient safety. The total correctness of ChatGPT-4 was quantitatively assessed through scores assigned in each category, and statistical analysis was performed to identify significant differences in performance across categories. Results ChatGPT-4 provided correct and relevant answers with considerable variability across categories. It excelled in "Lifestyle Adjustments" and "Daily Life and Management" with perfect and near-perfect scores but struggled with "Miscellaneous Concerns" scoring lower. Statistical analysis confirmed significant differences in total scores across categories (P = .020). Conclusion Our results suggest that while ChatGPT-4 is reliable in categories with structured and direct queries, it shows limitations when handling complex medical queries that require in-depth explanations or clinical judgment. ChatGPT-4 demonstrates promising potential as a tool for patient-focused informing in atrial fibrillation, particularly in straightforward informing content.

Background and Objectives: Older patients with ACS are less frequently treated with an invasive strategy, which may negatively impact their survival. This study aimed to investigate treatment approaches in elderly ACS patients and compare outcomes between invasively and conservatively treated groups. Materials and Methods: This retrospective study included consecutive patients aged 80 or older who presented with ACS at two tertiary institutions from November 2018 to October 2023. The invasive group consisted of patients who underwent percutaneous or surgical revascularization. The conservative strategy was defined as guideline-directed medical therapy only. The primary outcome was all-cause mortality during the six-month follow-up. Secondary outcomes were recurrent MI and CVI. Results: Among 670 ACS patients with a median age of 83 years (81–86) and 50.6% women, 429 (64%) were treated with an invasive strategy, and 241 (36%) were treated with a conservative strategy. A total of 176 (26%) patients died during the six-month follow-up period, with significantly higher mortality observed in the conservatively treated group compared to the invasively treated group (ACS: 37.8% vs. 19.3%, p < 0.001; STEMI: 49.4% vs. 26.8%, p < 0.001; NSTE-ACS: 32.1% vs. 10.9%, p < 0.001). Recurrent MI was documented in 2.5% of patients, while CVI occurred in 1.2%, with no difference between the treatment groups. Multivariable regression analysis identified invasive strategy (HR = 0.48; 95% CI: 0.33–0.71; p < 0.001) as a positive predictor of six-month survival in ACS patients. Conclusions: The invasive treatment strategy was associated with lower mortality in older ACS patients, regardless of the type of ACS. The incidence of recurrent MI and CVI did not differ between groups treated with different therapeutic approaches.

Pulmonary vein isolation (PVI) is the gold-standard treatment for rhythm control in atrial fibrillation (AF). Cryoballoon (CB) technology is a single-shot technology with established superiority over drug therapy for paroxysmal AF (PAF)¹. By providing two different balloon dimensions (28 and 31 mm), novel resizable CB may improve the effectiveness of pulmonary vein isolation². This study compares a new resizable CB with the fixed-size 28 mm CB. To evaluate the non-inferiority of the resizable POLARx FIT cryoballoon compared to fixed-size Arctic Front Advance Pro cryoballoon. This two-center randomized controlled trial so far enrolled 155 PAF patients with indication for PVI, assigning them in a 1:1 ratio to either the Medtronic 4th generation fixed-size CB (Arctic Front Advance Pro) or the Boston Scientific resizable CB (POLARx FIT). Follow-ups include clinic visits and 24-hour ECG recordings at 3, 6, and 12 months, with additional visits every six months. Among the 155 recruited patients (75 in the Polar group, 80 in the Arctic group), 64 (41.3%) were female, with an average age of 60.4 ± 12.1 years. Groups were similar regarding sex and age. Procedure duration in the Polar group was 67.0 ± 20.2 min compared to 63.5 ± 20.2 min in the Arctic group (p=0.27). Fluoroscopy times and dose area products were comparable as well, with 8.3 ± 7.0 min and 742 ± 753 mcGym² in the Polar group and 7.9 ± 7.1 min and 617 ± 1016 mcGym² in the Arctic group (respectively p = 0.69 and p = 0.39). Complete PVI was achieved in 98.7% of Polar cases and 96.3% of Arctic cases (p=0.36). The Polar group exhibited somewhat higher incidence of impending or transient phrenic nerve palsy (5 cases) compared to the Arctic group (2 cases, p = 0.22). There was one Polar patient who developed effusive pericarditis. Vascular complications were detected in 3 Polar patients (arteriovenous fistula ± pseudoaneurysm) and one Arctic patient (arteriovenous fistula with pseudoaneurysm). No other complications were noted. The differences between the groups were not statistically significant. In our study, the new resizable POLARx FIT cryoballoon was equivalent to the Arctic Front Advance Pro CB regarding procedure duration, fluoroscopy time, radiation dose, and acute PVI success. Only complications related to venous access were reported. Ongoing follow-up is essential to establish non-inferiority in terms of long-term outcomes.

Premature ventricular complexes (PVCs) are only clinically significant in a small number of patients. Symptoms are usually accompanied by a significant PVCs burden, which can then cause cardiomyopathy in the long term. Catheter ablation is the therapy of choice in these situations. One of the most challenging foci is the area of the so-called left ventricular summit (LV summit), due to close anatomical connections and consequently a greater possibility of periprocedural complications, including injuries of coronary arteries. We report the case of a patient with atypical chest pain and an acute thrombotic occlusion of the ostial level of the left circumflex artery after a PVCs ablation in the LV summit. An urgent coronary angiography was performed via the right transradial approach and PCI was performed with the implantation of one drug-eluting stent. This case report suggests that it should be standard practice to record a 12-channel ECG of every patient immediately after returning to the ward, regardless of the existence of any symptoms. Considering the low risk of diagnostic coronary angiography (< 1%), we believe that it should be routinely done before and after the planned ablation in the area of the LV summit.

Chronic inflammation plays a role in heart failure (HF) progression across its subtypes (reduced, mildly reduced, and preserved ejection fraction (EF) (1). While C-reactive protein (CRP) and albumin are known prognostic markers (2), the potential of the CRP-to-albumin ratio (CAR) and red blood cell distribution width-to-albumin ratio (RAR) as prognostic indicators in HF remains underexplored. This prospective observational study was conducted at a tertiary hospital centre, enrolling HF patients between May 2021 and March 2024. Data on demographics, comorbidities, serum biomarkers, EF, and adverse events (death, HF-related emergencies, or hospitalizations) were collected. Patients with complete CRP and albumin measurements at baseline and 6-month follow-up were included. Among 1170 hospitalized HF patients, 368 were included. The median age was 67 years (IQR 60-74), 30% females (Figure 1). Over the 6-month follow-up, CAR significantly decreased from 0.12 (95% CI 0.106-0.147) to 0.063 (95% CI 0.056-0.071), p<0.0001, with no significant difference between empagliflozin and dapagliflozin groups (p=0.922). There were 40 HF composite events. CAR and RAR were both correlated with HF composite events (CAR: r= 0.163, p= 0.0017; RAR: r= 0.157, p= 0.0025), particularly in the HFpEF group (CAR: r= 0.32, p= 0.0032; RAR: r= 0.307, p= 0.0047). SGLT2i significantly reduced CAR over the 6-month follow-up period, irrespective of the specific SGLT2i agent. Both CAR and RAR were independently associated with adverse HF outcomes, particularly in the HFpEF cohort, highlighting the significance of inflammatory processes in HF and the potential role of SGLT2i in modulating these markers in clinical practice.Baseline characteristics of participants

BACKGROUND:Artificial intelligence (AI) and large language models (LLMs), such as OpenAI's GPT-4, are increasingly being explored for medical applications. Recently, GPT-4 gained image processing capabilities, enabling it to handle tasks such as image captioning, visual question answering, and potentially interpreting medical data. Despite promising potential in diagnostics, the effectiveness of GPT-4 in interpreting complex 12-lead electrocardiograms (ECGs) remains to be assessed. METHODS:This study utilized GPT-4 to interpret 150 12-lead ECGs from the Cardiology Research Dubrava (CaRD) registry, spanning a wide range of cardiac pathologies. The ECGs were classified into 4 categories for analysis: arrhythmias, conduction system abnormalities, acute coronary syndrome, and other. Two experiments were conducted: one where GPT-4 interpreted ECGs without clinical context, and another with added clinical scenarios. A panel of experienced cardiologists evaluated the accuracy of GPT-4's interpretations. RESULTS:In this cross-sectional observational study, GPT-4 demonstrated a correct interpretation rate of 19% without clinical context and a significantly improved rate of 45% with context (P < 0.001). The addition of clinical scenarios significantly enhanced interpretative accuracy, particularly in the acute coronary syndrome category (10% vs 70%; P < 0.0.01). The "other" category showed no impact (51% vs 59%; P = 0.640), and trends toward significance were observed in the arrhythmias (9.7% vs 32%; P = 0.059) and conduction system abnormalities (4.8% vs 19%; P = 0.088) categories when given clinical context. CONCLUSIONS:Although GPT-4 shows potential in aiding 12-lead ECG interpretation, its effectiveness varies significantly with clinical context. The study suggests that GPT-4 alone in its current form may not provide accurate 12-lead ECG interpretation.

Beta-blockers (BBs) have proven their efficacy in reducing mortality in patients with heart failure (HF) with reduced ejection fraction (HFrEF). However, the effects in patients with heart failure with preserved ejection fraction (HFpEF) and heart failure with mildly reduced ejection faction (HFmrEF) are less clear and consistent data are lacking. The aim of this study was to examine the association of BB therapy with all-cause mortality in different groups of HF patients. We investigated BB use in real-life cohort of patients with HF diagnosis included in the registry in the period between June 2021 and February 2024. We compared all-cause mortality between patients who did not receive any BB therapy and patients receiving BB therapy at three different doses, defined as maximal, medium (≥50% of maximal dose) and low (≥25% of maximal dose). For statistical analysis we used chi-square and Fisher’s exact test and the p value of 0.05 was defined as statistically significant. This registry-based study included 1009 patients with median age of 70 years (IQR 62-76), and median follow-up period of 365 days (IQR 184-367). Total of 247 patients had HFpEF (24.5%), 146 patients had HFmrEF (14.5%) and 616 patients had HFrEF (61.1%). In HFrEF group patients with BB therapy in any dose had significantly lower all-cause mortality compared to the patients without BB therapy (p=.02). In both HFmrEF and HFpEF group of patients BB therapy had no influence on all-cause mortality. There was no statistically significant difference in dose-related outcomes for three different BB doses in overall HF cohort, nor in each HF group separately. BB use in HFrEF patients with history of AF was associated with significantly lower all-cause mortality (p<.00001), but these results did not translate to HFpEF nor HFmrEF patients with history of AF. Our findings indicate that BB do not improve survival in patients with HFmrEF and HFpEF, independently of history of AF. Real-life studies and well-designed registries with larger cohorts of patients and longer follow-up period are needed to investigate the impact of BB use and dosing on survival in different groups of HF patients.

Pulsed field ablation (PFA) has emerged as an innovative technique for treating atrial fibrillation (AFib), utilizing electric fields to selectively ablate cardiac tissue while minimizing damage to surrounding structures. Different PFA systems may result in varying levels of biomarker release and haemolysis, potentially impacting procedural outcomes and patient safety. The aim of the study is to evaluate the initial findings on biomarker release and haemolysis among 3 different PFA systems. This prospective, randomized study including patients undergoing pulmonary vein isolation due to paroxysmal and persistent AFib, compared 3 PFA systems: Varipulse (Group V, N=8), Pulseselect (Group P, N=10), and Farapulse (Group F, N=12) focusing on the release of biomarkers associated with myocardial injury (high-sensitive troponin T (hs-cTnT), myoglobin), inflammatory response (C-reactive protein [CRP]), and indicators of haemolysis (haemoglobin, bilirubin, lactate dehydrogenase (LDH)). Biomarker levels were measured before the procedure, 4 and 24 hours after. In all 3 groups the ablation was done according to the companies' recommended protocols regarding the number of PFA applications. The mean age in the study population was 58 ±12 years, 50% paroxysmal AFib. After 24 hours haemoglobin levels significantly decreased in Group V (-6.0%), Group P (-6.9%), and Group F (-10.5%), without significant difference between groups (p= 0.342). Bilirubin levels increased significantly in all 3 groups (Group V 15.4% vs Group P 5.3% vs. Group F 58.3%), with Group F showing a significantly larger increase (p= 0.020). LDH levels increased significantly in Group P (50.6%) and Group F (38.6%) compared to Group V (27.6%) (p= 0.038). CRP levels increased significantly by 60% in Group V, 189.6% in Group P, and 385.2% in Group F, without significant differences between groups (p= 0.920). Myoglobin levels increased significantly in all groups (V 76.7% vs. P 56.1% vs. F 38.9%), without significant differences between the groups (p= 0.732). Hs-cTnT levels increased significantly in all groups (V 93337% vs. P 235080% vs. F 244780%), without significant differences between groups (p= 0.128). The choice of PFA system has some impact on biomarker release and haemolysis levels. Farapulse (Group F) demonstrated the highest increases in bilirubin and CRP levels, indicating a greater inflammatory response and haemolytic effect. Further studies are needed to explore both short- and long-term implications of these differences in clinical practice.

AIMS:Indications and clinical impact of genetic testing for cardiac diseases have increased significantly over the past years. The aim of this physician-based European Heart Rhythm Association (EHRA) survey was to assess current clinical practice and access to genetic testing for cardiac diseases across European Society of Cardiology countries and to evaluate adherence to the 2022 EHRA/HRS/APHRS/LAHRS Expert Consensus Statement on genetic testing. METHODS AND RESULTS:An online questionnaire composed of 28 questions was submitted to the EHRA Research Network and European Reference Network GUARD-Heart healthcare partners and promoted via dedicated social media channels. There were 357 respondents from 69 countries, 40% working in a hospital setting with a cardiac genetic service and/or a dedicated clinic focusing on inherited cardiac diseases and 27% with an onsite genetic laboratory. No genetic testing or low annual rate (<10/year) was declared by 39% of respondents. The majority of respondents (78%) declared issues or limitations to genetic testing access in their clinical practice. The main reasons for not providing or limited access to genetic testing were no availability of dedicated unit or genetic laboratory (35%) or reimbursement issues (25%). The most frequently reported indication for genetic testing was diagnostic purpose (55%). Most respondents (92%) declared offering genetic testing preceded by genetic counselling and 42% regular multidisciplinary evaluations for patients with cardiac genetic diseases. The perceived value of genetic testing in the diagnostic, prognostic, and therapeutic assessment was variable (67, 39, and 29%, respectively) and primarily based on the specific inherited disease. The majority of respondents recommended cascade genetic testing for the first-degree family members in case of pathogenic/likely pathogenic variant in the proband. CONCLUSION:This survey highlights a significant heterogeneity of genetic testing access and provision and issues attributable to the availability of dedicated unit/genetic laboratory and reimbursement. However, adequate adherence to indications in the current recommendations for genetic testing in patients with cardiac diseases was observed.

Introduction Ventricular tachycardia (VT) poses a significant challenge in patients with both ischemic and non-ischemic cardiomyopathy, requiring precise localization of VT exit sites for effective ablation. The use of preprocedural image-based substrate reconstruction with inHEART software has become integral in identifying scar and fibrosis patterns that correlate with VT exit sites. This study examines the correlation between inHEART-based imaging and the actual ablation zones in patients with ischemic versus non-ischemic cardiomyopathy. Methods and patients This retrospective analysis included 40 patients (mean age 50 ±25, female: 5 (N)) undergoing VT ablation. Out of the 40 patients, 31 had ischemic cardiomyopathy and 9 had non-ischemic cardiomyopathy. Preprocedural imaging (computed tomography (CT)), was processed using inHEART software to reconstruct myocardial substrates and identify potential VT exit sites. These predicted exit sites were then compared with the actual ablation zones to assess the accuracy of the inHEART-based substrate reconstructions. Results The ablations were executed utilizing a 3D mapping system CARTO after merging with the inHEART model. In 6 patients, all from the non-ischemic cardiomyopathy group, the predicted VT exit zones based on inHEART imaging did not correlate with the areas targeted during ablation. Discussion The study underscores the effectiveness of inHEART software for preprocedural planning in ischemic cardiomyopathy, where scar patterns are typically well-defined and align closely with VT exit sites. However, the lack of correlation in non-ischemic cardiomyopathy patients highlights the complexity of diffuse fibrosis and other substrate characteristics that may not be fully captured by imaging alone. These findings suggest the need for further refinement in imaging protocols and possibly integrating functional mapping to enhance ablation strategies for non-ischemic cardiomyopathy.

Abstract Introduction Dyslipidaemia is an important correctable risk factor for coronary artery disease (CAD). Many studies have confirmed that the lower the low-density lipoprotein cholesterol (LDL-C) levels are, the lower is the CAD morbidity and mortality rates (1). However, many patients who achieved low levels of LDL-C still experience a major adverse cardiovascular event (MACE) because of the other residual risk factors. Therefore, there is a constant need for better stratification of patients who are at higher risk for novel MACE following their first acute coronary syndrome (ACS). Evidence increasingly suggests that the ratio of LDL-C/HDL-C might be a new and better marker of cardiovascular disease, as it simultaneously evaluates the levels of both LDL-C and HDL-C (2). Purpose The aim of this study was to investigate the prediction value of LDL-C/HDL-C ratio for long term prognosis after ACS as well as its correlation with CAD severity. Methods We included patients hospitalized at out centre with ACS from January 2017 to January 2024. Demographic data, data on LDL-C and HDL-C levels on admission and calculated Syntax score were used. Syntax score is a comprehensive angiographic scoring system which determines complexity by using coronary anatomy and lesion characteristics (3). Follow-up data were collected either by clinical follow-up visits or by telephone interviews. The MACE was defined as the composite of cardiovascular death, acute coronary syndrome and need for elective or urgent percutaneous or surgical revascularization. Results This registry-based study included 2471 patients with ACS, median age of 64 (interquartile range 56-73) years, 31% female. Total of 1099 patients (44%) had non-ST elevation ACS and 1372 (54%) had ST elevation myocardial infarction (STEMI). Median Syntax score was 13 (IQR 7-20.5), with 1494 (61%) patients having low Syntax score (≤16), 508 (21%) patients medium (16-22), and 448 (18%) high score (>22), respectively. Median follow up was 17 (3-27) months. LDL-C/HDL-C ratio correlated significantly with cardiovascular death, with weak coefficient (2.94 vs. 2.54 p<0.001; rho=0.102, p<.0001), however did not correlate with MACE (2.88 vs. 2.92, p=0.188, rho=0.06, p=0.77). This remained identical when tested for patients with STEMI and non-STE ACS. In addition, LDL-C/HDL-C ratio did not correlate with CAD severity as assessed with Syntax score (low 2.92 vs. medium 2.83 vs. high 2.86, p=0.597; rho=0.4, p=0.09). Conclusion Our data suggest that LDL-C/HDL-C ratio cannot be used as a relevant predictor of post-ACS long-term MACE or cardiovascular death, nor it can be correlated with CAD severity. Further studies are needed to establish the real value of LDL-C/HDL-C ratio as a post-ACS predictor.