human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background The aim of this study was to compare the antihypertensive efficacy of losartan 100 mg + hydrochlorothiazide ( HCTZ ) 25 mg versus bisoprolol 10 mg + HCTZ 25 mg and their influence on arterial stiffness and central blood pressure ( BP ) . Methods Of 60 patients with a mean BP of 173.3 ± 1.7/98.4 ± 1.2 mmHg , 59 were r and om-ized to losartan + HCTZ ( n = 32 ) or bisoprolol + HCTZ ( n = 27 ) .  Amlodipine was added if target BP was not achieved at 1 month , and doxazosin was added if target BP was not achieved after 3 months . Body mass index , office and 24-hour ambulatory BP , pulse wave velocity ( carotid-femoral [ PWVE ] and radial [ PWVM ] ) , noninvasive central systolic BP , augmentation index ( AIx ) , laboratory investigations , and electrocardiography were done at baseline and after 6 months of treatment . Results Losartan + HCTZ was as effective as bisoprolol + HCTZ , with target office BP achieved in 96.9 % and 92.6 % of patients and target 24-hour BP in 75 % and 66.7 % of patients , respectively , after 6 months . Effective treatment of BP led to significant lowering of central systolic BP , but this was decreased to a significantly ( P < 0.05 ) greater extent by losartan + HCTZ ( −23.0 ± 2.3 mmHg ) than by bisoprolol + HCTZ ( −15.4 ± 2.9 mmHg ) despite equal lowering of brachial BP . Factors correlated with central systolic BP and its lowering differed between the treatment groups . Losartan + HCTZ did not alter arterial stiffness patterns significantly , but bisoprolol + HCTZ significantly increased AIx . We noted differences in ΔPWVE , ΔPWVM , and ΔAIx between the groups in favor of losartan + HCTZ . Decreased heart rate was associated with higher central systolic BP and AIx in the bisoprolol + HCTZ group , but was not associated with increased AIx in the losartan + HCTZ group . Conclusion Although both treatments decreased both office and 24-hour BP  , losartan + HCTZ  significantly decreased central systolic BP and had a more positive influence on pulse wave velocity , with a less negative effect of decreased heart rate on AIx and central systolic BP Isolated systolic hypertension is an important risk factor for cardiovascular disease and results primarily from elastic artery stiffening . Although various drug therapies are used to lower peripheral blood pressure ( BP ) in patients with isolated systolic hypertension , the effects of the 4 major classes of antihypertensive agents on central BP , pulse pressure ( PP ) amplification , and arterial stiffness in this condition are not clear . Fifty-nine patients over the age of 60 years with untreated isolated systolic hypertension ( systolic BP ≥140 mm Hg and diastolic BP ≤90 mm Hg ) were r and omly assigned to receive 1 of the following 4 antihypertensive agents : perindopril , atenolol , lercanidipine , or bendrofluazide  . BP was measured using a mercury sphygmomanometer , and augmentation index and carotid-femoral ( aortic ) pulse wave velocity were measured at baseline , after 2 weeks of placebo therapy , and at the end of 10 weeks of active therapy . Peripheral systolic BP and peripheral PP were reduced similarly after treatment with all 4 classes of drug . However , central PP was only reduced significantly by perindopril , lercanidipine , and bendrofluazide , whereas atenolol had no effect . Lercanidipine reduced the augmentation index , whereas atenolol increased it . Aortic pulse wave velocity was not changed by any of the drugs . In summary , despite similar reductions in peripheral systolic and PPs with the 4 classes of drug , changes in central pressure and augmentation index varied . Because central PP and increased wave reflections are considered important risk factors in patients with isolated systolic hypertension , the choice of therapy may be influenced by these findings in the future Objective β-blockers ( BBs ) with different pharmacological properties may have heterogeneous effects on sympathetic nervous activity ( SNA ) and central aortic pressure ( CAP ) , which are independent cardiovascular factors for hypertension . Hence , we analyzed the effects of bisoprolol and atenolol on SNA and CAP in hypertensive patients . Methods This was a prospect i ve , r and omized , controlled study in 109 never-treated hypertensive subjects r and omized to bisoprolol ( 5 mg ) or atenolol ( 50 mg ) for 4–8 weeks .  SNA , baroreflex sensitivity ( BRS ) and heart rate ( HR ) variability ( HRV ) were measured using power spectral analysis using a Finometer . CAP and related parameters were determined using the SphygmoCor device ( pulse wave analysis ) . Results Both drugs were similarly effective in reducing brachial BP . However , central systolic BP ( −14±10 mm Hg vs −6±9 mm Hg ; P<0.001 ) and aortic pulse pressure ( −3±10 mm Hg vs + 3±8 mm Hg ; P<0.001 ) decreased more significantly with bisoprolol than with atenolol .  The augmentation index at a HR of 75 bpm ( AIxatHR75 ) was significantly decreased ( 29%±11 % to 25%±12 % ; P = 0.026 ) in the bisoprolol group only . Furthermore , the change in BRS in the bisoprolol group ( 3.99±4.19 ms/mmHg ) was higher than in the atenolol group ( 2.66±3.78 ms/mmHg ) , although not statistically significant ( P>0.05 ) . BRS was stable when RHR was controlled ( RHR≤65 bpm ) , and the two treatments had similar effects on the low frequency/high frequency ( HF ) ratio and on HF . Conclusion BBs seem to have different effects on arterial distensibility and compliance in hypertensive subjects . Compared with atenolol , bisoprolol may have a better effect on CAP . Trial Registration Clinical Trials.gov We compared dilevalol ( an isomer of labetalol ) , 200 - 400 mg daily , against atenolol , 50 - 100 mg daily , in a double-blind , crossover , placebo-controlled trial with respect to effects on arterial distensibility ( measured as pulse wave velocity [ PWV ] ) and wave reflection ( assessed from carotid pressure wave contour ) . Twelve patients of mean age 58 years ( range 44 - 73 years ) with essential hypertension ( supine diastolic blood pressure 95 - 114 mm Hg ) took active therapy for 12 weeks , separated by a 2 - 4 week placebo period .  Carotid pressure waveforms were recorded noninvasively by applanation tonometry with a Millar micromanometer-tipped probe .  PWV was measured between carotid and femoral arteries ( aortic PWV ) , carotid and radial arteries ( arm PWV ) , and femoral and pedal arteries ( leg PWV ) . Early wave reflection was calculated from the ratio of the height of the peak of the carotid wave above its shoulder to the pulse pressure and was expressed as an augmentation index . Both drugs were equally effective in reducing brachial sphygmomanometric pressure and PWV in all three regions ( active vs. placebo , p less than 0.001 ) , but there was no significant difference between the two active therapies . However , the augmentation index ( averaged during the treatment period ) was significantly lower with dilevalol ( 19 % ) than with atenolol ( 28 % , p less than 0.01 ) , corresponding to a greater decrease of 5 - 8 mm Hg in carotid systolic pressure compared with the brachial artery . Although both drugs were equally effective in reducing arterial distensibility , the vasodilating action of dilevalol gave added benefit in reducing wave reflection , presumably through its vasodilatory effect on peripheral conduit arteries BACKGROUND Different blood pressure (BP)-lowering drugs could have different effects on central aortic pressures and thus cardiovascular outcome despite similar effects on brachial BP . The Conduit Artery Function Evaluation ( CAFE ) study , a sub study of the Anglo-Sc and inavian Cardiac Outcomes Trial ( ASCOT ) , examined the impact of 2 different BP lowering-regimens ( atenolol+/-thiazide-based versus amlodipine+/-perindopril-based therapy ) on derived central aortic pressures and hemodynamics . METHODS AND RESULTS The CAFE study recruited 2199 patients in 5 ASCOT centers . Radial artery applanation tonometry and pulse wave analysis were used to derive central aortic pressures and hemodynamic indexes on repeated visits for up to 4 years . Most patients received combination therapy throughout the study . Despite similar brachial systolic BPs between treatment groups ( Delta0.7 mm Hg ; 95 % CI , -0.4 to 1.7 ; P=0.2 ) , there were substantial reductions in central aortic pressures with the amlodipine regimen ( central aortic systolic BP , Delta4.3 mm Hg ; 95 % CI , 3.3 to 5.4 ; P<0.0001 ; central aortic pulse pressure , Delta3.0 mm Hg ; 95 % CI , 2.1 to 3.9 ; P<0.0001 ) . Cox proportional-hazards modeling showed that central pulse pressure was significantly associated with a post hoc-defined composite outcome of total cardiovascular events/ procedures and development of renal impairment in the CAFE cohort ( unadjusted , P<0.0001 ; adjusted for baseline variables , P<0.05 ) . CONCLUSIONS BP-lowering drugs can have substantially different effects on central aortic pressures and hemodynamics despite a similar impact on brachial BP . Moreover , central aortic pulse pressure may be a determinant of clinical outcomes , and differences in central aortic pressures may be a potential mechanism to explain the different clinical outcomes between the 2 BP treatment arms in ASCOT Antihypertensive agents may , even within the same class , exert variable effects on arterial stiffness variables .  Nebivolol could have a better impact than atenolol on arterial stiffness , by increasing the bioavailability of endothelium-derived nitric oxide . Angiotensin-converting enzyme inhibitors ( ACEIs ) and angiotensin receptor blockers ( ARBs ) increase plasma renin activity ( enhancing the production of angiotensin II via non-ACE-related pathways ) whereas aliskiren does not , potentially affecting central hemodynamics differently . We compared the effects of two renin-angiotensin-aldosterone system ( RAAS ) inhibitors ( quinapril and aliskiren ) and 2 beta-blockers ( atenolol and nebivolol ) on arterial stiffness variables . Treatment-naïve patients ( n = 72 ; 68.1 % males ; age , 47.6 ± 10.6 years ) with uncomplicated stage I-II essential hypertension were r and omly assigned to quinapril , aliskiren , atenolol , or nebivolol for 10 weeks . Central systolic and diastolic blood pressure ( BP ) , central pulse pressure ( PP ) , augmentation index ( AIx ) , and pulse wave velocity ( PWV ) were measured at baseline , 2 , and 10 weeks . The same measurements were performed in 20 normotensive subjects ( 65.0 % males ; age , 40.0 ± 8.9 years ) . Peripheral and central systolic and diastolic BP , peripheral PP , and PWV were significantly and similarly reduced by all agents . However , PWV continued to decline between the second and last visit in patients on quinapril and aliskiren but did not change in those on nebivolol or atenolol  . Central PP and AIx decreased in patients on quinapril , aliskiren , and nebivolol but did not change in those taking atenolol . The decrease in central PP and AIx did not differ between patients on quinapril , aliskiren , and nebivolol . Despite similar reductions in peripheral BP , atenolol is less effective than nebivolol and RAAS inhibitors in improving central pulsatile hemodynamics . Aliskiren exerts similar effects on markers of arterial stiffness  as quinapril . The clinical relevance of these differences remains to be established Background . Hypertension is common after liver transplantation . There are few published data on optimum treatment . Augmentation index ( AIx ) is a measure of arterial wave reflection determined by pulse wave analysis . Methods . Amlodipine was administered to 24 hypertensive liver transplant recipients . Thirteen patients intolerant of or unresponsive to amlodipine  were r and omized to a crossover study comparing bisoprolol with lisinopril . Results . With amlodipine  , systolic blood pressure ( SBP ) fell from  
    Output:
    
agent
In conclusion , NVBBs , but not VBBs , determine a lower reduction in cSBP than in pSBP .
However , the difference in treatment-induced SBP amplification changes between NVBB and VBB is nearly abolished after accounting for differences in heart rate changes
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background The aim of this study was to compare the antihypertensive efficacy of losartan 100 mg + hydrochlorothiazide ( HCTZ ) 25 mg versus bisoprolol 10 mg + HCTZ 25 mg and their influence on arterial stiffness and central blood pressure ( BP ) . Methods Of 60 patients with a mean BP of 173.3 ± 1.7/98.4 ± 1.2 mmHg , 59 were r and om-ized to losartan + HCTZ ( n = 32 ) or bisoprolol + HCTZ ( n = 27 ) .  Amlodipine was added if target BP was not achieved at 1 month , and doxazosin was added if target BP was not achieved after 3 months . Body mass index , office and 24-hour ambulatory BP , pulse wave velocity ( carotid-femoral [ PWVE ] and radial [ PWVM ] ) , noninvasive central systolic BP , augmentation index ( AIx ) , laboratory investigations , and electrocardiography were done at baseline and after 6 months of treatment . Results Losartan + HCTZ was as effective as bisoprolol + HCTZ , with target office BP achieved in 96.9 % and 92.6 % of patients and target 24-hour BP in 75 % and 66.7 % of patients , respectively , after 6 months . Effective treatment of BP led to significant lowering of central systolic BP , but this was decreased to a significantly ( P < 0.05 ) greater extent by losartan + HCTZ ( −23.0 ± 2.3 mmHg ) than by bisoprolol + HCTZ ( −15.4 ± 2.9 mmHg ) despite equal lowering of brachial BP . Factors correlated with central systolic BP and its lowering differed between the treatment groups . Losartan + HCTZ did not alter arterial stiffness patterns significantly , but bisoprolol + HCTZ significantly increased AIx . We noted differences in ΔPWVE , ΔPWVM , and ΔAIx between the groups in favor of losartan + HCTZ . Decreased heart rate was associated with higher central systolic BP and AIx in the bisoprolol + HCTZ group , but was not associated with increased AIx in the losartan + HCTZ group . Conclusion Although both treatments decreased both office and 24-hour BP  , losartan + HCTZ  significantly decreased central systolic BP and had a more positive influence on pulse wave velocity , with a less negative effect of decreased heart rate on AIx and central systolic BP Isolated systolic hypertension is an important risk factor for cardiovascular disease and results primarily from elastic artery stiffening . Although various drug therapies are used to lower peripheral blood pressure ( BP ) in patients with isolated systolic hypertension , the effects of the 4 major classes of antihypertensive agents on central BP , pulse pressure ( PP ) amplification , and arterial stiffness in this condition are not clear . Fifty-nine patients over the age of 60 years with untreated isolated systolic hypertension ( systolic BP ≥140 mm Hg and diastolic BP ≤90 mm Hg ) were r and omly assigned to receive 1 of the following 4 antihypertensive agents : perindopril , atenolol , lercanidipine , or bendrofluazide  . BP was measured using a mercury sphygmomanometer , and augmentation index and carotid-femoral ( aortic ) pulse wave velocity were measured at baseline , after 2 weeks of placebo therapy , and at the end of 10 weeks of active therapy . Peripheral systolic BP and peripheral PP were reduced similarly after treatment with all 4 classes of drug . However , central PP was only reduced significantly by perindopril , lercanidipine , and bendrofluazide , whereas atenolol had no effect . Lercanidipine reduced the augmentation index , whereas atenolol increased it . Aortic pulse wave velocity was not changed by any of the drugs . In summary , despite similar reductions in peripheral systolic and PPs with the 4 classes of drug , changes in central pressure and augmentation index varied . Because central PP and increased wave reflections are considered important risk factors in patients with isolated systolic hypertension , the choice of therapy may be influenced by these findings in the future Objective β-blockers ( BBs ) with different pharmacological properties may have heterogeneous effects on sympathetic nervous activity ( SNA ) and central aortic pressure ( CAP ) , which are independent cardiovascular factors for hypertension . Hence , we analyzed the effects of bisoprolol and atenolol on SNA and CAP in hypertensive patients . Methods This was a prospect i ve , r and omized , controlled study in 109 never-treated hypertensive subjects r and omized to bisoprolol ( 5 mg ) or atenolol ( 50 mg ) for 4–8 weeks .  SNA , baroreflex sensitivity ( BRS ) and heart rate ( HR ) variability ( HRV ) were measured using power spectral analysis using a Finometer . CAP and related parameters were determined using the SphygmoCor device ( pulse wave analysis ) . Results Both drugs were similarly effective in reducing brachial BP . However , central systolic BP ( −14±10 mm Hg vs −6±9 mm Hg ; P<0.001 ) and aortic pulse pressure ( −3±10 mm Hg vs + 3±8 mm Hg ; P<0.001 ) decreased more significantly with bisoprolol than with atenolol .  The augmentation index at a HR of 75 bpm ( AIxatHR75 ) was significantly decreased ( 29%±11 % to 25%±12 % ; P = 0.026 ) in the bisoprolol group only . Furthermore , the change in BRS in the bisoprolol group ( 3.99±4.19 ms/mmHg ) was higher than in the atenolol group ( 2.66±3.78 ms/mmHg ) , although not statistically significant ( P>0.05 ) . BRS was stable when RHR was controlled ( RHR≤65 bpm ) , and the two treatments had similar effects on the low frequency/high frequency ( HF ) ratio and on HF . Conclusion BBs seem to have different effects on arterial distensibility and compliance in hypertensive subjects . Compared with atenolol , bisoprolol may have a better effect on CAP . Trial Registration Clinical Trials.gov We compared dilevalol ( an isomer of labetalol ) , 200 - 400 mg daily , against atenolol , 50 - 100 mg daily , in a double-blind , crossover , placebo-controlled trial with respect to effects on arterial distensibility ( measured as pulse wave velocity [ PWV ] ) and wave reflection ( assessed from carotid pressure wave contour ) . Twelve patients of mean age 58 years ( range 44 - 73 years ) with essential hypertension ( supine diastolic blood pressure 95 - 114 mm Hg ) took active therapy for 12 weeks , separated by a 2 - 4 week placebo period .  Carotid pressure waveforms were recorded noninvasively by applanation tonometry with a Millar micromanometer-tipped probe .  PWV was measured between carotid and femoral arteries ( aortic PWV ) , carotid and radial arteries ( arm PWV ) , and femoral and pedal arteries ( leg PWV ) . Early wave reflection was calculated from the ratio of the height of the peak of the carotid wave above its shoulder to the pulse pressure and was expressed as an augmentation index . Both drugs were equally effective in reducing brachial sphygmomanometric pressure and PWV in all three regions ( active vs. placebo , p less than 0.001 ) , but there was no significant difference between the two active therapies . However , the augmentation index ( averaged during the treatment period ) was significantly lower with dilevalol ( 19 % ) than with atenolol ( 28 % , p less than 0.01 ) , corresponding to a greater decrease of 5 - 8 mm Hg in carotid systolic pressure compared with the brachial artery . Although both drugs were equally effective in reducing arterial distensibility , the vasodilating action of dilevalol gave added benefit in reducing wave reflection , presumably through its vasodilatory effect on peripheral conduit arteries BACKGROUND Different blood pressure (BP)-lowering drugs could have different effects on central aortic pressures and thus cardiovascular outcome despite similar effects on brachial BP . The Conduit Artery Function Evaluation ( CAFE ) study , a sub study of the Anglo-Sc and inavian Cardiac Outcomes Trial ( ASCOT ) , examined the impact of 2 different BP lowering-regimens ( atenolol+/-thiazide-based versus amlodipine+/-perindopril-based therapy ) on derived central aortic pressures and hemodynamics . METHODS AND RESULTS The CAFE study recruited 2199 patients in 5 ASCOT centers . Radial artery applanation tonometry and pulse wave analysis were used to derive central aortic pressures and hemodynamic indexes on repeated visits for up to 4 years . Most patients received combination therapy throughout the study . Despite similar brachial systolic BPs between treatment groups ( Delta0.7 mm Hg ; 95 % CI , -0.4 to 1.7 ; P=0.2 ) , there were substantial reductions in central aortic pressures with the amlodipine regimen ( central aortic systolic BP , Delta4.3 mm Hg ; 95 % CI , 3.3 to 5.4 ; P<0.0001 ; central aortic pulse pressure , Delta3.0 mm Hg ; 95 % CI , 2.1 to 3.9 ; P<0.0001 ) . Cox proportional-hazards modeling showed that central pulse pressure was significantly associated with a post hoc-defined composite outcome of total cardiovascular events/ procedures and development of renal impairment in the CAFE cohort ( unadjusted , P<0.0001 ; adjusted for baseline variables , P<0.05 ) . CONCLUSIONS BP-lowering drugs can have substantially different effects on central aortic pressures and hemodynamics despite a similar impact on brachial BP . Moreover , central aortic pulse pressure may be a determinant of clinical outcomes , and differences in central aortic pressures may be a potential mechanism to explain the different clinical outcomes between the 2 BP treatment arms in ASCOT Antihypertensive agents may , even within the same class , exert variable effects on arterial stiffness variables .  Nebivolol could have a better impact than atenolol on arterial stiffness , by increasing the bioavailability of endothelium-derived nitric oxide . Angiotensin-converting enzyme inhibitors ( ACEIs ) and angiotensin receptor blockers ( ARBs ) increase plasma renin activity ( enhancing the production of angiotensin II via non-ACE-related pathways ) whereas aliskiren does not , potentially affecting central hemodynamics differently . We compared the effects of two renin-angiotensin-aldosterone system ( RAAS ) inhibitors ( quinapril and aliskiren ) and 2 beta-blockers ( atenolol and nebivolol ) on arterial stiffness variables . Treatment-naïve patients ( n = 72 ; 68.1 % males ; age , 47.6 ± 10.6 years ) with uncomplicated stage I-II essential hypertension were r and omly assigned to quinapril , aliskiren , atenolol , or nebivolol for 10 weeks . Central systolic and diastolic blood pressure ( BP ) , central pulse pressure ( PP ) , augmentation index ( AIx ) , and pulse wave velocity ( PWV ) were measured at baseline , 2 , and 10 weeks . The same measurements were performed in 20 normotensive subjects ( 65.0 % males ; age , 40.0 ± 8.9 years ) . Peripheral and central systolic and diastolic BP , peripheral PP , and PWV were significantly and similarly reduced by all agents . However , PWV continued to decline between the second and last visit in patients on quinapril and aliskiren but did not change in those on nebivolol or atenolol  . Central PP and AIx decreased in patients on quinapril , aliskiren , and nebivolol but did not change in those taking atenolol . The decrease in central PP and AIx did not differ between patients on quinapril , aliskiren , and nebivolol . Despite similar reductions in peripheral BP , atenolol is less effective than nebivolol and RAAS inhibitors in improving central pulsatile hemodynamics . Aliskiren exerts similar effects on markers of arterial stiffness  as quinapril . The clinical relevance of these differences remains to be established Background . Hypertension is common after liver transplantation . There are few published data on optimum treatment . Augmentation index ( AIx ) is a measure of arterial wave reflection determined by pulse wave analysis . Methods . Amlodipine was administered to 24 hypertensive liver transplant recipients . Thirteen patients intolerant of or unresponsive to amlodipine  were r and omized to a crossover study comparing bisoprolol with lisinopril . Results . With amlodipine  , systolic blood pressure ( SBP ) fell from  
    Output:
    