An atherosclerosis risk factor assessment program for patients with peripheral arterial occlusive disease

Effect of blood pressure lowering medications on leg ischemia in peripheral artery disease patients: A meta-analysis of randomised controlled trials

BACKGROUND

It has been suggested that anti-hypertensive medications may worsen leg ischemia in peripheral artery disease (PAD) patients. We undertook a meta-analysis to assess the effect of anti-hypertensive medications on measures of leg ischemia including maximum walking distance (MWD), pain free walking distance (PFWD) and ankle brachial pressure index (ABPI). A meta-regression was performed to evaluate whether the effect of the anti-hypertensive medications on mean arterial pressure (MAP) was associated with changes in ABPI, MWD or PFWD.

METHOD

A systematic literature search was performed to identify placebo controlled randomized control trials (RCT) testing anti-hypertensive medications, which reported baseline and follow-up measurements of: MAP and MWD, PFWD or ABPI in patients with intermittent claudication (IC) due to PAD.

RESULT

A meta-analysis was performed on 5 RCTs comprising a total of 180 and 127 patients receiving anti-hypertensive medications and placebo respectively. This analysis suggested that anti-hypertensive medication did not significantly affect MWD, PFWD or ABPI. In contrast, the meta-regression analysis showed that the reduction in MAP due to the anti-hypertensive drugs was positively correlated with increased MWD during follow-up (β = 8.371, p = 0.035). Heterogeneity across studies, as assessed by I2, was high. The follow-up period within the included trials was generally short with 3 out of 5 studies having a follow-up period of ≤ 6 weeks.

CONCLUSION

This study suggests that anti-hypertensive treatment does not worsen but may improve leg ischemia in PAD patients. Larger multicenter trials with longer anti-hypertensive treatment periods are required to clarify the effect of anti-hypertensives on leg ischemia in PAD patients.

Neurological and electrophysiological parameters as outcome measurements for peripheral arterial occlusive disease

BACKGROUND

Ischemic monomelic neuropathy is not an uncommon complication of peripheral arterial occlusive disease (PAOD). However, many investigators have used revascularization, limb salvage, and complete wound healing rates instead of neurologic and electrophysiological parameters as outcome measurements of PAOD. The aim of the study is to investigate the neurologic and electrophysiological parameters associated with PAOD and to find the ideal tools for assessing PAOD.

METHODS

A total of 38 PAOD patients (68.5 ± 8.1 years old, male:female = 32:6) with a total of 76 lower limbs were enrolled in the study. Primary outcomes were neurological symptoms scores (NSSs) and neurological impairment scores (NISs) for the lower extremities. Secondary outcomes were taken from nerve conduction studies (NCSs) and included the following: sensory nerve action potential (SNAP) amplitudes of the sural, superficial peroneal, and medial plantar nerves and the compound muscle action potential (CMAP) amplitudes of the posterior tibial and common peroneal nerves.

RESULTS

Female patients with old age, hypertension, low body weights, low body mass indices (BMIs), decreased ankle-brachial indices (ABIs), and poorer Fontaine classifications exhibited worse NSSs and NISs indices. Patients with old age, diabetes mellitus, hypertension, histories of social alcohol consumption, low body weights, low BMIs, and poorer Fontaine classifications exhibited decreased SNAP and CMAP amplitudes in the sensory and motor NCSs. Decreased ABI was associated with decreased SNAP amplitudes in the sensory NCSs.

CONCLUSIONS

Neurologic and electrophysiological parameters can be good tools for the assessment of PAOD. NSSs and NISs are particularly good candidates for outcome measures of PAOD.

Treatment of hypertension in peripheral arterial disease

BACKGROUND

Peripheral arterial disease (PAD) causes considerable morbidity and mortality. Hypertension is a risk factor for PAD. Treatment for hypertension must be compatible with the symptoms of PAD. Controversy regarding the effects of beta-adrenoreceptor blockade for hypertension in patients with PAD has led many physicians to stop prescribing beta-adrenoreceptor blockers. Little is known about the effects of other classes of anti-hypertensive drugs in the presence of PAD. This is the second update of a Cochrane review first published in 2003.

OBJECTIVES

To determine the effects of anti-hypertensive drugs in patients with both raised blood pressure and symptomatic PAD in terms of the rate of cardiovascular events and death, symptoms of claudication and critical leg ischaemia, and progression of atherosclerotic PAD as measured by ankle brachial index (ABI) changes and the need for revascularisation (reconstructive surgery or angioplasty) or amputation.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Cochrane Peripheral Vascular Diseases Group Specialised Register (last searched March 2013) and CENTRAL (2013, Issue 2).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of at least one anti-hypertensive treatment against placebo or two anti-hypertensive medications against each other, with interventions lasting at least one month. Trials had to include patients with symptomatic PAD.

DATA COLLECTION AND ANALYSIS

Data were extracted by one author (DAL) and checked by the other (GYHL). Potentially eligible studies were excluded when the results presentation prevented adequate extraction of data and enquiries to authors did not yield raw data.

MAIN RESULTS

Eight RCTs were included with a total of 3610 PAD patients. Four studies compared a recognised class of anti-hypertensive treatment with placebo and four studies compared two anti-hypertensive treatments with each other. Studies were not pooled due to the variation of the comparisons and the outcomes presented. Overall the quality of the available evidence was unclear, primarily as a result of a lack of detail in the study reports on the randomisation and blinding procedures and incomplete outcome data. Two studies compared angiotensin converting enzyme (ACE) inhibitors against placebo. In one study there was a significant reduction in the number of cardiovascular events in patients receiving ramipril (odds ratio (OR) 0.72, 95% confidence interval (CI) 0.58 to 0.91; n = 1725). In the second trial using perindopril (n = 52) there was a marginal increase in claudication distance but no change in ABI and a reduction in maximum walking distance. A trial comparing the calcium antagonist verapamil versus placebo in patients undergoing angioplasty (n = 96) suggested that verapamil reduced restenosis (per cent diameter stenosis (± SD) 48.0% ± 11.5 versus 69.6% ± 12.2; P < 0.01), although this was not reflected in the maintenance of a high ABI (0.76 ± 0.10 versus 0.72 ± 0.08 for verapamil versus placebo). Another study (n = 80) demonstrated no significant difference in arterial intima-media thickness (IMT) in men receiving the thiazide diuretic hydrochlorothiazide (HCTZ) compared to those receiving the alpha-adrenoreceptor blocker doxazosin (-0.12 ± 0.14 mm and -0.08 ± 0.13 mm, respectively; P = 0.66). A study (n = 36) comparing telmisartan to placebo found a significant improvement in maximum walking distance at 12 months with telmisartan (median (interquartile range (IQR)) 191 m (157 to 226) versus 103 m (76 to 164); P < 0.001) but no differences in ABI (median (IQR) 0.60 (0.60 to 0.77) versus 0.52 (0.48 to 0.67)) or arterial IMT (median (IQR) 0.08 cm (0.07 to 0.09) versus 0.09 cm (0.08 to 0.10)). Two studies compared the beta-adrenoreceptor blocker nebivolol with either the thiazide diuretic HCTZ or with metoprolol. Both studies found no significant differences in intermittent or absolute claudication distance, ABI, or all-cause mortality between the anti-hypertensives. A subgroup analysis of PAD patients (n = 2699) in a study which compared a calcium antagonist-based strategy (verapamil slow release (SR) ± trandolapril) to a beta-adrenoreceptor blocker-based strategy (atenolol ± hydrochlorothiazide) found no significant differences in the composite endpoints of death, non-fatal myocardial infarction or non-fatal stroke with or without revascularisation (OR 0.90, 95% CI 0.76 to 1.07 and OR 0.96, 95% CI 0.82 to 1.13, respectively).

AUTHORS' CONCLUSIONS

Evidence on the use of various anti-hypertensive drugs in people with PAD is poor so that it is unknown whether significant benefits or risks accrue. However, lack of data specifically examining outcomes in PAD patients should not detract from the overwhelming evidence on the benefit of treating hypertension and lowering blood pressure.

Treatment of hypertension in peripheral arterial disease

BACKGROUND

Peripheral arterial disease (PAD) causes considerable morbidity and mortality. Hypertension is a risk factor for PAD. Treatment for hypertension must be compatible with the symptoms of PAD. Controversy regarding the effects of beta-blockade for hypertension in patients with PAD has led many physicians to stop prescribing beta-blockers. Little is known about the effects of other classes of anti-hypertensive drugs in the presence of PAD. This is an update of a Cochrane review first published in 2003.

OBJECTIVES

To determine the effects of anti-hypertensive drugs on cardiovascular events and death, symptoms of claudication, critical leg ischaemia, progression of PAD and revascularisation or amputation in people with hypertension and PAD SEARCH STRATEGY: The Cochrane Peripheral Vascular Diseases Group searched their Specialised Register (last searched May 2009) and the Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, Issue 2). The authors studied abstracts of cardiology meetings.

SELECTION CRITERIA

Randomised controlled trials of at least one anti-hypertensive treatment against placebo, or two anti-hypertensive medications against each other, with interventions lasting at least one month. Trials had to include patients with symptomatic PAD.

DATA COLLECTION AND ANALYSIS

Data were extracted by one author (DAL) and checked by the other (GYHL). Eligible studies were excluded when results presentation prevented adequate extraction of data and enquiries to authors did not yield raw data.

MAIN RESULTS

Four studies were included. Two compared ACE inhibitors against placebo. In the HOPE study there was a significant reduction in the number of cardiovascular events in 168 patients receiving ramipril (OR 0.72, 95% confidence interval 0.58 to 0.91). In the second trial using perindopril in a small numbers of patients, there was a marginal increase in claudication distance but no change in ankle brachial pressure index (ABPI) and a reduction in maximum walking distance.The third trial in patients undergoing angioplasty suggested that the calcium antagonist verapamil reduced restenosis, although this was not reflected in the maintenance of a high ABPI. Another small study demonstrated no significant difference in arterial intima-media thickness with men receiving the thiazide diuretic hydrochlorathiazide compared to those receiving the alpha-adrenoreceptor blocker doxazosin.

AUTHORS' CONCLUSIONS

Evidence on various anti-hypertensive drugs in people with PAD is poor so that it is unknown whether significant benefits or risks accrue from their use. Lack of data specifically examining outcomes in PAD patients should not detract from the compelling evidence of the benefit of treating hypertension and lowering blood pressure.

Treatment of hypertension in peripheral arterial disease

BACKGROUND

Peripheral arterial disease (PAD) causes considerable morbidity and mortality. Hypertension is a risk factor for PAD. Therefore, treatment for hypertension must be compatible with the symptoms of PAD. Controversy regarding the effects of beta blockade for hypertension in patients with PAD has led many physicians to stop prescribing beta-blockers. Little is known about the effects of other classes of anti-hypertensive drugs in the presence of PAD.

OBJECTIVES

To determine the effects of anti-hypertensive drugs on the: cardiovascular events and death in patients with hypertension and PAD; symptoms of claudication and critical leg ischaemia; progression of PAD, and revascularisation, or amputations.

SEARCH STRATEGY

Trials were sought via the Specialised Register of the Cochrane Peripheral Vascular Diseases Group (last searched July 2003), the Cochrane Central Register of Controlled Trials (CENTRAL) (last searched Issue 2, 2003), and the NHS Database of Abstracts of Reviews of Effectiveness (DARE) (last searched August 2002). There were no language restrictions. Abstracts of cardiology meetings were studied. Reference lists of papers were also examined.

SELECTION CRITERIA

Randomised controlled trials of at least one anti-hypertensive treatment against placebo, or two anti-hypertensive medications against each other, with interventions lasting at least one month. Trials had to include patients with symptomatic PAD. Trials of poor quality and execution were excluded, as were cross-over trials.

DATA COLLECTION AND ANALYSIS

Data were extracted by one reviewer and checked by the other. Eligible studies were excluded when presentation prevented adequate extraction of data, and enquiries to authors did not yield the raw data.

MAIN RESULTS

Two studies were included in the review. In one trial using perindopril in small numbers of patients with PAD, there was a marginal increase in claudication distance (weighted mean difference (WMD) 8.0, 95% confidence interval (CI) -30.66 to 46.66), but no change in ankle brachial pressure index (ABPI), (WMD 0, 95% CI -0.14 to 0.14), and a reduction in walking distance (WMD -46, 95 % CI -169.24 to 77.24). In patients undergoing angioplasty, a second trial suggested that the calcium antagonist verapamil reduced restenosis, although this was not reflected in the maintenance of a high ABPI.

REVIEWER'S CONCLUSIONS

The evidence for various anti-hypertensive drug classes in PAD is poor, so that it is unknown whether significant benefit or risk accrues from their use. In view of this, no definite recommendations on use or avoidance can be made from the available data.

Peripheral vascular disease and hypertension: a forgotten association?

Peripheral vascular disease (PVD) is associated with a high cardiovascular morbidity and mortality. Intermittent claudication is the most common symptomatic manifestation of PVD, but is also an important predictor of cardiovascular death, increasing it by three-fold, and increasing all-cause mortality by two to five-fold. Hypertension is a common and important risk factor for vascular disorders, including PVD. Of hypertensives at presentation, about 2-5% have intermittent claudication, with this prevalence increasing with age. Similarly, 35-55% of patients with PVD at presentation also have hypertension. Patients who suffer from hypertension with PVD have a greatly increased risk of myocardial infarction and stroke. Apart from the epidemiological associations, hypertension contributes to the pathogenesis of atherosclerosis, the basic underlying pathological process underlying PVD. Hypertension, in common with PVD, is associated with abnormalities of haemostasis and lipids, leading to an increased atherothrombotic state. Nevertheless, none of the large antihypertensive treatment trials have adequately addressed whether a reduction in blood pressure causes a decrease in PVD incidence. There is therefore an obvious need for such outcome studies, especially since the two conditions are commonly encountered together.