Risk of Hospitalization for Cardiovascular Events with β-Blockers in Hypertensive Patients: A Retrospective Cohort Study

Beta-Blockers and Hypertension: Some Questions and Answers

INTRODUCTION

International guidelines have removed b-blockers from first-line treatment of hypertension, limiting their use to patients with compelling indications. The position of guidelines stems from the results of studies performed with the 1st and 2nd generation of b-blockers, which concluded that these drugs have lower cardiovascular protection, compared with other antihypertensive agents.

AIM

The aim of our mini review is to answer to some questions about the effect of b-blockers on hypertension and cardiovascular protection and if these effects are different from those of other antihypertensive drugs, particularly in young and elderly patients.

METHODS

We evaluated the relevant systematic reviews and meta-analyses, which reported the effectiveness of b-blockers on blood pressure and cardiovascular outcomes, compared with placebo/no treatment and with other antihypertensive agents.

RESULTS

Beta-blockers, decreased high blood pressure with no significant difference from other common antihypertensive agents. Moreover b-blockers, compared with placebo, lowered the risk of major cardiovascular outcomes, while, compared with other drug classes, the reported results are very heterogeneous. Therefore it is difficult, globally, to find a difference between b-blockers and other drug classes.

CONCLUSIONS

Rather than looking for differences in the cardiovascular protective effect between b-blockers and other antihypertensive agents, we have to consider the different pathophysiology of hypertension in young [sympathetic hyperactivity] and elderly patients [arterial stiffness, high aortic systolic pressure]. Considering these aspects, non-vasodilating b-blockers are preferred, as first-line, in young/middle aged hypertensive subjects, while vasodilating b-blockers, are most appropriate, in elderly patients, for the favourable hemodynamic profile.

Nebivolol and incident cardiovascular events in hypertensive patients compared with nonvasodilatory beta blockers

OBJECTIVE

Nonvasodilatory beta blockers are associated with inferior cardiovascular event reduction compared with other antihypertensive classes, and there is uncertainty about first-line use of beta blockers for hypertension in guidelines. The third generation vasodilatory beta blocker nebivolol has unique beneficial effects on central and peripheral vasculature. Our objective was to compare longitudinal cardiovascular outcomes of hypertensive patients taking nebivolol with those taking the nonvasodilatory beta blockers metoprolol and atenolol.

METHODS

We performed a retrospective cohort analysis of hypertensive adults in the University of Colorado health system, without preceding diagnosis of cardiovascular or cerebrovascular disease. The primary outcome was composite incident heart failure, stroke, myocardial infarction, angina, or coronary revascularization. Mahalanobis 1:2 distance matching and Cox proportional hazards regression was used. Matching and regression variables included baseline demographics, socioeconomic factors, medical insurance type, prescribing provider type, cardiovascular risk factors, Charlson comorbidity index, other medications, and follow-up duration.

RESULTS

After matching, patients were predominantly women (54%, 3085 of 5705) and non-Hispanic Caucasian (79%, 4534 of 5705), with median age of 58. In matched Cox regression analysis, nebivolol was associated with 17% reduction in incident cardiovascular events compared with all nonvasodilatory beta blockers [hazard ratio 0.83, 95% confidence interval (CI) 0.74-0.94, P  = 0.004], and 24% reduction compared with metoprolol (hazard ratio 0.76, CI 0.66-0.87, P = 0.0001).

CONCLUSION

The vasodilatory beta blocker nebivolol was associated with reduced incident cardiovascular events compared with nonvasodilatory beta blockers. Additional study of other beta blockers is necessary to determine if this is a vasodilatory beta blocker class effect or is specific to nebivolol.

http://links.lww.com/HJH/B916.

Diastolic dysfunction and impaired cardiac output reserve in dysmetabolic nonhuman primate with proteinuria

BACKGROUND

Cardiorenal complications are common in patients with dysmetabolism and diabetes. The present study aimed to examine if a nonhuman primate (NHP) model with spontaneously developed metabolic disorder and diabetes develops similar complications to humans, such as proteinuria and cardiac dysfunction at resting condition or diminished cardiac functional reserve following dobutamine stress echocardiography (DSE).

METHODS AND RESULTS

A total of 66 dysmetabolic and diabetic cynomolgus (Macaca fascicularis) NHPs were enrolled to select 19 NHPs (MetS) with marked metabolic disorders and diabetes (fasting blood glucose: 178 ± 18 vs. 61 ± 3 mg/dL) accompanied by proteinuria (ACR: 134 ± 34 vs. 1.5 ± 0.4 mg/mmol) compared to 8 normal NHPs (CTRL). Under resting condition, MetS NHPs showed mild left ventricular (LV) diastolic dysfunction (E/A: 1 ± 0.06 vs. 1.5 ± 0.13), but with preserved ejection fraction (EF: 65 ± 2 vs. 71 ± 3%) compared to CTRL. DSE with an intravenous infusion of dobutamine at ascending doses (5, 10, 20, 30 and 40 μg/kg/min, 7 min for each dose) resulted in a dose-dependent increase in cardiac function, however, with a significantly diminished magnitude at the highest dose of dobutamine infusion (40 μg/kg/min) in both diastole (E/A: -12 ± 3 vs. -38 ± 5%) and systole (EF: 25 ± 3 vs. 33 ± 5%) as well as ~42% reduced cardiac output reserve (COR: 63 ± 8 vs. 105 ± 18%, p < 0.02) in the MetS compared to CTRL NHPs.

CONCLUSION

These data demonstrate that MetS NHPs with cardiorenal complications: proteinuria, LV diastolic dysfunction and preserved LV systolic function under resting conditions displayed compromised cardiac functional reserve under dobutamine stress. Based on these phenotypes, this NHP model of diabetes with cardiorenal complications can be used as a highly translational model mimic human disease for pharmaceutical research.

A Critical Review of Nebivolol and its Fixed-Dose Combinations in the Treatment of Hypertension

β-Adrenergic receptor blockers (β-blockers) are well-known useful and cost-effective drugs for managing hypertensive patients with coronary heart disease, stroke, and heart failure. However, it is often difficult to use β-blockers for patients with asthma or chronic obstructive pulmonary disease (COPD). Moreover, most β-blockers negatively influence glucose or lipid metabolism. Nebivolol is a third-generation lipophilic β-1 receptor-selective blocker with nitric oxide-mediated vasodilatory effects, metabolically neutral and usually well tolerated by patients with asthma or COPD. Nebivolol has significant effects of reduction in central blood pressure and improvements in endothelial dysfunction and arterial stiffness. To summarize the merits and demerits of nebivolol in different clinical situations, we conducted a review using the word 'nebivolol' on Pubmed and Embase, limiting the search to hypertension, clinical trials, and meta-analyses. This review summarizes the clinical studies on nebivolol itself and on the combination of nebivolol with other antihypertensive drugs, such as hydrochlorothiazide, angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, and amlodipine. Most studies showed the safety and well-tolerated profile of nebivolol and the combination of nebivolol with other antihypertensive drugs, which suggests that new fixed combinations of nebivolol with other antihypertensive drugs would be useful for patients who are unable to tolerate traditional β-blockers.