Peripheral arterial disease in patients with stages IV and V chronic renal failure

Abstract

Background: Cardiovascular disorders are frequently found among chronic renal failure (CRF) patients due to their higher susceptibility to develop atherosclerosis. However, peripheral arterial disease (PAD), that is associated with a high mortality rate, is not usually assessed in these patients. The aims of this study are to find out the prevalence of PAD affecting lower limbs in a population of CRF patients in stages IV/V, and to assess how much PAD determines the 5-year patient survival.

Methods: The study population (44 males and 29 females) was aged 58 +/- 15 years. They suffered from advanced CRF (18.6 +/- 6.1 ml/min creatinine clearance), but they were not on dialysis. These patients were sequentially referred initially to the predialysis unit over a period of 14 months. The vascular lesions were assessed by carotid and transcranial ultrasound, as well as by ankle-brachial index test (ABI). Routine 24 h blood and urine laboratory tests were performed for each patient. Cardiovascular morbidity and cardiovascular disease risk factors were evaluated through personal interview.

Results: Fourteen patients had an ABI index of less than 0.91 (PAD indicative), 11 of them also suffered from intermittent claudication. PAD affected significantly more males (P = 0.001) and diabetics (P = 0.001). Also, PAD prevalence was significantly higher in patients with a previous clinical record of coronary heart disease (P = 0.001), increased clinical record of cerebrovascular disease (P = 0.005), a thickness of the left ventricular posterior wall (P = 0.03) and lower cardiac ejection fraction (P = 0.02). PAD patients had a significantly different protein intake (P = 0.003), calcium-phosphorus product (P = 0.001), risk of coronary heart disease based on the Framingham score (P = 0.001) and 5-year survival rate (P = 0.004). There were no significant differences for PAD patients in terms of body mass index, creatinine clearance, lipid profile, Ca and P. Multivariate risk factor analysis revealed that a previous clinical record of coronary heart disease and diabetes increased the risk of developing PAD, as defined by ABI < 0.91. After 5 years, 21 patients (29%) had died: 64% of patients that suffered PAD (9/14) and 20% of the non-PAD population (12/59). The Cox proportional hazards model demonstrated that older age and a lower ABI increased the risk of death.

Conclusions: The present study, conducted on CRF patients in stages IV and V not undergoing dialysis, showed; (a) that a high percentage of these patients developed PAD (19%) or other vascular pathologies; (b) that there was an associated high mortality rate (29%) after 5 years; (c) that the 5-year mortality rate was significantly higher (P = 0.004) in PAD patients (64 vs 20%).