When blood pressure is consistently high, it can lead to complications such as a heart attack (myocardial infarction) or stroke. Both peripheral arterial disease (PAD) and hypertension are associated with atherosclerosis, which is hardening of the arteries caused by deposits of fat, cholesterol and other substances inside the blood vessels. PAD is diagnosed when the blood supply to the legs is restricted causing pain and cramping that limits walking (intermittent claudication). It is measured based on the walking distance (on a treadmill) before onset of pain (claudication distance), or ankle brachial pressure index (ABPI). PAD can progress to pain at rest and critical limb ischaemia that requires revascularisation or amputation. Treatment of hypertension, to reduce cardiovascular events and death, needs careful consideration in people with PAD. Anti-hypertensive medications may worsen the PAD symptoms by reducing blood flow and supply of oxygen to the limbs, and may have long-term effects on disease progression.
The evidence from randomised controlled trials examining the risks and benefits of various anti-hypertensive drug classes on measures of PAD is lacking. We identified four controlled trials in people with symptomatic PAD where participants were randomised to receive an anti-hypertensive treatment for at least one month, or placebo, or no treatment. In one trial with 397 participants, that the ACE inhibitor, ramipril, was effective in reducing the number of cardiovascular events by 28% compared to placebo. In the other study using an ACE inhibitor, the 26 (48%) patients on perindopril showed a small increase in claudication distance but no change in ABPI and a reduction in maximal walking distance. In patients undergoing peripheral arterial angioplasty (procedure to open narrowed or blocked blood vessels), the results from one trial with 96 participants suggested that the calcium antagonist, verapamil, reduced restenosis at six months. In the fourth small study, peripheral arterial wall thickness was similar whether men received the thiazide diuretic, hydrochlorathiazide, or the alpha-adrenoreceptor blocker, doxazosin.