无创中心动脉压测量法的临床应用价值及不同降压药物对中心动脉压的影响

目的 (1)评价无创中心动脉压(CAP)测量法与有创测量法的一致性,初步分析CAP与肱动脉压的关系;(2)比较苯磺酸氨氯地平片与琥珀酸美托洛尔缓释片这两种药物对CAP的影响。方法 (1)入选行冠状动脉造影患者23例(男14例,女9例),年龄(62.2±10.6)岁。分别采用有创动脉导管和无创的BProTM6 000动脉脉搏波分析仪测量CAP,同时测定肱动脉压,分析无创法与有创法测量CAP的一致性及肱动脉压与CAP的关系。(2)选取45例轻中度原发性高血压患者随机分为两组,分别给予苯磺酸氨氯地平片(23例)与琥珀酸美托洛尔缓释片(22例)两种不同的降压药物,于4周后血压达标时(共40例达标)分别测量两组患者肱动脉血压及应用BProTM6000动脉脉搏波分析仪获得中心动脉收缩压(cSBP)、增压指数(AI)、心率等指标,并对两组间这些指标进行比较。结果 (1)无创cSBP均值为(135.0±21.5)mm Hg(1 mm Hg=0.133 kPa)与有创cSBP(136.6±22.5)mm Hg比较,差异无统计学意义(P>0.05),一致性好(r=0.973,P<0.01)。肱动脉收缩压(bSBP)为(143.2±23.8)mm Hg,高于有创cSBP及无创cSBP,差异有统计学意义(P<0.01);连续三次测量的cSBP与AI一致性好(P>0.05)。(2)降压治疗后两组间bSBP及cSBP比较,差异无统计学意义(P>0.05),其中bSBP分别为氨氯地平组(128.7±9.5)mm Hg、美托洛尔组(127.7±10.6)mm Hg,而cSBP分别为氨氯地平组(118.9±8.7)mmHg与美托洛尔组(121.3±10.7)mm Hg。两组间bSBP-cSBP比较,差异有统计学意义(P<0.01),其中氨氯地平组为(9.3±2.4)mm Hg较美托洛尔组(6.4±2.6)mm Hg更大。两组AI比较,氨氯地平组82.3%±9.9%小于美托洛尔组90.4%±10.2%,P<0.05。结论 (1)无创法与有创法测量cSBP的一致性及重复性好;bSBP平均值高于cSBP平均值,提示肱动脉血压不能准确反映CAP。(2)氨氯地平和美托洛尔控制bSBP的疗效相似,但氨氯地平较美托洛尔更能有效降低cSBP及AI。     

Prospectively designed overviews of recent trials comparing antihypertensive regimens based on different drug classes

Randomized trials have provided clear evidence of the beneficial effects of many different blood pressure-lowering regimens compared with placebo. The comparative effects of antihypertensive regimens based on different drug classes are less well established. The Blood Pressure Lowering Treatment Trialists' Collaboration conducted a series of prospectively designed overviews of randomized trials that compared the effects of different drug classes on major cause-specific outcomes. These overviews found no differences between the effects of regimens based on angiotensin converting enzyme inhibitors and those based on diuretics or b-blockers. There was limited evidence of small differences between regimens based on calcium antagonists and those based on diuretics or beta-blockers. The overviews of regimens based on calcium antagonists compared with those based on angiotensin converting enzyme inhibitors recorded too few events to provide reliable findings. Over the next few years, the findings of ongoing trials and future cycles of overview analyses conducted by the Collaboration should substantially add to these data.     

远隔肢体缺血适应对人体中心动脉压的影响

目的探讨通过重复肢体缺血再灌注进行远隔缺血适应对中心动脉压的影响。方法随机选取健康自愿者,给予单侧肢体5次缺血/再灌注进行缺血适应,选取实验前、每次肢体缺血中、再灌中及操作结束后30 min共12个时间点测量中心动脉舒张压、收缩压、增强压及增压指数。结果每个时间点上,重复肢体缺血再灌注对中心动脉舒张压、收缩压有降低的趋势,对增强压及增压指数无明显影响。结论通过重复肢体缺血再灌注进行远隔肢体缺血适应对中心动脉压无不利影响,是一种安全易行的治疗措施。     

Different influences on central and peripheral pulse pressure, aortic wave reflections and pulse wave velocity of three different types of antihypertensive drugs.

OBJECTIVE: To evaluate in hypertensive patients (pts) with similar peripheral blood pressure (BP) whether different antihypertensive treatments have different influences on aortic stiffness, aortic central pressures and aortic wave reflections. METHODS: In a cross-over study 41 nondiabetic hypertensives (21 women, age 35-60 yrs) were evaluated after stabilized (> 4 months) antihypertensive treatment and with casual BP between 130/80 and 160/95 mmHg. Patients were divided into 3 groups: Group I--12 pts all medicated with beta-blockers; Group II--14 pts all medicated with calcium channel blockers; Group III--15 pts all medicated with either angiotensin-converting enzyme inhibitors (ACEIs) (n = 8) or angiotensin II receptor blockers (ARBs) (n = 7). We evaluated casual BP and carotid-femoral pulse wave velocity (PWV). Systolic blood pressure (SBP) and pulse pressure (PP), left ventricular ejection duration (LVED), augmentation pressure (delta P) and augmentation index (AI%) in the aorta (a measure of aortic wave reflection), derived using radial and carotid applantation tonometry, were measured. Data are means + SEM. RESULTS: For similar casual peripheral BP values, group III vs. group I showed lower (p < 0.05) values of: aortic stiffness--PWV (10.3 +/- 0.2 vs. 11.2 +/- 0.3 m/s), central PP (48 +/- 2 vs. 55 +/- 2 mmHg), delta TP (11 +/- 3 vs. 21 +/- 3 mmHg), LVED (297 +/- 5 vs. 319 +/- 8 ms), AI% (22 +/- 4 vs. 39 +/- 3%), suggesting reduced vascular tone in the arteries and greater brachial-aortic PP amplification. Data in group II did not differ significantly from the other two groups. CONCLUSIONS: Independently of casual BP values, the three classes of antihypertensive drugs appear to have different influences on aortic stiffness, central pressures and aortic wave reflections, ACEIs or ARBs appearing to exhibit a more favorable profile.     

Persistence of treatment and blood pressure control in elderly hypertensive patients treated with different classes of antihypertensive drugs

Unsatisfactory blood pressure (BP) control in the treated hypertensive patient is largely related to poor compliance with antihypertensive drug regimens. The aim of the present study was to prospectively evaluate the rate of persistence on treatment and the extent of BP control in 301 elderly, uncomplicated grade I or II hypertensive patients randomly allocated to monotherapy with angiotensin-converting enzyme (ACE) inhibitors, calcium channel blockers (CCBs), beta-blockers, angiotensin II receptors (ARBs), or diuretics according to an open-label single-blind study design. After 24 months, the percentage of patients continuing their initial therapy was higher in those treated with ARBs (68.5%) and ACE inhibitors (64.5%) and lower in patients taking diuretics (34.4%; P<.01). The logistic regression model using ARBs as reference term showed that patients treated with ACE inhibitors (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.79-0.99) or CCBs (OR, 0.76; 95% CI, 0.54-0.85) were more likely to continue their initial antihypertensive therapy when compared with those treated with beta-blockers (OR, 0.67; 95% CI, 0.57-0.79) or diuretics (OR, 0.56; 95% CI, 0.38-0.84). The average systolic and diastolic BP decrease was greater in patients treated with ARBs (-11.2+/-4/-5.8+/-2 mm Hg), ACE inhibitors (-10.5+/-4/-5.1+/-2 mm Hg), and CCBs (-8.5+/-3/-4.6+/-2 mm Hg) and lesser in those treated with diuretics (-2.3+/-4/-2.1+/-3 mm Hg, P<.05) and beta-blockers (-4.0+/-2/-2.3+/-2 mm Hg; P<.05). The study confirms the importance of persistence with treatment for the effective management of hypertension in clinical practice.     

Effect of exercise training on central aortic pressure wave reflection in coronary artery disease

BACKGROUND: Arterial stiffness is an important factor for cardiovascular performance and a predictor of cardiovascular risk. We investigated the effect of exercise training on arterial stiffness in coronary artery disease (CAD). METHODS: Arterial stiffness was assessed before and after 12 weeks of either exercise training or standard care in CAD patients. Arterial stiffness was evaluated by aortic augmentation index and time delay of the reflected wave (Deltat) using the SphygmoCor system. RESULTS: The augmentation index decreased (30% v 26%, P <.05) and Deltat increased (136 msec v 144 msec, P <.05) in patients with CAD after 12 weeks of exercise. CONCLUSION: These results suggest that endurance exercise training improves systemic arterial stiffness in individuals with CAD.     

Differential pulse pressure response to various antihypertensive drug families

Pulse pressure (PP) is emerging as a major pressure predictor of cardiac disease. The study comprised 10 185 untreated patients with essential hypertension. A total of 5395 men and 4790 women 56+/-13 years old, with uncomplicated essential hypertension, after a 15-day washout period and after 6 months of antihypertensive monotherapy were included. All patients included in the final cohort were responders and had normalized their blood pressure. PP was decreased least with diuretics (-5 mm Hg) and most with angiotensin II receptor blockers (ARBs) and calcium antagonists (-15 mm Hg), followed by angiotensin-converting enzyme inhibitors (ACEI) (-12 mm Hg) alpha- and beta-blockers (-10 and -9 mm Hg), differentiating among antihypertensive classes (P<0.001). The magnitude of PP fall was related to the degree of left ventricular (LV) mass reduction (P<0.001), seen best with ARBs (r=0.42) and least with ACEIs (r=0.18). Of the antihypertensive medications used in everyday practice, PP decrease may be achieved best with ARBs and calcium antagonists, whereas diuretics confer poor response. PP was decreased least with diuretics (-5 mm Hg) and most with ARBs and calcium channel blockers (-15 mm Hg), followed by ACEI (-12 mm Hg) alpha- and beta-blockers (-10 and -9 mm Hg), differentiating among antihypertensive classes (P<0.001). Of the antihypertensive medications used in everyday practice, PP decrease may be achieved best with ARBs and calcium antagonists.     

中心动脉压与肱动脉压关系的探讨

目的研究中心动脉压与外周动脉压之间的关系及影响因素。方法 100例进行冠状动脉造影检查的患者,术中使用动脉导管直接测压法测量中心动脉压及肱动脉压,分析二者之间关系及年龄和高血压对中心动脉压与肱动脉压问的相关性的影响。结果 100例患者肱动脉收缩压显著高于升主动脉收缩压[(132±22)mmHg比(128±21)mm Hg,P=0.0001],肱动脉舒张压与升主动脉舒张压差异无统计学意义[(66±11)mm Hg比(67±11)mm Hg,P0.05],在老年组、非老年组及各年龄组肱动脉脉压均高于升主动脉脉压(P=0.0001);老年组的升主动脉及肱动脉脉压显著高于非老年组[(72±17)mm Hg比(52±14)mm Hg,(77±18)mm Hg比(57±15)mm Hg,P=0.0001],随着年龄的增长中心动脉脉压及肱动脉脉压均有增高的趋势,但差异无统计学意义(P0.05);高血压患者中心动脉及肱动脉脉压均显著高于非高血压患者[(65±20)mm Hg比(53±14)mm Hg,P=0.004;(69±20)mm Hg比(59±13)mm Hg,P=0.013],但是中心动脉舒张压在高血压与非高血压患者间差异无统计学意义[(68±11)mm Hg比(64±11)mm Hg,P=0.132]。结论外周动脉收缩压及脉压均高于中心动脉,与年龄及是否伴高血压无关;老年组中心动脉及外周动脉脉压均显著高于非老年组;高血压患者外周动脉及中心动脉脉压高于非高血压患者,但两者中心动脉舒张压差异无统计学意义。     

Effect of lipoproteins of different classes on platelet aggregation

The influence of high-, low- and very-low-density lipoproteins on platelet aggregation was examined in coronary patients and normal subjects. Preincubation with high-density lipoproteins was shown to drastically inhibit platelet aggregation capacity both in normal subjects and coronary patients. Preincubation with a mixture of low- and very-low-density lipoproteins had no significant effect on platelet aggregation. The suppression of platelet aggregation by high-density lipoproteins was the most obvious in washed platelets.     

Pulse pressure changes with six classes of antihypertensive agents in a randomized, controlled trial

Pulse pressure has been more strongly associated with cardiovascular outcomes, especially myocardial infarction and heart failure, than has systolic, diastolic, or mean arterial pressure in a variety of populations. Little is known, however, of the comparative effects of various classes of antihypertensive agents on pulse pressure. In retrospective analyses of the Veterans Affairs Single-Drug Therapy for Hypertension Study, we compared changes in pulse pressure with 6 classes of antihypertensive agents: 1292 men with diastolic blood pressure of 95 to 109 mm Hg on placebo were randomized to receive hydrochlorothiazide, atenolol, captopril, clonidine, diltiazem, prazosin, or placebo. Drug doses were titrated to achieve a goal diastolic blood pressure of <90 mm Hg during a 4- to 8-week medication titration phase. Pulse pressure change (placebo subtracted) was assessed from baseline to the end of the 3-month titration and 1-year maintenance. Mean baseline systolic, diastolic, and pulse pressures were 152, 99, and 53 mm Hg, respectively. Reductions in pulse pressure during titration were greater (P<0.001) with clonidine (6.7 mm Hg) and hydrochlorothiazide (6.2 mm Hg) than with captopril (2.5 mm Hg), diltiazem (1.6 mm Hg), and atenolol (1.4 mm Hg); reduction with prazosin (3.9 mm Hg) was similar to all but clonidine. After 1 year, pulse pressure was reduced significantly more (P<0.001) with hydrochlorothiazide (8.6 mm Hg) than with captopril and atenolol (4.1 mm Hg with both); clonidine (6.3 mm Hg), diltiazem (5.5 mm Hg), and prazosin (5.0 mm Hg) were intermediate. These data show that classes of antihypertensive agents differ in their ability to reduce pulse pressure. Whether these differences affect rates of cardiovascular events remains to be determined.     

Augmentation of the aortic and central arterial pressure waveform

Late systolic augmentation of the ascending aortic and central arterial pressure wave is a characteristic feature of aging, and is attributable to stiffening of the aorta and major central arteries. It is caused by increased pulse wave velocity in these vessels with early return of wave reflection from peripheral sites, predominantly in the lower part of the body. Augmentation is measurable through identification of the shoulder or early systolic peak of pressure, which corresponds to peak flow in the aorta, and measurement from this point to the second peak, or shoulder of the wave in late systole. Difficulties in measurement of augmentation arise from problems in identification of the initial shoulder, especially when this is close to the foot of the reflected wave, to amplification of the pulse wave between ascending aorta and carotid artery, and to a Venturi effect in the aorta at the peak of aortic flow. Augmentation is systematically higher in the left ventricle than in the aorta, and systematically higher in the aorta than in more peripheral arteries such as the carotid or radial. Since properties of upper limb arteries are relatively constant with age, blood pressure, gender and drug therapy, a generalized transfer function can be used to synthesize the aortic from the radial pressure waveform. Comparison of measured directly and aortic pressure calculated with the SphygmoCor process under control conditions and with nitroglycerine infusion gave values of augmentation with mean difference 0.9, SD 7.7 mmHg, which lie within AAMI criteria for equivalence, as do measures of end systolic pressure (difference 3.8, SD 3.6 mmHg).     

Method for noninvasive measurement of central aortic systolic pressure

A method for noninvasive generation of central aortic systolic pressure curves is presented. The method is based on plotting the occlusive pressure values applied at the brachial artery level against the time intervals needed for the aortic pressure wave to equalize and break through the occlusive pressure at the brachial artery level. These time intervals were obtained by measuring the time from the beginning of depolarization (the QRS complex) to the detection of the pressure wave at the temporarily occluded brachial artery. The validity of the method was documented by 3 different approaches. The pressure values measured by a device developed by us were superimposed on the simultaneously measured central intra-aortic pressure waves and all values were within one standard deviation from the central aortic recordings in 8 of the 10 patients studied. At the same time, the noninvasively recorded pressure waves were completely different from the peripheral artery pressure recorded simultaneously at the femoral artery site. The DP/DT values derived from the central aortic recordings and the noninvasive device correlated (r = 0.83). These results indicate that the noninvasive device measures the central aortic pressure or a close approximation of it. By combining noninvasive pressure measurements with volume measurements obtained by radionuclide angiography, noninvasive pressure-volume curves were generated in 10 subjects. Possible clinical application of the systolic noninvasive pressure-volume curves is suggested.     

Utilizing ambulatory blood pressure recordings to evaluate antihypertensive drug therapy.

Until recently, the efficacy and pharmacodynamics of antihypertensive agents were assessed by resting blood pressure measurements in the doctor's office or a research clinic. The limitations of the office or clinic blood pressure measurement include the lack of representation (from recording only 1 point of time in the dosing schedule), the effects of the doctor's office on the patient's blood pressure, and, perhaps more relevant, observer bias. Ambulatory monitoring of the blood pressure has gained worldwide acceptance as an alternative method to assess antihypertensive drug efficacy and the time-effect relation of a drug. The ambulatory monitoring devices have been refined and are smaller, more precise, and more reliable than earlier recording models. Although there are no reference standards for analysis of ambulatory blood pressure data, international consensus groups are presently addressing this problem. Key roles for ambulatory blood pressure recordings in clinical trials of antihypertensive agents now include determination of the entry criteria for patients, improving the assessment of peak/trough pharmacodynamics in the patient's own environment (including nocturnal/sleep readings), and evaluating efficacy through calculation of the hypertensive burden, or blood pressure load.     

肱动脉袖带血压与中心动脉血压差异的分析

目的：比较肱动脉袖带血压与中心动脉血压的差异性,并探讨两者间差异的可能影响因素及机制。方法：选择住院行诊断性冠脉造影患者128例,平均（60．87±9．36）．岁。术前测量脉搏波传导速度（PWV）,容量顺应性（C1）,振荡顺应性（C2）,术中记录升主动脉压力（中心动脉血压,CAP）,并同步测量肱动脉袖带血压。结果：（1）根据中心动脉与肱动脉袖带收缩压（SBP）差异程度分为3组：相符组（两者相差≤4mmHg）21例（16．40％）,高估组（后者高于前者,差值〉4mmHg）14例（10．94％）,低估组（后者低于前者,差值〉4mmHg）93例（72．66％）;（2）低估组人群传统心血管危险因素多,多为老年,高血压、冠心病较多（P〈0．05）;（3）低估组PWV明显增快（P〈0．05）;（4）低估组C2明显降低（P〈0．05）。结论：中老年人肱动脉袖带血压大多数低于中心动脉压,中心动脉硬化可能与之有关。     

Factors related to poor control of blood pressure with antihypertensive drug therapy

OBJECTIVES: To study the associations of patient-related and perceived healthcare-related factors with the control of blood pressure. SUBJECTS: Physicians identified all of the hypertensive patients they saw during I week in 26 health centres. Out of 2,219 patients, 80% agreed to participate, 88% of which took antihypertensive medication. METHODS: In this cross-sectional questionnaire study, based on 82 opinion statements, 14 problem indices were formed using factor analysis. Logistic regression models were used to study the associations with blood pressure control. RESULTS: Eighty per cent of the men and 79% of the women had poor blood pressure control (BP > or = 140/90 mmHg). High levels of hopelessness towards hypertension (adjusted OR 2.16; 95% confidence interval (CI) 1.20-3.88) as well as medium and high levels of frustration with treatment (adjusted OR 1.50; 95% CI 1.04-2.18 and OR 1.83; 95% CI 0.98-3.44) were associated with poor control. The perceived tension with blood pressure measurement (adjusted OR 1.60; 95% CI 1.08-2.36) was similarly associated with poor control. Non-compliance in men, old age and monotherapy were also associated with poor blood pressure control. CONCLUSION: Hopelessness, frustration with treatment, and perceived tension with blood pressure measurement are associated with poor blood pressure control.     

肱动脉血压与主动脉根部血压的相关性

目的:研究肱动脉血压与主动脉根部血压的相关性及其影响因素。方法:入选临床需要行冠状动脉(冠脉)造影的患者208例,在动脉穿刺成功后冠脉造影前同步测量主动脉根部血压和肱动脉血压各3次,取平均值,造影结果由2位以上专家判断,并测量身高、体重、臂围、腰围、臀围,计算体质指数(BMI)、腰围/臀围(WHR)、腰围/身高(WHtR)、平均血压(MBP)、主动脉根部收缩压(SBP)与肱动脉SBP的差值(S-S)、主动脉根部舒张压(DBP)与肱动脉DBP的差值(D-D)。结果:肱动脉血压与主动脉根部血压明显相关,SBP、MBP、DBP相关系数分别为0.88、0.76、0.58(P<0.01)。以血压正常和冠脉正常者肱动脉血压与主动脉根部血压相关性更高,SBP、MBP、DBP相关系数分别为0.87、0.80、0.64和0.92、0.84、0.68(P<0.01)。血压异常、冠脉狭窄、女性SBP相关性好,而DBP相关性较差,分别为0.52、0.48、0.49(P<0.01)。主动脉根部血压测值总体上高于肱动脉血压测值[S-S:-39～40(6.35±12.50)mmHg;D-D:-47～55(5.63±11.17)mmHg],多元线性回归分析发现:S-S与年龄、性别、臂围、WHR、WHtR、腰围、臀围均无关,D-D与WHR、WHtR、腰围、臀围、年龄相关,回归方程式为:D-D=329.74 76.88WHR 3.62腰围-3.42臀围-0.17年龄-375.82WHtR。结论:①主动脉根部血压与肱动脉血压有明显相关性;②WHR、WHtR、腰围、臀围、年龄影响主动脉根部与肱动脉DBP测值的差值。