The incidence of atrial fibrillation (AF) in patients with ST segment elevation myocardial infarction (STEMI) varies between 7% and 21%, and most of these studies were in the thrombolytic era. However, the frequency of new-onset AF during the primary percutaneous coronary intervention (PCI) period is still unclear. We aimed to investigate the frequency of new-onset AF and its effects on long-term clinical events in patients undergoing primary PCI. A total of 1,603 patients who were diagnosed with STEMI and underwent primary PCI were included in the study. All the patients were monitored for at least 48 hours after the procedure. The primary endpoint of the study was defined as new-onset AF during hospitalization. The median follow-up period of our study was 44 months. New-onset AF developed in 85 (6.1%) patients. CHADs-VASc > 2, KILLIP > 2, and left atrial diameter were found to be independent predictors for the development of new-onset AF. In the AF (+) group, the all-cause and in-hospital mortality rates were found to be significantly higher. New-onset AF development in patients with STEMI was detected as an independent predictor of in-hospital mortality. In the era of primary percutaneous transluminal coronary angioplasty, new-onset AF rates were found to be lower than the literature data. In addition, new-onset AF was found to be a predictor of in-hospital mortality, and deaths occurred mostly in the early period. Therefore, close follow-up of these patients in the early period and re-evaluation in terms of AF burden when the patient becomes stable are important.

Background/Objectives: Inflammation contributes to atherosclerotic progression and may intensify after percutaneous coronary intervention (PCI). In stable coronary artery disease (CAD), whether post-procedural inflammation is prognostically distinct from baseline inflammatory status and post-procedural renal function remains unclear. Methods: We studied 496 consecutive patients with stable CAD undergoing elective PCI. The primary outcome was a composite of death, myocardial infarction, stroke, or repeat revascularization. Post-PCI high-sensitivity C-reactive protein (hs-CRP) and creatinine were measured 18–24 h after PCI. Multivariable Cox models used clinically prespecified covariates, with hs-CRP log-transformed (hazard ratio [HR] per doubling) and additionally adjusted for its pre-PCI level; discrimination was assessed by ROC analysis with bootstrap internal validation. Results: The endpoint occurred in 43 patients (8.7%) over a median follow-up of 10 months. Post-PCI hs-CRP was independently associated with the endpoint after adjustment for pre-PCI hs-CRP, post-PCI creatinine, and albumin (HR 1.43 per doubling, 95% CI 1.05–1.96, p = 0.025), and after further adjustment for angiographic and procedural characteristics (HR 1.54, p = 0.008); pre-PCI hs-CRP was not independent (p = 0.083). Post-PCI creatinine was independently associated in every model (HR 1.16 per 0.1 mg/dL, p = 0.001) and identified a largely non-overlapping high-risk group. Conclusions: After elective PCI in stable CAD, post-PCI hs-CRP was independently associated with adverse outcomes and provided prognostic information beyond baseline hs-CRP and procedural characteristics in the fitted models, rather than merely reflecting baseline inflammatory status. Post-PCI renal function was a complementary, largely independent risk signal.

New-onset atrial fibrillation (NOAF) is a frequent complication among patients with non-ST-elevation myocardial infarction (NSTEMI) and is associated with adverse outcomes, making early identification of predictors essential for risk stratification and management. This retrospective cohort study evaluated the prognostic value of the Clinical SYNTAX score (CSS) compared with the anatomical SYNTAX score (SS), GRACE, and CHA2DS2-VASc scores in predicting in-hospital NOAF and long-term outcomes among 979 NSTEMI patients undergoing coronary angiography. Predictors of NOAF, all-cause mortality, and major adverse cardiovascular events (MACEs: death, myocardial infarction, stroke) were identified using logistic and Cox regression models, with receiver operating characteristic (ROC) analysis used to compare the discriminative power of CSS against SS, GRACE, and CHA2DS2-VASc over a median follow-up of 86 months (IQR 36–100; range 0.1–144). NOAF developed in 80 patients (8.2%), with age, female gender, left atrial diameter, left ventricular diastolic dysfunction, and CSS (p = 0.014) identified as independent predictors. CSS’s AUC for predicting NOAF (0.724; 95% CI: 0.673–0.775) was significantly higher than SS’s (0.644; 95% CI: 0.588–0.699; DeLong p < 0.001) and comparable to that of the CHA2DS2-VASc and GRACE scores; a CSS threshold ≥ 17.77 predicted NOAF with 75% sensitivity and 65% specificity. In Cox regression analysis, in-hospital NOAF, age, hypertension, reduced ejection fraction (<60%), and CSS independently predicted long-term all-cause mortality, while NOAF, EF < 60%, age, early AF recurrence, hypertension, and CSS independently predicted MACEs; SS was not a significant predictor in either model. In non-overlapping multivariable models, this advantage reflected the contribution of CSS’s clinical components rather than incremental value of the composite score; CSS nonetheless remained an independent predictor of NOAF and long-term outcomes and may serve as a practical single-score tool for risk-guided management.

New-onset atrial fibrillation (NOAF) is a frequent complication among patients with non-ST-elevation myocardial infarction (NSTEMI) and is associated with adverse outcomes, making early identification of predictors essential for risk stratification and management. This retrospective cohort study evaluated the prognostic value of the Clinical SYNTAX Score (CSS) compared with the anatomical SYNTAX Score (SS), GRACE, and CHA2DS2-VASc scores in predicting in-hospital NOAF and long-term outcomes among 979 NSTEMI patients undergoing coronary angiography. Predictors of NOAF, all-cause mortality, and major adverse cardiovascular events (MACE: death, myocardial infarction, stroke) were identified using logistic and Cox regression models, with receiver operating characteristic (ROC) analysis used to compare the discriminative power of CSS against SS, GRACE, and CHA2DS2-VASc over a median follow-up of 86 months (IQR: 0.1–144). NOAF developed in 80 patients (8.2%), with age, female gender, left atrial diameter, left ventricular diastolic dysfunction, and CSS (p=0.014) identified as independent predictors. CSS demonstrated superior discriminative ability (AUC: 0.724; 95% CI: 0.673–0.775) compared with SS (AUC: 0.644; 95% CI: 0.588–0.699), and a CSS threshold ≥17.77 predicted NOAF with 75% sensitivity and 65% specificity. In Cox regression analysis, in-hospital NOAF, age, hypertension, reduced ejection fraction (<60%), and CSS independently predicted long-term all-cause mortality, while NOAF, EF<60%, age, early AF recurrence, hypertension, and CSS independently predicted MACE; SS was not a significant predictor in either model. These findings indicate that CSS outperforms SS in predicting in-hospital NOAF and long-term outcomes in NSTEMI patients, offering a practical and comprehensive tool for early rhythm monitoring and risk-guided management.