Effect of Intracoronary Plus Low-Dose Intravenous Tirofiban in Elderly Patients with Acute Myocardial Infarction.

BACKGROUND: To investigate the efficacy and safety of low-dose tirofiban in elderly patients undergoing primary percutaneous coronary intervention (PPCI) for acute myocardial infarction (AMI). METHODS: One hundred and four patients aged 70 years and above undergoing PPCI for AMI were divided into control (n=52) and study (n=52) groups. All patients received bolus intracoronary injection of tirofiban (10µg/kg), which was followed by intravenous infusion at 0.15µg/kg/min in the control group and at 0.075µg/kg/min in the study group for 24h. RESULTS: There was no statistically significant difference between the study group and the control group in patients with complete ST segment resolution (84.2% vs. 85.7%, P=0.851), peak high-sensitive cardiac troponin T level (5.1±1.9 vs. 5.8±2.6µg/L, P=0.123), scores of thrombus in the infarct-related artery (0.98±0.51 vs. 1.12±0.59, P=0.214), and patients with TIMI grade 3 flow (86.0% vs. 88.2%, P=0.737) after PPCI. There were no statistically significant differences between the two groups in left ventricular ejection fraction (57.1±6.3 vs. 57.7±6.1, P=0.611) and composite major adverse cardiovascular events rate (P =0.778) at 90 days after PCI. The total bleeding rate in the study group was lower than in the control group (P=0.048). CONCLUSION: In elderly patients with AMI undergoing primary PCI, low and standard dose of tirofiban exerts similar effects on platelet aggregation, coronary flow, infarct size, left ventricular systolic function and short-term clinical outcomes. Low dose regimen is associated with a lower bleeding rate than the standard dose.

Effect of ß3-adrenergic receptor on atrial L-type Ca(2+) current in rats with chronic heart failure.

OBJECTIVES: To investigate the effect of selective ß3-adrenoreceptor agonist BRL-37344 on L-type Ca(2+) current (Ica,L) and mRNA expression of L-type Ca(2+) channel α2δ-2 (Cacna2d2) in rats with chronic heart failure (CHF). METHODS: Twenty-four male Wistar rats were divided into normal control (n=6) and CHF group (n=18), which were further divided into CHF control and BRL group (0.4nmol/kg, IV, twice weekly for four weeks). Echocardiography was performed to assess the structure and function of the left atrium (LA). RESULTS: The LA in the BRL group (4.4 ± 0.2mm) was larger than in the normal control (3.5 ± 0.3mm, P<0.01) or CHF control (4.0 ± 0.2mm, P<0.05) group. The LA ejection fraction in the BRL group (36.2 ± 4.2%) was lower than in the normal control (58.0 ± 3.1%, P<0.01) or CHF control group (42.3 ± 4.8%, P<0.05). There was no difference in Ica,L density between the BRL group and CHF control group (8.3 ± 1.7 vs. 8.2 ± 2.6 pA/pF, P>0.05), which was higher than in the normal control group (6.0 ± 1.8 pA/pF, P<0.01). There was no difference in the mRNA expression of α2δ-2 (Cacna2d2) between the BRL group and CHF control group (0.264 ± 0.005 vs. 0.243 ± 0.017, P>0.05), which was also higher than in the normal control group (0.137 ± 0.013, P<0.01). CONCLUSION: ß3-Adrenoreceptor stimulation with BRL-37344 was associated with an increase in LA diameter and a decrease in LA function in chronic heart failure. These structural and function changes were not related to Ica,L or L-type Ca(2+) channel α2δ-2 (Cacna2d2) subunit in the LA myocytes.

Low-dose nesiritide improves renal function in heart failure patients following acute myocardial infarction.

This study was designed to investigate the effect of low-dose nesiritide on renal function and major cardiac events in patients with acute decompensated heart failure following acute myocardial infarction. Sixty patients were randomized into nesiritide (loading dose 0.5 microg/kg, maintenance dose 0.0075 microg/kg/min) and nitroprusside groups. Compared with the nitroprusside group, the nesiritide group had a greater heart rate reduction (P < 0.05), higher 24 h urine volume (P < 0.001), and more significant alleviation in dyspnea (P < 0.001). The prevalence of hypotension in the nesiritide group was lower than in the nitroprusside group (7.4% vs 28.5%, P < 0.05). The nesiritide group had a greater reduction in serum noradrenaline, angiotensin II, aldosterone, endothelin, and N-terminal prohormone brain natriuretic peptide (all P < 0.01). The mean serum creatinine in the nesiritide group was reduced (109.4 +/- 26.6 vs 102.8 +/- 21.6 micromol/l, P < 0.01), whereas it remained unchanged in the nitroprusside group (106.8 +/- 20 vs 106.0 +/- 19.2 micromol/l, P > 0.05). The rehospitalization or mortality rate was similar between the two groups 3 months after the therapy (P > 0.05). We conclude that low-dose nesiritide is more effective in suppressing the activation of the sympathetic and renin-angiotensin systems. It also improves the clinical symptoms and enhances renal function, but its effect on hospital readmission or mortality rate needs further investigation.

Value of radiographic esophageal imaging in determining an optimal atrial septal puncture site for percutaneous balloon mitral valvuloplasty.

OBJECTIVE: To investigate the value of radiographic esophageal imaging in facilitating transseptal catheterization in patients undergoing percutaneous balloon mitral valvuloplasty. SUBJECTS AND METHODS: A total of 468 patients were randomized into either the study group (n = 234), in which radiographic esophageal imaging by the oral administration of a contrast media took place, or the control group (n = 234), in which the Ross technique was used. Of the 468 patients, 203 were males and 265 were females. The average ages of the study and control groups were 53 +/- 16 and 51 +/- 17 years, respectively. The patients had severe left atrial enlargement, as measured using 2-dimensional echocardiography. RESULTS: In the study group, the left atrial impression on the esophagus was clearly seen, and was used to identify the puncture site on the right atrial side for the passage of the transseptal catheter. In the control group, the left atrial silhouette was not clearly shown by fluoroscopy in 112 patients (47.5%). The success rate of transseptal catheterization in the study group was higher than in the control group (99.6 vs. 45.7%, p = 0.0001). There were no complications in the study group, but pericardial tamponade occurred in 1 patient in the control group. CONCLUSION: Radiographic esophageal imaging facilitates the identification of an optimal atrial transseptal puncture site, and improves the success rate of transseptal catheterization in patients undergoing percutaneous balloon mitral valvuloplasty.

Angiographic characteristics of the coronary artery in patients with type 2 diabetes.

OBJECTIVES: To investigate the adverse effect of type 2 diabetes on coronary artery anatomy. PATIENTS AND METHODS: The coronary angiograms of 1564 consecutive patients were analyzed. The coronary lesions of patients with and without type 2 diabetes were compared. RESULTS: Seventy-four diabetic and 824 nondiabetic patients were found to have coronary artery disease. Diabetic patients had more multivessel (48.7% versus 34.7%, P<0.01), multilesion (64.9% versus 46.1%, P<0.05), extensive (51.4% versus 7.8%, P<0.01) and small vessel disease (95.2% versus 39.8%, P<0.01) than nondiabetic patients. CONCLUSIONS: Type 2 diabetes is a significant risk factor for coronary artery disease. These findings may provide useful information for the future development of therapeutic strategies.

Upregulation of ß3-adrenergic receptor expression in the atrium of rats with chronic heart failure.

OBJECTIVES: To investigate the expression of ß(3)-adrenergic receptor (ß(3)-AR) in the atrium of rats with chronic heart failure (CHF). METHODS: The heart failure rat model was established by aortic constriction. Thirty-six male Wistar rats were divided into Sham group (n = 10) and heart failure model group (n = 26), which were further divided into CHF control (CHF group) and BRL group. The rats in the BRL group were treated with a selective ß(3)-AR agonist, BRL-37344 (4.0 nmol/kg, twice weekly) for 4 weeks. RESULTS: In the BRL group, the left ventricular end-systolic pressure (83.21 ± 13.0 vs 101.50 ± 12.12 mm Hg) and the absolute values of the maximal rate of rise and fall of left ventricular pressure ([±dP/dtmax] 2.81 ± 0.04 vs 0.35 ± 0.04 and -2.72 ± 0.06 vs -3.33 ± 0.06) were lower than in the CHF group (P < .01). The left atrial mass index (LAMI) in the BRL group (0.4132 ± 0.0306) was higher than that in the CHF (0.3212 ± 0.0136) or Sham group (0.2683 ± 0.0145; P < .01). The levels of the left atrial ß(3)-AR messenger RNA (mRNA) expression in the BRL group (0.932 ± 0.055) was higher than that in the CHF (0.706 ± 0.043) or Sham group (0.310 ± 0.020; P < .01). In all animals, there was a positive correlation between the level of ß(3)-AR mRNA expression and the left or right atrial mass index (correlation coefficient ranged from 0.744 to 0.937). CONCLUSION: There is a significant increase in the ß(3)-AR mRNA expression in the atrium of rats with heart failure. The level of ß(3)-AR mRNA expression was associated with the AMI and was enhanced by a selective ß(3)-AR agonist, BRL-37344.

Effects of folic acid on cardiac myocyte apoptosis in rats with streptozotocin-induced diabetes mellitus.

BACKGROUND: The effect of folic acid on cardiac myocyte apoptosis secondary to diabetes is unknown. METHODS: Diabetic rats were divided into diabetic control (DC, n = 11), low-dose (LDF, 0.4 mg/kg/day, n = 12) and high-dose (HDF, 1.2 mg/kg/day, n = 12) folic acid groups. Non-diabetic rats (n = 11) were used as the normal control (NC). RESULTS: After 11 weeks of treatment, compared with the NC group, the DC group showed a reduced blood levels of reactive oxygen species (ROS, P < 0.01). The rate of cardiac myocyte apoptosis in the diabetic control group was also greater than in the non-diabetic control group (P < 0.01). In folic acid-treated rats, the blood levels of ROS was higher than in the diabetic control group (P < 0.05). There was a dose-dependent reduction in the rate of cardiac myocyte apoptosis in the folic acid groups (P < 0.01), and this was accompanied by an increased level of anti-apoptotic protein Bcl-2 and decreased level of pro-apoptotic protein Bax and Fas (P < 0.01). CONCLUSIONS: Dietary folic acid supplementation diminishes the cardiac myocyte apoptosis in streptozotocin-induced diabetes. The apoptosis suppression is accompanied by an increase in the expression of Bcl-2 and a decrease in Bax and Fas.

Effect of intracoronary tirofiban in patients undergoing percutaneous coronary intervention for acute coronary syndrome.

BACKGROUND: To investigate the efficacy of intracoronary tirofiban during primary percutaneous coronary intervention (PCI) for patients with acute coronary syndrome (ACS). METHODS AND RESULTS: The 118 patients aged 70 years and above (average age 75+/-2) were divided into study (n = 58, intracoronary bolus tirofiban) and control (n = 57, intravenous tirofiban) groups. The culprit vessels were targeted with primary PCI in all patients. Compared with the control group, the study group showed better Thrombolysis In Myocardial Infarction (TIMI) flow grades and TIMI myocardial perfusion grades (TMPG) immediately after PCI (p = 0.016 and 0.026, respectively). The 14-day composite major adverse cardiac events rate was lower in the study group (3.5% vs 17.5%, p = 0.030), but was similar between the 2 groups at 30 days following PCI (7.0% vs 1.7%, p = 0.350). The left ventricular ejection fraction in the study group was higher than in the control group 30 days following PCI (67.4+/-6.2% vs 60.7+/-4.6%, p = 0.033). The 14-day bleeding complication (p = 0.201) and platelet reduction rates (p = 0.984) were similar between the 2 groups. CONCLUSION: In patients with ACS undergoing primary PCI, intracoronary bolus administration of tirofiban is superior to intravenous bolus injection for improving coronary flow, myocardial perfusion and short-term clinical outcomes.

Effect of beta-blockers on beta3-adrenoceptor expression in chronic heart failure.

OBJECTIVES: To investigate the expression of beta(3)-adrenoceptors in rats with chronic heart failure, and to explore the effect of beta-blockers on beta(3)-adrenoceptor expression. MATERIALS AND METHODS: Thirty-two male Wistar rats were divided into Sham (n = 10) and heart failure (n = 22) groups. The heart failure group was treated with normal saline (Heart Failure Control, n = 6), Metoprolol (n = 8) or Carvedilol (n = 8) for 3 months. RESULTS: The left ventricular end systolic pressure (LVESP) and the absolute values of maximal rate of rise and fall of left ventricular pressure (+/-dP/dt max) in the heart failure group were lower than in the Sham group (P < 0.01), whereas the left ventricular end diastolic pressure (LVEDP) was higher (P < 0.01). The LVESP and dP/dtmax in the Carvedilol group were higher than the Metoprolol group whereas LVEDP was lower (P < 0.01). The left ventricular mass index (LVMI) in the Carvedilol group was less than the Metoprolol and Heart Failure Control groups (P < 0.01). The level of beta(3)-adrenoceptor expression in the study groups was significantly higher than the Sham group (P < 0.01). beta(3)-adrenoceptor expression in the Carvedilol group was lower than the Heart Failure Control and Metoprolol groups (P < 0.01). CONCLUSION: beta(3)-adrenoceptor expression is increased in the failing ventricles in rats. Carvedilol is more effective than Metoprolol for improving the hemodynamics and in attenuating ventricular remodeling after heart failure. Carvedilol, rather than Metoprolol, diminishes beta(3)-adrenoceptor expression in the failing ventricles.