Hypertension and peripheral artery disease

Peripheral artery diseases (PADs) have for a long time been unrecognized and underestimated by the cardiovascular community. This is remarkable as many aspects of PADs are quite similar to atherosclerosis – the most frequent cause of PAD – elsewhere in the body. However, progress in this respect has been made by the documentation that PAD, in particular artery disease in the lower extremity (LEAD) is accompanied by a very high risk for local but also systemic complications such as stroke and coronary events [1–3]. This is the case both in symptomatic as in asymptomatic patients [4]; at 5 years, 20% of intermittent claudication patients present with a myocardial infarction or stroke; mortality is 10–15% [4]. Fortunately, prognosis has improved by better insight in the disease and strong suggestions for prevention [3]. The article by Yannoutsos et al. that is published in this issue of the Journal [5] is dealing with the role of blood pressure (BP) in the management of patients with critical limb ischemia (CLI), the very advanced form of LEAD. It is well known that CLI carries a high risk for local complications but the role of BP in this context is not yet clarified. In this article [5], the predictive value of SBP and DBP at hospital admission on 3-month mortality is analysed in 297 patients with CLI who are waiting for a revascularization procedure. BP was recorded using an automated brachial sphygmomanometer before the revascularization procedure. A median of seven separate readings was used to represent BP of each individual patient. Mean age of the patients was 78 years; SBP and DBP of the whole group averaged 132 and 70 mmHg, respectively; 62% of the patients were known as treated hypertensives, 48% were diabetic. Thirty-four patients (11.4%) died, in most cases, from cardiovascular causes. Mean SBP and mean DBP were negatively correlated to mortality; in other words, a SBP below 135 mmHg was accompanied by a higher mortality rate. The results on BP and mortality in this study are surprising and could impact on several clinical decisions. Indeed, the relationship of BP to mortality seems to point in the opposite direction than generally seen in hypertensive patients in whom obviously higher BP values are related to more events; by contrast, in this study cohort, patients with lower BP had a higher mortality. It is not immediately clear what the best conclusions of such findings are for the clinical management of CLI patients. At first sight, the clinician facing low BP in such patients might be tempted to stop all antihypertensive drugs hoping to see BP increasing to higher values; by this way, the general condition of the patients might improve as well as blood flow to the ischaemic areas. However, the authors suggested to take a prudent position when observing such low BP and rather concluded that lower BP in these patients should be seen as a warning sign in general. The cause of the lower BP should be examined first before stopping blindly antihypertensive treatment. For example, in one-third of the patients included in this study, heart failure was present; obviously the immediate risk of heart failure is at least as high, probably higher than the lower BP by itself. Therefore, the cause of low BP – there might be several – should be examined and treated first. Obviously, one should be careful to draw too many conclusions from this single study. Even if the data are coming from 297 patients in one centre, what illustrates the great interest of that centre on BP in CLI, one would love to see and compare the clinical experience in other centres as well. Also the question on what the best antihypertensive therapy is in such patients, facing vascular intervention often at high age. Should we in this condition prefer short-acting drugs allowing for easier and better adaptation of treatment before, during and after intervention? Also, as many patients in CLI are treated hypertensives, eventual causes of hypertension should be detected: for example, in many of such patients, renal circulation is impaired. Information on the previous level of pressure in these patients is important as it is well known in the clinic that stopping or decreasing the dosage of antihypertensive drugs in patients with severe hypertension in the past, often is accompanied by a rapid and uncontrolled rise of pressure. The current article [5] illustrates again the role of cardiovascular risk factors and especially BP, in vascular patients and in this article, patients with CLI. It also is encouraging to see an article on this topic published in a well known journal on hypertension. Patients with peripheral arterial disease seem to accumulate multiple risk factors bringing them to the highest levels of total cardiovascular risk. On top of this, CLI patients often present with deterioration of their cardiovascular and general condition and should be given the best possible care to overcome this particular burden. ACKNOWLEDGEMENTS Conflicts of interest There are no conflicts of interest.