厄贝沙坦对老年高血压晨峰患者微量白蛋白尿的影响及降压疗效

目的 探讨厄贝沙坦对老年高血压晨峰患者尿微量白蛋白的影响及降压疗效.方法 选择经24 h动态血压监测血压未达标的老年高血压晨峰患者92例,观察睡前加用厄贝沙坦治疗后血压及血压晨峰的变化和对尿微量白蛋白的影响.结果 治疗前92例老年高血压患者24 h平均收缩压(140.1±12.7)mm Hg,晨峰收缩压(45.6±10.8)mm Hg,尿微量白蛋白[(58.6±3.7)mg/L]明显升高,与治疗前比较,睡前加服厄贝沙坦治疗后患者24 h平均收缩压[(129.5±11.8)mm Hg]下降(t=3.18,P＜0.05),晨峰收缩压[(14.2±4.1)mm Hg]下降(t=5.74,P＜0.01),尿微量白蛋白[(31.7±3.1)mg/L]显著降低(t=5.24,P＜0.01).结论 厄贝沙坦可以有效降低老年高血压患者的血压及血压晨峰,提高血压达标率,降低尿微量白蛋白.     

Ambulatory versus clinic blood pressure for the assessment of anti hypertensive efficacy in clinical trials: insights from the Val-Syst Study

BACKGROUND: Several studies have found that measurement of blood pressure (BP) in the clinical setting may lead to overestimation of hypertension and may yield inaccurate assessments of the efficacy of antihypertensive treatment. OBJECTIVE: The aim of this study was to determine whether the use of clinic BP in the Valsartan and Amlodipine for the Treatment of Isolated Systolic Hypertension in the Elderly (Val-Syst) study accurately identified those elderly outpatients with systolic hypertension who had true 24-hour elevations in BP, as well as those who required dose increases in antihypertensive therapy during follow-up. METHODS: In Val-Syst, patients aged between 60 and 80 years with a clinic sitting systolic BP (SBP) of 160 to 220 mm Hg and a diastolic BP <90 mm Hg after a 2-week placebo washout period were randomized to receive valsartan 80 mg or amlodipine 5 mg once daily (level 1). In those with a trough SBP > or =140 mm Hg after 8 weeks of double-blind treatment, doses were titrated upward to valsartan 160 mg or amlodipine 10 mg once daily (level 2). If clinic SBP was > or =140 mm Hg after a further 8 weeks, hydrochlorothiazide 12.5 mg was added for an additional 8 weeks (level 3). Clinical decisions during the active-treatment period were based on clinic BP measurements. Thirteen of the 35 participating centers assessed ambulatory BP as well as clinic BP at baseline and the end of the treatment, making it possible to compare the results of the 2 modes of measurement. The Student test was used to compare drug-induced changes in clinic and ambulatory BP in individual patients. Differences between the decreases in clinic and ambulatory BP at the 3 treatment levels were tested using repeated-measures analysis of covariance (ANCOVA), with baseline as the covariate. RESULTS: One hundred sixty-four elderly patients (age range, 60-80 years; 85 men, 79 women) were included in the study (79 valsartan, 85 amlodipine), and valsartan and amlodipine were reported to have comparable effects on the level and rhythm of 24-hour BP In the present study, 22 of 164 patients had white-coat hypertension at baseline (clinic SBP > or =160 mm Hg and mean 24-hour SBP <130 mm Hg). For both treatments combined, the mean (SD) decreases in clinic SBP were inversely proportional to the treatment level (level 1 = -33.2 (7.9) mm Hg; level 2 = -31.6 (11.8) mm Hg; level 3 = -29.3 (11.6) mm Hg; P = 0.001, overall ANCOVA). In contrast, after adjusting for baseline values, the decreases in mean 24-hour SBP did not differ between treatment levels (level 1 = -10.8 [10.4] mm Hg; level 2 = -13.0 [11.2] mm Hg; level 3 = -16.4 [13.8] mm Hg). The decrease in clinic BP during therapy was similar in patients with white-coat hypertension and sustained hypertension (clinic SBP > or 160 mm Hg and mean 24-hour SBP > or =130 mm Hg), whereas 24-hour and 8- to 9-am SBP decreased significantly only in patients with sustained hypertension (P < 0.001). At the end of the study, mean 24-hour SBP continued to be uncontrolled (> or =130 mm Hg) in 16 of 53 patients (30.2%) at treatment level 1, 27 of 62 (43.5%) at level 2, and 19 of 49 (38.8%) at level 3 (P = NS). CONCLUSION: Based on the findings in this population of elderly patients with systolic hypertension, the management of hypertension may vary depending on whether decisions concerning the selection of patients for clinical trials and treatment adjustments during follow-up are made using clinic or ambulatory BP measurement.     

Candesartan cilexetil: comparison of once-daily versus twice-daily administration for systemic hypertension. Candesartan Cilexetil Study Investigators.

This randomized, double-masked, placebo-controlled, forced-titration, parallel-arm study was designed to compare the blood pressure (BP)-lowering effect of candesartan cilexetil, a potent antagonist of the angiotensin II receptor subtype AT1, administered once daily with that of the same agent administered twice daily at the same total daily dose of 16 mg. After a 4- to 5-week placebo run-in period, 277 patients with a sitting diastolic BP of 95 to 109 mm Hg were randomly allocated to receive placebo (n = 92) or candesartan cilexetil 8 mg once daily for 4 weeks, followed by forced titration to either 16 mg once daily (n = 91) or 8 mg twice daily (n = 94) for 4 weeks. At 8 weeks, mean reductions in trough sitting diastolic BP were similar for the once- and twice-daily treatment groups (9.4 and 10.3 mm Hg, respectively). After 8 weeks of treatment, no statistically significant differences were observed in diastolic or systolic BP, peak or trough BP, or sitting or standing BP between the 2 active-treatment groups. The rates of positive responses (defined as a trough sitting diastolic BP of <90 mm Hg or a decrease in BP of > or =10 mm Hg) were also similar (approximately 60%) in the once- and twice-daily candesartan cilexetil groups. Furthermore, placebo-corrected trough-to-peak ratios for sitting diastolic BP exceeded 75% for both candesartan cilexetil regimens, indicating a persistent 24-hour duration of drug effect. Ambulatory BP monitoring performed in a subset of patients (n = 44) confirmed the consistent 24-hour BP-lowering effect and preservation of diurnal variation with once-daily dosing. No significant between-group differences were observed in the incidence or severity of clinical or laboratory adverse events. The results of this study suggest that identical daily doses of candesartan cilexetil administered once or twice daily have comparable efficacy and tolerability and that no additional clinical benefit is derived from twice-daily administration.     

Antihypertensive activity of isradipine in humans: a new dihydropyridine calcium channel antagonist

Isradipine (Sandoz PN 200-110), a new dihydropyridine calcium channel antagonist, was evaluated in a randomized, double-blind, placebo-controlled trial for antihypertensive efficacy in 24 patients with essential hypertension. Two groups were studied: one received placebo throughout the entire study (n = 12) and the other received isradipine (n = 12), 2.5 mg b.i.d., for the first week, 5 mg b.i.d. the second week, and 10 mg b.i.d. the third week after an initial 3-week baseline placebo period. Blood pressure was measured approximately 3 hours after dosing. Isradipine, at a total daily dose of 10 mg, lowered average supine diastolic blood pressure 11.8 mm Hg, with only a 3.5 mm Hg decrease in systolic blood pressure compared with baseline. At a total daily dose of 20 mg, average supine diastolic blood pressure decreased 14.8 mm Hg and supine systolic blood pressure declined 13.9 mm Hg; both were significantly decreased compared with placebo or baseline. Heart rate was increased only minimally by isradipine. Renin level activity was increased slightly by isradipine. No serious adverse clinical or laboratory experiences were noted. Isradipine appears to be effective in lowering blood pressure without reflex tachycardia.     

Effects of delapril in combination with indapamide on blood pressure and left ventricular mass in elderly hypertensive patients

We present a single-blinded, placebo-controlled trial of the effects on blood pressure and left ventricular mass and of the safety of a combined antihypertensive treatment with delapril, a new nonsulfhydryl angiotensin-converting enzyme inhibitor, and indapamide, a sulfonamide diuretic. We studied 28 elderly patients aged 65-85 years (mean age, 69 +/- 1) with sitting systolic/diastolic blood pressure of 160-200/95-115 mm Hg (at the end of the placebo period). After a 2-week placebo run-in, patients took 30 mg delapril in combination with 1.25 mg indapamide once daily for 24 weeks. Twenty-four-hour ambulatory blood pressure was monitored and M- and B-mode echocardiography were performed before and after 24 weeks of treatment. Blood pressure decreased from 156 +/- 1.5/101 +/- 1 mm Hg before treatment to 133 +/- 1/73 +/- 1 mm Hg after treatment. The total blood pressure burden also decreased; the percentage of measurements with a systolic blood pressure > or = 140 mm Hg and a diastolic blood pressure > or = 90 mm Hg decreased from 48.7% +/- 5%/31.5% +/- 4.3% to 23.5% +/- 4%/20.5% +/- 2.9% (p < 0.0005 and p < 0.05). The area under the curve of the 24-hour blood pressure decreased from 250 +/- 41/103 +/- 21 mm Hg to 97 +/- 21/37 +/- 8.5 mm Hg (p < 0.001 and p < 0.005). The left ventricular mass index (LVMI) in the 15 patients with pretreatment left ventricular hypertrophy was reduced after therapy from 167.5 +/- 8.5 g/m 2 to 152.2 +/- 7.6 g/m 2 (p < 0.05). A positive correlation was observed between percent changes of the area under the curve of the 24-hour diastolic blood pressure and percent changes of LVMI (r = 0.6; p < 0. 05) in the 15 patients with left ventricular hypertrophy. Only 2 patients reported side effects: 1 developed skin rash and 1 developed headache. The safety of the treatment was confirmed by laboratory tests. In elderly hypertensive patients, the combination of delapril and indapamide at low doses reduced blood pressure and had favorable effects on LVMI with few side effects.     

A retrospective review of the effect of COX-2 inhibitors on blood pressure change

The objective of this study was to compare the difference between celecoxib and rofecoxib on blood pressure change. A retrospective review of medical records where the mean blood pressure in a 90-day period before and after start of the cyclooxygenase (COX)-2 inhibitors, celecoxib, and rofecoxib was compared. Data were abstracted from 249 patient records, of which 109 were included. The mean systolic blood pressures at baseline were comparable at 134.14 mm Hg and 134.05 mm Hg for the celecoxib (n = 52) and rofecoxib groups (n = 57), respectively (P = NS). A nonsignificant decrease in systolic blood pressure was observed for the celecoxib group (-1.15 mm Hg), while a statistically significant increase in systolic blood pressure was seen in the rofecoxib group (4.76 mm Hg, P = 0.044). The mean diastolic blood pressures at baseline were not significantly different between the two groups, and changes in the postperiod were also not statistically different compared with baseline values. The average total daily dose of COX-2 inhibitor was 219.2 mg for celecoxib and 25.23 mg for rofecoxib. A post hoc analysis of patients aged 65 years and older showed that the mean systolic blood pressure in the rofecoxib group increased by 7.37 mm Hg (P = 0.016), while there was an insignificant decrease for the celecoxib group (-1.94 mm Hg). This study showed that there were no significant changes in blood pressure after celecoxib initiation. While in the rofecoxib group, there was a significant increase in systolic blood pressure with an even greater increase for patients aged 65 years and older.     

A multicenter, randomized, double-blind comparison of the efficacy and safety of irbesartan and enalapril in adults with mild to moderate essential hypertension, as assessed by ambulatory blood pressure monitoring: the MAPAVEL Study (Monitorización Ambulatoria Presión Arterial APROVEL)

BACKGROUND: When blood pressure (BP)-lowering efficacy is assessed by measurements taken in a clinic setting, angiotensin II-receptor antagonists show similar efficacy to angiotensin-converting enzyme inhibitors and better tolerability. A search of MEDLINE to date, however, reveals no randomized, double-blind studies using ambulatory BP monitoring (ABPM) to compare the BP-lowering efficacy of irbesartan and enalapril in a large number of patients ( > 200) with essential hypertension. OBJECTIVE: This study compared 24-hour BP reduction and BP control, as assessed by ABPM, in patients with mild to moderate essential hypertension treated with irbesartan or enalapril. The relative tolerability of the 2 treatments was also evaluated. METHODS: This was a multicenter, randomized, double-blind study in patients with mild to moderate essential hypertension (office diastolic BP [DBP] 90-109 mm Hg or systolic BP [SBP] 140-179 mm Hg). After a 3-week, single-blind placebo washout phase, patients with a mean daytime DBP > or = 85 mm Hg, as measured by ABPM between 10 AM and 8 PM, were randomized to 12 weeks of active treatment with irbesartan or enalapril. Starting doses were 150 and 10 mg/d, respectively, with titration to 300 or 20 mg/d if clinic DBP was > or = 90 mm Hg at week 4 or 8. Based on clinic measurements, BP control was defined as a BP reading < 140/90 mm Hg after 12 weeks of treatment; patients achieving a reduction in DBP of > or = 10 mm Hg at 12 weeks were considered responders. The ABPM criterion for BP control, independent of clinic values, was achievement of a daytime BP < 130/85 mm Hg after 12 weeks of treatment; patients achieving a reduction in 24-hour DBP > or = 5 mm Hg at 12 weeks were considered responders, in dependent of clinic values. RESULTS: A total of 238 patients were randomized to treatment, 115 to irbesartan and 123 to enalapril. The study population was approximately 52.0% female and 48.0% male, with a mean ( +/- SD) age of 52.7 +/- 10.6 years. The study was completed by 111 patients in the irbesartan group (dose titrated to 300 mg/d in 72.0% of patients) and 115 patients in the enalapril group (dose titrated to 20 mg/d in 76.5% of patients). BP reductions were similar in the 2 groups, both as measured in the clinic (DBP, 12.7 +/- 8.8 mm Hg irbesartan vs 12.4 +/- 7.4 mm Hg enalapril; SBP, 19.0 +/- 14.1 mm Hg vs 17.5 +/- 14.0 mm Hg) and by 24-hour ABPM (DBP, 9.4 +/- 8.5 mm Hg vs 8.8 +/- 8.5 mm Hg: SBP, 14.7 +/- 14.7 mm Hg vs 12.6 +/- 13.1 mm Hg). As assessed by ABPM, rates of BP control were 40.5% (45/111) for irbesartan and 33.9% (39/115) for enalapril, and the response rates were a respective 71.2% (79/111) and 71.3% (82/115). The overall incidence of adverse events (40.0% irbesartan, 51.2% enalapril) was not statistically different between groups, although the incidence of adverse events considered probably related to antihypertensive treatment was significantly higher with enalapril than with irbesartan (24.6% vs 9.2%, respectively; P = 0.026), essentially because of the higher incidence of cough (8.1% vs 0.9%). CONCLUSIONS: As assessed by ABPM, irbesartan 150 to 300 mg/d was as effective in lowering BP and achieving BP control as enalapril 10 to 20 mg/d. Based on the number of treatment-related adverse events, irbesartan was better tolerated than enalapril.     

Effect of losartan plus hydrochlorothiazide on nitric oxide status in 'nondipper' hypertensive patients

The objective of this study was to investigate the effects of losartan (100 mg) plus hydrochlorothiazide (HCTZ; 25 mg) on nitric oxide (NO) production and blood pressure (BP) in "nondipper" severe hypertensive patients. Twelve hypertensive "nondipper patients" (6 of each gender) with sitting systolic/diastolic BP of 188.0 +/- 5.2/116.2 +/- 1.2 mm Hg were studied by 24-hour ambulatory blood pressure monitoring (ABPM) after daily administration of 100 mg losartan plus 25 mg HCTZ for a period of 12 weeks. Office and mean 24-hour, as well as mean awake- and sleep-time systolic/diastolic BP, serum NO levels, and urinary excretion of NO were measured after the placebo period (3 weeks) and after 12 weeks of therapy. At the end of the 12-week treatment period, the mean 24-hour systolic/diastolic BP decreased significantly from 158.6 +/- 4.7/102.2 +/- 2.6 mm Hg (placebo period) to 140.3 +/- 4.8/90.9 +/- 3.3 mm Hg (P = 0.001/< or = 0.002). The mean BP (systolic/diastolic) during the waking period was reduced from 159.3 +/- 4.4/103.0 +/- 2.5 mm Hg to 135.0 +/- 4.4/88.2 +/- 3.1 (P < or = 0.007/P < or = 0.002), whereas the mean BP (systolic/diastolic) during the sleeping hours changed from 154.9 +/- 5.3/98.9 +/- 3.1 to 140.9 +/- 4.6 (P = 0.035)/91.7 +/- 3.2 mm Hg (P = 0.035/P = 0.051). Serum NO levels increased from 40.89 +/- 5.69 microM/L (placebo period) to 67.35 +/- 6.96 microM/L (posttreatment; P < or = 0.007), whereas the 24-hour urinary NO excretion did not change significantly (69.71 +/- 3.68 microM/L [placebo period] vs 79.64 +/- 4.25 microM/L [posttreatment]; P < or = 0.16). Urinary clearance of NO also did not change. Serum NO levels increased significantly without a significant change in urinary NO excretion. BP was significantly reduced but without modifying the nondipper pattern in these patients.     

Evaluation of isradipine (PN 200-110) in mild to moderate hypertension

The efficacy and safety of isradipine (PN 200-110), a new dihydropyridine calcium antagonist, was evaluated in 87 hypertensive patients in a placebo-controlled, double-blind, randomized multicenter trial. After a 3-week single-blind washout phase, isradipine (or matching placebo) was administered for 4 weeks, beginning at 2.5 mg b.i.d. with increments of 2.5 mg b.i.d. at weekly intervals if supine diastolic blood pressure remained greater than or equal to 90 mm Hg. At the end of 1 week average supine blood pressure in the isradipine group (n = 45) fell from a baseline of 156 +/- 13/104 +/- 4 mm Hg to 146 +/- 14/97 +/- 7 mm Hg. By week 4 blood pressure was reduced by 19/14 mm Hg compared with 4/5 mm Hg in the placebo group (P less than 0.001 between groups). Supine and standing pulse rates were slightly increased initially with isradipine therapy but returned to baseline with increasing isradipine doses. Blood pressure responses at week 4 were good or excellent (supine diastolic less than or equal to 90 mm Hg or greater than or equal to 10 mm Hg decrease from baseline) in 87% of isradipine-treated patients and in 26% of placebo-treated patients. Headache, edema, abdominal discomfort, and constipation occurred slightly more frequently in isradipine-treated patients than in placebo-treated control subjects. The results indicate that isradipine, administered as monotherapy in doses of 2.5 to 10 mg b.i.d., is safe and effective in patients with mild to moderate essential hypertension.     

Treatment of hypertension in the elderly

We have evaluated the effectiveness of antihypertensive therapy for predominant systolic hypertension in 55 patients, aged 61 to 76 years, with untreated systolic blood pressures of at least 160 mm Hg and diastolic blood pressures less than 100 mm Hg. In this retrospective analysis, 41 of the patients had been treated with the centrally acting agent guanabenz (average dose 24 +/- 14 [SD] mg daily) given alone, and 14 had received a combination of guanabenz (17 +/- 10 mg daily) and hydrochlorothiazide (60 +/- 30 mg daily). After six months of therapy, each regimen significantly decreased both systolic and diastolic blood pressures. Moreover, there were no differences between the two treatment regimens in their antihypertensive efficacy, and there was no evidence of orthostatic effects. In both treatment groups, approximately 50% of the patients had excellent therapeutic responses (decrease in supine systolic blood pressure of at least 20 mm Hg). The main side effects of treatment were drowsiness and dry mouth, though these tended to be mild and of short duration. Thus, in predominant systolic hypertension in elderly patients, guanabenz, either alone or in combination with a diuretic, appears to be an effective and well tolerated form of treatment.     

Experimental Weight Gain Increases Ambulatory Blood Pressure in Healthy Subjects: Implications of Visceral Fat Accumulation

Objective

To examine whether experimentally induced weight gain raises ambulatory blood pressure (BP) in healthy subjects and identify any relationship between changes in BP and changes in regional fat distribution.

Blood pressure control in patients with mild to moderate essential hypertension switched from nifedipine gastrointestinal therapeutic system (GITS) 30 mg to nifedipine GITS 20 mg

BACKGROUND: Nifedipine gastrointestinal therapeutic system (GITS) is a once-daily formulation of nifedipine that provides sustained plasma nifedipine concentrations throughout the 24-hour dosing interval. OBJECTIVE: This study was undertaken to determine if adult patients with mild to moderate essential hypertension whose blood pressure had been controlled for > or = 3 months with nifedipine GITS 30 mg could be successfully switched to a 20-mg daily dose with continued antihypertensive efficacy. METHODS: This was a randomized, double-blind, parallel-group study. Patients entered a 1-week run-in period during which they continued to receive their usual antihypertensive medication, including nifedipine GITS 30 mg. After baseline assessment, patients entered a 6-week treatment period during which they were randomly assigned to receive nifedipine GITS 30 or 20 mg. Men and women were eligible to participate if they were > or = 55 years of age, had received a diagnosis of mild to moderate essential hypertension (sitting diastolic blood pressure [DBP] 95-114 mm Hg), and had exhibited good blood pressure control (sitting DBP < or = 90 mm Hg) while taking nifedipine GITS 30 mg once daily for > or = 3 months. Systolic blood pressure (SBP), DBP, and heart rate were recorded at baseline and after 1, 3, and 6 weeks of treatment. Adverse events were reported by patients. The responder rate was defined as the percentage of patients whose sitting DBP was < 95 mm Hg at the final study assessment. Results were based on the intent-to-treat analyses, which included data for all patients who received > or = 1 dose and had 1 postbaseline blood pressure assessment. Statistical significance was set at P < 0.05. RESULTS: Seventy-five patients entered the 1-week run-in period; 71 patients (94.7%) were randomized to treatment. Twenty-four patients received nifedipine GITS 30 mg for 43.0 +/- 3.3 days, and 47 patients received nifedipine GITS 20 mg for 42.5 +/- 6.7 days. Both groups exhibited a sustained decrease in blood pressure throughout the study; minor variations were not statistically significant. End-point SBP and DBP for the 30- and 20-mg groups were 135.5 +/- 9.8/81.7 +/- 5.4 mm Hg and 138.6 +/- 11.8/82.9 +/- 7.6 mm Hg, respectively. Changes from baseline in end-point SBP and DBP did not differ significantly between groups. At the end of treatment, goal DBP (< 95 mm Hg) was achieved by 24 of 24 patients (100%) receiving the 30-mg dose and 45 of 47 patients (95.7%) receiving the 20-mg dose. Blood pressure control (sitting DBP < 90 mm Hg) was achieved by 21 of 24 (87.5%) patients in the 30-mg group and 35 of 47 (74.5%) patients in the 20-mg group. The most commonly reported adverse event was headache; 2 patients discontinued the study because of adverse events. Overall, 9 of 24 patients (37.5%) in the 30-mg group and 14 of 47 patients (29.8%) in the 20-mg group experienced > or = 1 treatment-related adverse event. CONCLUSIONS: Patients whose mild to moderate essential hypertension is controlled with nifedipine GITS 30 mg once daily may be able to switch to 20 mg once daily with continued antihypertensive efficacy. In addition to safety and economic advantages, such a switch may be a reasonable alternative in patients with lower body weight or as an adjunct to existing antihypertensive therapy.     

老年原发性高血压患者动态脉压与左心室质量指数关系的研究

目的探讨老年原发性高血压动态脉压与左心室质量指数（LVMI）的关系。方法收集2012年1月一12月住院的110例老年原发性高血压患者的临床资料。所有患者均已行动态血压检测,并行超声心动图检查,依据24h动态血压结果计算动态脉压,依据超声心动图结果计算LVMI,按照脉压〈60mmHg（1mmHg=0．133kPa）以及≥60mmHg将患者分为A组（n=70）和B组（n=40）,比较两组患者的LVMI等指标,并采用多重线性逐步回归分析动态脉压与LVMI的关系。结果B组患者的24h平均收缩压、动态脉压较A组明显增高（P〈0．001）;B组患者的室间隔厚度、左心室后壁厚度、左心室质量、LVMI均高于A组（P〈0．05）;Pearson相关分析显示：动态脉压与LVMI呈正相关（r=0．33,P〈0．001）;多重线性逐步回归显示：动态脉压是LVMI增加的危险因素（β=0．90,P〈0．001）。结论老年原发性高血压患者动态脉压与LVMI呈正相关,动态脉压是老年原发性高血压患者左心室结构损害的重要危险因素。     

Reducing ventilation frequency during cardiopulmonary resuscitation in a porcine model of cardiac arrest

INTRODUCTION: American Heart Association/American College of Cardiology guidelines recommend a compression-to-ventilation ratio (C/V ratio) of 15:2 during cardiopulmonary resuscitation (CPR) for out-of-the-hospital cardiac arrest. Recent data have shown that frequent ventilations are unnecessary and may be harmful during CPR, since each positive-pressure ventilation increases intrathoracic pressure and may increase intracranial pressure and decrease venous blood return to the right heart and thereby decrease both the cerebral and coronary perfusion pressures. HYPOTHESIS: We hypothesized that reducing the ventilation rate by increasing the C/V ratio from 15:2 to 15:1 will increase vital-organ perfusion pressures without compromising oxygenation and acid-base balance. METHODS: Direct-current ventricular fibrillation was induced in 8 pigs. After 4 min of untreated ventricular fibrillation without ventilation, all animals received 4 min of standard CPR with a C/V ratio of 15:2. Animals were then randomized to either (A) a C/V ratio of 15:1 and then 15:2, or (B) a C/V ratio of 15:2 and then 15:1, for 3 min each. During CPR, ventilations were delivered with an automatic transport ventilator, with 100% oxygen. Right atrial pressure, intratracheal pressure (a surrogate for intrathoracic pressure), aortic pressure, and intracranial pressure were measured. Coronary perfusion pressure was calculated as diastolic aortic pressure minus right atrial pressure. Cerebral perfusion pressure was calculated as mean aortic pressure minus mean intracranial pressure. Arterial blood gas values were obtained at the end of each intervention. A paired t test was used for statistical analysis, and a p value < 0.05 was considered significant. RESULTS: The mean +/- SEM values over 1 min with either 15:2 or 15:1 C/V ratios were as follows: intratracheal pressure 0.93 +/- 0.3 mm Hg versus 0.3 +/- 0.28 mm Hg, p = 0.006; coronary perfusion pressure 10.1 +/- 4.5 mm Hg versus 19.3 +/- 3.2 mm Hg, p = 0.007; intracranial pressure 25.4 +/- 2.7 mm Hg versus 25.7 +/- 2.7 mm Hg, p = NS; mean arterial pressure 33.1 +/- 3.7 mm Hg versus 40.2 +/- 3.6 mm Hg, p = 0.007; cerebral perfusion pressure 7.7 +/- 6.2 mm Hg versus 14.5 +/- 5.5 mm Hg, p = 0.008. Minute area intratracheal pressure was 55 +/- 17 mm Hg . s versus 22.3 +/- 10 mm Hg . s, p < 0.001. End-tidal CO(2) with 15:2 versus 15:1 was 24 +/- 3.6 mm Hg versus 29 +/- 2.5 mm Hg, respectively, p = 0.001. Arterial blood gas values were not significantly changed with 15:2 versus 15:1 C/V ratios: pH 7.28 +/- 0.03 versus 7.3 +/- 0.03; P(aCO(2)) 37.7 +/- 2.9 mm Hg versus 37.6 +/- 3.5 mm Hg; and P(aO(2)) 274 +/- 36 mm Hg versus 303 +/- 51 mm Hg. CONCLUSIONS: In a porcine model of ventricular fibrillation cardiac arrest, reducing the ventilation frequency during CPR by increasing the C/V ratio from 15:2 to 15:1 resulted in improved vital-organ perfusion pressures, higher end-tidal CO(2) levels, and no change in arterial oxygen content or acid-base balance.     

Efficacy/safety of olmesartan medoxomil versus losartan potassium in patients by stage 1 or 2 hypertension

An exploratory subgroup analysis of a prospective, randomized, double-blind, forced-titration study comparing the efficacy and safety of once-daily olmesartan medoxomil (OM) and losartan potassium (LOS) in patients with stage 1 or stage 2 hypertension is reported. After a 3- to 4-week placebo run-in period, eligible patients received once-daily OM (weeks 1-4, 20 mg; weeks 5-8, 40 mg), placebo plus OM (weeks 1-2, placebo; weeks 3-4, OM 20 mg; weeks 5-8, OM 40 mg), or LOS (weeks 1-4, 50 mg; weeks 5-8, 100 mg). A subset of patients underwent ambulatory blood pressure (BP) monitoring. Efficacy endpoints by hypertension stage were mean change from baseline in seated cuff diastolic BP (SeDBP) at week 8 (primary); seated cuff systolic BP (SeSBP) at week 4 and week 8, and SeDBP at week 4 (secondary); and the change from baseline in mean 24-hour ambulatory BP at week 8, and BP target achievement (tertiary). At week 8, patients with stage 1 and stage 2 hypertension had least-squares mean SeDBP reductions from baseline of 9.9 and 9.5 mm Hg, respectively, for OM treatment, and 6.9 and 7.3 mm Hg for LOS treatment (P = 0.0095 and P = 0.0035, respectively). Overall, 63.6% of patients with stage 1 hypertension treated with OM versus 47.3% treated with LOS (P = 0.0095) achieved an SeBP of < 140/90 mm Hg, while 36.1% of patients with stage 2 hypertension treated with OM versus 25.2% treated with LOS (P = 0.0022) achieved an SeBP of < 140/90 mm Hg. At week 8, OM-treated patients with stage 2 hypertension had a significantly greater reduction in least-squares mean 24-hour ambulatory BP versus LOS-treated patients. Olmesartan and LOS were well tolerated, and the most common treatment-emergent adverse event was headache. Once-daily, maximum doses of OM in patients with stage 1 or stage 2 hypertension achieved superior BP reductions versus LOS, with similar tolerability.     

Use of peak Doppler gradient across ventricular septal defects leads to underestimation of right-sided pressures in patients with "sloped" Doppler signals.

In patients with "sloped" appearance of the Doppler signal across a ventricular septal defect (VSD), the peak Doppler velocity seems to overestimate the catheterization-derived peak-to-peak gradient, resulting in underestimation of right-sided heart pressures. In 11 patients with sloped Doppler signals across the VSD, ventricular pressure tracings were compared with simultaneous recordings of the Doppler signal. The average peak Doppler gradient (40.2 +/- 19.2 mm Hg) overestimated the catheterization-derived peak-to-peak gradient (20.2 +/- 13.6 mm Hg) significantly (P < or =.001). Doppler mean gradient (20.2 +/- 11.3 mm Hg; P = ns) and end-systolic gradient (17.0 +/- 12.5 mm Hg; P < or =.05) were closer estimates of the catheterization peak-to-peak gradient. All Doppler gradients showed good correlation to the catheterization peak-to-peak gradient with r2 values of 0.77, 0.73, and 0.91. We conclude that Doppler mean or end-systolic gradients should be used for calculation of right-sided heart pressures in this patient population.     

Effects of barnidipine on blood pressure and left ventricular diastolic function in patients with hypertension and metabolic syndrome: A 12-week, open-label noncomparison study

Background: Barnidipine is one of a new generation of dihydropyridine calcium-channel blockers. Despite evidence of favorable effects on blood pressure (BP) and insulin sensitivity, this drug has rarely been tested in hypertensive patients with metabolic syndrome (MS).Objective: The aim of this study was to evaluate the effects of barnidipine on BP and left ventricular (LV) diastolic function in patients with hypertension and MS.Methods: Consecutive subjects aged 18 to 75 years with systolic BP (SBP) of 140 to 179 mm Hg and/or diastolic BP (DBP) of 90 to 109 mm Hg and MS (based on Adult Treatment Panel III criteria) were assessed for inclusion in the study. Lifestyle changes according to current guidelines were recommended and barnidipine monotherapy 10 mg daily was initiated. All patients entered a 2-week run-in period. After a 6-week treatment period, the daily dosage was doubled for the remainder of the study in patients whose BP remained uncontrolled (≥140/≥90 mm Hg). We assessed the glycolipidic profile and LV structure and function using standard Doppler and tissue Doppler imaging (TDI) echocardiography before and after 12 weeks of treatment. Ambulatory BP records and electrocardiographic and echocardiographic tracings were coded and shipped to a central laboratory for blinded analysis. Possible adverse events (AEs) were recorded at predetermined intervals throughout the follow-up period and at unplanned intervals whenever an AE became known to the investigators.Results: Thirty-four consecutive patients were assessed for inclusion. Thirty consecutive patients (20 men, 10 women; mean {SD| age, 55.9 {10.3| years; 5 current smokers) were included in the study. At study entry, mean office SBP was 146 mm Hg, DBP was 87 mm Hg, and heart rate was 72 beats/min. At the study end, mean office SBP/DBP was <140/90 mm Hg in 20 patients (66.7%). From baseline to study end, 24-hour ambulatory BP decreased significantly by 12 and 8 mm Hg for SBP and DBP, respectively (both, P = 0.001). The smoothness index was 0.92 for SBP and 0.82 for DBP. Fasting plasma glucose concentration decreased significantly from 110 to 104 mg/dL (P = 0.001). Total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol concentrations did not change significantly. From baseline to study end, there were no significant changes in LV structure or systolic function (LV mass, 50.7 vs 50.6 g/ht^2.7; LV diastolic/systolic diameters, 47.50/29.80 vs 48.40/30.76 mm; wall motion score index, 1.0 vs 1.0; ejection fraction, 61% vs 60%), while the peak E/A velocity ratio on TDI increased from 1.078 to 1.245 (P = 0.009). No AEs (including AEs reflected by chemistry values) either unrelated or related to treatment were noted during the 12-week duration of the study.Conclusions: In these hypertensive patients with MS, a 12-week treatment period with barnidipine in addition to lifestyle modifications was associated with significant reductions in 24-hour BP and BP variability, reduction in plasma glucose concentration, and improvement in LV diastolic relaxation. No significant changes in lipid concentrations, LV structure, or systolic function were found.     

Impaired Reflex Vasoconstriction in Chronically Hypoxemic Patients

Acute hypoxia impairs vasoconstrictor responses in normal men. The present study was done to determine whether reflex vasoconstriction is impaired in chronically hypoxemic patients and whether correction of hypoxemia in these patients improves their cardiovascular reflexes. In eight chronically hypoxemic patients, arterial P(O2) was increased from an average of 45 mm Hg while breathing room air to 161 mm Hg while breathing 40-100% oxygen, with minimal changes in arterial P(CO2) or pH. Correction of hypoxemia did not cause changes in resting arterial pressure or in forearm vascular resistance, but it caused a small increase in resting heart rate. Reflex responses to lower body negative pressure, which causes pooling of blood in the lower part of the body, were observed. When the patients were hypoxemic, lower body negative pressure caused a fall in arterial pressure, slight constriction of forearm vessels, and a small increase in heart rate. When hypoxemia was corrected, the same intervention caused marked vasoconstriction and a greater increase in heart rate, and there was no decrease in arterial pressure. The results indicate that reflex vasoconstrictor responses are depressed in chronic hypoxemia, indicating that adaptive mechanisms which occur in chronic hypoxemia do not include preservation of sympathetic reflexes.     

Once-daily fixed-combination irbesartan 300 mg/ hydrochlorothiazide 25 mg and circadian blood pressure profile in patients with essential hypertension

BACKGROUND: More than 60% of patients with hypertension included in morbidity and mortality trials needed >or=2 drugs to achieve a substantial, sustained reduction in blood pressure. Tolerable combinations using higher doses of antihypertensive drugs are frequently required to control blood pressure. OBJECTIVE: The goal of this study was to assess the effect of a once-daily fixed combination of irbesartan 300 mg/hydrochlorothiazide (HCTZ) 25 mg on the circadian blood pressure profile in patients with essential hypertension that was not controlled with full-dose single therapy or low-dose combined therapy. METHODS: Study patients were recruited consecutively from the outpatient hypertension clinics of 3 university hospitals in Spain. After a 1-week washout period, patients with a mean daytime blood pressure >135/85 mm Hg were treated with irbesartan 300 mg/HCTZ 25 mg once daily for 12 weeks. Twenty-four-hour ambulatory blood pressure monitoring was performed at the end of the washout period and during the last week of treatment. RESULTS: Fifty-seven patients with essential hypertension (28 men, 29 women) were enrolled; their mean (SD) age was 60.4 (7.2) years (range, 45-78 years). After treatment, a significant reduction in both clinic and ambulatory mean (SD) blood pressure values was observed in the whole group of 57 patients (from 146.0 [11.0] mm Hg to 123.3 [13.3] mm Hg, P < 0.001 for 24-hour systolic blood pressure [SBP]; from 89.9 [8.2] mm Hg to 76.5 [9.4] mm Hg, P < 0.001 for 24-hour diastolic blood pressure [DBP]. The mean lowering of ambulatory SBP and DBP at peak was 25.2 (14.5) mm Hg and 14.7 (9.5) mm Hg, respectively, and at trough, 22.3 (18.3) mm Hg and 12.3 (10.9) mm Hg. The trough-to-peak ratio of the group was 0.92 for SBP (0.97 in responders) and 0.84 for DBP (0.89 in responders). The smoothness index, calculated as the mean of all individual values, was 1.7 (1.0) for SBP (1.8 [0.9] in responders) and 1.3 (0.8) for DBP (1.5 [0.6] in responders). Seven side effects in 6 patients were reported. No metabolic changes were observed, and no patient discontinued the study because of treatment-related adverse effects. CONCLUSIONS: The fixed combination of irbesartan 300 mg/HCTZ 25 administered once daily produced a crude meaningful effect in reducing 24-hour blood pressure and was well tolerated. The circadian profile was preserved, as shown by trough-to-peak ratios and smoothness index values for both SBP and DBP.     

Comparison of the diurnal ocular hypotensive efficacy of travoprost and latanoprost over a 44-hour period in patients with elevated intraocular pressure

BACKGROUND: Prostaglandin analogues are effective ocular hypotensive agents and are being used increasingly in the treatment of elevated intraocular pressure (IOP). These agents are typically dosed once daily. OBJECTIVES: A pilot study was conducted to evaluate the duration of travoprost's IOP-lowering efficacy up to 84 hours after the final dose in patients with open-angle glaucoma. A follow-up study was conducted to compare diurnal IOP control with travoprost and latanoprost over a 44-hour period. METHODS: In the open label pilot study, patients received 0.004% travoprost in both eyes at 8 pm daily for 2 weeks. After 2 weeks, IOP was measured before administration of the last daily dose, every 4 hours thereafter for 36 hours, and 60 and 84 hours after the last dose, with no additional ocular hypotensive medication given. In the controlled, double-masked, parallel-group, follow-up study, patients were randomized to self-administer 1 drop of the marketed doses of 0.004% travoprost or 0.005% latanoprost in both eyes at 8 pm daily for 2 weeks. At the end of this period, patients returned to the facility at approximately 8 pm for IOP measurement and administration of the final dose of study medication. IOP was then measured at 4-hour intervals for 44 hours after the last dose, with no additional ocular hypotensive medication given. RESULTS: The pilot study included 21 patients (67% female, 33% male; age range, 35-81 years) with open-angle glaucoma. IOP values were significantly below baseline at all time points up to 84 hours after the final dose of travoprost ( P<0.001). The follow-up study enrolled 35 patients, 1 of whom was excluded for missing data; thus, the intent-to-treat analysis included 34 patients (68% female, 32% male; age range, 36-72 years). At the unmedicated eligibility visit, mean IOP over 24 hours ranged from 21 to 26 mm Hg in each treatment group. After 2 weeks of treatment and 24 hours after the last dose, mean (SD) IOP was 13.1 (2.1) mm Hg (change from eligibility visit, -10.4 [2.7] mm Hg) in the travoprost group and 16.0 (3.1) mm Hg (change from eligibility visit, -7.1 [2.4] mm Hg) in the latanoprost group. The difference in change from baseline was statistically significant between treatment groups (P=0.006). Travoprost lowered IOP significantly at all time points throughout the 44-hour period after the last dose (mean IOP, 相似文献