Kai-Hung Cheng

Highly electronegative LDL from patients with ST-elevation myocardial infarction triggers platelet activation and aggregation

Platelet activation and aggregation underlie acute thrombosis that leads to ST-elevation myocardial infarction (STEMI). L5-highly electronegative low-density lipoprotein (LDL)-is significantly elevated in patients with STEMI. Thus, we examined the role of L5 in thrombogenesis. Plasma LDL from patients with STEMI (n = 30) was chromatographically resolved into 5 subfractions (L1-L5) with increasing electronegativity. In vitro, L5 enhanced adenosine diphosphate-stimulated platelet aggregation twofold more than did L1 and induced platelet-endothelial cell (EC) adhesion. L5 also increased P-selectin expression and glycoprotein (GP)IIb/IIIa activation and decreased cyclic adenosine monophosphate levels (n = 6, P < .01) in platelets. In vivo, injection of L5 (5 mg/kg) into C57BL/6 mice twice weekly for 6 weeks shortened tail bleeding time by 43% (n = 3; P < .01 vs L1-injected mice) and increased P-selectin expression and GPIIb/IIIa activation in platelets. Pharmacologic blockade experiments revealed that L5 signals through platelet-activating factor receptor and lectin-like oxidized LDL receptor-1 to attenuate Akt activation and trigger granule release and GPIIb/IIIa activation via protein kinase C-α. L5 but not L1 induced tissue factor and P-selectin expression in human aortic ECs (P < .01), thereby triggering platelet activation and aggregation with activated ECs. These findings indicate that elevated plasma levels of L5 may promote thrombosis that leads to STEMI.

Association of RS2200733 but Not RS10033464 on 4q25 with Atrial Fibrillation Based on the Recessive Model in a Taiwanese Population

Objectives: To determine the association between genetic variants on chromosome 4q25 and atrial fibrillation (AF) in a Taiwanese population. Methods: We enrolled 200 patients with AF (mean age: 67 ± 13 years) and 158 controls (mean age: 63 ± 10 years). The genotypes of five SNPs, RS2634073, RS2200733, RS13143308, RS2220427 and RS10033464, were determined using multiplex single base extension methods. Results: The distribution of the RS2200733 and RS10033464 genotypes did not significantly deviate from the Hardy-Weinberg equilibrium in the control group. The distribution of the RS2200733 genotypes differed significantly between the AF group and the controls (p = 0.03), whereas the distribution of the RS10033464 genotypes did not (p = 0.49). At RS2200733, patients with the CC genotype exhibited a 0.45 times higher risk of developing AF than those with the TT genotype (p = 0.02) and a recessive model was suggested (p = 0.01). After adjusting for various covariates, patients with the CC genotype remained recessively associated with a lower risk of developing AF than those with the TT genotype (odds ratio: 0.27, 95% confidence interval: 0.11–0.65; p < 0.01). Conclusions: In the Taiwanese, there is an association between SNP RS2200733 – but not RS10033464 – and the development of AF. Based on a recessive model of inheritance, individuals with SNP RS2200733 genotype CC are at a lesser risk of developing AF.

Influence of different measurement time points on brachial-ankle pulse wave velocity and ankle-brachial index in hemodialysis patients.

In order to ensure that they are reliable markers of atherosclerosis and suitable for repetitive follow-up of disease progression and management responses in hemodialysis (HD) patients, brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index (ABI) should be tested to see whether they change with different measurement time points. The aim of this study was to assess whether baPWV and ABI vary according to whether they are measured before HD, after HD, or on the next dialysis-free day. Eighty-nine patients undergoing regular HD were enrolled. The baPWV and ABI were measured 10–30 min before and after HD, and if patients agreed, on the next dialysis-free day. The third measurement of baPWV and ABI, performed 22±2 h after HD, was taken in 72 patients (81%). The body weight reduction after HD was 2.5±0.9 kg (p<0.001). The brachial and ankle systolic and diastolic blood pressures before HD were significantly higher than those after HD and on the next dialysis-free day (p≤0.038). Right and left baPWV increased significantly after HD (p≤0.006), but returned to the pre-dialysis level on the next dialysis-free day. However, the right and left ABI remained constant before and after HD, or on the next dialysis-free day (p≥0.498). In conclusion, despite the significant decrease in body weight and blood pressures, baPWV increased significantly after HD. In addition, baPWV, but not ABI, may vary at different measurement time points. Therefore, baPWV, but not ABI, should be assessed in a timely manner in HD patients.

Chewing areca nut increases the risk of coronary artery disease in taiwanese men: a case-control study

BackgroundAreca nut chewing has been reported to be associated with obesity, metabolic syndrome, hypertension, and cardiovascular mortality in previous studies. The aim of this study was to examine whether chewing areca nut increases the risk of coronary artery disease (CAD) in Taiwanese men.MethodsThis study is a hospital-based case-control study. The case patients were male patients diagnosed in Taiwan between 1996 and 2009 as having a positive Treadmill exercise test or a positive finding on the Thallium-201 single-photon emission computed tomography myocardial perfusion imaging. The case patients were further evaluated by coronary angiography to confirm their CAD. Obstructive CAD was defined as a ≥ 50% decrease in the luminal diameter of one major coronary artery. The patients who did not fulfill the above criteria of obstructive CAD were excluded.The potential controls were males who visited the same hospital for health check-ups and had a normal electrocardiogram but no history of ischemic heart disease or CAD during the time period that the case patients were diagnosed. The eligible controls were randomly selected and frequency-matched with the case patients based on age. Multiple logistic regression analyses were used to estimate the odds ratio of areca nut chewing and the risk of obstructive CAD.ResultsA total of 293 obstructive CAD patients and 720 healthy controls, all men, were analyzed. Subjects who chewed areca nut had a 3.5-fold increased risk (95% CI = 2.0-6.2) of having obstructive CAD than those without, after adjusting for other significant covariates. The dose-response relationship of chewing areca nut and the risk of obstructive CAD was also noted. After adjusting for other covariates, the 2-way additive interactions for obstructive CAD risk were also significant between areca nut use and cigarette smoking, hypertension and dyslipidemia.ConclusionsLong-term areca nut chewing was an independent risk factor of obstructive CAD in Taiwanese men. Interactive effects between chewing areca nut and cigarette smoking, hypertension, and dyslipidemia were also observed for CAD risk. Further exploration of their underlying mechanisms is necessary.

Terlipressin-related Acute Myocardial Infarction: A Case Report and Literature Review

Acute ST‐segment elevation myocardial infarction after the administration of terlipressin in patients with hemorrhagic esophageal varices is a rare but life‐threatening complication. We report the case of a 73‐year‐old female patient with esophageal variceal bleeding complicated with acute ST‐segment elevation myocardial infarction after intravenous injection of terlipressin. We discuss the underlying mechanisms of terlipressin‐related acute myocardial infarction and review the literature.

The Impact of Estradiol and 1,25(OH)2D3 on Metabolic Syndrome in Middle-Aged Taiwanese Males

In addition to adipocytokines, estradiol (E2) and vitamin D have been reported to affect insulin sensitivity, glucose homeostasis and body weight. However, studies about the impact of E2 and vitamin D on metabolic syndrome (MetS) are still limited. The aim of this study is to clarify the roles of circulating E2 and vitamin D on the risk of MetS in middle-aged Taiwanese males. A total of 655 male volunteers, including 243 subjects with MetS (mean age: 56.7±5.8 years) and 412 normal controls (mean age: 55.1±3.6 years), were evaluated. Subjects with MetS had significantly lower circulating E2, 1,25(OH)2D3, and adiponectin, and higher leptin than those without MetS (P<0.001 for all comparisons). E2 and 1,25(OH)2D3 were significantly associated with 4 individual components of MetS; more than adiponectin and leptin that were only associated with 3 individual components. In multivariate regression analysis, E2 (beta = −0.216, P<0.001) and 1,25(OH)2D3 (beta = 0.067, P = 0.045) were still significant predictors of MetS independent of adiponectin and leptin. Further large studies are needed to confirm our preliminary results and elucidate the possible mechanism.

Lipid paradox in acute myocardial infarction-the association with 30-day in-hospital mortality.

Objectives:Elevated low-density lipoprotein cholesterol and triglycerides are major risk factors for coronary artery disease. However, fatty acids from triglycerides are a major energy source, low-density lipoprotein cholesterol is critical for cell membrane synthesis, and both are critical for cell survival. This study was designed to clarify the relationship between lipid profile, morbidity as assessed by Killip classification, and 30-day mortality in patients with acute myocardial infarction. Design:A noninterventional observational study. Setting:Coronary care unit in a university hospital. Patients:Seven hundred twenty-four patients with acute myocardial infarction in the coronary care program of the Bureau of Health Promotion were analyzed. Interventions:None. Measurements and Main Results:Low-density lipoprotein cholesterol and triglyceride levels were significantly lower in high-Killip (III + IV) patients compared with low-Killip (I + II) patients and in those who died compared with those who survived beyond 30 days (both p < 0.001). After adjustment for risk factors, low-density lipoprotein cholesterol less than 62.5 mg/dL and triglycerides less than 110 mg/dL were identified as optimal threshold values for predicting 30-day mortality and were associated with hazard ratios of 1.65 (95% CI, 1.18–2.30) and 5.05 (95% CI, 1.75–14.54), and the actual mortality rates were 23% in low low-density lipoprotein, 6% in high low-density lipoprotein, 14% in low triglycerides, and 3% in high triglycerides groups, respectively. To test the synergistic effect, high-Killip patients with triglycerides less than 62.5 mg/dL and low-density lipoprotein cholesterol less than 110 mg/dL had a 10.9-fold higher adjusted risk of mortality than low-Killip patients with triglycerides greater than or equal to 62.5 mg/dL and low-density lipoprotein cholesterol greater than or equal to 110 mg/dL (p < 0.001). The lipid paradox also improved acute myocardial infarction short-term outcomes prediction on original Killip and thrombolytic in myocardial infarction scores. Conclusions:Low low-density lipoprotein cholesterol, low triglycerides, and high Killip severity were associated with significantly higher 30-day in-hospital mortality in patients presenting with acute myocardial infarction. The initial lipid profile of patients with acute myocardial infarction may therefore hold prognostic value.

Ruptured Sinus of Valsalva and Complete Atrioventricular Block Complicating Fulminant Course of Infective Endocarditis: A Case Report and Literature Review

Patients with infective endocarditis usually developed persistent fever and heart failure, especially when the valve structures are invaded and destroyed. Persistent bacteremia often leads to severe sepsis or overwhelming septic shock. Septic emboli from the vegetation will possibly result in systemic thromboembolism with multiple organ infarction. Patients with infective endocarditis have been reported to present with either ruptured sinus of Valsalva or complete atrioventricular block. However, both of these serious complications occurring in a single patient is rare. In this case report, we present a 54‐year‐old man with a previous history of alcoholic cirrhosis and chronic renal failure who suffered from a fulminant course of infective endocarditis. Simultaneously, ruptured sinus of Valsalva and complete atrioventricular block further complicated the preexisting septic shock and multiple organ failure.

Using optical coherence tomography to evaluate macular changes after surgical management for rhegmatogenous retinal detachment

Incomplete visual recovery, color vision defects, or persistent metamorphopsia may persist even after successful surgery for rhegmatogenous retinal detachment (RRD), especially in cases of RD with macula off, suggesting microstructural macular damage that standard fundus biomicroscopy could not detect. We compared spectral‐domain optical coherence tomography imaging with preoperative and postoperative visual acuity to evaluate the relationship between morphological changes in the outer retina and visual outcome after successful repair of RRD with macula on or off. We enrolled 43 patients (43 eyes) with successful repair of RRD and a minimum 6‐month follow up after surgery in this retrospective research. Patients accepted spectral‐domain optical coherence tomography postoperatively and visual acuity examination preoperatively and postoperatively. The mean age of the patients was 48.74 ± 12.68 years (range: 16–77 years). The mean visual acuity (logarithm of minimal angle of resolution) before surgery was 0.87 ± 0.70. Disrupted ellipsoid zone was noted in one of 11 eyes in the macula‐on group (9.1%) and 19 of 32 eyes in the macula‐off group (59.4%). Disrupted external limiting membrane (ELM) was noted in no eye in the macula‐on group (0%) and 11 of 32 eyes in the macula‐off group (34.4%). The macula‐off group was associated with better postoperative visual gains than the macula‐on group (p = 0.013). Patients with integrity of the ellipsoid zone and ELM were associated with significant visual improvement than patients with disruption of the ellipsoid zone or ELM.

Effect of Short-term Cardiac Memory on Ventricular Electrical Restitution and QT Intervals in Humans

Cardiac memory (CM) can alter the configuration of action potentials and the transmural repolarization gradient in ventricular tissue. This study evaluated the effects of CM on ventricular arrhythmogenicity. A total of 20 patients (12 females, 8 males; mean age, 46 ± 13 years) were enrolled. The following indicators were measured to evaluate ventricular arrhythmogenicity: (1) the action potential duration at 90% repolarization (APD 90) recorded from the right ventricular apex (RVA); (2) the maximal slope of the action potential duration restitution curve (APDR) constructed by programmed extra stimuli from RVA; and (3) the maximal corrected QT interval (QTc) and QT interval dispersion (QTd). The short‐term CM was induced by constant pacing from the RVA at a pacing cycle length (PCL) of 400 ms for 20 minutes. After induction of CM, the mean APD 90 were significantly shortened at both PCLs of 600 ms and 400 ms (252.9 ± 6.4 ms vs. 235.6 ± 6.4 ms and 231.2 ± 6.4 ms vs. 214.4 ± 7.3 ms, respectively; p = 0.001). No significant change regarding the maximal slopes of APDR were found at both PCLs of 600 ms and 400 ms (1.05 ± 0.09 vs. 0.96 ± 0.11 and 0.85 ± 0.08 vs. 0.84 ± 0.09, respectively). QTc (417.3 ± 9.1 ms vs. 454.7 ± 8.3 ms; p = 0.001), but not QTd (63.4 ± 5.4 ms vs. 65.7 ± 6.1 ms), was significantly shortened. Short‐term CM significantly decreased ventricular APD 90 and QTc, but did not significantly change the maximal slope of APDR or QTd. These results suggest that CM might not have a significant effect on ventricular arrhythmogenicity.