Application of artificial intelligence in the diagnosis and treatment of cardiac arrhythmia.

The rapid growth in computational power, sensor technology, and wearable devices has provided a solid foundation for all aspects of cardiac arrhythmia care. Artificial intelligence (AI) has been instrumental in bringing about significant changes in the prevention, risk assessment, diagnosis, and treatment of arrhythmia. This review examines the current state of AI in the diagnosis and treatment of atrial fibrillation, supraventricular arrhythmia, ventricular arrhythmia, hereditary channelopathies, and cardiac pacing. Furthermore, ChatGPT, which has gained attention recently, is addressed in this paper along with its potential applications in the field of arrhythmia. Additionally, the accuracy of arrhythmia diagnosis can be improved by identifying electrode misplacement or erroneous swapping of electrode position using AI. Remote monitoring has expanded greatly due to the emergence of contactless monitoring technology as wearable devices continue to develop and flourish. Parallel advances in AI computing power, ChatGPT, availability of large data sets, and more have greatly expanded applications in arrhythmia diagnosis, risk assessment, and treatment. More precise algorithms based on big data, personalized risk assessment, telemedicine and mobile health, smart hardware and wearables, and the exploration of rare or complex types of arrhythmia are the future direction.

Efficacy and safety of cilostazol-based triple antiplatelet therapy compared with clopidogrel-based dual antiplatelet therapy in patients with acute ST-elevation myocardial infarction undergoing percutaneous coronary intervention: A multicenter, randomized, open-label, phase 4 trial.

BACKGROUND: Previous studies reported that compared to conventional dual antiplatelet therapy (DAT; aspirin + clopidogrel), triple antiplatelet therapy (TAT), involving the addition of cilostazol to DAT, had better clinical outcomes in patients with ST-elevation myocardial infarction (STEMI). However, the optimal duration of TAT is yet to be determined. METHODS: In total, 985 patients with STEMI who underwent primary percutaneous coronary intervention (PCI) with drug-eluting stents (DESs) were prospectively enrolled in 15 PCI centers in South Korea and China. We randomly assigned patients into 3 groups: DAT (aspirin and clopidogrel for 12 months), TAT 1M (aspirin, clopidogrel, and cilostazol for 1 month), and TAT 6M (aspirin, clopidogrel, and cilostazol for 6 months). The primary endpoint was 1-year major adverse cardiovascular events (MACEs), defined as a composite of all-cause death, recurrent myocardial infarction, stroke, or repeat revascularization. RESULTS: The primary endpoint did not differ among the 3 groups (8.8% in DAT, 11.0% in TAT 1M, and 11.6% in TAT 6M; hazard ratio for TAT 1M vs DAT, 1.302; 95% confidence interval [CI], 0.792-2.141; P = .297; hazard ratio for TAT 6M vs DAT, 1.358; 95% CI, 0.829-2.225; P = .225). With respect to in-hospital outcomes, more bleeding events occurred in the TAT group than in the DAT group (1.3% vs 4.7% vs 2.6%, P = .029), with no significant differences in major bleeding events. Additionally, the TAT group had a higher incidence of headaches (0% vs 1.6% vs 2.6%, P = .020). CONCLUSIONS: The addition of cilostazol to DAT did not reduce the incidence of 1-year MACEs compared with DAT alone. Instead, it may be associated with an increased risk of drug intolerance and side effects, including in-hospital bleeding and headaches.

Machine Learning in Cardio-Oncology: New Insights from an Emerging Discipline.

A growing body of evidence on a wide spectrum of adverse cardiac events following oncologic therapies has led to the emergence of cardio-oncology as an increasingly relevant interdisciplinary specialty. This also calls for better risk-stratification for patients undergoing cancer treatment. Machine learning (ML), a popular branch discipline of artificial intelligence that tackles complex big data problems by identifying interaction patterns among variables, has seen increasing usage in cardio-oncology studies for risk stratification. The objective of this comprehensive review is to outline the application of ML approaches in cardio-oncology, including deep learning, artificial neural networks, random forest and summarize the cardiotoxicity identified by ML. The current literature shows that ML has been applied for the prediction, diagnosis and treatment of cardiotoxicity in cancer patients. In addition, role of ML in gender and racial disparities for cardiac outcomes and potential future directions of cardio-oncology are discussed. It is essential to establish dedicated multidisciplinary teams in the hospital and educate medical professionals to become familiar and proficient in ML in the future.

Combination of SVI/S' and diagnostic scores for heart failure with preserved ejection fraction.

The diagnosis of heart failure with preserved ejection fraction (HFpEF) remains a challenge. There are three methods proposed as diagnostic tools. H2 FPEF score was determined by six weighted clinical characteristics and echocardiographic variables. Heart Failure Association (HFA)-PEFF algorithm consists of various functional and morphological variables as well as natriuretic peptides. SVI/S' is a novel echocardiographic parameter calculated by stroke volume index and mitral annulus systolic peak velocity. This study aimed to compare the three approaches in patients with suspected HFpEF. Patients referred to right heart catheterization for suspected HFpEF were classified into low-, intermediate- and high-likelihood groups according to H2 FPEF or HFA-PEFF scores. A diagnosis of HFpEF was confirmed by pulmonary capillary wedge pressure (PCWP) of ≥15 mm Hg according to the guidelines. In result, a total of 128 patients were included. Of these, 71 patients with PCWP ≥15 mm Hg and 57 patients with PCWP <15 mm Hg. Moderate correlations were observed between H2 FPEF score, HFA-PEFF score, SVI/S' and PCWP. The area under curve of SVI/S' was 0.82 for diagnosis of HFpEF, compared with 0.67 for H2 FPEF score and 0.75 for HFA-PEFF score by receiver-operating characteristics analysis. Combining SVI/S' with diagnostic scores showed higher Youden index and accuracy than each score alone. Kaplan-Meier analysis reported that the high-likelihood group showed poorer outcomes regardless the method used for diagnosis. Among the contemporary tools for identifying HFpEF in this study, the combination of SVI/S' with risk scores showed best diagnostic ability. Each of the strategies can determine rehospitalisation because of heart failure.

Imaging investigation of cervicocranial artery dissection by using high resolution magnetic resonance VWI and MRA: qualitative and quantitative analysis at different stages.

BACKGROUND: To explore the value of magnetic resonance angiography (MRA) and high resolution magnetic resonance vessel wall imaging (HRMR-VWI) in cervicocranial artery dissection (CCAD) for the disease diagnosis, course staging and treatment. On the basis of qualitative evaluation, this study also extract the changes of different stages in vessel wall in different vessel segments to identify imaging indicators for the quantitative evaluation of CCAD. METHODS: We retrospectively enrolled 34 patients with CCAD (38branches) with conventional MRA and HRMR-VWI examinations. Two radiologists independently analyzed imaging features of vessel wall and lumen in the different stages, and the typical sign detection of artery dissection were compared between MRA and HRMR-VWI. Then the parameters of vessel wall was quantitatively evaluated by the post-processing software (Vesselmass, Leiden University Medical Center, Leiden, The Netherlands. RESULTS: HRMR-VWI revealed typical sign detection of artery dissection in all patients in the acute and subacute stage. Among them, the intimal flap/double lumen sign ditection were more common than the MRA, there was significant difference (P = 0.012). MRA revealed typical sign detection of artery dissection in more than half the patients, and the detection was no significant difference at the chronic stage between MRA and HRMR-VWI (P = 1.000/1.000/0.761). In the acute and subacute stage, the typical sign detection of intramural hematoma and Grade II enhancement revealed by HR-MRI was higher than the observations in the chronic stage (P = 0.000/0.000/0.016), while there was no significant difference by MRA (P = 0.902). The values of wall thickness, relative signal intensity of vessel wall enhancement, relative signal intensity of intramural hematoma (IMH), and percentage of stenosis in CCAD decreased from acute to subacute and then to chronic stages. Each quantitative parameter in patients with CCAD in the early stages (i.e., acute and subacute stages) was significantly different from that in patients with CCAD in the recovered group at chronic stage (P < 0.05). Wall thickness and relative signal intensity of vessel wall enhancement in patients with CCAD in the early stages were not significantly different from those in patients with CCAD in the incompletely recovered group at chronic stage (P > 0.05). CONCLUSIONS: As the only noninvasive imaging technology, HRMR-VWI displays the structure of the vessel wall in vivo, showing not only excellent performance in the early diagnosis of CCAD, but also describing the changes of different stages in the qualitative and quantitative characteristics of vessel wall. It also helps to guide the diseasediagnosis, course staging and treatment of CCAD. Although the diagnostic efficacy of MRA was not as good as HRMR-VWI, it should be the first choice of method for routine examination in evaluating CCAD, especially at the chronic stage of CCAD.

Impact of automatic acquisition of key clinical information on the accuracy of electrocardiogram interpretation: a cross-sectional study.

BACKGROUND: The accuracy of electrocardiogram (ECG) interpretation by doctors are affected by the available clinical information. However, having a complete set of clinical details before making a diagnosis is very difficult in the clinical setting especially in the early stages of the admission process. Therefore, we developed an artificial intelligence-assisted ECG diagnostic system (AI-ECG) using natural language processing to provide screened key clinical information during ECG interpretation. METHODS: Doctors with varying levels of training were asked to make diagnoses from 50 ECGs using a common ECG diagnosis system that does not contain clinical information. After a two-week-blanking period, the same set of ECGs was reinterpreted by the same doctors with AI-ECG containing clinical information. Two cardiologists independently provided diagnostic criteria for 50 ECGs, and discrepancies were resolved by consensus or, if necessary, by a third cardiologist. The accuracy of ECG interpretation was assessed, with each response scored as correct/partially correct = 1 or incorrect = 0. RESULTS: The mean accuracy of ECG interpretation was 30.2% and 36.2% with the common ECG system and AI-ECG system, respectively. Compared to the unaided ECG system, the accuracy of interpretation was significantly improved with the AI-ECG system (P for paired t-test = 0.002). For senior doctors, no improvement was found in ECG interpretation accuracy, while an AI-ECG system was associated with 27% higher mean scores (24.3 ± 9.4% vs. 30.9 ± 10.6%, P = 0.005) for junior doctors. CONCLUSION: Intelligently screened key clinical information could improve the accuracy of ECG interpretation by doctors, especially for junior doctors.

CD36+/CD61+ Microparticles Correlate with the Risk of Percutaneous Cardiac Interventions in Coronary Artery Disease Patients and the Effects of Ticagrelor.

PURPOSE: The CD36 scavenger receptor is a mediator of both atherogenesis and thrombosis. We aimed to investigate the prognostic value of CD36+ microparticles (MPs) released from platelets for cardiovascular event presentation in coronary artery disease (CAD) patients and the effects of different antiplatelet drugs on MPs. METHODS: A total of 101 aspirin-treated CAD patients, who were planned to undergo coronary angiography (CAG), were randomized to either a standard clopidogrel regimen or ticagrelor treatment. Total Annexin V-(AV)+ MPs, CD61+/AV+ MPs, and CD36+/CD61+/AV+ MPs were quantified by flow cytometry at baseline, before and immediately after the operation. The ADP-induced platelet inhibition rate was measured by thromboelastogram (TEG) examination 1 h before the operation. RESULTS: The baseline levels of CD36+/CD61+/AV+ MPs were significantly increased in percutaneous coronary intervention (PCI) patients (n = 52) compared to no-PCI patients (n = 49) (p < 0.05). A ROC-curve clustered model for CD36+/CD61+/AV+ MPs at baseline predicted an increased risk of PCI [p = 0.009, AUC = 0.761 (95%CI: 0.601 to 0.922)]. Moreover, TEG examination showed that the preoperative proportion of CD36+/CD61+/AV+ MPs was significantly negatively correlated with R time and K time (r = - 0.236, p = 00.026; r = - 0.288, p = 0.006), and positively correlated with MAADP (r = 0.226, p = 0.045). Subgroup analysis of PCI group showed that the platelet inhibition rate of ticagrelor was significantly higher (66.05% ± 28.76% vs.31.01% ± 27.33%, p < 0.001), and the number of AV+ MPs, CD61+/AV+ MPs, and CD36+/CD61+/AV+ MPs before the operation was significantly lower than clopidogrel (p < 0.05, all). CONCLUSION: The high levels of CD36+ MPs derived from activated platelets are related to an increased risk of PCI in CAD patients. Ticagrelor significantly reduced the number of CD61+/AV+ MPs and CD36+/CD61+/AV+ MPs. This trial registration number is ChiCTR1800014908 and the date of registration is 2018.05.01.

Comparison of Different Hydration Strategies in Patients with Very Low-Risk Profiles of Contrast-Induced Nephropathy.

BACKGROUND Hydration remains the mainstay of contrast-induced nephropathy (CIN) prevention, and new biomarkers of cystatin C (Cys C) and neutrophil gelatinase-associated lipocalin (NGAL) have been suggested. This study aimed to explore whether hydration is essential in patients with very low-risk profiles of CIN who are undergoing coronary angiography. MATERIAL AND METHODS A total of 150 patients were enrolled and randomly distributed to 3 groups: the Preventive Group (n=50, saline hydration was given 6 h before the procedure until 12 h after the procedure), the Remedial Group (n=50, saline hydration was given after procedure for 12 h), and the No Hydration (NH) group (n=50, saline was only given during the procedure). Serum creatinine (Cr), Cys C, and urinary NGAL were tested 3 times at different times. RESULTS Six patients were excluded because of Mehran risk score >2. There was no CIN among 144 individuals. At 24 h and at 72 h after the procedure, we found no significant differences in the levels of Cr and Cys C (0.72±0.11 mg/L for the Preventive Group, 0.67±0.14 mg/L for the Remedial Group, and 0.70±0.1 6 mg/L for the NH Group) among the 3 groups. Urinary NGAL also did not differ significantly among the 3 groups at 6 h or at 48 h (6.31±6.60 ng/ml for the Preventive Group, 5.00±5.86 ng/ml for the Remedial Group, and 6.97±6.37 ng/ml for the NH Group) after the procedure. Subgroup analysis in patients who underwent percutaneous coronary intervention (PCI) showed that there was no significant difference in serum Cr, Cys C, or urinary NGAL at different time points among the 3 groups. CONCLUSIONS Saline hydration during the perioperative period might be unnecessary in patients with very low-risk profiles of CIN.

Loading doses of ticagrelor versus clopidogrel in preventing periprocedural myocardial infarction in Asian patients with acute coronary syndrome.

BACKGROUND: Periprocedural myocardial infarction is a common complication following percutaneous coronary intervention. The present study was conducted with an aim to compare the safety and efficacy of loading doses of ticagrelor versus clopidogrel in preventing periprocedural myocardial infarction in Asian patients with acute coronary syndrome undergoing elective percutaneous coronary intervention. METHODS: A total of 114 patients with acute coronary syndrome undergoing elective percutaneous coronary intervention were assigned to clopidogrel group (n = 57, the loading and maintenance doses were 300 and 75 mg qd for clopidogrel, and 300 and 100 mg qd for aspirin), or ticagrelor group (n = 57, the loading and maintenance doses were 180 and 90 mg bid for ticagrelor, and 300 and 100 mg qd for aspirin). Cardiac biomarkers were measured before, 8 hours, and 24 hours after percutaneous coronary intervention. The percutaneous coronary intervention-related periprocedural myocardial infarction was defined according to the fourth universal definition of myocardial infarction (2018). RESULTS: The overall incidence of percutaneous coronary intervention-related periprocedural myocardial infarction was 21.1%. The ticagrelor group showed a significantly lower incidence of periprocedural myocardial infarction (12.3% vs 29.8%, p = 0.022) and numerically lower bleeding events (3.5% vs 8.8%, p = 0.242) as compared with clopidogrel group. No patient had major adverse cardiovascular events during the 1-month follow-up. The levels of high-sensitivity C-reactive protein did not differ significantly between the two groups (p > 0.05), indicating that the benefits of ticagrelor were not from its anti-inflammatory effects. Multivariable analysis showed that the use of ticagrelor (odds ratio: 0.50; 95% confidence interval: 0.29-0.87; p = 0.014) and number of stents (odds ratio: 2.75; 95% confidence interval: 1.25-6.06; p = 0.012) were independent predictors of periprocedural myocardial infarction. CONCLUSION: Pretreatment with a loading dose of ticagrelor seems to be superior in reducing the incidence of percutaneous coronary intervention-related periprocedural myocardial infarction in Asian patients with acute coronary syndrome as compared with clopidogrel.

Effects of nicorandil infusion on ECG parameters in patients with unstable angina pectoris and percutaneous coronary intervention.

BACKGROUND: Percutaneous coronary intervention (PCI) is effective in treating patients with acute coronary syndrome (ACS) but is associated with some serious complications. Nicorandil is an anti-anginal agent acting to improve microvascular circulation and to increase coronary blood flow. The objective of this article is to evaluate the effects of intracoronary injection followed with continuous intravenous injection of nicorandil on ECG parameters in patients with unstable angina pectoris (UA) undergoing PCI. METHODS: A single-center, self-controlled clinical trial was conducted at the Second Hospital of Tianjin Medical University between January 2019 and April 2019. Sixty-three consecutive patients with UA who received coronary angiography and selective PCI were enrolled. ECG was recorded and analyzed before and 24 hr after nicorandil infusion. RESULTS: Patients were divided into three groups: control group (n = 23, aged 63.43 ± 12.55 years), short-term, and prolonged use with nicorandil group (n = 20 and 20, aged 66.45 ± 8.06 years and 65.80 ± 9.49 years, respectively). Clinical characteristics and ECG parameters were similar before PCI among three groups (p > .05). In nicorandil treatment groups, intervals of QTd and Tp-e in patients post-PCI were significantly shorter than that in control and pre-PCI (p < .05). CONCLUSIONS: Nicorandil infusion reduces QTd and Tp-e interval in patients with UA. Further studies will be needed to determine whether these electrophysiological changes are associated with a reduction of ventricular arrhythmias and improved outcomes.

Low-dose adjunctive cilostazol in patients with complex lesions undergoing percutaneous coronary intervention.

Patients with complex coronary lesions undergoing percutaneous coronary intervention (PCI) have more major adverse cardiac events (MACE) than do those with simpler cases. Therefore, intensive antiplatelet therapy might be needed in these patients. A total of 127 patients with complex lesions undergoing PCI in the Second Hospital of Tianjin Medical University from October 2012 to April 2014 were randomized to receive either dual (aspirin plus clopidogrel, DAPT, n = 66), or triple antiplatelet therapy (aspirin plus clopidogrel plus cilostazol; TAPT, n = 61). Patients in the TAPT group received low-dose cilostazol (100 mg loading, followed with 50 mg twice per day) for 3-6 months. The primary endpoint was composite MACE. The complex coronary target lesions were defined as at least one of the following: left main disease; severe 3-vessel disease; chronic total occlusion lesions; true bifurcation lesion; ostial lesions; severe calcified lesions; and highly thrombotic lesions. The two groups had similar baseline clinical and angiographic characteristics. One-year clinical outcomes showed that the TAPT group had significantly lower incidences of myocardial infarction (1.6% vs 13.6%, P = 0.018) and MACE (1.6% vs 16.7%, P = 0.004) than DAPT group. The DAPT group had two cases of stent thrombosis, while the TAPT group did not. Furthermore, adjunctive low-dose cilostazol didn't significantly increase the incidence of bleeding events (26.2% vs 19.7%, P = 0.381) regardless of major (4.9% vs 4.5%, P = 0.921) or minor (21.3% vs 15.2%, P = 0.368) bleeding events. In conclusion, low-dose adjunctive cilostazol seems superior to dual antiplatelet therapy in reducing recurrent ischemic events in patients with complex coronary lesions and the two test groups have a similar incidence of bleeding events.

Comparisons of everolimus and Paclitaxel-eluting stents in patients with acute myocardial infarction.

BACKGROUND: It has been established that the newer-generation drug-eluting stent (DES) everolimus-eluting stent (EES) is superior to the first-generation DES paclitaxel-eluting stent (PES). However, the advantages of EES over PES in the setting of acute myocardial infarction (AMI) need to be fully elucidated. METHODS: The present analysis enrolled 2,911 AMI patients receiving PES (n = 1,210) or EES (n = 1,701) in a large-scale, prospective, multicenter Korea Acute Myocardial Infarction Registry (KAMIR). Propensity score matching was used to adjust for baseline biases in clinical and angiographic characteristics, yielding a total of 2,398 patients (1,199 receiving PES and 1,199 receiving EES). Various clinical outcomes at 1 year were compared between the two propensity score matched groups. Target lesion failure (TLF) was defined as the composite of cardiac death, recurrent nonfatal myocardial infarction (Re-MI), or target lesion revascularization (TLR). RESULTS: Baseline clinical and angiographic characteristics were comparable between the two groups after propensity score matching. Clinical outcomes of the propensity score matched patients showed that the rates of in-hospital and 1-year cardiac and all-cause death were similar between the two groups. But patients in the EES group had significantly lower incidences of Re-MI (1.4% vs 2.8%, P = 0.002), TLR (1.2% vs 3.1%, P = 0.001), TLF (6.4% vs 10.2%, P = 0.001), and probable or definite stent thrombosis (0.3% vs 1.8%, P < 0.001) than did those in the PES group. CONCLUSIONS: The present propensity matched analysis suggests that the use of EES in the setting of AMI appears to be superior to PES in reducing TLF, and stent thrombosis.

Role of ERK1/2 and JNK phosphorylation in iodine contrast agent-induced apoptosis in diabetic rat kidneys.

BACKGROUND: The risk of contrast-induced acute kidney injury (CIAKI) is significantly increased in patients with diabetes mellitus. This study aimed to investigate molecular mechanisms of contrast media-induced apoptosis in diabetic rat kidneys, especially the involvement of ERK1/2 and JNK signal pathways. METHODS: Diabetic Sprague-Dawley rats were induced by intraperitoneal injection of streptozotocin. Ten weeks later the normal and diabetic rats were administered high-osmolar contrast media (HOCM; meglumine diatrizoate) or normal saline (10 mL/kg) injection for 2 consecutive days. At 24 h after the operation, the rats were sacrificed, the blood samples were collected for examining serum creatinine and the kidneys were collected for determining the expression of caspase-3 by immunohistochemistry and the expression of Bcl-2, Bax, upstream signal molecule p-JNK, and p-ERK1/2 by western blotting. RESULTS: The serum creatinine was significantly increased in diabetes + contrast media group (DC group) after operation compared with in the diabetic group (D group; 103.89 ± 9.01 µmol/L vs. 71.52 ± 7.03 µmol/L, p < 0.05). While creatinine clearance rate (Ccr) was significantly decreased in DC group after operation (1.49 ± 0.33 mL/min vs. 2.60 ± 0.54 mL/min, p < 0.05). Especially, in the diabetic kidney, the expression of caspase-3 was also significantly increased after intravenous injection of HOCM compared with normal saline. The expression level of upstream signal molecule p-JNK protein was apparently increased, but p-ERK1/2 protein was significantly decreased (both p < 0.05). CONCLUSIONS: The ionic HOCM-induced renal cells apoptosis in diabetic rats through activating the caspase-3 apoptotic pathway, which might be mediated by upstream MAPK (inhibiting p-ERK1/2 expression and promoting p-JNK expression) signal pathways.

Protective effects of aliskiren on atrial ionic remodeling in a canine model of rapid atrial pacing.

PURPOSE: Aliskiren inhibits the activation of the renin-angiotensin system. Here, we investigated the effects of aliskiren on chronic atrial iron remodeling in the experimental canine model of rapid atrial pacing. METHODS: Twenty-eight dogs were assigned to sham (S), control paced (C), paced + aliskiren (10 mg Kg(-1) d(-1), A1), and paced + aliskiren (20 mg Kg(-1) d(-1), A2) groups. Rapid atrial pacing at 500 bpm was maintained for 2 weeks, while group S was not paced. Levels of serum angiotensin-converting enzyme and angiotensin II after pacing were determined by ELISA. Whole-cell patch-clamp technique, western blot, and RT-PCR were applied to assess atrial ionic remodeling. RESULTS: The density of I CaL and I Na currents (pA/pF) was significantly lower in group C compared with group S (I CaL: -4.09 ± 1.46 vs. -6.12 ± 0.58,P < 0.05; I Na: 30.48 ± 6.08 vs. 46.31 ± 4.73, P < 0.05). However, the high dose of aliskiren elevated the density of I CaL and I Na currents compared with group C (I CaL: -6.23 ± 1.35 vs. -4.09 ± 1.46, P < 0.05; I Na: 58.62 ± 16.17 vs. 30.48 ± 6.08, P < 0.01). The relative mRNA and protein expression levels of Cav1.2 and Nav1.5α were downregulated in group C respectively (Cav1.2: 0.46 ± 0.08; Nav1.5α: 0.52 ± 0.08, P < 0.01; Cav1.2: 0.31 ± 0.03; Nav1.5α: 0.41 ± 0.04, P < 0.01;), but were upregulated by aliskiren. CONCLUSIONS: Aliskiren has protective effects on atrial tachycardia-induced atrial ionic remodeling.

Microcirculatory dysfunction in hypertrophic cardiomyopathy with chest pain assessed by angiography-derived microcirculatory resistance.

Chest pain, a common initial symptom in hypertrophic cardiomyopathy (HCM) patients, is closely linked to myocardial ischemia, despite the absence of significant coronary artery stenosis. This study explored microvascular dysfunction in HCM patients by employing angiography-derived microcirculatory resistance (AMR) as a novel tool for comprehensive assessment. This retrospective analysis included HCM patients with chest pain as the primary symptom and control patients without cardiac hypertrophy during the same period. The AMR was computed through angiography, providing a wire-free and adenosine-free index for evaluating microcirculatory function. Propensity score matching ensured balanced demographics between groups. This study also investigated the correlation between the AMR and clinical outcomes by utilizing echocardiography and follow-up data. After matching, 76 HCM patients and 152 controls were analyzed. While there was no significant difference in the incidence of epicardial coronary stenosis, the AMR of three epicardial coronary arteries was markedly greater in HCM patients. The criterion of an AMR ≥ 250 mmHg*s/m was that 65.7% of HCM patients experienced coronary microvascular dysfunction (CMD). Independent risk factors for CMD included increased left ventricular (LV) wall thickness (OR = 1.209, 95% CI 1.013-1.443, p = 0.036). Furthermore, an AMR_LAD ≥ 250 mmHg*s/m had an increased cumulative risk of the endpoint (log-rank p = 0.023) and was an independent risk factor for the endpoint (HR = 11.64, 95% CI 1.13-120.03, p = 0.039), providing valuable prognostic insights.

Atorvastatin, etanercept and the nephrogenic cardiac sympathetic remodeling in chronic renal failure rats.

BACKGROUND: Chronic renal failure (CRF) patients are predisposed to arrhythmias, while the detailed mechanisms are unclear. We hypothesized the chronic inflammatory state of CRF patients may lead to cardiac sympathetic remodeling, increasing the incidence of ventricular arrhythmia (VA) and sudden cardiac death. And explored the role of atorvastatin and etanercept in this process. METHODS: A total of 48 rats were randomly divided into sham operation group (Sham group), CRF group, CRF + atorvastatin group (CRF + statin group), and CRF + etanercept group (CRF + rhTNFR-Fc group). Sympathetic nerve remodeling was assessed by immunofluorescence of growth-associated protein 43 (GAP-43) and tyrosine hydroxylase positive area fraction. Electrophysiological testing was performed to assess the incidence of VA by assessing the ventricular effective refractory period and ventricular fibrillation threshold. The levels of tumor necrosis factor-alpha (TNF-α) and interleukin-1beta were determined by Western blotting and enzyme-linked immunosorbent assay. RESULTS: Echocardiogram showed that compared with the Sham group, left ventricular end-systolic diameter and ventricular weight/body weight ratio were significantly higher in the CRF group. Hematoxylin-eosin and Masson staining indicated that myocardial fibers were broken, disordered, and fibrotic in the CRF group. Western blotting, enzyme-linked immunosorbent assay, immunofluorescence and electrophysiological examination suggested that compared with the Sham group, GAP-43 and TNF-α proteins were significantly upregulated, GAP-43 and tyrosine hydroxylase positive nerve fiber area was increased, and ventricular fibrillation threshold was significantly decreased in the CRF group. The above effects were inhibited in the CRF + statin group and the CRF + rhTNFR-Fc group. CONCLUSIONS: In CRF rats, TNF-α was upregulated, cardiac sympathetic remodeling was more severe, and the nephrogenic cardiac sympathetic remodeling existed. Atorvastatin and etanercept could downregulate the expression of TNF-α or inhibit its activity, thus inhibited the above effects, and reduced the occurrence of VA and sudden cardiac death.

Coronary microvascular dysfunction and myocardial area at risk assessed by cadmium zinc telluride single photon emission computed tomography after primary percutaneous coronary intervention in acute myocardial infarction patients.

Background: A high proportion of coronary microvascular dysfunction (CMD) has been observed in patients with acute myocardial infarction (AMI) who have received primary percutaneous coronary intervention (PCI), which may affect their prognosis. This study used cadmium zinc telluride (CZT) single photon emission computed tomography (SPECT) to evaluate the prevalence and characteristics of CMD and myocardial area at risk (AAR) in AMI patients who had undergone primary PCI. Methods: We conducted a single-center cross-sectional retrospective study at TEDA International Cardiovascular Hospital from September 2021 to June 2022. A total of 83 patients received primary PCI for AMI. Subsequently, a rest/stress dynamic and routine gated myocardial perfusion imaging (MPI) were performed 1 week after PCI. The CMD group was defined as having a residual stenosis of infarct-related artery (IRA) <50% and myocardial flow reserve (MFR) <2.0 in this corresponding territory, whereas MFR ≥2.0 of IRA pertained to the normal control group. Rest-AAR of infarction (%) and stress-AAR (%) were expressed by the percentage of measured rest-defect-size and stress-defect-size in the left ventricular area, respectively. Logistic regression analyses were performed to identify significant predictors of CMD. Results: A total of 53 patients with a mean age of 57.06±11.99 years were recruited, of whom 81.1% were ST-segment elevation myocardial infarction (STEMI). The proportion of patients with CMD was 79.2% (42/53). The time of pain to SPECT imaging was 7.50±1.27 days in the CMD group and 7.45±1.86 days among controls. CMD patients had a higher body mass index (BMI) than controls (26.48±3.26 vs. 24.36±2.73 kg/m2, P=0.053), and a higher proportion of STEMI, thrombolysis in myocardial infarction (TIMI) 0 grade of IRA prior PCI than controls (88.1% vs. 54.5%, P=0.011; 61.9% vs. 18.2%, P=0.004, respectively). No significant difference was identified in the rest-myocardial blood flow (MBF) of IRA between the 2 groups, whereas the stress-MBF and MFR of IRA, rest-AAR, and stress-AAR in the CMD group were remarkably lowered. Higher BMI [odds ratio (OR): 1.332, 95% confidence interval (CI): 1.008-1.760, P=0.044] and stress-AAR (OR: 1.994, 95% CI: 1.122-3.543, P=0.019) were used as independent predictors of CMD occurrence. Conclusions: The prevalence of CMD is high in AMI patients who received primary PCI. Each 1 kg/m2 increase in BMI was associated with a 1.3-fold increase in CMD risk. A 5% increase in stress-AAR was associated with a nearly 2-fold increase in CMD risk. Increased BMI and stress-AAR predicts decreased coronary reserve function.

Prevalence, clinical characteristics, and long-term outcomes of new diabetes diagnosis in elderly patients undergoing percutaneous coronary intervention.

Previous studies have reported associations between newly diagnosed diabetes and poor outcomes after percutaneous coronary intervention (PCI), but there is limited data focusing on elderly patients (age ≥ 65). This study aimed to analyze the prevalence and clinical implications of newly diagnosed diabetes in elderly patients who underwent PCI. From 2004 to 2021, a total of 2456 elderly patients who underwent invasive PCI at Korea University Guro Hospital were prospectively enrolled and followed up for a median of five years. The primary endpoint was five-year major adverse cardiovascular events (MACE). Cox regression was used to evaluate whether newly diagnosed diabetes impacted on long-term clinical outcomes. Newly diagnosed diabetes was presented in approximately 8.1% to 10.9% of elderly patients who underwent PCI. Those who had a new diagnosis of diabetes had a higher risk of MACE than previously known diabetes (25.28% vs. 19.15%, p = 0.039). After adjusting for significant factors, newly diagnosed diabetes remained an independent predictor of MACE (HR [hazard ratio] 1.64, 95% confidence interval [CI] 1.24-2.17, p < 0.001), cardiac death (HR 2.15, 95% CI 1.29-3.59, p = 0.003) and repeat revascularization (HR 1.52, 95% CI 1.09-2.11, p = 0.013), but not for non-fatal myocardial infarction (HR 1.66, 95% CI 0.94-2.12, p = 0.081). Newly diagnosed diabetes was associated with an increased risk of 5-year MACE compared with non-diabetes and previously diagnosed diabetes in elderly patients underwent PCI. More attention should be given to those elderly newly diagnosed diabetes population.

Long-term effect of a large dose of iodinated contrast in patients with mild thyroid dysfunction: a prospective cohort study.

BACKGROUND: More than 75 million procedures with intravascular iodine-based contrast media (ICM) are performed worldwide every year, and some patients undergoing these procedures do not have normal thyroid function. The long-term effects of ICM in patients with mild thyroid dysfunction (TD) are unclear. METHODS: This prospective cohort study was conducted in China. Patients with stable angina pectoris with total triiodothyronine (TT3) reduction, normal thyroid-stimulating hormone, and reverse triiodothyronine (rT3) were enrolled and divided into high-dose (≥100 mL ICM) and low-dose groups (<100 mL ICM). We dynamically investigated the trends in thyroid function, rT3, and thyroid antibodies one year after ICM exposure. RESULTS: A total of 154 patients completed 6 months of follow-up and 149 completed 1 year of follow-up. Thyroglobulin antibody (TGAB) levels were elevated in 41 (26.6%) patients before ICM exposure, 11 (7.1%) of whom also had elevated thyroid peroxidase antibody levels. Transient subclinical TD occurred 6 months after ICM exposure; 75.5% (34/45) of post-operative TD occurred in the high-dose group. One patient developed severe hypothyroidism with myxedema, requiring drug intervention 1 year after ICM exposure. The level of rT3 showed no statistically significant changes during post-operative follow-up ( P  = 0.848). The TGAB level decreased at 6th month ( P  < 0.001), but increased at 1 year after ICM exposure ( P  = 0.002). CONCLUSIONS: Patients with T3 reduction are at a risk of transient subclinical TD and hypothyroidism after a single large dose of ICM. Follow-up of this population at 9-12 months after ICM exposure is warranted.

'Smoker's paradox' in young patients with acute myocardial infarction.

1. Of the patients suffering from acute myocardial infarction (AMI), smokers are younger than non-smokers, which may be a major confounding factor causing 'smoker's paradox'. Therefore, in the present study we evaluated the 'smoker's paradox' in young patients with AMI.2. In all, 1218 young AMI patients (≤ 45 years of age), comprising 990 smokers and 228 non-smokers, were enrolled in the present study. In-hospital and 8 months clinical outcomes were compared between the smokers and non-smokers. 3. Baseline clinical characteristics showed that smokers were more likely to be male (97.9% vs 72.4%; P < 0.001) and had a higher rate of ST-segment elevation myocardial infarction (71.3% vs 59.5%; P = 0.001) than non-smokers. Clinical outcomes showed that smokers had lower rates of in-hospital cardiac death (0.8% vs 3.5%; P = 0.004), total death (0.8% vs 3.5%; P = 0.004) and 8 months cardiac death (1.1% vs 3.9%; P = 0.006) and total death (1.3% vs 4.4%; P = 0.005) than non-smokers. Multivariable logistic analysis showed that current smoking was an independent protective predictor of 8 months cardiac death (odds ratio (OR) 0.25; 95% confidence interval (CI) 0.07-0.92; P = 0.037) and total death (OR 0.26; 95% CI 0.09-0.82; P = 0.021). Subgroup analysis in patients who underwent percutaneous coronary intervention after AMI showed that current smoking was an independent protective predictor of 8 months total major adverse cardiac events (OR 0.47; 95% CI 0.23-0.97; P = 0.041). 4. Current smoking seems to be associated with better clinical outcomes in young patients with AMI, suggesting the existence of the 'smoker's paradox' in this particular subset of patients.