beta blockers in hypertension

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  • 1.Beta blockers are not recommended as initial treatment ofuncomplicated hypertension beta-blockers had a reduced ability to protect against stroke, though being equally effective for protection from coronaryevents and mortality Administration of beta-blockers is beneficial in patients with angina pectoris, heart failure and a recent myocardialinfarction

2. In a meta-analysis of over 24,000 hypertensive patients aged52-70 years, atenolol was foundinferior to other anti-hypertensive drugs with higher total mortality (RR 1.13, 1.021.25), cardiovascular mortality (RR 1.16, 1.00-1.34) andstroke (RR1.30, 1.12-1.50) in patients on atenololCarlberg B, Samuelsson O, Lindholm LH. Atenolol in hypertension : is it a wise choice? Lancet 2004; 364: 1684-89. 3. A recent Cochrane review of over 95,000 hypertensive patients in 13 trials showed that beta-blockers do not reduce mortality and are inferior to other antihypertensive drugs suggesting that they should not be initiating drugs in hypertensionWiysonge CS, Bradley HA, Volmink J, Mayosi BM, Mbewu A, Opie LH. Beta-blockers for hypertension. Cochrane Database Syst Rev. 2012; 11: CD002003. 4. The inferiority of beta-blockers compared with that of otherantihypertensive agents was established by the LIFE study and the ASCOT study They showed superiority of an ACE inhibitor and, a calciumantagonist over therapy initiated by a b-blocker as far as stroke (LIFE) or stroke and mortality (ASCOT) were concerned 5. In the LIFE study 9000 hypertensive patients with leftventricular hypertrophy were randomized to either losarten or atenolol Similar reduction in systolic and diastolic BP were achievedwith both drugs Despite similar BP reduction atenolol was associated with 25% higher incidence of stroke but not with higher incidenceof MI 6. There was 25% lower incidence of new onset diabetes in thelosartan group In the subgroup of patients with diabetes the 24% reduction in primary endpoint was linked with reduction in cardiovascularand total mortality 7. ASCOT trial Suggested that BP in the central aorta might bean explanation for increase stroke in beta blocker groupIn this trial atenolol based regimen was less efficacious inreducing central aortic pressure than amlodipine based regimen Williams Bet al: differential impact of blood pressure lowering drugs on central aortic pressure and clinicaL outcomes CAF study . CIRCULATION 113:1213,2006 8. The difference in central aortic pressure is largely explainedby heart rate lowering effect of beta blockers Slowing heart rate will increase central augmentation index and in turn diminish central BP lowering effect of betablockersWilliams B, Lacy PS. Impact of heart rate on central aortic pressures and hemodynamics: analysis from the CAFE (Conduit Artery Function Evaluation) study: CAFE-Heart Rate. J Am Coll Cardiol 2009;54:705713. 9. These findings cannot be directly extrapolated to other -blockers, such as nebivolol and carvedilol, which have vasodilating effect in the peripheral circulation and less heart-rateslowing effect in the heartImpact of Heart Rate on Central Hemodynamics and Stroke: A Meta-Analysis of -Blocker Trials Feng-Hua Ding1, Yan Li1, Li-Hua Li1, Ji-Guang Wang1 American Journal of Hypertension 26(1) January 2013 10. In a recent meta analysis of 9 trials (n = 754), -blockers were less efficacious in reducing cAI than all the other classes of drugs (8.6%,P < 0.001). Baseline-adjusted difference in HR between randomized groups was associated with cAI (7.0% increase for each 10 bpm decrease in HR, P = 0.02), which was associated with cSBP (1.2 mm Hg increase for each 1% increase in cAI, P = 0.009) 11. Beta blockers does not reduce cental aortic pressure equally They reduces heart rate and increase peripheral resistance so that the arterial wave reflection from the periphery returns during systole rather than during diastole This leads to systolic augmentation of BP Williams Bet al: differential impact of blood pressure lowering drugs on central aortic pressure and clinicaL outcomes CAF study . CIRCULATION 113:1213,2006 12. 1. 2. 3. 4. 5. 6.7.Beta-blockers are not a preferred initial therapy for uncomplicated hypertension. Beta-blockers may be considered in Angina pectoris Post-myocardial infarction Heart failure Supraventricular tachycardia Glaucoma Pregnancy with evidence of increased sympathetic drive. 13. Beta blockers increase the incidence of diabetes through a decrease in insulin sensitivity secondary to reduce skeletal muscle perfusion from peripheral vasoconstrictionIf therapy is initiated with a beta-blocker and a second drug is required, add a calcium-channel blocker rather than a thiazide-like diuretic to reduce the persons risk of developing diabetes. 14. BETA BLOCKERS IN HEART FALIURE 15. Beta blockers have been one of the mainstays of treatment because of their ability to reverse the neurohumoral effects of the sustained sympathetic nervous system activation with prognostic and symptomatic benefitsAlthough there are potential benefits of blocking all three adrenergic receptors ,most of the deleterious effects are mediated by beta1 receptors 16. Beta blockers are indicated in symptomatic and asymptomatic HF and a depressed EF