Cardiovascular outcomes in high-risk patients without heart failure treated with ARBs: a systematic review and meta-analysis

Differential Sex-Specific Effects of Angiotensin-Converting Enzyme Inhibition and Angiotensin Receptor Blocker Therapy on Arterial Function in Hypertension: CALIBREX Trial

BACKGROUND

Increased arterial stiffness is associated with adverse cardiovascular outcomes. We studied the sex-specific impact of angiotensin antagonists on vascular function in hypertension with the hypothesis that their effects on arterial stiffness may be variable in men and women.

METHODS

In 141 hypertensive participants with mild cognitive impairment (age 65.9±7.7, 57% female), candesartan (up to 32 mg, n=77) or lisinopril (up to 40 mg, n=64) were administered to achieve blood pressure <140/90 mm Hg. Pulse wave velocity, central pulse pressure, and central augmentation index were measured using applanation tonometry (SphygmoCor, Australia). Multivariate linear regression and mixed model analyses were performed using intention-to-treat and per protocol analyses for those completing the study.

RESULTS

Blood pressure reduction was similar among candesartan and lisinopril groups. Compared with candesartan, lisinopril therapy resulted in lower pulse wave velocity (0.5±0.8 versus -0.7±0.4 m/s, respectively; P=0.003) and central pulse pressure (-1±3 versus -7±4 mm Hg; P=0.03) after 1 year. There was a significant interaction by sex whereby the improvements in pulse wave velocity and central pulse pressure with lisinopril compared with candesartan were only observed in women. In contrast, there was greater improvement in augmentation index with candesartan compared with lisinopril (-4±7% versus -1.5±8%; P=0.05), with no sex differences.

CONCLUSIONS

Despite equipotent antihypertensive effects, lisinopril was more effective than candesartan at lowering arterial stiffness in women. In contrast, candesartan was more effective than lisinopril in improving pulse wave reflections in both sexes. These findings demonstrate differential sex-specific effects of renin-angiotensin system antagonists on arterial function in hypertension that may contribute to long-term cardiovascular and neurocognitive outcomes in this population.

Molecules and Mechanisms to Overcome Oxidative Stress Inducing Cardiovascular Disease in Cancer Patients

Reactive oxygen species (ROS) are molecules involved in signal transduction pathways with both beneficial and detrimental effects on human cells. ROS are generated by many cellular processes including mitochondrial respiration, metabolism and enzymatic activities. In physiological conditions, ROS levels are well-balanced by antioxidative detoxification systems. In contrast, in pathological conditions such as cardiovascular, neurological and cancer diseases, ROS production exceeds the antioxidative detoxification capacity of cells, leading to cellular damages and death. In this review, we will first describe the biology and mechanisms of ROS mediated oxidative stress in cardiovascular disease. Second, we will review the role of oxidative stress mediated by oncological treatments in inducing cardiovascular disease. Lastly, we will discuss the strategies that potentially counteract the oxidative stress in order to fight the onset and progression of cardiovascular disease, including that induced by oncological treatments.

Angiotensin-Converting Enzyme Inhibitors or Angiotensin Receptor Blockers in Patients Without Heart Failure? Insights From 254,301 Patients From Randomized Trials

OBJECTIVES

To compare the efficacy and safety of angiotensin-converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) in patients without heart failure.

PATIENTS AND METHODS

Meta-analysis of randomized trials identified using PubMed, Embase, and Cochrane Central Register of Controlled Trials searches from January 1, 1980, through April 13, 2015, of ACEis and ARBs compared with placebo or active controls and corroborated with head-to-head trials of ARBs vs ACEis. Outcomes were all-cause mortality, cardiovascular death, myocardial infarction (MI), angina, stroke, heart failure, revascularization, and new-onset diabetes.

RESULTS

Our search yielded 106 randomized trials that enrolled 254,301 patients. Compared with placebo, ACEis but not ARBs reduced the outcomes of all-cause mortality (ACEis vs placebo: relative risk [RR], 0.89; 95% CI, 0.80-1.00; ARBs vs placebo: RR, 1.01; 95% CI, 0.96-1.06; Pinteraction=.04), cardiovascular death (RR, 0.83; 95% CI, 0.70-0.99 and RR, 1.02; 95% CI, 0.92-1.14; Pinteraction=.05), and MI (RR, 0.83; 95% CI, 0.78-0.90 and RR, 0.93; 95% CI, 0.85-1.03; Pinteraction=.06). The meta-regression analysis revealed that the difference between ACEis and ARBs compared with placebo was due to a higher placebo event rate in the ACEis trials (most of these trials were conducted a decade earlier than the ARB trials) for the outcome of all-cause mortality (P=.001), cardiovascular death (P<.001), and MI (P=.02). Sensitivity analyses restricted to trials published after 2000 revealed similar outcomes with ACEis vs placebo and ARBs vs placebo (Pinteraction>.05). Head-to-head comparison trials of ARBs vs ACEis exhibited no difference in outcomes except for a lower risk of drug withdrawal due to adverse effects with ARBs (RR, 0.72; 95% CI, 0.65-0.81).

CONCLUSION

In patients without heart failure, evidence from placebo-controlled trials (restricted to trials after 2000), active controlled trials, and head-to-head randomized trials all suggest ARBs to be as efficacious and safe as ACEis, with the added advantage of better tolerability.

Comparative assessment of angiotensin II type 1 receptor blockers in the treatment of acute myocardial infarction: surmountable vs. insurmountable antagonist

BACKGROUND

The mechanisms of antagonism vary between the angiotensin II type 1 receptor blockers (ARBs): insurmountable antagonism and surmountable antagonism. Recent retrospective observational studies suggest that ARBs may not have equivalent benefits in various clinical situations. The aim of this study was to compare the effect of two categories of ARBs on the long-term clinical outcomes of patients with acute myocardial infarction (AMI).

METHODS

We analyzed the large-scale, prospective, observational Korea Acute Myocardial Infarction Registry study, which enrolled 2740 AMI patients. They divided by the prescription of surmountable ARBs or insurmountable ARBs at discharge. Primary outcome was major adverse cardiac events (MACEs), defined as a composite of cardiac death, nonfatal MI, and re-percutaneous coronary intervention, coronary artery bypass graft surgery.

RESULTS

In the overall population, the MACEs rate in 1 year was significantly higher in the surmountable ARB group (14.3% vs. 11.2%, p=0.025), which was mainly due to increased cardiac death (3.3% vs. 1.9%, p=0.031). Matching by propensity-score showed consistent results (MACEs rate: 14.9% vs. 11.4%, p=0.037). In subgroup analysis, the insurmountable ARB treatment significantly reduced the incidence of MACEs in patients with left ventricular ejection fraction greater than 40%, with a low killip class, with ST segment elevation MI, and with normal renal function.

CONCLUSIONS

In our study, insurmountable ARBs were more effective on long-term clinical outcomes than surmountable ARBs in patients with AMI.

Angiotensin-Converting Enzyme Inhibitors (ACEIs) and Angiotensin-Receptor Blockers (ARBs) in Patients at High Risk of Cardiovascular Events: A Meta-Analysis of 10 Randomised Placebo-Controlled Trials

Context. Whether angiotensin converting-enzyme inhibitors (ACEI) and angiotensin-receptor blockers (ARB) are useful in high risk patients without heart failure is unclear. We perform a meta-analysis of prospective randomized placebo-controlled ACEI or ARB trials studying patients with a combination of risk factors to assess treatment impact on all cause mortality, cardiovascular mortality, nonfatal myocardial infarction (MI) and stroke. Method. A PubMed search was made for placebo-controlled trials recruiting at least 1,200 high risk patients randomized to either ACEI or ARB, with follow-up of at least 2 years. Meta-analysis was performed using the RevMan 5 program and Mantel-Haenszel analysis was done with a fixed effects model. Results. Ten trials recruiting 77,633 patients were reviewed. All cause mortality was significantly reduced by ACEI (RR 0.89; P = 0.0008), but not by ARB treatment (RR 1.00; P = 0.89). Cardiovascular mortality and nonfatal MI were also reduced in the ACEI trials but not with ARB therapy. Stroke was significantly reduced in the ACEI trials (RR 0.75; P < 0.00001) and more modestly reduced in the ARB trials (RR 0.90; P = 0.01). Conclusion. ACEI treatment reduced stroke, nonfatal MI, cardiovascular and total mortality in high risk patients, while ARB modestly reduced stroke with no effect on nonfatal MI, cardiovascular and total mortality.

The effect of valsartan versus non-RAAS treatment on autoregulation of cerebral blood flow

BACKGROUND

Cerebral autoregulation (CA) is a protective mechanism which maintains the steadiness of the cerebral blood flow (CBF) through a broad range of systemic blood pressure (BP). Acute hypertension has been shown to reduce the cerebrovascular adaptation to BP variations. However, it is still unknown whether CA is impaired in chronic hypertension. This study evaluated whether a strict control of BP affects the CA in patients with chronic hypertension, and compared a valsartan-based regimen to a regimen not inhibiting the renin-angiotensin-aldosterone system (non-RAAS).

METHODS

Eighty untreated patients with isolated systolic hypertension were randomized to valsartan 320 mg or to a non-RAAS regimen during 6 months. The medication was upgraded to obtain BP <140/90 mm Hg. Continuous recordings of arterial BP and CBF velocity (transcranial Doppler) were performed during periods of 5 minutes, at rest, and at different levels of alveolar CO(2) pressure provided by respiratory maneuvers. The dominant frequency of CBF oscillations was determined for each patient. Dynamic CA was measured as the mean phase shift between BP and CBF by cross-spectral analysis in the medium frequency and in the dominant CBF frequency.

RESULTS

Mean ambulatory 24-hour BP fell from 144/87 to 127/79 mm Hg in the valsartan group and from 144/87 to 134/81 mm Hg in the non-RAAS group (p = 0.13). Both groups had a similar reduction in the central BP and in the carotido-femoral pulse wave velocity. The average phase shift between BP fluctuations and CBF response at rest was normal at randomization (1.82 ± 0.08 s), which is considered a preserved autoregulation and increased to 1.91 ± 0.12 s at the end of study (p = 0.45). The comparison of both treatments showed no significant difference (-0.01 ± 0.17 s vs. 0.16 ± 0.16 s, p = 0.45) for valsartan versus non-RAAS groups. The plasmatic level of glycosylated hemoglobin decreased in the valsartan arm compared to the non-RAAS arm (-0.23 ± 0.06 vs. -0.08 ± 0.07%, p = 0.07).

CONCLUSIONS

In elderly hypertensive men with isolated chronic systolic hypertension, CA seems efficient at baseline and is not significantly affected by 6 months of BP-lowering treatment. This suggests that the preventive effects of BP medication against stroke are not mediated through a restoration of the CA.

Comparing angiotensin II receptor blockers on benefits beyond blood pressure

The renin-angiotensin-aldosterone system (RAAS) is one of the main regulators of blood pressure, renal hemodynamics, and volume homeostasis in normal physiology, and contributes to the development of renal and cardiovascular (CV) diseases. Therefore, pharmacologic blockade of RAAS constitutes an attractive strategy in preventing the progression of renal and CV diseases. This concept has been supported by clinical trials involving patients with hypertension, diabetic nephropathy, and heart failure, and those after myocardial infarction. The use of angiotensin II receptor blockers (ARBs) in clinical practice has increased over the last decade. Since their introduction in 1995, seven ARBs have been made available, with approved indications for hypertension and some with additional indications beyond blood pressure reduction. Considering that ARBs share a similar mechanism of action and exhibit similar tolerability profiles, it is assumed that a class effect exists and that they can be used interchangeably. However, pharmacologic and dosing differences exist among the various ARBs, and these differences can potentially influence their individual effectiveness. Understanding these differences has important implications when choosing an ARB for any particular condition in an individual patient, such as heart failure, stroke, and CV risk reduction (prevention of myocardial infarction). A review of the literature for existing randomized controlled trials across various ARBs clearly indicates differences within this class of agents. Ongoing clinical trials are evaluating the role of ARBs in the prevention and reduction of CV rates of morbidity and mortality in high-risk patients.