Toru Watanabe

Metabolic Syndrome and Risk of Development of Atrial Fibrillation The Niigata Preventive Medicine Study

Background— The metabolic syndrome consists of a cluster of atherosclerotic risk factors, many of which also have been implicated in the genesis of atrial fibrillation (AF). However, the precise role of the metabolic syndrome in the development of AF is unknown. Methods and Results— This prospective, community-based, observational cohort study was based on an annual health check-up program in Japan. We studied 28 449 participants without baseline AF. We used 2 different criteria for the metabolic syndrome—the guidelines of the National Cholesterol Education Program Third Adult Treatment Panel (NCEP-ATP III) and those of the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI)—to study the risk of development of new-onset AF. The metabolic syndrome was present in 3716 subjects (13%) and 4544 subjects (16%) using the NCEP-ATP III and AHA/NHLBI definitions, respectively. During a mean follow-up of 4.5 years, AF developed in 265 subjects (105 women). Among the metabolic syndrome components, obesity (age- and sex-adjusted hazard ratio [HR], 1.64), elevated blood pressure (HR, 1.69), low high-density lipoprotein cholesterol (HR, 1.52), and impaired fasting glucose (HR, 1.44 [NCEP-ATP III] and 1.35 [AHA/NHLBI]) showed an increased risk for AF. The association between the metabolic syndrome and AF remained significant in subjects without treated hypertension or diabetes by the NCEP-ATP III definition (HR, 1.78) but not by the AHA/NHLBI definition (HR, 1.28). Conclusions— The metabolic syndrome was associated with increased risk of AF. The metabolic derangements of the syndrome may be important in the pathogenesis of AF.

Close bidirectional relationship between chronic kidney disease and atrial fibrillation: The Niigata preventive medicine study

BACKGROUNDnAtrial fibrillation (AF) and chronic kidney disease share risk factors and pathophysiologic mechanisms, suggesting that two conditions have close relationships.nnnMETHODSnThis is a prospective community-based observational cohort study including 235,818 subjects based upon a voluntary annual health check-up program in Japan. We studied the association of kidney dysfunction at entry with subsequent new-onset AF and the association of AF at entry with the development of kidney disease.nnnRESULTSnDuring a follow-up of 5.9 +/- 2.4 years, AF developed in 2947 subjects (1.3%). Baseline serum creatinine and estimated glomerular filtration rate (GFR) were associated with risk of subsequent AF. The HRs (95% CI) for AF were 1.32 (1.08-1.62) and 1.57 (0.89-2.77) for GFR 30 to 59 and <30 mL/min per 1.73 m(2), respectively. The effect of kidney disease on risk of new-onset AF remained significant in subjects without treated hypertension or diabetes. During the follow-up, 7791 subjects (3.3%) developed kidney dysfunction (GFR <60 mL/min per 1.73 m(2)), and 11 307 subjects (4.9%) developed proteinuria. Atrial fibrillation at entry was associated with development of kidney dysfunction (HRs [95% CI], 1.77 [1.50-2.10]) and proteinuria (HR [95% CI], 2.20 [1.92-2.52]). The association persisted in subjects without treated hypertension or diabetes.nnnCONCLUSIONSnKidney dysfunction increased the risk of new onset of AF, and AF increased the risk of development of kidney disease. This finding supports the concept that the two conditions share common abnormal molecular signaling pathways contributing to their pathogenesis.

Relationship between the severity of obstructive sleep apnea and impaired glucose metabolism in patients with obstructive sleep apnea

BACKGROUNDnThe relationship between the severity of obstructive sleep apnea (OSA) and impaired glucose metabolism (IGM) has not yet been fully elucidated in patients with OSA. Accordingly, we sought to clarify this relationship in Japanese patients with OSA.nnnMETHODSnThe study population consisted of 129 Japanese patients with OSA (apnea-hypopnea index [AHI] > or = 5). A 75-g oral glucose tolerance test was performed in all patients who had not been diagnosed as diabetes mellitus (DM). IGM was defined as either diabetes mellitus (DM) or impaired glucose tolerance (IGT).nnnRESULTSnIGM was observed in 78 (60.5%) patients: DM in 39 (30.2%) and IGT in 39 (30.2%). The frequency of IGM was significantly different among patients with AHI > or = 30, those with 15 < or = AHI < 30, and those with AHI < 15 (72.1%; 53.7%; 35.0%; respectively, p=0.001). Univariate logistic regression analyses showed male sex, the BMI, the AHI, and the lowest SpO(2) to be significantly associated with IGM. A stepwise multivariate logistic regression analysis showed a male sex and the AHI to be independently associated with IGM.nnnCONCLUSIONnIGM was observed in 60.5% of Japanese patients with OSA (AHI > or = 5), and the prevalence of IGM increased according to the severity of OSA. Furthermore, the AHI was independently associated with IGM, thus suggesting that OSA may contribute to the development of IGM.

Efficacy of Single-Bolus Administration of Sodium Bicarbonate to Prevent Contrast-Induced Nephropathy in Patients With Mild Renal Insufficiency Undergoing an Elective Coronary Procedure

We sought to clarify whether a single-bolus intravenous administration of sodium bicarbonate in addition to hydration with sodium chloride prevents contrast-induced nephropathy (CIN). One hundred forty-four patients with mild renal insufficiency (serum creatinine >1.1 to <2.0 mg/dl) undergoing an elective coronary procedure were randomly assigned to the following 2 groups: standard hydration with sodium chloride plus single-bolus intravenous administration of sodium bicarbonate (20 mEq) immediately before contrast exposure (group A, n = 72) and standard hydration alone (group B, n = 72). The primary end point was development of CIN, defined as an increase >25% or >0.5 mg/dl in serum creatinine within 3 days after the procedure. Incidence of the primary end point was lower in group A than in group B (1.4% vs 12.5%, p = 0.017). Incidence of adverse clinical events (acute pulmonary edema, acute renal failure requiring dialysis, and death within 7 days of procedure) did not differ between the 2 groups (0% vs 1.4%). In conclusion, single-bolus intravenous administration of sodium bicarbonate in addition to standard hydration can more effectively prevent CIN than standard hydration alone in patients with mild renal insufficiency undergoing an elective coronary procedure.

Association Between Neutrophil Counts on Admission and Left Ventricular Function in Patients Successfully Treated With Primary Coronary Angioplasty for First Anterior Wall Acute Myocardial Infarction

Previous studies have shown that elevated white blood cells on admission, especially neutrophil counts, are associated with a higher risk of adverse events after acute myocardial infarction (AMI). 1‐ 4 However, the association of these counts with infarct size and left ventricular (LV) function in AMI has not been clarified. In this study, we sought to clarify the association of neutrophil counts on admission with infarct size estimated by the peak creatine phosphokinase level, and with LV function in the chronic phase in anterior wall AMI. To minimize the influence of confounding factors such as time to admission, infarct location, methods of reperfusion therapy, success or failure of reperfusion therapy, and patency of the infarct-related lesion on LV function in the chronic phase, we examined only patients with first anterior wall AMI (,6 hours) who had successful primary coronary angioplasty and no reocclusion of the infarct-related lesion during hospitalization. ••• We examined 60 consecutive patients (52 men and 8 women, mean age 62 6 11 years) with anterior wall AMI who were admitted within 6 hours of the onset of symptoms and met the following criteria: (1) typical chest pain lasting 30 minutes; (2) ST-segment elevation

Significance of Negative U Waves in the Precordial Leads During Anterior Wall Acute Myocardial Infarction

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Influence of the severity of obstructive sleep apnea on heart rate

2 adjacent precordial leads on the admission electrocardiogram; (3) an increase in the serum creatine phosphokinase level to more than twice the normal value; (4) no previous myocardial infarction; (5) no other heart or lung disease; (6) successful primary coronary angioplasty; (7) no reocclusion of the infarctrelated artery during the hospitalization, and Thrombolysis In Myocardial Infarction (TIMI) trial grade 3 on chronic-phase coronary arteriography; and (8) no confounding factors such as infectious disease, collagen disease, steroid use, malignancy, or surgery within 1 month of the onset of symptoms. Informed consent for revascularization therapy and follow-up cathetherization was obtained from all patients. Emergency coronary arteriography was performed using the Judkins or Amplatz techniques. Multiple projections were recorded to ensure optimal visualization of the coronary vessels. Coronary flow in the infarct-related artery was graded according to the clas

20-Hour preprocedural hydration is not superior to 5-hour preprocedural hydration in the prevention of contrast-induced increases in serum creatinine and cystatin C.

This study was conducted to clarify the clinical significance of negative U waves in the precordial leads during anterior wall acute myocardial infarction (AMI). In all, 141 patients with first anterior wall AMI (< or = 6 hours) were classified into 2 groups according to the presence (group A, n = 31) or absence (group B, n = 110) of negative U waves in the precordial leads on the admission electrocardiogram (ECG). The number of leads showing ST elevation > or = 1 mm on the admission ECG was smaller in group A than in group B (5.2 +/- 1.3 vs 6.2 +/- 1.7, p < 0.01). Emergent coronary arteriography revealed that group A had a higher incidence of good collateral circulation than group B (39% vs 19%, p < 0.05). Peak creatine kinase activity was lower in group A than in group B (1,708 +/- 1,271 vs 2,735 +/- 1,865 IU/L, p < 0.01). The number of abnormal Q waves on the predischarge ECG was smaller in group A (2.0 +/- 1.5 vs 3.4 +/- 2.0, p < 0.01). Group A had a greater left ventricular ejection fraction and better regional wall motion in the anterobasal, anterolateral, and apical regions in the chronic phase than group B. In conclusion, patients with anterior wall AMI having negative U waves in the precordial leads on admission had a relatively smaller mass of necrotic myocardium than those without the waves. Therefore, negative U waves during anterior wall AMI may be a useful marker for identifying patients with smaller infarction partly due to better collateral circulation.

Fracture of a paclitaxol-eluting stent implanted for in-stent restenosis at the site of sirolimus-eluting stent fracture

BACKGROUNDnWe sought to clarify the influence of the severity of obstructive sleep apnea (OSA) on heart rate (HR) in patients with OSA.nnnMETHODSnWe examined 136 patients who underwent overnight polysomnography together with 24-h Holter electrocardiography and who were diagnosed as having OSA [apnea-hypopnea index (AHI) >/=5]. The patients were divided into the following 3 groups: 30 with 5</= AHI <15 (group A); 33 with 15</= AHI <30 (group B); 73 with AHI >/=30 (group C). Mean HRs during 24h, wakefulness, and sleep were calculated.nnnRESULTSnMean HRs during 24h, wakefulness, and sleep were significantly higher in group C than in groups A and B. Mean HRs during 24h, wakefulness, and sleep correlated positively with AHI (Spearmans rho=0.36, p<0.001; Spearmans rho=0.32, p<0.001; Spearmans rho=0.38, p<0.001; respectively). Multiple regression analyses revealed that lnAHI was independently associated with mean HRs during 24h, wakefulness, and sleep. In 21 OSA patients who started nasal continuous positive airway pressure (nCPAP) therapy, mean HRs during 24h, wakefulness, and sleep were significantly reduced at 6 months after the initiation of nCPAP.nnnCONCLUSIONnThe severity of OSA was independently associated with mean HRs during 24h, wakefulness, and sleep, and 6-month treatment with nCPAP reduced the values. The prognostic significance of elevated mean HRs during 24h, wakefulness, and sleep is necessary to be clarified in patients with OSA.

Severe obstructive sleep apnoea is independently associated with pulmonary artery dilatation.

BACKGROUNDnAlthough intravenous hydration with isotonic saline is the standard therapy for the prevention of contrast-induced nephropathy (CIN), there is still insufficient evidence concerning the optimal timing to initiate preprocedural intravenous hydration with isotonic saline.nnnMETHODSnThis study prospectively compared the contrast-induced increases in serum creatinine and cystatin C between 5-hour preprocedural intravenous hydration with isotonic saline (5h-HS) and 20-hour preprocedural intravenous hydration with isotonic saline (20 h-HS) in 122 patients with renal insufficiency (estimated glomerular filtration rate of 15-60 ml/min/1.73 m(2)) undergoing an elective coronary procedure. The patients were randomly assigned to receive either 5h-HS (n=60) or 20 h-HS (n=62). Serum creatinine and cystatin C were measured at baseline, immediately before contrast exposure, and 24 hours and 48 hours after contrast exposure. The primary end points were the maximal absolute and percent changes in serum creatinine and cystatin C from the baseline up to 48 hours after contrast exposure.nnnRESULTSnThe maximal absolute and percent changes in serum creatinine (0.01 ± 0.13 mg/dl vs. -0.03 ± 0.16 mg/dl, p=0.16; 0.87 ± 10.05% vs. -1.50 ± 12.92%, p=0.26; respectively) and cystatin C (-0.05 ± 0.17 mg/l vs. -0.06 ± 0.17 mg/l, p=0.59; -2.94 ± 9.29% vs. -3.46 ± 9.21%, p=0.75; respectively) did not differ between the 2 regimens.nnnCONCLUSIONSn20 h-HS is not superior to 5h-HS in the prevention of the contrast-induced increases in serum creatinine and cystatin C in patients with renal insufficiency undergoing an elective coronary procedure.