Factors Associated with Coronary In-Stent Restenosis after Drug-Eluting Stent Implantation in Patients on Chronic Hemodialysis.

AIMS: Recently, drug-eluting stents (DESs) have been widely adopted for patients on chronic hemodialysis (HD). However, whether DES implantation is associated with a reduced rate of in-stent restenosis (ISR) is unclear. We investigated the incidence of ISR and its predictors in patients on HD after DES implantation. METHODS AND RESULTS: We analyzed 194 consecutive patients (331 lesions) on HD who underwent follow-up angiography after DES implantation. ISR was observed in 74 lesions (22.4%). Angiographically, the relative incidence of AHA/ACC type C lesion was increased (47 vs. 32%; p = 0.043), the minimal lumen diameter (MLD) before DES implantation was smaller (0.82 ± 0.49 vs. 0.97 ± 0.45 mm; p < 0.01), and the lesion length (LL) was increased (30.2 ± 16.1 vs. 24.4 ± 12.1 mm; p = 0.023) in lesions with ISR compared to those without ISR. The rate of rotational atherectomy use was also increased in lesions with ISR compared to those without ISR (50% vs. 25%; p < 0.01). In a multivariate analysis, the MLD before DES implantation (odds ratio [OR] = 0.50, 95% confidence interval [CI] 0.27-0.91, p = 0.024), LL (OR = 1.02, 95% CI 1.00-1.04, p = 0.030) and the use of rotational atherectomy (OR = 2.71, 95% CI 1.55-4.72, p < 0.01) were independent predictors of ISR. The incidence of ISR was similar between lesions treated with the first-generation (25.8%) and the second-generation DESs (20.4%). CONCLUSIONS: ISR was observed in 74 lesions (22.4%). A small MLD, long LL, and the use of rotational atherectomy were independent predictors of ISR after DES implantation in patients on HD. There was no significant difference in the ISR rate between the first- and the second-generation DESs.

Differential influence of lesion length on fractional flow reserve in intermediate coronary lesions between each coronary artery.

OBJECTIVES: This study evaluated whether the influence of lesion length on functional significance is similar between each target artery. BACKGROUND: In the presence of a similar moderate degree of stenosis, the fractional flow reserve (FFR) in the left anterior descending coronary artery (LAD) is more often <0.80 than in the other arteries. METHODS: A total of 221 lesions with intermediate stenosis on coronary angiography that underwent FFR measurement for the evaluation of myocardial ischemia were enrolled. Quantitative coronary angiographic analysis including percent diameter stenosis and lesion length was performed. The area under the receiver operating characteristics (ROC) curve was estimated for the best cutoff value as a predictor of FFR value of ≤0.80 for each coronary artery. RESULTS: Although lesion length was similar among the lesions with an FFR >0.80 at different locations, the mean lesion length was significantly longer for lesions in the right coronary artery (RCA) with an FFR ≤0.80 than for those in the LAD and left circumflex artery (13.4 ± 3.4 vs. 8.6 ± 3.1 vs. 12.0 ± 3.7 mm, p < .001). ROC analysis demonstrated that the optimal cutoff value of lesion length for predicting an FFR ≤0.80 was 10.0 mm in the LAD (0.56 area under the curve [AUC], 48% sensitivity, and 76% specificity), whereas 13.1 mm in the RCA (0.84 AUC, 67% sensitivity, and 93% specificity). CONCLUSIONS: The impact of lesion length on myocardial ischemia is different for each coronary artery. A longer lesion length is required in the RCA than in the LAD to achieve an FFR ≤0.80.

[Incidence and clinical outcome of contrast-induced nephropathy in the elderly patients].

BACKGROUND: Aging is an established risk factor for contrast-induced nephropathy (CIN). However, little information is available on the incidence and clinical outcome of CIN for the elderly patients in Japan. OBJECTIVES: We determined the incidence and clinical outcome of CIN in the Japanese elderly patient. METHODS: We studied 292 patients who had mild renal dysfunction (estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2)) at baseline and underwent coronary angiography. Patients were divided into two groups base on their age: the elderly group (age ≥ 75, n=108) and the control group (age<75, n=184). CIN was defined as a 25% increase in serum creatinine or an increase in serum creatinine by>0.5 mg/dl above the baseline value at or within 2 days post procedure. RESULTS: Patients in the elderly group had a higher incidence of CIN (14%) than those in the control group (9%). In patients who developed CIN, there was no significant difference between the two groups in baseline GFR and GFR on days 1, 2, 7 and 30 after the procedure. However, the relative increase in GFR above baseline on day 7 (-4.0 ± 6.1 vs -8.3 ± 8.0 ml/min P=0.096) and day 30 (1.5 ± 9.4 vs -10.1 ± 9.6 ml/min P=0.0017) in the elderly group was higher than that in the control group. Furthermore, death occurred in 3 patients in the elderly group (20%) whereas no patient died in the control group (P=0.092). CONCLUSION: Aging (age ≥ 75) is a risk factor for CIN in Japanese. CIN in the elderly patients may be associated with prolonged renal dysfunction and poor prognosis.

Urinary liver-type fatty acid-binding protein level as a predictive biomarker of contrast-induced acute kidney injury.

BACKGROUND: Contrast-induced acute kidney injury (CI-AKI) is a well-known complication of contrast medium exposure in patients with chronic kidney disease. However, there are no biological markers to accurately predict the onset of CI-AKI. Liver-type fatty acid-binding protein (L-FABP), an intracellular carrier protein for free fatty acids, is markedly upregulated and abundantly expressed in the proximal tubules after renal ischaemia. We prospectively investigated whether urinary L-FABP is a suitable marker for the prediction of CI-AKI. METHODS: We performed a prospective study of 220 consecutive patients with chronic kidney disease who underwent elective catheterization [serum creatinine (Cr) ≥ 1.2 mg/dL (106 M)]. Serum Cr and L-FABP levels were measured immediately before and 1 and 2 days after the procedure. CI-AKI was defined as an increase in serum Cr level of ≥ 0.3 mg/dL within 48 h after the procedure. RESULTS: We observed the development of CI-AKI in 19 patients (8.6%). Urinary L-FABP levels were significantly higher in patients with CI-AKI than those without CI-AKI before contrast medium exposure. Receiver operating characteristic analysis showed that baseline urinary L-FABP level exhibited 82% sensitivity and 69% specificity, at a cut-off value of 24.5 µg/g Cr. Using multivariate analysis, we found that independent predictors of CI-AKI development were L-FABP level of ≥ 24.5 µg/g Cr [odds ratio (OR): 9.10; 95% confidence interval (CI), 3.20-28.9], and left ventricular ejection fraction ≤ 40% (OR, 3.42; 95% CI, 1.07-10.8). CONCLUSIONS: Urinary L-FABP level is useful for predicting the onset of CI-AKI before contrast medium exposure.

Iodine 123-metaiodobenzylguanidine imaging reflect generalized sympathetic activation in patients with left ventricular dysfunction.

BACKGROUND: Iodine 123-metaiodobenzylguanidine (MIBG) imaging has been used to assess cardiac sympathetic nerve abnormalities. To determine the role of MIBG imaging as a measure of generalized sympathetic nerve activity, MIBG imaging was evaluated with muscle sympathetic nerve activity (MSNA) and plasma norepinephrine (noradrenaline) level in patients with old myocardial infarction. METHODS: Myocardial MIBG scintigraphy, MSNA and plasma norepinephrine measurement were performed within 3 days in 35 patients with old myocardial infarction. Patients were divided into three groups according to their ejection fraction (EF); preserved (EF > or = 50%, 12 patients), intermediate (35% < EF < 50%, 13 patients), or depressed (EF < or = 35%, 10 patients). The heart to mediastinum (H/M) ratio was obtained 4 h after tracer injection from the chest anterior view image. MIBG washout rate was calculated from the early and delayed images. MSNA was recorded by microneurography. RESULTS: Plasma norepinephrine level had weak negative correlations with early H/M ratio (r = 0.37, P<0.05) and delayed H/M ratio (r = 0.33, P<0.05), and a positive correlation with MIBG washout rate (r = 0.54, P<0.01). MSNA had weak negative correlations with early H/M ratio (r = 0.51, P<0.05) and delayed H/M ratio (r = 0.52, P<0.05). However, a strong correlation was found between MSNA and MIBG washout rate (r = 0.88, P<0.001). Despite no significant differences in plasma norepinephrine level and H/M ratio, patients with intermediate and depressed EF had higher MIBG washout rate and MSNA compared with those with preserved EF. CONCLUSIONS: Increased in cardiac sympathetic nerve activity was associated with augmented sympathetic outflow of the skeletal muscle and hence, MIBG washout rate allow the assessment of general sympathetic nerve activity.

Quadricuspid aortic valve associated with idiopathic dilated cardiomyopathy: A case report.

A patient without any known congenital cardiac abnormalities who suffered from ventricular tachycardia was taken to the emergency room following successful resuscitation. Transthoracic echocardiography showed diffuse left ventricle dysfunction and mild aortic regurgitation. Coronary angiography demonstrated intact coronary and suspected morphological abnormalities of the aortic valve. In addition, transesophageal echocardiography revealed a rare quadricuspid aortic valve malformation. After controlling ventricular tachycardia and congestive heart failure with optimal medical therapy, the patient had an uneventful course and was subsequently discharged 3 weeks after admission. To our knowledge, this is the first report of quadricuspid aortic valve associated with idiopathic dilated cardiomyopathy. .

Obesity as an independent risk for left ventricular diastolic dysfunction in 692 Japanese patients.

BACKGROUND: Both obesity and left ventricular (LV) diastolic dysfunction are associated with an increased risk of cardiovascular morbidity and mortality. There is a paucity of data as to whether obesity is independently associated with LV diastolic dysfunction. METHODS: Adult patients with sinus rhythm referred for a transthoracic echocardiography between July, 2007, and December, 2007, were prospectively included. Exclusion criteria were patient who had a history of congenital or valvular heart disease, treatment with pacemaker implantation or implantable cardioverter defibrillator, myocardial infarction, or impaired LV systolic function. Diastolic function was classified by an algorithm incorporating data from mitral and pulmonary venous flow indices, and Doppler tissue imaging. Body mass index (BMI) was evaluated as a categorical variable (normal weight <25.0 kg/m(2); overweight 25.0 to <30.0 kg/m(2); and obese ≥30 kg/m(2)). Logistic models were used to assess the risk of abnormal LV diastolic function associated with BMI categories. RESULTS: Of a total number of 692 patients who met all study criteria (mean 59 ± 15 year-old; 50% women, 48% hypertension, 16% diabetes, 26% overweight, 8% obese), 538 (78%) had abnormal LV diastolic function. In multivariate analyses adjusting for age, sex, and cardiovascular risk factors, obesity was independently associated with LV diastolic dysfunction (odds ratio [OR]: 2.98, 95% confidence interval [CI]: 1.12-7.88; P = 0.03) compared to normal weight. LV mass did not weaken this association (OR: 2.88, 95% CI: 1.08-7.68; P = 0.04). Overweight was not independently associated with LV diastolic dysfunction. CONCLUSION: Obesity was associated with LV diastolic dysfunction independent of cardiovascular risk factors and LV mass.

A new protocol using sodium bicarbonate for the prevention of contrast-induced nephropathy in patients undergoing coronary angiography.

Contrast-induced nephropathy (CIN) is associated with increased morbidity and mortality rates. Although a previous study reported that pretreatment with sodium bicarbonate is more effective than sodium chloride for prophylaxis of CIN, this has not been a universal finding. We performed a prospective randomized trial to investigate whether CIN can be avoided using sodium bicarbonate. In total 155 patients with a glomerular filtration rate (GFR) <60 ml/min/1.73 m(2) who were undergoing coronary angiography were enrolled. We assigned patients to sodium chloride plus sodium bicarbonate (bicarbonate group, n = 78) or sodium chloride alone (chloride group, n = 77). Infusion of sodium bicarbonate at 1 ml/kg/hour continued from 3 hours before to 6 hours after coronary angiography. CIN was defined as a 25% increase in serum creatinine from baseline value or an absolute increase of ≥0.5 mg/dl, which appeared within 2 days of contrast. Baseline GFR was not significantly different between the 2 groups. Patients in the bicarbonate group had a higher GFR than those in the chloride group on day 2 (45.8 ± 13.4 vs 40.9 ± 14.6 ml/min/1.73 m(2), p = 0.031) and at 1 month (49.5 ± 14.7 vs 43.7 ± 15.5 ml/min/1.73 m(2), p = 0.019). CIN occurred in 10 patients (13%) in the chloride group but in only 2 patients (2.6%) in the bicarbonate group (p = 0.012). Sodium chloride plus sodium bicarbonate is more effective than sodium chloride alone for prophylaxis of CIN and can lead to retention of better long-term renal function.

Contrast-induced nephropathy in patients undergoing emergency percutaneous coronary intervention for acute coronary syndrome.

Contrast-induced nephropathy (CIN) is associated with significantly increased morbidity and mortality after coronary angiography and percutaneous coronary intervention (PCI). The aim of the present study was to assess the clinical features and in-hospital outcomes of CIN after emergency PCI. The serum creatinine (SCr) concentration was measured from days 0 to 30 in 338 consecutive patients with acute coronary syndrome undergoing emergency PCI. CIN was defined as an increase in SCr of >25% or >0.5 mg/dl within 2 days after PCI. Overall, 94 patients (28%) developed CIN. The mean SCr on admission was not significantly different between patients with CIN and those without CIN. The CIN group had significantly greater SCr at days 1, 2, and 30 than did the no CIN group. Multivariate analysis showed female gender (odds ratio [OR] 2.38, 95% confidence interval [CI] 1.12 to 5.07, p = 0.025), a culprit lesion in the left anterior descending artery (OR 2.37, 95% CI 1.31 to 4.27, p = 0.0042), contrast agent volume >200 ml (OR 3.60, 95% CI 1.96 to 6.62, p <0.001) and end-diastolic pulmonary arterial pressure >15 mm Hg (OR 2.03, 95% CI 1.02 to 4.04, p <0.01) to all correlate independently with CIN. The in-hospital mortality rate was greater in the CIN group than in the no CIN group (9.6% vs 3.3%, respectively; p = 0.025). In conclusion, CIN is a frequent complication of emergency PCI for acute coronary syndrome and is associated with a greater mortality rate and persistent renal dysfunction.

Prevention of contrast-induced nephropathy by chronic pravastatin treatment in patients with cardiovascular disease and renal insufficiency.

BACKGROUND: Contrast-induced nephropathy (CIN) is known to increase morbidity and mortality of cardiovascular disease. Recent studies have shown statins prevented CIN after contrast media exposure, but optimal statin type and dosage are still unknown. PURPOSE: The aims of the present study were to evaluate whether chronic pravastatin treatment before scheduled coronary angiography or percutaneous coronary intervention could reduce the incidence of CIN and to elucidate the factors related to CIN in patients with renal insufficiency. METHODS: We studied 431 consecutive patients with renal insufficiency. One hundred ninety-four patients were receiving pravastatin treatment as standard chronic treatment of hypercholesterolemia. Serum creatinine levels were measured at baseline (pre-procedure) and within 48 h after contrast media exposure (peak post-procedure). CIN was defined as an increase in the serum creatinine values of > or = 25% or > or = 0.5 mg/dl after contrast media exposure. Logistic regression analysis was performed to evaluate the important factors related to CIN using four variables: age, pravastatin, pre-procedure serum creatinine, and contrast volume. RESULTS: CIN was observed in 36 patients (8.4%). Patients without pravastatin (p<0.01), high level pre-procedure serum creatinine (p<0.01), and high contrast volume (p=0.034) had a significantly higher incidence of CIN. Logistic regression analysis revealed that pravastatin treatment (chi(2)=6.549, p=0.011, odds ratio=0.34), pre-procedure serum creatinine (chi(2)=6.294, p=0.009, odds ratio=2.78), and contrast volume (chi(2)=4.484, p=0.034, odds ratio=1.01) were independently related to the decreased risk of CIN. CONCLUSIONS: Chronic pravastatin treatment before contrast media exposure was important for preventing CIN in patients with renal insufficiency. Also, reducing the dose of contrast media was important for preventing CIN in patients with high-baseline serum creatinine levels.

Nicorandil suppressed myocardial injury after percutaneous coronary intervention.

BACKGROUND: Nicorandil exerts beneficial effects as an adjunctive therapy for patients with ischemic heart disease. This study was designed to assess the effects of nicorandil on the myocardial protective benefits of elective percutaneous coronary intervention (PCI). METHODS: We randomly divided 49 patients scheduled to undergo elective PCI into two groups, nicorandil and control. Before PCI, the former received an intravenous bolus injection of nicorandil (4 mg), followed by continuous infusion at 6 mg/h for 24 h after intervention. Oral administration of nicorandil was continued until follow-up coronary angiography (CAG). Serial venous blood samples, for measurement of creatine kinase (CK), creatine kinase MB isoform (CK-MB), troponin I (TnI) and myoglobin, were obtained before PCI, and at 0 h, 4 h, 24 h and 48 h after PCI. Left ventricular function and left ventricular wall motion were evaluated by means of contrast ventriculography before PCI and follow-up CAG. RESULTS: At 24 h after PCI, elevations of cardiac enzymes were significantly suppressed in the nicorandil as compared to the control group; CK (78.1+/-34.9 versus 117.4+/-137.9 U/l, P=0.0141), CK-MB (1.57+/-1.90 versus 2.67+/-4.50 U/l, P=0.0485) and TnI (0.37+/-0.55 versus 0.86+/-1.65 ng/ml, P=0.0101). Regional left ventricular wall motion was significantly improved at follow-up in the nicorandil as compared to the control group. CONCLUSIONS: Nicorandil suppressed elevations of cardiac enzymes after elective PCI and left ventricular wall motion was also significantly improved at follow-up, suggesting that nicorandil enhances the myocardial protective effect of PCI against angioplasty-related myocardial injury.

Correlation of heart rate turbulence with sympathovagal balance in patients with acute myocardial infarction.

To examine the relationship among heart rate turbulence parameters, arterial baroreflex sensitivity, and cardiac sympathetic nerve activity, 15 patients with acute myocardial infarction, presenting with sinus rhythm and > or = 3 ventricular premature beats/24 hr were studied at least 2 weeks after acute myocardial infarction. Turbulence onset (TO) and turbulence slope (TS) were averaged from 3 respective ventricular premature beats. Early heart-to-mediastinum ratio (H/M), delayed H/M, and washout rate were calculated from iodine-123-metaiodobenzylguanidine (123I MIBG) scintigraphy. Arterial baroreflex sensitivity was calculated by phenyrephrine method. Arterial baroreflex sensitivity correlated significantly with TO (r = - 0.75, p < .01) and TS (r = 0.53, p < .05). TO had no correlations with early H/M, delayed H/M, and washout rate. There were no significant correlations between TS and early H/M. However, TS had significant correlation with delayed H/M (r = 0.74, p < .01) and washout rate (r = -0.71, p < .01). Thus, heart rate turbulence of TO and TS parameters depend on sympathovagal balance.

Assessment of coronary artery disease in hemodialysis patients with delayed systolic blood pressure response after exercise testing.

BACKGROUND: We evaluated usefulness of the postexercise systolic blood pressure (SBP) response for detecting coronary artery disease (CAD) in hemodialysis patients. METHODS: A treadmill exercise testing was done, and the SBP response was measured in 44 hemodialysis patients (30 men, 14 women; age 41 to 81 years). The postexercise SBP response was defined as the ratio of SBP after 3 minutes of recovery to SBP at peak exercise. RESULTS: The SBP ratio of the 25 subjects with coronary artery stenosis (1.01+/- 0.13) was significantly greater (p<0.01) than 19 subjects without coronary artery stenosis (0.83+/- 0.10). An SBP ratio greater than 0.92 identified CAD with higher sensitivity, specificity, and accuracy than did the conventional ST-segment depression criterion (76 vs. 56%, 90 vs. 53%, and 82 vs. 55%, respectively). CONCLUSION: Determination of the SBP ratio is a clinically useful, noninvasive method for accurately detecting CAD in hemodialysis patients.

Cardiovascular adaptations to exercise training after uncomplicated acute myocardial infarction.

OBJECTIVE: This study examined the cardiovascular adaptations of an exercise training program and evaluated the role of peripheral vasodilator capacity in contributing to these adaptations after myocardial infarction. DESIGN: A total of 44 consecutive patients with uncomplicated myocardial infarction underwent 3 wks of exercise training. Controls (n = 12) with comparable myocardial infarction were selected from our database and were restricted to a program with minimal activity. All patients performed cardiopulmonary exercise testing with hemodynamic measurements. Forearm and calf reactive hyperemic flow were measured by venous occlusive plethysmography as indices of peripheral vasodilator capacity. RESULTS: Despite no change in arteriovenous oxygen difference at peak exercise after training, training resulted in significant increases in oxygen consumption, cardiac output, and stroke volume and a significant decrease in systemic vascular resistance at peak exercise (overall, P < 0.05). Calf reactive hyperemic flow increased significantly after training (P < 0.001), but forearm reactive hyperemic flow did not. Furthermore, increase in calf reactive hyperemic flow after training had a positive correlation with increases in peak cardiac output, stroke volume, and oxygen consumption after training and an inverse correlation with peak systemic vascular resistance. CONCLUSIONS: Exercise training improved exercise tolerance by improving hemodynamic responses to exercise after myocardial infarction. This improved exercise performance was linked to a training-induced increase in calf vasodilator capacity.

Candesartan and arterial baroreflex sensitivity and sympathetic nerve activity in patients with mild heart failure.

The purpose of this study was to investigate the effects of candesartan on arterial baroreflex sensitivity (BRS) and sympathetic activity in patients with mild heart failure (HF). Arterial pressure, heart rate, plasma renin activity, plasma angiotensin II and noradrenaline, and muscle sympathetic nerve activity (MSNA) were measured before therapy and after 4 weeks in 20 patients with mild HF. Patients were assigned to a candesartan group (n = 10) or a placebo group (n = 10). Baroreflex sensitivity was assessed by using phenylephrine. Candesartan induced an increase in plasma renin activity and plasma angiotensin II associated with a reduction in arterial pressure without affecting heart rate. Although plasma noradrenaline was unchanged (320 +/- 322 pg/ml to 339 +/- 104 pg/ml), MSNA decreased significantly (52 +/- 11 bursts/min to 42 +/- 9 bursts/min; p < 0.01)) and BRS increased significantly (6.9 +/- 3.6 msec/mm Hg to 10.2 +/- 3.3 msec/mm Hg; p < 0.01) after candesartan. However, there were no significant changes in the measured variables in the placebo group. These data indicate that candesartan treatment enhanced BRS and reduced sympathetic activity in patients with mild HF. Thus, the inhibitory effect of candesartan on sympathetic activity may, at least in part, contribute to the beneficial effect of angiotensin II receptor blockade in patients with mild HF.